curcumin and Cataract

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

Topics: Bibliometrics; Cataract; Curcumin; Humans; Lanosterol; Metformin; Oxysterols; Resveratrol

This review discusses the relationship between oxidative stress and cataract formation, molecular mechanism of curcumin action and potential benefits of treatment with the antioxidant curcumin. The first section deals with curcumin and endogenous antioxidants. The second section focuses on the action of curcumin on lipid peroxidation. Calcium homeostasis and curcumin will be discussed in the third section. The fourth section discusses the role of crystallin proteins that are responsible for maintaining lens transparency and the role of curcumin in regulating crystallin expression. The interaction of curcumin with transcription factors will be dealt in the fifth section. The final section will focus on the effect of curcumin on aldose reductase, which is associated with hyperglycemia and cataract. One of the strongest antioxidants is curcumin which has been shown to be very effective against cataract. This compound is better than other antioxidants in preventing cataract but its limited bioavailability can be addressed by employing nanotechnology.

Topics: Aldehyde Reductase; Antioxidants; Biological Availability; Calcium; Cataract; Crystallins; Curcumin; Humans; Lens, Crystalline; Lipid Peroxidation; Transcription, Genetic

The major causes for cataract formation are free radicals, and these free radicals are neutralized by the presence of endogenous antioxidants in the eye. Using xenobiotics, it has been confirmed that free radicals mediate the formation of cataract. Two cataract model-selenite model and the diabetic cataract model-have been developed to study the pathophysiology of cataract formation due to free radicals and the role of antioxidants during the process of cataractogenesis. This review focuses on natural compounds with antioxidant properties that could actually be applied as an interventional strategy on a large scale and are also relatively inexpensive. A brief overview of plants with antioxidant properties that in addition possess potential anti-cataract properties has been discussed. In addition to plants, three natural compounds (curcumin, vitamin C and vitamin E), on which a lot of data exist showing anti-cataract and antioxidant activities, have also been discussed. These antioxidants can be supplemented in the diet for a better defence against free radicals. Studies on vitamin C and vitamin E have proved that they are capable of preventing lipid peroxidation, thereby preventing the generation of free radicals, but their efficacy as anti-cataract agent is questionable. Unlike vitamins C and E, curcumin is well established as an anti-cataract agent, but the issue of curcumin bioavailability is yet to be addressed. Nanotechnology proves to be a promising area in increasing the curcumin bioavailability, but still a lot more research needs to be done before the use of curcumin as an effective anti-cataract agent for humans.

Topics: Antioxidants; Ascorbic Acid; Cataract; Curcumin; Dietary Supplements; Free Radicals; Humans; Lens, Crystalline; Oxidation-Reduction; Oxidative Stress; Vitamin E

Therapeutic interventions that counter emerging targets in diabetes eye diseases are lacking. We hypothesize that a combination therapy targeting inflammation and hyperglycemia can prevent diabetic eye diseases. Here, we report a multipronged approach to prevent diabetic cataracts and retinopathy by combining orally bioavailable curcumin-laden double-headed (two molecules of gambogic acid conjugated to terminal carboxyl groups of poly(d,l-lactide-

Topics: Animals; Anti-Inflammatory Agents; Cataract; Curcumin; Diabetes Mellitus, Experimental; Hyperglycemia; Insulin; Insulin, Long-Acting; Ion Channels; Mice; Nanoparticles; Retinal Diseases; Rodentia

