Phytochemical composition, antioxidant, brine shrimp lethality and antidiarrheal activities of methanol extract of Erythrina senegalensis leaf

This study investigated the phytochemical composition, antioxidant, and antidiarrheal activities of the methanol extract of Erythrina senegalensis (MEES) leaf. The fresh leaf Erythrina senegalensis was processed and extracted using cold maceration method with 80% hydro-methanol. The total phenols and flavonoids content were determined using standard protocols. The ferric reducing antioxidant power and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay of MEES were evaluated at 25-400 μg/mL concentration. The antidiarrheal activity of MEES was determined using castor-oil induced diarrhea, enteropooling and intestinal transit model in mice at the dose of 100, 200 and 400 mg/kg. The total flavonoid concentration and total phenol concentration of MEES are 252.33 ± 0.67 mg RE/g MEES and 36.05 ± 0.35 mg GAE/g MEES, respectively. The MEES produced concentration-dependent increase in free radical scavenging activity, which was significantly (p < 0.05) lower than that of ascorbic acid. At four hours post treatment, the MEES (100, 200 and 400 mg/kg) and loperamide (3 mg/kg) produced 27, 32, 40 and 99% inhibition of diarrhoea respectively, when compared with the distilled water treated group. The MEES (200 and 400 mg/kg) and loperamide (3 mg/kg) produced 13, 25 and 52% inhibition of peristaltic index respectively, relative to the distilled water treated group. The MEES (100, 200 and 400 mg/kg) and loperamide (3 mg/kg) produced 19, 12, 15 and 28% inhibition of intraluminal fluid content accumulation respectively, when compared to the distilled water treated group. The MEES demonstrated mild antidiarrheal property which validates its use as antidiarrheal agent in folkloric medicine.