**5. Functions of anthocyanins in health care and cosmetology**

## **5.1 Enhancements of anthocyanins in the immune system**

Free radicals attack the immune system or lymphocytes to damage them, which can result in the decline of cell-mediated immunity and humoral immunity. Free radicals also lead to the decline of immune recognition and the emergence of autoimmune diseases. Studies by Gabriela et al. showed that GSPE can improve the immune suppression induced by ultraviolet irradiation in mice, which may be one of the mechanisms by which GSPE inhibits the light of carcinogenesis [50]. By regulating the differentiation of inflammatory T cells, GSPE can reduce the secretion of interleukin IL-17, IL-21, IL-22, IL-26, and other cytokines and reduce the incidence of inflammation and diseases [51]. Studies showed that proanthocyanidins from *Hippophae rhamnoides* L seed could significantly increase the mice immunity, enhance the mice carbon clearance ability, raise the mice T lymphocyte activity, and promote the hemolysin formation [52]. Hao et al. added proanthocyanidins extracted from *Sorghum* to the feed of ablactation piglets. The IgG, IgM, C3, and IL-2 concentrations of piglets serum significantly increased, which was conducive to improving piglets immunity [53]. In addition, The Institute of Shanghai Nonghao Biological Technology, which studied proanthocyanidins from *Pinus tabulaeformis* Caar as a feed additive, found that proanthocyanidins have antigenic properties,

produce specific immune responses, improve the immune function, and reduce the incidence of livestock and poultry [54].
