Osmotic stress induced oxidative damage: possible mechanism of cataract formation in diabetes

A bibliometric and visualized analysis of the pathogenesis of cataracts from 1999 to 2023

Research on the pathogenesis of cataracts is ongoing and the number of publications on this topic is increasing annually. This study offers an overview of the research status, popular topics, and scholarly tendencies in the field of cataract pathogenesis over recent decades，which helps to guide future research directions, and optimize resource allocation. In the present study, we performed a bibliometric analysis of cataract pathogenesis. Publications from January 1, 1999, to December 20, 2023, were collected from the Web of Science Core Collection (WoSCC), and the extracted data were quantified and analyzed. We analyzed and presented the data using Microsoft Excel, VOSviewer, CiteSpace, and Python. In all, 4006 articles were evaluated based on various characteristics, including publication year, authors, countries, institutions, journals, citations, and keywords. This study utilized VOSviewer to conduct visualized analysis, including co-authorship, co-citation, co-occurrence, and network visualization. The CiteSpace software was used to identify keywords with significant bursts of activity. The number of annual global publications climbed from 76 to 277 between 1999 and 2023, a 264.47% rise. Experimental Eye Research published the most manuscripts (178 publications), whereas Investigative Ophthalmology & Visual Science received the most citations (6675 citations). The most influential and productive country, institution, and author were the United States (1244 publications, 54,456 citations), University of California system (136 publications, 5401 citations), and Yao Ke (49 publications, 838 citations), respectively. The top 100 ranked keywords are divided into four clusters through co-occurrence analysis: (1) secondary cataracts, (2) oxidative stress, (3) gene mutations and protein abnormalities, and (4) alteration of biological processes in lens epithelial cells. Further discussions on the four subtopics outline the research topics and trends. In conclusion, the specific mechanism of cataract formation remains a popular topic for future research and should be explored in greater depth.

Mitigation of lens opacification by a functional food in a diabetic rodent model

The current study was designed to test a functional food (FF) mixture containing aldose reductase inhibitors and antiglycation bioactive compounds for suppressing the onset and progression of cataracts in a diabetic rat model. Two-month-old Sprague Dawley rats were grouped as control (C), diabetes untreated (D), and diabetic rats treated with FF at two doses (FF1 = 1.35 g and FF2 = 6.25 g/100g of diet). Diabetes was induced by a single injection of streptozotocin. The FF is a mixture of amla, turmeric, black pepper, cinnamon, ginger, and fenugreek added to the rodent diet. The status of cataracts was monitored weekly by a slit lamp examination for 20 weeks, after which animals were sacrificed to collect eye lenses. Feeding FF1 and FF2 to diabetic rats yielded a significant anti-hyperglycaemic effect and marginally prevented body weight loss. FF delayed cataract progression, and FF2 showed better efficacy than FF1. FF prevented the loss of lens crystallins and their insolubilization in diabetic rats. The antioxidant potential of FF was evident with the lowered protein carbonyls, lipid peroxidation, and prevention of altered antioxidant enzyme activities induced by diabetes. These studies demonstrate the efficacy of plant-derived dietary supplements against the onset and progression of cataracts in a well-established rat model of diabetic eye disease.

Oxidative stress, epigenetic regulation and pathological processes of lens epithelial cells underlying diabetic cataract

Background

Cataract is a blinding disease worldwide. It is an age-related disease that mainly occurs in people over 65 years old. Cataract is also prevalent in patients with diabetes mellites (DM). The pathological mechanisms underlying diabetic cataract (DC) are more complex than that of age-related cataract. Studies have identified that polyol pathway, advanced glycation end products (AGEs) and oxidative stress are the primary pathogenesis of DC. In recent years, molecular-level regulations and pathological processes of lens epithelial cells (LECs) have been confirmed to play roles in the initiation and progression of DC. A comprehensive understanding and elucidation of how chronic hyperglycemia drives molecular-level regulations and cytopathological processes in the lens will shed lights on the prevention, delay and treatment of DC.

Main text

Excessive glucose in the lens enhances polyol pathway and AGEs formation. Polyol pathway causes imbalance in the ratio of NADPH/NADP+ and NADH/NAD+. Decrease in NADPH/NADP+ ratio compromises antioxidant enzymes, while increase in NADH/NAD+ ratio promotes reactive oxygen species (ROS) overproduction in mitochondria, resulting in oxidative stress. Oxidative stress in the lens causes oxidation of DNA, proteins and lipids, leading to abnormalities in their structure and functions. Glycation of proteins by AGEs decreases solubility of proteins. High glucose triggered epigenetic regulations directly or indirectly affect expressions of genes and proteins in LECs. Changes in autophagic activity, increases in fibrosis and apoptosis of LECs destroy the morphological structure and physiological functions of the lens epithelium, disrupting lens homeostasis.

Conclusions

In both diabetic animal models and diabetics, oxidative stress plays crucial roles in the formation of cataract. Epigenetic regulations, include lncRNA, circRNA, microRNA, methylation of RNA and DNA, histone acetylation and pathological processes, include autophagy, fibrosis and apoptosis of LECs also involved in DC.

Effects of Angiotensin Receptor Blockers on Streptozotocin-Induced Diabetic Cataracts

This study aimed to determine the role of oxidative stress produced by the renin-angiotensin system (RAS) in cataract formation in streptozotocin-induced diabetic rats (STZ) using angiotensin II receptor blockers (ARBs). Rats were treated with streptozotocin and orally administered candesartan (2.5 mg/kg/day) or a normal diet for 10 weeks until sacrifice. Cataract progression was assessed through a slit-lamp examination. Animals were euthanized at 18 weeks, and the degree of cataract progression was evaluated. Oxidative stress was also assessed. In STZ-treated rats, lens opacity occurred at 12 weeks. Cataract progression was inhibited in the ARB-treated group compared with the placebo group (p < 0.05). STZ-treated rats exhibited upregulated angiotensin-converting enzyme (ACE) gene expression than control rats. Oxidative stress-related factors were upregulated in the placebo-treated group but suppressed in the ARB-treated group. A correlation coefficient test revealed a positive correlation between ACE gene expression and oxidative stress-related factors and a negative correlation between ACE and superoxide dismutase. Immunostaining revealed oxidative stress-related factors and advanced glycation end products in the lens cortex of the placebo-treated group. The mechanism of diabetic cataracts may be related to RAS, and the increase in focal ACE and angiotensin II in the lens promotes oxidative stress-related factor production.

