Researches On The Synergy Of EGCG And Caffeine And The Green Tea Infusion Of Hypolipidemic And Anti-obesity Effect And Mechanism

Obesity has become one of the most widespread chronic diseases in the world.World Health Organization considers it one of the most serious public health problems in the 21 st century mainly because of its high association with many other malignant diseases.Among them,the most closely related is non-alcoholic fatty liver disease(NAFLD).Obesity is the most prominent feature of NAFLD and plays a pivotal role.There have been many attempts at obesity treatments in the past,but it turns out that the phytotherapy including green tea is the best option.However,recent studies have found that high-dose epigallocatechin gallate(EGCG)has hepatotoxicity.Besides,there are other limitations such as inconsistency between literature reports and actual intake.Hence,it is a research hotspot and a realistic demand depending on green tea therapy in a more scientific and effective way.This study demonstrated that the low dose EGCG and caffeine has the synergistic effect on the amelioration of obesity and NAFLD.Previous studies have shown that EGCG or caffeine could loss weight.However,high doses of EGCG are commonly used in previous studies for ensuring the effect,and the unsafety of this approach has been frequently reported in recent studies.In this study,we fed high-fat diet for obesity modeling,then sufficiently obese rats were selected for next administration(therapeutic experiment): 40 mg/kg EGCG,20 mg/kg caffeine and a combination of them,which was similar to the daily intake.Besides,160 mg/kg EGCG,as a high dose,is the maximum safe dose which has reached the controversial edge in the current literature.The results showed that the coadministration of EGCG and caffeine was better than the combination alone in inhibiting weight gain,reducing white adipose tissue weight and reducing energy intake.This may be caused by the blood lipids down-regulation,oxidative stress recovering,and the levels of fatty and inflammatory cytokine proteins changes.The most intuitional pathological micrograph showed that long-term high-fat diet would lead to considerable NAFLD.However,all groups improved at different levels of administration,but the high-dose EGCG group was no better than the low-dose EGCG or caffeine group,and the combination of low-dose EGCG and caffeine improved significantly.To sum up,low-dose EGCG or caffeine has a mild effect on the improvement of obesity and NAFLD.The synergistic effect of the combination progressively improves the efficacy without safety anxiety.This study also demonstrated that green tea infusions and its dietary supplements could effectively prevent obesity and NAFLD in rats.There are three main types of green tea consumption: green tea beverage includes natural brewed green tea infusion(GTI)and decoction(GTD);Green tea dietary supplements mainly includes caffeinated tea polyphenols(CGTP)and decaffeinated tea polyphenols(DCGTP).And green tea extract(GTE)is in between.These methods will be researched in the same low dose to compare the efficacy and elucidate the mechanism.Compared with the Normal diet(ND)group,the Obesity(OB)group was significantly affected by the high fat diet.The results of treatment for 56 days(Preventive experiment)showed that each treatment group variously reduced the weight of body and adipose tissue;and regulated the levels of TC,TG,LDL-c,HDL-c,ALT and AST in serum;The oxidative stress state was improved,and the enzyme activities of SOD,CAT,GSH-Px and GSH content in liver were increased.Quantitatively decreased LEP and increased APN expression in adipocytes.At the molecular level,the mRNA expression levels of FAS was decreased,and CPT-1a,MCD and LDLR were increased.The protein expression levels of SREBP1 was reduced and AMPK was increased.Microscopic observations showed reduced lipid accumulation,ballooning,and lobular inflammation.But overall,the GTD and CGTP groups performed slightly better than the GTI,DCGTP,and GTE groups.Therefore,this paper has been proved that green tea drinking on a daily basis can have similar efficacy as taking dietary supplements,and both of them are the safe and effective phytotherapy about weight loss.Since then,this paper has comprehensively and systematically studied the effect of green tea on reducing fat and losing weight and elucidated the mechanism from green tea to single functional component.The full text links up a chain of green tea’s functional components--from the basic green tea infusion to the crude extract,to the tea polyphenols,to the highly purified EGCG and caffeine.In general,these results showed that even the target of action is not consistent,no matter the form of green tea functional ingredients intake,all of them with daily dose could lose weight effectively and concernedly.