TY - JOUR T1 - In Search of New Biological Activities of Isolates from <em>Odontoglossum</em> Harvengtense ‘Tutu’ JF - In Vivo JO - In Vivo SP - 993 LP - 999 VL - 26 IS - 6 AU - RYUICHIRO SUZUKI AU - TOMOHIRO TANAKA AU - MIKI YAMAMOTO AU - HIROSHI SAKAGAMI AU - MINEKO TOMOMURA AU - AKITO TOMOMURA AU - KAZUE SATOH AU - YOSHIAKI SHIRATAKI Y1 - 2012/11/01 UR - http://iv.iiarjournals.org/content/26/6/993.abstract N2 - Background: In the current study, we isolated four known compounds, two phenanthrenes, 2,5-dihydroxy-4,9-dimethoxy phenanthrene [1] and 4-methoxyphenanthrene-2,7-diol (flavanthrinin) [2], one phenanthrenequinone, 5-hydroxy-2,3-dimethoxy-1,4-phenanthrenequinone [3], and one flavone, 3,5,7-trihydroxyflavone (galangin) [4], from the ethyl acetate (EtOAc) extract of Odontoglossum Harvengtense ‘Tutu’ through bioassay-guided fractionation, and investigated their biological activities. Materials and Methods: The isolated compounds were identified with spectroscopic analysis and through comparison to literature values. Cytotoxic activity towards human tumor and normal cells was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Nitric oxide (NO) was determined by the Griess method. Radical scavenging activity was determined by electron spin resonance (ESR) spectroscopy. Osteoclastogenesis was monitored by tartrate-resistant acid phosphatase (TRAP) activity. Results: The compounds had slightly higher cytotoxicity towards human oral squamous cell carcinoma and leukemia cell lines as compared with human normal oral cells, yielding a tumor specificity value of 1.1-2.7. Among these four compounds, 1 most potently inhibited the lipopolysaccharide (LPS)-stimulated NO production and the receptor activator of nuclear factor-κB ligand (RANKL)-stimulated osteoclastogenesis by mouse macrophage-like RAW264.7 cells. Micromolar concentrations of 1 scavenged the NO radical produced from 1-hydroxy-2-oxo-3-(N-3-methyl-3-aminopropyl)-3-methyl-1-triazene. Conclusion: The present study demonstrated, for the first time, that 1 inhibited both macrophage activation and osteoclast differentiation, suggesting its possible anti-inflammatory action. ER -