Intervention Of Curcuminoids On Liver Injury Exposed To Cadmium In Rats

Objective The main ingredient of curcuminoids(Curs) is curcumin(Cur Ⅰ),demethoxycurcumin(Cur Ⅱ) and bisdemethoxycurcumin(Cur Ⅲ). Obtaining the optimum extraction solvent by extract experiment on tumeric, separate three monomers by column chromatography experiment to get the best column chromatography conditions. The present study consider that oxidative damage is the cadmium toxicity mechanism to the body, and Curs have been shown to have antioxidant activity. The purpose of this study is to compare monomers’ antioxidant activity in vitro, resesrch the intervention of Curs monomers on the liver injury in rats exposed to cadmium from antioxidant level. Provide mechanism and preliminary theoretical basis of cadmium poising in clinical and occupational.Methods 1 Isolation and purification of Curs: using 9 common extraction solvents:water, 50 % ethanol, 70 % ethanol, 80 % ethanol, ethanol, methanol, acetone, ethyl acetate, ethyl acetate: ethanol(1:1) to extract Chinese medicine tumeric under the same conditions, detect the content of curcumin, demethoxycurcumin and bisdemethoxycurcumin in each extraction solution by HPLC, determine the best extraction solvent. Investigate column chromatography conditions, including: eluents,filling materials, the filling amount and the volume of sample, to get optimum separation conditions of three monomers. 2 Antioxidant experiments: detecte and compare antioxidant activity between curcumin and bisdemethoxycurcumin. 3 Intervention experiments on rats exposed to cadmium: 36 rats were divided into blank group,cadmium group, curcumin low dose(25 mg/kg) group, curcumin high dose(50 mg/kg)group, bisdemethoxycurcumin low dose(25 mg/kg) group and bisdemethoxycurcumin high dose(50 mg/kg) group randomly. Injected 2.0 mg/kg cadmium chloride by intraperitoneal for 6 times, once every two days, 12 days; While gavage drugs for 6weeks. Detected energy of aspartate aminotransferase(AST), alanine aminotransferase(ALT), superoxide dismutase(SOD), content of malondialdehyde(MDA) and level of caspase-3 in liver tissue. Observed pathological section of liver by hematoxylin-eosin(HE) staining in liver tissue, statistical analysis using SPSS17.0, compared intervention between curcumin and bisdemethoxycurcumin on liver injury in rats exposed to cadmium.Results 1 Experiments show that methanol have the maximum extraction rate on curcuminoids, but from the view of economic and security point, 70 % ethanol is more suitable. The best separation conditions is column diameter to height 1:8 packed silica into column with dry, fill samples according to 1:120 in wet, use eluents as chloroform:formic acid(100:0.7), chloroform: methanol: formic acid(99:1:0.7) and(98:2:0.7) to gradient elution, separate three monomers of high purity. 2 Oxidation activity results show that curcumin is much higher than bisdemethoxycurcumin on DPPH scavenging rate. 3 Cadmium experiment show the levels of AST, ALT, Caspase-3 and MDA are significantly increased, activity of SOD is significantly lower in cadmium group,compared with the control group there is a significantly difference(P<0.05). Level of AST, ALT, Caspase-3 and content of MDA are lower than the cadmium, SOD activity increased in administration group. Pathological section and electron microscopy results show cadmium in liver cells of rats massive necrosis, cell ultrastructure are badly damaged, compared to cadmium group the cell structure is relatively complete set of administration group, cell status of curcumin high-dose group is near the control group.Conclution Extract Curs with 70 % ethanol, to obtain optimum conditions of isolate monomers. Intervention experiments on rats exposed to cadmium show that curcumin and bisdemethoxycurcumin can intervene liver injury of rats exposed to cadmium, and this relate to the antioxidant activity of Curs; Overall Cur Ⅰ have the stronger intervention than Cur Ⅲ.