Prevention and management of diabetic retinopathy in STZ diabetic rats by Tinospora cordifolia and its molecular mechanisms.

We investigated the potential of Tinospora cordifolia (TC) in treatment of diabetic retinopathy in STZ-induced rats due to its antihyperglycemic, angiogenic, antiinflammatory and antioxidant effects. The diabetic rats, treated for 24 weeks with TC extract (250 mg/kg), were evaluated for lenticular and fundus changes. Biochemical parameters were estimated and histopathological studies performed. TC significantly reduced blood glucose and glycated hemoglobin in treated rats. It prevented cataract development in treated group. Angiogenic markers VEGF and PKC increased in diabetic retina, which reduced significantly with TC. Anti-inflammatory parameters TNF-α and IL-1ß elevated in diabetic group unlike that in treated group. TC also provided defense against depletion of antioxidant enzymes- glutathione and catalase. Histopathological studies revealed thickening of basement membrane of the retinal and glomerular vasculature of diabetic rat, but no basement membrane widening was seen in treated animals. Destruction of pancreatic islet structure was observed in diabetic group, but not in treated. Thus, TC reduces blood glucose and inhibits overexpression of angiogenic and inflammatory mediators, which are distinct markers of diabetic retinopathy. It also prevents retinal oxidative stress and restores antioxidant enzyme levels. These data provide evidence for the safety and potential effect of TC in the management of experimental diabetic retinopathy.

Antifertility activity of methanolic bark extract of Aegle marmelos (l.) in male wistar rats.

BACKGROUND: Aegle marmelos leaf, seed and fruit from earlier studies is known to affect male fertility in reversible manner. However they had delayed onset and recovery was found to be prolonged. The present study was undertaken with an aim to evaluate the effect of Aegle marmelos bark extract on rats as the extract is found to be a rich source of marmin and fagarine known for reducing male fertility. Three different concentration of methanolic bark extracts of Aegle marmelos (L.) were evaluated for male antifertility activity on albino wistar rats. Methanolic bark extract of Aegle marmelos at the dose of 200, 400, and 600 mg/Kg b.w was administered orally for 60 days. Treatments were stopped thereafter and animals were sacrificed after a recovery period of 30 days. Control animal were administered vehicle (0.5% CMC for 60 days). Lonidamine was used as standard drug to compare the effect of extract. RESULTS: Methanolic extract causes a dose & duration dependent infertility via reducing reproductive organ weight and serum testosterone levels. Sperm analysis results showed reduction in sperm density, motility, viability and sperm acrosomal integrity without interfering libido and vital organ body weight. Histopathological studies of testes revealed exfoliation of elongated spermatids, nuclear chromatin condensation, degeneration and prominent spaces detected within the germinal epithelium signifying testicular cytotoxicity and necrosis. Time dependent complete infertility was observed in all dose levels. Animals after the withdrawal from treatment, for 30 days showed restoration of the morphological as well as physiological parameters in extract treated rats. Methanolic extract showed lipid lowering activity compared to control, suggestive good candidature of this plant for further studies. CONCLUSIONS: Our studies suggested Aegle marmelos barks methanolic extract as strong candidate for male contraceptive via its ability to produce complete inhibition of pregnancy, rapid restoration of fertility after withdrawal from treatment and its lipid correcting ability proving further beneficial effects.

Randomised, cross-over, comparative bioavailability trial of matrix type transdermal drug delivery system (TDDS) of carvedilol and hydrochlorothiazide combination in healthy human volunteers: a pilot study.

The present study deals with transdermal drug delivery system (TDDS) of Carvedilol (CRV) and Hydrochlorothiazide (HCTZ). It compares the bioavailability of these two study drugs from a TDDS with conventional immediate release oral tablets in healthy volunteers. The TDDS was also evaluated for any adverse drug reaction. This was an open-label, randomised, single centre, two-treatment, two period, single dose, crossover pilot study of two formulations of cardiovascular agents. Subjects (n=10) were randomised to have a TDDS applied to their abdominal skin for 72h or receive one oral tablet each of CRV and HCTZ respectively in period I, followed by 1-week washout period. They received the alternative treatment in period II. A significant improvement in bioavailability was observed with the transdermal patches over oral tablets as observed by the mean AUC((0)(-)(t)) values 4004.37+/-180.98 and 1824.30+/-17.43ngh/mL respectively for CRV and HCTZ as compared to 753.46+/-53.34 and 392.89+/-34.23ngh/mL respectively, with the oral tablets. The TDDS possesses significant potential for skin irritation. The TDDS developed in our laboratory produced therapeutically effective plasma concentrations of the cardiovascular agents up to a range of 60 to 72h (in different volunteers with a mean=66h). It could be concluded from these observations that the TDDS meets the intended goal of at least 2day management of stage II hypertension with application of a single transdermal patch, hence improving patient compliance over the inconvenience seen with frequent oral administration.

Role of cytokines in anti-implantation activity of H2 receptor blockers in albino Wistar rats.

