Antihyperlipidemic, Antioxidant And Hepatoprotective Effects Of Bioactive Fractions From Gynostemma Pentaphyllum In Hyperlipidemic Mice

Objective: Hyperlipidemia （HLP） is characteristics of one or morekinds of lipids higher than normal, due to the abnormal metabolismor transportation of fat. HLP means excessive Total Cholesterol （TC）,Triglycerides （TG） or lower High Density Lipoprotein Cholesterol（HDL-C） in blood, which is a kind of systemic disease. Those lipidsare insoluble or slightly soluble in water. And they are combinedwith protein and exist in form of lipoprotein. Therefore, the HLPis usually also referred to as Hyperlipoproteinemia. Otherwise, theHLP is attributed to the category of “tanzhuo”,“xueyu” in ourTraditional Chinese Medicine. Recent research shows that the HLP isthe important pathogenic factor of Atherosclerosis （AS）, Fatty Liver（FL） and Coronary Heart Disease （CHD）, and it is the third killerof human health after Cancer and Tuberculosis. At the same time, thosediseases related to HLP, such as Obesity, Diabetes, Hypertension,present a surprising rising speed.Chinese herbal medicine is the precious treasure and treated ourdisease well in the past thousands years with Traditional Chinesemedicine theory, which has outstanding contributions. Gynostemmapentaphyllum（Thrunb.） Mak （GP） appeared form jiaqing4of Ming Dynasty （1525） by Zhu Di “Jiu Huang Ben Cao”. It is the dry grassof Cucurbitaceae Pentaphyllum, and mainly distributed in China,Korea, Japan and other countries. The GP in our experiment has abitter taste, slightly subtle and cold-nature, posses the effectsof qingrejiedu and quchutanzhuo， and could achieve the purpose oftreatment of HLP in the theory of Traditional Chinese Medicine.Our experiments based on the theories of Traditional ChineseMedicine and Modern Medicine, established a simple, feasible andstable experimental HLP model in mice. Also we observed theinfluences of different components of GP on indicators in HLP mice,to research and identify the effective part of the GP on lowing bloodlipids, anti-Oxidation and protecting liver. By the way, we stillinvestigated the mechanism, so as to provide further basis for theclinical application.Methods:60male SPF Kunming mice, were randomly divided into6groups:the normal group, model group, positive （Simvastatin） group, the GPof total extract group, the GP of50%ethanol part group and the GPresidue group,10on each group. The normal group was fed with normaldiet, and other groups were fed with High-fat Food （HFD） in the first4weeks. After4w, the normal group and model group mice were fedwith0.4ml of distilled water only. While the positive group micewere fed with Simvastatin with a dose of6.7mg·kg^-1·d^-1, and the restthree groups were fed with the GP of total extract, the GP of50%ethanol part and the GP residue respectively, with the same dose of0.34g·kg^-1·d^-1(of5.44g·kg^-1·d^-1the equivalent of raw medicinalherbs).The feed ingredients remained unchanged during the following4weeks, and the mice Body Weight （BW） of each group were recordedweekly. At the end of the dosing, some serum indexes （TC、TG、LDL-C、HDL-C、MDA、SOD、AST、ALT） were measured with biochemical kit for each group of mice. The BW of each group was weighed and the visceracoefficients of liver, spleen, kidney were calculated. Besides,partial liver samples were taken for pathological and genes analysisof PCR.Results：After the HFD of4weeks, the BW and serum TC levels in miceof model group significantly higher than in normal group （P＜0.05or P＜0.01）, Showing that the experimental fatty method was feasible.After the dosing, the BW, TC, TG, LDL-C, coefficient of liver inmice of model group were significantly higher than that of normalgroup（P＜0.05or P＜0.01）. Compared with the model group mice, thelipid abnormalities in mice of positive group, the GP total extractgroup and GP50%ethanol part of the group were significantly improved（P＜0.05or P＜0.01）, but there was no significant improvement inthe GP residue group（P＞0.05）. At the same time, the level of Srebp^-1cmRNA and HMGR mRNA were significantly down-regulated in livers ofmice in positive group, the GP total extract group and GP50%ethanolpart of the group, while the level of ApoA-I mRNA and LDL-R mRNA weresignificantly up-regulated （P＜0.05or P＜0.01）. Also, thepathological of liver and serum ALT, AST further proved the result.Finally we conclude that the GP50%ethanol part is the effectivepart of GP on hypolipidemic, anti-Oxidation and protecting liver.Conclusion:1. The HFD in the experiment can significantly increasethe BW and serum TC level, cause severe lesions and fat mold in mice,showing that the experimental fatty method was feasible and can meetthe demand of our research.2. The GP50%ethanol part can significantly reduce the BW and theserum biochemical indexes in HLP mice, which showed that it is theeffective part of GP on hypolipidemic. The molecular mechanism maydue to the down-ragulation of the level of Srebp^-1c mRNA and HMGR mRNA, and the up-ragulation of the level of ApoA-I mRNA and LDL-RmRNA.3. The GP50%ethanol part is the effective part of GP onanti-Oxidation and protecting liver.4. Although we have figured out that The GP50%ethanol part is theeffective part of GP, it is a collection of compounds and neededfurther detailed analysis. So we suggest that further extraction,separation technology and LC-MS/MS analysis method be applied tonarrowing pharmacodynamic basis of GP on hypolipidemic.