Resveratrol and curcumin suppress immune response 白藜芦醇与姜黄素的免疫抑制
The role of resveratrol (can be extracted from grape, veratrum album which commonly known as the False Helleborine, also known as White Hellebore, European White Hellebore, White Veratrum) and curcumin (extracted from Turmeric, also known as yellow ginger) is well documented in cancer, inflammation, diabetes and various other diseases. However, their immuinnosuppressive action on T cells, B cells and macrophages is well documented.
In the present study, we have ascertained the effect of resveratrol and curcumin on T and B cells and macrophages. The most striking findings were that both resveratrol and curcumin suppressed the activity of T and B cells and macrophages, as evidenced by significant inhibition in proliferation, antibody production and lymphokine secretion. Interestingly, curcumin imparted immunosuppression by mainly down-regulating the expression of CD28 and CD80 and up-regulating CTLA-4. Resveratrol also functioned by decreasing the expression of CD28 and CD80, as well as by augmenting the production of interleukin (IL)-10.
Finally, we performed further experiments to determine whether other immunoregulatory mechanisms, such as involvement of CD4 + CD25 + regulatory T cells and co-stimulatory molecules CTLA-4, CD28, CD80 and CD40 [1–5], are also responsible for suppressing the immune response mediated by curcumin and resveratrol. Both drugs down-regulated the expression of CD28 on CD4 + T cells and CD80 on macrophages. Further, curcumin also augmented the expression of CTLA-4.None of the molecules showed any influence on CD4 + CD25 + T reg cells, that are known to play a key role in controlling autoimmunity and inflammation [19].
The down-regulation of CD28 attenuates the immune response and renders T cells tolerant. In contrast, up-regulation of CTLA-4 is well documented as suppressing the immune system. Further, it is also a well-established fact that the absence of co-stimulatory molecules such as CD80, CD86 and CD40 can also annul the T cell function [20–23]. Hence, this study reports categorically that curcumin and resveratrol suppress activity of immune cells by affecting the expression of co-stimulatory molecules that are necessary for the activation/inhibition of T cells. Furthermore, they also augment production of IL-10, a suppressor cytokine that plays a regulatory role in controlling the activity of T and B cells [6,7]. Specific immune suppression and induction of anergy are essential processes in the regulation and circumvention of the immune defence. Downregulating the expression of co-stimulatory molecules is a promising therapeutic target to prevent autoimmune diseases, hypersensitivity reactions and allograft rejection. Therefore, the present study suggests the possibility of immunotherapy for immunosuppression, using curcumin and resveratrol by selective regulation of CTLA-4, CD28, CD80 and IL-10.
