Background: This study aimed to investigate the protective effects of gallic acid
(GA) in the rat intestine against ischaemia-reperfusion (IR) injury.
Materials and methods: Thirty male Wistar albino rats with a mean weight of
200–250 g were used. Animals were categorized into the sham, IR, and IR+GA
groups. Ischaemia of the intestine was induced for 3 h by occluding the superior
mesenteric artery (SMA) and then left for 3 h of reperfusion. In the IR+GA group,
after ischaemia induction, 50 mg/kg GA was orally administered to the animals.
Blood samples were collected for biochemical assays. Intestinal tissues were excised
for histopathologic and immunohistochemical processing.
Results: Malondialdehyde (MDA) levels were increased, and catalase (CAT) and
glutathione (GSH) levels were decreased in the IR group compared to the sham
group. After GA treatment, MDA levels decreased and CAT and GSH levels increased
in the GA-treated group compared to the IR group. In the sham group,
normal intestinal histology was observed. In the IR group, the villi structures were
completely degenerated. In the IR+GA group, histology was improved after GA
treatment. In the sham group, the caspase-3 reaction was generally negative in
the epithelium and glands. In the IR group, the caspase-3 reaction increased in
apoptotic bodies and inflammatory cells. The caspase-3 reaction was negative
in goblet cells and the epithelium. A moderate caspase-3 reaction was observed
in the IR+GA group. The beclin-1 reaction was negative in epithelial cells and
goblet cells in villi in the sham group. In the IR group, the beclin-1 reaction was
positive in the degenerated villi. An intense beclin-1 reaction was also observed in
some inflammatory cells. After GA treatment, the beclin-1 reaction was positive in
a few cells. In general, moderate beclin-1 positivity was observed.
Conclusions: Gallic acid, with its antioxidative effect, inhibited the apoptotic pathway
(caspase-3) through beclin-1 regulation.