Scope: Most studies on immunomodulatory effects of anthocyanins are concentrated on their anti-inflammatory potential. In vitro studies suggest that anthocyanins possess anti-inflammatory potential, but results from in vivo studies are rare and inconclusive. Sparse information is available about the immune tissues that are affected by anthocyanins. As systemic bioavailability of anthocyanins is rather low, predominantly luminal anthocyanins could influence the gut-associated lymphoid tissue (GALT). Therefore, the present study investigated the immunomodulatory effects of an anthocyanin-rich grape-bilberry juice (ARJ) on the systemic immune system, GALT, and mesenteric adipose tissue (MAT).
Methods and results: Fischer rats (n = 24/group) received ARJ or anthocyanin-depleted grape-bilberry juice (control) for 10 wk. Lymphocytes were isolated from blood, spleen, Peyer's Patches, and mesenteric lymph nodes. Anthocyanin intake was 15 mg/day and concentrations were determined in plasma and intestinal tract. Number of T and natural killer cells, natural killer cell activity, cytokine secretion from lymphocytes (IL-10, IFN-γ, and TNF-α) and MAT (IL-6, IL-10, and MCP-1), inflammation markers in serum (sICAM, IFN-γ, and MCP-1), and activation status of NF-κB were not influenced by ARJ.
Conclusion: This in vivo study suggests that anthocyanins at physiological doses affect neither the systemic immune system, nor GALT, or MAT in healthy, unchallenged rats.
Keywords: Anthocyanins; Gut-associated lymphoid tissue; Immunomodulation; Inflammation; Mesenteric adipose tissue.
© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.