Resveratrol delay the cataract formation against naphthalene-induced experimental cataract in the albino rats

Asparagine alleviates naphthalene-induced lens opacity by suppressing ferroptosis

Cataract, with lens opacity as its feature, often cause vision loss. The main clinical treatment is lens replacement surgery, which usually works well for most of the patients, but not for all. And researching drugs to delay or treat cataracts is also very important socially and scientifically. This study explored the effect of asparagine (Asn) on cataracts. In vivo, a naphthalene-induced cataract model in rats was set up, focusing on lens opacity. In vitro, SRA01/04 cells or cultured lenses were treated with the naphthalene metabolite 1,2-dihydroxynaphthalene (1,2-DHN) to study cellular mechanisms. The results showed that Asn effectively reduced lens opacity in rats with naphthalene-induced cataracts. In vitro experiments revealed that the ATF3/GPX4 signaling pathway is involved in the mechanism by which asparagine inhibits ferroptosis in lens epithelial cells induced by 1,2-DHN, playing a crucial role in this process. When given orally, Asn could cut down the accumulation of ferrous ions caused by naphthalene, stop the production of reactive oxygen species (ROS) and malondialdehyde (MDA), and ease the depletion of glutathione (GSH). In short, our findings suggest that Asn can protect against naphthalene-induced cataracts by reducing ferroptosis. This new discovery surely creates new research directions and strategies for future cataract prevention and treatment.

Sagittaria sagittifolia polysaccharide extract regulates Nrf2 to improve endoplasmic reticulum stress-mediated apoptosis in rat cataracts and HLEB3 cells

Age-related cataract (ARC) remains the leading cause of blindness worldwide. Sagittaria sagittifolia polysaccharide (SSP) extract, a key component of Sagittaria sagittifolia L., exhibits anti-oxidant and anti-apoptotic effects with potential applications in ARC. This study aimed to explore the therapeutic potential of SSP in ARC and the underlying mechanisms. In sodium selenite-induced cataracts in rats and hydrogen peroxide (H2O2)-induced human lens epithelial B3 (HLEB3) cells, SSP significantly improved lens opacity and pathological changes and alleviated apoptosis and endoplasmic reticulum stress (ERS)-related injury indicators (by inhibiting the intracellular Ca2+ and protein expression of Bcl-2-associated X, cleaved caspase-3, binding immunoglobulin heavy chain protein, protein kinase RNA-like kinase, inositol-requiring enzyme 1α, activating transcription factor 6, C/EBP homology protein, c-Jun N terminal kinase, caspase-12, and calpain-2). In addition, SSP increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1, sarco/endoplasmic reticulum-type calcium transport ATPase 2, and B-cell lymphoma-2. After applying Nrf2 knockdown technology by transferring short interfering RNA in HLEB3 cells, SSP demonstrated its protective role by activating Nrf2 and inhibiting ERS-mediated apoptosis. These findings indicate that SSP may protect against ARC by regulating Nrf2/ERS-mediated apoptosis, providing potential evidence for its use in preventing or delaying ARC.

Sirtuin 1 Suppresses Hydrogen Peroxide-Induced Senescence and Promotes Viability and Migration in Lens Epithelial Cells by Inhibiting Forkhead Box Protein O1/Toll-Like Receptor 4 Pathway

