Evaluation of Beneficial and Adverse Effects of a Diet Supplemented with Schisandrae Fructus Seed Ethanol Extract on Lipid and Glucose Metabolism in Normal and Hypercholesterolemic/Hyperglycemic Mice

Abstract

Schisandrae Fructus (SF), the fruit of Schisandra chinensis (Turcz.) Baillon, has been used for the treatment of liver injury and metabolism-related disorders in China. The objective of this study was to investigate the effects of supplementation with ethanol extract of SF seed (EtSF-S) on serum/hepatic lipid and glucose levels as well as fecal total cholesterol (TC) contents in mice fed a normal diet (ND) or high-fat/fructose diet (HFFD) containing 15% lard oil and 15% fructose. Female ICR mice (18-20 g in body weight) were fed with ND or HFFD for 3 months, and then EtSF-S was added to both chow diets at increasing concentrations of 1, 5, and 10% (w/w). Thirty days later, serum and hepatic lipids, including TC, triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and glucose, were measured. Dietary supplementation with EtSF-S reduced hepatic TC (36 and 18%) and TG levels (38 and 28%) and increased serum HDL/LDL ratio (16 and 26%) in both ND- and HFFD-fed mice, respectively. Moreover, supplementation with EtSF-S elevated serum HDL (31%) in HFFD-fed mice and reduced serum LDL (27%) in ND-fed mice. EtSF-S treatment reduced fat mass (40%) in ND-fed mice and increased fecal TC contents (33%) in HFFD-fed mice. EtSF-S supplementation decreased hepatic glucose contents (29%) in both ND- and HFFD-fed mice. However, diet supplemented with EtSF-S elevated serum TG levels (up to 123%) and hepatic size (28%), but more importantly, suppressed the body weight gain (approximately 130%) in mice fed with HFFD. These findings suggested that dietary supplementation with EtSF-S as natural herbal function food may be a useful strategy for the treatment of patients with fatty liver disease or overweight without a high intake of sugar and fat.

Figure 1

The experimental protocol of the present study.

Figure 2

HPLC chromatogram of reference substance (a) and EtSF-S (b). (1) Schisandrol A; (2) schisandrin A; (3) schisandrin B (Sch B).

Figure 3

Effect of dietary supplementation with EtSF-S or FF on serum, hepatic, and fecal lipids in ND- and HFFD-fed mice. Mice were fed with normal diet (ND) or high fructose/fat diet (HFFD) for 3 months. Then, animals were fed with ND or HFFD without and with supplementation with the ethanol extract of Schisandrae Fructus (SF) seed (EtSF-S) or fenofibrate (FF). After 30 days of experiment, serum and hepatic total cholesterol (TC) and triacylglycerol (TG) levels including fecal TC contents were measured. The concentrations of EtSF-S in chow diet were estimated on the basis of crude herbal material (SF seed). Values given are the mean ± SD, with N = 10. ^∗p < 0.05, ^∗∗p < 0.01 vs. ND alone; ^†p < 0.05, ^††p < 0.01 vs. HFFD alone.

Figure 4

The summary of the present study.