Ashwagandha root extract exerts anti-inflammatory effects in HaCaT cells by inhibiting the MAPK/NF-[kappa]B pathways and by regulating cytokines

A paste composed of the boiled leaves and roots of the Ashwagandha plant is used to cure ulcer and swelling in Ayurvedic medicine. However, the effects of the hot water extract of Ashwagandha roots (ASH-WEX), which is also used in Ayurveda, on skin have not been fully elucidated. Therefore, the present study investigated the anti-inflammatory activity of ASH-WEX on skin, by using the human keratinocyte cell line HacaT. The results indicated that ASH-WEX significantly inhibited mRNA expression of inflammatory cytokines, including interleukin (IL)-8, IL-6, tumor necrosis factor (TNF-[alpha]), IL-1[beta] and IL-12, and promoted the mRNA expression of the anti-inflammatory cytokine transforming growth factor (TGF)-[beta]1 in HaCaT cells. In addition, ASH-WEX inhibited the lipopolysaccharide-induced phosphorylation of p38 and c-Jun N-terminal kinase, as well as the nuclear translocation of nuclear factor (NF)-[kappa]B p65. Downregulation of TNF-[alpha] mRNA and upregulation of TGF-[beta]1 mRNA were also observed in vivo following ASH-WEX treatment of mouse skin. In conclusion, the present study demonstrated that the anti-inflammatory effect of ASH-WEX may be due to its ability to suppress the NF-[kappa]B and mitogen-activated protein kinase pathways, and to modulate cytokine expression. These results suggest that ASH-WEX can potentially protect against skin inflammation. Key words: Ashwagandha, anti-inflammation, mitogen-activated protein kinase, nuclear factor-[kappa]B, cytokine modulation