Objective To investigate the effects of Shenqitang Shen'an Capsule containing serum on the activity, ultrastructure and NLR family pyrin domain containing 3 (NLRP3) inflammatory vesicles in lipopolysaccharide (LPS)-injured renal tubular epithelial cells.

Methods HK-2 cells were randomly divided into blank group (HK-2+75 μL 7.5% blank serum), LPS group (HK-2+LPS+75 μL 7.5% blank serum), low concentration group (HK-2+LPS+75 μL 2.5% drug-containing serum+75 μL 7.5% blank serum), medium concentration group (HK-2+LPS+75 μL 5% drug-containing serum+75 μL 5% blank serum), and high concentration group (HK-2+LPS+150 μL 10% drug-containing serum). The cell survival rate was detected by CCK-8; the apoptosis rate was detected by flow cytometry; the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA); the ultrastructure of the cells was detected by electron microscopy; the expression of NLRP3 and caspase-1 protein was detected by protein blotting.

Results Compared with the blank group, the cell survival rate was reduced, and apoptosis rate, the level of IL-6, IL-1β, and TNF-α in the cells of the LPS group were significantly decreased (P < 0.05). The cell survival rates in the low concentration group, medium concentration group, and high concentration group were higher than those in the LPS group, while the apoptosis rate and the levels of IL-6, IL-1β, and TNF-α in the cells were lower than those in the LPS group (P < 0.05). Compared with the blank group, LPS group showed obvious programmed necrosis, cell volume increased, cell membrane ruptured and cell necrosis. Compared with LPS group, the cells in the low concentration group, medium concentration group and high concentration group were significantly improved, the number of necrotic cells was reduced, and only a few cell mitochondria were slightly swollen and vacuole-like changes were observed in a dose-dependent manner. Compared with the blank group, the protein expression of NLRP3 and caspase-1 in the cells of the LPS group was significantly increased (P < 0.05). The protein expressions of NLRP3 and caspase-1 in the cells of the low concentration group, medium concentration group, and high concentration group were significantly lower than those in the LPS group (P < 0.05), and the protein expressions of NLRP3 and caspase-1 in the cells of the high concentration group were significantly lower than those in the low concentration group and medium concentration group (P < 0.05).

Conclusion Shenqitang Shen'an Capsule containing serum can inhibit apoptosis of LPS-injured renal tubular epithelial cells, increase cell survival rate, improve ultrastructure, inhibit NLRP3 inflammatory vesicle-mediated inflammatory response, and exert protective effects on AKI.