The ameliorative effects of capsidiol isolated from elicited Capsicum annuum on mouse splenocyte immune responses and neuroinflammation.
Phytother Res. 2020 Oct 30. Epub 2020 Oct 30. PMID: 33124100
Capsidiol, is an anti-fungal phytoalexin produced by plants of Solanaceae. Capsidiol was examined in cultures of primary splenocytes (SPLCs) isolated from healthy C57BL/6 mice and from those with induced experimental autoimmune encephalomyelitis (EAE) as a mouse model for autoimmune neurodegenerative multiple sclerosis (MS). We also examined the impact of capsidiol in IFN-γ-stimulated mouse BV2 microglial cells. Capsidiol resulted in a significant reduction in the anti-CD3/CD28 (αCD3/CD28)-induced IFN-γCD4(Th1) and IFN-γCD8(Tc1) populations as well as in the production of cytokines (IFN-γ, IL-17A, IL-6, IL-2, TNF-α, and IP-10). Specifically, the CD4and CD8populations (T-betIFN-γ, T-betIFN-γ, and T-betIFN-γ) and cytokine production mediated by Th1/Tc1 polarization were diminished by 25 μM capsidiol. MOGrestimulation of SPLCs from EAE mice resulted in an increase in antigen-specific T cells, including Th1, IL-17ACD4(Th17), and IL-17ACD8(Tc17) populations. By contrast, capsidiol resulted in a decrease in the proportions of Th17 and Tc17 cells; MOG-specific cytokine production was also diminished by capsidiol. Capsidiol treatment resulted in diminished levels of IFN-γ-induced nitric oxide and IL-6; expression of iNOS and COX-2 were suppressed by 50 μM capsidiol in IFN-γ-stimulated BV2 cells. This is the first report of capsidiol-mediated immunomodulatory and antineuroinflammatory activities that may serve to prevent neurodegeneration.