Effects of Hypericum perforatum extract on rat irritable bowel syndrome

Protective and therapeutic potential of melatonin against intestinal diseases: updated review of current data based on molecular mechanisms

INTRODUCTION

Intestinal diseases, a leading global cause of mortality and morbidity, carry a substantial socioeconomic burden. Small and large intestines play pivotal roles in gastrointestinal physiology and food digestion. Pathological conditions, such as gut dysbiosis, inflammation, cancer, therapy-related complications, ulcers, and ischemia, necessitate the urgent exploration of safe and effective complementary therapeutic strategies for optimal intestinal health.

AREAS COVERED

This article evaluates the potential therapeutic effects of melatonin, a molecule with a wide range of physiological actions, on intestinal diseases including inflammatory bowel disease, irritable bowel syndrome, colon cancer, gastric/duodenal ulcers and other intestinal disorders.

EXPERT OPINION

Due to anti-inflammatory and antioxidant properties as well as various biological actions, melatonin could be a therapeutic option for improving digestive disorders. However, more researches are needed to fully understand the potential benefits and risks of using melatonin for digestive disorders.

A double-blind randomized clinical trial of Dracocephalum kotschyi Boiss. in the patients with diarrhea-predominant irritable bowel syndrome

Background and purpose

Irritable bowel syndrome (IBS) is a disease that shows its impacts on many populations worldwide. It is known as a functional disorder of the gastrointestinal tract followed by diarrhea and fecal inconsistency. Due to the lack of treatment in the allopathic medicine system for IBS, people in the western world use different herbs as alternative medicine. In the present study, we evaluated the dried extract of Dracocephalum kotschyi against IBS.

Experimental approach

In a randomized, double-blinded, placebo-controlled clinical trial, 76 diarrhea-predominant IBS patients were randomly assigned to two equal groups: the control group (given the placebo capsule containing 250 mg of dibasic calcium phosphate) and the treatment groups (given the capsule containing 75 mg of the dry extract of D. kotschyi and 175 mg of dibasic calcium phosphate as filler). The study was conducted based on Rome III criteria. We studied symptoms included in Rome III criteria and divided the study into the duration of drug administration and four weeks after drug administration. These groups were compared with those of the control group.

Findings/Results

Significant improvements were found in the quality of life, temperament, and IBS symptoms throughout the treatment duration. Quality of life, temperature, and IBS symptoms were slightly decreased in the treatment group 4 weeks after stopping the treatment. While concluding the study, we found D. kotschyi effective against IBS.

Conclusion and implications

Whole extract of D. kotschyi modulated symptoms of IBS patients and improved their quality of life.

Molecular Evidence on the Inhibitory Potential of Metformin against Chlorpyrifos-Induced Neurotoxicity

Chlorpyrifos (CPF) is an organophosphorus (OP) pesticide, resulting in various health complications as the result of ingestion, inhalation, or skin absorption, and leads to DNA damage and increased oxidative stress. Metformin, derived from Galega officinalis, is reported to have anti-inflammatory and anti-apoptotic properties; thus, this study aimed to investigate the beneficial role of metformin in neurotoxicity induced by sub-acute exposure to CPF in Wistar rats. In this study, animals were divided into nine groups and were treated with different combinations of metformin and CPF. Following the 28 days of CPF and metformin administration, brain tissues were separated. The levels of inflammatory biomarkers such as tumor necrosis factor alpha (TNFα) and interleukin 1β (IL-1β), as well as the expression of 5HT1 and 5HT2 genes, were analyzed. Moreover, the levels of malondialdehyde (MDA), reactive oxygen species (ROS), and the ADP/ATP ratio, in addition to the activity of acetylcholinesterase (AChE) and superoxide dismutase (SOD), were tested through in vitro experiments. This study demonstrated the potential role of metformin in alleviating the mentioned biomarkers, which can be altered negatively as a result of CPF toxicity. Moreover, metformin showed protective potential in modulating inflammation, as well as oxidative stress, the expression of genes, and histological analysis, in a concentration-dependent manner.

Ameliorative Effects of Humulus japonicus Extract and Polysaccharide-Rich Extract of Phragmites rhizoma in Rats with Gastrointestinal Dysfunctions Induced by Water Avoidance Stress

Chronic stress can cause the gastrointestinal disorders characterized by an altered bowel movement and abdominal pain. Studies have shown that Humulus japonicus extract (HJE) has anti-inflammatory and antidiarrheal effects, and Phragmites rhizoma extract (PEP) has antioxidative and antistress effects. The present study aimed to investigate the possible effects of HJE and PEP in rat models with stress-induced gastrointestinal dysfunctions. The rats were exposed to water avoidance stress (WAS, 1 h/day) for 10 days to induce gastrointestinal disorders. We found that WAS significantly increased fecal pellet output during 1 h stress, gastric emptying, colonic contractility, and permeability compared to the normal rats. Pretreatment with HJE and PEP (0.25 and 0.5 mL/kg, both administered separately) improved the increased gastric emptying and colonic contractility induced by electrical field stimulation, acetylcholine, and serotonin and also alleviated the increased colonic permeability. HJE and PEP also increased the claudin-1 and occludin expressions, reduced by WAS. WAS increased the concentration of TNF-α and TBARS and reduced FRAP. HJE and PEP recovered these effects. HJE and PEP improved the gastrointestinal disorders induced by WAS by upregulating the tight junction protein, possibly acting on cholinergic and serotonergic receptors to abolish the colonic hypercontractility and hyperpermeability and degradation of inflammatory cytokines via an antioxidant effect.