Cataract is the leading cause of blindness in elderly people worldwide, especially in developing countries. Studies to identify strategies that can prevent or retard cataract formation are urgently required. This study aimed to investigate the potential mechanism of the cytoprotective effects of curcumin in in vivo and in vitro experiments.. Male Wistar rats were randomly divided into three groups: the control group, the model group (administered 20 μmol/kg sodium selenite), and the curcumin group (pretreated with 75 mg/kg body weight curcumin 24 h prior to the administration of sodium selenite). The expression levels of heat shock protein 70 (HSP70), the activities of 8-hydroxy-2-deoxyguanosine (8-OHdG), catalase (CAT), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were assessed by using RT-PCR assay and ELISA. In addition, the cell viability, cell apoptosis, and cell cycle were assessed using a CCK-8 assay and flow cytometry in in vitro studies, followed by RT-PCR analysis to identify the mRNA expression levels of caspase 3, Bcl-2 associated X (Bax), B-cell lymphoma 2 (Bcl-2), cyclooxygenase (Cox-2), c-met, and Slug.. Cataract was successfully established in rats of the model group and the curcumin group through intraperitoneal injection of sodium selenite. The expression levels of HSP70 and the activities of 8-OHdG and MDA in the curcumin group were decreased compared with those in the model group, whereas the activities of CAT, SOD, and GSH-Px were significantly higher than those in the model group (P < 0.05). In the in vitro studies, the cell viability and cell apoptosis significantly increased and decreased, respectively, in the curcumin group compared with the model group. Correspondingly, the mRNA expression of caspase-3, Bax, and Cox-2 was lower in the curcumin group than in the model group (P < 0.05).. This study suggested that curcumin attenuated selenite-induced cataract through the reduction of the intracellular production of reactive oxygen species and the protection of cells from oxidative damage.

Topics: Animals; Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Cataract; Cell Survival; Curcumin; Cyclooxygenase 2; Cytoprotection; Disease Models, Animal; Glutathione Peroxidase; Lens, Crystalline; Male; Malondialdehyde; Oxidative Stress; Rats; Rats, Wistar; Reactive Oxygen Species; Superoxide Dismutase

Curcumin (Cur) exhibits anticataractogenesis activity. This study aimed to compare the activities of Cur with those of its degradation products in a series of in vitro lens protein turbidity assays. The results show that Cur (200 μM) ameliorates selenite-induced crystallin aggregation, and the mean OD value was 0.10 ± 0.02 (p < 0.05), which was significantly different from controls (0.15 ± 0.01) after incubating for 3 days. However, Cur did not significantly inhibit calcium-induced proteolysis after incubating for 3 days. Such results were supported by isothermal titration calorimetry observation that Cur binds with selenite but not with calcium. Presence of Cur and the degradation products examined (ferulic acid, cinnamic acid, vanillin, and vanillic acid) indicates significantly protective activities on lens γ-crystallins after UVC exposure for 3 h. Among the compounds examined, only ferulic acid exhibited a significant inhibitory effect against UVB-induced turbidity with a mean OD of 0.32 ± 0.01 (p < 0.05), which was significantly different from controls (0.49 ± 0.02). The previously reported anticataract effects of Cur may stem not only from Cur but also from its degradation products through various cataractogenesis mechanisms in vitro.

Topics: Animals; Cataract; Crystallins; Curcumin; Humans; In Vitro Techniques; Lens, Crystalline; Molecular Structure; Swine

In this report, the in vitro relative capabilities of curcumin (CCM) and didemethylated curcumin (DCCM) in preventing the selenite-induced crystallin aggregation were investigated by turbidity tests and isothermal titration calorimetry (ITC). DCCM showed better activity than CCM. The conformers of CCM/SeO3(2-) and DCCM/SeO3(2-) complexes were optimized by molecular orbital calculations. Results reveal that the selenite anion surrounded by CCM through the H-bonding between CCM and selenite, which is also observed via IR and NMR studied. For DCCM, the primary driving force is the formation of an acid-base adduct with selenite showing that the phenolic OH group of DCCM was responsible for forming major conformer of DCCM. The formation mechanisms of selenite complexes with CCM or DCCM explain why DCCM has greater activity than CCM in extenuating the toxicity of selenite as to prevent selenite-induced lens protein aggregation.