Insights into the liver-eyes connections, from epidemiological, mechanical studies to clinical translation

Maintenance of internal homeostasis is a sophisticated process, during which almost all organs get involved. Liver plays a central role in metabolism and involves in endocrine, immunity, detoxification and storage, and therefore it communicates with distant organs through such mechanisms to regulate pathophysiological processes. Dysfunctional liver is often accompanied by pathological phenotypes of distant organs, including the eyes. Many reviews have focused on crosstalk between the liver and gut, the liver and brain, the liver and heart, the liver and kidney, but with no attention paid to the liver and eyes. In this review, we summarized intimate connections between the liver and the eyes from three aspects. Epidemiologically, we suggest liver-related, potential, protective and risk factors for typical eye disease as well as eye indicators connected with liver status. For molecular mechanism aspect, we elaborate their inter-organ crosstalk from metabolism (glucose, lipid, proteins, vitamin, and mineral), detoxification (ammonia and bilirubin), and immunity (complement and inflammation regulation) aspect. In clinical application part, we emphasize the latest advances in utilizing the liver-eye axis in disease diagnosis and therapy, involving artificial intelligence-deep learning-based novel diagnostic tools for detecting liver disease and adeno-associated viral vector-based gene therapy method for curing blinding eye disease. We aim to focus on and provide novel insights into liver and eyes communications and help resolve existed clinically significant issues.

In-silico molecular designs to treat neurologic and ophthalmologic diseases caused by sorbitol excess: engineering the Agrobacterium vitis protein

This work presents the design of a new protein based on the adenosine triphosphate-binding cassette (ABC) transporter solute binding protein (SBP) derived from Agrobacterium vitis, a gram-negative plant pathogen. The Protein Data Bank in Europe's dictionary of chemical components was utilized to identify sorbitol and D-allitol. Allitol bound to an ABC transporter SBP was identified in the Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB). Wizard Pair Fitting and Sculpting tools in PyMOL were used to replace bound allitol with sorbitol. PackMover Python code was used to induce mutations in the ABC transporter SBP's binding pocket, and changes in free energy for each protein-sorbitol complex were identified. The results indicate that adding charged side chains forms polar bonds with sorbitol in the binding pocket, thus increasing its stabilization. In theory, the novel protein can be used as a molecular sponge to remove sorbitol from tissue and therefore treat conditions affected by sorbitol dehydrogenase deficiency.

Drug repurposing for reducing the risk of cataract extraction in patients with diabetes mellitus: integration of artificial intelligence-based drug prediction and clinical corroboration

Diabetes mellitus (DM) increases the incidence of age-related cataracts. Currently, no medication is approved or known to delay clinical cataract progression. Using a novel approach based on AI, we searched for drugs with potential cataract surgery-suppressing effects. We developed a drug discovery strategy that combines AI-based potential candidate prediction among 2650 Food and Drug Administration (FDA)-approved drugs with clinical corroboration leveraging multicenter electronic health records (EHRs) of approximately 800,000 cataract patients from the TriNetX platform. Among the top-10 AI-predicted repurposed candidate drugs, we identified three DM diagnostic ICD code groups, such as cataract patients with type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), or hyperglycemia, and conducted retrospective cohort analyses to evaluate the efficacy of these candidate drugs in reducing the risk of cataract extraction. Aspirin, melatonin, and ibuprofen were associated with a reduced 5-, 10-, and 20-year cataract extraction risk in all types of diabetes. Acetylcysteine was associated with a reduced 5-, 10-, and 20-year cataract extraction risk in T2DM and hyperglycemia but not in T1DM patient groups. The suppressive effects of aspirin, acetylcysteine, and ibuprofen waned over time, while those of melatonin became stronger in both genders. Thus, the four repositioned drugs have the potential to delay cataract progression in both genders. All four drugs share the ability to directly or indirectly inhibit cyclooxygenase-2 (COX-2), an enzyme that is increased by multiple cataractogenic stimuli.

Natural Antioxidant Activities of Plants in Preventing Cataractogenesis

A cataract is a condition that causes 17 million people to experience blindness and is the most significant cause of vision loss, around 47.9%. The formation of cataracts is linked to both the production of reactive oxygen species (ROS) and the reduction of endogenous antioxidants. ROS are highly reactive molecules produced by oxygen. Examples of ROS include peroxides, super-oxides, and hydroxyl radicals. ROS are produced in cellular responses to xenobiotics and bacterial invasion and during mitochondrial oxidative metabolism. Excessive ROS can trigger oxidative stress that initiates the progression of eye lens opacities. ROS and other free radicals are highly reactive molecules because their outer orbitals have one or more unpaired electrons and can be neutralized by electron-donating compounds, such as antioxidants. Examples of natural antioxidant compounds are vitamin C, vitamin E, and beta-carotene. Numerous studies have demonstrated that plants contain numerous antioxidant compounds that can be used as cataract preventatives or inhibitors. Natural antioxidant extracts for cataract therapy may be investigated further in light of these findings, which show that consuming a sufficient amount of antioxidant-rich plants is an excellent approach to cataract prevention. Several other natural compounds also prevent cataracts by inhibiting aldose reductase and preventing apoptosis of the eye lens.

The impact of concurrent training and antioxidant supplementation on the factors associated with the ocular lens opacity in diabetic rats

The current study was aimed to investigate the protective effect of vitamins C and E (VCE) supplementation, exercise, and their concurrent application against cataract incidence in the diabetic rats. The obtained results indicated that different supplementation and training treatments were capable to preserve the lens transparency in the diabetic rats. Also, upon applying different supplementation and training treatments, the level of glutathione (GSH) and activity of antioxidant enzymes in the diabetic rats was preserved approximately close to their control levels. In addition, different treatments were capable to maintain the structural integrity of the lens proteins in diabetic rats. Moreover, VCE supplementation, exercise and their simultaneous application prevented lens crystallins of diabetic rats against fibrillation and formation of the increased oligomeric sizes. The results of this study signify the importance of antioxidant supplementation and exercise in reducing the detrimental effects of hyperglycemia on the eye lenses.

Genistein-Opportunities Related to an Interesting Molecule of Natural Origin

Nowadays, increasingly more attention is being paid to a holistic approach to health, in which diet contributes to disease prevention. There is growing interest in functional food that not only provides basic nutrition but has also been demonstrated to be an opportunity for the prevention of disorders. A promising functional food is soybean, which is the richest source of the isoflavone, genistein. Genistein may be useful in the prevention and treatment of such disorders as psoriasis, cataracts, cystic fibrosis, non-alcoholic fatty liver disease and type 2 diabetes. However, achievable concentrations of genistein in humans are low, and the use of soybean as a functional food is not devoid of concerns, which are related to genistein's potential side effects resulting from its estrogenic and goitrogenic effects.

