scholarly journals Can Polyphenols in Eye Drops Be Useful for Trabecular Protection from Oxidative Damage?

2020 ◽  
Vol 9 (11) ◽  
pp. 3584
Author(s):  
Sergio Claudio Saccà ◽  
Alberto Izzotti ◽  
Stefania Vernazza ◽  
Sara Tirendi ◽  
Sonia Scarfì ◽  
...  

Polyphenols, with anti-oxidant properties, counteract oxidative stress effects. Increasing evidence has found oxidative stressto be the main risk factor for trabecular meshwork (TM) damage, leading to high-tension glaucoma. Topical anti-oxidants could represent a new target for glaucoma treatment. Our aim is to investigate the protective mechanisms on a human TM culture of a patented polyphenol and fatty acid (iTRAB®)formulation in response to oxidative stress using an advanced invitromodel consisting of 3D-human TM cells, embedded in a natural hydrogel, and a milli-scaled multi-organ device model for constantdynamic conditions. The 3D-human TM cells(3D-HTMCs) were treated daily with 500 µM H2O2or 500 µM H2O2and 0.15% iTRAB®(m/v) for 72 h, and molecular differences in the intracellular reactive oxygen species (iROS), state of the cells, activation of the apoptosis pathway and NF-kB and the expression ofinflammatory and fibrotic markers wereanalyzed at different time-points.Concomitant exposure significantly reduced iROS and restored TM viability, iTRAB® having a significant inhibitory effect on the apoptotic pathway, activation of NF-κB, induction of pro-inflammatory (IL-1α, IL-1ß and TNFα) and pro-fibrotic (TGFβ) cytokines and the matrix metalloproteinase expressions. It is clear that this specific anti-oxidant provides a valid TM protection, suggesting iTRAB® could be an adjuvant therapy in primary open-angle glaucoma (POAG).

2006 ◽  
Vol 34 (05) ◽  
pp. 911-922 ◽  
Author(s):  
Dan Luo ◽  
Wei Min ◽  
Xiang-Fei Lin ◽  
Di Wu ◽  
Yang Xu ◽  
...  

One type of traditional Chinese medicines, epigallocatechingallate (EGCG) has been commonly used as a clinical and skin health protective ingredient. It has been known to have photo-protective, anti-inflammatory, and anti-oxidant effects. However, little is known about the mechanisms of EGCG on UV-induced photo-aging and photo-carcinogenesis. In the present study, we investigated the photo-protective mechanisms of EGCG on UVB-induced skin damage, including the potency of EGCG to inhibit the UVB-induced cytotoxicity, secretion of cytokine (IL-6 and TNF-α), cellular apoptosis, expression of apoptosis-regulatory genes (p53–p21) and c-fos gene in cultured immortalized human keratinocyte HaCaT cells. EGCG treatment decreased UVB- induced cell cytotoxicity and apoptosis. It also inhibited the mRNA expressions of apoptosis-regulatory gene (p53 and p21) and c-fos gene. These results suggest that EGCG may have an inhibitory effect on UVB-induced photo-damage and apoptosis by blocking the cytokine secretion and the mRNA expressions of p53, p21 and c-fos genes.


Oncogene ◽  
2021 ◽  
Author(s):  
Angela R. Garcia-Rendueles ◽  
Miguel Chenlo ◽  
Fernando Oroz-Gonjar ◽  
Antonia Solomou ◽  
Anisha Mistry ◽  
...  

AbstractIt is unclear how loss-of-function germline mutations in the widely-expressed co-chaperone AIP, result in young-onset growth hormone secreting pituitary tumours. The RET receptor, uniquely co-expressed in somatotrophs with PIT1, induces apoptosis when unliganded, while RET supports cell survival when it is bound to its ligand. We demonstrate that at the plasma membrane, AIP is required to form a complex with monomeric-intracellular-RET, caspase-3 and PKCδ resulting in PIT1/CDKN2A-ARF/p53-apoptosis pathway activation. AIP-deficiency blocks RET/caspase-3/PKCδ activation preventing PIT1 accumulation and apoptosis. The presence or lack of the inhibitory effect on RET-induced apoptosis separated pathogenic AIP variants from non-pathogenic ones. We used virogenomics in neonatal rats to demonstrate the effect of mutant AIP protein on the RET apoptotic pathway in vivo. In adult male rats altered AIP induces elevated IGF-1 and gigantism, with pituitary hyperplasia through blocking the RET-apoptotic pathway. In females, pituitary hyperplasia is induced but IGF-1 rise and gigantism are blunted by puberty. Somatotroph adenomas from pituitary-specific Aip-knockout mice overexpress the RET-ligand GDNF, therefore, upregulating the survival pathway. Somatotroph adenomas from patients with or without AIP mutation abundantly express GDNF, but AIP-mutated tissues have less CDKN2A-ARF expression. Our findings explain the tissue-specific mechanism of AIP-induced somatotrophinomas and provide a previously unknown tumorigenic mechanism, opening treatment avenues for AIP-related tumours.


