Luteolin ameliorates skin lipid hypersecretion, inflammation and oxidative stress in vivo and in vitro

Luteolin (LUT) is a natural dietary ingredient with a wide range of biological functions and has been used in skin improvement. Skin lipid overproduction is an exceedingly common disorder of the pilosebaceous glands and is popular in adolescents. This study evaluated the effect of LUT on ameliorating oleic acid (OA) induced skin lipid accumulation in C57BL/6 mice and SZ95 cells. The level of major lipids and some key lipid metabolism markers were assessed, including triglyceride (TG), non-esterified fatty acid (NEFA), cholesterol, sterol regulatory-binding protein 1 and peroxisome proliferator-activated receptors. In vivo data showed decreasing significantly cholesterol levels and in vitro data demonstrated the remarkable influence in the reduction of TG and NEFA levels. Besides, LUT affected the diversity and structure of gut bacteria, an increase in the relative abundance of Akkermansia, Bacteroides and Alistipes, which were associated with the anti-oxidative and anti-inflammatory process. Additionally, our study presented that LUT significantly reduced the level of malondialdehyde (MDA, a lipid peroxidation marker), inhibited the expression of pro-inflammatory factor (TNF-α, IL-6) as well as up-regulated the mRNA expression level of SIRT1, indicating LUT alleviating inflammation and enhancing antioxidation may be associated with the activation of SIRT1 pathway.