Fabrication and Validation of Gyro-Dot-Optomotor Response Device using Gold Fish to Study Drugs Affecting Visual Perception.

An appropriate model to predict the effect of xenobiotics on the vision perception in neuropsychoharmacological studies is of great importance in drug development and toxicity studies. The present study valuated the effect of CNS stimulant, depressant and therapeutic agents known to have ocular toxicity on ptomotor response (OMR) using goldfish in a newly developed device. A digital light processing aided gyrating poly-chromatic dotted pattern-OMR (Gyro-dot-OMR) analyzer was developed and standardized for this study in our laboratory. Goldfishes were exposed to varying concentrations of caffeine and pentobarbitone sodium to evaluate the effect of CNS stimulation and depression on OMR in white light. Ethambutol induced ocular toxicity was evaluated by intravitreal injection into both eyes of goldfishes. They were subjected for polychromatic Gyro-dot-OMR in both clock and anticlockwise directions. At the low concentration (5, 10 and 20 ng/mL) caffeine exposed animals showed significant (p<0.05) stimulant effect and the EC(50) of caffeine in goldfish was found to be 4.806 ng/mL. In contrast, pentbbarbitone sodium treated fishes showed significant (p<0.05) depressant effect with increasing the concentration. Ethambutol toxicity was reflected by the color iscrimination in the Gyro-dot-OMR pattern. For the first time, this model proved the possibility of running Irwin profile test on goldfish using Gyro-dot-OMR. This model successfully predicted ethambutol induced toxicity with poor discrimination of red-green color. This model can be used for predicting toxicity of drugs affecting vision perception.

Effects of Trigonella foenum-graecum (L.) on retinal oxidative stress, and proinflammatory and angiogenic molecular biomarkers in streptozotocin-induced diabetic rats.

The aim of the present study was to investigate the protective effects of Trigonella foenum-graecum Linn. (fenugreek) in Streptozotocin-induced diabetic rat retina. Fenugreek (100 and 200 mg/kg body weights) treatment was carried out for 24 weeks and evaluated for inflammatory [tumor necrosis factor (TNF)-α and interleukin (IL)-1ß] and angiogenic [vascular endothelial growth factor (VEGF) and protein kinase C (PKC)-ß] molecular biomarkers. Retinal oxidative stress was evaluated by estimating antioxidant (Glutathione, Superoxide dismutase, and Catalase) parameters. Fluorescein angiography was performed to detect retinal vascular leakage. Electron microscopy was performed to determine basement membrane thickness. In the present study, significant rises in the expressions of retinal inflammatory (TNF-α and IL-1ß) and angiogenic (VEGF and PKC-ß) molecular biomarkers were observed in diabetic retinae compared with normal retinae. However, fenugreek-treated retinae showed marked inhibition in the expression of inflammatory and angiogenic molecular biomarkers. Moreover, results from the present study showed positive modulatory effects of fenugreek on retinal oxidative stress. Fluorescein angiograms and fundus photographs obtained from diabetic retinae showed retinal vascular leakage. On the other hand, fenugreek-treated retinae did not show vascular leakage. Further, thickened BM was recorded in diabetic retina compared with normal retinae. However, fenugreek-treated retinae showed relatively lesser thickening of capillary BM. In conclusion, it may be postulated that fenugreek has great potential in preventing diabetes-induced retinal degeneration in humans after regular consumption in the specified dosage.

Retinoprotective effects of Moringa oleifera via antioxidant, anti-inflammatory, and anti-angiogenic mechanisms in streptozotocin-induced diabetic rats.

PURPOSE: The present study was aimed to evaluate the retinoprotective effects of Moringa oleifera (MO) in Streptozotocin-induced diabetic rats. METHODS: The study was continued for 24 weeks and evaluated for inflammatory (tumor necrosis factor [TNF]-α and interleukin [IL]-1ß, angiogenic (vascular endothelial growth factor [VEGF] and protein kinase C [PKC]-ß) and antioxidant (Glutathione, Superoxide dismutase, and Catalase) parameters. Retinal leakage was checked by Fluorescein angiography (FA) and fundus photographs were evaluated for retinal vessel caliber (arteriolar and venular). Transmission electron microscopy was done to determine basement membrane (BM) thickness. RESULTS: The results of the present study showed potential hypoglycemic and retinal antioxidant effects of MO. In the present study, a significant rise in the expression of retinal inflammatory (TNF-α and IL-1ß) and angiogenic (VEGF and PKC-ß) parameters was observed in diabetic retinae as compared to normal retinae. However, MO-treated retinae showed marked inhibition in the expression of inflammatory and angiogenic parameters. Further, in the present study, diabetic retinae showed dilated retinal vessels as compared to normal. However, MO-treated retinae showed marked prevention in the dilatation of retinal vessels. Fluorescein angiograms obtained from diabetic retinae showed leaky and diffused retinal vasculature. On the other hand, MO-treated retinae showed intact retinal vasculature. Further, results of the transmission electron microscopy study showed thickened capillary BM in the diabetic retina as compared to normal retinae. However, treatment with MO prevented thickening of capillary BM. CONCLUSION: Our result suggests that MO may be useful in preventing diabetes induced retinal dysfunction.

