Gastroprotective effects of a new zinc(II)–curcumin complex against pylorus-ligature-induced gastric ulcer in rats

Zn(II)–curcumin, a mononuclear (1:1) zinc complex of curcumin was synthesized and examined for its antiulcer activities against pylorus-ligature-induced gastric ulcer in rats. The structure of Zn(II)–curcumin was identified by elemental analysis, NMR and TG–DTA analysis. It was found that a zinc atom was coordinated through the keto-enol group of curcumin along with one acetate group and one water molecule. Zn(II)–curcumin (12, 24 and 48 mg/kg) dose-dependently blocked gastric lesions, significantly reduced gastric volume, free acidity, total acidity and pepsin, compared with control group (P < 0.001) and curcumin alone (24 mg/kg, P < 0.05). Reverse transcriptase polymerase chain reaction (RT-PCR) analysis showed that Zn(II)–curcumin markedly inhibited the induction of nuclear factor-kappa B (NF-κB), transforming growth factor beta1 (TGF-β1) and interleukin-8 (IL-8), compared with control group (P < 0.05). These findings suggested that Zn(II)–curcumin prevented pylorus-ligation-induced lesions in rat by inhibiting NF-κB activation and the subsequent production of proinflammatory cytokines, indicating a synergistic effect between curcumin and zinc. An acute toxicity study showed that mice treated with SDs of Zn(II)–curcumin (2 g/kg) manifested no abnormal signs.