Research progress regarding potential effects of traditional Chinese medicine on postoperative intestinal obstruction

OBJECTIVES

Postoperative intestinal obstruction is a common postoperative complication with typical symptoms of abdominal pain, vomiting, abdominal distension and constipation. The principal aim of this paper is to provide a full-scale review on the categories and characteristics of postoperative intestinal obstruction, pathophysiology, effects and detailed mechanisms of compounds and monomers from traditional Chinese medicine for treating postoperative intestinal obstruction. Moreover, the possible development and perspectives for future research are also analyzed.

METHODS

Literature regarding postoperative intestinal obstruction as well as the anti-pio effect of aqueous extracts and monomers from traditional Chinese medicine in the last 20 years was summarized.

KEY FINDINGS

To date, approximately 30 compounds and 25 monomers isolated from traditional Chinese medicine including terpenes, alkaloids, polysaccharides, flavonoids, phenylpropanoids and quinones, have exerted significant antipio effect. This paper reviews the effective doses, models, detailed mechanisms, and composition of these traditional Chinese medicine compounds, as well as the structure of these monomers. Moreover, challenges existed in the current investigation and further perspectives were discussed as well, hoping to provide a reference for future clinical treatment of postoperative intestinal obstruction and the development of new drugs.

CONCLUSIONS

Above all, the convincing evidence from modern pharmacology studies powerfully supported the great potential of traditional Chinese medicine in the management of postoperative intestinal obstruction. Regrettably, less attention was currently paid on the mechanisms of traditional Chinese medicine compounds and monomers with antipio effect. Consequently, future study should focus on monomer-mechanism and structure-function relationship.

Camelina sativa Methanolic and Ethanolic Extract Potential in Alleviating Oxidative Stress, Memory Deficits, and Affective Impairments in Stress Exposure-Based Irritable Bowel Syndrome Mouse Models

Camelina sativa is mainly used as an oilseed crop; its edible oil is being also used as a traditional home remedy for the treatment of ulcers, wounds, and eye inflammations, due to the antioxidant activities. In the present study, the chemically characterized alcoholic extracts of Camelina sativa var. Madalina defatted seeds (5 g/kg body weight p.o., suspended in CMC-Na 0.1%) were administered to stress-induced animal models of irritable bowel syndrome (based on combinations of contention stress and multifactorial stress and maternal stress) and evaluated for the behavioural (short-term memory by the Y maze test, the anxious behaviour using the elevated plus maze test, and the antidepressant effect using the forced swimming test) and brain and bowel tissue oxidative status (superoxide dismutase and glutathione peroxidase enzymes activities and malondialdehyde and total soluble protein levels) improving effects. According to the chemical characterization, the extracts were rich in sinapine, glucosinolates, and flavonol glycosides. Moreover, this study showed the beneficial effects of Camelina sativa seed methanolic and ethanolic extracts on the behaviour and brain and bowel tissues oxidative stress status of stress exposure-based IBS mouse models. Despite the slight differences in the chemical composition of the methanolic and ethanolic extracts, the results suggested that the Camelina sativa extracts could reverse the short-term memory impairments caused by stress exposure and also could decrease the intensity and frequency of the anxiety and depressive-like behaviours observed in the stress-exposed animal models of IBS. Furthermore, the Camelina sativa extracts showed a significant effect on the oxidative stress markers in the brain and bowel tissues of the studied animal model by decreasing the superoxide dismutase activity and increasing the glutathione peroxidase activity. However, the results suggested that the extracts could also increase lipid peroxidation in bowel tissues. In this way, this study provides additional evidence that the administration of Camelina sativa seed alcoholic extracts could improve cognitive performances and mood and exhibit the antioxidant capacity in both the brain and bowel tissues.

