scholarly journals Update on the Effects of Antioxidants on Diabetic Retinopathy: In Vitro Experiments, Animal Studies and Clinical Trials

Antioxidants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 561 ◽  
Author(s):  
Jose Javier Garcia-Medina ◽  
Elena Rubio-Velazquez ◽  
Elisa Foulquie-Moreno ◽  
Ricardo P Casaroli-Marano ◽  
Maria Dolores Pinazo-Duran ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Diabetic Retinopathy ◽  
Animal Studies ◽  
Pressure Control ◽  
Vascular Endothelial Growth Factors ◽  
Vascular Endothelial ◽  
In Vitro Experiments ◽  
Current Therapies ◽  
Endothelial Growth Factors

Current therapies for diabetic retinopathy (DR) incorporate blood glucose and blood pressure control, vitrectomy, photocoagulation, and intravitreal injections of anti-vascular endothelial growth factors or corticosteroids. Nonetheless, these techniques have not been demonstrated to completely stop the evolution of this disorder. The pathophysiology of DR is not fully known, but there is more and more evidence indicating that oxidative stress is an important mechanism in the progression of DR. In this sense, antioxidants have been suggested as a possible therapy to reduce the complications of DR. In this review we aim to assemble updated information in relation to in vitro experiments, animal studies and clinical trials dealing with the effect of the antioxidants on DR.

scholarly journals Neuroprotection as a Therapeutic Target for Diabetic Retinopathy

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
Cristina Hernández ◽  
Massimo Dal Monte ◽  
Rafael Simó ◽  
Giovanni Casini
Keyword(s):  
Clinical Trials ◽  
Diabetic Retinopathy ◽  
Animal Studies ◽  
Vision Loss ◽  
Vascular Lesions ◽  
Vascular Endothelial ◽  
Neuroprotective Strategies ◽  
Current Therapies ◽  
Retinal Neurodegeneration ◽  
Endothelial Growth Factor

Diabetic retinopathy (DR) is a multifactorial progressive disease of the retina and a leading cause of vision loss. DR has long been regarded as a vascular disorder, although neuronal death and visual impairment appear before vascular lesions, suggesting an important role played by neurodegeneration in DR and the appropriateness of neuroprotective strategies. Upregulation of vascular endothelial growth factor (VEGF), the main target of current therapies, is likely to be one of the first responses to retinal hyperglycemic stress and VEGF may represent an important survival factor in early phases of DR. Of central importance for clinical trials is the detection of retinal neurodegeneration in the clinical setting, and spectral domain optical coherence tomography seems the most indicated technique. Many substances have been tested in animal studies for their neuroprotective properties and for possible use in humans. Perhaps, the most intriguing perspective is the use of endogenous neuroprotective substances or nutraceuticals. Together, the data point to the central role of neurodegeneration in the pathogenesis of DR and indicate neuroprotection as an effective strategy for treating this disease. However, clinical trials to determine not only the effectiveness and safety but also the compliance of a noninvasive route of drug administration are needed.

Modulation of Matrix Metalloproteinases by Plant-Derived Products

2020 ◽  
Vol 20 ◽  
Author(s):  
Nur Najmi Mohamad Anuar ◽  
Nurul Iman Natasya Zulkafali ◽  
Azizah Ugusman
Keyword(s):  
Clinical Trials ◽  
Natural Products ◽  
Matrix Metalloproteinases ◽  
Animal Studies ◽  
Current Knowledge ◽  
In Vitro Models ◽  
In Vivo Studies ◽  
Extracellular Matrix Components

: Matrix metalloproteinases (MMPs) are a group of zinc-dependent metallo-endopeptidase that are responsible towards the degradation, repair and remodelling of extracellular matrix components. MMPs play an important role in maintaining a normal physiological function and preventing diseases such as cancer and cardiovascular diseases. Natural products derived from plants have been used as traditional medicine for centuries. Its active compounds, such as catechin, resveratrol and quercetin, are suggested to play an important role as MMPs inhibitors, thereby opening new insights into their applications in many fields, such as pharmaceutical, cosmetic and food industries. This review summarises the current knowledge on plant-derived natural products with MMP-modulating activities. Most of the reviewed plant-derived products exhibit an inhibitory activity on MMPs. Amongst MMPs, MMP-2 and MMP-9 are the most studied. The expression of MMPs is inhibited through respective signalling pathways, such as MAPK, NF-κB and PI3 kinase pathways, which contribute to the reduction in cancer cell behaviours, such as proliferation and migration. Most studies have employed in vitro models, but a limited number of animal studies and clinical trials have been conducted. Even though plant-derived products show promising results in modulating MMPs, more in vivo studies and clinical trials are needed to support their therapeutic applications in the future.

