Combination of berberine and evodiamine inhibits intestinal cholesterol absorption in high fat diet induced hyperlipidemic rats

Abstract

Background: Hyperlipidemia characterized of elevated serum lipid levels is a prevalent disease frequently resulting in cardiovascular disease (CVD). Berberine and evodiamine are herbal products of traditional Chinese herb Coptis chinensis and Evodia rutaecarpa, which are indicated to exert regulation of lipid metabolism. Therefore, the objective of this study was to investigate the lipid-lowering effect of berberine and evodiamine combination in hyperlipidemic rats.

Method: The rat model of hyperlipidemia was established by providing high-fat-diet (HFD) for 4 weeks. Berberine (BB), evodiamine (EV), and their combination (BB + EV) were orally administered to HFD induced rats for 4 weeks. Body weight, food utilization, histopathology of liver tissues, lipid profiles of serum and liver were measured. Gas chromatography (GC) analysis was applied to examine the level of plasma total cholesterol and ß- Sitosterol (BS) to estimate cholesterol absorption activity. Furthermore, intestinal NPC1L1, ACAT2, and ApoB48 protein expressions were evaluated by immunohistochemical assay.

Result: According to the results, decreased levels of serum cholesterol (TC), triglycerides (TG), low density lipoprotein-cholesterol (LDL-C), as well as hepatic TC were showed in hyperlipidemic rats treated by combination of berberine and evodiamine. GC analysis indicated that the elevated plasma BS was significantly ameliorated by BB, EV, and BB + EV. In addition, immunohistochemical analysis revealed that BB + EV treatment down-regulated the expressions of intestinal NPC1L1 and ACAT2, and ApoB48 in HFD induced rats.

Conclusion: Based on the above results, combination of berberine and evodiamine exerted a promising preventive effect on hyperlipidemia, partially through inhibiting intestinal absorption of cholesterol.

Keywords: ACAT2; ApoB48; Berberine; Cholesterol absorption; Evodiamine; Hyperlipidemia; NPC1L1.

Fig. 1

Body weights (a) and food intake (b) of each group in week 0, 2, 4, 6, and 8; liver weight index (liver weight/body weight) (c) of each group in week 8. Data are represented as mean ± SD with 10 samples each group. *P < 0.05,**P < 0.01 compared with Control; #P < 0.05,##P < 0.01 compared with Model (ANOVA with Dunnett’s post-hoc test)

Fig. 2

Serum TC (a), serum TG (b), serum LDL-C (c), and serum HDL-C (d) in hyperlipidemic rats in week 4. Data are represented as mean ± SD with 10 samples each group. *P < 0.05,**P < 0.01 compared with Control; #P < 0.05,##P < 0.01 compared with Model (ANOVA with Dunnett’s post-hoc test)

Fig. 3

Serum TC (a), serum TG (b), serum LDL-C (c), and serum HDL-C (d) in hyperlipidemic rats in week 8. Data are represented as mean ± SD with 10 samples each group. *P < 0.05,**P < 0.01 compared with Control; #P < 0.05,##P < 0.01 compared with Model (ANOVA with Dunnett’s post-hoc test)

Fig. 4

Hepatic TC (a) and hepatic TG (b) content of hyperlipidemic rat in week 8. Data are represented as mean ± SD with 10 samples each group. *P < 0.05,**P < 0.01 compared with Control; #P < 0.05,##P < 0.01 compared with Model (ANOVA with Dunnett’s post-hoc test)

Fig. 5

Effect of berberine and evodiamine co-administration on the pathology of liver tissues in hyperlipidemic rats. Specimens were photographed by light microscopy. (H and E staining, magnification: ×400, n = 6)

Fig. 6

Serum total cholesterol (a), serum sistosterol (b), and the ratio of sistosterol by cholesterol (c) measured by gas chromatography in hyperlipidemic rat. Data are represented as mean ± SD with 10 samples each group. *P < 0.05,**P < 0.01 compared with Control; #P < 0.05,##P < 0.01 compared with Model (ANOVA with Dunnett’s post-hoc test)

Fig. 7

Integrated optical density (IOD) of NPC1L1(a), ACAT2 (b), and ApoB48 (c) in HFD induced hyperlipidemic rats (n = 6, mean ± SD). *P < 0.05,**P < 0.01 compared with Control; #P < 0.05,##P < 0.01 compared with Model (ANOVA with Dunnett’s post-hoc test). Histopathological examination of NPC1L1 (d), ACAT2 (e), and ApoB48 (f) in intestine tissue of hyperlipidemic rats in different experiment groups (×400 magnifications, n = 6)