Anti-cataract Agent Research Articles

Possibilities of Conservative Treatment and Prevention of Cataract Development Using an Anti-cataract Drug

The priority directions of the state policy of the Russian Federation are medical and preventive measures related to the physical and social improvement of the country’s population. These measures are aimed at improving the quality and effectiveness of medical rehabilitation activities and at reducing the morbidity and disability of various groups of patients. Clouding of the lens (cataract) is very different in terms of time of occurrence, localization, flow and is always accompanied by weakening of vision. Existing theories explain the pathogenesis of cataracts by the general state of the body (dysfunction of the glands of internal secretion, hidden tetany, violation of the functions of the autonomic nervous system, main exchange, etc.), unfavorable heredity, negative external influences, etc.The results of various studies strongly show that Quinax (azapentacen 5,12-dihydroazapentacene sodium disulfonate), 0.015 %, is an anticataract agent on all layers of the lens. In 2023, PROFIT-PHARM (PROFIT-PHARM LLC) developed domestic Quinax eye drops. It is necessary to conduct a study of their clinical effectiveness in patients with various types of cataracts, as well as to prevent its occurrence.

Development of rapid analysis of eye drops for monitoring during various technological operations

In this article, the composition and technology of combined eye drops were developed, including taurine as an anti-cataract agent and betaxolol hydrochloride as an anti-glaucoma agent. Butanol, toluene, isopropyl ether, chloroform, ammonia 25%, ethyl alcohol in various ratios were used as the mobile phase. However, these solutions and their combinations did not allow us to determine a system that makes it possible to register both active components simultaneously. Therefore, it was decided to select two thin layer chromatography systems, one of which made it possible to determine taurine, and the other betaxolol hydrochloride

Investigation of Novel Nanoplatforms for Delivery of an Anticataract Drug in Whole Lens Cultures

Cataracts are a leading cause of blindness, but the only available treatment is surgery, which may not be a viable option for many patients. Instead, pharmacological interventions that target cataractogenesis at the molecular level represent an attractive method for preventing or delaying cataract formation. Antioxidant drugs like N-(2-mercaptopropionyl)glycine may interfere with oxidative processes that lead to age-related nuclear cataracts. Nevertheless, achieving therapeutic concentrations in the lens has proven challenging. Novel delivery strategies such as functionalized nanodiamonds offer several advantages over conventional platforms in terms of stability and customizability. Therefore, we investigated the effects of three different types of functionalized nanodiamonds on the uptake and efficacy of a potential anticataract agent in a whole organ culture model of oxidative insult in the lens. Lenses treated with sodium selenite exhibited detrimental morphological changes and significantly deteriorated redox status. Lenses treated with the neat drug showed marked improvements. However, only hydroxylated nanodiamonds appeared to improve drug uptake, and their effects on lens glutathione and cysteine were modest. This work represents a critical step in understanding the anticataract effects of N-(2-mercaptopropionyl)glycine, and it suggests that other drug delivery strategies may be warranted to realize these effects in vivo.

Protective Effects of Safranal Against Selenite-Induced Cataract in Rats

Cataract, which is the opacity inside clear ocular lens of eye, result in the scattering of visible light as it passes via the lens and consequently deterioration in optical image. The aim of the present study was to investigate whether safranal, an active constituent of Crocus sativus L. stigmas, has a protective effect on the cataract in the rat's pups. The animals were randomly divided into five groups, each of which consisted of 7 rat pups. Group I served as normal control (vehicle administration). For testing cataract induction, animals of Groups II, III, and IV were administered a single subcutaneous injection of sodium selenite on postpartum day 12. After sodium selenite intoxication, Group II served as control selenite, Groups III-IV received intraperitoneal safranal at doses of 200, and 300 mg/kg, respectively from the 11th day through the 17th day, while group V receive only safranal (300 mg/kg). On postpartum day 30, the rat pups were examined for cataract formation, and the lenses were isolated for further analysis. This study found that selenite caused significant (p < 0.05) cataract formation. Through the effects of selenite on the level of lipid peroxidation (MDA) which was upregulated. Furthermore, the antioxidant enzymes levels GSH levels and NRF2 protein were downregulated. In contrast, treatment with safranal could significantly (p < 0.05) ameliorate cataract formation and oxidative damage in the lens. Moreover, safranl administration significantly increased the protein expressions of Nrf2 and the GSH level, in addition to reducing the level both the MDA and the level soluble proteins in the lens. Taken together, safranal is a prospective anti-cataract agent that probably delays the onset and progression of cataracts induced by sodium selenite.

