Effect of Dihuangyinzi-medicated serum on receptor for advanced glycation end product/p38 miotgen-activated protein kinase/nuclear factor-κB pathway in SH-SY5Y cells induced by Aβ1-42

Objective To investigate the effect of Dihuangyinzi (DHYZ)-medicated serum on receptor for advanced glycation end product (RAGE)/p38 miotgen-activated protein kinase (MAPK)/nuclear factor (NF)-κB pathway in SH-SY5Y cells induced by Aβ1-42. Methods Male SD rats were randomly divided into normal control group and experimental group (n=20); natural sera medium and DHYZ sera medium were prepared. (1) SH-SY5Y cells were divided into control group, model group and DHYZ treatment group; natural sera medium, natural sera medium+Aβ1-42 oligomer, and DHYZ sera medium+Aβ1-42 oligomer were given to the cells, respectively. Western blotting was used to detect the protein expressions of NF-κB p65, p38 and phosphorylate (p)-p38. (2) SH-SY5Y cells were given DHYZ sera medium+Aβ1-42 oligomer treatment, and at different time points of Aβ1-42 oligomer treatment (15 min, 30 min, 60 min, 12 h, 24 h, 48 h and 72 h), Western blotting was used to detect the protein expressions of p38 and p-p38. (3) SH-SY5Y cells were divided into 6 groups: mock-transfected RAGE blank group, transfected RAGE blank group, mock-transfected RAGE model group, transfected RAGE model group, mock-transfected RAGE herb group and transfected RAGE herb group; herb groups were given DHYZ-medicated serum; inflammatory factors, interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-a, were measured by ELISA and cytometric bead array. Results (1) As compared with model group, DHYZ treatment group had significantly decreased NF-κB p65 and p-p38/p38 protein expression. (2) The p-p38 protein expression began to increase 30 min after Aβ1-42 treatment, reached to its peak level 24 h after Aβ1-42 treatment, and began to decrease 48 h after Aβ1-42 treatment. (3) The IL-1β, IL-6 and TNF-α levels were increased significantly in the transfected RAGE model group as compared with those in the mock-transfected RAGE model group (P<0.05); the IL-1β, IL-6 and TNF-α levels were increased significantly in the transfected RAGE herb group as compared with those in the mock-transfected RAGE herb group (P<0.05); the IL-1β, IL-6 and TNF-α levels were decreased significantly in the mock-transfected RAGE herb group as compared with those in the mock-transfected RAGE model group (P<0.05); the IL-1β, IL-6 and TNF-α levels were decreased significantly in the transfected RAGE herb group as compared with those in the transfected RAGE model group (P<0.05). Conclusion DHYZ-medicated serum could inhibit the RAGE-p38 pathway and improve the inflammatory reaction in Aβ1-42-induced SH-SY5Y cells transfected with RAGE gene to protect the SH-SY5Y cells. Key words: Alzheimer's disease; Dihuangyinzi; Receptor for advanced glycation end product/p38 miotgen-activated protein kinase/nuclear factor-κB pathway