Effects of rooibos tea extract on antigen-specific antibody production and cytokine generation in vitro and in vivo

Authors

Kunishiro K., Tai A., Yamamoto I.

Institution

Department of Immunochemistry, Faculty of Pharmaceutical Sciences, Okayama University, Japan.

Title

Effects of rooibos tea extract on antigen-specific antibody production and cytokine generation in vitro and in vivo.

Source

Bioscience Biotechnology & Biochemistry. 65(10):2137-45, 2001 Oct.

Review

Rooibos tea contains flavonoids which are antioxidants.  This study showed that rooibos tea extract increased antibody production in mice and in the test tube.  The extract increased the amount of interleukin-2 (IL-2) made in the mice.  IL-2 generally improves the function of T-helper cells which are necessary for immune responses.

Abstract

Rooibos tea contains a large amount of flavonoids and acts as a potent antioxidant. In this study, we examined the effects of Rooibos tea extract on antigen-specific antibody production and cytokine generation in vitro and in vivo. The primary in vitro anti-ovalbumin (anti-OVA) or sheep red blood cell (SRBC) antibody production in murine splenocytes was markedly stimulated by the addition of the tea extract at concentrations of 1-100 microg/ml. On the other hand, a nonspecific antibody response elicited with lipopolysaccharide (LPS) in purified splenic B-cells was not modified by the extract. Rooibos tea extract caused an increase in the generation of interleukin 2 (IL-2) both in OVA- and anti-CD3-primed splenocytes at concentrations ranging from 10 microg/ml to 1000 microg/ml. In contrast, this tea extract suppressed the generation of interleukin 4 (IL-4) in OVA-primed splenocytes. Moreover, the reduction of OVA-induced antibody production in serum of the cyclosporin A (CyA) -treated rats can be significantly restored and the IL-2 generation in murine splenocytes was stimulated, following oral administrations of Rooibos tea extract. Thus, our findings suggested that Rooibos tea extract may facilitate the antigen-specific antibody production through selective augmentation of IL-2 generation both in vitro and in vivo. Collectively, Rooibos tea intake may be of value in prophylaxis of the diseases involving a severe defect in Th1 immune response such as cancer, allergy, AIDS, and other infections.

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