Standardization of a new method for assessing the development of cataract in cultured bovine lenses

PurposeTo standardize a new method for assessing cataractogenesis in isolated cultured bovine lenses using L-cysteine as the standard anti-cataract agent. MethodsIntact bovine lenses were cultured in DMEM with L-cysteine in presence or absence of hydrogen peroxide (H2O2). Lens opacity (transmittance) was determined using a plate reader. Lens homogenate glutathione (GSH) and superoxide dismutase (SOD) contents were measured using enzyme immunoassays kits. ResultsDMEM-cultured lenses exhibited a time-dependent loss in transmittance (230–710 nm) up to 120 h, achieving the highest reduction of 38.6 ± 0.09% at 420 nm (p < .001;n = 12). Compared to untreated lenses (time in hours [t] = 0), L-cysteine (10−6 M and 10−5 M) significantly (p < .001;n = 6) increased time-dependent transmittance (420 nm) by 31.6 ± 0.17% and 28.0 ± 0.07%(t = 120), respectively. When compared to DMEM-cultured lenses (t = 0), H2O2 (10 mM, 50 mM and 100 mM) significantly (p < .001;n = 12) reduced transmittance by 57.8 ± 0.1, 57.4 ± 0.04 and 87.7 ± 0.6%(t = 120), respectively. Moreover, L-cysteine significantly (p < .001;n = 6) attenuated H2O2 (50 mM)-induced decrease in transmittance by 12.5 ± 0.05%(10−6 M), 13.0 ± 0.09%(10−5 M), 14.5 ± 0.08%(10−4 M) and 8.6 ± 0.11%(10−3 M)(t = 120), respectively.When compared to untreated lenses (t = 0), the time-dependent decrease (p < .001;n = 5) in lenticular total GSH content and total SOD activity of 46.1 ± 0.06% and 42.0 ± 1.65% (t = 120) was attenuated (p < .001;n = 5) by L-cysteine (10−6 M) by 76.6 ± 0.06% and 7.4 ± 1.98%, respectively. Similarly, the H2O2(50 mM)-induced decline (p < .001; n = 5) in total GSH content and SOD activity of 82.6 ± 0.08% and 86.6 ± 0.66% (t = 120) was attenuated by L-cysteine (10−4 M) by 74.7 ± 1.05% and 161.1 ± 4.9%, respectively. ConclusionMeasurement of spectral transmission coupled with assessment of the activity of antioxidant enzymes in bovine cultured lens can provide a useful tool in studies of cataracts in an animal model of this disease.

Protective Effects of Rosmarinic Acid against Selenite-Induced Cataract and Oxidative Damage in Rats.

