is cbd oil good for bowel movement

CBD Oil for Constipation

Constipation, which is defined by difficult bowel movements or fewer than three bowel movements in one week, is a very common digestive problem. It affects millions of people each year in the US alone, and it becomes more likely with old age, pregnancy, or certain medical conditions. Although constipation is a short-term problem in most cases, it can be a chronic problem. This often occurs when constipation is a symptom of a larger chronic condition, like irritable bowel syndrome (IBS). Regardless of how long- or short-term the symptoms are, constipation is normally quite unpleasant, and it should be treated as quickly as possible.

9 Best CBD Oil for Constipation in 2022

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An Overview: Constipation That Can Be Treated with CBD

There are three main types of constipation, and they all require different treatment:

  • Obstructive
  • Atonic
  • Spastic

Obstructive constipation is usually the only one that requires urgent medical treatment, as it is the result of a physical intestinal blockage. It can require powerful medication, manual removal of the obstruction, or even surgery. The other types of constipation, while unpleasant to experience, are usually less severe and treatable at home. Atonic constipation is caused by a lack of internal muscle and usually occurs in people with unhealthy habits, such as eating a fiber-poor diet or not drinking enough water.

Spastic constipation is caused by inflammation and irritation of the intestines, like what occurs in IBS. While atonic constipation is best treated with a healthy diet and exercise, spastic constipation can be treated or improved with CBD oil, and this treatment path is much safer and less likely to cause side effects than laxatives and other constipation medications. If you’re interested in this natural treatment for constipation, you can use our list of the top ten products to find high-quality CBD oil to improve your symptoms.

Things to Consider When Buying CBD for Constipation

It’s generally safe to use CBD for constipation, and even using it “wrong” isn’t likely to cause a lot of harm, but it’s still important to choose your product carefully. When looking for the right CBD oil for your situation, you should consider:

  • Type of CBD – CBD isolate and broad-spectrum CBD should both be safe to use to treat constipation. However, full-spectrum products should be avoided. These contain THC, which can cause or worse constipation, especially if your body is not used to metabolizing it.
  • Product quality – Even though CBD itself is safe, cannabis products are not regulated by the FDA, meaning quality and safety are not guaranteed. Some companies produce low-quality CBD products contaminated with unsafe compounds, knowing that no regulatory body will stop them from selling it. This is why it’s critical that you only buy third-party-tested CBD for your constipation; independent testing companies can verify whether the product is really what it says on the label.
  • Your location – Hemp-derived CBD is legal in many places, even where other cannabis products are not. Only a few US states do not allow CBD, and some countries also ban all forms of cannabis. However, you will not be able to use CBD to treat constipation if you live in or are visiting these locations, so check the local laws before making a decision.

CBD and Constipation: How It Works?

CBD oil can be useful for people suffering from constipation because it treats some of the causes of constipation as well as the symptoms. It increases the amount of anandamide in the body, which is a type of endocannabinoid that moderates pain and inflammation in irritated tissue. This anti-inflammatory effect can be particularly helpful with IBS symptoms and other types of spastic constipation.

Since constipation is a common side effect of many medications, including pain medications, CBD could also help to treat constipation by replacing the drug that is causing it. For example, CBD can be very effective at reducing pain, so if you are constipated due to use of painkillers, switching to CBD could solve the problem. Of course, before stopping or changing any current medications or treatment, you should consult your doctor.

More choices available

Precautions

While CBD is much safer than many man-made drugs and laxatives, you should be cautious when considering using CBD to treat constipation. Some of the things you should be wary of include:

  • Type of constipation – CBD is an effective treatment for spastic constipation, but it can aggravate or mask the symptoms of atonic and obstructive constipation, which could delay the treatment you need. For this reason, it’s recommended that you consult your doctor before using CBD for your constipation so that they can rule these conditions out.
  • Quality of product – As we mentioned earlier, buying a CBD product that has undergone third-party testing is a key step in treating constipation safely. Low-quality, potentially contaminated CBD may not improve your symptoms or cause new ones.
  • THC Content – Cannabis products that contain a significant amount THC, like full-spectrum products should not be used to treat constipation, even if they also contain CBD. THC may cause constipation by slowing the digestive system down. Instead, opt for an isolate or broad-spectrum product that contains less than 0.3% THC. This small amount will not be enough to have negative effects on your metabolism.

As long as you are careful about the product you buy and keep your doctor informed of your symptoms, CBD will allow you to treat constipation in a safe, natural way.

Side Effects

Side effects from CBD are rare and generally not serious, but some of the most common ones include diarrhea and other digestive problems. You don’t want to replace one bowel movement irregularity with another, so be aware of these symptoms and discontinue your use of CBD if it causes undesirable effects. If consuming CBD in an edible form, make sure you are not sensitive or allergic to any of the other ingredients to avoid side effects unrelated to the cannabis.

Conclusion

Thanks to its anti-inflammatory properties, its interaction with the endocannabinoid system, and its ability to replace conventional pain relievers, CBD can reduce or cure constipation and related digestive symptoms. Just like any other time you buy a CBD product, you’ll want to make sure you choose something that is high-quality and has been tested by a third-party company. This way, you can feel confident that you know what you are getting.

CBD should not be used to treat obstructive or atonic constipation, so if you know or suspect that constipation you are experiencing is one of these, avoid CBD treatment until you consult a doctor. Follow the recommended dosage for the product or the advice of a doctor to avoid further stomach upset or unusually loose stools. When taken as directed, CBD can treat constipation with greater efficacy and fewer side effects than conventional medication.