Topics: Acids; Cataract; Crystallins; Curcumin; Humans; Hydrogen Bonding; Magnetic Resonance Spectroscopy; Protein Aggregates; Selenious Acid

Curcumin, the active principle present in the yellow spice turmeric, has been shown to exhibit various pharmacological actions such as antioxidant, anti-inflammatory, antimicrobial, and anti-carcinogenic activities. Previously we have reported that dietary curcumin delays diabetes-induced cataract in rats. However, low peroral bioavailability is a major limiting factor for the success of clinical utilization of curcumin. In this study, we have administered curcumin encapsulated nanoparticles in streptozotocin (STZ) induced diabetic cataract model. Oral administration of 2 mg/day nanocurcumin was significantly more effective than curcumin in delaying diabetic cataracts in rats. The significant delay in progression of diabetic cataract by nanocurcumin is attributed to its ability to intervene the biochemical pathways of disease progression such as protein insolubilization, polyol pathway, protein glycation, crystallin distribution and oxidative stress. The enhanced performance of nanocurcumin can be attributed probably to its improved oral bioavailability. Together, the results of the present study demonstrate the potential of nanocurcumin in managing diabetic cataract.

Topics: Aldehyde Reductase; Animals; Antioxidants; Biocompatible Materials; Biodegradation, Environmental; Blood Glucose; Body Weight; Cataract; Crystallins; Curcumin; Diabetes Mellitus, Experimental; Disease Models, Animal; Disease Progression; Feeding Behavior; Insulin; Lactic Acid; Lens, Crystalline; Malondialdehyde; Nanoparticles; Oxidative Stress; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Protein Carbonylation; Rats; Sorbitol; Streptozocin; Superoxide Dismutase; Treatment Outcome

In this study, curcumin derivatives salicylidenecurcumin (CD1) and benzalidenecurcumin (CD2)] were prepared, and their biological activity was compared in in vitro selenite-induced cataract model. The antioxidant activity was studied using DPPH radical scavenging assay. Knoevenagel condensates of curcumin exhibited higher DPPH radical scavenging activity compared with curcumin. The anticataractogenic potential of curcumin derivatives was analyzed using lens organ culture method. The activity of antioxidant enzymes and calcium homeostasis was reversed to near normal levels following treatment in organ cultured rat lenses. These results indicated that curcumin and its derivatives--CD1 and CD2--are beneficial against selenite-induced cataract in vitro. Of these, CD1 is having higher bioactive potential compared with curcumin and CD2.

Topics: Animals; Antioxidants; Benzylidene Compounds; Calcium; Calcium-Transporting ATPases; Cataract; Cells, Cultured; Curcumin; Female; Lens, Crystalline; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Superoxide Dismutase

To investigate the expression of αA- and αB-crystallin and heat shock protein 70 (Hsp 70) during curcumin treatment of selenium-induced cataractogenesis in Wistar rat pups.. Group I Wistar rat pups received only saline and served as the control. Group II Wistar rat pups were intraperitoneally injected with selenium (15 µM/kg bodyweight) to induce cataract. Group III Wistar rat pups also underwent selenium-induced cataract but were cotreated with 75 mg/kg body weight of curcumin (single oral dose). Group IV Wistar rat pups with selenium-induced cataract were post-treated with curcumin at the group III dosage 24 h after selenium administration. Group V Wistar rat pups with selenium-induced cataract were pretreated with curcumin at the group III dosage 24 h before selenium administration.. This study found higher levels of αA- and αB-crystallin and Hsp 70 in lenses injected with selenium alone (group II) than in control lenses (group I). Similar results were observed in the group III and IV lenses. In contrast, in group V, the presence of curcumin 24 h before selenium injection decreased the αA- and αB-crystallin and Hsp 70 levels to almost the same as those found in group I lenses.. Curcumin suppressed the expression of selenite-induced αA- and αB-crystallin and Hsp 70, and may therefore suppress cataract formation in rat pups.

