Role of Cissus quadrangularis on homeostasis of bone marrow mesenchymal stem cells in diabetic condition

Patients with type 1 diabetes mellitus (DM) are known to have decreased bone density, decreased bone volume, alterations in the bone metabolism, increased fracture rates and delayed fracture healing. DM could have impact on bone through insulinopenia, bone microangiopathy, impaired regulation of mineral metabolism, alterations in local factors that regulate bone remodeling and oxidative stress on osteoblast cells. Studies have shown that, treatment with either insulin or 17-b estradiol (E2) can reverse the altered architecture of the bones in the diabetic rats. Earlier, in our studies we had shown that extract of Cissus quadrangularis (CQ), an Indian herbal medicine mentioned in Ayurveda, acts as an effective osteoprotective medicine in rat models of diabetes induced osteopenia. We had also shown that petroleum ether fraction of CQ (rich in phytoestrogens which may mimic the estrogen) enhances the proliferation and osteoblastogenesis of bone marrow mesenchymal stem cells (BMSCs). The present study is designed to further understand the micromechanism of effect of CQ on BMSCs in hyperglycemic condition. BMSCs were isolated from the healthy Wistar rat and cultured in DMEM and then exposed to normal or osteogenic media with/without hyperglycemic condition. These cells were then treated with reference dose of CQ. At the end of treatment, cell proliferation assay, Alkaline Phosphatase (ALP) staining was done on these cells. Further RNA was isolated to evaluate the pro-osteogenic genes via RT-PCR. Treating the BMSCs grown in hyperglycemic condition with CQ showed increased proliferation rate, enhanced expression of ALP in the cytoplasm and increased expressions of mRNA of Osteocalcin, Bone morphogenetic protein 4 (BMP4) and Osteoprotegerin (OPG). CQ can stimulate the differentiation of BMSCs into osteoblasts in hyperglycemic condition thus help in preventing the osteopenia induced by diabetes. Further, role of phytoestrogens in osteogenic properties of CQ needs to be evaluated.