Simultaneous determination and anti-inflammatory effects of four phenolic compounds in Dendrobii Herba

Dendrobii Herba, a traditional Korean medicine, is used for treating atrophic gastritis, diabetes and cardiovascular diseases. Phytochemical studies of Dendrobium species and their compounds have been conducted. However, the pharmaceutical effects of these compounds have not yet been elucidated. We performed quantitative determination of four phenolic compounds, - (1) 4-hydroxybenzoic acid, (2) vanillic acid (3) syringic acid and (4) ferulic acid - in Dendrobii Herba using high-performance liquid chromatography coupled with a photodiode array detector. In addition, we investigated the effects of compounds in LPS-stimulated RAW 264.7 cells by measuring of inflammatory mediators. Among the four compounds, 1-3 had a significant inhibitory effect on TNF-α production. The levels of IL-6 were significantly reduced by treatment with compounds 13 and 4 compared with LPS treated cell. All compounds significantly reduced LPS-stimulated PGE₂ production. Thus, these four marker compounds from Dendrobii Herba exhibit anti-inflammatory activity by targeting different inflammation-related cytokines.