curcumin and Diabetic-Retinopathy

Diabetic retinopathy (DR) is a form of retinal microangiopathy that occurs as a result of long-term Diabetes mellitus (DM). Patients with Diabetes mellitus typically suffer from DR as a progression of the disease that may be due to initiation and dysregulation of pathways like the polyol, hexosamine, the AGE/RAGE, and the PKC pathway, which all have negative impacts on eye health and vision. In this review, various databases, including PubMed, Google Scholar, Web of Science, and Science Direct, were scoured for data relevant to the aforementioned title. The three most common therapies for DR today are retinal photocoagulation, anti-vascular endothelial growth factor (VEGF) therapy, and vitrectomy, however, there are a number of drawbacks and limits to these methods. So, it is of critical importance and profound interest to discover treatments that may successfully address the pathogenesis of DR. Curcumin and β-glucogallin are the two potent compounds of natural origin that are already being used in various nutraceutical formulations for several ailments. They have been shown potent antiapoptotic, anti-inflammatory, antioxidant, anticancer, and pro-vascular function benefits in animal experiments. Their parent plant species have been used for generations by practitioners of traditional herbal medicine for the treatment and prevention of various eye ailments. In this review, we will discuss about pathophysiology of Diabetic retinopathy and the therapeutic potentials of curcumin and β-glucogallin one of the principal compounds from Curcuma longa and Emblica officinalis in Diabetic retinopathy.

Topics: Animals; Curcumin; Diabetes Mellitus; Diabetic Retinopathy; Humans; Hydrolyzable Tannins; Retina

To review the role of curcumin in retinal diseases, COVID era, modification of the molecule to improve bioavailability and its future scope.. PubMed and MEDLINE searches were pertaining to curcumin, properties of curcumin, curcumin in retinal diseases, curcumin in diabetic retinopathy, curcumin in age-related macular degeneration, curcumin in retinal and choroidal diseases, curcumin in retinitis pigmentosa, curcumin in retinal ischemia reperfusion injury, curcumin in proliferative vitreoretinopathy and curcumin in current COVID era.. In experimental models, curcumin showed its pleiotropic effects in retinal diseases like diabetic retinopathy by increasing anti-oxidant enzymes, upregulating HO-1, nrf2 and reducing or inhibiting inflammatory mediators, growth factors and by inhibiting proliferation and migration of retinal endothelial cells in a dose-dependent manner in HRPC, HREC and ARPE-19 cells. In age-related macular degeneration, curcumin acts by reducing ROS and inhibiting apoptosis inducing proteins and cellular inflammatory genes and upregulating HO-1, thioredoxin and NQO1. In retinitis pigmentosa, curcumin has been shown to delay structural defects of P23H gene in P23H-rhodopsin transgenic rats. In proliferative vitreoretinopathy, curcumin inhibited the action of EGF in a dose- and time-dependent manner. In retinal ischemia reperfusion injury, curcumin downregulates IL-17, IL-23, NF. Curcumin is an easily available spice used traditionally in Indian cooking. The benefits of curcumin are manifold, and large randomized controlled trials are required to study its effects not only in treating retinal diseases in humans but in their prevention too.

Topics: Animals; COVID-19; Curcumin; Diabetic Retinopathy; Endothelial Cells; Humans; Macular Degeneration; Rats; Reperfusion Injury; Retinal Diseases; Retinal Neoplasms; Retinitis Pigmentosa; Vitreoretinopathy, Proliferative

Diabetic retinopathy (DR) is a type of retinal microangiopathy caused by diabetes mellitus. It has become the leading cause of blindness among working individuals worldwide. DR is becoming increasingly common among younger diabetic patients and there is a need for lifelong treatment. The pathogenic mechanisms of DR are influenced by a number of factors, such as hyperglycemia, hyperlipidemia, inflammatory response and oxidative stress, among others. Currently, the treatment methods for DR mainly include retinal photocoagulation, vitrectomy, or anti‑vascular endothelial growth factor (VEGF) therapy. However, these methods have some disadvantages and limitations. Therefore, it is a matter of great interest and urgency to discover drugs that can target the pathogenesis of DR. Since ancient times, traditional Chinese medicine practitioners have accumulated extensive experiences in the use of Chinese herbal medicine for the prevention and treatment of diseases. In the theory of traditional Chinese medicine, curcumin has the effects of promoting blood circulation and relieving pain. A number of studies have also demonstrated that curcumin has multiple biological activities, including exerting anti‑apoptotic, anti‑inflammatory, antioxidant and antitumor properties. In recent years, studies have also confirmed that curcumin can prevent a variety of diabetic complications, including diabetic nephropathy (DN). However, the preventive and curative effects of curcumin on DR and its mechanisms of action have not yet been fully elucidated. The present review aimed to explore the therapeutic potential of curcumin in diabetes mellitus and DR.