Age-related cataracts (ARCs) are associated with increased oxidative stress and cellular senescence. Our objective is to investigate the function of Sirtuin 1 (SIRT1) within ARCs. In ARCs tissues and H2O2-treated lens epithelial cells (LECs), the expression levels of SIRT1 were examined. Senescence-associated β-galactosidase (SA-β-gal) staining was employed to evaluate cellular senescence. The Cell Counting Kit-8 assay was employed to measure viability. A wound healing assay was performed to assess migratory capacity in LECs. Oxidative stress-related indicators were determined by enzyme-linked immunosorbent assay kits. Additionally, the Coxpresdb and GeneCards databases were utilized to identify downstream pathways of SIRT1 in ARCs. The expression levels of protein and mRNA were detected using western blot and real-time quantitative polymerase chain reaction, respectively. The expression of SIRT1 was downregulated in ARCs tissues with an increase in reactive oxygen species. In H2O2-induced LECs, SIRT1 was downregulated and its overexpression inhibited oxidative stress and cellular senescence while promoting viability and migration. Furthermore, FoxO1/TLR4 pathway was screened out as the key pathway of SIRT1, which was activated in H2O2-induced LECs senescence. Overexpression of SIRT1 suppressed FoxO1/TLR4 pathway. Further research demonstrated that the activation of FoxO1/TLR4 pathway reversed the inhibitory role of SIRT1 in oxidative stress-induced cellular senescence and the promotion effect of SIRT1 on viability and migration in H2O2-induced LECs. SIRT1 inhibits oxidative stress-induced cellular senescence and promotes the viability and migration in H2O2-induced LECs via suppressing FoxO1/TLR4 pathway.

Oxidative Stress and Cataract Formation: Evaluating the Efficacy of Antioxidant Therapies

This comprehensive review investigates the pivotal role of reactive oxygen species (ROS) in cataract formation and evaluates the potential of antioxidant therapies in mitigating this ocular condition. By elucidating the mechanisms of oxidative stress, the article examines how ROS contribute to the deterioration of lens proteins and lipids, leading to the characteristic aggregation, cross-linking, and light scattering observed in cataracts. The review provides a thorough assessment of various antioxidant strategies aimed at preventing and managing cataracts, such as dietary antioxidants (i.e., vitamins C and E, lutein, and zeaxanthin), as well as pharmacological agents with antioxidative properties. Furthermore, the article explores innovative therapeutic approaches, including gene therapy and nanotechnology-based delivery systems, designed to bolster antioxidant defenses in ocular tissues. Concluding with a critical analysis of current research, the review offers evidence-based recommendations for optimizing antioxidant therapies. The current literature on the use of antioxidant therapies to prevent cataract formation is sparse. There is a lack of evidence-based conclusions; further clinical studies are needed to endorse the use of antioxidant strategies in patients to prevent cataractogenesis. However, personalized treatment plans considering individual patient factors and disease stages can be applied. This article serves as a valuable resource, providing insights into the potential of antioxidants to alleviate the burden of cataracts.

Ultrastructural Changes of Synapses in the Hippocampus of Sprague Dawley Rat Brain following Exposure to Naphthalene Balls

Introduction

The synaptic contacts play an important role in central nervous system (CNS) functioning. Ultrastructural features of synapses in CNS are not studied in naphthalene neurotoxicity model.

Materials and Methodology

In the present work, transmission electron microscopy was used for studying the ultrastructural features of synapses in the hippocampus of Sprague Dawley rat brain, on subsequent exposure to naphthalene balls. The ultrastructural changes were observed for naphthalene low dose (200 mg), high dose (400 mg) after the treatment for 28 days, and post-delayed toxicity phase after 14 days in Sprague Dawley rats.

Results

In comparison with different groups of naphthalene exposure including control and satellite, axon degeneration, axonal demyelination and abnormal synapses was observed in high dose naphthalene administration group. In the post-delayed naphthalene toxicity group, degeneration of synaptic contacts was observed.

Conclusions

This exploration of ultrastructural variations in the synapses of Hippocampus gives information that will be valued in naphthalene neurotoxicological research.

Oxymatrine impedes the progression of endotoxin-induced glaucoma via redox system modulations

