THE EFFECT OF METHANOL RHIZOME EXTRACT OF NYMPHAEA LOTUS LINN. (NYMPHAEACEAE) IN ANIMAL MODELS OF DIARRHOEA, A RESEARCH PROJECT TOPIC ON MICROBIOLOGY
Abstract
Nymphaea lotus is one of the foremost aquatic macrophytes that have been identified in Nigerian fresh water bodies. It finds applications in the management of circulatory system disorders, digestive system disorders, infections and inflammations. This study aims to evaluate the antidiarrhoeal activity of the methanol rhizome extract of N. lotus Linn plant in laboratory animals. Shade-dried rhizome of N. lotus was extracted with 80% methanol using Soxhlet apparatus. Preliminary phytochemical screening was carried out.This revealed the presence of alkaloids, anthraquinones, carbohydrates, cardiac glycosides, flavonoids, saponins, steroids, tannins and triterpenes. The oral median lethal dose (LD50) was determined andacute toxicity test of the extract gave LD50 value greater than 5,000mg/kg p.o. in mice. The antidiarrhoeal activityof the methanol extract was determined in mice. The extract was screened for activity against castor oil-induced diarrhoea and magnesium sulphate-induced diarrhoea as well as effect on gastric transit time in mice. For castor oil-induced diarrhoea, the extract at doses of 200, 400 and 800mg/kg produced statistical significant reduction in the frequency of diarrhoea (at p<0 .001=”” 200=”” 200mg=”” 3mg=”” 400=”” 400mg=”” 800=”” 800mg=”” a=”” along=”” also=”” and=”” antidiarrhoeal=”” antimotility=”” at=”” atropine=”” charcoal=”” comparable=”” delay=”” diarrhoea=”” diarrhoeawas=”” doses=”” drug=”” effect=”” extract=”” frequency=”” greater=”” groups=”” in=”” intestinal=”” kg=”” ll=”” loperamide=”” magnesium=”” meal=”” mg=”” of=”” onset=”” p=”” produced=”” protection=”” reduced=”” reduction=”” respectively.=”” respectively=”” significant=”” significantly=”” span=”” standard=”” statistically=”” sulphate-induced=”” the=”” to=”” tract=”” transit=”” treated=”” with=””> compared to the extract. Effect of methanol rhizome extract of N. lotus on isolated rabbit jejunum and guinea pig ileum was determined. The methanol rhizome extract ofNymphaea lotus at low concentration (4×10-4 – 6.4×10-2mg/ml) had contractile effect on the tone of contraction of the rabbit jejunum while at higher concentrations (8×10-2 -512×10-2 mg/ml) produced significant reduction in the tone and rate of spontaneous contraction of rabbit jejunum. Interaction of the extract,at concentration that causes relaxation, with acetylcholine,attenuated the effect of the latter in a manner similar to atropine.The methanol rhizome extract of N. lotus at lower concentrations (4×10-4 to 2×10-2 mg/ml) has no effect on contraction of the guinea pig ileum while higher concentrations (4×10-2 – 512×10-2 mg/ml) produced significant relaxant activity on guinea pig ileum. Interaction of the extract with histamine attenuated the effect of the latter which may be as a result of physiologic antagonism.This study has shown that the methanol rhizome extract of N. lotus has antidiarrhoeal properties thus justifying its use by the local population for this purpose.
CHAPTER ONE
1.0 INTRODUCTION
Diarrhoea is characterized by increased frequency of bowel movement, wet stool and abdominal pain (Ezekwesili et al., 2004). Diarrhoeal disease account for nearly 1.3 million deaths a year among children under-five years of age, making it the second most common cause of child deaths worldwide, with half of the deaths occuring in just five countries: India, Nigeria, Afghanistan, Pakistan and Ethiopia (UNICEF, 2012).