Topics: Animals; Anti-Inflammatory Agents; Curcumin; Diabetic Retinopathy; Humans; Medicine, Chinese Traditional

Curcumin, the major extraction of turmeric, has been widely used in many countries for centuries both as a spice and as a medicine. In the last decade, researchers have found the beneficial effects of curcumin on multiple disorders are due to its antioxidative, anti-inflammatory, and antiproliferative properties, as well as its novel function as an inhibitor of histone aectyltransferases. In this review, we summarize the recent progress made on studying the beneficial effects of curcumin on multiple retinal diseases, including diabetic retinopathy, glaucoma, and age-related macular degeneration. Recent clinical trials on the effectiveness of phosphatidylcholine formulated curcumin in treating eye diseases have also shown promising results, making curcumin a potent therapeutic drug candidate for inflammatory and degenerative retinal and eye diseases.

Topics: Animals; Anti-Inflammatory Agents; Clinical Trials as Topic; Curcuma; Curcumin; Diabetic Retinopathy; Disease Models, Animal; Glaucoma; Humans; Inflammation; Macular Degeneration; Retinal Diseases; Retinitis Pigmentosa; Retinoblastoma; Vitreoretinopathy, Proliferative

In the present study, the improvement of diabetic microangiopathy and retinopathy was evaluated in 38 diabetic patients treated with a novel curcumin phospholipids delivery form (Meriva®).. Diabetes was diagnosed at least 5 years before inclusion and all patients had signs of retinal oedema and of peripheral microangiopathy. Meriva® was administered at the dosage of 2 tablets/day (each tablet containing 500 mg Meriva® corresponding to 100 mg curcumin) for a period of at least 4 weeks in addition to the standard management plan, while a comparable group of subjects (n = 39) followed the standard management plan alone.. All subjects (treatment and controls) completed the follow-up period, there were no dropouts and Meriva® showed an optimal tolerability. At 4 weeks, microcirculatory and clinical evaluations indicated an improvement of microangiopathy. In terms of peripheral microangiopathy, in the Meriva® group, there was a significant improvement in the venoarteriolar response (p<0.05) and a decrease in the score of peripheral oedema (p<0.05), a sign typically associated with the failure of the venoarteriolar response. At the retinal level, high-resolution, duplex scanning, used to measure retinal flow, showed improvements in the Meriva® treated patients. The evaluation of retinal oedema (Steigerwalt's scale) showed an improvement associated with improved visual acuity (Snellen scale). There were no clinical or microcirculatory effects in controls.. These preliminary observations, indicate the value of curcumin, when administered in a bioavailable form as with Meriva®, in the management of diabetic microangiopathy and retinopathy.

Topics: Curcumin; Diabetic Angiopathies; Diabetic Retinopathy; Drug Delivery Systems; Edema; Female; Humans; Laser-Doppler Flowmetry; Lecithins; Male; Microcirculation; Middle Aged; Pilot Projects; Regional Blood Flow; Retina

