Differential Effects of Red Yeast Rice, Berberis Aristata and Morus Alba Extracts, Active Components of LopiGLIK®, on PCSK9 in HepG2 Cells

Abstract

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is the key regulator of low-density lipoprotein cholesterol (LDL-C) plasma levels. We previously observed that treatment of dyslipidemic subjects with nutraceutical combination containing red yeast rice (monacolin K 3.3 mg), Berberis aristata cortex extract (Berberine 531.25 mg) and Morus alba leaves extract (1-deoxynojirimycin 4 mg) (LopiGLIK®) did not alter the plasma PCSK9 levels. Thus, the aim of the present study was to investigate the effect of these three components on PCSK9 expression in HepG2 cell line in relationship to their effects on LDL-C cellular uptake. HepG2 cell line were incubated with Berberis aristata cortex extract (BCE), red yeast rice (RYR) and Morus alba leaves extract (MLE) alone or in combination for 24 h. RYR (50 µg/mL) increased PCSK9 protein expression (WB and ELISA assays), PCSK9 mRNA and its promoter activity. BCE (40 µg/mL) reduced PCSK9 expression, mRNA levels and promoter activity. MLE determined a concentration-dependent inhibition of PCSK9 at mRNA and protein levels, with a maximal reduction at 1 mg/mL; no significant changes in PCSK9 promoter activity were found. MLE also downregulates the expression of fatty acid synthase and HMG-CoA reductase mRNA levels. The combination of RYR, BCE and MLE reduced PCSK9 at mRNA, protein, and promoter activity. Finally, this combination induced the LDL receptor and LDL-C uptake by HepG2 cells. In conclusion, the positive effect of MLE on PCSK9 supports the rational of using this nutraceutical combination to control hyperlipidemic conditions.

The Activity of Ten Natural Extracts Combined in a Unique Blend to Maintain Cholesterol Homeostasis—In Vitro Model

“…Firstly, to evaluate the effects on HepG2 cells leading to finding the non-toxic concentration, a dose–response study was performed, testing the extracts in a range reported in the literature. Indeed, the cells were treated with increasing concentrations of sage extract (from 0.029 to 0.3 µM) [ 12 ], Red Yeast Rice (RYR, from 1 to 50 µM) [ 10 ], Vitamin D3 (from 1 to 100 nM) [ 38 ], Resveratrol (from 1 to 40 µM) [ 39 ], Quercetin (from 5 to 10 µM) [ 40 ], Astaxanthin (from 1.7 to 17 nM) [ 41 ], CoQ10 (from 1 to 100 µM) [ 42 ], Vitamin K2 (from 0.01 to 1 µM) [ 43 ], Sodium Selenite (from 1 to 10 µM) [ 44 ], Folic Acid (from 25 to 75 µg/mL) [ 45 ]. The best concentration of each extract was maintained for all successive experiments.…”

“…For example, it is suggested that polyphenolic compounds can be used to activate AMPK to reduce oxidative damage and inflammation, which play a critical role in the development of chronic disease [ 9 ]. In nature, several nutraceutical combinations have shown significant lipid-lowering effects and a potential positive impact on cardiovascular risk by modulating the proprotein convertase subtilisin/kexin type 9 (PCSK9) factor which plays a particular role in regulating LDL-C levels by degrading the LDL receptor (LDLr) [ 10 ]. Based on all these results it is important to resolve the claim about some nutraceuticals with RYR by studying the combined effects of several active ingredients, such as Sage extract, Resveratrol, Folic Acid, vitamin D3, Quercetin, Astaxanthin, and CoQ10.…”