Behavioral and Oxidative Stress Changes in Mice Subjected to Combinations of Multiple Stressors Relevant to Irritable Bowel Syndrome

Background and Objectives: Irritable bowel syndrome (IBS) is a well-known functional gastrointestinal (GI) disorder exhibiting a wide range of symptoms due to individual variability and multifactorial etiology. Stress exposure is a major risk factor for the development of IBS. Here, we investigate the differential effects of psychological stress exposures on behavior and oxidative status in mice by using increasingly complex combinations of etiologic IBS-relevant stressors (maternal separation and chronic unpredictable mild stress combinations). Materials and Methods: Mice were subjected to three different combinations of psychological stress factors and subsequent behavioral cognitive and affective parameters and oxidative status markers (superoxide dismutase and glutathione peroxidase antioxidant activity and malondialdehyde level) in the brain and bowel tissues of the animals were analyzed. Results: GI transit modifications reflected by decreased fecal output, cognitive and affective behavioral deficits were observed in all stress exposed groups, but were more evident for the more complex combinations of stressors. Behavioral deficits were accompanied by mild oxidative stress occurring in the bowel and to a greater extent in brain tissue. Conclusions: The presented data depict the effect of various associations in mimicking IBS symptoms and comorbidities and suggest that an all-inclusive combination of early and adult-life psychological stressors is more effective in IBS symptoms modulation. Oxidative stress in both brain and bowel, suggestive for brain-gut molecular connectivity, may play an important role in IBS mechanistic.

The trace aminergic system: a gender-sensitive therapeutic target for IBS?

Due to a lack of specific or sensitive biomarkers, drug discovery advances have been limited for individuals suffering from irritable bowel syndrome (IBS). While current therapies provide symptomatic relief, inflammation itself is relatively neglected, despite the presence of chronic immune activation and innate immune system dysfunction. Moreover, considering the microgenderome concept, gender is a significant aetiological risk factor. We believe that we have pinpointed a "missing link" that connects gender, dysbiosis, diet, and inflammation in the context of IBS, which may be manipulated as therapeutic target. The trace aminergic system is conveniently positioned at the interface of the gut microbiome, dietary nutrients and by-products, and mucosal immunity. Almost all leukocyte populations express trace amine associated receptors and significant amounts of trace amines originate from both food and the gut microbiota. Additionally, although IBS-specific data are sparse, existing data supports an interpretation in favour of a gender dependence in trace aminergic signalling. As such, trace aminergic signalling may be altered by fluctuations of especially female reproductive hormones. Utilizing a multidisciplinary approach, this review discusses potential mechanisms of actions, which include hyperreactivity of the immune system and aberrant serotonin signalling, and links outcomes to the symptomology clinically prevalent in IBS. Taken together, it is feasible that the additional level of regulation by the trace aminergic system in IBS has been overlooked, until now. As such, we suggest that components of the trace aminergic system be considered targets for future therapeutic action, with the specific focus of reducing oxidative stress and inflammation.

Irritable Bowel Syndrome and Neurological Deficiencies: Is There A Relationship? The Possible Relevance of the Oxidative Stress Status

Background: Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders, exhibiting complex and controversial pathological features. Both oxidative stress and inflammation-related reactive oxygen species production may be involved in IBS pathological development. Thus, we focused on several aspects regarding the causes of oxidative stress occurrence in IBS. Additionally, in the molecular context of oxidative changes, we tried to discuss these possible neurological implications in IBS. Methods: The literature search included the main available databases (e.g., ScienceDirect, Pubmed/Medline, Embase, and Google Scholar). Articles in the English language were taken into consideration. Our screening was conducted based on several words such as “irritable bowel syndrome”, “gut brain axis”, “oxidative stress”, “neuroendocrine”, and combinations. Results: While no consistent evidence suggests clear pathway mechanisms, it seems that the inflammatory response may also be relevant in IBS. The mild implication of oxidative stress in IBS has been described through clinical studies and some animal models, revealing changes in the main markers such as antioxidant status and peroxidation markers. Moreover, it seems that the neurological structures involved in the brain-gut axis may be affected in IBS rather than the local gut tissue and functionality. Due to a gut-brain axis bidirectional communication error, a correlation between neurological impairment, emotional over-responsiveness, mild inflammatory patterns, and oxidative stress can be suggested. Conclusions: Therefore, there is a possible correlation between neurological impairment, emotional over-responsiveness, mild inflammatory patterns, and oxidative stress that are not followed by tissue destruction in IBS patients. Moreover, it is not yet clear whether oxidative stress, inflammation, or neurological impairments are key determinants or in which way these three interact in IBS pathology. However, the conditions in which oxidative imbalances occur may be an interesting research lead in order to find possible explanations for IBS development.

Preliminary Biochemical Description of Brain Oxidative Stress Status in Irritable Bowel Syndrome Contention-Stress Rat Model

Background and objectives: Oxidative stress and inflammation have been implicated in the etiology of irritable bowel syndrome (IBS), a common gastrointestinal functional disease. This study aimed to further characterize the contention-stress rat model by exploring a possible correlation between oxidative stress markers measured in brain tissues with behavioral components of the aforementioned model. Thus, it is hereby proposed a possible IBS animal model relevant to pharmacological and complementary medicine studies. Materials and Methods: Wild-type male Wistar rats (n = 5/group) were chronically exposed to 6-hour/day contention, consisting of isolating the animals in small, vital space-granting plastic devices, for seven consecutive days. Following contention exposure, temporal lobes were extracted and subjected to biochemical analyses to assess oxidative stress-status parameters. Results: Our results show increased brain oxidative stress in contention-stress rat model: decreased superoxide dismutase and glutathione peroxidase activities and increased malondialdehyde production in the IBS group, as compared to the control group. Furthermore, the biochemical ratios which are used to evaluate the effectiveness of an antioxidant system on oxidative stress could be described in this model. Conclusions: The correlations between the behavioral patterns and biochemical oxidative stress features could suggest that this may be a complex model, which can successfully mimic IBS symptomatology further providing evidence of a strong connection between the digestive system, enteric nervous system, and the central nervous system.

