Gastroprotective Effects of the Aqueous Seed Extract of Entada gigas (Linn.) Fawc. and Rendle (Fabaceae) in Ulcer Models in Rats

Background: The extract of Entada gigas Linn. (Fabaceae) is used for the treatment of ulcer in Nigerian local medicine. Objectives: This study investigated the gastroprotective effects of the aqueous seed extract of E. gigas on gastric ulcers in rats. Methodology: The ethanol- (EIU), pylorus ligation- (PLIU) and cold restraint stress (CRSIU)-induced ulcer models were used. The aqueous seed extract was administered at doses of 50-400 mg/kg p.o. Estimations of gastric content volume, pH and titratable acidity in PLIU test and ulcer score/index in all models were done. Results: In the EIU test, E. gigas produced significant reduction (p < 0.05) in ulcer scores, with peak effect elicited at 100 mg/kg (2.30 ± 0.99; 87.22% inhibition), compared with control (10.80 ± 0.80). This effect was comparable to that of misoprostol (3.00 ± 1.31; 83.33% inhibition). In the PLIU test, the extract caused significant reduction (p < 0.05) in the ulcer score compared with control (6.30 ± 0.70). Peak effect was elicited at the dose of 200 mg/kg (ulcer score 2.90 ± 0.83; 63.17%). This effect was comparable to that of cimetidine (2.60 ± 0.93; 66.98%). Also, the extract at 50 and 200 mg/kg, and cimetidine 100 mg/kg (0.24 ± 0.07, 1.06 ± 0.22 and 1.02 ± 0.16 mL/4 h, respectively) significantly reduced (p < 0.05) the volume of gastric content relative to control (2.32 ± 0.33 mL/4 h). In the CRSIU test, E. gigas caused significant reduction (p < 0.05) in the ulcer score, with the greatest effect produced at the dose of 50 mg/kg (0.80 ± 0.49; 92.38% inhibition), relative to control (4.20 ± 0.64). This effect was comparable to that of misoprostol (1.40 ± 0.60; 80% inhibition). Conclusion: The aqueous seed extract of E. gigas possess significant antiulcer activity mediated via cytoprotective and anti-secretory mechanisms. Keywords: Entada gigas, Fabaceae, ulcer, gastroprotective effect, cytoprotective, anti-secretory