Screening for bioactive components of Desmodium styracifolium and its mechanisms study based on calcium oxalate monohydrate -induced HK-2 damage model

To screen active components of Desmodium styracifolium in protecting calcium oxalate monohydrate (COM) -induced human proximaltubular epithelial cell (HK-2) damage model, and furtherly explore its mechanism of action, total flavonoids of Desmodium styracifolium (TFDS) and eight flavonoids (schaftoside, isoschaftoside, vicenin-2, isovitexin, isoorientin, apigenin, luteolin and genistein) were tested by COM-induced HK-2 damage model. MTT assay was used to detect the effects of different components on the cell viability of COM-induced HK-2 damage model. The lactate dehydrogenase (LDH) release in the cell supernatant and the activity level of superoxide dismutase (SOD) and reactive oxygen species (ROS) of cell were detected by the kit. Western blot was used to detect the expression levels of NLRP3, caspase-1, HMGB1 in HK-2 of different groups. Compared with the model group, the cell activity was significantly increased after 24 h co-culture with TFDS and four flavonoids (isoorientin, apigenin, genistein and luteolin). These active components can reduce the LDH leakage and ROS in cell supernatant and increase the activity of SOD, with regulating the expression of NLRP3, caspase-1, HMGB1. TFDS, apigenin, isoorientin, luteolin and genistein can protect COM-induced HK-2 cell damage, including enhancing cell viability, protecting cell membrane integrity and enhancing oxidative stress, and regulate the expression of proteins related to NLRP3 inflammasome.