New drug discovery of cardiac anti-arrhythmic drugs: insights in animal models.

Cardiac rhythm regulated by micro-macroscopic structures of heart. Pacemaker abnormalities or disruptions in electrical conduction, lead to arrhythmic disorders may be benign, typical, threatening, ultimately fatal, occurs in clinical practice, patients on digitalis, anaesthesia or acute myocardial infarction. Both traditional and genetic animal models are: In-vitro: Isolated ventricular Myocytes, Guinea pig papillary muscles, Patch-Clamp Experiments, Porcine Atrial Myocytes, Guinea pig ventricular myocytes, Guinea pig papillary muscle: action potential and refractory period, Langendorff technique, Arrhythmia by acetylcholine or potassium. Acquired arrhythmia disorders: Transverse Aortic Constriction, Myocardial Ischemia, Complete Heart Block and AV Node Ablation, Chronic Tachypacing, Inflammation, Metabolic and Drug-Induced Arrhythmia. In-Vivo: Chemically induced arrhythmia: Aconitine antagonism, Digoxin-induced arrhythmia, Strophanthin/ouabain-induced arrhythmia, Adrenaline-induced arrhythmia, and Calcium-induced arrhythmia. Electrically induced arrhythmia: Ventricular fibrillation electrical threshold, Arrhythmia through programmed electrical stimulation, sudden coronary death in dogs, Exercise ventricular fibrillation. Genetic Arrhythmia: Channelopathies, Calcium Release Deficiency Syndrome, Long QT Syndrome, Short QT Syndrome, Brugada Syndrome. Genetic with Structural Heart Disease: Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia, Dilated Cardiomyopathy, Hypertrophic Cardiomyopathy, Atrial Fibrillation, Sick Sinus Syndrome, Atrioventricular Block, Preexcitation Syndrome. Arrhythmia in Pluripotent Stem Cell Cardiomyocytes. Conclusion: Both traditional and genetic, experimental models of cardiac arrhythmias' characteristics and significance help in development of new antiarrhythmic drugs.

Variable Length Character N-Gram Embedding of Protein Sequences for Secondary Structure Prediction.

BACKGROUND: The prediction of a protein's secondary structure from its amino acid sequence is an essential step towards predicting its 3-D structure. The prediction performance improves by incorporating homologous multiple sequence alignment information. Since homologous details not available for all proteins. Therefore, it is necessary to predict the protein secondary structure from single sequences. OBJECTIVE AND METHODS: Protein secondary structure predicted from their primary sequences using n-gram word embedding and deep recurrent neural network. Protein secondary structure depends on local and long-range neighbor residues in primary sequences. In the proposed work, the local contextual information of amino acid residues captures variable-length character n-gram words. An embedding vector represents these variable-length character n-gram words. Further, the bidirectional long short-term memory (Bi-LSTM) model is used to capture the long-range contexts by extracting the past and future residues information in primary sequences. RESULTS: The proposed model evaluates on three public datasets ss.txt, RS126, and CASP9. The model shows the Q3 accuracy of 92.57%, 86.48%, and 89.66% for ss.txt, RS126, and CASP9. CONCLUSION: The proposed model performance compares with state-of-the-art methods available in the literature. After a comparative analysis, it observed that the proposed model performs better than state-of-the-art methods.

Gum xanthan-psyllium-cl-poly(acrylic acid-co-itaconic acid) based adsorbent for effective removal of cationic and anionic dyes: Adsorption isotherms, kinetics and thermodynamic studies.

The present work highlights the synthesis of the adsorbent based on Gum xanthan-psyllium hybrid backbone graft co-polymerized with polyacrylic acid-co-polyitaconic acid chains for the rapid sequestration of auramine-O (Aur-O) and eriochrome black-T (EBT) dyes from the aqueous fluid. The excellent dye removal efficiency of 90.53% for EBT and 95.63% for Aur-O was found at initial dye concentration of 30mgL-1 (EBT) and 15 mgL-1 (Aur-O) 40mL-1 with an adsorbent dose of 600mg within time duration of 5h and 323K temp. The adsorption isotherm data fitted well with Langmuir isotherm and Freundlich isotherm for Aur-O and EBT dyes (R2 ≥ 0.90), respectively. The adsorption kinetics depicted that pseudo-second order kinetics was followed simultaneously with intra-particle diffusion for both the dyes. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were also calculated and confirmed the spontaneity, randomness and endothermic nature of the adsorption process. Further, the adsorbent exhibited good recyclability efficiency for the capture of Aur-O and EBT from aqueous solution with minimal activity decline after six and three cycles, respectively. So, the synthesized adsorbent could be used successfully by the textile industries for the treatment of dye contaminated water with excellent competency.

