Abstract:
Background Research on the protective effect of glycyrrhizic acid for diabetic nephropathy has achieved great progress. HIF-1α is closely related to the occurrence of diabetic nephropathy, but the mechanism of glycyrrhizic acid and HIF-1α in diabetic nephropathy remains to be explored.
Objective To investigate the effect of glycyrrhizic acid (GA) on inhibiting the inflammatory factors in glomerular mesangial cells SV40 MES13 under high glucose condition by affecting the expression of HIF-1α, so as to provide theoretical reference for the treatment of diabetic nephropathy.
Methods Mouse mesangial cells (SV40 MES13) were cultured and divided into normal group (NG 5.6mmol/L), high glucose group (HG 30mmol/L), and high glucose + glycyrrhizic acid group (HG 30mmol/L + GA 200µmol/L). Western blot was used to detect the expression levels of HIF-1α and VEGF protein factors in cells of different groups, and immunofluorescence was used to detect the expression levels of HIF-1α and VEGF in cells of different groups. The cells were divided into normal group (NG 5.6mmol/L), high glucose group (HG 30mmol/L), high glucose + glycyrrhiza group (HG 30mmol/L + GA 200µmol/L), high glucose + KC7F2 group (HG 30mmol/L + KC7F2 7.5µmol/L), high glucose + glycyrrhizic acid + KC7F2 group (HG 30mmol/L + GA 200µmol/L + KC7F2 7.5µmol/L), high glucose + DMOG group (HG 30mmol/L + DMOG 25µmol/L) and high glucose + glycyrrhizic acid + DMOG group (HG 30mmol/L + GA 200µmol/L + DMOG 25µmol/L) and cultured for 48h. Cell proliferation levels were detected by CCK-8. Western blot and enzyma-linked immunosorbent assay (ELISA) were used to analyze the expression levels of IL-1β, TNF-α, IL-6 and IL-8 in different groups.
Results The results suggested that glycyrrhizic acid could inhibit the expression of HIF-1α and VEGF protein factor in mouse mesangial cells (SV40 MES13) under the condition of high glucose. CCK8 experiment confirmed that HIF-1α up-regulation promoted the proliferation of mouse glomerular cells, glycyrrhizic acid could further inhibit the cell proliferation level induced by the activator DMOG, and could also cooperate with the inhibitor KC7F2 to further inhibit the proliferation level of glomerular mesangial cells. Western blot results showed that glycyrrhizic acid could significantly inhibit the high expression of HIF-1α, VEGF, IL-1β, TNF-α, IL-6, IL-8 protein factor induced by DMOG (P < 0.05), and could also inhibit the protein factor expression HIF-1α, VEGF, IL-1β, TNF-α, IL-6, IL-8 in combination with KC7F2 (P < 0.05). Enzyme-linked immunosorbent assay (ELISA) also showed the same results.
Conclusion GA can inhibit the expression of inflammatory factors in SV40 MES13 cells under high glucose condition by inhibiting expression of HIF-1α.