Cataracts are the major cause of blindness and are associated with oxidative damage of the lens. In the present study, the aim was to evaluate the protective effects of rosmarinic acid on selenite-induced cataractogenesis in Sprague-Dawley rat pups. The animals were randomly divided into five groups, each of which consisted of 10 rat pups. Group I served as normal control (vehicle administration). For testing cataract induction, animals of Groups II, III, IV, and V were administered a single subcutaneous injection of sodium selenite (2.46 mg/kg body weight) on postpartum day 12. After sodium selenite intoxication, Group II served as control selenite. From the 11th day through the 17th day, Groups III-V received rosmarinic acid intraperitoneally at doses of 5, 10, and 50 mg/kg, respectively. On postpartum day 24, the rat pups were examined for cataract formation, and the lenses were isolated for further analysis of proteins and oxidative damage indicators. Selenite caused significant (p < 0.05) cataract formation. Through the effects of selenite, the protein expressions of filensin and calpain 2 were reduced, and the calcium concentrations, the level of lipid peroxidation (TBARS), and inflammation indicators (iNOS, COX-2, and NFκB) were upregulated. Furthermore, the protein expression of the antioxidant status (Nrf2, SOD, HO-1, and NQO1), the antioxidant enzymes activities (GSH-Px, GSH-Rd, and catalase), and the GSH levels were downregulated. In contrast, treatment with rosmarinic acid could significantly (p < 0.05) ameliorate cataract formation and oxidative damage in the lens. Moreover, rosmarinic acid administration significantly increased the protein expressions of filensin, calpain 2, Nrf2, SOD, HO-1, and NQO1, the antioxidant enzymes activities, and the GSH level, in addition to reducing the calcium, lipid peroxidation, and inflammation indicators in the lens. Taken together, rosmarinic acid is a prospective anti-cataract agent that probably delays the onset and progression of cataracts induced by sodium selenite.

Preparation, in vitro Characterization and Pharmacokinetic Study of Coenzyme Q10 Long-Circulating Liposomes.

Long-circulating liposomal delivery systems of encapsulated Coenzyme Q10 (CoQ10), a ubiquinone anti-cataract agent, were developed with different molar ratios of PEGylated lipids and/or cholesterol. The resulting samples were contrasted through observation of morphology, analysis of particle size and Zeta potential, and in vivo pharmacokinetics. A protamine aggregation method with high selectivity was developed to determine the encapsulation efficiency (EE), after which the liposome formulation was further optimized by applying a Box Behnken design (BBD) using EE as the evaluation index. The results showed that liposomes had a large, unilamellar structure, and that particle sizes of cholesterol-containing liposomes increased along with the increase of cholesterol molar percentage, while the size of PEGylated vesicles decreased slightly as PEG-lipid contents increasing. The optimum formulation and optimal values of each influencing factor were quantitatively obtained, and the measured value was highly consistent with the predicted results. In vivo evaluation performed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) demonstrated that liposomal encapsulation largely prolonged half-lives and improved bioavailability for vectors prepared with either lipid component, and the liposomes composed of both cholesterol and PEG-lipid possessed the best pharmacokinetic properties. The results suggest that incorporating high contents of cholesterol and PEG modification could be a potentially useful method for enhancing the length of circulation and the sustained release effect for liposome-encapsulated chemicals.

Lens Aldose Reductase Inhibitory and Free Radical Scavenging Activity of Fractions of &lt;i&gt;Chromolaena odorata&lt;/i&gt; (Siam Weed): Potential for Cataract Remediation

Searching for effective and safe aldose reductase (AR) inhibitor agent is a major thrust area in the mainstream of anti-cataractogenic research. This study was set up to investigate the in vitro aldose reductase inhibitory (ARI) activity of fractions of methanolic extract of Chromolaena odorata leaves, on partially purified AR from goat lens, for potential use in the development of anticataractogenic agent. The phyto-constituents of the leaves were screened in aqueous and methanolic extracts and the free radical scavenging activities of the fractions were evaluated. The kinetics of the enzyme in the presence of fractions of the leaves was then compared. Phenol, flavonoid, alkaloid, saponin, terpenoid, quinones and phlobatannins were detected in both extracts. All the fractions inhibited AR in an uncompetitive manner, showing a reduced V max and Km when compared with glyceraldehyde. ARI activity was found to be the highest with aqueous fraction (IC50, 0.22 ± 0.01 mg/ml). All other fractions showed mild to moderate AR inhibition capacity, while it was found to be the lowest within hexane fraction (IC50, 1.20 ± 0.10 mg/ml). All the fractions showed free radical scavenging activity and metal chelating activity. The study confirmed the ARI and antioxidant capacity of Chromolaena odorata which may be due to its phenolic constituents, indicating that the plant may serve as a base for the development of anticataract agent.