Identifying genomic targets for protein over-expression by "omics" analysis of Quiescent Escherichia coli cultures.

BACKGROUND: A cellular stress response is triggered upon induction of recombinant protein expression which feedback inhibits both growth as well as protein synthesis. In order to separate these two effects, it was decided to study "quiescent cultures" which continue to be metabolically active and express recombinant proteins even after growth cessation. The idea was to identify and up-regulate genes which are responsible for protein synthesis in the absence of growth. This would ensure that, even if growth were adversely affected post induction, there would be no attendant reduction in the protein expression capability of the cells. This strategy allowed us to design host strains, which did not grow better post induction but had significantly higher levels of protein expression. RESULTS: A quiescent Escherichia coli culture, which is able to sustain recombinant protein expression in the absence of growth, was analyzed by transcriptomic and proteomic profiling. Many genes involved in carbon utilization, biosynthesis of building blocks and stress protection were found to be up-regulated in the quiescent phase. Analysis of the global regulators showed that fis, which tends to get down-regulated as the cells enter stationary phase, remained up-regulated throughout the non-growing quiescent phase. The downstream genes regulated by fis like carB, fadB, nrfA, narH and queA were also up-regulated in the quiescent phase which could be the reason behind the higher metabolic activity and protein expression ability of these non-growing cells. To test this hypothesis, we co-expressed fis in a control culture expressing recombinant L-asparaginase and observed a significantly higher buildup of L-asparaginase in the culture medium. CONCLUSIONS: This work represents an important breakthrough in the design of a superior host platform where a gene not directly associated with protein synthesis was used to generate a phenotype having higher protein expression capability. Many alternative gene targets were also identified which may have beneficial effects on expression ability.

Visual Outcome of Traumatic Cataract at a Tertiary Eye Care Centre in North India: A Prospective Study.

INTRODUCTION: One of the most common presentations of blunt and penetrating ocular trauma is traumatic cataract. It remains a significant cause of visual impairment and physical disability among adults and children. It is associated with various ocular injuries. AIM: To evaluate the associated ocular injuries and final outcome of patients with traumatic cataract along with their demographic features and modes of trauma. MATERIALS AND METHODS: A prospective study done in Department of Ophthalmology in M.L.B. Medical college, Jhansi from February 2010 to July 2011. A total of 48 patients diagnosed as a case of traumatic cataract were subjected to a detailed history, systemic and local examination with relevant investigations. Medical or surgical managements were done accordingly. Patients were subsequently followed-up and visual acuity was recorded. Appropriate statistical tests were applied. RESULTS: A 54.2% patients sustained penetrating trauma while 45.8% got blunt injury. Out of total, 79% patients were males while 50% were less than 15 years of age. Causative agents were stone, wood items, stick, metal objects etc. Among blunt trauma cases, 64% of the patients had visual acuity <6/60 while among penetrating trauma cases nobody had acuity >6/18. Anterior segment was more involved as compared to posterior segment. A 38.5% patients had corneal opacity among penetrating injury patients. The interval between trauma and surgery was less than one month among 75% of patients. After three months of surgery, 43.7% patients had visual acuity of >6/18. CONCLUSION: This study provides recent data of patients hospitalized after ocular trauma and diagnosed as a case of traumatic cataract. Traumatic cataract occurs mostly in younger males. Surgical intervention is necessary to improve visual outcome. Good visual outcome was obtained in nearly half of the patients. Traumatic cataract patients can have good visual outcome depending upon proper management.

Dual therapy of vildagliptin and telmisartan on diabetic nephropathy in experimentally induced type 2 diabetes mellitus rats.