Topics: alpha-Crystallin A Chain; alpha-Crystallin B Chain; Animals; Blotting, Western; Body Weight; Cataract; Curcumin; Gene Expression Regulation; HSP70 Heat-Shock Proteins; Immunohistochemistry; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; Selenium; Sodium Selenite

The generation of free radicals has been implicated in the causation of cataract, and compounds that can scavenge free radicals ameliorate the disease process. This study investigated the possible free radical scavenging potential of curcumin at a dose of 75 mg/kg body wt on selenium-induced cataract in rat pups. Intraperitoneal injection of sodium selenite (15 micromol/kg body wt) into 8- to 10-day-old rat pups led to severe oxidative stress in the eye lens as evidenced by increased nitric oxide, superoxide anion, and hydroxyl radical generation and inducible nitric oxide synthase expression that probably led to cataract formation. Selenium exposure also caused an increase in total calcium in the eye lens and significantly inhibited the activity of Ca(2+) ATPase but not Na(+)/K(+) ATPase or Mg(2+) ATPase. On the other hand, pretreatment with curcumin, but not simultaneous or posttreatment, led to a decrease in oxidative stress and also rescued the selenium-mediated increase in lens Ca(2+) and inhibition of Ca(2+) ATPase activity in the eye lens. The results of this study demonstrate that an increase in free radical generation triggered by selenium could cause inactivation of lens Ca(2+) ATPase leading to Ca(2+) accumulation. This enhanced Ca(2+) can cause activation of calpain-mediated proteolysis in the lens, resulting in lens opacification. Curcumin in this study was able to prevent selenium-induced oxidative stress leading to activation of Ca(2+) ATPase and inhibition of lens opacification. Thus, curcumin has the potential to function as an anticataractogenic agent, possibly by preventing free radical-mediated accumulation of Ca(2+) in the eye lens.

Topics: Animals; Body Weight; Calcium; Calcium-Transporting ATPases; Cataract; Curcumin; Free Radicals; Hydroxyl Radical; Lens, Crystalline; Male; Models, Biological; Oxidative Stress; Oxygen; Rats; Rats, Wistar; Selenium

The present study was aimed at investigating the possible antioxidant potential of curcumin at a dose of 75 mg/kg body weight on selenite-induced cataract in experimental rat pups.. Group I: Control rat pups receiving physiological saline; Group II: Selenite-induced group (15 microM/kg body wt); Group III: Selenite-induced group co-treated with curcumin (single dose of curcumin orally 75 mg/kg body wt); Group IV: Selenite-induced animals post-treated (after 24 hrs) with curcumin at a dose mentioned for group III; Group V: Rat pups were pretreated with curcumin (dose as mentioned in Group III), 24 hrs before the administration of selenite. Encapsulated lenses liver, kidney, and serum were analyzed for antioxidant enzymes and malondialdehyde, a marker of lipid peroxidation.. Intraperitoneal injection of sodium selenite (15 microM/kg body wt) to 8-10-day-old rat pups led to severe oxidative stress in eye lens as evidenced by enhanced LPO levels that led to cataract formation. Sodium selenite also led to decrease in activities of SOD, GST, GPx, CAT with simultaneous decrease in the levels of GSH, vitamin C, and vitamin E. Treatment with curcumin (75 mg/kg body wt) led to a significant decrease in the levels of LPO, enzymic antioxidants, and nonenzymic antioxidants, which were similar to that of control.. Curcumin suppressed selenite-induced oxidative stress and cataract formation in rat pups. The presence of oxidative stress in selenite cataract development and its prevention by curcumin support the possibility that the natural consumption of curcumin in food can help prevent the onset of senile cataract.

Topics: Animals; Animals, Newborn; Antioxidants; Ascorbic Acid; Cataract; Curcumin; Disease Models, Animal; Glutathione; Injections, Intraperitoneal; Lens, Crystalline; Lipid Peroxidation; Male; Oxidative Stress; Oxidoreductases; Rats; Rats, Wistar; Sodium Selenite; Vitamin E

