Assessment of the Potential Mechanisms of Anti-diarrhoeal Activities of Ethanol Extract of Monoon longifolium Leave in Wistar Rat

Background: Numerous diseases related to diarrhea are the primary cause of morbidity and mortality in underdeveloped countries, accounting for hundreds of thousands of deaths annually. Polyalthia longifolia, the false ashoka, commonly referred to as Monoon longifolium is a tree species from Asia. It is commonly found in southern india, Sri Lanka and Nigeria. Polyalthia longifolia has been utilized for decades to treat an extensive variety of illnesses, including diarrhea.

Method: The plant was extracted with ethanol using cold maceration. Preliminary qualitative and quantitative phytochemical screening of ethanol extract of Polyalthia longifolia leaf was conducted using the techniquees of Harbone (1998); Trease and Evans (1978). The Lorke (1983) approach was used to calculate the Median Lethal Dose (LD50). Diarrhea caused by castor oil was produced using the Awouter et al., 1973 method. The testing for gastrointestinal transit was conducted using the Mascolo et al. (1996) technique. The Tietz (1994) method was used to conduct the electrolyte levels assay. The assay for kidney function indicators was conducted using Bartels and Bohmer's (1972) methodology.

Results: The results of phytochemical screening showed that alkaloids and tannins occurred in high concentration, flavonoids and steroids occurred in moderate concentration, whereas terpenoids, glycosides and phenolic acid occurred in lowest concentration. The acute toxicity study revealed that the plant extract was not toxic even at the dose of 5000 mg/kg. Groups treated with 200,400, and 600 mg/kg b.w of extract showed significant (P < 0.05) inhibition in the frequency of defecation of wet feces and total fecal output compared with positive control. Similarly, Groups treated with 200, 400, and 600 mg/kg body weight of extract demonstrated significant (P < 0.05) antimotility activity when compared with the positive control. However, groups treated with 200,400 and 600mg/kg body weight showed a significant (P < 0.05) increase in chlorine and sodium with corresponding decrease in bicarbonate and potassium level when compared with the positive control. The results from kidney function markers showed that groups treated with 200, 400 and 600 mg/kg b.w in a dose dependent manner showed a significant (p < 0.05) reduction in creatine and urea when compared with positive control.

Conclusion: The ethanol leaf extract of Polyalthia longifolia has considerable antidiarrheal activity on castor oil-induced diarrhea and gastrointestinal motility models, confirming the reason for its wide use in traditional treatment of diarrheal conditions.