INTRODUCTION: The objective of this article is to investigate the combination of telmisartan with vildagliptin therapy versus monotherapy of vildagliptin and telmisartan on diabetic nephropathy in type 2 diabetes mellitus rats. MATERIALS AND METHODS: In adult rats streptozotocin (65 mg/kg) and nicotinamide (110 mg/kg) were injected intraperitoneally to produce diabetic nephropathy. Rats of either sex allotted to the following groups: (i) triple therapy: metformin (120 mg/kg, o.d.) + pioglitazone (1.25 mg/kg, o.d.) + glimepiride (0.7 mg/kg, o.d.); (ii) dual therapy: vildagliptin (8.76 mg/kg, o.d.) + telmisartan (6.48 mg/kg, o.d.); (iii) vildagliptin (8.76 mg/kg, o.d.); and (iv) telmisartan (6.48 mg/kg, o.d.); therapy was carried out for 35 days orally. Weekly at days 7, 14, 21, 28 and 35, blood pressure, blood glucose level, body weight, blood serum creatinine level, protein albumin level in urine, and blood urea nitrogen (BUN) were estimated. Renal structural changes were observed. RESULTS: Blood pressure, blood glucose level, blood serum creatinine level, protein albumin level in urine, BUN and renal deterioration increased significantly in diabetic rats compared with normal control rats. The vildagliptin + telmisartan treatment group showed no weight gain and controlled blood pressure, renovascular structural and biochemical parameters in diabetic neuropathy rats. CONCLUSIONS: The addition of telmisartan to vildagliptin demonstrated the best control over blood pressure, glycemia and diabetic nephropathy markers, renal structural changes and improvement of renal function as opposed to monotherapy with either drug, possibly because of the dual inhibitory effect on the renin-angiotensin system.

Design, development and permeation studies of nebivolol hydrochloride from novel matrix type transdermal patches.

BACKGROUND: Nebivolol hydrochloride is a third generation ß-blocker with highly selective ß1-receptor antagonist with antihypertensive properties having plasma half life of 10 h and 12% oral bioavailability. The aim of the present investigation was to form matrix type transdermal patches containing Nebivolol hydrochloride to avoid its extensive hepatic first pass metabolism, lesser side effect and increase bioavailability of drug. MATERIALS AND METHODS: Matrix type transdermal patches containing Nebivolol hydrochloride were prepared using EudragitRS100, HPMC K100M (2:8) polymers by solvent evaporation technique. Aluminum foil was used as a backing membrane. Polyethylene glycol (PEG) 400 was used as plasticizer and Dimethyl sulfoxide (DMSO) was used as a penetration enhancer. Drug polymer interactions determined by FTIR and standard calibration curve of Nebivolol hydrochloride were determined by using UV estimation. RESULT: The systems were evaluated physicochemical parameters and drug present in the patches was determined by scanning electron microscopy. All prepared formulations indicated good physical stability. In vitro drug permeation studies of formulations were performed by using Franz diffusion cells using abdomen skin of Wistar albino rat. Result showed best in vitro skin permeation through rat skin as compared to all other formulations prepared with hydrophilic polymer containing permeation enhancer. CONCLUSIONS: IT WAS OBSERVED THAT THE FORMULATION CONTAINING HPMC: EudragitRS100 (8:2) showed ideal higuchi release kinetics. On the basis of in vitro drug release through skin permeation performance, Formulation F1 was found to be better than other formulations and it was selected as the optimized formulation.

Gemfibrozil and its combination with metformin on pleiotropic effect on IL-10 and adiponectin and anti-atherogenic treatment in insulin resistant type 2 diabetes mellitus rats.