Can CBD Oil Cause Constipation?

Anyone can get constipation. Some people experience mild symptoms, while others have chronic symptoms.

Constipation can be debilitating, especially during a task that requires concentration, and it can also affect your mood.

CBD oil and constipation has been a hot topic lately, and people are wondering:

  • Can CBD oil cause constipation?
  • Can CBD help with constipation?

What causes constipation

Chronic constipation is defined as having less than three bowel movements per week. Mild constipation may only show a few symptoms which we’ll get into in a minute.

This is a common problem that affects around 20% of Americans. This has resulted in 8 million visits on average to the doctor every year. It can be caused by a variety of problems that haven’t been addressed.

Considering most people have busy lifestyles, it can be hard to manage things outside work such as diet, sleep, and other lifestyle factors.

The leading causes are mostly related to these things:

  • Foods you eat or don’t eat
  • Lifestyle choices
  • Medications

Symptoms

Constipation can happen in several ways. Chronic constipation is when you go to the bathroom less than three times per week.

The general symptoms of constipation include:

  • Trouble passing stool
  • Weird looking stool – hard or lumpy
  • Bowel movements are painful
  • Bloating

If you have chronic constipation, you may want to see a doctor. However, if you experience mild constipation, you can address the following before thinking about taking CBD oil.

How to treat constipation

Several different things usually treat constipation.

1. Drink more water

Being dehydrated is bad for many things, including bowel movements. It can make you constipated if you are regularly not drinking enough water.

2. Eat more fiber

People who are constipated rarely have any fiber in their food because they are afraid of passing gas. However, eating fiber increases the bulk and consistency of bowel movements. You may want to start including some more high fiber foods such as vegetables and whole grains.

Some foods cause constipation that you want to avoid. That’s why some people follow specific diets because they may be allergic to certain foods without even realizing, for example, Gluten.

3. Drinking coffee

Some people may experience the urge to go to the bathroom, especially caffeinated coffee. This works because coffee stimulates your gut and the muscles in your digestive system.

4. Probiotic

Taking probiotic supplements can help those who suffer from chronic constipation. People who have this problem have an imbalance of bacteria in their gut, which probiotics can help.

5. Avoid dairy

Did you know that 65% of the human population is lactose intolerant? If you eat high amounts of dairy, you may want to consider cutting it out from your diet. This could be the cause of your constipation.

What is CBD oil?

CBD oil is sold as a dietary supplement that derives from the cannabis plant.

When people hear cannabis, they associate it with marijuana. Marijuana is a strain type of cannabis that has high amounts of THC and little to no. However, CBD oil comes from the hemp strain of cannabis, which contains mostly CBD and less than 0.3% THC.

What’s the difference between CBD and THC?

Well, THC is the psychoactive chemical in cannabis that gets you high. CBD does not get you high at all.

How it works in the body

The body has something called an Endocannabinoid System (ECS). This consists of cannabinoid receptors that are activated once we ingest cannabis.

As CBD oil comes from cannabis, these receptors get activated, and we experience the effects of CBD. The main impact is general well-being and promoting homeostasis within the body.

Side effects

CBD oil does have some side effects. These include:

  • Diarrhea
  • Fatigue
  • Appetite changes and weight

There are little to no side effects, but the effects listed above only occur when you take extremely high doses. We’re talking drinking CBD oil like it’s cool-aid.

Some people may be sensitive to things like THC. Some CBD oil products like full-spectrum, which contains a trace of THC, may cause a reaction to those sensitive to THC. Products such as broad-spectrum CBD oil that contains no THC.

CBD oil vs. hemp seed oil – the differences

People often confuse CBD oil with hemp oil. They are not the same thing.

  • CBD oil – flowers, stalks, and leaves of the hemp strain of cannabis. This contains a high amount of CBD, which activated the Endocannabinoid System.
  • Hemp oil – only seeds of the hemp plant. They are used for things like cooking and lotions. It only contains traces of CBD.

Hemp seed oil doesn’t contain anywhere near as much CBD because only the seeds are extracted to make the oil. CBD oil consists of the whole plant, which makes it more effective in treating constipation.

When you buy hemp seed oil, a lot of companies get away with labeling their products as having high amounts of CBD, even though it doesn’t. It will say 1500mg of CBD when in reality, it probably contains less than 5mg of CBD.

The only way you can tell that the product does have real CBD in it is through a lab-test. A third party lab test shows how much CBD the product has, and it’s free from impurities such as heavy metals.

Can CBD oil cause constipation

There isn’t any reliable evidence that CBD oil causes constipation. We only have anecdotal evidence of users reporting digestive problems with some CBD oil products.

Not all CBD oils are made equal because CBD is an unregulated market. Some products have additives that can cause these digestive issues. Adverse side effects usually appear after using it for a while.

For those who have, constipation should buy products that are organic and use the least ingredients possible to avoid these side effects.

Some experts suggest that those with chronic constipation should take one week out of the month by not taking CBD oil at all. So this means you should use it for three weeks at a time, pause for a week, and then repeat the cycle.

Some carrier oils cause constipation

Carrier oils are oils that are used to help with the absorption. Some examples include hemp seed oil, MCT oil, and lavender oil.

Carrier oils play a role in constipation because they make up a vast percentage of CBD oil products. If a carrier oil is coming from MCT, for example, this oil is coming from a different plant. As this is not coming from hemp, you could have an adverse reaction, causing you to be constipated.