In traditional Chinese medicine, the causes of diabetic retinopathy (DR) are blood stasis and heat. Curcuma wenyujin Y. H. Chen & C. Ling and its extracts have the effects of promoting blood circulation to remove blood stasis, clearing the heart, and cooling the blood, and have been used in the treatment of DR. Elema-1,3,7 (11),8-tetraen-8,12-lactam (Ele), an N-containing sesquiterpene isolated from this plant. However, the anti-inflammatory and anti-angiogenic effects of Ele and its therapeutic potential in DR are still unknown.. To evaluate the anti-inflammatory and anti-angiogenic effects of Ele and its therapeutic potential in DR.. In vitro, anti-inflammatory and anti-angiogenic effects were assessed using TNF-α or VEGF-stimulated HUVECs. Protein expression was analyzed using Western blotting. ICAM-1 and TNF-α mRNA expressions were analyzed using real-time quantitative RT-PCR. The therapeutic potential in DR was assessed using both animal models of STZ-induced diabetes and oxygen-induced retinopathy. The retinal vascular permeability was measured using Evans blue, and the quantitation of retinal leukostasis using FITC-coupled Con A. The retinal neovascular tufts were analyzed using fluorescein angiography and counting pre-retinal vascular lumens.. Ele inhibited NF-κB pathway, and ICAM-1, TNF-α mRNA expression in TNF-α- stimulated HUVECs. It also inhibits the multistep process of angiogenesis by inhibiting the phosphorylation of VEGFR2 and its downstream signaling kinases Src, Erk1/2, Akt, and mTOR in VEGF-stimulated HUVECs. Intravitreal injection of Ele can significantly reduce retinal microvascular leakage, leukostasis, and expression of ICAM-1, TNF-α in diabetic rats and inhibits oxygen-induced retinal neovascularization and VEGFR2 phosphorylation in OIR mice.. Ele has anti-inflammatory and anti-angiogenic effects through inhibiting NF-κB and VEGFR2 signaling pathways, and it may be a potential drug candidate for DR.

Topics: Animals; Anti-Inflammatory Agents; Curcuma; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Intercellular Adhesion Molecule-1; Leukostasis; Mice; NF-kappa B; Oxygen; Rats; RNA, Messenger; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A

Diabetic retinopathy (DR) is one of the most common complications of diabetes and has become a major global cause of blindness. Curcumin, an extract of Curcuma longa (turmeric), is effective in preventing and treating diabetes. Recent studies have shown that curcumin can delay DR development. However, there has been no systematic review of its treatment of DR. This study will conduct a systematic review and meta-analysis of currently published randomized controlled trials (RCT) of curcumin for treating DR patients to evaluate its efficacy and safety.. We will search the relevant studies of curcumin in the treatment of DR in PubMed, Medline, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP, and Wanfang databases from their respective inception dates to May 2022. A meta-analysis of the data extracted from qualified RCTs will be conducted, including the progression of DR, visual acuity, visual field, macular edema, quality of life, and adverse events. The meta-analysis will be performed using Review Manager 5.4.1 software, and the results will be based on either random-effects or fixed-effects models, depending on the heterogeneity. The Grading of Recommendations, Development, and Evaluation (GRADE) system will be used to evaluate the reliability and quality of evidence.. The results of this study will provide sound and high-quality evidence for the efficacy and safety of curcumin in the treatment of DR.. This study will be the first meta-analysis to comprehensively assess the efficacy and safety of curcumin in the treatment of DR and will provide helpful evidence for the clinical management of this disease.. INPLASY202250002.

Topics: Curcumin; Diabetes Mellitus; Diabetic Retinopathy; Drugs, Chinese Herbal; Humans; Meta-Analysis as Topic; Randomized Controlled Trials as Topic; Systematic Reviews as Topic

Background: To investigate the effects of a fixed combination of Curcumin (200 mg), Artemisia (80 mg), Bromelain (80 mg), and Black pepper (2 mg) on vascular parameters in mild to moderate diabetic macular edema (DME). Design: Prospective, case-control study. Methods: Fifty-six patients affected by diabetes mellitus type II were enrolled in the study. Twenty-eight patients with DME received 2 tablets/day, before meals of a dietary complementary supplement containing in fixed combination Curcumin (200 mg), Artemisia (80 mg), Bromelain (80 mg), and Black pepper (2 mg) (Intravit®, OFFHEALTH Spa, Firenze, Italy) for 6 months. Twenty-eight age-matched subjects affected by diabetes mellitus type II were given placebo and served as control group. Patients underwent best correct visual acuity (BCVA), swept optical coherence tomography (OCT), and OCT-Angiography (OCTA). OCTA images of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were obtained for each eye. By the end of the follow-up patients were defined responder to the therapy when a decrease of more than 30 μm was registered in central retinal thickness (CRT) measurement, while a poor responder was determined by the absence of reduction or an increase in central retinal thickness at 6 months. We assessed the foveal avascular zone (FAZ) area, vessel density and quantified the number of microaneurysms in each layer. Results: A significant improvement of BCVA and CRT reduction was recorded at 6 months follow-up in the dietary complementary supplementation group compared to control (respectively p = 0.028 and p = 0.0003). VD of the total capillary plexus, microaneurysms count, glycaemia and HbA1c did not vary over the follow-up period between groups. Within the Intravit® group, poor responders tended to show a larger FAZ area, more microaneurysms, and a lower VD in the DCP compared to the good responders group (p < 0.0001). Conclusions: A fixed combination of Curcumin, Artemisia, Bromelain, and Black pepper oral administration may have a positive impact on central retinal thickness, visual acuity, and VD of the DCP in compensated type 2 diabetic patients with mild DME.

