(±)-γ-Tocopherol is a form of vitamin E with antioxidant and anti-inflammatory properties. It traps and detoxifies reactive nitrogen oxide species, including nitrogen dioxide, in cell-free assays. It also reduces the synthesis of prostaglandin E2 (PGE2) induced by LPS in RAW 264.7 macrophages and by IL-1β in A549 cells. (±)-γ-Tocopherol inhibits LPS-induced nitrite release and inducible nitric oxide synthase (iNOS) expression in RAW 264.7 cells and reduces COX-2 activity in A549 cells pretreated with IL-1β. Serum levels of (±)-γ-tocopherol are decreased in patients with cardiovascular disease.
γ-CEHC, a metabolite of γ-tocopherol, is predominantly excreted through urine, primarily in its conjugated form as glucuronide [1], rather than through bile.
(±)-5,7-Dimethyltocol is a form of tocopherol. It has similar antioxidant activity to α-tocol, but lower activity than γ-tocol, in antioxidant assays using menhaden oil or squalene as substrates. It also increases microviscosity of rat liver liposomes containing phosphatidylcholine (PC) by 70.6% when used at a molar ratio of 0.2 to PC. (±)-Dimethyltocol has been used as an internal standard for the quantification of 5,7-tocol, α- and γ-tocopherol, and α- and γ-tocopheryl quinone by HPLC.
Jacaric acid is a conjugated polyunsaturated fatty acid first isolated from seeds of Jacaranda plants. Structurally, it is an 18-carbon ω-6 triene isomer of γ-linolenic acid . Jacaric acid induces cell cycle arrest and apoptosis in a variety of cancer cell lines (GI50 = 1-5 μM). It increases the production of reactive oxygen species, and cytotoxicity is abolished by the antioxidant α-tocopherol, suggesting that apoptosis results from oxidative stress. Jacaric acid is metabolized in vivo to conjugated linoleic acid , which is also cytotoxic to cancer cells. Jacaric acid inhibits cyclooxygenase-1 in vitro (Ki = 1.7 μM) and, with long term feeding, decreases stearoyl-CoA desaturase expression and activity in mice.