Research Into Mechanism Of Capsaicin On Cholesterol Metabolic In Vivo

Capsaicin as raw materials in this study, mechanism of capsaicin on cholesterol metabolic in rats was researched by chemical analysis, instrument analysis and animal experiment which provide basic theoretical for food processing and food health. The main conclusions of the research are as follows:(1) In this study, thirty-three female and male SD rats were randomly allocated to four groups after adapted feeding one week:control group(n=8), low-dose group (n=8), middle-dose group(n=8), high-dose group(n=8), fed the same basic diet for 28 days and gavaged 0,2.5,5.0,7.5 mg/kg/d capsaicin respectively. Testing indicators:body-weight gaining was decreased by capsaicin, but not in feed efficiency. There was gender difference in the decreasing of total cholesterol of plasma and liver by capsaicin, sensitivity of female rats were higher than male. Liver weight, liver fat weight, hepatic total cholesterol(TC) and triacylglycerol(TG) were decreased by capsaicin. The level of transient receptor potential vanilloid-1(TRPV1) mRNA in liver was increased by the high-dose capsaicin, as well as the level of sodium-dependent bile salt transporter (ASBT) and ileum bile acid binding protein(IBABP) mRNA in ileum(P<0.05). The level of cholesterol 7a-hydroxylase (CYP7A1), farnesoid X receptor(FXR) and 3-hydroxy-3-methylglutaryl coenzyme A(HMG-CoA) mRNA in liver were decreased by capsaicin(P<0.05). The experiment proves that gavaging high-dose capsaicin daily has a good effect in stimulating appetite, decreasing serum lipids and hepatic lipids, regulating cholesterol metabolism cycle in rats. Capsaicin affects cholesterol metabolism by increasing the level of hepatic cholesterol metabolism genes and decreasing the level of ileum bile metabolism genes to decrease the cholesterol in plasma and liver.(2) Animal model was established by simulating the menopausal women. Thirty female SD rats were allocated to five groups randomly after ovariectomizing(OVX) and sham ovariectomizing: sham group(n=6), control group(n=6), low-dose group (n=6), middle-dose group(n=8), high-dose group(n=8), fed the same basic diet for 28 days and gavaged 0,0,5.0,10.0,15.0mg/kg capsaicin daily. Testing indicators:the body weight, feed intake, serum lipids, liver fat, hepatic total cholesterol, hepatic triglyceride of control group compared with sham group were significantly higher, which proved the success of this experiment which simulated an animal model of menopausal women. Body-weight gaining, feed intake, plasma cholesterol and fat, total cholesterol, triacylglycerol of liver were decreased by capsaicin, but not in feed efficiency. The level of TRPV1 mRNA in liver was increased by capsaicin, as well as the level of ASBT and IBABP mRNA in ileum(P<0.05). The level of CYP7A1, FXR and HMG-CoA mRNA in liver were decreased by capsaicin(P<0.05). The experiment proves that capsaicin has a good effect in decreasing serum lipids and hepatic lipids, regulating cholesterol metabolism cycle in hyperlipidemia female rats caused by lacking of estrogen, can be effective in preventing hyperlipidemia female rats caused by lacking of estrogen. Capsaicin affects cholesterol metabolism of hyperlipidemia female rats by increasing the level of hepatic cholesterol metabolism genes and decreasing the level of ileum bile metabolism genes to decrease the cholesterol in plasma and liver.(3)Forty-eight male and female SD rats, allocated to six groups randomly, feed basic diet(BD, n=8), high(30%)-fat diet(HFD, n=8) and high(2%)-cholesterol diet(HCD, n=8) with or without gavaging 10mg/kg/d capsaicin.Compared to BD group rats, the serum lipids and hepatic lipid of HFD group rats were significantly higher, so as the liver weight. The level of TRPV1, HMG-CoA mRNA in liver were decreased, but increased in CYP7A1 and FXR, the level of FXR mRNA in female rats had no significant change, but had increased trend. The level of TRPVl mRNA in rats ileum was increased compared to BD group rats, but decreased in ASBT and IBABP. Capsaicin could decrease serum lipids and hepatic lipids of HFD group rats. Capsaicin could increase the level of TRPV1 mRNA in male rats liver, but decrease in FXR and CYP7A1, no significant change in HMG-CoA, but had decreased trend. Capsaicin could increase the level of TRPV1 mRNA in female rats liver, decrease in FXR, HMG-CoA and CYP7A1. The level of TRPV1、ASBT and IBABP mRNA in rats ileum were increased by capsaicin.Compared to BD group rats, the serum lipids and hepatic lipids of HCD group rats were increased, as well as the liver weight, The level of TRPV1, HMG-CoA in liver and ASBT, IBABP in ileum mRNA were decreased, but increased in FXR, CYP7A1 of liver and TRPV1 mRNA of ileum in female rats, and no changes in TRPV1 of ileum in male rats. Capsaicin could decrease the serum lipids, hepatic lipids and the level of FXR, HMG-CoA, CYP7A1 mRNA in liver, increase the level of TRPV1 in liver and TRPV1, ASBT, IBABP mRNA in ileum.The experiment proves that capsaicin has a good effect in decreasing serum lipids and hepatic lipids, regulating cholesterol metabolism cycle in rats which were fed by HFD and HCD. Visible, capsaicin can be effective in preventing hyperlipidemia caused by HFD and HCD. Capsaicin affects cholesterol metabolism of hyperlipidemia rats by increasing the level of hepatic cholesterol metabolism genes and decreasing the level of ileum bile metabolism genes to decrease the cholesterol in plasma and liver.