Inhibitory activity against nitric oxide production in macrophage raw 264.7 of proteins from the rhizomes of zingiberaceae plants

Inflammation is one of the most critical factors implicated in carcinogenesis and other degenerative disorders. This study focused on nitric oxide (NO), a molecule that plays a key role in the pathogenesis of inflammation and has been implicated in endotoxin-induced tissue injury. Zingiberaceae is an indigenous plant of tropical region country such as Thailand, which has been traditionally and widely used as an anti-inflammatory agent. In the present study, we investigated the inhibitory activity against nitric oxide production of the crude protein from fifteen of rhizomes of Zingiberaceae plants in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS) and interferon-gramma (IFN-) for induced NO release in cells. The results suggested that the crude protein of Zingiber ottensii Valeton exhibited the highest activity against NO release among fifteen Zingiberaceae plants with an IC50 of 38.6±0.34 µg protein/ml. Moreover, we demonstrated the attenuation in iNOS, IL-6 and TNF-α mRNA expression that was also observed suggesting interference at transcriptional level. The result showed that the crude protein of Z. ottensii decreased cellular iNOS, IL-6 and TNF-α mRNA level. These results suggest that the crude protein possesses a strong anti-inflammatory activity and has a potential to be developed as a therapeutic compound. Furthermore, the analytical SDS-PAGE and mass spectrometry showed a high abundance of protein bands, including lectin, cysteine protease, superoxide dismutase (SOD) that are related with antioxidant activity.