Aldose Reductase: a cause and a potential target for the treatment of diabetic complications

Diabetes mellitus, a disorder of metabolism, results in the elevation of glucose level in the blood. In this hyperglycaemic condition, aldose reductase overexpresses and leads to further complications of diabetes through the polyol pathway. Glucose metabolism-related disorders are the accumulation of sorbitol, overproduction of NADH and fructose, reduction in NAD⁺, and excessive NADPH usage, leading to diabetic pathogenesis and its complications such as retinopathy, neuropathy, and nephropathy. Accumulation of sorbitol results in the alteration of osmotic pressure and leads to osmotic stress. The overproduction of NADH causes an increase in reactive oxygen species production which leads to oxidative stress. The overproduction of fructose causes cell death and non-alcoholic fatty liver disease. Apart from these disorders, many other complications have also been discussed in the literature. Therefore, the article overviews the aldose reductase as the causative agent and a potential target for the treatment of diabetic complications. So, aldose reductase inhibitors have gained much importance worldwide right now. Several inhibitors, like derivatives of carboxylic acid, spirohydantoin, phenolic derivatives, etc. could prevent diabetic complications are discussed in this article.

Oxy-imino saccharidic derivatives as a new structural class of aldose reductase inhibitors endowed with anti-oxidant activity

Aldose reductase is a key enzyme in the development of long term diabetic complications and its inhibition represents a viable therapeutic solution for people affected by these pathologies. Therefore, the search for effective aldose reductase inhibitors is a timely and pressing challenge. Herein we describe the access to a novel class of oxyimino derivatives, obtained by reaction of a 1,5-dicarbonyl substrate with O-(arylmethyl)hydroxylamines. The synthesised compounds proved to be active against the target enzyme. The best performing inhibitor, compound (Z)-8, proved also to reduce both cell death and the apoptotic process when tested in an in vitro model of diabetic retinopathy made of photoreceptor-like 661w cell line exposed to high-glucose medium, counteracting oxidative stress triggered by hyperglycaemic conditions.

Immunoreactivity of ICAM-1, MMP-2, and Nesfatin-1 in lens epithelial cells of patients with diabetes mellitus with or without diabetic retinopathy

PURPOSE

The aim of this study was to evaluate the immunoreactivity of matrix metalloproteinases-2 (MMP-2), intercellular adhesion molecule-1 (ICAM-1), and nesfatin-1 in cataract lens epithelial cells (LECs) of patients with diabetes mellitus (DM) and to investigate the relationship of these markers with DM cataract and diabetic retinopathy (DR).

MATERIALS AND METHODS

Ninety patients were included in the study. The patients were divided into three groups (n = 30): Group 1 (control; patients without DM or DR); Group 2 (patients with DM only), and Group 3 (patients with both DM and DR). Lens capsule samples were collected during intraoperative cataract surgery. Samples were immunohistochemically stained for MMP-2, ICAM-1, and nesfatin-1 and their immunoreactivity was evaluated. The number of immunoreactive cells was determined with a microscope at ×400 magnification.

RESULTS

Increased MMP-2 and ICAM-1 immunoreactivity was detected in the LECs of patients with DM, and especially in patients with DR (p < 0.001, p < 0.001, respectively). Nesfatin-1 immunoreactivity was significantly lower in LECs of diabetic patients (p < 0.001). The mean of MMP-2 immunoreactive cells were 7.47 ± 8.18, 22.80 ± 15.70, and 34.80 ± 20.85 in Groups 1, 2, and 3, respectively. The mean of ICAM-1 immunoreactive cells were 17.10 ± 9.83, 38.50 ± 23.55, and 56.93 ± 20.94 in Groups 1, 2, and 3, respectively.

CONCLUSION

Nesfatin-1, MMP-2, and ICAM-1 and could potentially play important roles in the pathogenesis of cataracts in patients with DM.

Oxidative stress in elderly population: A prevention screening study

Background

Aging is a multifactorial phenomenon, characterized by a progressive decline in the efficiency of biochemical and physiological processes and an increased susceptibility to disease. There is increasing evidence that aging and age‐related disease are correlated with an oxidative stress (OS) condition. The latter is characterized by an imbalance between reactive species (RS), in particular reactive oxygen species (ROS) and antioxidant reserve.

Objectives

The aim of this study is to evaluate the two main markers of oxidative stress, plasmatic peroxide concentration (through d‐ROMs FAST test, derivates‐Reactive Oxygen Metabolites) and plasmatic antioxidant power measured by iron‐reducing power (PAT test, Plasma Antioxidant Test) in 290 apparently healthy volunteers over 60, and their possible correlation with age and gender.

Materials and methods

Human capillary blood samples from healthy volunteers were used in this observational study for the evaluation of the markers of OS.

Results

The data obtained broadly demonstrate that the majority of elderly people display an OS condition characterized by increased levels of peroxides and a slight reduction in antioxidant reserve.

Conclusions

Seniors have a greater propensity to develop a condition of oxidative stress, and therefore it is important to associate the monitoring of oxidative stress markers and, if necessary, antioxidant supplementation, with a healthy lifestyle.

Role of short-wavelength blue light in the formation of cataracts and the expression of caspase-1, caspase-11, Gasdermin D in rat lens epithelial cells: insights into a novel pathogenic mmechanism of cataracts

Background

With the popularity of blue-rich light-emitting diode (LED)-backlit display devices, our eyes are now exposed to more short-wavelength blue light than they were in the past. The goal of this study was to investigate the pathogenesis of cataracts after short-wavelength light exposure.

Methods

Sprague-Dawley (SD) rats were selected and randomly divided into a control group (10 rats each for the 4-, 8-, and 12-week groups) and an experimental group (10 rats each for the 4-, 8-, and 12-week groups). The rats in the experimental group were exposed to a short-wavelength blue LED lamp for 12 h per day. After exposure to the blue LED lamp, the rats were maintained in total darkness for 12 h, after which a 12-h light/dark cycle was resumed. The intensity of the lamp was 3000 lx. At the end of the short-wavelength blue LED lamp exposure (for 4, 8, and 12 weeks), the expression levels of caspase-1, caspase-11 and gasdermin D (GSDMD) were examined in rat lens epithelial cells (LECs) using qRT-PCR and Western blot analyses. An illuminance of 2500 lx was used to study the potential effect of blue LED light on HLE-B3 hLECs in vitro. AC-YVAD-CMK, a caspase-1 inhibitor, was used to confirm the pyroptosis of LECs by flow cytometry.

Results

After 6 weeks, cataracts developed in the experimental rats (4/20 eyes). The clarity of the lens gradually worsened with the duration of exposure. Twelve weeks later, all of the rat eyes had developed cataracts. The expression levels of caspase-1, caspase-11 and GSDMD at 4, 8, and 12 weeks were significantly higher in the samples from rats exposed to a short-wavelength blue LED lamp than in the samples from control rats (p<0.05). The proportions of double-positive hLECs were significantly increased in the 5-h and 10-h short-wavelength blue light exposure subgroups compared with the 5-h and 10-h caspase-1 inhibitor subgroups (p < 0.05).

Conclusion

The data indicate that pyroptosis plays a key role in cataract induction after short-wavelength blue light exposure. This study might provide new insights into a novel pathogenic mechanism of cataracts.

