Inhibitory Effects of Cinnamic Aldehyde Semicarbazone on Activity of Xanthine Oxidase

Abstract:

The inhibition mechanism of cinnamic aldehyde semicarbazone on xanthine oxidase activity was examined. The experiment examined the IC₅₀ values, inhibitory type, and the inhibitory constant value of cinnamic aldehyde semicarbazone on xanthine oxidase to analyze the oxidation of xanthine. The inhibition type was determined by Lineweaver - Burk double reciprocal plot and the corresponding inhibition constants (K_Ｉ and K_ＩＳ) were calculated. The experiment also examined the effects of cinnamic aldehyde semicarbazone on the concentration of serum uric acid，the activity of serum xanthine oxidase and liver xanthine oxidase in mice. Cinnamic aldehyde semicarbazone showed significant inhibitory effects on the activity of xanthine oxidase with IC₅₀ of 55.48 μmol/L，and it was the reversible inhibitor and competitive-uncompetitive mixed type inhibitor with K_Ｉ of 27.25 μmol/L and K_ＩＳ of 50.30 μmol/L. Compared with the model group, cinnamic aldehyde semicarbazone could significantly reduce the concentration of serum uric acid，the activity of serum xanthine oxidase and liver xanthine oxidase in mice (P <0.05，n =10). The active sequence was allopurinol>cinnamic aldehyde semicarbazone>cinnamyl aldehyde. Cinnamic aldehyde semicarbazone had significant inhibitory effects on the activity of xanthine oxidase. It could also significantly reduce the concentration of serum uric acid, the activity of serum xanthine oxidase and liver xanthine oxidase in mice. These results suggest the utilization of cinnamic aldehyde semicarbazone as a new drug candidate for reducing uric acid and treating gout.