Polyphenols From Mallotus peltatus (Geiseler) Mull. Arg. Ameliorates FFA-Induced Hepatic Steatosis in L02 Cells and Reduces Lipid Accumulation in Caenorhabditis elegans

Mallotus peltatus (Geiseler) Mull. Arg. (MPMA) is a specialty plant used to make tea in Hainan Province, China. However, its hypolipidemic activity has been rarely studied. In this study, three polyphenol fractions (MPMAP-1, MPMAP-2, and MPMAP-3) were purified from a 60% ethanol extract of MPMA, and the hypolipidemic activities were evaluated by establishing an FFA-induced L02 cell model to determine lipid accumulation, antioxidant enzyme activities, and gene levels related to the Nrf2/ARE pathway and lipid metabolism. In addition, noninduced and high glucose-induced models were established using Caenorhabditis elegans (C. elegans) to evaluate the lipid-lowering activity of MPMAP-1. The results showed that all three polyphenols could significantly inhibit lipid accumulation, reduce intracellular MDA content, and enhance the activities of CAT, SOD, and GPx in FFA-induced L02 cells. The qRT-PCR results indicated that the amount of fat accumulation in L02 cells could be regulated by modulating the relative expression of mRNA in the Nrf2/ARE signaling pathway and lipid metabolism pathway. The noninduced model and high glucose-induced model demonstrated that MPMAP-1 was able to reduce lipid accumulation and ROS levels and increase the activities of antioxidant enzymes in C. elegans. In summary, our results suggested that polyphenol compounds of MPMA may be a promising natural product for lipid-lowering.