Effect of Berberine on Glycation, Aldose Reductase Activity, and Oxidative Stress in the Lenses of Streptozotocin-Induced Diabetic Rats In Vivo-A Preliminary Study

Diabetes mellitus affects the eye lens, leading to cataract formation by glycation, osmotic stress, and oxidative stress. Berberine, an isoquinoline alkaloid, is a natural compound that has been reported to counteract all these pathological processes in various tissues and organs. The goal of this study was to evaluate whether berberine administered at a dose of 50 mg/kg by oral gavage for 28 days to rats with streptozotocin-induced diabetes reveals such effects on the biochemical parameters in the lenses. For this purpose, the following lenticular parameters were studied: concentrations of soluble protein, non-protein sulfhydryl groups (NPSH), advanced oxidation protein products (AOPP), advanced glycation end-products (AGEs), thiobarbituric acid reactive substances (TBARS), and activities of aldose reductase (AR), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Diabetes induced unfavorable changes in the majority of the examined parameters. The administration of berberine resulted in an increased soluble protein level, decreased activity of AR, and lowered AOPP and AGEs levels. The results suggest that berberine administered orally positively affects the lenses of diabetic rats, and should be further examined with regard to its anticataract potential.

Therapeutic effect of hydrogen peroxide via altered expression of glutathione S-transferase and peroxiredoxin-2 in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) has a high incidence and mortality that epitomizes one of the prominent causes of cancer-related death globally. Novel therapeutic approaches are therefore required. Reactive oxygen species (ROS) are necessary for maintaining cell cycle. Although ROS is involved in HCC progression, hydrogen peroxide (H₂O₂) has anti-proliferative effect on HCC.

METHOD

HCC Huh-7 cells were cultured and incubated with various concentrations of H₂O₂. Paraoxonase activity, levels of malondialdehyde, glutathione and protein oxidation were measured in treated and untreated Huh-7 cells. Furthermore, untreated and treated Huh-7 cells were subjected to two dimensional gel electrophoresis and identified protein spots which were differentially expressed by LC-MS/MS analysis. qRT-PCR was performed to validate the identified proteins.

RESULTS

H₂O₂ depleted glutathione (GSH) with the concomitant up-regulation of GSTP1 and Prx2. H₂O₂ also increased malondialdehyde and protein oxidation, decreased the activity of paraoxonase in Huh-7 cells.

CONCLUSION

H₂O₂ could be used as a novel therapeutic agent that might be beneficial in inducing cell cytotoxicity and hence suppress HCC proliferation.

Risk factors for endothelial cell damage in diabetics after phacoemulsification

BACKGROUND

To assess the corneal endothelium, central corneal thickness and the factors associated with endothelial cell damage after phacoemulsification in diabetics in comparison with non-diabetics.

METHODS

It was a case control study with 80 eyes each in the diabetic group and the control group. Intraoperative mydriasis, effective phaco time (EPT) and postoperative inflammation were measured. Preoperative, 1^st week, 6^th week and 3^rd month postoperative endothelial cell density (ECD), coefficient of variation (CV), hexagonality and central corneal thickness (CCT) were also measured using Konan noncon robo specular microscope (Model - NSP 9900).

RESULTS

In the control group, patients in the age group of 60-69 years were 3.8 times more at risk of ECL compared to patients in the age group of 50-59 years. Patients in whom EPT was ≥0.50 min, were 8.8 times more at risk of ECL when compared to patients in whom EPT <0.25 min. In the diabetic group, patients who had an inflammatory score of 1+ in the first postoperative week; also had 5.7 times more risk of ECL when compared to patients in whom the inflammatory score was 0.5+ in the first postoperative week. There was a significant increase in CV (p-0.03) and CCT (p-0.03), significant decrease in the hexagonality (p-0.01) and no statistically significant difference in the endothelial cell loss (ECL) (p-0.34) in diabetics after phacoemulsification when compared to controls.

CONCLUSION

The present study reveals postoperative inflammation as a risk factor for ECL in diabetics and not intraoperative mydriasis and EPT.

Medicinal Plants and Natural Products Used in Cataract Management

Cataract is the leading reason of blindness worldwide and is defined by the presence of any lens opacities or loss of transparency. The most common symptoms of cataract are impaired vision, decreased contrast sensitivity, color disturbance, and glare. Oxidative stress is among the main mechanisms involved in the development of age-related cataract. Surgery through phacoemulsification and intraocular lens implantation is the most effective method for cataract treatment, however, there are chances of serious complications and irreversible loss of vision associated with the surgery. Natural compounds consisting of antioxidant or anti-inflammatory secondary metabolites can serve as potential leads for anticataract agents. In this review, we tried to document medicinal plants and plant-based natural products used for cataract treatment worldwide, which are gathered from available ethnopharmacological/ethnobotanical data. We have extensively explored a number of recognized databases like Scifinder, PubMed, Science Direct, Google Scholar, and Scopus by using keywords and phrases such as “cataract”, “blindness”, “traditional medicine”, “ethnopharmacology”, “ethnobotany”, “herbs”, “medicinal plants”, or other relevant terms, and summarized the plants/phytoconstituents that are evaluated in different models of cataract and also tabulated 44 plants that are traditionally used in cataract in various folklore medical practices. Moreover, we also categorized the plants according to scientific studies carried out in different cataract models with their mechanisms of action.

Zinc Supplementation Ameliorates Diabetic Cataract Through Modulation of Crystallin Proteins and Polyol Pathway in Experimental Rats

Non-enzymatic glycation of lens proteins and elevated polyol pathway in the eye lens have been the characteristic features of a diabetic condition. We have previously reported the benefits of zinc supplementation in reducing hyperglycemia and associated metabolic abnormalities and oxidative stress in diabetic rats. The current study explored whether zinc supplementation protects against cataractogenesis through modulation of glycation of lens proteins, elevated polyol pathway, oxidative stress, and proportion of different heat shock proteins in the eye lens of diabetic rats. Streptozotocin-induced diabetic rats were fed with a zinc-enriched diet (5 and 10 times of normal) for 6 weeks. Supplemental zinc alleviated the progression and maturation of diabetes-induced cataract. Zinc was also effective in preventing the reduced content of total and imbalanced proportion of soluble proteins in the lens. Supplemental zinc also alleviated cross-linked glycation and concomitant expression of the receptor of glycated products and oxidative stress indicators in the eye lens. Zinc supplementation further induced the concentration of heat shock protein in the eye lens of diabetic rats, specifically α-crystallin. Zinc supplementation counteracted the elevated activity and expression of polyol pathway enzymes and molecules in the lens. The results of this animal study endorsed the advantage of zinc supplementation in exerting the antiglycating influence and downregulating polyol pathway enzymes to defer cataractogenesis in diabetic rats.