Effect of monohydroxylated flavonoids on glycation-induced lens opacity and protein aggregation

Glycation-induced cataractogenesis and visual impairment is a major ophthalmic concern of altered sugar homeostasis in humans as well as animals. Searching antiglycating agents from natural sources is widely acknowledged as it can be made bioavailable through diet. The present study was designed to understand the positional suitability of hydroxylation in the flavonoid scaffold for maneuvering it as an anticataract agent. Six naturally occurring monohydroxylated flavonoids rataining hydroxylation at 3, 5, 6, 7, 2′ and 4′ carbon position were evaluated for their effect on glycation induced lens opacity, protein aggregation, carbonyl group formation and nontryptophan fluorescence. The selected flavonoids also evaluated for their aldose reductase inhibition: a key enzyme implicated in cataractogenesis. The results of this study clearly demonstrated the stereo-specificity of hydroxyl substitution and focused the significance of 7-hydroxy substitution as a lead scaffold. Overall, the test flavonoids demonstrated considerable anti-cataract activities in context with studied parameters.

Caffeine, an in vivo oxidation protectant in the lens

SummaryThe major avoidable cause of cataract is ultraviolet radiation (UVR). We aimed at investigating topical caffeine in UVR‐induced cataract.Topical caffeine and a placebo were applied to the eyes of separate groups of Sprague Dawley rats that were exposed to sub‐doses of UVR and protective effect was evaluated. Penetration of topical caffeine in the rats to lens and blood was analysed by HPLC. Influence of topical caffeine on pupil diameter was measured in ketamine/xylazine anesthetized rats.Topically administered caffeine protected against UVR‐induced cataract development with a Protection Factor, an objective relative measure of protective properties, of 1.23 and inhibited UVR‐induced apoptosis. Topical caffeine peaked at 30 min in the lens, increased up to 120 min in the blood and antagonized ketamine/xylazine‐induced mydriasis. Eyes treated with caffeine reacted with quick dilatation after tropicamide application.In conclusion, topically applied caffeine protects against ultraviolet radiation cataract, reducing lens sensitivity 1.23 times. Considering that caffeine is a powerful antioxidant that is easily available and well tolerated our finding implicates that caffeine may be a clinically useful anticataract agent.

Phytochemical characterization and evaluation of anticataract potential of seabuckthorn leaf extract.

This study was undertaken to carry out phytochemical characterization of aqueous extract of Seabuckthorn (SBT, Hippophae rhamnoides L.) leaves and evaluation of its therapeutic role in oxidative stress-induced cataract in isolated goat lenses using Vit. E as reference compound. A total of 42 goat eye lenses were used in the present study. Seabuckthorn leaf extract was characterized by total phenol content estimation and HPLC analysis of quercetin and catechin. Further, cataract was induced in goat lenses using hydrogen peroxide (H2O2) and anticataract activity was evaluated using the extract in the dose range of 100, 200, 500, and 1000 μg/mL concentrations through estimation of biochemical markers such as superoxide dismutase (SOD), reduced glutathione (GSH), and malonaldehyde (MDA). The results of the phytochemical characterization showed the total phenol content of the extract to be 365 mg/g in terms of gallic acid equivalents. Quercetin and catechin were estimated to be 0.01 and 0.12% w/w, respectively. In biochemical analysis, H2O2 introduction resulted in a decrease in SOD (approximately 85%) and GSH (approximately 63%) contents and an increase in MDA content (approximately 300%). The decreased levels of SOD and GSH were significantly restored in experimental groups receiving 500 and 1000 1g/mL of SBT extract. All the experimental groups showed significantly reduced MDA level in all the doses. Aqueous extract of SBT leaves showed the potential to delay onset and/or progression of cataract, at least during in vitro conditions. Results indicate the possibilities of evaluating this extract for its use as anticataract agent during in vivo conditions.

