Gastro-protective effect of methanol extract of Vernonia amygdalina (del.) leaf on aspirin-induced gastric ulcer in Wistar rats

Abstract

This study investigated the protective effects of methanol extract of Vernonia amygdalina leaf (MEVA) on aspirin induced gastric ulcer in rats. Thirty Wistar rats, 150-200 g were divided into six groups as follows: Group 1 (control) rats received 2 mL/kg of propylene glycol for 28 consecutive days. Group 2 (Ulcer Control) received 150 mg/kg/day of aspirin suspended in 3 mL of 1% carboxymethylcellulose in water orally for 3 consecutive days during which the rats were fasted for the induction of ulcer. Group 3 received cimetidine at 100 mg/kg/day orally for 28 consecutive days and thereafter treated as group 2. Groups 4, 5 and 6 received MEVA orally at 200, 300 and 400 mg/kg/day respectively for 28 consecutive days and thereafter were treated with aspirin as group 2. All the animals were sacrifice at the end of the study to determine the gastric pH, gastric acidity, gastric ulcer score, haematological indices, superoxide dismutase (SOD) activity, reduced glutathione (GSH) and Lipid peroxidation (LPO) levels. The result showed that aspirin significantly (p < 0.05) increased gastric ulcer score and index, decreased gastric pH, gastric acidity, SOD activity, GSH level as well as increased LPO level. It induced significant necrosis of the stomach tissue. Administration of MEVA significantly (p < 0.05) increased gastric pH, but decreased gastric acid secretion and reversed alteration of haematological parameters. It also significantly (p < 0.05) increased SOD activity, GSH level and decreased LPO level. The results suggest that Vernonia amygdalina possesses gastro-protective properties against aspirin-induced gastric ulcer.

Keywords: Antioxidant; Aspirin; Gastric ulcer; Rat; Vernonia amygdalina.

Graphical abstract

Fig. 1

Effect of methanol extract of Vernonia amygdalina leaf on percentage body weight on aspirin induced ulcer in rats. Each value represents Mean ±S.E.M (n = 5); * = significantly different from control (p < 0.05); α = significantly different from ulcer control group (aspirin alone) (p < 0.05); β = significantly different from 100 mg/kg CMD (p < 0.05); # = significantly different from 200 mg/kg MEVA (p < 0.05); ω = significantly different from 300 mg/kg MEVA (p < 0.05).

Fig. 2

Effect of methanol extract of Vernonia amygdalina leaf on food intake on aspirin induced ulcer in rats. Each value represents Mean ±S.E.M (n = 5); * = significantly different from control (p < 0.05); α= significantly different from ulcer control group (aspirin alone) (p < 0.05); β = significantly different from 100 mg/kg CMD (p < 0.05); # = significantly different from 200 mg/kg MEVA (p < 0.05); ω= significantly different from 300 mg/kg MEVA (p < 0.05).

Fig. 3

Effect of methanol extract of Vernonia amygdalina leaf on SOD activity on aspirin induced ulcer in rats. Each value represents Mean ±S.E.M (n = 5); * = significantly different from control (p < 0.05); α = significantly different from ulcer control group (aspirin alone) (p < 0.05); # = significantly different from 200 mg/kg MEVA (p < 0.05).

Fig. 4

Effect of methanol extract of Vernonia amygdalina leaf on GSH level on aspirin induced ulcer in rats. Each value represents Mean ±S.E.M (n = 5); * = significantly different from control (p < 0.05); α = significantly different from ulcer control group (aspirin alone) (p < 0.05); # = significantly different from 200 mg/kg MEVA (p < 0.05).

Fig. 5

Effect of methanol extract of Vernonia amygdalina leaf on LPO level on aspirin induced ulcer in rats. Each value represents Mean ±S.E.M (n = 5); * = significantly different from control (p < 0.05); α = significantly different from ulcer control group (aspirin alone) (p < 0.05); β = significantly different from 100 mg/kg CMD (p < 0.05); # = significantly different from 200 mg/kg MEVA (p < 0.05).

Fig. 6

Photomicrograph of stomach of Control (CN), ulcer control, MEVA 200 mg/kg + ASPN, MEVA 300 mg/kg + ASPN, CMD 100 mg/kg + ASPN and MEVA 400 mg/kg + ASPN. CN shows intact epithelium, laminal propria, submucosa and muscularis propria. Ulcer control showed degenerative changes in forestomach and fundic regions of the stomach. There is also marked ulceration with loss of cellular constituents (brown and yellow arrow) in forestomach. Yellow arrow indicates development of subepithelial space and brown arrowhead indicates distortion of mucosal architecture. There was intact architecture of the stomach in MEVA 200 mg/kg + ASPN, MEVA 300 mg/kg + ASPN and CMD 100 mg/kg + ASPN. However, MEVA 400 mg/kg + ASPN showed sign of hemorrhage (black arrow), sloughing of necrotic submucosa and mucosa layer. Sections of stomach tissues of rats were stained with hematoxylin-eosin (Magnification: ×100). (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)