Antidiarrheal activity of hexane extract of Citrus limon peel in an experimental animal model

UHPLC-MS profiles and antidiarrheal activity of Quercus coccinea münchh. and Quercus robur L. employing in vivo technique

Introduction: Quercus L. genus (Oak) belongs to the family Fagaceae and their galls are used commercially in leather tanning, dyeing, and ink preparation. Several Quercus species were traditionally used to manage wound healing, acute diarrhea, hemorrhoid, and inflammatory diseases. The present study aims to investigate the phenolic content of the 80% aqueous methanol extract (AME) of Q. coccinea and Q. robur leaves as well as to assess their anti-diarrheal activity. Methods: Polyphenolic content of Q. coccinea and Q. robur AME were investigated using UHPLC/MS. The antidiarrheal potential of the obtained extracts was evaluated by conducting a castor oil-induced diarrhea in-vivo model. Result and Discussion: Twenty-five and twenty-six polyphenolic compounds were tentatively identified in Q. coccinea and Q. robur AME, respectively. The identified compounds are related to quercetin, kaempferol, isorhamnetin, and apigenin glycosides and their aglycones. In addition, hydrolyzable tannins, phenolic acid, phenyl propanoides derivatives, and cucurbitacin F were also identified in both species AME of Q. coccinea (250, 500, and 1000 mg/kg) exhibited a significant prolongation in the onset of diarrhea by 17.7 %, 42.6%, and 79.7% respectively while AME of Q. robur at the same doses significantly prolonged the onset of diarrhea by 38.6%, 77.3%, and 2.4 folds respectively as compared to the control. Moreover, the percentage of diarrheal inhibition of Q. coccinea was 23.8%, 28.57%, and 42,86% respectively, and for Q. robur 33.34%, 47.3%, and 57.14% respectively as compared to the control group. Both extracts significantly decreased the volume of intestinal fluid by 27%, 39.78%, and 50.1% for Q. coccinea respectively; and by 38.71%, 51.19%, and 60% for Q. robur respectively as compared to the control group. In addition, AME of Q. coccinea exhibited a peristaltic index of 53.48, 47.18, and 42.28 with significant inhibition of gastrointestinal transit by 18.98%, 28.53%, and 35.95 % respectively; while AME of Q. robur exhibited a peristaltic index of 47.71, 37, and 26.41 with significant inhibition of gastrointestinal transit by 27.72%, 43.89%, and 59.99% respectively as compared with the control group. Notably, Q. robur showed a better antidiarrheal effect in comparison with Q. coccinea and, the highest effect was observed for Q. robur at 1000 mg/kg as it was nonsignificant from the loperamide standard group in all measured parameters.

Neuropharmacological and Antidiarrheal Potentials of Duabanga grandiflora (DC.) Walp. Stem Bark and Prospective Ligand–Receptor Interactions of Its Bioactive Lead Molecules

Duabanga grandiflora (DC.) Walp. is an ethnomedicinally significant plant used to treat various illnesses, but there is little scientific evidence to support its use. This study explored the pharmacological activities of methanol extract of D. grandiflora stem barks (MEDG) through in vivo approaches in Swiss albino mice and a computer-aided molecular approach. The forced swimming test (FST), tail suspension test (TST), elevated plus maze (EPM), and hole board test (HBT) were used to determine anti-depressant and anxiolytic activity in experimental mice. In addition, anti-diarrheal studies were performed using castor oil-induced diarrhea, castor oil-induced enter pooling, and the charcoal-induced gastrointestinal motility test. MEDG showed substantial depletions in the immobility times in both FST and TST after treatment with the MEDG extract, whereas moderate anxiolytic activity was manifested at a higher dose (400 mg/kg) compared with the control. Correspondingly, MEDG extract revealed a significant reduction in wet feces and decreased the small intestinal transit of charcoal meal in castor oil-induced diarrhea and charcoal-induced gastrointestinal motility test. In the computer-aided molecular approaches, vanillin displayed a promising binding score for both anxiolytic and anti-diarrheal activities, while duabanganal C showed a promising score for the anti-depressant activity. The present experimental findings along with a computer-aided model conclude that MEDG could be a possible Phyto therapeutic agent with potential anti-depressant, anxiolytic and anti-diarrheal activity.