This study aimed to provide irrefutable evidence of the preventive effects of oxymatine (OMT) on a model of endotoxin induced glaucoma in Wistar rats which can be attributed to its anti-inflammatory, antioxidant, and TNF-α antagonistic properties. To assess the impact of OMT on uveitic glaucoma, the normal group received 100 μL distilled water topically for 15 days, while the glaucoma control group was induced with uveitic glaucoma by applying 10 μL of 10 μg/mL lipopolysaccharide (LPS) topically for 3 consecutive days. The treatment groups were then given OMT solution at a volume of 50 μL with varying doses of 0.25%, 0.5%, and 1% once a day via topical administration for 15 days. In addition, as a standard, the animals were also given 100 μL of 1% dorzolamide topically for 15 days. All ophthalmic dosing was carried out by pulling the lower eye-lid of the experimental animals and administration of the respective solutions. The study uses cutting-edge real-time imaging of the retinal vasculature in anesthetized animals, postsacrifice lenticular picturization and biochemical evidence to support the changes in the retinal layers. LPS induced animals demonstrated increased IOP, disrupted antioxidant systems, massive lipid damage, enhanced TNF-α activity and changes in intracellular ATPase and ionic activities. The damaged retinal vasculature and lenticular opacification further supported the biochemical evidence. However, using OMT at a 1% dosage effectively enhanced the antioxidant levels, regulated intracellular ion concentration and ATPases, decreased TNF-α activity, and counteracted mechanobiological changes in the visual front and retina. Moreover, OMT can successfully normalize intraocular pressure, making it a highly beneficial treatment option for glaucoma.

Chemical contaminant exposures assessed using silicone wristbands among fuel station attendants, taxi drivers and commercial motorcycle riders in Kampala, Uganda

There are concerns over traffic-related air pollution in Uganda's capital, Kampala. Individuals in the transportation sector are hypothesized to be at greater risk for exposure to volatile organic compounds, given their proximity to vehicle exhaust. Silicone wristbands are a wearable technology that passively sample individuals' chemical exposures. We conducted a pilot cross sectional study to measure personal exposures to volatile organic compounds among 14 transportation workers who wore a wristband for five days. We analyzed for 75 volatile organic compounds; 33 chemicals (35%) were detected and quantified in at least 50% of the samples and 15 (16%) chemicals were detected and quantified across all the samples. Specific chemicals were associated with participants' occupation. The findings can guide future large studies to inform policy and practice to reduce exposure to chemicals in the environment in Kampala.

Inhibition of SIRT1 promotes ultraviolet B induced cataract via downregulation of the KEAP1/NFE2L2 signaling pathway

Due to continuous exposure to ultraviolet B(UVB) radiation, eye lenses are constantly subjected to oxidative stress that induces lens epithelial cell (LEC) apoptosis, which has been associated with the inactivation of Sirtuin1 (SIRT1). It is well-established that NFE2L2 has a major protective effect on UVB-induced oxidative stress and damage. However, whether UVB radiation affects oxidative/antioxidative imbalance and damages LECs by inactivating the protective NFE2L2-mediated antioxidative stress pathway through inhibition of SIRT1 is unknown. In our research, we established in vivo and in vitro UVB exposure models in Sprague Dawley rats and SRA01/04 cells, respectively, to investigate the effect of UVB radiation on the NFE2L2/ KEAP1 pathway and the role of SIRT1 in this process. The in vivo findings revealed that UVB radiation exposure decreased Sirt1 and Nfe2l2 levels, upregulated Keap1 expression, led to an oxidative/antioxidative imbalance and increased LEC apoptosis in the eye lens. Sirt1 downregulated Keap1 expression levels, but activated Nfe2l2 and its downstream target proteins. The in vitro findings showed that UVB inhibited the deacetylation of SIRT1 target proteins and increased the acetylation levels of KEAP1 and NFE2L2. We also found that UVB radiation exposure led to a significant decrease in both co-localization levels and protein interaction between SIRT1 and KEAP1. In addition, the inhibition of SIRT1 increased KEAP1 levels, inhibited the activity of NFE2L2 and decreased co- localization levels and protein interactions between NFE2L2 and KEAP1. These results suggested that UVB radiation decreased SIRT1 levels and inhibited the KEAP1/NFE2L2 pathway, thereby reducing its antioxidant effect, which might be an important mechanism of UVB-induced cataract.

Expression of αA-crystallin (CRYAA) in vivo and in vitro models of age-related cataract and the effect of its silencing on HLEB3 cells

AIM

To investigate the expression of αA-crystallin (CRYAA) in age-related cataract (ARC) models and its role in lens epithelial cells (LECs).