Green tea prevents hyperglycemia-induced retinal oxidative stress and inflammation in streptozotocin-induced diabetic rats.

PURPOSE: Our objective was to investigate the effect of green tea (GT) on diabetes-induced retinal oxidative stress and proinflammatory parameters in rats. METHODS: Treatment (200 mg/kg body weight) was carried out for a period of 16 weeks in streptozotocin-induced diabetic rats and was evaluated for hypoglycemic, antioxidant [reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT)] and anti-inflammatory [tumor necrosis factor (TNF) α, vascular endothelial growth factor (VEGF)] activity. Histological changes were evaluated by transmission electron microscopy. RESULTS: Retinal GSH levels were 1.5-fold lower in diabetic rats as compared to normal rats (p < 0.05). However, in GT-treated rats, retinal GSH levels were restored close to those of the normal group. The antioxidant enzymes SOD and CAT showed a more than 2-fold decrease in activity in diabetic retinae as compared to normal retinae (p < 0.05). Both SOD and CAT enzymatic activities were restored close to normal in the GT-treated group. Expression of proinflammatory parameters (TNF-α and VEGF) was significantly inhibited in GT-treated retinae as compared to diabetic retinae (p < 0.05). Moreover, GT treatment prevented retinal capillary basement membrane thickness. CONCLUSION: The beneficial effects of GT suggest its potential role in the prevention and treatment of diabetic retinopathy in human subjects.

Evaluation of anticataract potential of Triphala in selenite-induced cataract: In vitro and in vivo studies.

Triphala (TP) is composed of Emblica officinalis, Terminalia chebula, and Terminalia belerica. The present study was undertaken to evaluate its anticataract potential in vitro and in vivo in a selenite-induced experimental model of cataract. In vitro enucleated rat lenses were maintained in organ culture containing Dulbecco's Modified Eagles Medium alone or with the addition of 100µM selenite. These served as the normal and control groups, respectively. In the test group, the medium was supplemented with selenite and different concentrations of TP aqueous extract. The lenses were incubated for 24 h at 37°C. After incubation, the lenses were processed to estimate reduced glutathione (GSH), lipid peroxidation product, and antioxidant enzymes. In vivo selenite cataract was induced in 9-day-old rat pups by subcutaneous injection of sodium selenite (25 µmole/kg body weight). The test groups received 25, 50, and 75 mg/kg of TP intraperitoneally 4 h before the selenite challenge. At the end of the study period, the rats' eyes were examined by slit-lamp. TP significantly (P < 0.01) restored GSH and decreased malondialdehyde levels. A significant restoration in the activities of antioxidant enzymes such as superoxide dismutase (P < 0.05), catalase (P < 0.05), glutathione peroxidase (P < 0.05), and glutathione-s-transferase (P < 0.005) was observed in the TP-supplemented group compared to controls. In vivo TF 25mg/kg developed only 20% nuclear cataract as compared to 100% in control. TP prevents or retards experimental selenite-induced cataract. This effect may be due to antioxidant activity. Further studies are warranted to explore its role in human cataract.

Trigonella foenum-graecum (Fenugreek) protects against selenite-induced oxidative stress in experimental cataractogenesis.

Cataract is the opacification in eye lens and leads to 50% of blindness worldwide. The present study was undertaken to evaluate the anticataract potential of Trigonella foenum-graecum Linn seeds (fenugreek) in selenite-induced in vitro and in vivo cataract. In vitro enucleated rat lenses were maintained in organ culture containing Dulbecco's modified Eagles medium (DMEM) alone or in addition with 100 microM selenite and served as the normal and control groups, respectively. For the test group, the medium was supplemented with selenite and T. foenum-graecum aqueous extract. The lenses were incubated for 24 h at 37 degrees C. After incubation, the lenses were processed for the estimation of reduced glutathione (GSH), lipid peroxidation product (malondialdehyde), and the antioxidant enzymes. In vivo selenite cataract was induced in 9-day-old rats by subcutaneous injection of sodium selenite (25 micromol/kg body weight). Animals in the test group were injected with different doses of aqueous extract of T. foenum-graecum 4 h before the selenite challenge. A fall in GSH and a rise in malondialdehyde levels were observed in control as compared to normal lenses. T. foenum-graecum significantly (P < 0.01) restored glutathione and decreased malondialdehyde levels. A significant restoration in the activities of antioxidant enzymes such as superoxide dismutase (P < 0.01), catalase, (P < 0.01), glutathione peroxidase (P < 0.01), and glutathione-S-transferase (P < 0.01) was observed in the T. foenum-graecum supplemented group as compared to control. In vivo, none of the eyes was found with nuclear cataract in treated group as opposed to 72.5% in the control group. T. foenum-graecum protects against experimental cataract by virtue of its antioxidant properties. Further studies are warranted to explore its role in human cataract.

