Effects of ghrelin on sulfite induced changes in lipid peroxidation, spatial memory, and locomotor activity in rats

Humans are constantly exposed to sulfites and their derivatives, both endogenously and exogenously. Recent studies have shown that sulfite and its derivatives can cause oxidative stress. . Ghrelin has been reported to possess antioxidant properties and stimulates neurogenesis in hippocampal progenitor cells. This study aimed to investigate the effects of ghrelin on sulfite-induced changes in hippocampal oxidative status, spatial learning and locomotor activity in rats.

Forty male albino Wistar rats were randomized into four groups as follows; Group 1: Control (C); Group 2: Sodium metabisulfite (Na2S2O5) treated (S); Group 3: Ghrelin treated (G); Group 4: Na2S2O5 + Ghrelin treated (SG). Sodium metabisulfite (100 mg/kg/day) was given by gastric gavage, and ghrelin (20 µg/kg/day) was administered intraperitoneally for 5 weeks. Thiobarbituric acid reactive substances (TBARS) were measured through fluorometric method. The spatial memory and locomotor activity of the rats were evaluated by Y-maze test.

Y-maze results revealed an enhancement of short-term spatial learning and memory in S and SG groups compared to C group. TBARS levels were increased significantly in S group with respect to C group. The increase in TBARS levels induced by sulfite was completely prevented by ghrelin in SG group.

We suggest that systemic ghrelin administration might ameliorate ingested sodium metabisulfite-induced hippocampal oxidative damage without providing any changes in spatial learning, memory and locomotion. Further investigation concerning the mechanism of ghrelin action in hippocampus might provide valuable information for developing new therapeutic approaches to attenuate oxidative stress in hippocampal tissue.