A Das, R Rohini, A Hema
antidiarrhea, phytochemical, rhizophora mucronata
A Das, R Rohini, A Hema. Evaluation of Anti-diarrhea activity of Rhizophora mucronata bark extracts. The Internet Journal of Alternative Medicine. 2008 Volume 7 Number 1.
Diarrhea is characterized by frequent, watery bowel movements, often accompanied by stomach cramps, abdominal pain and gas. Diarrhea may be of various colors and contain mucous, blood or pus. According to World Health Organization, Diarrhea occurs worldwide and causes 4 % of all deaths and 5 % of health loss due to disability. It is most commonly caused by gastrointestinal infections, which kill around 2.2 million people globally each year. It is most commonly caused by gastrointestinal infections, which kill around 2.2 million people globally each year, mostly children in developing countries . Enteric pathogens in Thailand have developed resistance to virtually all antibiotics routinely used in the treatment of diarrhea, as well as the newer fluoroquinolone and macrolide classes of drugs . An urge to develop new and better drugs is always emerging. Nature has provided infinite folk remedies for various ailments. In both China and India herbs like Chebula, Swertia
Atropine used as standard antidiarrhoeal drug, Castor oil (laxative agent), activated charcoal, Gum Acacia, acetylcholine and histamine were of pharmacological grade. All other reagents and solvents were of analytical grade and obtained from Merck.
The protocol for screening the antidiarrhea activity in animals was cleared by the ethical committee of Krupanidhi college of Pharmacy, Bangalore, India. Albino mice 24-28 g and Wistar rats 180-240 g and guinea pigs were obtained from animal house of Krupanidhi College of Pharmacy. The animals were housed under standard laboratory environmental condition for acclimatization for a period of 14 days prior to perform the experiments.
Preparation of plant material and phytochemical analysis
Castor oil induced diarrhea
Wistar rats were divided into 10 groups (n = 6) and, fasted for 18 h and water was provided
Gastrointestinal motility test
Albino mice of either sex were divided into 10 groups (n=6) and were fasted for 18 h and water was given
Effect on spasmogen induced contractility in isolated guinea pig ileum
The effect of the extract on histamine- and acetylcholine- induced muscle contraction of guinea pig ileum was investigated. About 10-20 mm long strips were taken from a portion 10-30 cm proximal to the ileocecal junction of the ileum. The contents of the intestine were washed off using Tyrode solution and the mesenteric residue eliminated.20 ml jacketed organ bath containing Tyrode solution at 37 °C continuously bubbled with air was used to record muscle contraction. After the initial equilibration period of about 30-60 min, concentration curves were recorded for acetylcholine (Ach), histamine (Hist) and all the solvents extracts. Closing response that gave 75% response to the agonists was then used as the dose for interaction with the extract. Different preparation was used for each agonist and each experiment was repeated at least four times .
The percentage yields of successive solvent extracts of Rhizophora mucronata bark are Petroleum ether –0.25 %, chloroform –0.5 %, ethyl acetate 1%, methanol- 2.8 % and aqueous 1%. The Phytochemical constituents present in the successive solvent extracts, pet ether (40-60C), chloroform, ethyl acetate, methanol, and aqueous extracts Rhizophora
The data was analyzed statistically using one-way analysis of variance followed by Dunnett’s ‘
Castor oil induced diarrhea
A significant delay was seen in the onset of semi- solid defecation after administration of chloroform and methanol extracts (500 mg/kg) in comparison to control (P<0.05). A dose dependent significant inhibition in the frequency of defecations was observed with chloroform and methanol extract (P<0.01) and a statistically significant inhibition in frequency of defecation were noted in the ethyl acetate extract treated animals (P<0.05) with respect to control. The aqueous extract did not show any anti-diarrhea effect (Table 2).
Values are expressed as Mean SEM, *P<0.05 significant, **P<0.01 very significance Castor oil=co
A very significant decrease (P<0.01) in the propulsion of charcoal meal through the gastro intestinal tract was exhibited in experimental animals, which was dose dependent at 250 and 500 mg/kg of the RMCE,
Effect on spasmogen induced contractility–isolated guinea pig ileum:
All the extracts, chloroform, ethyl acetate methanol and aqueous of Rhizophora mucronata did not inhibit acetylcholine or the histamine receptor of the isolated guinea pig ileum up to 10 mg/ml concentrations.
The cause for diarrhea being, infection, inflammation, immunological and nutritional and is characterized by excessive secretion of electrolytes and water into the intestinal lumen, exudation of protein and fluid from the mucosa, and altered intestinal motility, resulting in rapid transit time and an increase in wet faeces . In most instances, multiple processes are simultaneously affected involving several factors, a particular factor becoming a dominant player in a given environment; however, motility and /or secretory disturbances usually remain a common dominant in most cases .
Castor oil-induced induces diarrhea by increasing peristaltic activity and alters the permeability of the intestinal mucosa to water and electrolytes . The liberation of ricinoleic acid from castor oil results in irritation and inflammation of prostaglandin’s, which stimulates motility and secretion . The involvement of nitric oxide from neurons in the diarrhea induced by the castor oil has also been proposed . Autocoids and prostaglandin’s are involved and implicated in the induction of diarrhea ; Castor oil increases the induction of prostaglandins , causes changes in the permeability and mucosal injuries and stimulates PAF biosynthesis which may result in inflammation of intestinal mucosa . Therefore the use of castor oil induced diarrhea model in the present study is logical, since the chloroform, ethyl acetate, methanol and aqueous extract of Rhizophora mucronata bark demonstrated the dose dependent manner inhibition of castor oil –induced diarrhea. It can be assumed that anti diarrhea action was mediated by decrease in peristaltic effect and increase in water absorption and electrolytes. Rhizophora
The effect on gut motility is determined by measuring the ability of an active drug to block the contraction evoked by agonist (acetyl choline, histamine and nicotine) . The inhibition in percentage of transit of the marker, charcoal meal through the gastrointestinal tract of the albino mice was significantly seen in dose dependent manner by the chloroform, ethyl acetate, methanol and aqueous extract of Rhizophora mucronata. However, the extract failed to inhibit the contraction produced by the acetylcholine and histamine agonist in the isolated spasmogen induced contractility guinea pig ileum model experiment.
The anti diarrhea activity of the extract may also be due to the presence of denature of proteins forming protein tannates, which makes the intestinal mucosa more resistant and reduce secretion . The tannins present in the ethyl acetate and methanol extract may responsible for the observed effects in our study.
The anti diarrhea effect of Rhizophora mucronata bark extract is evident from the experimental model like- castor oil induced diarrhea, significant decrease in the number of wet feaces; gastrointestinal motility- the remarkably decrease in the propulsive movement of the gastrointestinal contents. On the isolated guinea pig ileum, the extract did not appreciably affect acetylcholine and histamine induced contractions.
The investigation concludes that folk fore use of Rhizophora
the authors acknowledge the assistance provided by the Department of Pharmacology and to the Chairman of the Krupanidhi institution for providing facility to carry out the research work.