Rapidly progressive cataract formation associated with non-small-cell lung cancer therapy

We report 6 patients who developed rapidly progressive hypermature cataracts after starting treatment with rociletinib, a non-small-cell lung cancer therapy with known side effects of hyperglycemia, fatigue, and prolonged QT. Early cataract detection and surgery may prevent complications during future cataract removal. Although rociletinib development has been suspended, there are patients who have been treated and will continue to be treated with this medication based on their physician's judgment. These physicians should know about the potential for rapid vision loss due to cataracts as a manageable side effect.

FINANCIAL DISCLOSURE

Neither author has a financial or proprietary interest in any material or method mentioned.

Cataract surgery in diabetes mellitus: A systematic review

India is considered the diabetes capital of the world, and a significant proportion of patients undergoing cataract surgery are diabetic. Considering this, we reviewed the principles and guidelines of managing cataract in patients with diabetes. The preoperative, intraoperative, and postoperative factors are of paramount importance in the management of diabetic cataract patients. Particularly, the early recognition and treatment of diabetic retinopathy or maculopathy before cataract surgery influence the final visual outcome and play a major role in perioperative decision-making. Better understanding of various factors responsible for favorable outcome of cataract surgery in diabetic patients may guide us in better overalll management of these patients and optimizing the results.

The influence of low temperature and diapause phase on sugar and polyol content in the European corn borer Ostrinia nubilalis (Hbn.)

The European corn borer (ECB, Ostrinia nubilalis Hbn.) is a major pest in temperate regions of Europe and North America. Fifth instar ECB larvae enter diapause before winter and gradually develop cold hardiness. Here we investigated the combined influence of diapause phase and low temperature on sugar and polyol content in ECB larvae. Larvae in mid-diapause or diapause termination were acclimated at 5 °C, -3°C or -16 °C, and sugar and polyol content was measured using GC-MS. Control GC-MS measurements were conducted on untreated non-diapausing larvae. We detected differences in polyol (glycerol, sorbitol, myo-inositol) and sugar (trehalose, fructose, glucose) levels in diapausing versus non-diapausing larvae. Glycerol and trehalose were the most abundant of all analyzed cryoprotective compounds in diapausing larvae. Exposure of diapausing larvae to decreasing temperatures induced changes in polyol and sugar levels that depended on the phase of diapause. In mid-diapause larvae, decreasing temperatures induced a significant increase in glycerol and a decrease in sorbitol and myo-inositol. In larvae at diapause termination, polyol content was lower and less influenced by decreasing temperatures. In contrast, sugar levels were lower in larvae at mid-diapause versus diapause termination. Exposure of larvae to -16 °C induced a significant increase in the levels of all detected sugars. In particular, glucose levels were significantly higher in larvae at diapause termination following exposure to -16 °C. We propose that this shift toward sugar synthesis following low temperature exposure in larvae at diapause termination is a consequence of NADPH dependent polyol synthesis, and may be a mechanism for preservation of carbon reserves needed for post-diapause development.

The role of declining adaptive homeostasis in ageing

Adaptive homeostasis is "the transient expansion or contraction of the homeostatic range for any given physiological parameter in response to exposure to sub-toxic, non-damaging, signalling molecules or events, or the removal or cessation of such molecules or events" (Davies, 2016). Adaptive homeostasis enables biological systems to make continuous short-term adjustments for optimal functioning despite ever-changing internal and external environments. Initiation of adaptation in response to an appropriate signal allows organisms to successfully cope with much greater, normally toxic, stresses. These short-term responses are initiated following effective signals, including hypoxia, cold shock, heat shock, oxidative stress, exercise-induced adaptation, caloric restriction, osmotic stress, mechanical stress, immune response, and even emotional stress. There is now substantial literature detailing a decline in adaptive homeostasis that, unfortunately, appears to manifest with ageing, especially in the last third of the lifespan. In this review, we present the hypothesis that one hallmark of the ageing process is a significant decline in adaptive homeostasis capacity. We discuss the mechanistic importance of diminished capacity for short-term (reversible) adaptive responses (both biochemical and signal transduction/gene expression-based) to changing internal and external conditions, for short-term survival and for lifespan and healthspan. Studies of cultured mammalian cells, worms, flies, rodents, simians, apes, and even humans, all indicate declining adaptive homeostasis as a potential contributor to age-dependent senescence, increased risk of disease, and even mortality. Emerging work points to Nrf2-Keap1 signal transduction pathway inhibitors, including Bach1 and c-Myc, both of whose tissue concentrations increase with age, as possible major causes for age-dependent loss of adaptive homeostasis.

Expression of SIRT1 and P53 in Rat Lens Epithelial cells in Experimentally Induced DM

PURPOSE

To determine the etiopathogenesis of diabetic cataract by studying changes in relative expressions of silent information regulator protein-1 (SIRT1) and P53 in rat lens epithelial cells (LECs) in experimentally induced diabetes mellitus (DM).

METHODS

Six-week-old male SD rats (n = 120) were randomly divided into experimental (n = 80 rats) and control (n = 40 rats) groups. DM was induced in the experimental group (diabetic model) by intraperitoneal (i.p.) injection of 60 mg/kg streptozotocin (STZ). Control group rats were injected similarly with phosphate-buffered saline (PBS). Four and eight weeks after successful induction of DM, relative expressions of SIRT1 and P53 in LECs were analyzed using quantitative real-time (qRT) fluorescence polymerase chain reaction (qRT-PCR) and Western blot analysis.

RESULTS

Expression of both SIRT1 and P53 was observed in LECs of control and experimental group rats at 4 and 8 weeks but was significantly greater in experimental compared with control group rats (p < 0.05).

CONCLUSIONS

Expression of both SIRT1 and P53 increases in the early stages of diabetic cataract formation, indicating that they play potentially important roles in the pathogenesis of diabetic cataract.

Proteomic profile of the lens in a streptozotocin-induced diabetic rat model using shotgun proteomics

Streptozotocin (STZ)-induced diabetic rats (STZ rats) were used to investigate diabetic cataracts. In the current study, a shotgun liquid chromatography (LC)/mass spectrometry (MS)-based global proteomic analysis method was used to examine the mechanism of lens opacification as a result of hyperglycemia in STZ rats. The 6-week old Wistar rats were injected with STZ for 2 days (100 mg/kg/day, i.p.) and housed for 3 weeks. The plasma glucose levels were identified to be significantly higher when compared with the normal rats and insulin was not detected in the STZ rats. Furthermore, opacification of the cortical epithelium was observed in the lenses of STZ rats. A total of 235 proteins were identified in the lenses of the STZ rats and 229 in the lenses of the normal rats. A label-free semi-quantitative method, based on spectral counting, identified 52 proteins that were differentially expressed in the lenses of STZ rats compared with normal rats. In particular, superoxide dismutase, which is a critical antioxidant enzyme that detoxifies superoxide through redox cycling, was downregulated when analyzed by the semi-quantitative method. In addition, phosphorylated-p38, which is important in the signaling pathway involved in the oxidative stress response, was significantly increased in the lenses of STZ rats when compared with normal rats (P<0.05). Thus, the changes in protein expression were evaluated in the lenses of STZ rats using a shotgun LC/MS-based global proteomic analysis approach, and a decrease in antioxidant enzymes and an increase in oxidative stress were identified in the lenses of STZ rats. Further studies are required to examine the role of these proteins in the onset or progression of diabetic cataracts.

