Current Diabetes Reviews - Volume 14, Issue 1, 2018

Introduction: Beta-cell replacement by human islets or whole pancreas offers a life-saving therapeutic remedy for patients suffering from type 1 diabetes, providing considerable advantages with respect to diminishing total daily insulin dose and lowering frequencies of debilitating hypoglycemic reactions as well as preventing chronic micro- and macrovascular complications. Although remarkable progress has been made in this area, several hurdles remain, hampering its wide-spread applicability. Such hurdles include a limiting supply of islets, the necessity of several donors to achieve enough islet mass for insulin independence, and graft failure because of metabolic pressure, continued autoimmunity, alloimmunity, high concentrations of immunosuppressive drugs as well as oxidative stress caused by hypoxia or inflammation. On the other hand, the islet transplant procedure provides the possibility to undertake multiple practical and beneficial manipulations of the beta cells before engraftment with the intention to reach improved graft survival results. Conclusion: We have focused on the current status of various obstacles in islet transplantation and on the potential of (stem)cell-based treatments able to stimulate islet graft outcome in pre-clinical and clinical transplantation settings in which specific attention is given to the engraftment-enhancing and immunomodulatory potential of various types of stem cells..

Background: More than a decade ago, a new research field named Stem Cell Therapy emerged in Health Science. Initially, it was considered that cells owned a differentiation capability; however, this dogma has changed when new results have been published regarding the ability of the cells to differentiate into different cell tissue mainly due to the novel reprogramming strategies. Accordingly, cells from an adult tissue source may be potentially capable of originating cells of a very different cell type. The possibility of transplanting these cells into damaged organs has triggered many studies to understand the plasticity of stem cells. Today, we have a deeper knowledge about stem cells, however still many questions, especially about the mechanism of action, that needs to be answered. The benefit of stem cells after transplantation has been demonstrated experimentally and also in some cases clinically; however, the extent of stem cell contribution in transplanted tissue has been found to be low and a large number of evidence indicates that a trophic effect should play an important role in such benefit. A better understanding of the paracrine mechanisms involved in this process could be of great relevance in order to focus studies on endogenous cells to direct their function towards the regeneration of damaged tissue. In addition, even more sophisticated methods of reprogramming and cell transplantation have been initiated in combination with bioengineering techniques in order to enhance the potential of these cells. Conclusion: In the present review, we will overview the studies on stem cell and their effects in the treatment of diabetes in order to discuss the questions generated about their origin and the mechanisms that are involved in their reparative properties.

Background: Adult human mesenchymal stem cells retrieved, from the post-partum human umbilical cord Wharton jelly (hUCMS), have recently gained growing interest due to their morphological and functional properties. Objective: The main purpose of our work was to examine morphology and functional properties of hUCMS retrieved from healthy women as compared to those with obesity, or gestational or type 2 diabetes mellitus, under fair metabolic control. Possible differences between groups could shed light into the potential use of these cells for the cell therapy of a variety of diseases, regardless of the obesity/ diabetes status of the donor mothers. Additionally, information on how the maternal disease may affect the cord-derived stem cells, hence possibly newborn children would be important. Methods: We have studied obese/diabetic or normal donor post-partum umbilical cord-derived hUCMS, either in basal or during differentiation protocols into several cell phenotypes and the definitive endoderm. Immunomodulatory properties of these cells, in terms of inhibition of activated lymphocyte proliferation, also was examined. Results: According to our preliminary results, there are functional differences, as assessed by cell and molecular assays, in terms of both, differentiation and immunomodulatory potential, between the cells derived from normal as compared to obese/diabetic mothers. Conclusion: The findings seemingly indicate that the uterine environment of obese/diabetic mothers is quite distant from normal, regardless of metabolic control. Hence hUCMS extracted from obese/diabetic mothers do not appear to be suitable for cell therapy clinical protocols but more studies are required.

Background: Worldwide, Type 2 diabetes has become a growing health problem. While many research articles in the field of ethnopharmacology have focused on the antidiabetic properties of medicinal plant species, insufficient evidence remains regarding their therapeutic use. Studies using both in vitro and in vivo models are necessary to evaluate various medicinal plants species, used in folk medicine, by using scientific criteria. Methods: This review focuses on isolated compounds from medicinal plant species that have reported antidiabetic activity in diabetes models. Searches using MEDLINE/PUBMED and SCOPUS databases were conducted to find articles in English on compounds isolated from plant species that have been tested using in vivo and/or in vitro diabetes models and published between 01/01/2005 and 12/31/2015. Results: The majority of studies involved in vitro assays that used the analysis of enzymes and receptors to investigate the antidiabetic mechanisms of active compounds at the molecular level. Compounds that have been reported to have important anti-diabetic activity with defined mechanisms were identified, including quercetin, oleanolic acid, kaempferol, ursolic acid, rutin, β-sitosterol, and mangiferin. Conclusion: This review contributes to the field of ethnopharmacology and should impact the design of new strategies in the search of novel compounds for the treatment of diabetic conditions.