Inhibitory effect of emodin on raw 264.7 activated with double stranded RNA analogue poly I:C
Background: Emodin (3-methyl-1, 6, 8-trihydroxyanthraquinone) is a compound which can be found in Polygoni Multiflori Radix (PMR). PMR is the root of Polygonum multiflorum. PMR is used to treat dizziness, spermatorrhea, sores, and scrofula as well as chronic malaria traditionally in China and Korea. The anti-tumor property of emodin was already reported. However, anti-viral activity of emodin on macrophages are not fully reported.
Materials and Methods: Effects of emodin on RAW 264.7 mouse macrophages induced by polyinosinic-polycytidylic acid (poly I:C), a synthetic analog of double-stranded RNA, were evaluated.
Results: Emodin restored the cell viability in poly I:C-induced RAW 264.7 at concentrations of up to 50 μM. Emodin significantly inhibited the production of nitric oxide, IL-1α, IL-1β, IL-6, GM-CSF, G-CSF, M-CSF, MCP-1, MIP-1α, MIP-1β, MIP-2, RANTES, and IP-10 as well as calcium release and mRNA expression of signal transducer and activated transcription 1 (STAT1) in poly I:C-induced RAW 264.7 (P < 0.05).
Conclusion: This study shows the inhibitory effect of emodin on poly I:C-induced RAW 264.7 via calcium-STAT pathway.
Keywords: Emodin; dsRNA; Inflammation; Macrophages; Cytokine; Calcium; STAT1