Effects of Hypericin on Cultured Primary Normal Human Dermal Fibroblasts Under Increased Oxidative Stress.

INTRODUCTION: Wound healing is a dynamic process that begins with inflammation, proliferation, and cell migration of a variety of fibroblast cells. As a result, identifying possible compounds that may improve fibroblast cell wound healing capacity is crucial. Hypericin is a natural quinine that has been reported to possess a wide range of pharmacological profiles, including antioxidant and anti-inflammatory, activities. Herein we examined for the first time the effect of hypericin on normal human dermal fibroblasts (NHDFs) under oxidative stress. METHODS: NHDF were exposed to different concentrations of hypericin (0-20 µg/mL) for 24 h. For the oxidative stress evaluation, H2O2 was used as a stressor factor. Cell viability and proliferation levels were evaluated. Immunohistochemistry and flow cytometry were performed to assess cell apoptosis levels and with confocal microscopy we identified the mitochondrial superoxide production under oxidative stress and after the treatment with hypericin. Scratch assay was performed under oxidative stress to evaluate the efficacy of hypericin in wound closure. To gain an insight into the molecular mechanisms of hypericin bioactivity, we analyzed the relative expression levels of genes involved in oxidative response and in wound healing process. RESULTS: We found that the exposure of NHDF to hypericin under oxidative stress resulted in an increase in cell viability and ATP levels. We found a decrease in apoptosis and mitochondrial superoxide levels after treatment with hypericin. Moreover, treatment with hypericin reduced wound area and promoted wound closure. The levels of selected genes showed that hypericin upregulated the levels of antioxidants genes. Moreover, treatment with hypericin in wound under oxidative stress downregulated the levels of proinflammatory cytokines, and metalloproteinases; and upregulated transcription factors and extracellular matrix genes. CONCLUSION: These findings indicated that hypericin possesses significant in vitro antioxidant activity on NHDF and provide new insights into its potential beneficial role in the management of diabetic ulcers.

Effects of Advanced Glycation End Products via Oxidative Stress on Beta Cells: Insights from in vitro and in vivo Studies and Update on Emerging Therapies.

BACKGROUND: Protein, lipid, and nucleic acid glycation reactions begin and continue as a result of persistent hyperglycemia in patients with diabetes mellitus. Advanced glycated end products (AGEs) are a complex group of chemical moieties that are formed as a result of the glycation process and play an important role in the pathogenesis of diabetes mellitus. When AGEs interact with their cellular receptor (RAGE), numerous signaling pathways, including nuclear factor kappa-light-chainenhancer of activated B cells (NF-κB), c-Jun N-terminal kinase (JNK), and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), are activated, increasing oxidative stress. OBJECTIVE: The aim of this review was to summarize in vitro and in vivo studies underlining the involvement of AGEs on beta cell dysfunction and death via oxidative stress. METHODS: A literature search of publications published between 1912 and December 2022 was conducted using MEDLINE, EMBASE, and the Cochrane Library, with restrictions on articles written in English. RESULTS: Recent insights have revealed that oxidative stress has a crucial role in the development of beta cell dysfunction and insulin resistance, the major hallmarks of type 2 diabetes mellitus. Studies also revealed that AGEs decrease insulin synthesis and secretion in the pancreatic beta cells and induce cell apoptosis. CONCLUSION: Experimental data have shown that both AGEs and oxidative stress contribute to beta cell dysfunction and development as well as to the progression of diabetic complications. Many anti- AGE therapies are being developed; however, it remains to be seen whether these therapies can help maintain beta cell function and prevent diabetes complications.