Intraocular pressure-lowering activity of topical application of Aegle marmelos fruit extract in experimental animal models.

AIM: The present study was designed to evaluate the intraocular pressure (IOP)-lowering activity of topical application of the aqueous extract of Aegle marmelos fruit in experimental animal models. MATERIALS AND METHODS: New Zealand white rabbits with normal and experimentally elevated IOP using water loading and steroid-induced models were included in this study. The IOP-lowering effect of A. marmelos fruit extract in rabbits with experimentally elevated IOP was also compared with that of timolol 0.25%. RESULTS: In rabbits with normal IOP, the A. marmelos fruit extract at a concentration of 1% showed the maximum IOP-lowering effect with 22.81% reduction from baseline IOP. The maximum IOP reduction achieved in water loading and steroid-induced models with the same concentration of A. marmelos was 27.57 and 28.41% from baseline, respectively. The efficacy was comparable to that of timolol after 45 min of water loading in the water loading model, and during the first 2 h of treatment in the steroid-induced model. CONCLUSION: A. marmelos fruit extract showed significant IOP-lowering activity in experimental animal models.

Oculohypotensive effects of foeniculum vulgare in experimental models of glaucoma.

PURPOSE: Evaluation of oculohypotensive activity of single drop application of aqueous extract of Foeniculum vulgare in experimental models of glaucoma. METHODS: The evaluation of oculohypotensive activity of Foeniculum vulgare was done in rabbits with normal intraocular pressure (IOP) and with experimentally elevated IOP. The experimental increase in IOP was achieved using water loading and steroid induced glaucoma models. RESULTS: The aqueous seed extract of Foeniculum vulgare exhibited 17.49, 21.16 and 22.03% reduction of intraocular pressure (IOP) in normotensive rabbits at 0.3%, 0.6% and 1.2% (w/v) concentrations respectively. The 0.6% concentration was further evaluated in acute and chronic models of glaucoma. A maximum mean difference of 31.20% was observed between vehicle treated and extract treated eyes in water loading model while a maximum mean IOP lowering of 31.29% was observed in steroid induced model of glaucoma. CONCLUSIONS: The aqueous extract of Foeniculum vulgare possesses significant oculohypotensive activity, which was found to be comparable to that of timolol. Further investigations into the mechanism of action, possible toxicity and human clinical trials are warranted before the Foeniculum vulgare finds place in the arsenal of antiglaucoma drugs prescribed by physicians.

Lowering of intraocular pressure by topical application of Daucus carota seed extract in rabbits.

In normotensive rabbits topical application of Daucus carota seed extract at the concentration of 0.3, 0.6 and 1.2% resulted in mean IOP reduction of 19.33. 23.20 and 25.61% respectively from baseline. As no significant difference was observed between the change in IOP in 0.6 and 1.2% extract treated groups, 0.6% concentration was chosen for further evaluation in rabbits with experimentally elevated IOP. In water loaded rabbits, maximum mean IOP reduction with 0.6% extract was 29.39%, which was comparable to pilocarpine. In steroid pretreated rabbits, maximum mean IOP reduction was 30.27% from baseline, which was significantly higher than pilocarpine. The extract showed a comparatively slower onset of action however, the duration of action was comparable to pilocarpine in all the experimental models.

The anti-inflammatory effects of Curcuma longa and Berberis aristata in endotoxin-induced uveitis in rabbits.