The impact of topical Saint John's Wort (Hypericum perforatum) treatment on tissue tumor necrosis factor-alpha levels in plaque-type psoriasis: A pilot study

Context:

Psoriasis is an inflammatory disorder, formed by inappropriate interaction of T lymphocytes with keratinocytes, and consequent eruption of immune responses. High concentrations of tumor necrosis factor-alpha (TNFα) are found in the skin lesions and plasma of patients with psoriasis. Hypericum perforatum, a phytomedicine that has both anti-inflammatory and antiproliferative properties, has been recently reported to be clinically helpful for improvement of psoriatic lesions.

Aims:

The aim of the present study was to investigate the effects of topical H. perforatum on TNFα levels in psoriatic lesions for possible identification of the mechanism by which Hypericum reduces inflammation and modulates the disease in patients with plaque-type psoriasis.

Settings and Design:

A double-blind, placebo-controlled, pilot study with intraindividual comparison was conducted on twenty patients with mild to moderate plaque-type psoriasis.

Subjects and Methods:

TNFα levels in tissue samples were measured with immunohistochemistry method. Moreover, Psoriasis Area Severity Index (PASI) scores and histological and clinical changes were investigated after topical application of Hypericum extract.

Statistical Analysis Used:

The Wilcoxon signed-rank test was used to evaluate the possible differences between the drug and placebo group.

Results:

TNFα concentrations in dermis (p= 0.025), endothelial cells (p=0.033), and dendrite cells (p=0.014) were significantly reduced in lesions treated with drug and the reduction observed in epidermis was superior to placebo (p=0.046). Results of PASI scores showed that erythema, scaling, and thickness were significantly lower where the ointment had been applied compared to application of placebo (p=0.014, p=0.004, p=0.003, respectively). Moreover, significant improvement in clinical and histological features of treated lesions in comparison with untreated lesions was observed (p < 0.05).

Conclusions:

H. perforatum ointment can help decrease PASI scores and TNFα levels in psoriatic tissue. Its efficacy is probably related to its effect on lowering cytokines including TNFα.

Antioxidant Capacity and Behavioral Relevance of a Polyphenolic Extract of Chrysanthellum americanum in a Rat Model of Irritable Bowel Syndrome

Chrysanthellum americanum L. (Vatke) is a medicinal plant from the Compositae family used in west-African traditional medicine, known for its flavonoid and saponin richness and for its strong antioxidant potential. In the present study, we assessed the effects of Chrysanthellum americanum polyphenolic extract in the psychological stress-induced rat model of irritable bowel syndrome (IBS), a chronic functional digestive tract disorder marked by immune and inflammatory-related disturbances of central nervous and peripheral intestinal systems, which is often associated with mood disorders including depression and anxiety. Consequently, memory impairment, anxiety and depression behavioral indicators, and cerebral oxidative stress biomarker dynamics were evaluated in a multifactorial heterotypic stress-exposed IBS rats after 6-day gavage with polyphenolic C. americanum extract (100 mg/kg body weight). Y-maze, elevated plus maze, and forced swimming tests were used for assessing behavioral responses. Administration of the extract exhibited significant anxiolytic and antidepressant-like effects coupled with significantly increased temporal lobe antioxidant enzyme specific activity (superoxide dismutase and glutathione peroxidase) and decreased malondialdehyde levels, a well-known lipid peroxidation marker. Furthermore, linear regression statistical analyses showed significant correlations between the oxidative stress parameters and behavioral tests. In conclusion, our results suggest that the administration of Chrysanthellum americanum polyphenolic extract could ameliorate mood and cognitive disturbances related to stress-induced in an IBS rat model. This could be also related to cerebral oxidative stress status attenuation.

Describing some behavioural animal models of anxiety and their mechanistics with special reference to oxidative stress and oxytocin relevance

It is now generally accepted that animal studies are playing an important role in the understanding of anxiety disorders, since they contribute to the current knowledge regarding the mechanisms and possible therapeutic approaches in anxiety. In the present review we will detail some essential aspects of behavioral animal models of anxiety related to social defeat paradigm, elevated plus maze, elevated zero or T maze, light/dark box, social interaction test or tests based on predator models, considering the latest theories and methodological approaches in this area of research, as well as our previous studies focusing on anxiety manifestations in a variety of species including rats, zebrafish, dogs and pigs. Moreover, in this context, we will focus on the recent theories concerning oxidative stress, as well as importance of oxytocin administration (especially the intranasal route). This could be important considering that these two factors are currently being investigated as possible mechanisms (oxidative stress status) and related therapeutic target (both intranasal oxytocin and antioxidants) in the pathology of the anxiety disorders.