The aim of this study was to investigate whether curcumin and aminoguanidine (AG) prevent selenium-induced cataractogenesis in vitro. On postpartum day 8, transparent isolated lens were incubated in 24 well plates containing Dulbecco's Modified Eagle Medium (DMEM). Isolated lens of group I were incubated with DMEM medium alone. Group II: lenses incubated in DMEM containing 100microM sodium selenite; group III: lenses incubated in DMEM containing 100microM sodium selenite and 100microM curcumin; group IV: lenses incubated in DMEM containing 100microM sodium selenite and 200microM curcumin; group V: lenses incubated in DMEM containing 100microM sodium selenite and 100microM AG; group V: lenses incubated in DMEM containing 100microM sodium selenite and 200microM AG. On day 12, cataract development was graded using an inverted microscope and the lenses were analyzed for enzymic as well as non-enzymic antioxidants, lipid peroxidation (LPO), nitric oxide (NO), superoxide anion (O(2)(-)) and hydroxyl radical generation (OH) and inducible nitric oxide synthase (iNOS) activity by Western blotting and RT-PCR. All control lenses in group I were clear (0). In groups II and III, all isolated lenses developed cataract with variation in levels (+++ or ++), whereas isolated lenses from groups IV, V and VI were clear (0). In agreement to this, a decrease in antioxidants and increased free radical generation and also iNOS expression were observed in selenium exposed lenses when compared to other groups. AG (100microM) was found to be more effective in anti-cataractogenic effect than curcumin (200microM). Curcumin and AG suppressed selenium-induced oxidative stress and cataract formation in isolated lens from Wistar rat pups, possibly by inhibiting depletion of enzymic as well as non-enzymic antioxidants, and preventing uncontrolled generation of free radicals and also by inhibiting iNOS expression. Our results implicate a major role for curcumin and AG in preventing cataractogenesis in selenite-exposed lenses, wherein AG was found to be more potent.

Topics: Animals; Base Sequence; Catalase; Cataract; Curcumin; DNA Primers; Glutathione; Glutathione Peroxidase; Glutathione Transferase; Guanidines; Hydroxyl Radical; In Vitro Techniques; Lens, Crystalline; Nitric Oxide Synthase Type II; Oxidative Stress; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction; Selenium; Superoxide Dismutase

Natural dietary ingredients are known for their antioxidant activity. Of such, curcumin, the active principle of turmeric, at 0.01% in the diet proved as pro-oxidative in galactose-induced cataract in vivo. The purpose of this study was to investigate the effect of vitamin E (VE), a well-known antioxidant, in combination with curcumin on the onset and maturation of galactose induced cataract. Periodic slit-lamp microscope examination indicated that in combination with vitamin-E, 0.01% curcumin (G-IV) delayed the onset and maturation of galactose-induced cataract. Biochemical analyses revealed that combined treatment of 0.01% curcumin and vitamin-E diet exhibited an efficient antioxidant effect, as it inhibited lipid peroxidation and contributed to a distinct rise in reduced glutathione content. The results indicate that natural dietary ingredients are effective in combination rather than the individual administration as they are complementing each other in reducing the risk of galactose induced cataract.

Topics: Animals; Antioxidants; Cataract; Curcumin; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Galactose; Glutathione; Glutathione Reductase; Lens, Crystalline; Lipid Peroxides; Male; Oxidative Stress; Rats; Rats, Wistar; Superoxide Dismutase; Vitamin E

To investigate the effects of natural drug curcumin (Cur) on apoptosis of lens epithelial cell (LEC) in vitro and its mechanism.. The bovine LEC were cultured with Cur, the ultrastructure changes were observed under transmission electron microscope (TEM), the DNA content and mitochondrial transmembrane potential (DeltaPsim) changes were studied by flow cytometry (FCM).. The typical morphological changes of LEC apoptosis in Cur group detected by TEM included chromatin condensation and aggregation at the periphery of the nucleons and nuclear fragmentation. The DNA content of LEC in Cur group decreased time-dependently. The DNA content was significantly lower than that of the control group (P < 0.01). The DeltaPsim of LEC in Cur group was decreased, appeared in early stage (8 hours) and reached the maximum after 72 hours. The difference of DeltaPsim of LEC between Cur group and the control group was significant (P < 0.01).. Cur can remarkably induce apoptosis of LEC in vitro. Cur induced LEC apoptosis is caused by decrease of DNA content in LEC nucleus. Collapse of DeltaPsim in cytoplasm induced by Cur results in the irreversible apoptosis process of LEC. This is the early event of LEC apoptosis. LEC apoptosis induced by Cur may pass through two pathways: nuclear pathway and cytoplasmic pathway. The apoptosis of LEC induced by Cur may be the cellular and molecular mechanisms of reducing lens posterior capsular opacification by Cur. Cur may become an effective and low toxic medication for the prevention and treatment of after-cataract.

