Whether vitamin A supplementation is effective in T-bet and IFN-ɣ gene expression reduction?

Background: The aim of present study is evaluation of vitamin A supplementation efficacy on IFN-ɣ and T-bet gene expression in atherosclerotic patients.

Methods: Thirty-one patients and 15 healthy controls participated in this study. Healthy control and patients in Vitamin A group received 25 000 IU retinyl palmitate daily for 4 months. Control patients also received 1 pearl of placebo per day up to 4 months. Gene expression levels were assessed by real-time PCR using SYBR green detection method.

Results: IFN-γ gene expression in fresh cells of patients taking vitamin A declined slightly (0.85-fold, p = 0.068), whereas the expression of this gene was increased in patients taking placebo, and in healthy control subjects 1.2-fold (p = 0.267) and 1.7-fold (p = 0.580), respectively. There were no significant difference (p = 0.159) between 3 groups in terms of IFN-γ gene expression in cells stimulated with PHA. In order to determine whether PHA stimulation of PBMCs in vitro had an effect on T-bet expression, we measured the difference between the 3 groups of studied. The results showed significant differences between the groups (p = 0.046). IFN-γ gene expression in cells activated with ox-LDL in healthy control subjects and patients taking vitamin A, was reduced 0.43 (p = 0.0001) and 0.41 (p = 0.001) respectively, but in placebo patients was increased 2.2-fold (p = 0.959).

Conclusion: Considering role of vitamin A on suppression of Th1 cells in atherosclerotic patients, it can be concluded that vitamin A supplementation may be advantageous for these patients.