Inhibition of hepatitis C virus replication by Monascus pigment derivatives that interfere with viral RNA polymerase activity and the mevalonate biosynthesis pathway.

OBJECTIVES: Hepatitis C virus (HCV) infection causes chronic liver disease and is a major public health problem worldwide. The aim of this study was to evaluate the potential of Monascus pigment derivatives, which were derived from a microbial secondary metabolite synthesized from polyketides by Monascus spp., as HCV antiviral agents. METHODS: We performed an in vitro RNA-dependent RNA polymerase (RdRp) assay to screen for HCV RdRp inhibitors. The anti-HCV activity of RdRp inhibitors in HCV-replicating cells was evaluated by quantification of the RNA viral genome. Molecular docking analysis was performed to predict the binding sites of the selected RdRp inhibitors. RESULTS: We have identified a Monascus pigment and its derivatives as inhibitors of the HCV NS5B RdRp. A group of Monascus orange pigment (MOP) amino acid derivatives, in which the reactive oxygen moiety was changed to amino acids, significantly inhibited HCV replication. Further, combination of the MOP derivatives (Phe, Val or Leu conjugates) with interferon (IFN)-α inhibited HCV replication more than IFN-α treatment alone. Lastly, molecular docking studies indicate the inhibitors may bind to a thumb subdomain allosteric site of NS5B. The antiviral activity of the MOP derivatives was related to a modulation of the mevalonate pathway, since the mevalonate-induced increase in HCV replication was suppressed by the MOP compounds. CONCLUSIONS: Our results identify amino acid derivatives of MOP as potential anti-HCV agents and suggest that their combination with IFN-α might offer an alternative strategy for the control of HCV replication.

Dietary hempseed meal intake increases body growth and shortens the larval stage via the upregulation of cell growth and sterol levels in Drosophila melanogaster.

Hempseed, a rich source of polyunsaturated fatty acids (PUFAs) and phytosterols, has been recognized as a potential therapeutic food used for cardioprotection, preventing platelet aggregation, and improving atopic dermatitis. Although several studies have revealed the physiological benefits of hempseed on a variety of animals, the effects of dietary hempseed intake on animal development are currently unknown. In this study, we evaluated the developmental effects of the addition of hempseed meal (HSM) to the diet of Drosophila. Interestingly, dietary HSM intake was shown to increase the body size of flies by increasing cell numbers, and also truncated the larval period without affecting survival rate or longevity. The oviposition of female flies was also increased by dietary HSM supplementation. Interestingly, the levels of sterols, which are precursors of ecdysone, a molting hormone, were found to be elevated in the larvae fed on HSM. Additionally, the hexane extracts of hempseed mimicked the effects of HSM on growth, developmental timing, and reproduction. Moreover, among the major nonpolar components of HSM, feeding on cholesterol but not PUFA mix or campesterol accelerated pupariation and increased body size. These results indicate that the dietary intake of HSM accelerates both body growth and developmental rates in Drosophila via the stimulation of cell growth and ecdysone synthesis. Additionally, nonpolar components of hempseed, such as cholesterol, might be responsible for the effects of HSM on development and reproduction.

Toxicological evaluation of fucoidan from Undaria pinnatifidain vitro and in vivo.

The potential toxicity of fucoidan from Undaria pinnatifida was investigated in vitro and in vivo. By the Ames test, fucoidan showed no mutagenicity up to 500 microL/plate, and inhibited the mutagenicity induced by 4-nitro-quinoline-1-oxide, by up to 71%, compared with controls. In the bone marrow micronucleus test, fucoidan, at all levels tested, did not change the micronucleated polychromatic erythrocyte percentage ratio in mouse bone marrow cells. As an acute in vivo toxicity test, fucoidan from 0 to 2000 mg/kg body weight per day was administered orally to Sprague-Dawley rats for 28 days. No significant toxicological change was induced by fucoidan treatment up to 1000 mg/kg body weight per day in biochemical analyses, hematological analyses, necropsy and liver histopathology. The plasma ALT level was slightly, but significantly, increased in male rats at 2000 mg/kg/day. The consumption of fucoidan from Undaria pinnatifida, up to 1000 mg/kg body weight per day, may be safe in rodents, with no sign of toxicity after up to 28 days of daily administration.

L-Trp and L-Leu-OEt derivatives of the monascus pigment exert high anti-obesity effects on mice.

High-fat diets (HFDs) supplemented with the L-Trp and L-Leu-OEt derivatives of the monascus pigment were fed to mice. Compared to the HFD group, the average body weight gain of the four HFD-pigment groups was decreased by 13.6-50.9%, and the intra-peritoneal adipose tissues weight was reduced by 16.7-30.5%. The derivatives also reduced the respective serum total cholesterol and triglyceride levels of the mice by 9.7-14.4% and 12.5-17.2%. The L-Trp derivative greatly increased the HDL-cholesterol level by 64.8-66.4% and the HTR value by 73.8-81.7%. The L-Leu-OEt and L-Trp derivatives decreased the total cholesterol level in the mice liver by 9.7-24.2% and 36.2-39.9%, respectively. Reductions in the triglyceride level were 21.5-22.4% for the L-Leu-OEt derivative and 17.9-18.8% for the L-Trp derivative. The L-Leu-OEt derivative exhibited higher in vitro inhibitory activities against HMG-CoA reductase and lipoprotein lipase than the L-Trp derivative. An in vivo test with mice showed the L-Trp derivative to have higher anti-obesity effects than the L-Leu-OEt derivative.

Hypocholesterolemic effects of Lactobacillus plantarum KCTC3928 by increased bile acid excretion in C57BL/6 mice.

OBJECTIVE: We doubly coated Lactobacillus plantarum KCTC3928 with proteins and polysaccharide compounds to enhance its acid and bile resistance. The present study investigated the hypocholesterolemic effects of double-coated L. plantarum KCTC3928 in C57BL/6 mice fed a high-fat diet. The effects of live and dead bacteria were compared. METHODS: Six-week-old C57BL/6 male mice were divided into three groups: the control group was fed no L. plantarum KCTC3928, and the two treatment groups were orally fed live or dead L. plantarum KCTC3928 daily. Plasma and liver cholesterol and lipid levels, fecal bile acid, and gene and protein expressions were measured. RESULTS: Low-density lipoprotein cholesterol and plasma triacylglycerol levels were significantly lower in the group fed live bacteria, by 42% and 32%, respectively (P<0.05), and fecal bile acid excretion was accelerated (+45%). Expression of the low-density lipoprotein receptor and 3-hydroxy-3-methylglutaryl coenzyme A reductase were marginally affected by the feeding of coated cells; however, the gene expression and protein levels of CYP7A1 were significantly upregulated after live L. plantarum KCTC3928 feeding (+80% for mRNA and +60% for protein expression). CONCLUSION: Double-coated live L. plantarum KCTC3928 may have hypocholesterolemic effects in mice primarily due to induction of fecal bile acid secretion followed by increased degradation of hepatic cholesterol into bile acids. Studies in humans should confirm the effects in the future.