Investigation of Carvedilol as an Antidenaturing and Anticataract Agent

Cataract is an opacification of the lens of eye. Causes of cataract formation are aging, generation of free radicals, diabetes, protein denaturation by oxidative stress or any inducer etc. Antioxidants and antioxidant enzymes, antidenaturing agent protect the eyes by reducing free radical damage and eye lenses by inhibiting protein denaturation. The present study evaluated the in vitro anticataract and antidenaturing activities of carvedilol against glucose-induced cataractogenesis using goat lenses and heat induced egg albumin denaturation. Transparent isolated goat lenses are incubated in artificial aqueous humor and divided into five experimental groups. The carvedilol at a dose of 20μg/ml is incubated simultaneously with glucose (55 mM) and glucose (5.5 mM) for a period of 72 h. ascorbic acid (20 μg/ml) is used as the standard drug. At the end of the incubation lense opacity is measured by photographic evaluation. Antidenaturing activity is evaluated by taking different concentration of carvedilol (10 p.p.m – 500 p.p.m) with egg albumin and subjected for protein denaturation by using heat for 15 min. Standard drug is used as Diclofenac sodium, at the end protein denaturation is analyse by taking absorbance at 440 nm and 660 nmrsp. The carvedilol shows significant inhibition of cataractogenesis of eye lenses by carvedilol at conc. 20 p.p.m. and also thermally induced protein denaturation inhibited by carvedilol at conc. 500 p.p.m. The present supports carvedilol as an antidenaturing and anticataract agent.

Corneal penetration of gold nanoparticles--therapeutic implications.

Gold nanoparticles can show anti-glycation activity thereby preventing the aggregation of proteins. As glycation is one of the leading causes of cataract formation, the finding is important in therapeutic management of ocular pathology that follows cataract formation (e.g., cortical changes often resulting in nuclear sclerosis). In the present study, we have successfully conducted in vivo experiments using guinea pig models. While the anti-glycation property of GNPs is known in vitro, the present work for the first time shows corneal penetration of GNPs. The therapeutic promise of using GNP as an anti-cataract agent thus seems imminent. GNPs traverse and get deposited into different layers of the cornea as examined by Transmission Electron Microscopy (TEM).

Acetyl-l-carnitine prevents homocysteine-induced suppression of Nrf2/Keap1 mediated antioxidation in human lens epithelial cells.

Previous studies have revealed that high levels of serum homocysteine (Hcy) are closely associated with the development of juvenile and age-related cataracts. An increased concentration of Hcy is likely to induce gene specific demethylation in DNA promoter regions. The aim of the present study was to prevent this demethylation by administering acetyl-l-carnitine (ALCAR) to human lens epithelial cells (HLECs). Different concentrations of Hcy were used to treat HLECs for 3, 6, 12 and 24 h and the findings were used to determine the optimum dose to induce endoplasmic reticulum (ER) stress. Similarly, the concentration of ALCAR was standardized. The production of reactive oxygen species (ROS) and the percentage of cells undergoing cell death were measured. The levels of antioxidants, ER stress-associated proteins, mRNA levels of nuclear factor erythroid-2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap1) and promoter DNA methylation of the Keap1 gene were also assessed. Hcy was observed to induce ER stress, produce ROS and lead to cell death. However, administration of ALCAR prevented these effects to a significant degree. Additionally, western blot analysis revealed that ALCAR increased the levels of antioxidant proteins, including catalase, superoxide dismutase, glutathione peroxidase, Nrf2, Keap1 and glutathione. Similarly, the reverse transcription-quantitative polymerase chain reaction experiments on Nrf2 and Keap1, as well as the bisulfite genomic DNA sequencing analysis revealed a preventive effect of ALCAR against Hcy-induced ER stress. The ER stress-induced activation of the unfolded protein response is responsible for demethylation of Keap1 promoter DNA to activate the expression of the Keap1 protein, which then increases the targeting of Nrf2 for proteosomal degradation. This decrease in Nrf2 activity represses the transcription of numerous antioxidant enzyme genes and alters the redox-balance towards lens oxidation. However, treatment with ALCAR led to significant protection from these effects. The present results suggested that ALCAR either prevents or ameliorates the actions of the antioxidant system in HLECs at the level of the protein and the gene. Further advanced studies are required for the development of ALCAR as an anti-cataract agent.

