Effect of cordycepssinensis extract on chronic renal allograft rejection in rats and its action mechanism

Abstract

Objective To investigate the influence of Cordycepssinensis extract on chronic renal allograft rejection in rats and its action mechanism. Methods Brown-Norway rats and Lewis rats were used to establish the kidney transplantation model of chronic rejection. In the allograft control group, saline was given by lavage per day for 8 weeks; In the low dose group, Cordycepssinensis extract was given by lavage at a dosage of 5 mg/kg per day for 8 weeks; In the high dose group, Cordycepssinensis extract was given by lavage at a dosage of 10 mg/kg per day for 8 weeks. In addition, the isograft control group was set up, saline was given by lavage per day for 8 weeks. The kidney was harvested for histology after 8 weeks, and the graft histology was quantified by using the Banff sum score. The distribution of Th17 cells and Treg cells was detected by flow cytometry, and the concentrations of interleukin (IL)-17, IL-23 and IL-2 in the medium were determined at the same time. Results All allografts of each group developed chronic renal allograft rejection 8 weeks after transplantation. The treatment with Cordycepssinensis extract significantly alleviated the chronic renal allograft rejection and the Banff sum score was significantly lower as compared with the allograft control group (P<0.05). As compared with the allograft control group, the ratio of Treg cell in Cordycepssinensis extract treatment groups was remarkably increased (P<0.05), and the ratio of Th17 cells in Cordycepssinensis extract treatment groups was remarkably reduced (P<0.05). Cordycepssinensis extract also remarkably enhanced the production of IL-2 as compared with the allograft control group (P<0.05), while IL-17 and IL-23 levels were significantly lower than those in the allograft control group (P<0.05). Conclusion Cordycepssinensis extract can significantly alleviate the chronic rejection of the renal allograft. Changing the balance of Th17/Treg axis, increasing the anti-inflammatory cytokines and reducing the inflammation cytokines may be involved in the mechanisms. Key words: Cordyceps; Rats; kidney transplantation; Graft rejection; T-Lymphocyte subsets; Cytokines