Evaluation of the antidiarrheal activity of 80% methanol extract and solvent fractions of the leaf of Bersama abyssinica fresen (Melianthaceae) in mice

Introduction

The use of traditional medicinal plants in the management of diarrhea has long been practiced in Ethiopia. B. abyssinica fresen is one of the plants traditionally used to treat diarrhea whereas an in vivo study had not yet been conducted. Thus, this study aimed to evaluate the antidiarrheal activity of crude extract and solvent fractions of the leaf of B. abyssinica in mice.

Methods

Cold maceration within 80% methanol was used to extract the leaf powder and extract of the leaf was fractionated using n-hexane, chloroform, and distilled water. The in vivo antidiarrheal activity of crude extracts and solvent fractions were tested in experimental models of castor oil-induced diarrhea, enteropooling, and antimotility test. Five groups each with 6 mice were used under the three antidiarrheal models. Positive controls were treated with loperamide 3 mg/kg and atropine 5 mg/kg and 2% tween 80 was used in the treatment of negative controls. The extract and solvent fractions were administered at doses of 100, 200, and 400 mg/kg. Time of onset of diarrhea, number and weight of total and wet feces, the percent reduction in the number of wet feces, weight and volume of intestinal contents, and percent inhibition of intestinal motility were recorded. Data were analyzed using SPSS version 20.

Result

Defecation of castor oil-induced diarrheal or loose stools was inhibited (p < 0.01 to p < 0.001) at 200 mg/kg and 400 mg/kg of crude extract and aqueous fraction. The crude extract and the aqueous fraction at three doses (p < 0.01 to p < 0.001), the chloroform fraction at 200 mg/kg and 400 mg/kg (p < 0.01 to p < 0.001), and the n-hexane fraction at 400 mg/kg (p < 0.05) reduced intraluminal fluid accumulation compared with the negative control. Castor oil-induced intestinal motility was significantly suppressed with the three-doses of aqueous fraction (p < 0.05 to p < 0.001), 200 mg/kg and 400 mg/kg of crude extract (p < 0.05 to p < 0.01), 400 mg/kg of chloroform and n-hexane (p < 0.01 to p < 0.001) compared with negative control.

Conclusion

The crude extract, aqueous, and chloroform fractions of B. abyyssinica leaves have promising anti-diarrheal effects, supporting the plant's traditional use to treat diarrhea.

Mechanisms of antidiarrhoeal activity of methanol leaf extract of Combretum hypopilinum diels (combretaceae): Involvement of opioidergic and (α1 and β)-adrenergic pathways

ETHNOPHARMACOLOGICAL RELEVANCE

The plant Combretum hypopilinum Diels (Combretaceae) is used in traditional medicine for the treatment of diarrhoea and other diseases in Africa. Previously, the antidiarrhoeal activity of its methanol leaf extract was reported. However, the mechanism(s) responsible for this activity is yet to be evaluated.

AIM OF THE STUDY

This study aimed to elucidate the possible mechanism(s) of antidiarrhoeal activity of methanol leaf extract of Combretum hypopilinum (MECH) in mice.

MATERIALS AND METHODS

Phytochemical screening and acute toxicity study were conducted according to standard methods. Adult mice were orally (p.o) administered distilled water (10 ml/kg), MECH (1000 mg/kg) and loperamide (5 mg/kg). The probable mechanisms of antidiarrhoeal activity of MECH were investigated following pretreatment with naloxone (2 mg/kg, subcutaneously), prazosin (1 mg/kg, s.c), yohimbine (2 mg/kg, intraperitoneally), propranolol (1 mg/kg, i.p), pilocarpine (1 mg/kg, s.c) and isosorbide dinitrate (150 mg/kg, p.o) 30 min before administration of MECH (1000 mg/kg). The mice were then subjected to castor oil-induced intestinal motility test.

RESULTS

The oral median lethal dose (LD₅₀) of MECH was found to be higher than 5000 mg/kg. There were significant (p < 0.05) decrease in the charcoal movement in the mice treated with the MECH (1000 mg/kg) and loperamide (5 mg/kg). The pretreatment of the mice with naloxone, prazosin and propranolol each significantly (p<0.05) reversed the antidiarrhoeal activity produced by MECH.

CONCLUSION

The results obtained in this study suggest the probable involvement of opioidergic and (α₁ and β)-adrenergic systems in the antidiarrhoeal activity of the methanol leaf extract of Combretum hypopilinum.