AIM: Gemfibrozil is a PPAR-α ligand that inhibits the progression of atherosclerosis in insulin resistance type 2 diabetes mellitus (IR type 2 DM). Gemfibrozil, poor anti-hyperglycemic combined with metformin, evaluated for MMP-9, IL-10 and adiponectin beyond glycemic control. ESSENTIAL METHODS: IR type 2 DM induced by administering streptozotocin (90 mg/kg, i.p.) in neonatal rat model. IR type 2 DM rats at 6-week age treated for 8 weeks with (1) gemfibrozil (140 mg/kg od) and (2) gemfibrozil (70 mg/kg bid) + metformin (60 mg/kg bid). At the end, risk parameters like MMP-9, IL-10 and adiponectin were evaluated by ELISA kits. MAIN RESULTS: Gemfibrozil reduced the MMP-9 levels (-25.740 %) (106.772 ± 7.201 ng/ml vs. 80.231 ± 7.023 ng/ml, P < 0.01); increased adiponectin (68.321 %) (8.781 ± 1.111 µg/ml vs. 14.782 ± 1.055 µg/ml) and IL-10 (155.687 %) (334.208 ± 26.307 pg/ml vs. 853.472 ± 23.172 pg/ml, P < 0.001), but poor glycemic control (-6.169 %) (167.5 ± 16.037 vs. 157.167 ± 3.911, P = ns), hence combined with metformin showed synergistic activity, reduced the MMP-9 levels (-16.992 %) (106.772 ± 7.201 ng/ml vs. 89.941 ± 8.636 ng/ml, P < 0.05) and increased adiponectin (39.870 %) (8.781 ± 1.111 µg/ml vs. 12.282 ± 0.782 µg/ml) and, IL-10 (80.136 %) (334.208 ± 26.307 pg/ml vs. 602.029 ± 39.668 pg/ml, P < 0.01) had good glycemic control (-28.856 %) (167.5 ± 16.037 mg/dl vs. 129.167 ± 4.214 mg/dl, P < 0.05). OVERALL CONCLUSIONS: Gemfibrozil plus metformin decrease MMP-9, increase IL-10 and adiponectin acting as anti-atherogenic, anti-inflammatory and immunomodulatory in IR type 2 DM.

Hypoglycemic effects of Citrullus colocynthis roots.

The aim of this study was to examine the effect of root of C. colocynthis on the biochemical parameters of normal and alloxan-induced diabetic rats. Diabetes mellitus was induced by intraperitoneal (120 mg/kg b.w.) injection of alloxan monohydrate for three days and the animals showing blood glucose level in the range of 175-300 mg/dL were selected for study. The blood glucose concentrations of the animals were measured at the beginning of the study and the measurements were repeated on 3rd, 5th and 7th day after the start of the experiment. On day 7, blood was collected by cardiac puncture under mild ether anesthesia. Aqueous extract of roots of Citrullus colocynthis showed significant reduction in blood sugar level (58.70%) when compared with chloroform (34.72%) and ethanol extracts (36.60%) (p < 0.01). The aqueous extracts showed improvement in parameters like body weight, serum creatinine, serum urea and serum protein as well as lipid profile and also restored the serum level of bilirubin total, conjugated bilirubin, serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transminase (SGPT) and alkaline phosphatase (ALP).

Involvement of adenosine and standardization of aqueous extract of garlic (Allium sativum Linn.) on cardioprotective and cardiodepressant properties in ischemic preconditioning and myocardial ischemia-reperfusion induced cardiac injury.

The present study investigated the effect of garlic (Allium sativum Linn.) aqueous extracts on ischemic preconditioning and ischemia-reperfusion induced cardiac injury, as well as adenosine involvement in ischemic preconditioning and garlic extract induced cardioprotection. A model of ischemia-reperfusion injury was established using Langendorff apparatus. Aqueous extract of garlic dose was standardized (0.5%, 0.4%, 0.3%, 0.2%, 0.1%, 0.07%, 0.05%, 0.03%, 0.01%), and the 0.05% dose was found to be the most effective. Higher doses (more than 0.05%) were highly toxic, causing arrhythmia and cardiodepression, whereas the lower doses were ineffective. Garlic exaggerated the cardioprotective effect of ischemic preconditioning. The cardioprotective effect of ischemic preconditioning and garlic cardioprotection was significantly attenuated by theophylline (1,000 µmol/L) and 8-SPT (10 mg/kg, i.p.) and expressed by increased myocardial infarct size, increased LDH level, and reduced nitrite and adenosine levels. These findings suggest that adenosine is involved in the pharmacological and molecular mechanism of garlic induced cardioprotection and mediated by the modulation of nitric oxide.

Sitagliptin, sitagliptin and metformin, or sitagliptin and amitriptyline attenuate streptozotocin-nicotinamide induced diabetic neuropathy in rats.

