Study On The Effect And Mechanism Of Longshengzhi Capsules In The Treatment Of Hyperlipidemia

Hyperlipidemia is a systemic disease caused by lipid metabolism disorders.Hyperlipidemia is usually characterized by high levels of total cholesterol,triglyceride and low density lipoprotein cholesterol（LDL-C）,and low level of high density lipoprotein cholesterol（HDL-C）in plasma,which could be resulted by genetic and environmental factors.Longshengzhi Capsules（LSZ）（National Medicine Standard Z20010059）is produced by Shaanxi Buchang Pharmaceutical Co,Ltd.Its main ingredients include Astragalus,Leech,Chuanxiong,Angelica,Safflower,Peach Kernel,Red Radix,Wood Incense,Shichangpu,Dilong,Mulberry parasitic and Acanthopanax senticosus extract.LSZ can promote blood circulation and remove blood stasis.Pharmacological studies have shown that LSZ can reduced blood viscosity and prevent thrombosis and arteriosclerosis,indicating that LSZ may play a role in blood lipid lowering.Hence,we performanced experiments to study the effects and mechanisms of LSZ on lowering blood lipids both in vitro and in vivo,and we determined the following results:（1）LSZ extract is sufficient to inhibit lipid accumulation in Hep G2 cells.Mechanistically,LSZ extract increased the expression of LDL receptor（LDLR）by inhibiting the expression of proprotein convertase subtilisin/kexin type 9（PCSK9）expression,thereby improving cholesterol me Tabolism.But LSZ extract had little effect on cholesterol synthesis.（2）To determine whether LSZ can lower blood lipid levels in vivo,we used C57BL/6J mice conducted animal experiments.Eight-week-old C57BL/6J mice were randomly divided into three groups,control group,low-dose group and high-dose group.The mice in control group were fed with high-fat diet（HFD）for 2 weeks,in low or high dose group were fed with HFD containing LSZ for 850 mg/100 g food or 2 g/100 g food for 2 weeks,respectively.At the end of experiment,mice were sacrificed,and blood and liver tissues were collected.We used automatic biochemical analyzer to detect serum lipid levels,and found that LSZ reduced serum triglyceride levels,but had little effect on cholesterol levels.We conducted H&E staining of hepatic paraffin section and Oil red O staining of frozen section,and showed that LSZ reduced liver lipid accumulation.In addition,we quantified liver cholesterol,triglycerides and free fatty acids using assay kits and found that LSZ reduced triglyceride content in the liver.Furthermore,we showed that LSZ protected HFD-induced liver injury through reducing aspartate aminotransferase（AST）,alanine aminotransferase（ALT）and alkaline phosphatase（ALP）levels.Mechanistically,LSZ inhibited triglyceride synthesis by reducing the expression of key genes for triglyceride synthesis,including fatty acid synthetase enzymes fatty acid synthase（FASN）and diacylglycerol acyltransferase 1（DGAT1）,and accelerated the triglyceride hydrolysis me Tabolism by up-regulating the expression of triglyceride-related genes comparative gene identification-58（CGI-58）,adipose triglyceride lipase（ATGL）,hormone-sensitive triglyceride lipase（HSL）and lipoprotein lipase（LPL）.（3）To explored the safety and effectiveness of LSZ in treating hyperlipidemia,we used 8-week-old Apo E^-/-mice for the long-term treatment.Apo E^-/-mice were randomly divided into 3 groups（10/group）:control group,low dose group and high dose group,and treated as described as C57BL/6J mice.After 16-week treatment,we found that triglyceride levels in both serum and liver were significantly reduced by LSZ.We found that LSZ still protected HFD-induced liver damage during long-term treatment evidenced by decreased AST,ALT and ALP levels,which further confirms the effectiveness and safety of LSZ.Mechanistically,we revealed that LSZ can not only reduce the expression of key genes for triglyceride synthesis including FASN and DGAT1,but also up-regulate the expression of genes related to triglyceride hydrolysis including CGI-58,ATGL,HSL and LPL.These data indicate that LSZ reduces triglyceride levels in both liver and serum through the similary mechanism in C57BL/6J mice.In summary,our study demostrates that LSZ can reduce triglyceride levels in both serum and liver in mice.At the same time,we also clarify the lipid-lowering mechanism of LSZ.Moreover,we verified the safety and effectiveness of LSZ in hyperlipidemia during long-term treatment.These data are expected to provide theoretical support for the further clinical application of LSZ.