Topics: Animals; Apoptosis; Cataract; Cattle; Cells, Cultured; Curcumin; DNA Fragmentation; Epithelial Cells; Flow Cytometry; Lens Capsule, Crystalline; Lens, Crystalline; Membrane Potentials; Mitochondria

The purpose of this study was to investigate the effect of curcumin and its source, turmeric, on streptozotocin-induced diabetic cataract in rats.. Wistar-NIN rats were selected and diabetes was induced by streptozotocin (35 mg/kg body weight, intraperitoneally) and divided into four groups (group II-V). The control (group I) rats received only vehicle. Group I and II animals received an unsupplemented AIN-93 diet, and those in groups III, IV, and V received 0.002% and 0.01% curcumin and 0.5% turmeric, respectively, in an AIN-93 diet for a period of 8 weeks. Cataract progression due to hyperglycemia was monitored by slit lamp biomicroscope and classified into four stages. At the end of 8 weeks, the animals were killed and the biochemical pathways involved in the pathogenesis of cataract such as oxidative stress, polyol pathway, alterations in protein content and crystallin profile in the lens were investigated, to understand the possible mechanism of action of curcumin and turmeric. Blood glucose and insulin levels were also determined.. Although, both curcumin and turmeric did not prevent streptozotocin-induced hyperglycemia, as assessed by blood glucose and insulin levels, slit lamp microscope observations indicated that these supplements delayed the progression and maturation of cataract. The present studies suggest that curcumin and turmeric treatment appear to have countered the hyperglycemia-induced oxidative stress, because there was a reversal of changes with respect to lipid peroxidation, reduced glutathione, protein carbonyl content and activities of antioxidant enzymes in a significant manner. Also, treatment with turmeric or curcumin appears to have minimized osmotic stress, as assessed by polyol pathway enzymes. Most important, aggregation and insolubilization of lens proteins due to hyperglycemia was prevented by turmeric and curcumin. Turmeric was more effective than its corresponding levels of curcumin.. The results indicate that turmeric and curcumin are effective against the development of diabetic cataract in rats. Further, these results imply that ingredients in the study's dietary sources, such as turmeric, may be explored for anticataractogenic agents that prevent or delay the development of cataract.

Topics: Animals; Blood Glucose; Body Weight; Cataract; Chromatography, Gel; Crystallins; Curcuma; Curcumin; Diabetes Mellitus, Experimental; Diet; Disease Progression; Eating; Electrophoresis, Polyacrylamide Gel; Glutathione; Hyperglycemia; Insulin; Lipid Peroxidation; Male; Oxidative Stress; Oxidoreductases; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances

