The Study On Genipin Promoting Brown Fat Activation And White Fat Browning In Mice

Objective:To investigate the effects of genipin on promoting brown adipose tissue activation and white adipose tissue browning,and its effects on reducing fat in the obese mice induced by high-fat diet.Methods:1.The Male C57BL/6J mice were divided into three groups: normal control group,genipin group and cold-stimulus group.Genipin group were treated consecutively with genipin at a dose of 15mg/kg.d once a day for 9 days,normal control group were treated with the normal saline.The mice with cold-stimulus were exposed to 4? environment for 5 days.Daily food amount and body weight were measured.The gene and protein expressions of uncoupling protein 1(UCP1)were determined by real time PCR and western blotting respectively.2.The Male C57BL/6J mice were fed high-fat diet for 8 weeks.The obese mice were randomly divided into obese control group(DIO),and medicated groups given by genipin with low(DIO+GL,15 mg/kg.d)and high dose(DIO+GH,30 mg/kg.d).Abovementioned medication groups received daily intraperitoneal injection with genipin according to the prescribed dosage respectively,the normal control group and DIO group received the same volume of saline treatment for 10 days.The body weight,Lee's index,body fat rate and the morphology of adipocytes were measured,and the expressions of browning genes and proteins in adipose tissue were detected by using q PCR and Western blotting.Result:1.Genipin promoted brown adipose tissue activation and white adipose tissue browning by upregulating UCP1 expression.(1)The wet weight of white fat in genipin group and cold-stimulus group decreased significantly compared with normal control group(P<0.05).(2)After treatments of genipin and cold-stimulus,the color of white adipose tissues was darker and the lipid droplets in the adipocytes were smaller,whereas the number increased.(3)Compared with normal control group,UCP1 expression increased obviously in adipose tissues,including brown adipose tissue,the subcutaneous and visceral white adipose tissues after genipin and cold-stimulus(P<0.05).2.Genipin reduced fat and body weight by promoting brown adipose tissue activation and white adipose tissue browning in DIO mice.(1)After high fat diet for 8 weeks,body weight,body fat rate and Lee's index of DIO mice were higher than that of NC mice(P<0.01),but genipin decreased the above quotas at both doses(P<0.01).(2)AUCip GTT,TC and TG of DIO mice were higher than NC mice(P<0.05),whereas they were signficantly ameliorated after genipin treatment(P<0.05).(3)The adipocytes of DIO mice were hypertrophic,in which contained some bigger lipid droplets.After treatments of genipin(low dose or high dose),the lipid droplets in the adipocytes were smaller,whereas the number increased.(4)The expressions of fat browning related genes,including uncoupling protein 1(UCP1),peroxisome proliferator activated receptor coactivator 1?(PGC1?),cell death inducing DFFA-like effector A(CIDEA),PR domain-containing protein 16(PRDM16)in brown,subcutaneous and visceral adipose tissues of DIO mice,was significantly lower than that in NC mice(P<0.05).Compared with DIO mice,the above mentioned browning related genes were obviously increased in adipose tissue,including brown adipose tissue,the subcutaneous and visceral white adipose tissues after genipin treatment at both doses(P<0.05).Conclusions:1.Genipin promoted brown fat activation and white fat browning by upregulating UCP1 expression.2.Genipin could reduce fat and body weight by promoting brown fat activation and white fat browning in DIO mice.