Topics: Administration, Oral; Artemisia; Bromelains; Case-Control Studies; Curcumin; Diabetes Mellitus; Diabetic Retinopathy; Fluorescein Angiography; Humans; Macular Edema; Microaneurysm; Piper nigrum; Prospective Studies; Retinal Vessels; Retrospective Studies; Tomography, Optical Coherence

Diabetic retinopathy (DR) is a retinal disease caused by metabolic disorders of glucose tolerance that can lead to irreversible blindness if not adequately treated. Retinal pigment epithelial cell (RPEC) dysfunction contributes to the pathogenesis of DR. In the present study the anti‑inflammatory effect of curcumin (CUR) was investigated in RPECs damaged by high glucose levels. RPEC treated with 30 mmol/l glucose was regarded as high glucose group, and cells treated with 24.4 mmol/l mannitol was set as equivalent osmolarity group. Cell Counting Kit‑8 assay was used to measure RPEC viability, the expression of phosphorylated (p)‑AKT and p‑mammalian target of rapamycin (mTOR) were assessed by western blot, and secretion of tumor necrosis factor (TNF)‑α, interleukin (IL)‑6 and IL‑1β in the culture medium was measured by ELISA. Intracellular reactive oxygen species (ROS) levels were measured by laser scanning confocal microscope. The present data indicated that, compared with mannitol treatment, high glucose treatment reduced RPEC viability, increased TNF‑α, IL‑6 and IL‑1β secretion, increased ROS formation and promoted phosphorylation of AKT and mTOR. The antioxidant N‑acetylcysteine, the phosphoinositide 3‑kinase (PI3K)/AKT inhibitor LY294002 and the mTOR inhibitor rapamycin ameliorated the effects of high glucose. In addition, pretreatment with 10 µmol/l CUR reduced secretion levels of TNF‑α, IL‑6 and IL‑1β, ROS formation and phosphorylation of AKT and mTOR. In conclusion, CUR inhibited high glucose‑induced inflammatory injury in RPECs by interfering with the ROS/PI3K/AKT/mTOR signaling pathway. The present study may reveal the molecular mechanism of CUR inhibition effects to high glucose‑induced inflammatory injury in RPEC.

Topics: Acetylcysteine; Anti-Inflammatory Agents; Antioxidants; Cell Line; Chromones; Curcumin; Diabetic Retinopathy; Drug Synergism; Epithelial Cells; Gene Expression Regulation; Glucose; Humans; Interleukin-1beta; Interleukin-6; Models, Biological; Morpholines; Oxidative Stress; Phosphatidylinositol 3-Kinase; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Retinal Pigment Epithelium; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Tumor Necrosis Factor-alpha

