Effects of Plumbago zeylanica L extract on the secretion of inflammatory factors and extracellular matrix by high glucose-induced glomerular mesangial cells

Objective To investigate the effects of Plumbago zeylanica L extract on the secretion of inflammatory factors and extracellular matrix by high glucose-induced glomerular mesangial cells.Methods Glomerular mesangial mesangial cells from rats were cultured in vitro and randomly divided into control group, model group, low-dose (1 mg/L), medium dose (2 mg/L) and high dose (4 mg/L) Plumbago zeylanica L extract groups, and mannitol (24.5 mmol/L) group. Cells and cell culture media in each group were collected. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and transforming growth factor-β1 (TGF-β1) in cell supernatants were detected by enzyme-linked immunosorbent assay. Superoxide dismutase (SOD) test kit and malondialdehyde (MDA) test kit were used to detect the levels of SOD and MDA in each group. Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the levels of miR-155 and SOCS1 mRNA in the cultured cells in each group. The expressions of fibronectin (FN), human type IV collagen (Col IV) and cytokine signal transduction inhibitor 1 (SOCS1) were detected by western blotting.Results Compared with the control group, the levels of TNF-α, IL-6 and TGF-β1 in the supernatant, MDA, miR-155, FN and Col IV protein in the cells of the model group and mannitol group were significantly increased (P<0.05), and SOD level, SOCS1 mRNA level and protein expression in the cells were significantly decreased (P<0.05). Compared with the model group, the levels of TNF-α, IL-6 and TGF-β1 in the supernatant, MDA, miR-155, FN and Col IV protein in the cells of the low, medium and high dose groups were decreased (P<0.05); SOD level, SOCS1 mRNA level and protein expression in the cells were increased (P<0.05), and all the above changes exhibited dependent on doses of Plumbago zeylanica L extract (P<0.05). Conclusions Plumbago zeylanica L extract can inhibit the secretion of inflammatory factors and extracellular matrix of glomerular mesangial cells induced by high glucose, and down-regulation of the expression of miR-155 and up-regulation of the expression of SOCS1 may be its mechanism.