The effect of hypericum perforatum on kidney ischemia/reperfusion damage

It has been revealed in recent studies that Hypericum Perforatum (HP) is influential on cancer, inflammatory diseases, bacterial and viral diseases, and has neuroprotective and antioxidant properties. In this study, we investigated the effect of HP, which is known to have antioxidant and anti-inflammatory effects, on kidney I/R damage. Male Sprague–Dawley rats were divided into three groups, and each of the groups had eight rats: The Control Group; the Ischemia/Reperfusion (I/R) Group; and the IR + HP Group which was treated with 50 mg/kg of HP. The right kidneys of the rats were removed, and the left kidney developed ischemia during the 45th min, and reperfusion occurred in the following 3rd h. The histopathological findings and also the level of Malondialdehyde (MDA), Glutathione (GSH) and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX) enzyme activations in the renal tissues were measured. Blood Urea Nitrogen (BUN), Creatinin (Cre) from serum samples were determined. The levels of BUN, Cre, and kidney tissue MDA increased at a significant level, and the SOD, CAT, and GSH-PX enzyme activity decreased at a significant level in the I/R group, compared with the Control Group (p < 0.05). In the I/R + HP group, the levels of MDA decreased at a significant level compared to the I/R group, while the SOD, CAT, and GSH-PX activity increased (p < 0.05). In histopathological examinations, it was observed that the tubular dilatation and epithelial desquamation regressed in the IR + HP Group when compared with the I/R Group. It has been shown with the histological and biochemical results in this study that HP is protective against acute renal I/R.

Ameliorative effects of atractylodin on intestinal inflammation and co-occurring dysmotility in both constipation and diarrhea prominent rats

Intestinal disorders often co-occur with inflammation and dysmotility. However, drugs which simultaneously improve intestinal inflammation and co-occurring dysmotility are rarely reported. Atractylodin, a widely used herbal medicine, is used to treat digestive disorders. The present study was designed to characterize the effects of atractylodin on amelioration of both jejunal inflammation and the co-occurring dysmotility in both constipation-prominent (CP) and diarrhea-prominent (DP) rats. The results indicated that atractylodin reduced proinflammatory cytokines TNF-α, IL-1β, and IL-6 in the plasma and inhibited the expression of inflammatory mediators iNOS and NF-kappa B in jejunal segments in both CP and DP rats. The results indicated that atractylodin exerted stimulatory effects and inhibitory effects on the contractility of jejunal segments isolated from CP and DP rats respectively, showing a contractile-state-dependent regulation. Atractylodin-induced contractile-state-dependent regulation was also observed by using rat jejunal segments in low and high contractile states respectively (5 pairs of low/high contractile states). Atractylodin up-regulated the decreased phosphorylation of 20 kDa myosin light chain, protein contents of myosin light chain kinase (MLCK), and MLCK mRNA expression in jejunal segments of CP rats and down-regulated those increased parameters in DP rats. Taken together, atractylodin alleviated rat jejunal inflammation and exerted contractile-state-dependent regulation on the contractility of jejunal segments isolated from CP and DP rats respectively, suggesting the potential clinical implication for ameliorating intestinal inflammation and co-occurring dysmotility.

Serotonin and histamine mediate gastroprotective effect of fluoxetine against experimentally-induced ulcers in rats

Research in the treatment of gastric ulcer has involved the investigation of new alternatives, such as anti-depressant drugs. The present study was designed to investigate the gastroprotective effects of fluoxetine against indomethacin and alcohol induced gastric ulcers in rats and the potential mechanisms of that effect. Fluoxetine (20 mg/kg) was administered IP for 14 days. For comparative purposes, other rats were treated with ranitidine (30 mg/kg). Thereafter, after 24 h of fasting, INDO (100 mg/kg) or absolute alcohol (5 ml/kg) was administered to all rats (saline was administered to naïve controls) and rats in each group were sacrificed 5 h (for INDO rats) or 1 h (for alcohol rats) later. Macroscopic examination revealed that both fluoxetine and ranitidine decreased ulcer scores in variable ratios, which was supported by microscopic histopathological examination. Biochemical analysis of fluoxetine- or ranitidine-pre-treated host tissues demonstrated reductions in tumor necrosis factor (TNF)-α and myeloperoxidase (MPO) levels and concomitant increases in gastric pH, nitric oxide (NO) and reduced glutathione (GSH) contents. Fluoxetine, more than ranitidine, also resulted in serotonin and histamine levels nearest to control values. Moreover, immuno-histochemical analysis showed that fluoxetine markedly enhanced expression of cyclo-oxygenases COX-1 and COX-2 in both models; in comparison, ranitidine did not affect COX-1 expression in either ulcer model but caused moderate increases in COX-2 expression in INDO-induced hosts and high expression in alcohol-induced hosts. The results here indicated fluoxetine exhibited better gastroprotective effects than ranitidine and this could be due to anti-secretory, anti-oxidant, anti-inflammatory and anti-histaminic effects of the drug, as well as a stabilization of gastric serotonin levels.

