Standardized extract of Centella asiatica ECa 233 inhibits lipopolysaccharide-induced cytokine release in skin keratinocytes by suppressing ERK1/2 pathways

Objective: To evaluate the effect of standardized extract of Centella asiatica ECa 233 on inflammatory mediator production through cyclooxygenase-2 (COX-2), extracellular signal-regulated kinase 1/2 (ERK1/2) and nuclear factor-κB (NF-κB) pathway in keratinocyte HaCaT cells.Methods: HaCaT cells were treated with 0.1, 1, 10 and 100 μg/mL ECa 233 in the presence of lipopolysaccharide (LPS). Proinflammatory cytokines and prostaglandin E2 were assessed with ELISA. Western blotting was used to determine the inhibition of COX-2, ERK1/2 and NF-κB protein expression. Results: ECa 233 suppressed LPS-induced release of interleukin-1β, tumor necrosis factor-α, and prostaglandin E2. ECa 233 also inhibited COX-2, phosphorylation of ERK1/2 and the activation of NF-κB. Moreover, the formation of reactive oxygen species (ROS) was decreased in response to LPS-inflamed keratinocytes. Conclusions: ECa 233 inhibits LPS-stimulated production of inflammatory mediators in keratinocytes via suppressing ERK1/2 and NF-κB pathways. The suppressive effect of ECa 233 may be related to an inhibition of ROS production.

ECa 233 Suppresses LPS-Induced Proinflammatory Responses in Macrophages via Suppressing ERK1/2, p38 MAPK and Akt Pathways.

A current anti-inflammatory agent often targets the prevention of inflammatory disorder development. The standardized Centella asiatica ECa 233 extract has been previously reported for anti-inflammatory effect. This study aimed to investigate its anti-inflammatory effect and mechanisms of ECa 233 in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages, through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, nitric oxide (NO) assay, reactive oxygen species (ROS) production assay, enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. Our results found that ECa 233 significantly inhibited LPS-stimulated pro-inflammatory mediators production including ROS, NO and prostaglandin E2 (PGE2), and pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α and interleukin (IL)-1ß without cytotoxicity. In addition, ECa 233 downregulated not only the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), but also the activation of nuclear factor-kappa B (NF-κB), activated protein kinase B (Akt), extracellular signal-regulated kinase (ERK1/2) and p38 mitogen-activated protein kinases (MAPK) induced by LPS. The inhibition of LPS-induced inflammation due to ECa 233 offered an opportunity as a tentatively potential candidate for the prevention and treatment of inflammatory diseases.