A decline in the chaperone-like activity of eye lens alpha-crystallin in diabetic conditions has been reported. In this study, we investigated whether curcumin, a dietary antioxidant, can manipulate the chaperone-like activity of alpha-crystallin in diabetic rat lens.. A group of rats received ip injection of streptozotocin (STZ; 35 mg/kg body weight in buffer) to induce hyperglycemia, while another group of rats received only buffer as vehicle and served as control. STZ-treated rats were assigned to 3 groups and fed either no curcumin or 0.002% or 0.01% curcumin, respectively. Cataract progression due to hyperglycemia was monitored with a slit lamp biomicroscope. At the end of 8 weeks animals were sacrificed and lenses were collected. alphaH- and alphaL-crystallins from a set of pooled lenses in each group were isolated by gel filtration. Chaperone activity, hydrophobicity, and secondary and tertiary structure of alphaH- and alphaL-crystallins were assessed by light scattering/spectroscopic methods.. A decrease in chaperone-like activity of alphaH- and alphaL-crystallins was observed in STZ-treated diabetic rats. The declined chaperone-like activity due to hyperglycemia was associated with reduced hydrophobicity and altered secondary and tertiary structure of alphaH- and alphaL-crystallins. Interestingly, alphaH- and alphaL-crystallins isolated from curcumin fed diabetic rat lenses had shown improved chaperone-like activity as compared to alphaH- and alphaL-crystallins from untreated diabetic rat lens. Feeding of curcumin prevented the alterations in hydrophobicity and structural changes due to STZ-induced hyperglycemia. Modulation of functional and structural properties by curcumin was found to be greater with the alphaL-crystallin than alphaH-crystallin. Loss of chaperone activity of alpha-crystallin, particularly alphaL-crystallin, in diabetic rat lens could be attributed at least partly to increased oxidative stress. Being an antioxidant, curcumin feeding has prevented the loss of alpha-crystallin chaperone activity and delayed the progression and maturation of diabetic cataract.. We demonstrate that curcumin, at the levels close to dietary consumption, prevented the loss of chaperone-like activity of alpha-crystallin vis-a-vis cataractogenesis due to diabetes in rat lens.

Topics: alpha-Crystallins; Animals; Antioxidants; Blood Glucose; Body Weight; Cataract; Chromatography, Gel; Circular Dichroism; Curcumin; Diabetes Mellitus, Experimental; Diet; Hyperglycemia; Lens, Crystalline; Male; Molecular Chaperones; Rats; Spectrometry, Fluorescence

Wistar rat pups treated with curcumin, a natural constituent of Curcuma longa before being administered with selenium showed no opacities in the lens. The lipid peroxidation, xanthine oxidase enzyme levels in the lenses of curcumin and selenium co-treated animals were significantly less when compared to selenium treated animals. The superoxidase dismutase and catalase enzyme activities of curcumin and selenium co-treated animal lenses showed an enhancement. Curcumin co-treatment seems to prevent oxidative damage and found to delay the development of cataract.

Topics: Animals; Antioxidants; Catalase; Cataract; Curcumin; Enzyme Inhibitors; Lipid Peroxidation; Rats; Rats, Wistar; Selenium; Time Factors; Xanthine Oxidase

Curcumin, the active principle of turmeric, has been shown to have both antioxidant and hypoglycemic activity in vitro and in vivo. The purpose of this study was to investigate the effect of curcumin on the onset and maturation of galactose induced cataract.. Sprague-Dawley rats (21 days old) were divided into 5 groups. The control group (A) received an AIN-93 diet, the galactose group (B) received 30% galactose in the diet, the test groups (C and D) received the B group diet plus 0.002% and 0.01% curcumin respectively, and group (E) received the control diet plus 0.01% curcumin, all for a period of 4 weeks. Cataract progression due to galactose feeding was monitored by slit lamp microscope and classified into 4 stages. At the end of the experiment biochemical parameters such as lipid peroxidation, aldose reductase (AR), sorbitol dehydrogenase (SDH), reduced glutathione, protein content, and protein carbonyls were measured in the lens. Advanced glycated end products (AGE) and protein oxidation were measured by AGE and tryptophon fluorescence respectively. Crystallin profile was analyzed by size exclusion chromatography (HPLC).. Slit lamp microscope observations indicated that curcumin at 0.002% (group C) delayed the onset and maturation of cataract. In contrast even though there was a slight delay in the onset of cataract at the 0.01% level (group D), maturation of cataract was faster when compared to group B. Biochemical analysis showed that curcumin at the 0.002% level appeared to exert antioxidant and antiglycating effects, as it inhibited lipid peroxidation, AGE-fluorescence, and protein aggregation. Though the reasons for faster onset and maturation of cataract in group D rats was not clear, the data suggested that under hyperglycemic conditions higher levels of curcumin (0.01%) in the diet may increase oxidative stress, AGE formation, and protein aggregation. However, feeding of curcumin to normal rats up to a 0.01% level did not result in any changes in lens morphology or biochemical parameters.. These results suggest that curcumin is effective against galactose-induced cataract only at very low amounts (0.002%) in the diet. On the other hand at and above a 0.01% level curcumin seems to not be beneficial under hyperglycemic conditions, at least with the model of galactose-cataract.

