The Mechanisms Of Shengma(Cimicifuga Foetida L.)Extracts Ameliorating Diet-Induced Obesity And Related Metabolic Diseases In Mice

Globally,the high-calorie diet is an important cause of rising rates of obesity.Obesity and related metabolic diseases,such as type 2 diabetes,fatty liver,and hyperlipidemia,reduce life quality and lifespan,which leads to serious social problems and economic burden.It is of great significance for improving diet-induced obesity and related metabolic diseases to seek natural products with anti-obesity activities from drug and food homologous drugs.Cimicifuga foetida L.(CF)is a traditional drug and food homologous Chinese medicine.It has the functions of relieving exterior syndrome and treating anthema,eliminating heat and detoxic,and elevating blood and “Qi”.Modern pharmacological studies have found that Cimicifuga has the effects of ameliorating menopausal syndrome,osteoporosis,hyperlipidemia.However,the effects of CF on diet-induced obesity and associated metabolic diseases have not been reported.In this study,the effects of CF and its extracts on diet-induced obesity and related metabolic disorders were systematically investigated.First of all,we tested the effects of CF on obesity and insulin resistance induced by a high-fat diet in mice.The 5-week-old C57BL/6 mice were fed on a low-fat diet(LFD),high-fat diet(HFD),or HFD supplemented with CF for 12 weeks,respectively.The results showed that CF significantly reduced the body weight and improved obesity-related metabolic symptoms such as insulin resistance,fatty liver,and hyperlipidemia of mice on a high-fat diet.Furthermore,we scientifically investigated the anti-obesity activities of crude extract of CF(CCF),petroleum ether(PE)extract of CF(PCF),ethyl acetate extract of CF(ECF),n-Bu OH extract of CF(BCF)and aqueous extract of CF(ACF)in mice fed on a high-fat diet.The results showed that ECF had a similar effect to CF on improving diet-induced obesity and related metabolic disorders in mice,and was the main active component in CF.Mechanistic studies revealed that CF and ECF could promote lipolysis of adipose tissue and increase the utilization rate of lipids in mice on a high-fat diet.In addition,CF and ECF could also increase energy consumption by promoting the browning of white adipose tissue to improve obesity and related metabolic disorders induced by a high-fat diet in mice.We evaluated the effects of 5 dominant compounds isolated from ECF on the differentiation of 3T3-L1 preadipocytes.The results showed that actein and 23-epi-26-deoxyyactein(DA)had significant inhibitory effects on the adipogenesis of preadipocyte.Moreover,actein had a stronger inhibitory effect on adipogenesis at the same treatment concentration.We further explored at which stage actein inhibited the adipogenesis of 3T3-L1 preadipocytes.It was found that actein could suppress both differentiation and lipid accumulation stages of adipogenesis.To investigate the effect of actein on diet-induced obesity,we fed 5-week-old C57BL/6 mice on an LFD,HFD,HFD supplemented with 0.001% or 0.005% actein for 12 weeks,respectively.The results showed that actein improved diet-induced obesity and related metabolic disorders.The mechanism of actein improving diet-induced obesity is similar to that of CF and ECF,which can promote lipolysis and browning of adipose tissue and increase energy consumption.In addition,to investigate the effect of actein on pre-established obesity in diet-induced obese(DIO)mice,we fed mice a high-fat diet for 12 weeks and then fed the DIO mice with LFD,LFD with 0.005% actein,HFD or HFD with 0.005% actein for 8 weeks.It was found that for the DIO mice,Actein could also significantly reduce body weight and ameliorate metabolic disorders.Furthermore,mechanistic studies revealed that actein has tissue-specific effects on lipolysis and browning of adipose tissue,which mainly promote browning of subcutaneous adipose tissue(SAT)and lipolysis of epididymal adipose tissue(EAT),respectively.To investigate whether these effects of actein are spontaneous in adipocytes,we isolated stromal vascular fraction cells(SVFs)from WAT and performed coculture experiments using a two-chamber transwell system.It was found that actein can directly promote the transformation of white adipocytes to beige adipocytes by activating the phosphorylation of AMPK,but the effect of actein on lipolysis of adipocytes derived from EAT needs to be mediated by SVFs.The effect of DA on the differentiation process of 3T3-L1 preadipocytes was investigated.It was found that DA,unlike actein,inhibited the adipogenesis of 3T3-L1 preadipocytes mainly at the early stage of differentiation.To examine the effect of DA on diet-induced obesity,we fed 5-week-old C57BL/6 mice on an LFD,HFD,HFD supplemented with 0.001% or 0.005% DA for 12 weeks,respectively.The results revealed that 0.005% DA treatment improved diet-induced obesity and related metabolic disorders.To explore the potential mechanisms by which DA may reduce the HFD-induced obesity in mice,we next examined the expression of genes involved in lipolysis and lipogenesis.Significantly,the m RNA levels of lipolysis-related genes,including Atgl,Hsl,and Perilipin,were all upregulated by dietary DA in adipose tissue.However,DA did not down-regulated the expression of lipogenesis-related genes in adipose tissues in HFD-fed mice.These observations revealed that DA prevents obesity through inhibiting adipogenesis and promoting lipolysis,rather than reducing lipogenesis.We next detected the expression of lipolysis regulatory genes and proteins in adipose tissue.The results suggested that DA activates AMPK signaling and SIRT1-FOXO1 pathway to promote adipose tissue lipolysis in HFD-fed mice.In summary,we found that CF can ameliorate high-fat diet-induced obesity and glucose homeostasis in mice,and elucidated its main active components and mechanism of action.This study provides promising therapies for obesity and associated metabolic diseases,as well as a new theoretical basis for the utilization of CF resources.