In this study, the negative effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) on the immune system and body weight gain of rats and the preventive effects of curcumin were examined. For this purpose, 3-4 months old 128 Wistar albino rats with 280-310g body weights were used. The 2microg/kg dose of 2,3,7,8-TCDD and 100mg/kg dose of curcumin were dissolved in corn oil and orally given to the rats found in the experimental and control groups. Then, the serum samples were taken from all rats at 15, 30, 45 and 60th days to analyzed for the determination of TNF-alpha, IFN-gamma, IL-12 and IL-13 levels by ELISA method. The data of body weight gain was measured at 15, 30, 45 and 60th days. The results indicated that 2,3,7,8,3,7,8-TCDD caused to increase significantly (p<0.05) in serum TNF-alpha levels. However, it caused significantly (p<0.05) decreases in the levels of IFN-gamma, IL-12 and IL-13 in rats. On contrary, curcumin increased IFN-gamma, IL-12 and IL-13 levels, but decreased TNF-alpha level in rats. Additionally, TCDD caused significantly (P<0.01) reductions in the body weight gain. However curcumin reversed this effect of TCDD.In conclusion, 2,3,7,8-TCDD significantly suppressed the humoral immunity and body weight gain in rats at doses of 2microg/kg. However curcumin, which was found in some plants, eliminated the effect of TCDD on immune system and body weight when it was given together with 2,3,7,8-TCDD. It is thought that this effect may have occurred via curcumin and TCDD were binding aryl hydrocarbon receptor (AhR) competitively.

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.

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.

Current concepts in the pathophysiology of glaucoma.

Glaucoma, the second leading cause of blindness, is characterized by changes in the optic disc and visual field defects. The elevated intraocular pressure was considered the prime factor responsible for the glaucomatous optic neuropathy involving death of retinal ganglion cells and their axons. Extensive investigations into the pathophysiology of glaucoma now reveal the role of multiple factors in the development of retinal ganglion cell death. A better understanding of the pathophysiological mechanisms involved in the onset and progression of glaucomatous optic neuropathy is crucial in the development of better therapeutic options. This review is an effort to summarize the current concepts in the pathophysiology of glaucoma so that newer therapeutic targets can be recognized. The literature available in the National Medical Library and online Pubmed search engine was used for literature review.

Evaluation of hepatoprotective activity of aerial parts of Tephrosia purpurea L. and stem bark of Tecomella undulata.

ETHNOPHARMACOLOGICAL RELEVANCE: The aerial parts of Tephrosia purpurea (L.) pers. (Fabaceae) and stem bark of Tecomella undulata seem. (Bignoniaceae) are used for liver disorders in the traditional system of medicine. AIM OF THE STUDY: To evaluate the hepatoprotective activity of aerial parts of Tephrosia purpurea and stem bark of Tecomella undulata against thioacetamide-induced hepatotoxicity. MATERIALS AND METHODS: Hepatotoxicity was induced in albino rats of either sex by subcutaneous injection of thioacetamide. Aqueous-ethanolic extract of aerial parts of Tephrosia purpurea (100, 300 and 500 mg/kg/day and ethanolic extract of stem bark of Tecomella undulata (200, 500 and 1000 mg/kg/day were evaluated. RESULTS: Oral administration of Tephrosia purpurea at 500 mg/kg and Tecomella undulata at 1000 mg/kg resulted in a significant reduction in serum aspartate aminotransaminase (35% and 31%, respectively), alanine aminotransaminase (50% and 42%, respectively), gamma glutamyl transpeptidase (56% and 49%, respectively), alkaline phosphatase (46% and 37%, respectively), total bilirubin (61% and 48%, respectively) and liver MDA levels (65% and 50%, respectively), and significant improvement in liver glutathione (73% and 68%, respectively) when compared with thioacetamide damaged rats. Histology of the liver sections of the animals treated with the extracts also showed dose-dependent reduction of necrosis. CONCLUSIONS: The present study demonstrates the hepatoprotective activity of the aerial parts of Tephrosia purpurea and stem bark of Tecomella undulata against thioacetamide-induced hepatotoxicity.

3,4-Disubstituted-1,2,3,4,5,6,7,8-octahydroquinazoline-2-thiones: synthesis, antimicrobial evaluation and QSAR investigations using Hansch analysis.

The 3,4-disubstituted-1,2,3,4,5,6,7,8-octahydroquinazoline-2-thione derivatives were synthesized and characterized by physicochemical and spectral means, and the results of antimicrobial study of these compounds against Staphylococcus aureus, Escherichia coli, and Candida albicans by tube dilution method indicated that 4-(4-chlorophenyl)-3-(4-nitrophenylsulfonyl)-1,2,3,4,5,6,7,8-octahydroquinazoline-2-thione 6 and 4-(4-fluorophenyl)-3-(4-nitrophenylsulfonyl)-1,2,3,4,5,6,7,8-octahydroquinazoline-2-thione 12 were the most potential ones. Further, the QSAR studies by Hansch analysis applied to find out the correlation between physicochemical characteristics of synthesized compounds with antimicrobial activity demonstrated the contribution of electronic parameter, total energy (Te) and the topological parameter (valence second order molecular connectivity index (2 chi v). Excellent statistically significant models were developed by Hansch approach (r2 = 0.828-0.898) for the three microorganisms under study. The cross-validated r2 (q2), which is an indication of the predictive capability of the model for all cases was also very good (q2 = 0.776-0.875).