METHODS

We used Flow cytometry to detect the apoptosis and cell cycle in HLEB3 cells and Real-time fluorescence quantitative polymerase chain reaction to detect the expression of CRYAA mRNA in HLEB3 and in rabbit lens. The expression of CRYAA in HLEB3 cells and rabbit lenses as well as the proteins related to apoptosis and autophagy in transfected cells were detected by western blotting. The lens structure in rabbits was investigated using hematoxylin-eosin staining. Protein thermostability assay was performed to detect the thermal stability of rabbit lens proteins. CCK- 8 assay was used to detect the viability of transfected cells, and the transfection was recorded by fluorescence photography.

RESULTS

Hydrogen peroxide can promote apoptosis and arrest the cell cycle in HLEB3 cells, and naphthalene can cause cataract formation and damage the structure of the lens in rabbits. Both ARC models can reduce the expression of CRYAA. The expression of CRYAA silencing increased apoptosis and autophagy in HLEB3 cells.

Antioxidant Nutraceutical Strategies in the Prevention of Oxidative Stress Related Eye Diseases

This review aims to discuss the delicate balance between the physiological production of reactive oxygen species and the role of antioxidant nutraceutical molecules in managing radicals in the complex anatomical structure of the eye. Many molecules and enzymes with reducing and antioxidant potential are present in different parts of the eye. Some of these, such as glutathione, N-acetylcysteine, α-lipoic acid, coenzyme Q10, and enzymatic antioxidants, are endogenously produced by the body. Others, such as plant-derived polyphenols and carotenoids, vitamins B2, C, and E, zinc and selenium, and omega-3 polyunsaturated fatty acids, must be obtained through the diet and are considered essential nutrients. When the equilibrium between the production of reactive oxygen species and their scavenging is disrupted, radical generation overwhelms the endogenous antioxidant arsenal, leading to oxidative stress-related eye disorders and aging. Therefore, the roles of antioxidants contained in dietary supplements in preventing oxidative stress-based ocular dysfunctions are also discussed. However, the results of studies investigating the efficacy of antioxidant supplementation have been mixed or inconclusive, indicating a need for future research to highlight the potential of antioxidant molecules and to develop new preventive nutritional strategies.

Oxidative Stress in the Anterior Ocular Diseases: Diagnostic and Treatment

The eye is a metabolically active structure, constantly exposed to solar radiations making its structure vulnerable to the high burden of reactive oxygen species (ROS), presenting many molecular interactions. The biomolecular cascade modification is caused especially in diseases of the ocular surface, cornea, conjunctiva, uvea, and lens. In fact, the injury in the anterior segment of the eye takes its origin from the perturbation of the pro-oxidant/antioxidant balance and leads to increased oxidative damage, especially when the first line of antioxidant defence weakens with age. Furthermore, oxidative stress is related to mitochondrial dysfunction, DNA damage, lipid peroxidation, protein modification, apoptosis, and inflammation, which are involved in anterior ocular disease progression such as dry eye, keratoconus, uveitis, and cataract. The different pathologies are interconnected through various mechanisms such as inflammation, oxidative stress making the diagnostics more relevant in early stages. The end point of the molecular pathway is the release of different antioxidant biomarkers offering the potential of predictive diagnostics of the pathology. In this review, we have analysed the oxidative stress and inflammatory processes in the front of the eye to provide a better understanding of the pathomechanism, the importance of biomarkers for the diagnosis of eye diseases, and the recent treatment of anterior ocular diseases.

Resveratrol inhibits TGF-β1-induced fibrotic effects in human pterygium fibroblasts

BACKGROUND

Resveratrol is a polyphenolic phytoalexin which has the properties of anti-oxidant, anti-inflammatory and anti-fibrotic effects. The aim of this study was to investigate the anti-fibrotic effects of resveratrol in primary human pterygium fibroblasts (HPFs) and elucidate the underlying mechanisms.