Nutrients ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1137 ◽  
Author(s):  
Suhn Kim ◽  
Hyeyoung Kim

Oxidative stress is a major contributor to the pathogenesis of various human diseases as well as to the aging process. Mitochondria, as the center of cellular metabolism and major regulators of redox balance, play a critical role in disease development and progression. Mitochondrial dysfunction involving structural and metabolic impairment is prominent in oxidative stress-related diseases. Increased oxidative stress can damage mitochondria, and subsequent mitochondrial dysfunction generates excesses of mitochondrial reactive oxygen species that cause cellular damage. Mitochondrial dysfunction also activates the mitochondrial apoptotic pathway, resulting in cellular death. Astaxanthin, a red-colored xanthophyll carotenoid, exerts an anti-oxidative and anti-inflammatory effect on various cell lines. In this manner astaxanthin maintains mitochondrial integrity under various pathological conditions. In this review, the inhibitory effects of astaxanthin on oxidative stress-induced mitochondrial dysfunction and related disease development are discussed.


Author(s):  
Krishna Reddy BV ◽  
Avinash Kumar Reddy G ◽  
Sujitha V ◽  
Manasa A

DM otherwise diabetes is now a days an epidemic with the percentage of patient population rising to almost 10% of the world population. Out of all the DM complications, cataract leads the way contributing to disabilities to about 60% of diabetic population. But the pathogenesis of DM cataract is still a half-understood area of medicine there by posing a problem in the therapy. The data that we have till now gives us enough evidence to advocate the oxidative stress has a major role for the pathogenesis of DM complications like DMnephropathy, DMneuropathy, and cardiac hypertrophy, which suggests the oxidative stress is a central feature of diabetes. In the current research, the pharmacological evaluation of Fisetin for its DM based anti-cataract property was performed. This research concentrates to estimate the possible involvement of Nrf-2 / heme oxygenase (HO)-pathway in the observed therapeutic effect, if any. The data obtained in this study also indicate that the observed beneficial effects mainly due to activation of Nrf2/HO-1 pathway. These effects probably result in increased tissue anti-oxidant status as well as decreased free radical production, which ultimately responsible for the observed beneficial effects of Fisetin against hyperglycemia-induced cataract.


2021 ◽  
Vol 18 ◽  
Author(s):  
Francine Rubião ◽  
Alan Cezar Faria Araújo ◽  
João Bernardo Sancio ◽  
Bárbara Silva Nogueira ◽  
Juçara Ribeiro Franca ◽  
...  

Background: The most common treatment for primary open-angle glaucoma (POAG) is the daily use of eye drops. Sustained-release drug delivery systems have been developed to improve patient adherence by achieving prolonged therapeutic drug concentrations in ocular target tissues while limiting systemic exposure. The purpose of this study is to compare the efficacy and safety of bimatoprost inserts with bimatoprost eye drops in patients with POAG and ocular hypertension (OH). Methods: We include OH and POAG patients aged between 40 and 75 years-old. Both OH and POAG patients had intraocular pressure (IOP) greater than 21 and ≤30 mmHg at 9:00 am without glaucoma medication and normal biomicroscopy. Five normal patients with IOP≤14 mmHg constitute the control group. A chitosan-based insert of bimatoprost was placed at the upper conjunctival fornix of the right eye. In the left eye, patients used one drop of LumiganTM daily at 10:00 pm. For statistical analysis, we used a two-way analysis of variance (ANOVA), Student t-test, and paired t-test. Results: Sixteen POAG and 13 OH patients with a mean age of 61 years were assessed. In both eyes, IOP reduction was similar during three weeks of follow-up (19.5±2.2 mmHg and 16.9±3.1 mmHg), insert, and eye drop, respectively; P=0.165). The percentage of IOP reduction in the third week was 30% for insert and 35% for eye drops (P=0.165). No intolerance or discomfort with the insert was reported. Among the research participants, 58% preferred the use of the insert while 25% preferred eye drops, and 17% reported no preference. Conclusions: Bimatoprost-loaded inserts showed similar efficacy to daily bimatoprost eye drops during three weeks of follow up, without major side effects. This might suggest a possible change in the daily therapeutic regimen for the treatment of POAG and OH.


2021 ◽  
Vol 16 (1) ◽  
pp. 537-543
Author(s):  
Mei Zhang ◽  
Jing Yuan ◽  
Rong Dong ◽  
Jingjing Da ◽  
Qian Li ◽  
...  

