Antidiarrheal activity of alcoholic and aqueous extracts of stem bark of Thespesia populnea in rodents

The objective of the study is to investigate the aqueous (AQTP) and alcoholic extracts (ALTP) of stem barks of Thespesia populnea (Malvaceae) for their antidiarrheal activity in rodents. Stem bark was extracted with alcohol and water successively. Preliminary phytochemical investigation was carried out to identify various phytochemical constituents present in the extracts. It was found that the AQTP contains alkaloids, carbohydrates, glycosides, saponins, proteins, flavonoids, tannins and phenolic compounds; ALTP contained alkaloids, carbohydrates, glycosides, saponins, proteins, steroids, flavonoids, tannins and phenolic compounds. Acute oral toxicity of ALTP and AQTP were conducted as per OECD guidelines 425. Acute toxicity studies revealed that both the extracts are safe upto 2000mg/kg. The antidiarrheal activity was observed in three experimentally induced diarrhea models i.e. Castor oil induced diarrhea; Prostaglandin E₂ (PG-E₂) induced enteropooling in rats and charcoal meal test in mice. In castor oil induced model ALTP and AQTP showed significant dose dependent reduction of cumulative wet faecal mass. In PG-E₂ induced enteropooling model, ALTP (100, 200 and 400mg/kg, p.o.) and AQTP (50,100 and 200mg/kg, p.o) inhibit PG-E₂ induced secretions. Similarly in charcoal meal test ALTP and AQTP decreased the movement of charcoal indicating its antimotility activity. It was observed that AQTP is having more potent anti-diarrheal activity than ALTP in these models.