To reduce the risks of constipation, you should go for a carrier oil that comes from hemp. Look for ingredients that use hemp seed oil as their carrier oil.

CBD and constipation

CBD, at its core, provides calming effects. It works against the fight or flight responses of stress and anxiety, which keeps you calm in stressful situations. It also aids with inflammation and chronic pain.

The connection between CBD and constipation occurs here. With reduced stress, it quietens the mind and releases the muscles from too much tension. This sends a signal to the pain messages to be at ease.

Benefits of using CBD oil for constipation

CBD oil can help relieve the symptoms of constipation, such as stomach cramps and bloatedness. As these things can be painful, especially when trying to go to the bathroom, CBD can reduce pain and stress.

The main benefit is its ability to help relax your muscles, which will make it less painful when your bowels are moving.

Psychosomatic factors like stress are what cause irregular bowel movements.

CBD also acts on the serotonin receptors in the brains, which stimulate the release of a chemical called Anandamide. This reduces anxiety and relaxes the mind to deal with the stress of irregular bowel movements.

Final thoughts on CBD and constipation

So can CBD oil cause constipation? No, it actually helps.

CBD oil can be a helpful tool for dealing with the symptoms of constipation. However, other factors affect this condition, such as:

  • Lack of fiber in your diet
  • Stress
  • Poor eating habits
  • Lack of vitamins

Getting these in check with the help of CBD can make for a troubled gut. We recommend you to take CBD oil first thing in the morning and before going to the bathroom.

Make sure you pick a good quality product to ensure it doesn’t contain any ingredients that may make your constipation worse.

Frequently asked questions

Can CBD oil cause bowel problems?

It depends on the individual. Some people’s bodies don’t agree with everyone, so it will be silly to say that CBD oil won’t cause any problems at all. It’s similar to consuming food. Most people will respond well, but some people won’t.

Some of the most common side effects are nausea and gastrointestinal issues. This can lead to things like vomiting and diarrhea. This isn’t common, but it can happen due to a digestive problem.

Does CBD help with bowel movements?

CBD has a bunch of benefits, including bowel movements. Even though some people may experience side effects that do the opposite, the majority of people will see things like a decrease in anxiety, positive gut function, and relaxed muscles.

Can CBD oil help with constipation?

CBD oil interacts with the cannabinoids all around the body, including the gut. It doesn’t get rid of constipation completely. It helps with the symptoms mostly. Other factors have to be addressed before relying solely on CBD oil. Such as diet, stress, and other lifestyle factors.

Does CBD oil make you poop?

It doesn’t make you poop per se, but it does help your muscles to relax and reduce the stress associated with constipation. While it doesn’t treat constipation directly, it does help with the symptoms.

Effects of Hemp seed soft capsule on colonic ion transport in rats

Supported by the Clinical Medicine Development Project of Beijing Municipal Administration of Hospitals, No. ZYLX201411 .

Correspondence to: Sheng-Sheng Zhang, MD, Digestive Disease Center, Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, 23 Meishuguanhou Street, Beijing 100010, China. [email protected]

Telephone: +86-10-52176634 Fax: +86-10-52176634

Abstract

To investigate the effect of Hemp seed soft capsule (HSCC) on colonic ion transport and its related mechanisms in constipation rats.

METHODS

Sprague-Dawley male rats were randomly divided into three groups: normal group, constipation group and HSSC group. Rats in the constipation and HSSC groups were administrated loperamide 3 mg/kg per day orally for 12 d to induce the constipation model. Then, the HSSC group was given HSSC 0.126 g/kg per day by gavage for 7 d. The normal and constipation groups were treated with distilled water. After the treatment, the fecal wet weight and water content were measured. The basal short-circuit current (Isc) and resistance were measured by an Ussing Chamber. Besides the in vivo drug delivery experiment above, an in vitro drug application experiment was also conducted. The accumulative concentrations of HSSC (0.1 mg/mL, 0.5 mg/mL, 1.0 mg/mL, 2.5 mg/mL, 5.0 mg/mL, 10.0 mg/mL and 25.0 mg/mL) were added to the normal isolated colonic mucosa and the Isc was recorded. Further, after the application of either ion (Cl – or HCO3 – ) substitution, ion channel-related inhibitor (N-phenylanthranilic acid, glybenclamide, 4,4-diisothiocyano-2,2-stilbenedisulfonic acid or bumetanide) or neural pathway inhibitor [tetrodotoxin (TTX), atropine, or hexamethonium], the Isc induced by HSSC was also measured.

RESULTS

In the constipation group, the fecal wet weight and the water content were decreased in comparison with the normal group (P < 0.01). After the treatment with HSSC, the fecal wet weight and the water content in the HSSC group were increased, compared with the constipation group (P < 0.01). In the constipation group, the basal Isc was decreased and resistance was increased, in comparison with the normal group (P < 0.01). After the treatment with HSSC, the basal Isc was increased (P < 0.05) and resistance was decreased (P < 0.01) in the HSSC group compared with the constipation group. In the in vitro experiment, beginning with the concentration of 1.0 mg/mL, differences in Isc were found between the experimental mucosa (with HSSC added) and control mucosa. The Isc of experimental mucosa was higher than that of control mucosa under the same concentration (1.0 mg/mL, P < 0.05; 2.5-25 mg/mL, P < 0.01). After the Cl – or HCO3 – removal and pretreated with different inhibitors (cAMP-dependent and Ca 2+ -dependent Cl – channels, Na + -K + -2Cl – cotransporter (NKCC), Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger inhibitor), there were differences between experimental mucosa and control mucosa; the Isc of experimental mucosa was lower than that of control mucosa under the same concentration (P < 0.05). Meanwhile, after pretreatment with neural pathway inhibitor (TTX, atropine, or hexamethonium), there were no differences between experimental mucosa and control mucosa under the same concentration (P > 0.05).

