Purpose: To determine the gastroprotective activity and mechanisms of protection of the methanol
extract of
Bauhinia purpurea
leaves (MEBP) using ethanol-induced gastric ulcer model.
Methods: Male Sprague Dawley rats (n = 6) were administered orally with 10 % DMSO, 100 mg/kg
ranitidine or MEBP (50, 250 and 500 mg / kg) daily for 7 consecutive days prior to subjection to the
ethanol-induced gastric ulcer assay. The mechanisms of gastroprotection were determined based on: i)
antisecretory activity via pylorus ligation assay; ii) the role of nitric oxide (NO) and sulfhydryl group via
pre-treatment of MEBP-treated rats with the respective N-nitro-L-arginine methyl ester (L-NAME) or
carbenoxolone (CBX) followed by the ethanol-induced assay; and iii) antioxidant activity using
superoxide anion radical scavenging assay and, oxygen radical absorbance capacity (ORAC) assay.
Ranitidine (100 mg / kg) was used as the reference drug. .
Results: MEBP exhibited a significant (p < 0.05) and dose-dependent gastroprotective activity against
ethanol-induced gastric ulcer with ulcer formation ranging between 0 and 74 % (indicated by decrease
in ulcer area from 21.3 to 5.5 mm
2). The macroscopic observation was in line with the microscopic
findings and further supported by the histological scores suggesting the antiulcer potential of MEBP.
MEBP also significantly (p < 0.05) reduced volume gastric juice, as well as its free and total acidity while
increasing its pH. Moreover, this activity was significantly (p < 0.05) modulated in the presence of
sulfhydryl group, but not NO. The extract also exhibited significant (p < 0.05) antioxidant activity.
Conclusion: MEBP exerts gastroprotective activity partly via its antisecretory and antioxidant activities,
as well as by modulation of sulfhydryl group, but not NO action.
