Ghanya Al-Naqeep1, Maznah Ismail, Zeenathul Allaudin. 1. Nutraceuticals and Nutrigenomics Programme, Laboratory of Molecular Biomedicine, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Malaysia.
Abstract
BACKGROUND AND AIM: Nigella sativa and its active constituent thymoquinone (TQ) have been exploited for their various health benefits. This work was aimed to investigate the regulatory effects of TQ-rich fraction (TQRF) and commercial TQ on the low-density lipoprotein receptor (LDLR) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) genes in HepG2 cells. METHODS AND RESULTS: TQRF was extracted from N. sativa seeds using supercritical fluid extraction. The regulatory effects of TQRF at 80 microg/ml and TQ at 2 microg/ml on LDLR and HMGCR gene expression were investigated in HepG2 cells using quantitative real-time PCR. The TQ content in TQRF was 2.77% (w/w) and was obtained at a temperature of 40 degrees C and a pressure of 600 bar. Treatment of cells with TQRF and TQ resulted in a 7- and 2-fold upregulation of LDLR mRNA level, respectively, compared with untreated cells. The mRNA level of HMGCR was downregulated by 71 and 12%, respectively, compared with untreated cells. CONCLUSION: TQRF and TQ regulated genes involved in cholesterol metabolism by two mechanisms, the uptake of low-density lipoprotein cholesterol via the upregulation of the LDLR gene and inhibition of cholesterol synthesis via the suppression of the HMGCR gene. Copyright 2009 S. Karger AG, Basel.
BACKGROUND AND AIM: Nigella sativa and its active constituent thymoquinone (TQ) have been exploited for their various health benefits. This work was aimed to investigate the regulatory effects of TQ-rich fraction (TQRF) and commercial TQ on the low-density lipoprotein receptor (LDLR) and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) genes in HepG2 cells. METHODS AND RESULTS: TQRF was extracted from N. sativa seeds using supercritical fluid extraction. The regulatory effects of TQRF at 80 microg/ml and TQ at 2 microg/ml on LDLR and HMGCR gene expression were investigated in HepG2 cells using quantitative real-time PCR. The TQ content in TQRF was 2.77% (w/w) and was obtained at a temperature of 40 degrees C and a pressure of 600 bar. Treatment of cells with TQRF and TQ resulted in a 7- and 2-fold upregulation of LDLR mRNA level, respectively, compared with untreated cells. The mRNA level of HMGCR was downregulated by 71 and 12%, respectively, compared with untreated cells. CONCLUSION: TQRF and TQ regulated genes involved in cholesterol metabolism by two mechanisms, the uptake of low-density lipoprotein cholesterol via the upregulation of the LDLR gene and inhibition of cholesterol synthesis via the suppression of the HMGCR gene. Copyright 2009 S. Karger AG, Basel.
Authors: Sanjeev Banerjee; Subhash Padhye; Asfar Azmi; Zhiwei Wang; Philip A Philip; Omer Kucuk; Fazlul H Sarkar; Ramzi M Mohammad Journal: Nutr Cancer Date: 2010 Impact factor: 2.900