Antioxidant Effects of Eugenol on Oxidative Stress Induced by Hydrogen Peroxide in Islets of Langerhans Isolated from Male Mouse.

Background: The antioxidant system in islets of Langerhans is weak, which can lead to diabetes. Meanwhile, the main component of cloves that produce antioxidant effects is eugenol. Accordingly, the present study was conducted to investigate the antioxidant effect of eugenol on oxidative stress induced by hydrogen peroxide (H₂O₂) in islets of Langerhans isolated from the male mice.

Materials and methods: In this experimental study, adult Naval Medical Research Institute (NMRI) mice (20-25 g) were prepared. The collagenase digestion method was used for dissecting the islets of Langerhans. H₂O₂ 50 μM was administered for 30 min to induce oxidative stress, with 50, 100, and 200 μM of eugenol employed for 2 hours before the administration of H₂O₂. The experimental groups were divided into five groups: (control, H₂O₂, and H₂O₂+eugenol 50, 100, and 200 μM). Finally, the islet's lipid peroxidation and antioxidants levels were measured by the ELISA assay method.

Results: Malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), and catalase (CAT) increased in all groups when compared to the control (P < 0.05). MDA diminished in H₂O₂+eugenol 50, 100, and 200 μM (P < 0.01) groups versus the H₂O₂. TAC was elevated when eugenol 50, 100, and 200 μM was administered in oxidative stress-induced islets (P < 0.001). Also, CAT increased in the H₂O₂+eugenol 50 (P < 0.05) group in comparison with the H₂O₂ group.

Conclusions: In conclusion, H₂O₂ induced oxidative stress and lipid peroxidation in the islets, and administration of eugenol recovered these alterations by raising the level of TAC and CAT, while reducing MDA as a lipid peroxidation biomarker.