Tanshinone IIA affects the HDL subfractions distribution not serum lipid levels: Involving in intake and efflux of cholesterol.

AIM OF STUDY: Tanshinone IIA is an active component of the traditional Chinese medicine. This study aimed at investigating the mechanism of tanshinone IIA on anti-atherosclerosis, which may be because of that Tanshinone IIA can affect the HDL subfractions distribution and then regulate reverse cholesterol transport. MATERIALS AND METHODS: A model of hyperlipidaemia in rats was used. Tanshinone IIA was given daily after hyperlipidaemia. In vivo, lipid deposition and morphological changes in liver were analyzed; HDL subfractions and lipid level in serum as well as in liver were measured; the expression of genes related to cholesterol intake in liver and peritoneal macrophage cholesterol efflux were evaluated. In vitro, HepG2 cells and THP-1 cells were pretreated with tanshinone IIA and subsequently with ox-LDL to evaluate the total cholesterol and the expression of related genes. RESULTS: Tanshinone IIA reduced the lipid deposition in liver. Moreover, it did not affect the serum lipid levels but reduced the levels of HDL middle subfractions and increased the levels of HDL large subfractions. Furthermore, tanshinone IIA could regulate the expressions of CYP7A1, LDL-R, SREBP2 and LCAT in the liver as well as the ABCA1 and CD36 in macrophage cells which is involving in the cholesterol intake and efflux respectively. It could reduce lipid accumulation caused by ox-LDL induction, and that also regulate the expressions of LDL-R, HMGCR and SREBP2 in HepG2 and ABCA1, CD36 in THP-1 cells. CONCLUSION: A novel finding that tanshinone IIA was not reduce the serum lipid level but affects the HDL subfractions distribution and thereby regulating the intake and efflux of cholesterol.

[Intervention of Huayu Qutan Recipe on liver SREBP-2 signal pathway of hyperlipidemia rats of pi deficiency syndrome].

OBJECTIVE: To explore the intervention of Huayu Qutan Recipe (HQR) on liver SREBP-2 signal pathway of hyperlipidemia rats of Pi deficiency syndrome (PDS). METHODS: Totally 100 SPF grade SD rats were randomly divided into the blank control group, the hyperlipidemia group, the hyperlipidemia treatment group, the PDS hyperlipidemia group, and the PDS hyperlipidemia treatment group, 20 in each group. Common granular forage was fed to rats in the blank control group. High fat forage was fed to rats in the hyperlipidemia group and the hyperlipidemia treatment group. Rats in the PDS hyperlipidemia group and the PDS hyperlipidemia treatment group were treated with excessive labor and improper diet for modeling. They were administered refined lard by gastrogavage (3 mL each time, twice per day) and fed with high fat forage on the odd days, and fed with wild cabbage freely on even days. The modeling lasted for 30 days. Rats in the hyperlipidemia treatment group and PDS hyperlipidemia treatment group were administered with Huayu Qutan Recipe (20 mL/kg) by gastrogavage, once a day, for 30 successive days. Levels of serum cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and serum amylase (AMY) were detected by automatic biochemical analyzer. D-xylose excretion rate was determined using phloroglucinol method. Morphological changes of liver and the lipid deposition in liver were observed using HE stain and oil red O stain respectively, mRNA and protein expression levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), cholesterol 7α-hydroxylase 1 (CYP7A1), LDL-R, and sterol regulatory element binding protein-2 (SREBP-2) were detected using real time RT-PCR and Western blotting. RESULTS: Compared with the blank control group, serum levels of TC (1.84 ± 0.19 mmol/L, 2.23 ± 0.43 mmol/L) and LDL-C (0.99 ± 0.24 mmol/L, 1.13 ± 0.56 mmol/L) were higher in the hyperlipidemia group and the PDS hyperlipidemia group, serum levels of HDL-C (0.41 ± 0.66 mmol/L, 0.41 ± 0.11 mmol/L) and AMY activities (351 ± 45 mmol/L, 153 ± 30 mmol/L) were lower, and urinary D-xylose excretion rates were lower (26.9 ± 2.1 ng/mL, 15.0 ± 1.7 ng/mL) (all P < 0.05). Lipid deposition occurred in liver cells. Much fat vacuoles occurred in the cytoplasm. Expression levels of HMGCR, CYP7A1, LDL-R, and SREBP-2 mRNA and proteins in liver significantly decreased (P < 0.01). Compared with the hyperlipidemia group, serum levels of TC and LDL-C significantly increased (P < 0. 05), AMY activities and urinary D-xylose excre- tion rates significantly decreased in the PDS hyperlipidemia group (P < 0.01). A large amount of lipid deposition occurred in liver. The atrophy of liver cells was obviously seen. Expression levels of CYP7A1, LDL-R, and SREBP-2 mRNA and proteins in liver were significantly lower (P < 0.01, P < 0.05). Serum levels of TC and LDL-C significantly decreased (P < 0.05), AMY activities and urinary D-xylose excretion rates significantly increased in the hyperlipidemia treatment group (P < 0.01). Expression levels of CYP7A1, LDL-R, and SREBP-2 mRNA and proteins in liver were significantly increased (P < 0.01, P < 0.05). Compared with the PDS hyperlipidemia group, serum level of TC significantly decreased (P < 0.05), HDL-C levels, AMY activities and urinary D-xylose excretion rates significantly increased in the PDS hyperlipidemia treatment group (P < 0.01),expression levels of CYP7A1, LDL-R, and SREBP-2 mRNA and proteins in liver were significantly increased (P < 0.01). Similar changes occurred in the two treatment groups. CONCLUSIONS: Pi deficiency exacerbates abnormal serum TC level and the lipid deposition in liver. These might be related to regulating expression levels of LDL-R, HMGCR, and CYP7A1 genes in the SREBP-2 signal pathway. HQR could regulate this pathway to intervene abnormal metabolism of TC.