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In inflammation, proinflammatory cytokines induce the formation of large amounts of nitric oxide (NO) by inducible nitric oxide synthase (iNOS), and compounds that inhibit NO production have anti-inflammatory effects. In the present study, we investigated the effects of lansai C and D on NO production in lipopolysaccharide-induced RAW 264.7 cells, and evaluated the mechanisms of action of the compounds. Lansai C and D inhibited iNOS protein and mRNA expression and also NO production in a dose-dependent manner. These compounds inhibited the activation of nuclear factor-kB, which is a significant transcription factor for iNOS and also inhibited the activation of the signal transducer and activator of transcription-1, another important transcription factor for iNOS. The present study characterises the effects and mechanisms of lansais on iNOS expression and NO production in activated macrophages. The results explain the pharmacological efficacy of lansais as anti-inflammatory compounds.

Some endophytic actinomycetes (120) were isolated from the roots of Alpinia galanga. Identification of these endophytes was based on their morphology and amino acid composition of the whole-cell extract. Most isolates were classified as Streptomyces sp.(82), with the remainder belonging to Nocardia sp. (11), Microbispora sp. (3) and Micromonospora sp. (2). Eight isolates were unclassified and 14 were lost during subculture. The strain identified as endophytic Streptomyces sp. Tc022 strongly inhibited Colletotrichum musae and Candida albicans. This endophyte was cultured, the agar was extracted with organic solvent and the extract was purified on a column of silica gel to give a major component, which was identified to be actinomycin D on the basis of spectroscopic data. Actinomycin D showed antifungal activity against Colletotrichum musae and Candida albicans with the MIC of 10 and 20 mg ml -1 , respectively.