Age-related changes in the kinetics of human lenses: prevention of the cataract

The crystalline lens is a transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina and, by changing shape, it adjusts focal distance (accommodation). The three classes of structural proteins found in the lens are α, β, and γ crystallins. These proteins make up more than 90% of the total dry mass of the eye lens. Other components which can be found are sugars, lipids, water, several antioxidants and low weight molecules. When ageing changes occur in the lens, it causes a gradual reduction in transparency, presbyopia and an increase in the scattering and aberration of light waves as well as a degradation of the optical quality of the eye. The main changes that occur with aging are: 1) reduced diffusion of water from the outside to the inside of the lens and from its cortical to its nuclear zone; 2) crystalline change due to the accumulation of high molecular weight aggregates and insoluble proteins; 3) production of advanced glycation end products (AGEs), lipid accumulation, reduction of reduced glutathione content and destruction of ascorbic acid. Even if effective strategies in preventing cataract onset are not already known, good results have been reached in some cases with oral administration of antioxidant substances such as caffeine, pyruvic acid, epigallocatechin gallate (EGCG), α-lipoic acid and ascorbic acid. Furthermore, methionine sulfoxide reductase A (MSRA) over expression could protect lens cells both in presence and in absence of oxidative stress-induced damage. Nevertheless, promising results have been obtained by reducing ultraviolet-induced oxidative damage.

Investigation of synergistic mechanism and identification of interaction site of aldose reductase with the combination of gigantol and syringic acid for prevention of diabetic cataract

BACKGROUND

Gigantol and syringic acid (SA) have been shown to synergistically prevent formation of diabetic cataract (DC). However, the exact mechanism of this effect is unknown. Here, we investigate the effect of these compounds on the activity of aldose reductase (AR) and cataract formation.

METHODS

We examined the synergistic anti-cataract efficacy of gigantol and SA in the high glucose- and streptozotocin -induced DC rat model; synergism was evaluated using Jin's formula. We investigated possible mechanisms of action by measuring AR expression and activity and levels of sorbitol using enzyme kinetics, Western blot, and RT-PCR. Finally, we examined binding interaction between AR and both compounds using a combination of site-directed mutagenesis, recombinant expression of wild-type and mutant proteins, and enzyme kinetics.

RESULTS

Combination treatment of gigantol and SA synergistically protected both HLECs(human lens epithelial cells) grown in vitro and DC formation in STZ-induced rats in vivo. Synergism was attributed to inhibition of AR activity, downregulation of AR expression via impaired transcription, and decreased sorbitol levels. Enzyme kinetics studies showed that the activity of an AR Asn160Ala mutant protein was significantly decreased compared to wild-type AR, confirming that Asn160 is a key residue for interaction between AR and both compounds.

CONCLUSION

Combined administration of gigantol and SA synergize to enhance anti-cataract efficacy. The synergistic effect is mainly attributed to disruption of the polyol pathway and inhibition of AR activity.

Melatonin Reduces Cataract Formation and Aldose Reductase Activity in Lenses of Streptozotocin-induced Diabetic Rat

BACKGROUND

The relationship between the high activity of aldose reductase (AR) and diabetic cataract formation has been previously investigated. The purpose of the present study was to determine the preventing effect of melatonin on streptozotocin (STZ)-induced diabetic cataract in rats.

METHODS

34 adult healthy male Sprague-Dawely rats were divided into four groups. Diabetic control and diabetic+melatonin received a single dose of STZ (50 mg/kg, intraperitoneally), whereas the normal control and normal+melatonin received vehicle. The melatonin groups were gavaged with melatonin (5 mg/kg) daily for a period of 8 weeks, whereas the rats in the normal control and diabetic control groups received only the vehicle. The rats' eyes were examined every week and cataract formation scores (0-4) were determined by slit-lamp microscope. At the end of the eighth week, the rats were sacrificed and markers of the polyol pathway and antioxidative (Glutathione, GSH) in their lens were determined. The levels of blood glucose, HbA1c and plasma malondialdhyde (MDA), as a marker of lipid peroxidation, were also measured.

RESULTS

Melatonin prevented STZ-induced hyperglycemia by decreased blood glucose and HbA1c levels. Slit lamp examination indicated that melatonin delayed cataract progression in diabetic rats. The results revealed that melatonin feeding increased the GSH levels, decreased the activities of AR and sorbitol dehydrogenase (SDH) and sorbitol formation in catractous lenses as well as plasma MDA content.

CONCLUSION

In summary, for the first time we demonstrated that melatonin delayed the formation and progression of cataract in diabetic rat lenses.

Featured Article: Inhibition of diabetic cataract by glucose tolerance factor extracted from yeast

Diabetes leads to many complications; among them is the development of cataract. Hyperglycemia brings to increased polyol concentration in the lens, to glycation of lens proteins, and to elevated level of ROS (Reactive Oxygen Species) causing oxidative stress. The glucose tolerance factor (GTF) was found by several groups to decrease hyperglycemia and oxidative stress both in diabetic animals and humans. The aim of our study was to explore the damages induced by high glucose to the eye lens and to assess the protective effects of GTF both in vivo and in vitro The in vivo study included control healthy rats, streptozotocin (STZ) diabetic untreated rats, and STZ diabetic rats orally treated with 15 doses of GTF. The diabetic untreated rats developed cataracts, whereas the development of cataract was totally or partially prevented in GTF treated animals. In vitro studies were done on bovine lenses incubated for 14 days. Half of the lenses were incubated in normal glucose conditions, and half in high glucose conditions (450 mg%). To one group of the normal or high glucose condition GTF was added. The optical quality of all the lenses was measured daily by an automated scanning laser system. The control lenses, whether with or without GTF addition, did not show any reduction in their quality. High glucose conditions induced optical damage to the lenses. Addition of GTF to high glucose conditions prevented this damage. High glucose conditions affected the activity of aldose reductase and sodium potassium ATPase in lens epithelial cell. Addition of GTF decreased the destructive changes induced by high glucose conditions. The amount of soluble cortical lens proteins was decreased and structural changes were detected in lenses incubated in high glucose medium. These changes could be prevented when GTF was added to high glucose medium. Our findings demonstrate the anticataractogenic potential of GTF.