Phenolic composition, antioxidant potential and health benefits of citrus peel

Citrus peel (CP) forms around 40-50% of the total fruit mass but is generally thought to be a waste. However, it is a substantial source of naturally occurring health enhancing compounds, particularly phenolic compounds and carotenoids. Phenolic compounds in CP mainly comprise phenolic acids (primarily caffeic, p-coumaric, ferulic and sinapic acid), flavanones (generally naringin and hesperidin) and polymethoxylated flavones (notably nobiletin and tangeretin). It has also been noted that CP's contain more amounts of these compounds than corresponding edible parts of the fruits. Phenolic compounds present in CP act as antioxidants (by either donation of protons or electrons) and protect cells against free radical damage as well as help in reducing the risk of many chronic diseases. Owing to the more abundance of polyphenols in CP's, their antioxidant activity is also higher than other edible fruit parts. Therefore, peels from citrus fruits can be used as sources of functional compounds and preservatives for the development of newer food products, that are not only safe but also have health-promoting activities. The present review provides in-depth knowledge about the phenolic composition, antioxidant potential and health benefits of CP.

Ricin: An Ancient Story for a Timeless Plant Toxin

The castor plant (Ricinus communis L.) has been known since time immemorial in traditional medicine in the pharmacopeia of Mediterranean and eastern ancient cultures. Moreover, it is still used in folk medicine worldwide. Castor bean has been mainly recommended as anti-inflammatory, anthelmintic, anti-bacterial, laxative, abortifacient, for wounds, ulcers, and many other indications. Many cases of human intoxication occurred accidentally or voluntarily with the ingestion of castor seeds or derivatives. Ricinus toxicity depends on several molecules, among them the most important is ricin, a protein belonging to the family of ribosome-inactivating proteins. Ricin is the most studied of this category of proteins and it is also known to the general public, having been used for several biocrimes. This manuscript intends to give the reader an overview of ricin, focusing on the historical path to the current knowledge on this protein. The main steps of ricin research are here reported, with particular regard to its enzymatic activity, structure, and cytotoxicity. Moreover, we discuss ricin toxicity for animals and humans, as well as the relation between bioterrorism and ricin and its impact on environmental toxicity. Ricin has also been used to develop immunotoxins for the elimination of unwanted cells, mainly cancer cells; some of these immunoconjugates gave promising results in clinical trials but also showed critical limitation.

Antidiarrheal activity of α-terpineol in mice

Diarrhea is one of the leading causes of infant death in the world accounting for high child mortality rate. It is also present in different pathophysiologies related to several etiological agents. The aim of this study is to investigate the antidiarrheal effect of α -Terpineol (α-TPN) in different diarrhea models in rodents. The antidiarrheal effect of α-TPN in the treatment of acute diarrhea and enteropooling induced by castor oil or PGE₂ in Swiss mice pretreated orally with saline (NaCl 0.9%), Loperamide (5 mg/kg) and α-TPN (6.25, 12.5, 25 and 50 mg/kg) was analyzed. Additionally, parameters of severity, total weight of faeces and post-treatment for 4 h were evaluated. Modulation of the opioid and cholinergic pathways was performed and intestinal transit model using activated charcoal as marker was also used. The effect of α-TPN on secretory diarrhea was investigated using the model of fluid secretion in intestinal loops isolated from cholera toxin-treated mice. α-TPN showed antidiarrheal effect (*p < 0.05), reducing the total stool amount (*55%, *48%, *44%, *24%) and diarrheal (*47%, *66%; *56%, 10%) respectively for the doses tested. All doses investigated in the enteropooling test presented significant changes (*46%, *78%, *66%, *41% respectively) in relation to the control. α-TPN through the muscarinic pathway reduced the gastrointestinal transit (*31%), besides inhibiting PGE₂-induced diarrhea (*39%). α-TPN also reduced fluid formation and loss of Cl^- ions, by interacting directly with GM1 receptors and cholera toxin, thus increasing the uptake of intestinal fluids. The results suggest an anti-diarrheal activity of α-TPN due to its anticholinergic action, ability to block PGE₂ and GM1 receptors and interaction with cholera toxin in secretory diarrhea, making it a promising candidate drug for the treatment of diarrheal diseases.