To investigate the potential protective effects of curcumin on the retina in diabetic rats.. An experimental diabetic rat model was induced by a low dose of streptozotocin combined with a high-energy diet. Rats which had blood glucose levels ≥11.6 mmol/L were used as diabetic rats. The diabetic rats were randomly divided into 3 groups: diabetic rats with no treatment (DM), diabetic rats treated with 100 mg/kg curcumin (DM + Cur 100 mg/kg), and diabetic rats treated with 200 mg/kg curcumin (DM + Cur 200 mg/kg). Curcumin was orally administered daily for 16 weeks. After 16 weeks of administration, the rats were euthanized, and eyes were dissected. Retinal histology was examined, and the thickness of the retina was measured. Ultrastructural changes of retinal ganglion cells, inner layer cells, retinal capillary, and membranous disks were observed by electron microscopy. Malondialdehyde, superoxide dismutase, and total antioxidant capacity were measured by ELISA. Expression levels of vascular endothelial growth factor (VEGF) in retina tissues were examined by immunohistochemical staining and ELISA. Expression levels of Bax and Bcl-2 in retina tissues were determined by immunohistochemical staining and Western blotting.. Curcumin reduced the blood glucose levels of diabetic rats and decreased diabetes-induced body weight loss. Curcumin prevented attenuation of the retina in diabetic rats and ameliorated diabetes-induced ultrastructure changes of the retina, including thinning of the retina, apoptosis of the retinal ganglion cells and inner nuclear layer cells, thickening of retinal capillary basement membrane and disturbance of photoreceptor cell membranous disks. We also found that curcumin has a strong antioxidative ability in the retina of diabetic rats. It was observed that curcumin attenuated the expression of VEGF in the retina of diabetic rats. We also discovered that curcumin had an antiapoptotic effect by upregulating the expression of Bcl-2 and downregulating the expression of Bax in the retina of diabetic rats.. Taken together, these results suggest that curcumin may have great therapeutic potential in the treatment of diabetic retinopathy which could be attributed to the hypoglycemic, antioxidant, VEGF-downregulating and neuroprotection properties of curcumin.

Topics: Administration, Oral; Animals; Anti-Inflammatory Agents, Non-Steroidal; Biomarkers; Blotting, Western; Curcumin; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Male; Rats; Rats, Sprague-Dawley; Retina; Retinal Ganglion Cells

Hyperglycaemia-induced oxidative stress appears to be involved in the aetiology of diabetic retinopathy (DR), a major public health issue, via altering DNA methylation process. We investigated the effect of hyperglycaemia on retinal DNA methyltransferase (DNMT) expression in diabetic mice, using Gene Expression Omnibus datasets. We also evaluated the effect of curcumin both on high glucose-induced reactive oxygen species (ROS) production and altered DNMT functions, in a cellular model of DR. We observed that three months of hyperglycaemia, in insulin-deficient Ins2

Topics: Animals; Cell Line; Cell Survival; Curcumin; Diabetes Mellitus, Experimental; Diabetic Retinopathy; DNA-Cytosine Methylases; Humans; Oxidative Stress; Reactive Oxygen Species

Retinal inflammation in a hyperglycemic condition is believed to play a crucial role in the development of diabetic retinopathy, and targeting inflammatory mediators is a promising strategy for the control of diabetic retinopathy. Curcumolide, a novel sesquiterpenoid with a unique 5/6/5 tricyclic skeleton, was isolated from Curcuma wenyujin. In this study, we demonstrate that treatment with curcumolide alleviated retinal inflammatory activities both in vitro and in vivo in a STZ-induced diabetic rat model and in TNF-α-stimulated HUVECs. Curcumolide alleviated retinal vascular permeability and leukostasis and attenuated the overexpression of TNF-α and ICAM-1 in diabetic retinas. Moreover, curcumolide also inhibited inducible p38 MAPK and NF-κB activation and the subsequent induction of proinflammatory mediators. These data suggest potential treatment strategies against diabetic retinopathy, particularly in the early stages of the disease.

Topics: Animals; Anti-Inflammatory Agents; Curcuma; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Human Umbilical Vein Endothelial Cells; Leukostasis; Male; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Rats; Rats, Wistar; Sesquiterpenes; Signal Transduction

