Amentoflavone protects against high fat-induced metabolic dysfunction: Possible role of the regulation of adipogenic differentiation

Abstract

In the present study, we evaluated the protective effects of amentoflavone (AMF) against high-fat (HF) diet-induced metabolic dysfunction and focused on the influence of AMF on adipogenic differentiation during 3T3-L1 adipocyte differentiation. For this purpose, male Wistar rats were fed a HF diet or a HF diet with AMF (10 or 50 mg/kg). We found that AMF protected against HF diet-induced metabolic dysfunction in a dose-dependent manner, as evidenced by a decrease in the fasting blood glucose levels, fasting insulin levels and the homeostatic model assessment-insulin resistance index (HOMA-IR), as well as by a decrease in the glucose level, as shown by the intraperitoneal glucose tolerance test and intraperitoneal insulin tolerance test. Moreover, the results revealed that AMF significantly inhibited the increase in body weight, the weight of perirenal adipose tissues and the serum triglyceride (TG) content of the rats fed the HF diet in a dose-dependent manner. AMF also inhibited the accumulation of oil droplets in differentiated 3T3-L1 adipocytes in a concentration-dependent manner. The incubation of the cells with AMF for 0–8, 0–2, 2–4, or 4–8 days markedly inhibited adipogenesis. During the early phase of the adipocyte differentiation of 3T3-L1 cells, AMF decreased CCAAT/enhancer-binding protein (C/EBP) β expression in a concentration-dependent manner, leading to the inhibition of mitotic clonal expansion (MCE). Moreover, our results demonstrated that AMF significantly increased reactive oxygen species (ROS) generation in the cells and the antioxidant, N-acetylcysteine (NAC), markedly attenuated the inhibitory effects of AMF on adipogenesis. AMF also inhibited the expression of peroxisome proliferator-activated receptor γ (PPARγ) and C/EBPα and the expression of downstream targets in a concentration-dependent manner. The overexpression of PPARγ and C/EBPα (by transfection with respective overexpression plasmids) attentuated the inhibitory effects of AMF on the formation of oil droplets. The inhibitory effects of AMF on adipocyte differentiation may contribute to its protective effects against HF diet-induced metabolic dysfunction. Overall, the data in our study provide novel insight into the mechanisms responsible for the protective effects of AMF against HF diet-induced metabolic dysfunction and those for its inhibitory effect on adipocyte differentiation.

N-Acetylcysteine Inhibits Lipids Production in Mature Adipocytes through the Inhibition of Peroxisome Proliferator-Activated Receptor 

“…We observed that NAC inhibited phosphorylation of mitogen-activated protein kinases in cell cultures [7,16] on the first day of differentiation protocol; this finding was consistent with another study using a known antioxidant such as epigallocatechin gallate [17]. We also demonstrated that NAC induced a decrease in PPARγ protein expression on the fourth day of differentiation process [5], similar to other groups, which confirmed that NAC blocks lipid accumulation by reducing cellular PPARγ protein expression during adipocyte differentiation [18][19][20]. However, the effects of NAC related with PPARγ in mature adipocytes have not yet been studied, which it is essential because adipose tissue is mainly composed of mature adipocytes and in a low percentage by differentiating precursor cells.…”

“…Other authors that have used NAC during adipocyte differentiation, reported similar results [18,20,38,39]. Therefore, we could speculate about a possible use of this molecule as a new drug or as an adjuvant to decrease lipid content in human adipose tissue during obesity development.…”

Insights Into Amentoflavone: A Natural Multifunctional Biflavonoid

“…AMF also protects against liver dysfunction through increasing GSH, SOD level and CAT activities, and decreasing NADPH oxidase activities (Qin et al, 2018). In addition, Chen et al (2016) demonstrate that AMF can protect against high fat dietinduced metabolic dysfunction and inhibit 3T3-L1 adipocyte differentiation. Mechanically, AMF not only promotes ROS generation, but also decreased CCAAT/enhancer-binding protein (C/EBP) β expression, and results in the inhibition of mitotic clonal expansion (MCE) (Chen et al, 2016).…”

Anti-adipogenic and anti-obesity activities of purpurin in 3T3-L1 preadipocyte cells and in mice fed a high-fat diet

“…Fasting mice were orally administered 200 μL of glucose at a dose of 1 g/kg body weight. Blood was collected from the tail vein, and the blood glucose level was determined using an AccuChek Active Kit (Roche Diagnostics, Mannheim, Germany) at 0, 15, 30, 60, and 120 min after glucose challenge [33].…”