Antiinflammatory and Analgesic Activities of Ethanol Extract and Isolated Compounds from Millettia pulchra.

The plant Millettia pulchra was commonly used in folk medicine for the management of inflammation. However, there was no scientific rationale for these effects and the mechanism of action remained incompletely understood. The present study was designed to investigate the antiinflammatory and analgesic activities of an ethanol extract of the stem of M. pulchra (EMP) in vivo, and to explore the antiinflammatory activity of compounds isolated from EMP in vitro. We found that EMP reduced xylene-induced ear edema and relieved both acetic acid-induced pain and pain in the hot plate test. Additionally, a significant decrease in nitric oxide (NO) production was observed in cells treated with the isolated compounds. Lanceolatin B, which showed the greatest inhibition of NO synthesis among the compounds tested, also reduced levels of interleukin-1 beta (IL-1β), IL-6, tumor necrosis factor-alpha (TNF-α), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB), and phosphorylation inhibitory kappa B alpha (p-IκBα) in a dose-dependent manner. These findings provide convincing evidence that EMP and the individual isolated compounds possess significant antiinflammatory and analgesic activities.