CONCLUSION

HSSC ameliorates constipation by increasing colonic secretion, which is mediated via the coaction of cAMP-dependent and Ca 2+ -dependent Cl – channels, NKCC, Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger.

Core tip: In this study, we established a constipation model using the application of loperamide and found that Hemp seed soft capsule could improve the symptom of constipation. Further, it was found that the effect of Hemp seed soft capsule might be achieved by increasing colonic secretion, which is mediated via the combined action of cAMP-dependent and Ca 2+ -dependent Cl – channels, Na + -K + -2Cl – cotransporter, Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger. However, the submucosal neurons seemed to not play a key role in the process.

INTRODUCTION

Constipation is one of the most common gastrointestinal complaints in clinical practice. With the modern changes in living and working environments, constipation maintains a high incidence and greatly influences the life quality of patients. According to an epidemiological survey, the average incidence of constipation in the worldwide general population was 16%[1]. In China, the prevalence rate of constipation was 8.2% in the general population, being higher in the elderly population (18.1%) and pediatric population (18.8%)[2].

As reported, multiple factors (diet, lifestyle, certain medication, organic or functional diseases, etc) and various potential pathogeneses (disturbed intestinal motility, sensory and secretion, microbiota, etc) contribute to the occurrence and development of constipation. A variety of treatment methods have been adopted for constipation, such as lifestyle or dietary modification, secretagogues and prokinetics[3]. However, the current treatment options are limited due to various side effects, such as diarrhea, melanosis coli and so on[4,5].

In recent years, Traditional Chinese Medicine (TCM) has been reported to be effective in the treatment of constipation[6,7], and Hemp seed soft capsule (HSSC) is one of the safe and effective Chinese herbal medicines[8]. However, the treatment mechanism of HSSC is unclear, which restricts its widespread application. Intestinal secretion is known to play an important role in constipation[9]. Besides, Semen Cannabis as the monarch drug of HSSC was reported to possess rich fatty oil and stimulate intestinal mucosa secretion[10]. Hence, in the present study, we aimed to explore whether the regulation of intestinal secretion was a possible mechanism of HSSC in the improvement of constipation.

MATERIALS AND METHODS

Animals

Specific pathogen-free male Sprague-Dawley rats (250 g ± 10 g) were purchased from the Chinese People’s Liberation Army Military Medical Academy Experimental Animal Center. Animals were housed in the Institute of Basic Theory, China Academy of Chinese Medical Sciences. The level II-feeding condition maintains the room temperature at 23 °C-26 °C, the light /dark cycle of 12h/12h and relative humidity from 45% to 60%. All the animals were given free access to food and water.

Reagents and apparatus

Preparation of the Krebs solution involved NaCl 117 mmol/L, KCl 4.7 mmol/L, MgCl2 1.2 mmol/L, NaHCO3 24.8 mmol/L, KH2PO4 1.2 mmol/L, CaCl2 2.56 mmol/L, and glucose 11.1 mmol/L. For preparation of the Krebs solution without Cl – , the NaCl, KCl, MgCl2 and CaCl2 were replaced by sodium gluconate, potassium gluconate, magnesium gluconate and calcium gluconate, respectively. For preparation of the Krebs solution without HCO3 – , the NaHCO3 was replaced by NaCl and the solution was buffered with 10 mmol/L HEPES-free acid.

HSSC was acquired from Tianjin Central Pharmaceutical Co., LTD (Tianjin, China). N-Phenylanthranilic acid (DPC; 144509), glybenclamide (G0639), 4,4-diisothiocyano-2,2-stilbenedisulfonic acid (DIDS; D3514), bumetanide (B3023), and tetrodotoxin (TTX; T8024) were obtained from Sigma-Aldrich Co., Ltd (St. Louis, MO, United States). Atropine sulfate monohydrate (A800762) was purchased from Macklin Biochemical Co., Ltd (Shanghai, China). Hexamethonium bromide (H0481) was obtained from TCI Chemicals Co., Ltd (Tokyo, Japan).

Multichannel voltage-current clamp (VCC MC6) was purchased from Physiologic Instruments Corporation (San Diego, CA, United States). The bridge amplifier (ML228) and the recording and analysis system (Power Lab) were purchased from AD Instruments Corporation (New South Wales, Australia).

Animal groups and interventions

Twenty-four rats were randomly divided into three groups: normal group, constipation group and HSSC group. The constipation and HSSC groups were given oral administration of loperamide 3 mg/kg daily for 12 d[11,12]. The control rats were administered with the same volume of distilled water.

After the 12-d loperamide treatment, the rats in the HSSC group were given HSSC by gavage (0.126 g/kg per day). HSSC was water soluble and diluted into aqueous solution. The concentration of the stock solution was 1 g/mL. Whereas, the normal and constipation groups were treated with distilled water (2 mL/100 g per day). The interventions for all the groups were given for 7 consecutive days.

Fecal water content

After the treatment, the rats were placed in metabolic cages, individually. Fecal samples in 24 h were collected, weighed and dried. The weight of the samples before and after drying were made for measuring the fecal water content (%) using the following formula[13,14]: (wet weight – dry weight)/wet weight × 100%.

