Berberine attenuates the expression of NLRP3 and downstream inflammasome effectors in diabetic retinopathy.

The objective of this study is to investigate the protective effects of berberine (BBR) on diabetic retinopathy (DR) and its regulatory mechanism on NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome pathway. DR rat model was established by Streptozotocin (STZ) injection and treated with BBR. Retinal structure was evaluated by Optical Coherence Tomography (OCT), Hematoxylin and Eosin (HE) staining, and immunofluorescence. NLRP3 pathway proteins were detected by Western blot (WB), and the effects were further studied using RNA interference. BBR significantly improved retinal structure in DR rats and decreased the expression of NLRP3, Cysteine-aspartic acid protease-1(Caspase-1), Gasdermin D (GSDMD), Interleukin-1 beta (IL-1β), and Interleukin-18 (IL-18) (p < 0.05). In an in vitro study using human RPE cells line, BBR administration improved cell viability and reduced RPE pyroptosis, while RNA interference of NLRP3 pathway enhanced BBR's protective effects. BBR ameliorates DR by inhibiting NLRP3 inflammasome-mediated pyroptosis pathway.