Antioxidant Effects of Codonopsis pilosula Reverse Glucose Tolerance Impairment-Induced Testicular Dysfunction.

Abstract

Glucose tolerance decline and insulin resistance often accompanied functional decline in multiple organs. The present study was to examine whether administration of Danseng (Codonopsis pilosula) root extract to adult male rats will reverse glucose tolerance impairment induced testicular dysfunction. The adult Sprague Dawley male rats were divided into three groups (n=6): control group, fructose alone group, fructose plus danseng group. In the fructose group, the tap drinking water was replaced by a 10% fructose solution for 8 weeks. All the rats administered with fructose got glucose tolerance impairment. In the fructose plus danseng group, after the adult male rats got glucose tolerance impairment, Danseng were added by 1 mg/kg body weight in their drinking water for another 4 weeks. Control rats were having standard chow and tap drinking water ad libitum. The rats were anaesthetized and blood was removed from the inferior vena cava and collected into heparinized tubes. The testis was excised and weighed, and used for biochemical analysis. Samples were kept frozen (-20°C) until assay. Activities of antioxidant enzymes in testis were measured by assay kit. The protein expression of steroidogenic acute regulatory protein (StAR), P450 side chain cleavage (P450scc), antioxidant enzymes, and protein kinase A (PKA) were detected by Western blot. Rats that received Danseng experienced a significant increase in blood testosterone level compared to the fructose group (p < 0.01). There were found no significant changes in weight of testis and the relative organ weight. No significant changes in testicular lipid peroxidation were observed between the three groups. The administration of fructose resulted in increased activity of superoxide dismutase (SOD) compared to control group (p<0.05). Combination of fructose and Danseng significantly enhanced the activity of SOD, catalase and glutathione peroxidase (GPx) compared to control group (p<0.05). A correspondent higher increase of testicular SOD expression was also observed in the fructose, and fructose plus Danseng group. The expression of StAR was also increased significantly in the fructose group compared with the control group (p<0.05). Combination of Danseng resulted in StAR expression recovered near the expression of control group. In conclusion, the obtained results strongly suggest that the consumption of fructose decreased the plasma testosterone level due to the declined testicular function, including imbalance activities of antioxidant enzymes, and resulted the compensatory increased StAR expression. The combination of Danseng has protective effects on testicular tissues and can reverse the effect of fructose on antioxidant enzymes. (poster)