Tocotrienols suppress proinflammatory markers and cyclooxygenase-2 expression in RAW264.7 macrophages.
Tocotrienols are powerful chain breaking antioxidant. Moreover, they are now known to exhibit various non-antioxidant properties such as anti-cancer, neuroprotective and hypocholesterolemic functions. This study was undertaken to investigate the anti-inflammatory effects of tocotrienol-rich fraction (TRF) and individual tocotrienol isoforms namely delta-, gamma-, and alpha-tocotrienol on lipopolysaccharide-stimulated RAW264.7 macrophages. The widely studied vitamin E form, alpha-tocopherol, was used as comparison. Stimulation of RAW264.7 with lipopolysaccharide induced the release of various inflammatory markers. 10 mcirog/ml of TRF and all tocotrienol isoforms significantly inhibited the production of interleukin-6 and nitric oxide. However, only alpha-tocotrienol demonstrated a significant effect in lowering tumor necrosis factor-alpha production. Besides, TRF and all tocotrienol isoforms except gamma-tocotrienol reduced prostaglandin E(2) release. It was accompanied by the down-regulation of cyclooxygenase-2 gene expression by all vitamin E forms except alpha-tocopherol. Collectively, the data suggested that tocotrienols are better anti-inflammatory agents than alpha-tocopherol and the most effective form is delta-tocotrienol.
Yam
Mun-Li
ML
Malaysian Palm Oil Board, 6 Persiaran Institusi, Bandar Baru Bangi, 43000, Kajang, Selangor, Malaysia.
Abdul Hafid
Sitti Rahma
SR
Cheng
Hwee-Ming
HM
Nesaretnam
Kalanithi
K
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D051545:Cyclooxygenase 1 / Q000235:genetics / Q000276:immunology; D051546:Cyclooxygenase 2 / Q000235:genetics* / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D015232:Dinoprostone / Q000276:immunology; D005786:Gene Expression Regulation / Q000187:drug effects; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology*; D051379:Mice; D009589:Nitrogen Oxides / Q000276:immunology; D024508:Tocotrienols / Q000737:chemistry / Q000494:pharmacology*; D024502:alpha-Tocopherol / Q000494:pharmacology
D000893:Anti-Inflammatory Agents; D016207:Cytokines; D008070:Lipopolysaccharides; D009589:Nitrogen Oxides; D024508:Tocotrienols; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D024502:alpha-Tocopherol; D015232:Dinoprostone