Background: Currently, diabetes mellitus, specifically, Type 2 diabetes is a multifactorial metabolic disorder that affects more than 348 million people worldwide. It is considered to be one of the main causes of mortality. The pathway of type 2 diabetes is characterized both by insulin resistance in muscle, fat, and liver and a relative failure of the pancreatic β cell. Despite extensive study, yet no unifying hypothesis exists to explain these defects and the proper treatment. The key goal of diabetes treatment is to prevent complications because over time, diabetes can damage the heart, blood vessels, eyes, kidneys, and nerves. Therefore there is a great need to develop new and effective therapies for treating diabetic complications early before it cause irreparable tissue damage. Recently, advances experimental evidence empowers the idea that diabetic patients may greatly benefit from cell-based therapies, which include the use of adult stem and/or progenitor cells in disease therapy.In particular, therapeutic effect of bone marrow stem cell in treating the type 2 diabetic patients.Motivation: Mesenchymal stem cells (MSCs) are adherent and pluripotent and non-hematopoietic progenitor cells. Human bone marrow MSCs have been shown to inhibit antigen-dependent CD4+ and CD8+ T cell proliferation in an allogeneic setting in vitro. They have been found to reside in most organs and tissues investigated to date, including bone marrow, adipose, dermis, muscular tissue, hair follicles, the periodontal ligament and the placenta. In addition, recent studies have shown that adult bone marrow stem cells can differentiate into several types such as blood, liver, lung, skin, muscle, neuron and insulin producing cells. This has motivated us to explore potentials of their therapeutic applications in treating diabetes mellitus or type-2 diabetes. This article proposes a novel mechanism to isolate adult rat bone marrow stem cells and test their ability to treat diabetic rats. The main focus of this research is to investigate the therapeutic effect of mesenchymal stem cells on the diabetic rats. Experimental methods, data and results:The experimental studies were carried out based on twelveweek old healthy Sprague Dawley (S.D) rats and it was used for isolation and transplantation of stem cells. We carried a total number of 40 Sprague Dawley (S.D) male rats; 12-14 weeks old age and weighting 180-250 gm were used in the experimental study. Rats were obtained from Animal House of Nile Center for Experimental Researches, Mansoura, Egypt. Animals were housed in separate metal cages, fresh and clean drinking water was supplied adlibtium through specific nipple. The animals were anesthetized by halothane, and then the skin was sterilized with 70% ethyl alcohol before cutting the skin. The femurs and tibia were carefully dissected from adherent soft tissues. Then they were placed into sterilized beaker containing 70% ethyl alcohol for 1-2 min. The bones were put in Petri dish contain Phosphate buffer saline 1X (PBS) (Hyclone, USA) for w...