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-kappaB), transforming growth factor beta(1) (TGF-beta(1)) 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-kappaB 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.