PURPOSE: To investigate the anti-inflammatory effect of topical application of Curcuma longa (C. longa) and Berberis aristata (B. aristata) aqueous extracts on experimental uveitis in the rabbit. METHODS: Anterior uveitis was induced in rabbits by intravitreal injection of lipopolysaccharide from Escherichia coli after pretreatment with C. longa and B. aristata aqueous extracts. Subsequently, the anti-inflammatory activity of C. longa and B. aristata was evaluated by grading the clinical signs and histopathologic changes and estimating the inflammatory cell count, protein, and TNF-alpha levels in the aqueous humor. RESULTS: The anterior segment inflammation in the control group was significantly higher than in both the extract-treated groups, as observed by clinical and histopathologic grading. The inflammatory cell count in the control group was 30.75 +/- 7.33 x 10(5) cells/mL, whereas it was 2.39 +/- 0.59 x 10(5) (P < 0.001 vs. control) and 11.56 +/- 2.44 x 10(5) (P = 0.001 vs. control) cells/mL in the C. longa- and B. aristata-treated groups, respectively. The protein content of the aqueous humor was 18.14 +/- 4.98, 3.16 +/- 0.55 (P < 0.001 vs. control), and 8.24 +/- 1.42 (P < 0.01 vs. control) mg/mL in the control, C. longa-, and B. aristata-treated groups, respectively. The aqueous TNF-alpha level in the control group was 976.29 +/- 66.38 pg/mL and was 311.96 +/- 28.50 (P < 0.0001 vs. control) and 654.09 +/- 47.66 (P < 0.001vs. control) pg/mL in the C. longa- and B. aristata-treated groups, respectively. CONCLUSIONS: Topical instillation of aqueous extracts of C. longa and B. aristata showed potent anti-inflammatory activity against endotoxin-induced uveitis in rabbits.

Comparative evaluation of megadose methylprednisolone with dexamethasone for treatment of primary typical optic neuritis.

AIM: To compare the efficacy of intravenous methylprednisolone and intravenous dexamethasone on visual recovery and evaluate their side-effects for the treatment of optic neuritis. MATERIALS AND METHODS: Prospective, randomized case-controlled study including 21 patients of acute optic neuritis presenting within eight days of onset and with visual acuity less then 20/60 in the affected eye who were randomly divided into two groups. Group I received intravenous dexamethasone 200 mg once daily for three days and Group II received intravenous methylprednisolone 250 mg/six-hourly for three days followed by oral prednisolone for 11 days. Parameters tested were pupillary reactions, visual acuity, fundus findings, color vision, contrast sensitivity, Goldmann visual fields and biochemical investigations for all patients at presentation and follow-up. RESULTS: Both groups were age and sex-matched. LOGMAR visual acuity at presentation was 1.10 +/- 0.52 in Group I and 1.52 +/- 0.43 in Group II. On day 90 of steroid therapy, visual acuity improved to 0.28 +/- 0.33 in Group I and 0.36 +/- 0.41 in Group II ( P =0.59). At three months there was no statistically significant difference in the color vision, contrast sensitivity, stereoacuity, Goldman fields and the amplitude and latency of visually evoked response between the two groups. The concentration of vitamin C, glucose, sodium, potassium, urea and creatinine were within the reported normal limits. CONCLUSION: Intravenous dexamethasone is an effective treatment for optic neuritis. However, larger studies are required to establish it as a safe, inexpensive and effective modality for the treatment of optic neuritis.

Use of the Unfolder Silver/Sapphire system to inject capsular tension ring during phacoemulsification in cases with subluxated cataract.

Capsular tension rings (CTRs) have proved to be useful devices in cataract surgery in cases of zonular weakness and dialysis. They can be inserted with the help of forceps or commercially available injection systems. We describe use of the Unfolder Silver/Sapphire Series implantation system (Advanced Medical Optics, Inc.) to inject a CTR into the capsular bag during phacoemulsification in cases with subluxated cataract. The implantation system used for CTR insertion can subsequently be used for implantation of a foldable intraocular lens.

Effect of iron on lipid peroxidation, and enzymatic and non-enzymatic antioxidants and bacoside-A content in medicinal plant Bacopa monnieri L.

The effect of Fe was investigated in medicinally important plant, Bacopa monnieri L. and the response on malondialdehyde (MDA) content, superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX) was found different in roots and leaves of the metal treated plants. Iron induced stress was observed as indicated by high level of lipid peroxidation, being more steep increase in leaves than roots. In roots, SOD activity was found to increase in metal treated plants except 80 and 160 microM at 72 h, whereas, it decreased in leaves except 10 and 40 microM after 48 h as compared to their respective controls. Among H2O2 eliminating enzymes, POD activity increased in roots, however, it decreased in leaves except at 10 and 40 microM Fe after 48 h as compared to control. At 24 and 48 h, APX activity and ascorbic acid content followed the similar trend and were found to increase in both parts of the metal treated plants as compared to their respective controls. The level of cysteine content in the roots increased at initial period of exposure; however, no marked change in its content was noticed in leaves. In both roots and leaves, non-protein thiol content was found to increase except at higher metal concentrations at 72 h. The data of proline content have shown significant (p<0.01) increase at 40 microM onwards in both part of the plants after 48 and 72 h. Correlation coefficient was evaluated between metal accumulations with various parameters and also between different antioxidant parameters with MDA. Since the level of bacoside-A (active constituent) content in metal treated plants increases, therefore, it is advisable to assess the biological activity of the plants before using for medicinal purposes, particularly in developing countries.