Tissue preparation

The distal colon (6-7 cm from the anus) was obtained and cut longitudinally along the mesenteric border. Then, the serosal and muscular layers were carefully separated from the mucosal and submucous layers with fine tweezers. The tissue preparations were cut into small sheets, with an area of more than 0.5 cm 2 .

Isc measurement after application of HSSC

Isc was the main evaluation index for colonic mucosa secretion. Ussing Chamber was the indispensable instrument for measuring Isc, which was conducted after first mounting the tissue preparations in the Ussing Chamber. In the experiment, the Krebs solution was circulated with 95% oxygen and 5% carbon dioxide, the pH was maintained at 7.35-7.45 and temperature was at 37 °C[15,16].

Two experiments were designed to detect the effect of HSSC on colonic mucosa secretion: in vivo drug delivery experiment and in vitro drug application experiment.

The in vivo drug delivery experiment involved intragastric administration of HSSC to constipation rats. Specifically, the tissues were left to incubate for 60 min and the voltage across the tissues was clamped to 0, then the basal Isc was measured (μA/cm 2 ). To measure the transmembrane resistance, 1 mV electrical stimulation was applied and the resistance was calculated according to Ohm’s Law (R = V/I).

The in vitro drug application experiment involved application of HSSC on normal isolated colonic mucosa. The final concentration of HSSC (0.1 mg/mL, 0.5 mg/mL, 1.0 mg/mL, 2.5 mg/mL, 5.0 mg /mL, 10.0 mg/mL and 25 mg/mL) was added into the serosal side for 10 min and the Isc curve was recorded. The Isc at each concentration (%) equaled (Isc maximum peak)/(basal Isc). In the control group, the same volume of normal saline was added as blank control.

Effect of HSSC on Isc after removal of Cl – or HCO3 – and pretreated with different inhibitors

When Cl – or HCO3 – was removed from the Krebs solution, or the colonic mucosa was pretreated with a nonselective Cl – channel blocker (DPC at 1 mmol/L), a cAMP-dependent Cl – channel blocker (glibenclamide at 1 mmol/L) or a Ca 2+ -dependent Cl – channel blocker (DIDS at 500 μmol/L) apically, a Na + -K + -2Cl – cotransporter inhibitor (bumetanide at 100 mol/L), a Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger inhibitor (DIDS at 200 μmol/L), a neural inhibitor (TTX at 1 μmol/L), a muscarinic receptor inhibitor (atropine at 1 μmol/L ) or a nicotinic receptor antagonist (hexamethonium at 100 μmol/L) basolaterally, then the HSSC (1.0 mg/mL, 2.5 mg/mL, 5.0 mg/mL and 10.0 mg/mL) was added consecutively. The Isc curve was recorded and its concentration (%) was calculated using the method mentioned above. In the Cl – or HCO3 – removal experiment, the normal Krebs solution was used as blank control, and in the inhibitor treatment experiment, the same volume of normal saline was used to replace the inhibitors as blank control. The above experiment was repeated 6 times, each using 6 different rats.

Statistical analysis

The statistical analyses were performed by using SPSS 17.0 software (SPSS, Chicago, IL, United States); data are presented as mean ± SEM. All the original data in the study were distributed normally and conformed to homogeneity of variance. Differences among the three groups were analyzed using one-way analysis of variance (commonly known as ANOVA) followed by the least-significant difference test to compare the differences between two groups. Differences between two groups were analyzed using the t-test. P < 0.05 was considered statistically significant.

RESULTS

Effects of HSSC on fecal index in constipation rats

In the constipation group, the fecal wet weight and water content were decreased compared with those in the normal group (P < 0.01). After the treatment with HSSC, the fecal wet weight and the water content were increased in the HSSC group, in comparison with the constipation group (P < 0.01) (Figure ​ (Figure1 1 ).

Effect of Hemp seed soft capsule on fecal index in constipation rats. Data are presented as mean ± SEM (n = 8). a P < 0.01 vs normal group; b P < 0.01 vs constipation group.

Effects of HSSC on colonic mucosa secretion

In the constipation group, the basal Isc was decreased and the resistance was increased compared to the normal group (P < 0.01). After treatment with HSSC, the basal Isc was increased (P < 0.05) and the resistance was decreased (P < 0.01) in the HSSC group, in comparison with the constipation group (Figure ​ (Figure2A 2A ).

Effect of Hemp seed soft capsule on colonic mucosa secretion. A: In constipation rats (mean ± SEM, n = 8). b P < 0.01 vs normal group; c P < 0.05, d P < 0.01 vs constipation group; B: In normal isolated colonic mucosa (mean ± SEM, n = 6); C: Representative Isc trace in experimental group and control group. a P < 0.05, b P < 0.01 vs control group.

HSSC at cumulative concentrations from 0.1 mg/mL to 25 mg/mL (experimental group), increased Isc dose-dependently, which was not noted in the control group. As shown in Figure ​ Figure2B, 2B , starting from the concentration of 1.0 mg/mL, the difference in Isc was found to be significant between the experimental group and the control group. The Isc in the experimental group was higher than that in the control group at the same concentration (1.0 mg/mL, P < 0.05; 2.5-25 mg/mL, P < 0.01).

Effects of Cl – and HCO3 – on the secretagogue role of HSSC

When Cl – or HCO3 – was removed from the Krebs solution (-Cl – or -HCO3 – group), the Isc induced by the effective concentration of HSSC (1.0 mg/mL, 2.5 mg/mL, 5.0 mg/mL or 10.0 mg/mL) in the -Cl – or -HCO3 – group was lower than that in the +Cl – or +HCO3 – group (1.0 mg/mL-2.5 mg/mL, P < 0.05; 5.0 mg/mL-10.0 mg/mL, P < 0.01) (Figure ​ (Figure3 3 ).