Curcumin possesses many pharmacological properties including anti-inflammatory effects. Although prior studies indicate that curcumin has beneficial effects for diabetic retinopathy, the mechanism of action is not known. To address this issue, we investigated the effect of curcumin against diabetes-induced retinal vascular damage and its mechanism of action by using cultured retinal Müller cells stimulated with high glucose.. We studied the effects of curcumin in vivo in the retinas of rats rendered diabetic by streptozotocin and in vitro in Müller cells stimulated with high glucose. We administered curcumin, or KN93, an inhibitor of calcium/calmodulin dependent protein kinase II (CaMKII), or saline vehicle to experimental animals on a daily basis for 12 weeks. Primary cultures of rat Müller cells were incubated with normal glucose or high glucose, with or without curcumin, KN93, or pyrrolidine dithiocarbamate (PDTC), an inhibitor of the transcription protein nuclear factor κB (NF-κB). We examined mRNA and protein levels of vascular endothelial growth factor (VEGF), inducible nitric oxide synthase (iNOS) and intercellular adhesion molecule-1 (ICAM-1) by real-time RT-PCR and Western blotting, respectively. Retinal levels of CaMKII and NF-κB were examined by Western blotting. Vascular leakage was evaluated using Evans blue.. Curcumin and KN93 significantly inhibited the activation of CaMKII/NF-κB signaling induced by diabetes or elevated glucose, and subsequently decreased the expression of VEGF, iNOS and ICAM-1. These changes were associated with a decrease of diabetes-induced retinal vascular leakage.. Curcumin protects the diabetic rat retina against early retinal vascular damage, by inhibition of CaMKII activity. Curcumin is currently used to treat a number of clinical conditions, and may prove beneficial for the management of diabetic retinopathy.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Benzylamines; Calcium; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Curcumin; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Ependymoglial Cells; Gene Expression Regulation; Glucose; Intercellular Adhesion Molecule-1; Male; NF-kappa B; Nitric Oxide Synthase Type II; Primary Cell Culture; Pyrrolidines; Rats; Rats, Sprague-Dawley; Retina; Retinal Vessels; Signal Transduction; Sulfonamides; Thiocarbamates; Vascular Endothelial Growth Factor A

The purpose of this study was to evaluate the therapeutic potential of oral curcumin (1 g/kg body weight of rat) in the prevention and treatment of streptozotocin-induced diabetic retinopathy in Wistar albino rats.. The treatment was carried out for a period of 16 weeks in diabetic rats and evaluated for hyperglycemic, antioxidant (superoxide dismutase, catalase, and glutathione), and inflammatory parameters (tumor necrosis factor-α, vascular endothelial growth factor). Rat fundus was observed weekly to see any visible changes in the retina, such as tortuosity and dilation of retinal vessels. Histological changes were evaluated by transmission electron microscopy.. Treatment with curcumin showed significant hypoglycemic activity compared with the diabetic group. Retinal glutathione levels were decreased by 1.5-fold, and antioxidant enzymes, superoxide dismutase and catalase, showed >2-fold decrease in activity in the diabetic group; on the other hand, curcumin positively modulated the antioxidant system. Proinflammatory cytokines, tumor necrosis factor-α and vascular endothelial growth factor, were elevated >2-fold in the diabetic retinae, but prevented by curcumin. Transmission electron microscopy showed degeneration of endothelial cell organelles and increase in capillary basement membrane thickness in diabetic retina, but curcumin prevented the structural degeneration and increase in capillary basement membrane thickness in the diabetic rat retinae.. Based on the above results, it may be concluded that curcumin may have potential benefits in the prevention of retinopathy in diabetic patients.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Basement Membrane; Curcumin; Diabetes Mellitus, Experimental; Diabetic Retinopathy; Hypoglycemic Agents; Male; Microscopy, Electron; Rats; Rats, Wistar; Retina; Streptozocin; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A

Diabetic retinopathy is one of the most devastating microvascular complications of long standing type 1 and type 2 diabetes. Neovascularization stimulated by hyperglycemia-mediated induction of vascular endothelial growth factor (VEGF) has been implicated in the pathogenesis. Various small molecules have been investigated for their ability to inhibit angiogenesis. In this study, we evaluated whether curcumin and its dietary source turmeric can inhibit VEGF expression in strepotzotocin (STZ)-induced diabetic rat retina. Diabetes was induced in 3-month-old male WNIN rats by a single intraperitoneal injection of STZ. After induction, one group of diabetic rats were fed only the AIN-93 diet and the rest of the groups were fed with AIN-93 diet containing 0.002% or 0.01% curcumin or 0.5% turmeric for a period of 8 weeks. The control rats received sham injection and fed on the AIN-93 diet. At the end of 8 weeks animals were sacrificed and retina was dissected. The VEGF expression was analyzed by both real time PCR and immunoblotting. There was an increase in VEGF expression in diabetic retina as compared to control retina at both transcript and protein level. Notably, feeding of curcumin and turmeric to diabetic rats inhibited expression of VEGF. This study highlights the importance of biologically active compounds derived from dietary agents that could be explored further for the prevention and/or treatment of diabetic retinopathy.

Topics: Animals; Curcumin; Diabetic Retinopathy; Gene Expression Regulation; Hyperglycemia; Male; Rats; Retina; Streptozocin; Vascular Endothelial Growth Factor A