The Extract of Salvia miltiorrhiza 'Hongdan' Attenuates Inflammation in LPS-Activated BV2 Microglia via ERK1/2, JNK, and p38 MAPK Signaling Inhibition.

Abstract

<p>Background/Objectives: Salvia miltiorrhiza is a medicinal plant rich in phenolic acids and tanshinones, compounds that have been linked to anti-inflammatory and neuroprotective activities. 'Hongdan' is a Korean cultivar characterized by relatively high levels of salvianolic acid B and tanshinone IIA, but its anti-inflammatory activity in microglial cells has not yet been examined. Methods: Nitrite production and the mRNA expression of inflammatory mediators (iNOS and COX-2) and pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) were examined. In addition, activation of MAPK (ERK1/2, JNK, and p38) signaling pathway and expression of the NF-κB regulatory protein IκB-α were analyzed. Results: The Hongdan extract inhibited nitrite production and reduced the expression of iNOS and COX-2 in LPS-stimulated BV2 microglial cells. In addition, the expression of IL-1β and IL-6 was markedly reduced, whereas TNF-α was significantly suppressed only at the highest concentration tested. Furthermore, phosphorylation of ERK1/2, JNK, and p38 was significantly inhibited, while IκB-α degradation was not altered. Conclusions: These findings demonstrate that the Hongdan extract effectively suppresses LPS-induced inflammatory responses through inhibition of MAPK signaling pathways and may serve as a promising natural therapeutic candidate for neuroinflammatory disorders.</p>