METHOD

Profibrotic activation was induced by transforming growth factor-beta1 (TGF-β1). The expression of profibrotic markers, including type 1 collagen (COL1), α-smooth muscle actin (α-SMA), and fibronectin, were detected by western blot and quantitative real-time-PCR after treatment with various concentrations of resveratrol in HPFs to investigate the anti-fibrotic effects. Relative signaling pathways downstream of TGF-β1 were detected by Western blot to assess the underlying mechanism. Cell viability and apoptosis were assessed using CCK-8 assay and flow cytometry to evaluate proliferation and drug-induced cytotoxicity. Cell migration and contractile phenotype were detected through wound healing assay and collagen gel contraction assay.

RESULTS

The expression of α-SMA, FN and COL1 induced by TGF-β1 were suppressed by treatment with resveratrol in dose-dependent manner. The Smad3, mitogen-activated protein kinase (p38 MAPK) and phosphatidylinositol-3-kinase (PI3K) / protein kinase B (AKT) pathways were activated by TGF-β1, while resveratrol attenuated those pathways. Resveratrol also inhibited cellular proliferation, migration and contractile phenotype, and induced apoptosis in HPFs.

CONCLUSIONS

Resveratrol inhibit TGF-β1-induced myofibroblast activation and extra cellular matrix synthesis in HPFs, at least partly, by regulating the TGF-β/Smad3, p38 MAPK and PI3K/AKT pathways.

Gold Nanoparticles Encapsulated Resveratrol as an Anti-Aging Agent to Delay Cataract Development

Nanoparticle-based drug delivery systems, which can overcome the challenges associated with poor aqueous solubility and other harmful side effects of drugs, display potent applications in cataract treatment. Herein, we designed a nanosystem of gold nanoparticles containing resveratrol (RGNPs) as an anti-aging agent to delay cataracts. The spherical RGNPs had a superior ability to inhibit hydrogen peroxide-mediated oxidative stress damage, including reactive oxygen species (ROS) production, malondialdehyde (MDA) generation, and glutathione (GSH) consumption in the lens epithelial cells. Additionally, the present data showed that RGNPs could delay cellular senescence induced by oxidative stress by decreasing the protein levels of p16 and p21, reducing the ratio of BAX/BCL-2 and the senescence-associated secretory phenotype (SASP) in vitro. Moreover, the RGNPs could also clearly relieve sodium selenite-induced lens opacity in a rat cataract model. Our data indicated that cell senescence was reduced and cataracts were delayed upon treatment with RGNPs through activating the Sirt1/Nrf2 signaling pathway. Our findings suggested that RGNPs could serve as an anti-aging ingredient, highlighting their potential to delay cataract development.

Recent progress and research trend of anti-cataract pharmacology therapy: A bibliometric analysis and literature review

Cataract is the leading cause of blindness worldwide. Cataract phacoemulsification combined with intraocular lens implantation causes great burden to global healthcare, especially for low- and middle-income countries. Such burden would be significantly relieved if cataracts can effectively be treated or delayed by non-surgical means. Excitingly, novel drugs have been developed to treat cataracts in recent decades. For example, oxysterols are found to be able to innovatively reverse lens clouding, novel nanotechnology-loaded drugs improve anti-cataract pharmacological effect, and traditional Chinese medicine demonstrates promising therapeutic effects against cataracts. In the present review, we performed bibliometric analysis to provide an overview perspective regarding the research status, hot topics, and academic trends in the field of anti-cataract pharmacology therapy. We further reviewed the curative effects and molecular mechanisms of anti-cataract drugs such as lanosterol, metformin, resveratrol and curcumin, and prospected the possibility of their clinical application in future.

Resveratrol attenuates behavioural impairment associated with learning and memory in HFD-STZ induced diabetic rats

BACKGROUND AND PURPOSE

Literature have indicated that a high-fat diet (HFD) is a common risk factor for type 2 diabetes mellitus (T2DM) and its associated cognitive-impairments. Mounting evidence supports that, in the diabetic animal model, resveratrol (RSV, SIRT1-modulator) can regulate the fasting glucose and antioxidant levels, as well as the lipid profile, and may alleviate the cognitive-dysfunction associated with diabetes.

