Effect of flavonoids from Abelmoschus manihot on proliferation, differentiation of 3T3-L1 preadipocyte and insulin resistance

Abstract

Abelmoschus manihot was rich in flavonoids, which has been reported the activity on protecting angiocarpy and improving renal function. This study aimed to explore the action mechanism of five flavonoids from A. manihot on how to ameliorating insulin resistance through the regulation of the glucose and expression of PPARγ, C/EBPα, SREBP-1, resistin, visfatin, adiponectin in 3T3-L1 adipocytes. After the 3T3-L1 preadipocytes were differentiated into mature adipocytes, insulin resistance model was built. Insulin resistance adipocytes were treated with 5, 100 μmol•L⁻¹ quercetin, isoquercitrin, hyperoside, quercitrin-3'-O-glucoside, gossypetin-8-O-β-glucoside. The glucose was indirectly determined by BCA kit. The mRNA expression levels of PPARγ, C/EBPα, SREBP-1, resistin, visfatin, adiponectin were detected by real-time quantitative PCR. Results showed that five flavonoids at 5 μmol•L⁻¹ could accelerate preadipocytes proliferation and inhibit that at 100 μmol•L⁻¹ Compared with the normal group, glucose uptake reduced significantly in model group (P<0.01). With the treatment of five flavonoids at 100 μmol•L⁻¹, glucose consumption increased significantly (P<0.01). The high expression of PPARγ, C/EBPα, adiponectin expression was significantly increased (P<0.01), and low expression of SREBP-1, resistin, visfatin after respective administration with five flavonoids at 100 μmol•L-1 promoted adipocyte differentiation. This study showed that, HY, JY, QT, QG, GG can control preadipocytes proliferation, promote adipocyte differentiation and regulate the expression of relative factors with lipid metabolism, such as PPARγ, C/EBPα, SREBP-1, adiponectin, resistin, visfatin, increasing glucose utilization and improving insulin resistance in 3T3-L1 adipocyte.