Visual impairment and blindness in type 2 diabetics: Ife-Ijesa diabetic retinopathy study

Diabetes and blindness are important health issues globally; we determined the prevalence of blindness, diabetic retinopathy, and other eye diseases in Nigerian-type 2 diabetics. A prospective, cross-sectional study was conducted on consenting type 2 diabetic patients who had scheduled comprehensive eye examination including dilated funduscopy with +78DS. Visual status was graded using the WHO criteria. Approval from Institutional Ethics Committee was obtained. Primary outcome measures were the prevalence and causes of blindness as well as prevalence of diabetic retinopathy. Secondary outcome measures were the presence of other eye diseases. Data were analyzed using SPSS version 13. Two hundred and sixty-six eyes of 133 type 2 diabetic patients aged 22-89 years were studied; 69 (51.9 %) were males while 64 (48.1 %) were females. Five (3.8 %) patients were blind while 27 (20.3 %) were visually impaired. Cataract was the leading cause of blindness (60 %) and visual impairment was found in 59.3 %. Diabetic retinopathy was present in 37 (27.8 %) diabetic patients of which 5 (3.8 %) were proliferative. Diabetic macular edema was present in 31 (23.3 %) patients. Severe visual impairment and blindness were commoner in those with diabetic retinopathy. Refractive error 67 (25.2 %), cataract 63 (23.7 %), and chronic glaucoma 44 (16.5 %) were the most prevalent non-diabetic retinopathy eye diseases. High prevalence of blindness, diabetic retinopathy, and other diseases are seen in type 2 diabetics. Health education, early diagnosis as well as treatment of diabetic retinopathy and other diseases will largely alleviate these ocular morbidities.

Anti-osmotic and antioxidant activities of gigantol from Dendrobium aurantiacum var. denneanum against cataractogenesis in galactosemic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium aurantiacum var. denneanumis widespread in southern China, locally known as "Shihu", "Huangcao" or "Fengdou", has long been used in traditional Chinese medicine for antipyretic, immunomodulatory, anti-aging effects and eye benefiting.

AIM OF THIS STUDY

To investigate the effects of gigantol extracted from the stem of D. aurantiacum var. denneanum on the formation of galactose-induced cataractogenesis and the potential mechanisms underlying these effects.

MATERIALS AND METHODS

Cataract lens models were induced by d-galactose both in vitro and in vivo. The transparency of the rat lenses in vitro and in vivo was observed with an anatomical microscope and a slit lamp microscope. The differential protein and action targets of gigantol were determined and compared among the control group, model group, and gigantol group using two-dimensional electrophoresis and mass spectrometry (MS). Enzyme kinetics was used to show the ability of gigantol to respress aldose reductase (AR) and inducible nitric oxide synthase (iNOS). Quantitative real-time PCR (RT-qPCR). was used to detect repression of the expression of AR and iNOS genes. Molecular docking and dynamic simulation were used to predict the interaction points and combination patterns between gigantol, AR, and iNOS.

RESULTS

Gigantol was found to prevent galactose-induced damage to the rat lenses both in vitro and in vivo, to delay lens turbidity, and to keep the lenses transparent. Differential proteomes, MS, and RT-qPCR showed AR and iNOS to be the target proteins of gigantol. Gigantol reduced the galactose-induced AR and iNOS mRNA expression by 51.2% and 60.9%, respectively. The IC50 of gigantol for inhibition of AR and iNOS activities were 65.67 μg/mL and 8.768 μg/mL, respectively. Gigantol-AR binding sites were Trp111, His110, Tyr48, and Trp20, and gigantol-iNOS binding sites were Ile195 and Gln257. The main forms of interaction were hydrophobic forces, hydrogen bonds, and van der Waals forces.

CONCLUSION

Gigantol extracted from D. aurantiacum var. denneanum was found to inhibit galactose-induced formation of cataracts through repression of the gene expression and activity of AR and iNOS.

Hypercholesterolemia-induced ocular disorder: Ameliorating role of phytotherapy

The ocular region is a complex structure that allows conscious light perception and vision. It is of ecto-mesodermal origin. Cholesterol and polyunsaturated fatty acids are involved in retinal cell function; however, hypercholesterolemia and diabetes impair its function. Retinal damage, neovascularization, and cataracts are the main complications of cholesterol overload. Dietary supplementation of selected plant products can lead to the scavenging of free reactive oxygen species, thereby protecting the ocular regions from the damage of hypercholesterolemia. This review illustrates the dramatic effects of increased cholesterol levels on the ocular regions. The effect of phytotherapy is discussed in relation to the different regions of the eye, including the retina, cornea, and lens.

Free radicals: properties, sources, targets, and their implication in various diseases

Free radicals and other oxidants have gained importance in the field of biology due to their central role in various physiological conditions as well as their implication in a diverse range of diseases. The free radicals, both the reactive oxygen species (ROS) and reactive nitrogen species (RNS), are derived from both endogenous sources (mitochondria, peroxisomes, endoplasmic reticulum, phagocytic cells etc.) and exogenous sources (pollution, alcohol, tobacco smoke, heavy metals, transition metals, industrial solvents, pesticides, certain drugs like halothane, paracetamol, and radiation). Free radicals can adversely affect various important classes of biological molecules such as nucleic acids, lipids, and proteins, thereby altering the normal redox status leading to increased oxidative stress. The free radicals induced oxidative stress has been reported to be involved in several diseased conditions such as diabetes mellitus, neurodegenerative disorders (Parkinson's disease-PD, Alzheimer's disease-AD and Multiple sclerosis-MS), cardiovascular diseases (atherosclerosis and hypertension), respiratory diseases (asthma), cataract development, rheumatoid arthritis and in various cancers (colorectal, prostate, breast, lung, bladder cancers). This review deals with chemistry, formation and sources, and molecular targets of free radicals and it provides a brief overview on the pathogenesis of various diseased conditions caused by ROS/RNS.

Anti-Diabetic and Anti-Inflammatory Effects of Green and Red Kohlrabi Cultivars (Brassica oleracea var. gongylodes)

The aim of the present study was to evaluate the anti-diabetic, anti-inflammatory, antioxidant potential, and total phenolic content (TPC) of green and red kohlrabi cultivars. Anti-diabetic and anti-inflammatory activities were evaluated via protein tyrosine phosphatase (PTP1B) and rat lens aldose reductase inhibitory assays and cell-based lipopolysaccharide (LPS)-induced nitric oxide (NO) inhibitory assays in RAW 264.7 murine macrophages. In addition, scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical, and peroxynitrite (ONOO⁻) were used to evaluate antioxidant potential and TPC was selected to assess phytochemical characteristics. Between the two kohlrabi cultivars, red kohlrabi (RK) had two times more TPC than green kohlrabi (GK) and showed significant antioxidant effects in DPPH, ABTS, and ONOO⁻ scavenging assays. Likewise, methanol (MeOH) extracts of RK and GK inhibited LPS-induced NO production in a dose dependent manner that was further clarified by suppression of iNOS and COX-2 protein production. The MeOH extracts of RK and GK exhibited potent inhibitory activities against PTP1B with the corresponding IC₅₀ values of 207±3.48 and 287±3.22 μg/mL, respectively. Interestingly, the RK MeOH extract exhibited significantly stronger anti-inflammatory, anti-diabetic, and antioxidant effects than that of GK MeOH extract. As a result, our study establishes that RK extract with a higher TPC might be useful as a potent anti-diabetic, antioxidant, and anti-inflammatory agent.