Effect of Cl – and HCO3 – on the secretagogue role of Hemp seed soft capsule. Data are presented as mean ± SEM (n = 6). A: When Cl – was removed from the Krebs solution. The effect of Hemp seed soft capsule on colonic mucosa secretion was determined; B: When HCO3 – was removed from the Krebs solution. The effect of Hemp seed soft capsule on colonic mucosa secretion was determined. a P < 0.05, b P < 0.01 vs +Cl – group or +HCO3 – group.

Effects of Cl – channel on the secretagogue role of HSSC

The experimental mucosa was pretreated apically with the nonselective Cl – channel blocker DPC (+DPC group), cAMP-dependent Cl – channel blockers glibenclamide (+glibenclamide group) or Ca 2+ -dependent Cl – channel blocker DIDS (+apical DIDS group) for 30 min. The control mucosa was pretreated with the same volume of normal saline (-DPC group, -glibenclamide group, -apical DIDS group, respectively). After that, the effective concentration of HSSC (1.0 mg/mL, 2.5 mg/mL, 5.0 mg/mL or 10.0 mg/mL) was added to solicit the Isc response. As shown in Figure ​ Figure4, 4 , at the concentrations of 1.0 mg/mL, 2.5 mg/mL, 5.0 mg/mL and 10.0 mg/mL, the Isc in the +DPC group was lower than that in the -DPC group (1.0 mg/mL-2.5 mg/mL, P < 0.05; 5.0 mg/mL-10.0 mg/mL, P < 0.01). At the concentration of 2.5 mg/mL, 5.0 mg/mL and 10.0 mg/mL, the Isc in the +glibenclamide group was lower than that in the -glibenclamide group (2.5 mg/mL, P < 0.05; 5.0 mg/mL-10.0 mg/mL, P < 0.01). At the concentration of 5.0 mg/mL and 10.0 mg/mL, the Isc in the +apical DIDS group was lower than that in the -apical DIDS group (5.0 mg/mL, P < 0.05; 10.0 mg/mL, P < 0.01).

Effect of Cl – channel on the secretagogue role of Hemp seed soft capsule. Data are presented as mean ± SEM (n = 6). A: Pretreated with nonselective Cl – channel blocker DPC; B: Pretreated with cAMP-dependent Cl – channel blocker glibenclamide; C: Pretreated with Ca 2+ -dependent Cl – channel blocker DIDS. a P < 0.05, b P < 0.01 vs -DPC group, -glibenclamide group or -apical DIDS group.

Effects of Na + -K + -2Cl – cotransporter on the secretagogue role of HSSC

The experimental mucosa was pretreated with the Na + -K + -2Cl – cotransporter inhibitor bumetanide (+bumetanide group); the control mucosa was pretreated with the same volume of normal saline (-bumetanide group). After that, the effective concentration of HSSC (1.0 mg/mL, 2.5 mg/mL, 5.0 mg/mL or 10.0 mg/mL) was added to solicit the Isc response. As shown in Figure ​ Figure5, 5 , at the concentrations of 2.5 mg/mL, 5.0 mg/mL and 10.0 mg/mL, the Isc in the +bumetanide group was lower than that in the -bumetanide group (2.5 mg/mL, P < 0.05; 5.0 mg/mL-10.0 mg/mL, P < 0.01).

Effect of Na + -K + -2Cl – cotransporter on the secretagogue role of Hemp seed soft capsule. Data are presented as mean ± SEM (n = 6). a P < 0.05, b P < 0.01 vs -bumetanide group.

Effects of Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger on the secretagogue role of HSSC

The experimental mucosa was pretreated with the Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger inhibitor (+basolateral DIDS group); the control mucosa was pretreated with the same volume of normal saline (-basolateral DIDS group). After that, the effective concentration of HSSC (1.0 mg/mL, 2.5 mg/mL, 5.0 mg/mL or 10.0 mg/mL) was added to solicit the Isc response. As shown in Figure ​ Figure6, 6 , at the concentrations of 5.0 mg/mL and 10.0 mg/mL, the Isc in +bumetanide group was lower than that in the -bumetanide group (5.0 mg/mL, P < 0.05; 10.0 mg/mL, P < 0.01).

Effect of Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger on the secretagogue role of Hemp seed soft capsule. Data are presented as mean ± SEM (n = 6). a P < 0.05, b P < 0.01 vs -basolateral DIDS group.

Effects of neural pathway on the secretagogue role of HSSC

The experimental mucosa was pretreated with the neural inhibitor TTX (+TTX group), muscarinic receptor inhibitor atropine (+atropine group) or nicotinic receptor antagonist hexamethonium (+hexamethonium group); the control mucosa was pretreated with the same volume of normal saline (-TTX group, -atropine group, -hexamethonium group, respectively). After that, the effective concentration of HSSC (1.0 mg/mL, 2.5 mg/mL, 5.0 mg/mL or 10.0 mg/mL) was added to solicit the Isc response. As shown in Figure ​ Figure7, 7 , at each concentration, there was no difference between the experimental group (+TTX group, +atropine group, +hexamethonium group) and the control group (-TTX group, -atropine group, -hexamethonium group) (P > 0.05).