EXPERIMENTAL APPROACH

Albino rats were fed 60% HFD-STZ (45mg/kg,i.p, single dose) to induce T2DM so that the experimental T2DM animal model could be used. After 14 weeks of the animals being in a confirmed diabetic condition, they were divided into various groups and treated with metformin(200mg/kg,i.p.) and RSV(50 and 100 mg/kg,i.p.) for four weeks. A multimodal approach involving oxidative-nitroso-stress, SIRT1, TGF-β1 levels, inflammation, cholinergic activity (serum, hippocampus, cerebral cortex), and a battery of behavioural studies associated with learning-memory were performed during and after the experimental-protocol.

KEY RESULTS

The administration of RSV significantly attenuated the increased glucose levels (pre, and post-prandial), impaired glucose tolerance, HbA1c, and decreased the body weights of the T2DM rats. Moreover, RSV ameliorated the impaired learning and memory-associated with increased SIRT1 and the decreased TGF-β1, TNF-α, oxidative-nitroso-stress and cholinergic activities in the serum and the brains of the T2DM-animals.

CONCLUSION AND IMPLICATION

Our investigations demonstrate that SIRT1-modulation can inter-play with TGF-β1 signalling, as well as mitigate hyperglycaemia and subsequent learning-memory impairments, in the T2DM-animals. Moreover, our study showed that novel therapeutic-targets, including TGF-β1, may add to our knowledge of RSV when used in the treatment of impaired memory-associated with diabetes.

Oxymatrine Protects TGFβ1-Induced Retinal Fibrosis in an Animal Model of Glaucoma

Glaucoma has engulfed a huge population of the world into its claws of blindness as it remains asymptomatic until nearly 40% of the neurons are lost and the only option left is for patients to be subjected to symptomatic treatments or surgical methods, neither of which is completely effective in curing the disease as they do not restore the physiological dimensions at the neuronal level. Among the several factors that drive the pathophysiology of glaucoma, one is the involvement of fibrogenic factors, such as transforming growth factor β (TGFβ) which remodels the extracellular matrix (ECM) and, thus, the deposition of fibrotic material in the retina, resulting in the progression of primary open-angle glaucoma (POAG). The primary objectives of this study were to evaluate the protective effects of oxymatrine (OMT) in the steroid-induced glaucoma model in experimental rats and to determine the role of transforming growth factor β1 (TGFβ1) in the pathogenesis of glaucoma and its consequent inhibition due to the antioxidant and the antiinflammatory, and also the TGFβ1 antagonistic, behavior of OMT. To that end, we experimentally elucidated the role of OMT, a TGFβ1 antagonist, that is known to play antiinflammatory and antioxidant roles in the steroid-induced glaucoma model in experimental rats, and using the enzyme-linked immunosorbent assay (ELISA), we observed a direct inhibitory effect of OMT on the pathogenesis of glaucoma. The antioxidant and the antiinflammatory potentials of OMT were determined using several biochemical methods to determine the major antioxidants in the retinal layers, such as superoxide dismutase (SOD), glutathione peroxidase (GP_X), catalase (CAT), and glutathione (GSH), along with the nitrite and the malondialdehyde (MDA) concentration levels. As a result, OMT was found to reduce the total protein content in the retinal layers, a correlation that has not been previously reported. Moreover, the impacts of OMT on the major governing ATPases, namely Na⁺/K⁺ ATPase and Ca²⁺ATPase, along with its impacts on the intracellular ionic concentrations of Na⁺, K⁺, and Ca²⁺, were determined and were found to point toward OMT, restoring homeostasis in glaucomatous animals. A clearer picture of the changes during the treatment was obtained using retinal images of the live animals and of the lenticular changes in the sacrificed animal; these images provided data on the pathological pathways leading to glaucoma inception and its consequent inhibition by OMT. The data reported in this study clearly indicate that OMT has a possible role in inhibiting the pathogenesis of glaucoma, and the data also permit the quantification of several biochemical parameters of concern.

