Objecive : Liriopis Tuber is a medcial herb that has been used in Korean medicine for a long time. It is rich in polyphenol and its insulin secretion and fatty liver inhibition are confirmed. In addition, it is found that its antioxidant effects and anti-lipid effects increased by the heating process. This study is aimed to compare the changes in antioxidative capacity of Liriopis Tuber by steaming process and to compare the effects in hyperlipidemia induced rats fed high cholesterol diet between simvastatin and Liriopis Tuber by steaming process.
Methods : We compared the free radical scavenging activity of Liriopis Tuber (LT0), Liriopis Tuber with 6 times steaming process (LT6) and Liriopis Tuber with 9 times steaming process (LT9) and the contents of polyphenol and flavonoid between LT0, LT6, LT9. The SD rats were divided into six groups: normal diet (N), high cholesterol diet (Veh), high cholesterol diet plus simvastatin 5 ㎎/㎏ (Sim), high cholesterol diet plus LT0 extract 200 ㎎/㎏ (LT0), high cholesterol diet plus LT6 extract 200 ㎎/㎏ (LT6) and high cholesterol diet plus LT9 extract 200 ㎎/㎏ (LT9). We compared the TC, TG, HDL, LDL contents and ROS from each serums. Protein expression in liver tissues related to antioxidant and cholesterol was analyzed. We also performed optical microscopic analysis through liver tissue staining.
Results : In vitro, DPPH and ABTS radical scavenging activity, polyphenol content and flavonoid content were the highest in LT9. In vivo, LT9 significantly decreased liver weight in hyperlipidemic rats. TC, TG, LDL-c, AI and CRF decreased and HDL-c increased with increasing steaming frequency. AST, ALT, creatinine, and BUN decreased with increasing steaming frequency. ROS decreased only in LT9, and SOD, catalase and GPx increased with increasing steaming frequency. p-AMPK increased and SREBP-2, p-ACC, and HMGCR decreased with increasing steaming frequency. Liver staining showed a decrease in hepatic fat accumulation of LT9. LT9 showed significant results in all experiments.
Conclusion : The antioxidant activity of Liriopis Tuber increased by steaming process. In addition, LT9 showed significance of anti-lipid effect and improved fatty liver of hyperlipemia induced rats fed on high cholesterol diet. And liver function and renal function were also improved. In conclusion LT9 could be used effectively as a treatment for hyperlipidemia instead of statins.