Combination therapy with bone marrow-derived mesenchymal stem cell transplantation and propolis improves streptozotocin-induced kidney injury in diabetic rats.

Abstract

Objective: The aim of the current study was to determine the therapeutic effects of combination therapy with propolis extract and rat bone marrow mesenchymal stem cells (MSCs) in streptozotocin (STZ)-induced diabetic rats.

Materials and methods: Firstly, characterization of MSCs was performed and MTT assay was done to determine the optimum concentration of propolis for incubation with MSCs. Rats were divided into 8 groups: Control, diabetic , diabetic+propolis, diabetic+metformin, diabetic+MSCs, diabetic+MSCs+ propolis, diabetic+ MSCs pre-incubated with propolis. MSCs were transplanted via the tail vein on the 7^th and 21^st days of the study. Renal function tests and histopathologic examination were performed for all groups.

Results: Serum glucose concentration in all propolis and MSCs treatment groups was significantly lower than that of the STZ group on the 21^st and 42^nd days of the study. On the 42^nd day, the concentration of serum albumin in the STZ group was significantly lower than the control. Serum albumin concentration in all diabetic groups treated with propolis and MSCs was significantly higher than the diabetic animals. On the 42^nd day, the concentrations of creatinine and urea in the STZ group were significantly higher than all the treatment and control groups. The renal index and histopathological parameters improved in all treatment groups compared with the STZ group.

Conclusion: Our findings demonstrated, MSCs, propolis, and their combination demonstrate positive effects on renal function, kidney index, and histopathology in all treated animals compared with the STZ diabetic rats. These beneficial effects are comparable to those of metformin.