Effects of neural pathway on the secretagogue role of Hemp seed soft capsule. Data are presented as mean ± SEM (n = 6). A: Pretreated with neural inhibitor tetrodotoxin; B: Pretreated with muscarinic receptor inhibitor atropine; C: Pretreated with nicotinic receptor antagonist hexamethonium.

DISCUSSION

In our study, HSSC was found to increase the fecal wet weight and water content in constipation rats; meanwhile, colonic secretion was increased, possibly attributable to the combined action of cAMP-dependent and Ca 2+ -dependent Cl – channels, NKCC, Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger. However, the submucosal neurons, especially the cholinergic neurons, might play little or no role in the secretagogue role of HSSC.

HSSC is developed from the ancient traditional prescription “Hemp seed pills”, which consists of Semen Cannabis, Magnolia officinalis, Fructus Aurantii Immaturus, Radix Paeoniae Alba, Almond and Rheum rhabarbarum. The Hemp seed pill is a representative prescription of TCM in the treatment of constipation, in which Semen Cannabis as the monarch drug plays the role of Runchang Tongbian[17]. A series of clinical trials have confirmed the efficiency and safety of HSSC in the treatment of constipation[18,19]. In our study, we established a rodent model of constipation in which the fecal wet weight and water content were decreased and found that HSSC increased the fecal wet weight and water content; these findings confirmed that the HSSC could improve the stool properties in constipation rats.

As research progresses, the pharmacological properties of HSSC have been gradually revealed and the therapeutic mechanisms of HSSC for constipation have been partly clarified. Animal experimental studies have confirmed that HSSC could obviously increase the intestinal motility, fecal pellets and weight in constipation rats[20,21]. Further, in rabbits, the intestinal contractile frequency and amplitude were found to be increased after intragastric administration of Hemp seed pills. These previous findings suggested that HSSC might play a laxative effect by regulating the intestinal motility and gastrointestinal hormonal secretions, findings which were consistent with the pathophysiologies of constipation.

Constipation is a common clinical complaint caused by multiple physiological changes. In addition to the above-mentioned intestinal motility and gastrointestinal hormones, the imbalance of intestinal water and electrolytes has also been recognized as one of the most important pathophysiologies[22]. However, it hasn’t been reported whether HSSC could regulate the intestinal epithelium electrolyte secretion. In our study, HSSC was found to cause an upward Isc response and to have a role of secretagogue.

It is well known that under normal conditions, the Cl – and HCO3 – transport in the colon can generate an osmotic driving force for water. The components of Cl – secretion have been elaborated by Frizzell et al[23]: the apical cAMP-dependent and Ca 2+ -dependent Cl – channels (CaCC), basolateral NKCC are the main participants for the Cl – secretion; the HCO3 – transport is regulated by the Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger. In our experiment, it was found that when the Cl – and HCO3 – was removed from the normal Krebs solution, the Isc response induced by HSSC was reduced, suggesting that Cl – and HCO3 – participated in the ionic regulation of HSSC. Further, the pretreatment of colonic epithelium with the inhibitors of Cl – and HCO3 – channels inhibited the Isc response induced by HSSC, suggesting that HSSC regulated the anionic transport through the cAMP-dependent and Ca 2+ -dependent Cl – channels, NKCC, Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger.

As reported, anion secretion can be regulated by neural and non-neural pathways[24]. In the neural pathway, acetylcholine is one of the most important neurotransmitters that mediates intestinal secretion[25]. To determine the role of submucosal neurons, especially the cholinergic neurons, on secretagogue effect of HSSC, the neural inhibitor TTX, muscarinic receptor inhibitor atropine or nicotinic receptor antagonist hexamethonium was used to pretreat the mucosa/submucosa preparation; we found that there was no difference between experimental mucosa and control mucosa, which implied that the secretagogue effect of HSSC seemed not to be dependent on the submucosal nervous system.

In conclusion, the effect of HSSC on constipation was achieved by regulating the colonic secretion, which was mediated via cAMP-dependent and Ca 2+ -dependent Cl – channels, NKCC, Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger.

ARTICLE HIGHLIGHTS

Research background

Constipation is one of the most common gastrointestinal disorders, which maintains a high incidence rate and greatly influences the life quality of patients. As reported, multiple factors and potential pathogenesis contribute to the occurrence and development of constipation. And, a variety of treatment methods have been adopted for constipation, including Traditional Chinese Medicine, in which Hemp seed soft capsule is one of the safe and effective Chinese patent medicines. However, the treatment mechanisms of Hemp seed soft capsule have been unclear, which restricts its popularization and application. Hence, the exploration of possible mechanisms about Hemp seed soft capsule for treating constipation is necessary.

Research motivation

This study aimed to investigate the effect of Hemp seed soft capsule on colonic ion transport and its related mechanisms in constipation rats, the findings of which will have an important significance for clarifying the pharmacological effect of Traditional Chinese Medicine.

Research objectives

The main objective of the study was to explore whether the regulation of the intestinal secretion was the possible mechanism of Hemp seed soft capsule for treating constipation. This research provided a new thought for us to study Hemp seed soft capsule, and more molecules related to the colonic secretion could be discussed in the future.

Research methods

The constipation rats were induced by oral administration of loperamide (3 mg/kg per day for 12 d). The Hemp seed soft capsule group was given Hemp seed soft capsule by gavage (0.126 g/kg per day for 7 d). The normal and constipation groups were treated with the same volume of distilled water. After treatment, the fecal wet weight and water content were measured. The basal short-circuit current (Isc) and resistance were acquired by an Ussing Chamber. Further, after the ion substitution or inhibitor application, the Isc induced by Hemp seed soft capsule was also measured.

