Inhibition of nitric oxide production in lipopolysaccharide-activated RAW264.7 macrophages by isolated xanthones from the roots of Cratoxylum formosum ssp. pruniflorum.
The inhibitory activity of extract and compounds isolated from the roots of Cratoxylum formosum ssp. pruniflorum against nitric oxide (NO) was evaluated using RAW264.7 cells. Isolation of the CH2Cl2 extract of C. formosum ssp. pruniflorum roots afforded ten known xanthones including six tri-oxygenated xanthones (1-6) and four tetra-oxygenated xanthones (7-10), respectively. Compound 7 showed the highest inhibitory activity against NO release with an IC50 value of 3.9 μM, followed by compound 8 with an IC50 value of 4.3 μM, respectively. In order to understand the mechanism of this anti-inflammatory activity, the transcriptional level of 7 was found to down regulate mRNA expressions of iNOS and COX-2 in dose-dependent manners, whereas 8 inhibited only iNOS mRNA expression but did not affect on that of COX-2 gene. Xanthones might be the main anti-inflammatory components in C. formosum ssp. pruniflorum.
Faculty of Traditional Thai Medicine, Prince of Songkla University, Hat-Yai, Songkhla, 90112, Thailand, nawong.b@psu.ac.th.
Nawong
N
Boonnak
Suchada
S
Chantrapromma
Supinya
S
Tewtrakul
Teeratad
T
Sudsai
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000302:isolation & purification / Q000494:pharmacology; D002478:Cells, Cultured; D028084:Clusiaceae / Q000737:chemistry*; D051546:Cyclooxygenase 2 / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D015394:Molecular Structure; D009569:Nitric Oxide / Q000096:biosynthesis* / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018517:Plant Roots / Q000737:chemistry*; D044004:Xanthones / Q000302:isolation & purification* / Q000494:pharmacology*
D000893:Anti-Inflammatory Agents; D008070:Lipopolysaccharides; D010936:Plant Extracts; D044004:Xanthones; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C077623:Ptgs2 protein, mouse; D051546:Cyclooxygenase 2