Gastroprotective effects of Corchorus olitorius leaf extract against ethanol-induced gastric mucosal hemorrhagic lesions in rats

Abstract

Background and aim: Corchorus olitorius is a medicinal plant traditionally utilized as an antifertility, anti-convulsive, and purgative agent. This study aimed to evaluate the gastroprotective effect of an ethanolic extract of C. olitorius against ethanol-induced gastric ulcers in adult Sprague Dawley rats.

Methods: The rats were divided into seven groups according to their pretreatment: an untreated control group, an ulcer control group, a reference control group (20 mg/kg omeprazole), and four experimental groups (50, 100, 200, or 400 mg/kg of extract). Carboxymethyl cellulose was the vehicle for the agents. Prior to the induction of gastric ulcers with absolute ethanol, the rats in each group were pretreated orally. An hour later, the rats were sacrificed, and gastric tissues were collected to evaluate the ulcers and to measure enzymatic activity. The tissues were subjected to histological and immunohistochemical evaluations.

Results: Compared with the extensive mucosal damage in the ulcer control group, gross evaluation revealed a marked protection of the gastric mucosa in the experimental groups, with significantly preserved gastric wall mucus. In these groups, superoxide dismutase and malondialdehyde levels were significantly increased (P < 0.05) and reduced (P < 0.05), respectively. In addition to the histologic analyses (HE and periodic acid-Schiff staining), immunohistochemistry confirmed the protection through the upregulation of Hsp70 and the downregulation of Bax proteins. The gastroprotection of the experimental groups was comparable to that of the reference control medicine omeprazole.

Conclusions: Our study reports the gastroprotective property of an ethanolic extract of C. olitorius against ethanol-induced gastric mucosal hemorrhagic lesions in rats.

Keywords: Corchorus olitorius; gastric ulcer; gastroprotection; histology; immunohistochemistry.

Figure 1

Gross appearance of the gastric mucosa in rats. (a) Normal control group. (b) Group pretreated with carboxymethyl cellulose (CMC) (ulcer control). Severe injuries of the gastric mucosa are apparent with extensive hemorrhagic necrosis. (c) Rats pretreated with omeprazole (20 mg/kg). The gastric mucosa injuries are mild compared with the ulcer control rats. (d) Rats pretreated with 50 mg/kg Corchorus olitorius show moderate injuries to the gastric mucosa. (e) Rats pretreated with 100 mg/kg C. olitorius have moderate injuries of gastric mucosa. (f) Pretreatment with 200 mg/kg C. olitorius lessens the gastric mucosa injuries. (g) Pretreatment with 400 mg/kg C. olitorius completely protects the gastric mucosa.

Figure 2

HE staining of the gastric tissue in rats (20×). (a) Normal control group. (b) Rats pretreated with carboxymethyl cellulose (CMC) (ulcer control). Disruption to the gastric epithelium, necrotic lesions penetrated deeply into the mucosa, extensive edema in the submucosal layer and leukocyte infiltration are apparent. (c) Rats pretreated with omeprazole (20 mg/kg). Mild disruption of the surface epithelium mucosa was present, but deep mucosal damage was absent. (d, e, f and g) The rats pretreated with 50, 100, 200, and 400 mg/kg Corchorus olitorius, respectively. There was no disruption to the surface epithelium and no edema or leukocyte infiltration into the submucosal layer.

Figure 3

Glycoprotein secretion (periodic acid-Schiff [PAS] staining) of the gastric tissue in rats (20×). (a) Normal control group. (b) Ulcer control group. (c) Omeprazole-treated group. (d, e, f and g) Groups pretreated with 50, 100, 200 and 400 mg/kg Corchorus olitorius extract, respectively.

Figure 4

Immunohistochemical analysis of Hsp70 expression in the gastric mucosa of rats (20×). (a) Normal control group. (b) The ulcer control group. (c) Omeprazole-treated group. (d, e, f and g) Groups pretreated with 50, 100, 200, and 400 mg/kg plant extract, respectively.

Figure 5

Immunohistochemical analysis of Bax expression in the gastric mucosa of rats (20×). (a) Normal control group. (b) Ulcer control group. (c) Omeprazole-treated group. (d, e, f and g) Groups pretreated with 50, 100, 200, and 400 mg/kg plant extract, respectively.