The etiology, pathogenesis, and pathophysiology of psychiatric disorders are not limited to the brain. Anxiety and depression are normally associated with inflammation reactions and interleukin (IL) related pathways are most evidently involved. Previous animal studies showed that administration of IL-17A induces psoriasis-like inflammation and depression-like behavior, and can be relieved by using IL-17A antibody, while in humans, association studies showed that serum IL-17A and certain downstream ILs are associated with the severity of anxiety. Also, the result of human genetic studies also identified several IL genes associated with anxiety and depression. IL-17A is a sentinel cytokine. On binding with interleukin 17A receptor (IL-17RA) and interleukin 17C receptor (IL-27RC), it induces signaling cascades via nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), P38 mitogen-activated protein kinases (p38MAPK) and CCAAT-enhancer-binding proteins (C/EBPs) knots, and stimulates subsequent cell secretions of cytokines and chemokines. Many studies have demonstrated that consumption of proanthocyanidin-rich or anthocyanin-rich berries, berries juice or other secondary products reduce a variety of inflammation symptoms in humans. However, these berries do not meet a low-cost requirement for general nutritional recommendation and new drug development in Taiwan due to the additional import cost. On the other hand, cyanidin 3-O-glucoside, the main anthocyanin component of local mulberry, competes with IL-17A to bind its receptors and inhibits subsequent downstream cascades. Without interfering the on-going treatment of the patients, this proposal plans to use a single-blinded randomized controlled trial to evaluate the auxiliary effect of mulberry juice in general anxiety disorder, including differences in psychiatric symptoms (anxiety, depression, and functions) and levels of IL-related markers between the experimental and control groups, and contribution of IL-related genes in the auxiliary effect.
