The intervention mechanism of Tanshinone IIA in alleviating neuronal injury induced by HMGB1 or TNF-α-mediated microglial activation

Tanshinone IIA (Tan IIA), a neuroprotective natural compound extracted from Salvia miltiorrhiza, is used in stroke treatment. However, elucidating Tan IIA's neuroprotective mechanisms remains challenging due to limitations in assessing drug efficacy and biochemical parameters in clinical studies. This study investigated Tan IIA's impact on neuroinflammatory responses and its neuroprotective mechanisms using HMGB1- or TNF-α-stimulated BV2 microglia in a co-culture system with primary neuron cells. The results indicated that Tan IIA significantly reduced microglial activation induced by TNF-α or HMGB1. Concurrently, Tan IIA disrupted the interactions between HMGB1 and toll-like receptor 4 (TLR4), and between TNF-α and TNF receptor 1 (TNFR1), modulating the HMGB1/TLR4/nuclear factor-kappa B (NF-κB) and TNF-α/TNFR1/NF-κB signaling pathways and related protein expressions. Moreover, co-culture experiments showed that neuronal apoptosis induced by microglial activation was reversed by Tan IIA. In conclusion, Tan IIA provides neuroprotection by modulating signaling pathways in microglia, thus preventing neuronal apoptosis. This study offers new insights into therapeutic targets for ischemic stroke.