scholarly journals Proteolytic Cleavages in the VEGF Family: Generating Diversity among Angiogenic VEGFs, Essential for the Activation of Lymphangiogenic VEGFs

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 167
Author(s):  
Jaana Künnapuu ◽  
Honey Bokharaie ◽  
Michael Jeltsch
Keyword(s):  
Growth Factors ◽  
Molecular Level ◽  
Specific Antigen ◽  
Receptor Activation ◽  
Vascular Endothelial Growth Factors ◽  
Vascular Endothelial ◽  
Turn On ◽  
C And N ◽  
Proteolytic Cleavages ◽  
Endothelial Growth Factors

Specific proteolytic cleavages turn on, modify, or turn off the activity of vascular endothelial growth factors (VEGFs). Proteolysis is most prominent among the lymph­angiogenic VEGF-C and VEGF-D, which are synthesized as precursors that need to undergo enzymatic removal of their C- and N-terminal propeptides before they can activate their receptors. At least five different proteases mediate the activating cleavage of VEGF-C: plasmin, ADAMTS3, prostate-specific antigen, cathepsin D, and thrombin. All of these proteases except for ADAMTS3 can also activate VEGF-D. Processing by different proteases results in distinct forms of the “mature” growth factors, which differ in affinity and receptor activation potential. The “default” VEGF-C-activating enzyme ADAMTS3 does not activate VEGF-D, and therefore, VEGF-C and VEGF-D do function in different contexts. VEGF-C itself is also regulated in different contexts by distinct proteases. During embryonic development, ADAMTS3 activates VEGF-C. The other activating proteases are likely important for non-developmental lymphangiogenesis during, e.g., tissue regeneration, inflammation, immune response, and pathological tumor-associated lymphangiogenesis. The better we understand these events at the molecular level, the greater our chances of developing successful therapies targeting VEGF-C and VEGF-D for diseases involving the lymphatics such as lymphedema or cancer.

scholarly journals Study of Microvessel Density and the Expression of Vascular Endothelial Growth Factors in Adrenal Gland Pheochromocytomas

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Magdalena Białas ◽  
Grzegorz Dyduch ◽  
Joanna Dudała ◽  
Monika Bereza-Buziak ◽  
Alicja Hubalewska-Dydejczyk ◽  
...  
Keyword(s):  
Growth Factors ◽  
Microvessel Density ◽  
Antiangiogenic Therapy ◽  
Prognostic Significance ◽  
Operation Technique ◽  
Vascular Endothelial Growth Factors ◽  
Vascular Endothelial ◽  
Vascular Architecture ◽  
Laparoscopic Operation ◽  
Endothelial Growth Factors

Angiogenesis (neoangiogenesis), a process of neovascularization, is an essential step for local tumor growth and distant metastasis formation. We have analysed angiogenesis status: vascular architecture, microvessel density, and vascular endothelial growth factors expression in 62 adrenal pheochromocytomas: 57 benign and 5 malignant. Immunohistochemical evaluation revealed that vascular architecture and vessel density are different in the central and subcapsular areas of the tumor. Furthermore, we have observed a strong correlation between number of macrophages and microvessel density in the central and subcapsular areas of the tumor and between the expression of VEGF-A in tumor cells and microvessel density in central and subcapsular areas of the tumor. Secondary changes in these tumors influence the results and both vascular architecture and microvessel density are markedly disturbed by hemorrhagic and cystic changes in pheochromocytomas. These changes are partially caused by laparoscopic operation technique. However, no differences in vascular parameters were found between pheochromocytomas with benign and malignant clinical behavior. Our observation showed that analysis of angiogenesis, as a single feature, does not help in differentiating malignant and benign pheochromocytomas and has no independent prognostic significance. On the other hand, high microvessel density in pheochromocytoma is a promising factor for antiangiogenic therapy in malignant cases.

scholarly journals An observational study of plasma vascular endothelial growth factors (VEGF) A and D expression in non-localized prostate cancer

2012 ◽  
Vol 9 (3) ◽  
pp. 182-189 ◽  
Author(s):  
Brandon P. Verdoorn ◽  
Changyong Feng ◽  
William A. Ricke ◽  
Deepak M. Sahasrabudhe ◽  
Deepak Kilari ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Growth Factors ◽  
Observational Study ◽  
Localized Prostate Cancer ◽  
Vascular Endothelial Growth Factors ◽  
Vascular Endothelial ◽  
Endothelial Growth Factors
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