An increase in phosphorylation and truncation of crystallin with the progression of cataracts

Background

Cataracts are the leading cause of blindness worldwide; however, there is no evidence regarding the direct formation of cataracts. At present, there is no treatment method other than surgery to prevent the formation or progression of cataracts.

Objective

Understanding the protein changes during various stages of cataracts might help realize the mechanism of the formation and progression of cataracts.

Methods

Lens materials were collected from cataract surgery. Cataracts were classified according to lens opacity using the gradation of the Lens Opacities Classification System. Lens proteins were separated by 2-dimensional polyacrylamide gel electrophoresis. Protein spots were visualized by Coomassie blue staining, and expression patterns were analyzed. Protein spots of interest were excised from 2-dimensional polyacrylamide gel electrophoresis gels, digested in situ with trypsin, and analyzed by mass spectrometry and liquid chromatographic tandem mass spectrometry.

Results

Crystallin was the major protein in the cataract lens, and αA, βB1, αB, and βA4 were the dominant types. Crystallin αB and βA4 increased with the formation of lens opacity. Moreover, phosphorylation and truncation of these proteins increased with the progression of cataracts.

Conclusion

Crystallin αB and βA4 and phosphorylation and truncation of crystallin in the lens might contribute to the formation of cataracts. In contrast, acetylation was not dominant in the progression of cataracts and did not play major role in the formation of cataracts.

Inhibitory effect of r-hirudin variant III on streptozotocin-induced diabetic cataracts in rats

The in vivo inhibitory effect of r-hirudin variant III (rHV3) on streptozotocin (STZ)-induced diabetic cataracts in rats was investigated. SD-rats were firstly made diabetic by a single intraperitoneal injection of 2% (W/V) STZ (65 mg/kg). Two weeks later, cataract formation was examined by slit lamp microscope, and the cataracted animals were randomly grouped. The animals in the treated groups received rHV3 drops administration to the eyes with various doses. After 4 weeks treatment, the animals were sacrificed to evaluate the biochemical changes of aldose reductase (AR), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) levels in the eye lens. Meanwhile, the cataract progression was monitored by slit lamp microscope. As a result, rHV3 drops treatment significantly increased the activities of SOD and GSH-Px in the lens in a dose-dependent manner, whereas AR activity and MDA level in the lens were dramatically decreased. Also, the morphological observation further confirmed the inhibition of the development of STZ-induced diabetic cataracts by the rHV3 drops treatment. Thus, our data suggest that rHV3 drops are pharmacologically effective for the protection against STZ-induced diabetic cataracts in rats.

Diabetic cardiomyopathy: Pathophysiology, diagnostic evaluation and management

Diabetes affects every organ in the body and cardiovascular disease accounts for two-thirds of the mortality in the diabetic population. Diabetes-related heart disease occurs in the form of coronary artery disease (CAD), cardiac autonomic neuropathy or diabetic cardiomyopathy (DbCM). The prevalence of cardiac failure is high in the diabetic population and DbCM is a common but underestimated cause of heart failure in diabetes. The pathogenesis of diabetic cardiomyopathy is yet to be clearly defined. Hyperglycemia, dyslipidemia and inflammation are thought to play key roles in the generation of reactive oxygen or nitrogen species which are in turn implicated. The myocardial interstitium undergoes alterations resulting in abnormal contractile function noted in DbCM. In the early stages of the disease diastolic dysfunction is the only abnormality, but systolic dysfunction supervenes in the later stages with impaired left ventricular ejection fraction. Transmitral Doppler echocardiography is usually used to assess diastolic dysfunction, but tissue Doppler Imaging and Cardiac Magnetic Resonance Imaging are being increasingly used recently for early detection of DbCM. The management of DbCM involves improvement in lifestyle, control of glucose and lipid abnormalities, and treatment of hypertension and CAD, if present. The role of vasoactive drugs and antioxidants is being explored. This review discusses the pathophysiology, diagnostic evaluation and management options of DbCM.

Development of aldose reductase inhibitors for the treatment of inflammatory disorders

INTRODUCTION

Accumulating evidence attributes a significant role to aldose reductase (ALR2) in the pathogenesis of several inflammatory pathologies. Aldose reductase inhibitors (ARIs) were found to attenuate reactive oxygen species (ROS) production both in vitro and in vivo. Thus, they disrupt signaling cascades that lead to the production of cytokines/chemokines, which induce and exacerbate inflammation. As a result, ARIs might hold a significant therapeutic potential as alternate anti-inflammatory drugs.

AREAS COVERED

The authors present a comprehensive review of the current data that support the central role of ALR2 in several inflammatory pathologies (i.e., diabetes, cancer, sepsis, asthma and ocular inflammation). Further, the authors describe the potential underlying molecular mechanisms and provide a commentary on the status of ARIs in this field.

EXPERT OPINION

It is important that future efforts focus on delineating all the steps of the molecular mechanism that implicates ALR2 in inflammatory pathologies. At the same time, utilizing the previous efforts in the field of ARIs, several candidates that have been proven safe in the clinic may be evaluated for their clinical significance as anti-inflammatory medication. Finally, structurally novel ARIs, designed to target specifically the proinflammatory subpocket of ALR2, should be pursued.

Ocular disease, knowledge and technology applications in patients with diabetes

An estimated 25.8 million children and adults in the United States, approximately 8.3% of the population, have diabetes. Diabetes prevalence varies by race and ethnicity. African Americans have the highest prevalence (12.6%), followed closely by Hispanics (11.8%), Asian Americans (8.4%) and whites (7.1%). The purpose of this article was to discuss the ocular complications of diabetes, the cultural and racial differences in diabetes knowledge and the role of telemedicine as a means to reach the undeserved who are at risk of complications. Information on the pathophysiology of ocular disease in patients with diabetes and the role of telemedicine in diabetes care was derived from a literature review. National Institutes of Health online resources were queried to present data on the racial and cultural understandings of diabetes and diabetes-related complications. The microvascular ocular complications of diabetes are discussed for retinopathy, cataracts, glaucoma and ocular surface disease. Racial and cultural differences in knowledge of recommended self-care practices are presented. These differences, in part, may explain health disparities and the increased risk of diabetes and its complications in rural minority communities. Finally, advances in telemedicine technology are discussed that show improvements in metabolic control and cardiovascular risk in adults with type 2 diabetes. Improving provider and patient understanding of diabetes complications may improve management and self-care practices that are important for diabetes control. Telemedicine may improve access to diabetes specialists and may improve self-management education and diabetes control particularly in rural and underserved communities.