Abstract Background Hyperhomocysteinemia (HHcy) plays an important role in the progression of many kidney diseases; however, the relationship between HHcy and ischemia-reperfusion injury (IRI)-induced acute kidney injury (IRI-induced AKI) is far from clear. In this study, we try to investigate the effect and possible mechanisms of HHcy on IRI-induced AKI. Methods Twenty C57/BL6 mice were reared with a regular diet or high methionine diet for 2 weeks (to generate HHcy mice); after that, mice were subgrouped to receive sham operation or ischemia-reperfusion surgery. Twenty four hour after reperfusion, serum creatinine, blood urea nitrogen, and Malondialdehyde (MDA) were measured. H&E staining for tubular injury, western blot for γH2AX, JNK, p-JNK, and cleaved caspase 3, and TUNEL assay for tubular cell apoptosis were also performed. Results Our results showed that HHcy did not influence the renal function and histological structure, as well as the levels of MDA, γH2AX, JNK, p-JNK, and tubular cell apoptosis in control mice. However, in IRI-induced AKI mice, HHcy caused severer renal dysfunction and tubular injury, higher levels of oxidative stress, DNA damage, JNK pathway activation, and tubular cell apoptosis. Conclusion Our results demonstrated that HHcy could exacerbate IRI-induced AKI, which may be achieved through promoting oxidative stress, DNA damage, JNK pathway activation, and consequent apoptosis.


2021 ◽  
Vol 10 (5) ◽  
pp. 1148
Author(s):  
Makedonka Atanasovska Velkovska ◽  
Katja Goričar ◽  
Tanja Blagus ◽  
Vita Dolžan ◽  
Barbara Cvenkel

Oxidative stress and neuroinflammation are involved in the pathogenesis and progression of glaucoma. Our aim was to evaluate the impact of selected single-nucleotide polymorphisms in inflammation and oxidative stress genes on the risk of glaucoma, the patients’ clinical characteristics and the glaucoma phenotype. In total, 307 patients with primary open-angle glaucoma or ocular hypertension were enrolled. The control group included 339 healthy Slovenian blood donors. DNA was isolated from peripheral blood. Genotyping was performed for SOD2 rs4880, CAT rs1001179, GPX1 rs1050450, GSTP1 rs1695, GSTM1 gene deletion, GSTT1 gene deletion, IL1B rs1143623, IL1B rs16944, IL6 rs1800795 and TNF rs1800629. We found a nominally significant association of GSTM1 gene deletion with decreased risk of ocular hypertension and a protective role of IL1B rs16944 and IL6 rs1800629 in the risk of glaucoma. The CT and TT genotypes of GPX1 rs1050450 were significantly associated with advanced disease, lower intraocular pressure and a larger vertical cup–disc ratio. In conclusion, genetic variability in IL1B and IL6 may be associated with glaucoma risk, while GPX and TNF may be associated with the glaucoma phenotype. In the future, improved knowledge of these pathways has the potential for new strategies and personalised treatment of glaucoma.


2021 ◽  
Vol 22 (5) ◽  
pp. 2421
Author(s):  
Saray Tabak ◽  
Sofia Schreiber-Avissar ◽  
Elie Beit-Yannai

Reactive oxygen species (ROS) plays a key role in the pathogenesis of primary open-angle glaucoma (POAG), a chronic neurodegenerative disease that damages the trabecular meshwork (TM) cells, inducing apoptosis of the retinal ganglion cells (RGC), deteriorating the optic nerve head, and leading to blindness. Aqueous humor (AH) outflow resistance and intraocular pressure (IOP) elevation contribute to disease progression. Nevertheless, despite the existence of pharmacological and surgical treatments, there is room for the development of additional treatment approaches. The following review is aimed at investigating the role of different microRNAs (miRNAs) in the expression of genes and proteins involved in the regulation of inflammatory and degenerative processes, focusing on the delicate balance of synthesis and deposition of extracellular matrix (ECM) regulated by chronic oxidative stress in POAG related tissues. The neutralizing activity of a couple of miRNAs was described, suggesting effective downregulation of pro-inflammatory and pro-fibrotic signaling pathways, including nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), transforming growth factor-beta 2 (TGF-β2), Wnt/β-Catenin, and PI3K/AKT. In addition, with regards to the elevated IOP in many POAG patients due to increased outflow resistance, Collagen type I degradation was stimulated by some miRNAs and prevented ECM deposition in TM cells. Mitochondrial dysfunction as a consequence of oxidative stress was suppressed following exposure to different miRNAs. In contrast, increased oxidative damage by inhibiting the mTOR signaling pathway was described as part of the action of selected miRNAs. Summarizing, specific miRNAs may be promising therapeutic targets for lowering or preventing oxidative stress injury in POAG patients.


Sign in / Sign up

Export Citation Format

Share Document