Natural swietenine attenuates diabetic nephropathy by regulating the NF-κB/NLRP3/Caspase-1 signaling pathways: In vivo and in vitro study.

Swietenine (Swi), isolated from Swietenia macrophylla King ameliorates inflammation and oxidative stress, and diabetic nephropathy has a close connection with them. So the effects of Swi on diabetic nephropathy and its mechanism of action was explored. We divided human mesangial cells into five groups and determined the expression of NF-κB and NLRP3 inflammasomes in each group. The levels of inflammatory factors IL-1β and IL-18 were also measured. To explore the relationship between NF-κB and NLRP3, we added PDTC, a specific NF-κB inhibitor, and LPS, and divided the experimental groups into seven groups. We measured the expressions of NF-κB and NLRP3, and then added MCC950, a specific inhibitor of NLRP3 and LPS, the expression of NLRP3, Caspase-1, and IL-1β and IL-18 were measured. Animals divided into four groups and administered over 8 weeks. Protein excretion, creatinine, urea nitrogen, and uric acid were measured. Swi down regulated the expression of NF-κB, NLRP3, and Caspase-1. It reduced the levels of IL-1β and IL-18. PDTC decreased the expression of NF-κB and NLRP3. Compared with the HG + PDTC group, the expression of NF-κB and NLRP3 in the HG + Swi + PDTC group decreased significantly. After adding lipopolysaccharide, the expression of NF-κB and NLRP3 increased, but this situation was reversed after adding Swi. After adding LPS, the expression of NLRP3 and Caspase-1 increased, and the levels of IL-1β and IL-18 also increased, but this situation was reversed after the addition of Swi. Swi significantly improved the renal function of mice with diabetic nephropathy and inhibited the activation of NF-κB and the NLRP3 inflammasome and reduced inflammation by regulating the NF-κB/NLRP3/Caspase-1 signaling pathway, thereby improving diabetic nephropathy.