Jolkinolide B Mitigates Cerebral Ischemia-Reperfusion Injury by Promoting Microglial M1/M2 Polarization Through the JAK2/STAT3 Signaling Pathway.

BACKGROUND: Microglia polarization and inflammatory response are closely related to cerebral ischemia-reperfusion injury (CIRI). The diterpenoid compound Jolkinolide B (JB) possesses anti-inflammatory properties, but the effects of JB and the mechanism on CIRI remain unclear. METHODS: An middle cerebral artery occlusion/reperfusion (MCAO/R) rat model and an oxygen-glucose deprivation/reoxygenation (OGD/R)-induced HAPI cell model were used to evaluate the neuroprotective effects and mechanisms of JB. Neurological deficits and histopathological changes were assessed using Longa scoring, corner turn tests, TTC, HE, Nissl, and TUNEL staining. ELISA, flow cytometry, Western blot, and immunofluorescence were employed to analyze pro-inflammatory cytokines, JAK2/STAT3 pathway proteins, and microglial polarization. In vitro, JB's effects on cell viability and apoptosis were evaluated using CCK-8 and LDH release assays. Validation experiments were conducted using the JAK2-specific inhibitor WP1066 and activator Broussonin E. RESULTS: JB exhibited dose-dependent neuroprotective effects in MCAO/R rats, improving neurological function, reducing infarction area, neuronal apoptosis, cerebral edema, and neuroinflammation. JB suppressed JAK2/STAT3 signaling by downregulating p-JAK2, p-STAT3, and M1 markers (iNOS, CD16) while upregulating M2 markers (Arg-1, CD206) and reducing pro-inflammatory cytokines (IL-1β, TNF-α, IFN-γ). Both in vivo and in vitro, JB inhibited the JAK2/STAT3 signaling pathway and promoted microglial polarization from M1 to M2, alleviating CIRI. In vitro, JB enhanced HAPI cell viability, decreased apoptosis, and reduced LDH leakage. CONCLUSION: The ability of JB to modulate microglial polarization through JAK2/STAT3 inhibition presents a promising pharmacological approach for cerebral ischemia-reperfusion injury management in stroke therapy.