Anti-UVC Irradiation and Metal Chelation Properties of 6-Benzoyl-5,7-dihydroxy-4-phenyl-chromen-2-one: An Implications for Anti-Cataract Agent

Coumarin derivative 1, 5,7-dihydroxy-6-(3-methyl-1-butyryl)-4-phenyl-chromen- 2-one, has been reported to possess radical scavenging activity and DNA protection. We have synthesized a series of coumarins with structural modifications at positions C4, C5, C6 and C7 and evaluated them for their anti-UVC properties. Coumarin 7, 6-benzoyl-5,6-dihydroxy-4-phenyl-chromen-2-one, was found to have the most potent activity in protecting porcine γ-crystallin against UVC insults. Results of fluorescence assays indicated that compound 7 was capable of decreasing the loss of intensity while lens crystallins and DNA PUC19 were irradiated with UVC. Presence of compound 7 decreased hydroxyl radical levels determined by probe 1b and the free iron concentrations determined by Ferrozine reagent. The chelation assay showed that compound 7 was chelated to metal via 6-CO and 5-OH on the benzopyrone ring. The observed protective effects of compound 7 towards crystallins from insults of UVC and free radicals may be due to its iron-chelating activity and its peak absorption at 254 nm.

Potential of Allylmercaptocaptopril as an Anti Cataract Agent against Galactosemic Cataract in Rats: An in Vitro and in Vivo Studies

Aim: Allylmercaptocaptopril (AMC) is a covalently bonded product of allicin and captopril has been evaluated for its anticataract activity against selenite induced cataract in experimental animals. We wanted to evaluate its anticataract potential in galactosemic cataract to elucidate biochemical mechanism to appraise its activity. Method: We examined the protective effect of AMC in both in vitro and in vivo models of galactose-induced cataract in rats and compared the effect with captopril. We evaluated the effect of both captopril and AMC on onset and maturation of cataract in galactosemic cataract. Result: AMC reduced the rat lens polyol level, the marker of osmotic stress induced by galactose when compared with galactose treated and captopril treated lens. Glucose-6-phosphate dehydrogenase, succinate dehydrogenase, lactate dehydrogenase activity and reduced glutathione level were decreased in the galactose treated group compared with normal lenses. AMC treatment significantly restored these biochemical levels compared with the galactose treated group. The second, in vivo phase of the study revealed that AMC treatment significantly delayed the onset and maturation of cataract in galactose treated rats compared to captopril treatment. Conclusion: These results support the view that AMC counteracts the effects of galactose in inducing cataract. The anticataract effects of AMC may be related to its intrinsic ability to protect and restore the activities of lens enzymes and the bioavailability of glutathione respectively.

Ditopic Complexation of Selenite Anions or Calcium Cations by Pirenoxine: An Implication for Anti-Cataractogenesis

This study investigated whether and how pirenoxine (PRX) interacts with selenite or calcium ions, as these two ions have been proven respectively a factor leading to the formation of lens cataract. UV, NMR, and isothermal titration calorimetry (ITC) analysis indicated that PRX could bind maximum up to six selenite anions and the binding site preference was concentration dependent with the peripheral binding first followed by the π-π interactions with the aromatic moiety; while for calcium cation interaction the 3-carboxylate and β-ketoimine functional groups were responsible for chelating calcium ions. The results obtained by MP2/6-31+G(d) molecular orbital calculations provided theoretical evidence in support of the π-π interactions between selenite and the PRX aromatic framework, and further analysis of the binding energies with the aromatic moiety indicates that these interactions take place most likely at the benzoquinone (ring I) π-system. The calcium binding preferences with PRX were also determined based on the stabilization energy obtained by B3LYP/6-31+G(d) calculations, showing the binding preferences were site 2 > site 1 > site 3 > ring II, consistent with the experimental data. The in vitro study of the reduction of selenite or calcium ions-induced lens turbidity by PRX with ditopic recognition properties was thus demonstrated. These results may provide a rationale for using PRX as an anti-cataract agent and warrant further biological studies.