New Highlights of Resveratrol: A Review of Properties against Ocular Diseases

Eye diseases are currently a major public health concern due to the growing number of cases resulting from both an aging of populations and exogenous factors linked to our lifestyles. Thus, many treatments including surgical pharmacological approaches have emerged, and special attention has been paid to prevention, where diet plays a preponderant role. Recently, potential antioxidants such as resveratrol have received much attention as potential tools against various ocular diseases. In this review, we focus on the mechanisms of resveratrol against ocular diseases, in particular age-related macular degeneration, glaucoma, cataract, diabetic retinopathy, and vitreoretinopathy. We analyze, in relation to the different steps of each disease, the resveratrol properties at multiple levels, such as cellular and molecular signaling as well as physiological effects. We show and discuss the relationship to reactive oxygen species, the regulation of inflammatory process, and how resveratrol can prevent ocular diseases through a potential epigenetic action by the activation of sirtuin-1. Lastly, various new forms of resveratrol delivery are emerging at the same time as some clinical trials are raising more questions about the future of resveratrol as a potential tool for prevention or in therapeutic strategies against ocular diseases. More preclinical studies are required to provide further insights into RSV's potential adjuvant activity.

A Ten-Day Grape Seed Procyanidin Treatment Prevents Certain Ageing Processes in Female Rats over the Long Term

Adaptive homeostasis declines with age and this leads to, among other things, the appearance of chronic age-related pathologies such as cancer, neurodegeneration, osteoporosis, sarcopenia, cardiovascular disease and diabetes. Grape seed-derived procyanidins (GSPE) have been shown to be effective against several of these pathologies, mainly in young animal models. Here we test their effectiveness in aged animals: 21-month-old female rats were treated with 500 mg GSPE/kg of body weight for ten days. Afterwards they were kept on a chow diet for eleven weeks. Food intake, body weight, metabolic plasma parameters and tumor incidence were measured. The GSPE administered to aged rats had an effect on food intake during the treatment and after eleven weeks continued to have an effect on visceral adiposity. It prevented pancreas dysfunction induced by ageing and maintained a higher glucagon/insulin ratio together with a lower decrease in ketonemia. It was very effective in preventing age-related tumor development. All in all, this study supports the positive effect of GSPE on preventing some age-related pathologies.

Biochemical Evidence Indicates the Preventive Effect of Resveratrol and Nicotinamide in the Treatment of STZ-induced Diabetic Cataract

PURPOSE

High glucose level is a strong initiator of both oxidative stress and DNA damage to various cellular proteins. This activates the poly ADP-ribose polymerase (PARP) enzyme, which is responsible for disturbing physiological energy metabolic homeostasis. The present study aimed to elucidate the association between stress and the PARP pathway by using resveratrol (RSV) and nicotinamide (NAM, PARP inhibitor) to treat diabetic cataract.

METHOD

Albino rats were used for the experimental study. A single streptozotocin administration (55 mg/kg, i.p.) prompted diabetes in the animals. The experimental groups were the normal group (non-diabetic) and the diabetic groups: the diabetic control animals (group D), the diabetic animals treated with RSV at 40 mg/kg/day, i.p. (D+ RSV group), NAM at 100 and 300 mg/kg/day, i.p. (D+ NAM100, D+ NAM300 groups, respectively), and a combination of RSV and NAM i.p. (D+ RSV+NAM100 = Combi 1 group, D+ RSV+NAM300 = Combi 2 group). Glucose levels and the eyes were examined biweekly; various cataractogenic parameters in the lenses were examined after completion of the eight-week experimental protocol.

RESULTS

Compared to diabetic control, RSV monotherapy significantly decreased hyperglycemia and other lenticular alterations. NAM at the high dose only showed beneficial effects without altering the blood glucose level, lenticular aldose reductase (AR) activity, and sorbitol content, primarily restored the lenticular NAD level and decreased oxidative stress in diabetic rats. These findings regarding NAM treatment indicate that a pathway other than the antioxidant defense system and the polyol pathway, which might be due to PARP inhibition, is involved in diabetic cataracts. Moreover, compared to RSV monotherapy, combination treatments were effective.

CONCLUSION

These results indicate that hyperglycemia and oxidative-osmotic-nitrosative stress play central roles in the pathophysiology of diabetic cataracts. Moreover, our study also revealed that concurrent treatment with the RSV and NAM may prove useful in the pharmacotherapy of diabetes and its secondary complications such as cataract.