Sophocarpine attenuates murine lupus nephritis via inhibiting NLRP3 inflammasome and NF-B activation

Inflammation contributes to the pathogenesis of lupus nephritis (LN), which is the most serious complication that increases mortality of systemic lupus erythematosus (SLE). Sophocarpine is a type of quinolizidine alkaloid that possesses anti-inflammatory property. This study investigated the speculation that sophocarpine might play a beneficial effect in LN. Female MRL/lpr mice received sophocarpine treatment for 8weeks. Renal function and histopathology were evaluated. The level of immune complex deposition was measured by immunofluorescent staining, and the levels of proinflammatory cytokines (IL-1, IL-6, and TNF-) and anti-double-stranded DNA (anti-dsDNA) antibodies were measured by ELISA. Western blotting was carried out to evaluate the levels of proteins involved in NLRP3 inflammasome and NF-B pathway. Sophocarpine treatment reduced urine protein excretion, blood urea nitrogen, and attenuated renal tissue damage. The levels of renal immune complex deposition, serum anti-dsDNA, and serum and renal inflammatory cytokines were significantly reduced by sophocarpine. Sophocarpine treatment reduced the levels of proteins that form NLRP3 inflammasome. Activation of NF-B in the kidney was inhibited by sophocarpine. Sophocarpine could ameliorate experimental LN in MRL/lpr. These effects might be through suppressing NLRP3 inflammasome and NF-B pathway.