Anti-diarrheal, anti-secretory, anti-spasmodic and antiulcer activities of Acacia modesta (Mimosaceae) aerial parts

Purpose: To explore the pharmacological basis for folkloric use of Acacia modesta for treating diarrhea and gastrointestinal spasm.Methods: Acacia modesta crude extract (Am.Cr) for antidiarrheal activity (100, 300 and 1000 mg/kg) was investigated in terms of reduction in diarrhea droppings in castor-oil induced diarrhea, while antisecretory activity (300 and 1000 mg/kg) was studied in castor-oil induced model in mice. Isolated rabbit jejunum tissues were employed for in vitro experiments. For antiulcer assay, ethanol-induced gastrointestinal ulcer rat model was used.Results: Am.Cr tested positive for alkaloid, tannins and flavonoids. It exhibited protective effect against castor oil-induced diarrhea and intestinal fluid accumulation in mice at 100 - 1000 mg/kg, similar to the standard drugs, loperamide and atropine respectively. In isolated tissue (rabbit jejunum), Am.Cr concentration-dependently (0.01 - 3.0 mg/mL) produced relaxation of K+ (80 mM)-induced and spontaneous contractions at concentrations to papaverine. Am.Cr significantly inhibited (p < 0.001) ethanol-induced gastric ulceration in rats. In acute toxicity testing Am.Cr did not produce any mortality up to 5 g/kg dose.Conclusion: These results show that Acacia modesta possesses anti-diarrheal, anti-secretory, antispasmodic and anti-ulcer activities, probably mediated through dual mechanisms, including Ca2+ influx and PDE enzyme(s) inhibition. The presence of phytochemicals, such as flavonoids and tannins, suggest the validity of the acclaimed ethnomedicinal effects in hyperactive gut disorders.Keywords: Acacia modesta, Antidiarrheal, Antisecretory, Antispasmodic, Antiulce