Vinpocetine Effect on the Juncture of Diabetes and Aging: An in-vitro study.

BACKGROUND: The rapid-growing population of diabetic patients and the elderly are among the direst challenges that the science of medicine is facing today. Targeting these two challenges can shed light on new means to control and ideally reverse this trend. In this experiment, Vinpocetine's effect on aged pancreatic beta-cell functions in correlation with oxidative stress was studied. METHODS: Islet cells were isolated from the pancreas of aged rats and exposed to Vinpocetine, dissolved in acetone and RPMI, for 48 h. Then, senescence-associated molecular parameters, including P16 and P38 gene expressions and ß-galactosidase activity, were investigated along with diabetic and inflammation markers. RESULTS: Experimental results showed that Vinpocetine could significantly increase aged islets insulin secretion and also make a meaningful reduction in oxidative stress markers. This drug can also decrease expression levels of P16 and P38, the primary genes responsible for the aging pathway. TNF-α, IL-6, and NF-κB expressions were also reduced noticeably after treatment with Vinpocetine. CONCLUSION: The current study showed that Vinpocetine, a derivative of the secondary plant metabolite called Vincamine, could break this vicious cycle of oxidative stress and aging by reducing oxidative stress and inflammation, thus inhibiting cellular aging.

Therapeutic Effects of Gallic Acid in Regulating Senescence and Diabetes; an In Vitro Study.

Gallic acid (GA), a plant-derived ubiquitous secondary polyphenol metabolite, can be a useful dietary supplement. This in vitro study's primary purpose was to assess the anti-aging properties of GA using rat embryonic fibroblast (REF) cells, antidiabetic effects via pancreatic islet cells, and finally, elucidating the molecular mechanisms of this natural compound. REF and islet cells were isolated from fetuses and pancreas of rats, respectively. Then, several senescence-associated molecular and biochemical parameters, along with antidiabetic markers, were investigated. GA caused a significant decrease in the ß-galactosidase activity and reduced inflammatory cytokines and oxidative stress markers in REF cells. GA reduced the G0/G1 phase in senescent REF cells that led cells to G2/M. Besides, GA improved the function of the ß cells. Flow cytometry and spectrophotometric analysis showed that it reduces apoptosis via inhibiting caspase-9 activity. Taken together, based on the present findings, this polyphenol metabolite at low doses regulates different pathways of senescence and diabetes through its antioxidative stress potential and modulation of mitochondrial complexes activities.

Cannabinoids as anti-ROS in aged pancreatic islet cells.

AIMS: Cannabinoids are the chemical compounds with a high affinity for cannabinoid receptors affecting the central nervous system through the release of neurotransmitters. However, the current knowledge related to the role of such compounds in the regulation of cellular aging is limited. This study aimed to investigate the effect of cannabidiol and tetrahydrocannabinol on the function of aged pancreatic islets. MAIN METHODS: The expression of p53, p38, p21, p16, and Glut2 genes and ß-galactosidase activity were measured as hallmarks of cell aging applying real-time PCR, ELISA, and immunocytochemistry techniques. Pdx1 protein expression, insulin release, and oxidative stress markers were compared between young and aged rat pancreatic islet cells. KEY FINDINGS: Upon the treatment of aged pancreatic islets cells with cannabidiol and tetrahydrocannabinol, the expression of p53, p38, p21 and the activity of ß-galactosidase were reduced. Cannabidiol and tetrahydrocannabinol increase insulin release, Pdx1, Glut2, and thiol molecules expression, while the oxidative stress parameters were decreased. The enhanced expression of Pdx1 and insulin release in aged pancreatic islet cells reflects the extension of cell healthy aging due to the significant reduction of ROS. SIGNIFICANCE: This study provides evidence for the involvement of cannabidiol and tetrahydrocannabinol in the oxidation process of cellular aging.

Improvement of the functionality of pancreatic Langerhans islets via reduction of bacterial contamination and apoptosis using phenolic compounds.

OBJECTIVES: During type-1 diabetes treating by pancreatic islet transplantation, increasing oxidative stress and microbial contaminations are the main reasons of transplantation failure. In this study, we evaluated anti-apoptotic, antioxidant and antimicrobial potentials of phenolic compounds called ellagic acid (EA) and silybin on rat pancreatic islets. MATERIALS AND METHODS: By doing MTT assay, effective concentrations of EA and silybin were determined as 1500 and 2100 µM, respectively. Then, ELISA methods, flow cytometry and MIC were done to investigate antioxidant, anti-apoptotic and antibacterial effects of those compounds, respectively. RESULTS: Results of FITC Annexin-V and PI staining via flow cytometry, and also caspase-3 and -9 activities performed that EA has anti-apoptotic effects on pancreatic cells. Both compounds significantly diminished reactive oxygen species, and enhanced antioxidant power and insulin secretion. Furthermore, the minimum inhibitory concentration test indicated that these two have antibacterial effects on both Gram-positive and Gram-negative bacteria which usually contaminate the pancreatic islets. CONCLUSION: These findings support that use of EA and silybin can improve the function of islets which are used in transplantation, along with decreasing islets bacterial contamination.

Regulation of aging and oxidative stress pathways in aged pancreatic islets using alpha-lipoic acid.

Oxidative stress has been involved in the aging process and the pathogenesis of type-2 diabetes, which is a serious health problem worldwide. This study investigates the anti-aging, anti-apoptotic, and antioxidant properties of alpha-lipoic acid (ALA), aiming to improve aged rat pancreatic cells. In this regard, half maximal effective concentration (EC50) of ALA based on the survival of aged pancreatic islet cells was determined as 100 µM. Following this, p38 and p53 genes expression as key factors in aging, oxidative stress biomarkers, insulin secretion, and Pdx1 protein expression were evaluated using real-time PCR, ELISA reader, and fluorescence microscope. It was revealed that ALA reduces and controls the effects of aging on beta cells mainly by suppressing p38 and p53 at the gene level (P < 0.001 and P < 0.01), respectively, reducing reactive oxygen species (P < 0.001) and enhancing levels of thiols (P < 0.05) compared with the aged islets. Furthermore, both qualitative and quantitative investigations of insulin secretion have shown that ALA can improve aged cells' function and increase insulin secretion specially in the stimulating concentration of glucose. Also, the expression of Pdx1 was considerably increased by ALA in comparison to the aged pancreatic islets (P < 0.001). As far as the authors of the present study are concerned, this is the first study, which evaluated aging associated with p38 and p53 pathways, oxidative stress parameters, and the expression of insulin in beta cells of an aged rat and reaffirmed the fact that ALA has a significant antioxidant role in reducing the aging process.