Dietary pulp from Fructus Schisandra Chinensis supplementation reduces serum/hepatic lipid and hepatic glucose levels in mice fed a normal or high cholesterol/bile salt diet

Background: Recently, it has been found that Fructus Schisandra Chinensis (FSC), a Chinese herbal medicine, and its related compounds have a profound impact on lipid metabolism process. FSC can be divided into two parts, i.e., seed and pulp. The current study aimed to examine the effect of aqueous extracts of FSC pulp (AqFSC-P) on serum/hepatic lipid and glucose levels in mice fed with a normal diet (ND) or a high cholesterol/bile salt diet (HCBD). Methods. The AqFSC-P used in the present study was fractionated into supernatant (SAqFSC-P) and precipitate (PAqFSC-P) separated by centrifugation. Male ICR mice were fed with ND or HCBD, without or with supplementation of 1%, 3%, or 9% (w/w) SAqFSC-P or PAqFSC-P for 10 days. Biomarkers were determined according to the manufacturer's instruction. Results: Supplementation with SAqFSC-P or PAqFSC-P significantly reduced serum and hepatic triglyceride levels (approximately 40%) in ND- and/or HCBD-fed mice. The supplementation with SAqFSC-P or PAqFSC-P reduced hepatic total cholesterol levels (by 27 - 46%) in HCBD-fed mice. Supplementation with SAqFSC-P or PAqFSC-P markedly lowered hepatic glucose levels (by 13 - 30%) in ND- and HCBD-fed mice. SAqFSC-P decreased serum alanine aminotransferase (ALT) activity, but PAqFSC-P increased hepatic protein contents in ND-fed mice. Bicylol, as a positive control, reduced ALT activity. In addition, mice supplemented with FSC-P or bicylol showed a smaller body weight gain and adipose tissue mass as compared to the respective un-supplemented ND- or HCBD-fed mice. Conclusion: The results indicate that SAqFSC-P and PAqFSC-P produce hepatic lipid- and glucose-lowering as well as serum TG-lowering effects in hypercholesterolemic mice. FSC pulp may provide a safe alternative for the management of fatty liver and/or lipid disorders in humans.