Effect of Glutathione With Sea Tangle Extract on Prevention of Selenite-Induced Cataract Formation in Rats

Purpose: To evaluate antioxidative and preventive effects of sea tangle extract on selenite-induced cataract formation. Methods: Eighty SD rat pups were randomized into 8 groups. Group 1 received no injection of reagent (normal); Group 2 to 8 received injection of selenite (15 /Kg, s.c.) was injected. In group 2 (control) and group 3, normal saline (i.p.) and ascorbic acid (i.p.) was injected on days 331. In groups 48, sea tangle extract (i.p.) was injected at a concentration of 12.5, 25, 50, 100, 200 mg/kg, respectively. Development of cataract was assessed and photographed weekly under slit lamp. Rat lenses were analyzed for antioxidant enzymes, glutathione peroxidase (GPx), superoxide dismutase and malondialdehyde. Furthermore, an amino acid analysis of sea tangle extract was performed. Results: Significant differences (p 8 developed nuclear cataract with proportion of 6/10, 3/10, 2/10, 1/10, and 6/10 rats. In sea tangle injected group, levels of GPx were higher than in the ascorbic acid and control groups. In particular, group 7, injected with 100 mg/kg of sea tangle extract, showed significantly high level of enzyme. Results of the amino acid analysis showed sea tangle includes glutamate-glycine-cysteine, major constituents of glutathione (GSH). Conclusions: The glutamate-glycine-cysteine in sea tangle is supposed to increase the level of lens GSH and this may contribute to lowering cataract development. This study strongly supports the activity of sea tangle as an endogenous antioxidant and anticataract agent.

Effect of glutathione with sea tangle extract on prevention of selenite‐induced cataract formation in rat eyes

Abstract Purpose To evaluate antioxidative and preventive effects of sea tangle extract on selenite‐induced cataract formation. Methods Eighty SD rat pups were randomized into 8 groups. Group 1, not injected any reagent (normal); In group 2‐8, selenite(15μmol/Kg, s.c.) was injected on day 11. In group 2 (control) and group 3, normal saline (i.p.) and ascorbic acid (i.p.) was injected on days 3–31; In group 4‐8, sea tangle extract (i.p.) was injected on days 3–31 with concentration of 12.5, 25, 50, 100, 200mg/Kg, respectively. Development of cataract was assessed and photographed weekly under slit lamp photo. After 31st day, rat lenses were analyzed for antioxidant enzymes, glutathione peroxidase (GPx), superoxide dismutase and malondialdehyde. Furthermore, amino acid analysis of sea tangle extract was performed. Results Significant differences (p &lt; 0.05) were seen in cataract development by the 8 groups. No rats developed cataract in group 1; Dense nuclear cataract was developed 8 of 10 and 4 of 10 rats in each group 2 and 3; Group 4‐8 developed nuclear cataract with proportion of 6/10, 3/10, 2/10, 1/10 and 6/10 rats. In sea tangle injected group (group 4‐8), levels of GPx were higher than those in ascorbic acid and control group. Especially, group 7, injected with 100mg/kg of sea tangle extract showed significantly high level of enzyme. Results of amino acid analysis showed sea tangle includes glutamate‐glycine‐cysteine, major constituents of glutathione(GSH). Conclusion The glutamate‐glycine‐cysteine in sea tangle is supposed to increase the level of lens GSH and this may contribute to lowering cataract development. This study strongly supports the activity of sea tangle as an endogenous antioxidant and anticataract agent.

Medical treatment of cataract

The incidence of cataract continues to increase with the ageing of the population. Surgical treatment with phacoemulsification and intraocular lens implantation remains the only proven treatment. This, however, is associated with significant cost and is not readily available especially in the developing countries where the prevalence of cataract is the highest. Medical treatment of cataract is therefore a highly desired alternative. Since the last major review of medical treatment of cataract the search for an anti-cataract agent has advanced on many fronts. Some anti-cataract drugs, such as carnosine, have now reached clinical trials and showed encouraging results that warrant further investigation. The discovery of an effective medical treatment for cataract is likely to make global impact on eye health. The aims of this paper are to review the literature on the drug therapy of cataract and provide updates of the latest development.