Preadipocytes under nutrient excess mature to lipid-laden adipocytes that are hotspots for generation of reactive oxygen species (ROS) imbalance and oxidative stress. Syringic acid (SA), a natural phenolic acid, was evaluated for its in vitro antioxidant and ROS modulation during in matured 3T3-L1 adipocytes. Following 10 d, the SA-treated adipocytes were evaluated for the levels of glutathione (GSH) and antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT). The levels of peroxides in mature adipocytes were estimated using dichlorofluorescein (DCF) cleavage fluorescence. The level of NADPH oxidase 4 (NOX4) expression was also investigated following 10-d differentiation period. SA significantly improved the levels of GSH, SOD, and CAT in matured adipocytes. Reduction in ROS production levels was also witnessed by decrease in DCF cleavage. SA showed concentration-dependent inhibition of NOX4 by day 7 of adipogenesis when compared with differentiated and undifferentiated cells. Moreover, SA exhibited effective antioxidant and anti-radical scavenging activity. These results suggest that SA in addition to inhibiting adipogenesis can strongly reduce ROS stress in mature adipocytes by upregulating levels of intracellular antioxidants and decreasing levels of NOX4 in 3T3-L1 adipocytes.

Graphical abstract

中文翻译：

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3,5-二甲氧基-4-苯甲酸（丁香酸）是一种天然酚酸，可减少分化的 3T3-L1 脂肪细胞中的活性氧

营养过剩的前脂肪细胞成熟为富含脂质的脂肪细胞，这些脂肪细胞是产生活性氧 (ROS) 失衡和氧化应激的热点。丁香酸 (SA) 是一种天然酚酸，在成熟的 3T3-L1 脂肪细胞中对其体外抗氧化和 ROS 调节进行了评估。10 天后，评估 SA 处理的脂肪细胞的谷胱甘肽 (GSH) 和抗氧化酶如超氧化物歧化酶 (SOD) 和过氧化氢酶 (CAT) 的水平。使用二氯荧光素 (DCF) 裂解荧光估计成熟脂肪细胞中过氧化物的水平。在 10 天分化期后还研究了 NADPH 氧化酶 4 (NOX4) 的表达水平。SA 显着提高成熟脂肪细胞中 GSH、SOD 和 CAT 的水平。DCF 裂解的减少也见证了 ROS 产生水平的降低。与分化和未分化细胞相比，SA 在脂肪生成的第 7 天显示出浓度依赖性的 NOX4 抑制。此外，SA 表现出有效的抗氧化和抗自由基清除活性。这些结果表明，SA 除了抑制脂肪生成外，还可以通过上调细胞内抗氧化剂的水平和降低 3T3-L1 脂肪细胞中 NOX4 的水平来强烈降低成熟脂肪细胞中的 ROS 应激。

图形概要