The statistical analyses were performed by using SPSS 17.0 software and the differences among the three groups were analyzed using one-way analysis of variance followed by least-significant difference test to compare the differences between two groups. The differences among the two groups were analyzed using t-test. P < 0.05 was considered statistically significant.

Research results

In this study, it was found that Hemp seed soft capsule could increase the fecal wet weight and water content in constipation rats. Meanwhile, Hemp seed soft capsule could increase colonic secretion, and after the application of cAMP- dependent or Ca 2+ – dependent Cl – channels inhibitor, NKCC inhibitor, Na + -HCO3 – cotransporter inhibitor or Cl – /HCO3 – exchanger inhibitor, the colonic secretion induced by HSSC were decreased in experimental group than that in the control group, which demonstrated that cAMP- dependent and Ca 2+ – dependent Cl – channels, Na + -K + -2Cl – cotransporter (NKCC), Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger may participate in the HSSC treatment. Meanwhile, after pretreatment with a neural pathway inhibitor (tetrodotoxin, atropine or hexamethonium), there were no differences between experimental mucosa and control mucosa, which implied that the secretagogue effect of HSSC was not dependent on the submucosal nervous system.

Though some results were obtained, the effect of Hemp seed soft capsule on real-time ion current and expression of ion channel protein should be explored in further studies, which will also be important for exploring the specific targets.

Research conclusions

The secretagogue effect of Hemp seed soft capsule for constipation may be achieved via the combined action of cAMP-dependent and Ca 2+ -dependent Cl – channels, NKCC, Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger. However, the submucosal neurons seem to not play a key role in the process. Decreased colonic secretion is found in constipation rats and Hemp seed soft capsule can reverse it. Besides, Cl – and HCO3 – participate in the regulative process. The effect of Hemp seed soft capsule for constipation can be achieved by increasing colonic secretion, which is related with the coaction of cAMP-dependent and Ca 2+ -dependent Cl – channels, NKCC, Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger. The discoveries in this study imply that Cl – , HCO3 – and related channels/cotransporters/exchangers participate in the effect of HSSC on constipation.

The new hypotheses proposed in this study is that regulation of the intestinal secretion was the possible mechanism of Hemp seed soft capsule for treating constipation. Ussing Chamber is the acknowledged method, although it is new, to be used in the discovery of the Hemp seed soft capsule therapeutic mechanism. Hemp seed soft capsule can increase the fecal wet weight and water content in constipation rats, while the colonic secretion is increased. Besides, cAMP-dependent and Ca 2+ -dependent Cl – channels, NKCC, Na + -HCO3 – cotransporter and Cl – /HCO3 – exchanger are involved in the effect of Hemp seed soft capsule on colonic secretion. The effect of Hemp seed soft capsule on constipation can be achieved by regulating the colonic secretion, which is related with cAMP-dependent and Ca 2+ -dependent Cl – channels, NKCC, Na + -HCO3 – cotransporter or Cl – /HCO3 – exchanger. Hemp seed soft capsule may increase the fecal water content in constipation patients and can be used as an effective laxative in clinical practice.

Research perspectives

In the study, we found Hemp seed soft capsule could relieve the symptom of constipation and increase the colonic secretion, which implied that the effect of Hemp seed soft capsule on constipation may be achieved by regulating colonic secretion. Further, it was found that Cl – and HCO3 – participated in the process, mediated via the related channels/cotransporters/exchangers. But, several questions remain unanswered, all of which can be discussed in the future (e.g., what specific pathways, receptors or molecules may be involved in the effect of Hemp seed soft capsule on colonic secretion, such as the 5-HT/5-HTR pathway or the dopamine pathway, or what structural and functional changes can be found in the ion transport protein on the effect of Hemp seed soft capsule, as the expression of cystic fibrosis transmembrane conductance regulator (CFTR, a cAMP- dependent Cl – channel) protein).

In further studies, we will focus on the effect of Hemp seed soft capsule on Cl – current and CFTR protein in constipation rats. The methods of patch-clamp and short-circuit current will be used to measure the Cl – current. Immunofluorescence will be used to investigate the location and expression of the CFTR protein. Finally, western blot and PCR will be conducted to evaluate the expression of CFTR protein and phosphorylated CFTR protein.

Footnotes

Manuscript source: Unsolicited manuscript

Specialty type: Gastroenterology and hepatology

Country of origin: China

Peer-review report classification

Grade A (Excellent): 0

Grade B (Very good): B

Institutional review board statement: The study was reviewed and approved by the Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University Review Board.

Institutional animal care and use committee statement: All procedures involving animals were reviewed and approved by the Institute of Basic Theory, China Academy of Chinese Medical Sciences Ethics Committee (No. 20160905).

Conflict-of-interest statement: None of the authors declared any conflicts of interest related to this study.

Data sharing statement: No additional data were available.

Peer-review started: July 20, 217

First decision: August 21, 2017

Article in press: September 19, 2017

P- Reviewer: Akiba Y, Liu S S- Editor: Qi Y L- Editor: Filipodia E- Editor: Huang Y

Contributor Information

Xiao-Fang Lu, Digestive Disease Center, Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, Beijing 100010, China. [email protected]

Meng-Di Jia, Digestive Disease Center, Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, Beijing 100010, China.

Sheng-Sheng Zhang, Digestive Disease Center, Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, Beijing 100010, China.

Lu-Qing Zhao, Digestive Disease Center, Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University, Beijing 100010, China.