Restraint stress induces and exacerbates intestinal inflammation in interleukin-10 deficient mice

AIM: To investigate the effects of restraint stress on chronic colitis in interleukin (IL)-10 deficient (IL-10^-/-) mice.

METHODS: The first experiment compared the effect of restraint stress on the development of intestinal inflammation in wild-type and IL-10^-/- mice. Both wild-type and IL-10^-/- mice were physically restrained in a well-ventilated, 50 cm³ conical polypropylene tube for 2 h per day for three consecutive days. The second experiment was performed to assess the effect of restraint stress on exacerbation of colitis induced by piroxicam in IL-10^-/- mice. The IL-10^-/- mice were exposed to restraint stress for 2 h per day for 3 consecutive days, and then treated with piroxicam for 4 d at a dose of 200 ppm administered in the rodent chow.

RESULTS: In the first experiment, none of the wild-type mice with or without restraint stress showed clinical and histopathological abnormality in the gut. However, IL-10^-/- mice exposed to restraint stress exhibited histologically significant intestinal inflammation as compared to those without restraint stress. In the second experiment, restraint stress significantly reduced body weight and increased the severity of intestinal inflammation assessed by histopathologic grading in IL-10^-/- mice. Colonic IL12p40 mRNA expression was strongly increased in mice exposed to restraint stress.

CONCLUSION: This novel animal model could be useful in future study of psychological stress in the pathogenesis of inflammatory bowel disease.

Capsaicin alleviates abnormal intestinal motility through regulation of enteric motor neurons and MLCK activity: Relevance to intestinal motility disorders

SCOPE

Capsaicin is an active component of chili peppers, having diverse effects. However, the effects of capsaicin on intestinal motility are still controversial. The present study aimed to investigate the effects of capsaicin on intestinal motility disorder and uncover related mechanisms.

MATERIALS AND RESULTS

A rat model with intestinal motility disorder was established in vitro through adding different stimuli into tissue bath; in vivo using constipation and diarrhea model, respectively. Capsaicin exerted dual effects on intestinal motility, i.e. the relaxation and contraction of jejunum induced by corresponding stimulus were, respectively, regulated to be normal contraction by capsaicin. The mechanisms underlined capsaicin-induced dual effects were investigated using Western blotting, qRT-PCR, and whole-cell patch clamp, respectively. Results showed that cholinergic excitatory nerves, adrenergic nerves, and neurons containing nitric oxide synthase, which are the main muscle motor neurons in enteric nervous system (ENS), are involved in capsaicin-induced dual effects. The competition for regulation of Ca(2+) influx by capsaicin induced the interaction with components of the ENS. Capsaicin significantly increased myosin light chain kinase (MLCK) expression and myosin phosphorylation extent in jejunal segments of constipation-prominent rats and significantly decreased MLCK expression and myosin phosphorylation extent in jejunal segments of diarrhea-prominent rats.

CONCLUSION

In summary, capsaicin alleviates abnormal intestinal motility through regulating enteric motor neurons and MLCK activity, which is beneficial for the treatment of gastrointestinal motility disorders.

Effectiveness of probiotics in irritable bowel syndrome: Updated systematic review with meta-analysis

AIM: To investigate the efficacy of probiotics in irritable bowel syndrome (IBS) patients.

METHODS: PubMed, Cochrane library, Scopus, Google Scholar, and Clinicaltrial.gov databases were searched for literature published between September 2007 and December 2013. The applied Mesh terms were “probiotics,”“irritable bowel syndrome,” and “irritable bowel syndrome treatment.” The collected data contained24 clinical trials, of which 15 were eligible for meta-analysis and nine were reviewed systematically. All studies were randomized placebo-controlled trials in patients with IBS that investigated the efficacy of probiotics in IBS improvement. The Jadad score was used to assess the methodological quality of trials. The quality scale ranges from 0 to 5 points, with a score ≤ 2 indicating a low quality report, and a score of ≥ 3 indicating a high quality report. Relative risk (RR), standardized effect size, and 95%CI were calculated using the DerSimonian-Laird method. The Cochran Q test was used to test heterogeneity with P < 0.05. Funnel plots were constructed and Egger’s and Begg-Mazumdar tests were performed to assess publication bias.

