3-methylquercetin and Fatty-Liver

To investigate the potential effect of Ginkgo biloba extract (GBE) on the prevention and treatment of nonalcoholic fatty liver disease (NAFLD).. Male Wistar rats were divided into 4 groups (the control group, GBE group, high-fat diet [HFD] group and HFD + GBE group). The human hepatocellular carcinoma cell line (HepG2) was treated with GBE and its flavonoid ingredients. The fatty acid composition of the rat liver was analyzed with gas chromatography/time-of-flight mass spectrometry (GC/TOFMS). Triglyceride contents of both the rat liver and HepG2 cells were measured by enzymatic colorimetric method. The expressions of fatty acid metabolism-related genes were analyzed with real-time reverse transcription-polymerase chain reaction (RT-PCR). The protein expression and enzymatic activity were subsequently measured.. In rat livers, GBE reduced the elevations of hepatic triglyceride contents caused by HFD and the increased hepatic fatty acids were differentially affected by GBE. Notably, the expression and total activity of the fatty acid β-oxidation rate-limiting enzyme, carnitine palmitoyltransferase 1a (CPT1A), were also promoted with GBE ingestion. In HepG2 cells, GBE and its ingredients, quercetin, kaempferol and isorhamnetin, could decrease the cellular triglyceride content and upregulate the expression and total activity of CPT1A, respectively.. The triglyceride-lowering effect of GBE on the HFD rat liver is closely associated with the increased expression and activity of CPT1A, and the flavonoid ingredients are the major contributors of GBE.

Topics: Animals; Carnitine O-Palmitoyltransferase; Dietary Fats; Fatty Acids; Fatty Liver; Gene Expression Regulation, Enzymologic; Ginkgo biloba; Hep G2 Cells; Humans; Kaempferols; Male; Non-alcoholic Fatty Liver Disease; Phytotherapy; Plant Extracts; Quercetin; Rats; Rats, Wistar; Triglycerides; Up-Regulation

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease and its incidence is rising worldwide. We compared the antioxidant capacity of seventeen flavonoids with their inhibitory effects on oleic acid-induced triglyceride (TG) over-accumulation in HepG2 cells. The results showed significant correlations (P < 0.01) between the inhibition of intracellular TG levels and the suppression effects on reactive oxygen species. Nevertheless, the radical-reducing activities of flavonoids assessed by chemical assays (cyclic voltammetry and Folin-Ciocalteu reagent assay) were poorly correlated with their intracellular TG inhibitory effects. The relationships between structural properties of flavonoids and their inhibitory effects on TG over-accumulation were discussed.

Topics: Antioxidants; Cell Line; Fatty Liver; Flavonoids; Humans; In Vitro Techniques; Oleic Acid; Reactive Oxygen Species; Triglycerides