Topics: Aldehyde Reductase; Animals; Antioxidants; Body Weight; Cataract; Chromatography, Gel; Chromatography, High Pressure Liquid; Crystallins; Curcumin; Disease Models, Animal; Eating; Galactose; Glutathione; Glycation End Products, Advanced; L-Iditol 2-Dehydrogenase; Lens, Crystalline; Lipid Peroxidation; Male; Oxidative Stress; Rats; Rats, Sprague-Dawley

Administration of naphthalene is known to cause cataract formation in rats and rabbits and naphthalene-initiated cataract is frequently used as a model for studies on senile cataract in humans. Oxidative stress has been implicated in the mechanism of naphthalene-induced cataract. Curcumin, a constituent of turmeric, a spice used in Indian curry dishes, is an effective antioxidant and is known to induce the enzymes of glutathione-linked detoxification pathways in rats. During the present studies, we have examined whether low levels of dietary curcumin could prevent naphthalene-induced opacification of rat lens. The presence of apoptotic cells in lens epithelial cells was also examined by catalytically incorporating labeled nucleotide to DNA with either Klenow fragment of DNA polymerase or by terminal deoxynucleotidyl transferase (TdT), which forms polymeric tail using the principle of TUNEL assay. The results of these studies demonstrated that the rats treated with naphthalene and kept on a diet supplemented with only 0.005% (w/w) curcumin had significantly less opacification of lenses as compared to that observed in rats treated only with naphthalene. Our studies also demonstrate, for the first time, that naphthalene-initiated cataract in lens is accompanied and perhaps preceded by apoptosis of lens epithelial cells and that curcumin attenuates this apoptotic effect of naphthalene.

Topics: Administration, Oral; Animals; Apoptosis; Cataract; Curcumin; Dietary Supplements; Epithelial Cells; Fluorescein; Lens, Crystalline; Male; Naphthalenes; Rats; Rats, Sprague-Dawley

Age-related cataractogenesis is a significant health problem worldwide. Oxidative stress has been suggested to be a common underlying mechanism of cataractogenesis, and augmentation of the antioxidant defenses of the ocular lens has been shown to prevent or delay cataractogenesis. The present studies were designed to test the efficacy of curcumin, an antioxidant present in the commonly used spice turmeric, in preventing cataractogenesis in an in vitro rat model. Rats were maintained on an AIN-76 diet (ICN Pharmaceuticals Inc, Cleveland) for 2 wk, after which they were given a daily dose of corn oil alone or 75 mg curcumin/kg in corn oil for 14 d. Their lenses were removed and cultured for 72 h in vitro in the presence or absence of 100 mumol 4-hydroxy-2-nonenal (4-HNE)/L, a highly electrophilic product of lipid peroxidation. The results of these studies showed that 4-HNE caused opacifications of cultured lenses as indicated by the measurements of transmitted light intensity using digital image analysis. However, the lenses from curcumin-treated rats were much more resistant to 4-HNE-induced opacification than were lenses from control animals. Curcumin treatment caused a significant induction of the glutathione S-transferase (GST) isozyme rGST8-8 in rat lens epithelium. Because rGST8-8 utilizes 4-HNE as a preferred substrate, we suggest that the protective effect of curcumin may be mediated through the induction of this GST isozyme. These studies suggest that curcumin may be an effective protective agent against cataractogenesis induced by lipid peroxidation.

Topics: Aldehydes; Animals; Antioxidants; Cataract; Curcumin; Disease Models, Animal; Epithelium; Glutathione Transferase; Immunohistochemistry; Lens, Crystalline; Lipid Peroxidation; Organ Culture Techniques; Oxidative Stress; Random Allocation; Rats