RESULTS: A total of 1793 patients were included in the meta-analysis. The RR of responders to therapies based on abdominal pain score in IBS patients for two included trials comparing probiotics to placebo was 1.96 (95%CI: 1.14-3.36; P = 0.01). RR of responders to therapies based on a global symptom score in IBS patients for two included trials comparing probiotics with placebo was 2.43 (95%CI: 1.13-5.21; P = 0.02). For adequate improvement of general symptoms in IBS patients, the RR of seven included trials (six studies) comparing probiotics with placebo was 2.14 (95%CI: 1.08-4.26; P = 0.03). Distension, bloating, and flatulence were evaluated using an IBS severity scoring system in three trials (two studies) to compare the effect of probiotic therapy in IBS patients with placebo, the standardized effect size of mean differences for probiotics therapy was -2.57 (95%CI: -13.05--7.92).

CONCLUSION: Probiotics reduce pain and symptom severity scores. The results demonstrate the beneficial effects of probiotics in IBS patients in comparison with placebo.

Aromatic Medicinal Plants from Tajikistan (Central Asia)

Tajikistan is a small country located in Central Asia. The mostly mountainous terrain with a continental, subtropical, and semiarid climate, is characterized by diverse flora. Many people in Tajikistan rely on medicinal plants as their traditional form of medicine to prevent and cure health disorders. Aromatic medicinal plants, in particular, have played an important role for the local people. In this review, we present a summary of the uses of 18 aromatic medicinal plants from Tajikistan and their compositions of secondary metabolites.

The safety of novel drugs used to treat irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) is a chronic gastrointestinal (GI) disorder with a high prevalence. Besides efficacy, the safety of each drugs used to treat GI disorders is an important issue in the drug development process.

AREAS COVERED

This article reviews all Phase I to IV clinical trials or case reports with results related to the safety of novel GI drugs. The drugs are currently approved or under evaluation for approval.

EXPERT OPINION

Most of the reported adverse events were related to the GI tract with mild-to-moderate severity. Diarrhea was significantly higher versus placebo following use of linaclotide and renzapride, similar to that of constipation with ramosetron. Lubiprostone, linaclotide and rifaximin with low systemic bioavailability have less adverse events and exert more advantageous results. Asimadoline acts peripherally on κ-opioid receptors and is not associated with CNS side effects. As lubiprostone and linaclotide cause dose-dependent adverse events, starting the treatment with the lowest effective doses is advised. Ramosetron is under evaluation for diarrhea-predominant IBS due to its acceptable safety and tolerability, besides its efficacy. Rifaximin, asimadoline and renzapride are still in need of more long-term studies regarding their safety.

Anti-aging effects of some selected Iranian folk medicinal herbs-biochemical evidences

OBJECTIVE(S)

In the current study, the effects of selected folk medicinal herbs were evaluated in D-galactose-induced aging in male mice.

MATERIALS AND METHODS

Male BALB/c mice were randomly divided into 12 groups composing sham, control, and treated groups. Aging was induced by administration of D-galactose (500 mg/kg/day for 6 weeks). A positive control group was assigned that received vitamin E (200 mg/kg/day). The extract of herbs was prepared, lyophilized, and used in this study. The herbs were administered by gavage for 4 weeks to D-galactose-aged animals at the selected doses (mg/kg/day) as follows: Zingiber officinale (250), Glycyrrhiza glabra (150), Rosmarinus officinalis (300), Peganum harmala (50), Aloe vera (150), Satureja hortensis (200), Teucrium scordium (200), Hypericum perforatum (135) and Silybum marianum (150). One group of animals was assigned as sham and not given D-galactose.

RESULTS

At the end of treatment, pro-inflammatory markers including tumor necrosis factor-α (TNF-α), interlukine-1β (IL-β), interlukine-6 (IL-6), NF-kappaB (NF-κb), total antioxidant power (TAP), thiobarbituric acid reactive substances (TBARS) as lipid peroxidation (LPO) marker and male sex hormones i.e. testosterone and dehydroepiandrosterone-sulfate (DHEA-S) were measured in the blood.

CONCLUSION

These data for the first time indicate significant anti-aging potential of examined herbs. RESULTS showed that D-galactose induces a significant oxidative stress and promotes proinflammatory cascade of aging while all herbs more or less recovered these changes. Among 9 herbal extracts, Silybum marianum showed the best effect in restoring aging changes.

The role of oxidants and reactive nitrogen species in irritable bowel syndrome: a potential etiological explanation

Background

The aim of this study was to evaluate the plasma concentrations of malondialdehyde (MDA) and nitric oxide (NO) and the plasma activities of oxidant and antioxidant enzymes in patients with IBS.

Material/Methods

A total of 36 patients with IBS were included in the study. Thirty-five healthy subjects were selected to form the control group. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), xanthine oxidase (XO), adenosine deaminase (AD) activities, and malondialdehyde (MDA) and nitric oxide (NO) concentrations were studied in the serum samples of all patients and controls.

Results

Plasma XO and AD activities, and MDA and NO concentrations were significantly higher in IBS patients than in controls. The SOD, CAT, and GSH-Px activities in the serum of patients with IBS were significantly lower than that of controls.

