The effect of garlic consumption on Th1/Th2 cytokines in phytohemagglutinin (PHA) activated rat spleen lymphocytes.

The balance and regulation of T helper 1 (Th1) and Th2-type cytokines are important in the effective immune response to different diseases. To clarify the effect of garlic (Allium sativum L.) consumption on the Th1/Th2 balance, the secretion of gamma interferon (IFN-gamma) and interleukin-4 (IL-4), as two prototypes of Th1/Th2 cytokines, were compared in serum and supernatant of in vitro phytohemagglutinin activated rat spleen lymphocytes. Thirty male rats were divided equally into two groups. The treatment group received garlic solution in water (600 mg/kg/4 mL) and controls received distilled water by gavage. After 1 month, serum and supernatant of PHA activated spleen lymphocytes were analysed for IFN-gamma and IL-4 by the enzyme-linked immunosorbent assay test and thymus and spleen weights were measured. The garlic treatment group showed significantly decreased production of IFN-gamma from 101.73 +/- 4.62 to 74.64 +/- 4.64 pg/mL and significantly increased IL-4 production from 26.75 +/- 3.35 to 83.92 +/- 6.56 pg/mL (p < 0.001) in the supernatant of PHA induced spleen lymphocytes. The serum level of these cytokines was undetectable. The mean weight of thymuses in the garlic fed animals was significantly reduced from 0.456 +/- 0.016 to 0.368 +/- 0.023 g compared with the control group (p < 0.005). There were no significant differences between the spleen weights in the two groups. In conclusion, oral garlic treatment may favor a Th2 or humoral immune response. (c) 2008 John Wiley & Sons, Ltd.