Effects of polyphenols on human Th1 and Th2 cytokine production.

BACKGROUND: Numerous phenolic compounds are consumed in the diet in a range of foods. There are very few studies of the effects of these compounds on the production of lymphocyte-derived cytokines. AIM OF THE STUDY: To investigate the effects of five phenolic compounds on cytokine production by cultured human lymphocytes. METHODS: Human whole blood cultures were stimulated with the T cell stimulant concanavalin A for 48 h in the presence of phenolic compounds (vanillic acid, syringic acid, kaempferol, oleuropein and tyrosol) at concentrations up to 10(-4) M. Interleukin (IL)-2, IL-4 and interferon-gamma (IFN-gamma) concentrations were measured in the culture supernatants by ELISA. RESULTS: IFN-gamma concentration was significantly lower in cultures containing 10(-4) M kaempferol than in cultures with kaempferol at 10(-7), 10(-6)and 10(-5) M or without kaempferol. The other phenolic compounds did not affect IFN-gamma concentration and none of the phenolics tested affected IL-2 or IL-4 concentrations. CONCLUSIONS: Some, but not all, phenolic compounds can decrease IFN-gamma production by stimulated human whole blood cultures.

Differential anti-inflammatory effects of phenolic compounds from extra virgin olive oil identified in human whole blood cultures.

OBJECTIVE: The olive oil-rich Mediterranean diet protects against cardiovascular disease, which involves inflammatory processes. This study investigated the effects of phenolic compounds found in extra virgin olive oil on inflammatory mediator production by human mononuclear cells. METHODS: Diluted human blood cultures were stimulated with lipopolysaccharide in the presence of phenolics (vanillic, p-coumaric, syringic, homovanillic and caffeic acids, kaempferol, oleuropein glycoside, and tyrosol) at concentrations of 10(-7) to 10(-4) M. Concentrations of the inflammatory cytokines tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 and of the inflammatory eicosanoid prostaglandin E2 were measured by enzyme-linked immunosorbent assay. RESULTS: Oleuropein glycoside and caffeic acid decreased the concentration of interleukin-1beta. At a concentration of 10(-4) M, oleuropein glycoside inhibited interleukin-1beta production by 80%, whereas caffeic acid inhibited production by 40%. Kaempferol decreased the concentration of prostaglandin E2. At a concentration of 10(-4) M, kaempferol inhibited prostaglandin E2 production by 95%. No effects were seen on concentrations of interleukin-6 or tumor necrosis factor-alpha and there were no effects of the other phenolic compounds. CONCLUSIONS: Some, but not all, phenolic compounds derived from extra virgin olive oil decrease inflammatory mediator production by human whole blood cultures. This may contribute to the antiatherogenic properties ascribed to extra virgin olive oil.