Conclusions

These results suggest that lipid peroxidation and alterations in the oxidant-antioxidant enzymatic system may play a role in the pathogenesis of IBS. Increased lipid peroxidation in IBS may be related to an increase in NO level and XO activity and a decrease in antioxidant enzymes activities. In addition, increased AD activity may have a role in immunological changes of IBS patients.

Benefit of Aloe vera and Matricaria recutita mixture in rat irritable bowel syndrome: Combination of antioxidant and spasmolytic effects

OBJECTIVE: To evaluate the beneficial effects of a mixture of Aloe vera (AV) and Matricaria recutita (German chamomile, GC) in an experimental model of irritable bowel syndrome (IBS). METHODS: IBS was induced by a 5-day restraint stress in rats including the groups of control (water), GC (300 mg/kg), loperamide (10 mg/kg), mixed AV and GC (50: 50 at doses of 150, 300 or 450 mg/kg assigned as Mix-150, Mix-300 and Mix-450, respectively) and the sham group which did not receive any restraint stress and was fed with saline. All medications were administered intragastrically by gavage for 7 days, 2 days as pre-treatment followed by 5 days during induction of IBS every day before restraining. RESULTS: The increased tumor necrosis factor alpha (TNF-α), myeloperoxidase (MPO) activity, and lipid peroxidation (LPO) in colonic cells in the control group were significantly decreased in the treatment groups. GC inhibited only small bowel transit while the AV/GC mixture delayed gastric emptying at the doses of 150 and 300 mg/kg. The AV/GC mixture also reduced colonic transit and small bowel transit at the dose of 150 mg/kg. CONCLUSIONS: The severity of stress-induced IBS was diminished by the AV/GC mixture at all doses used but not dose-dependently, via inhibiting colonic MPO activity and improving oxidative stress status. The effect of the mixture was more effective than GC alone. The present results support effectiveness of the AV and GC combination in IBS.

Characteristics of deslanoside-induced modulation on jejunal contractility

AIM: To characterize the dual effects of deslanoside on the contractility of jejunal smooth muscle.

METHODS: Eight pairs of different low and high contractile states of isolated jejunal smooth muscle fragment (JSMF) were established. Contractile amplitude of JSMF in different low and high contractile states was selected to determine the effects of deslanoside, and Western blotting analysis was performed to measure the effects of deslanoside on myosin phosphorylation of jejunal smooth muscle.

RESULTS: Stimulatory effects on the contractility of JSMF were induced (45.3% ± 4.0% vs 87.0% ± 7.8%, P < 0.01) by deslanoside in 8 low contractile states, and inhibitory effects were induced (180.6% ± 17.8% vs 109.9% ± 10.8%, P < 0.01) on the contractility of JSMF in 8 high contractile states. The effect of deslanoside on the phosphorylation of myosin light chain of JSMF in low (78.1% ± 4.1% vs 96.0% ± 8.1%, P < 0.01) and high contractile state (139.2% ± 8.5% vs 105.5 ± 7.34, P < 0.01) was also bidirectional. Bidirectional regulation (BR) was abolished in the presence of tetrodotoxin. Deslanoside did not affect jejunal contractility pretreated with the Ca²⁺ channel blocker verapamil or in a Ca²⁺-free assay condition. The stimulatory effect of deslanoside on JSMF in a low contractile state (low Ca²⁺ induced) was abolished by atropine. The inhibitory effect of deslanoside on jejunal contractility in a high contractile state (high Ca²⁺ induced) was blocked by phentolamine, propranolol and L-NG-nitro-arginine, respectively.

CONCLUSION: Deslanoside-induced BR is Ca²⁺ dependent and is related to cholinergic and adrenergic systems when JSMF is in low or high contractile states.

Systematic review of modulators of benzodiazepine receptors in irritable bowel syndrome: Is there hope?

Several drugs are used in the treatment of irritable bowel syndrome (IBS) but all have side effects and variable efficacy. Considering the role of the gut-brain axis, immune, neural, and endocrine pathways in the pathogenesis of IBS and possible beneficial effects of benzodiazepines (BZD) in this axis, the present systematic review focuses on the efficacy of BZD receptor modulators in human IBS. For the years 1966 to February 2011, all literature was searched for any articles on the use of BZD receptor modulators and IBS. After thorough evaluation and omission of duplicate data, 10 out of 69 articles were included. BZD receptor modulators can be helpful, especially in the diarrhea-dominant form of IBS, by affecting the inflammatory, neural, and psychologic pathways, however, controversies still exist. Recently, a new BZD receptor modulator, dextofisopam was synthesized and studied in human subjects, but the studies are limited to phase IIb clinical trials. None of the existing trials considered the neuroimmunomodulatory effect of BZDs in IBS, but bearing in mind the concentration-dependent effect of BZDs on cytokines and cell proliferation, future studies using pharmacodynamic and pharmacokinetic approaches are highly recommended.