Diabetic neuropathies are a family of nerve disorders caused by diabetes. Symptoms of the disease include nerve palsy, mononeuropathy, mononeuropathy multiplex, diabetic amyotrophy, painful polyneuropathy, autonomic neuropathy, and thoracoabdominal neuropathy. In this study, type 2 diabetes in rats was induced with nicotinamide-streptozotocin. Drug treatment was initiated on the d 15, with the combination regimen of metformin, pioglitazone and glimipiride or metformin and sitagliptin or sitagliptin, amitriptyline and sitagliptin and led to significantly improved glycemic control, increased grip strength and paw jumping response on d 21, 28 and 35 (P < 0.001). Significant increases in blood protein levels and decreases in urinary protein levels were observed in the animals treated with the different regimens on d 21, 28 and 35 (P < 0.001). Combined treatment of streptozotocin and nicotinamide caused marked degeneration of nerve cells, while administration of metformin and sitagliptin showed tissue regeneration and no body weight gain. In conclusion, treatment with sitagliptin and sitagliptin combined with metformin or amitriptyline results in no body weight gain, but causes an increase in grip strength and pain sensitivity, exhibits neural protection, and reverses the alteration of biochemical parameters in rats with streptozotocin-nicotinamide induced type 2 diabetes.

Pharmacological studies on seeds of Alangium salvifolium Linn.

The seeds of Alangium salvifolium Linn. have been traditionally reported to exhibit a variety of biological activities, including antidiabetic, anticancer, diuretic, anti-inflammatory, antimicrobial, laxative, and antiepileptic activities. The objective of this study was to verify the traditional claims and to evaluate the seeds of Alangium salvifolium in various organic extracts to screen the antidiabetic, antiepileptic, analgesic and antiinflammatory activities. The chloroform, ethanol, and water extracts of Alangium salvifolium seeds were obtained and subjected for phytochemical screening and evaluated for their pharmacological activities. From the acute toxicity study it was observed that chloroform, ethanol, and aqueous extracts of Alangium salvifolium seeds are non-toxic at a fixed dose of 2000 mg/kg. Among all three extracts ethanol extracts exhibited significant (p < 0.01) antidiabetic, antiepileptic, analgesic and anti-inflammatory activities. The phytochemical analysis revealed the presence of alkaloids, glycosides, terpenoids, steroids and tannins. The results of present study verified the traditional claims made by ayurvedic practitioner. However, the chemical constituents responsible for the pharmacological activities remain to be investigated.

Cardioprotective activity of alcoholic extract of Tinospora cordifolia (Willd.) Miers in calcium chloride-induced cardiac arrhythmia in rats.

The present study investigated the antiarrhythmic activity of alcoholic extract of Tinospora cordifolia (T. cordifolia) in CaCl2 induced arrhythmia. CaCl2 (25 mg/kg) was administered by intravenous infusion (iv) to produce arrhythmia in rats. The animals were then treated with T. cordifolia extract (150, 250, and 450 mg/kg) and verapamil (5 mg/kg,iv). Lead II electrocardiogram was monitored. Plasma calcium, sodium and potassium levels were measured. In CaCl2 induced arrhythmia, heart rate was decreased by 41.10%, T. cordifolia at 150, 300, and 450 mg/kg decreased the heart rate by 26.30%, 29.16%, and 38.29%, respectively, and verapamil reduced the heart rate by 9.70% compared to the normal group. The PQRST waves were normalized and atrial and ventricular fibrillation was controlled in rats treated with verapamil and T. cordifolia. CaCl2 increased calcium and sodium levels and decreased potassium levels in blood. T. cordifolia dose-dependently decreased calcium and sodium levels and increased potassium levels. Hence, T. cordifolia can be used in antiarrhythmic clinical settings and beneficial in atrial and ventricular fibrillation and flutter and may be indicated in ventricular tachyarrhythmia.

CNS activity of aqueous extract of root of Cissus quadrangularis Linn. (Vitaceae).

In Ayurveda, Cissus quadrangularis Linn. is used to treat anorexia, asthma, sickle cell, colds, pain, and malaria. Aqueous C. quadrangularis extract was evaluated in vivo for its antiepileptic activity by using the maximal electroshock and isonicotinic hydrazide acid models, for its analgesic activity by using the hot plate method, and for its smooth muscle relaxant activity by using the rotarod method. Adult male Swiss mice were used for this study and animals were divided into 6 animals per group. Doses of 250 mg/kg body weight and 500 mg/kg body weight protected the mice against maximal electroshock seizure, and delayed the onset time of seizures induced by isonicotinic hydrazide acid. Prominent analgesic activity was observed using the hot plate method. The paw licking time was delayed significantly. The extract also displayed prominent smooth muscle relaxant activity. The results suggest that the aqueous extracts of C. quadrangularis roots possess anticonvulsant, analgesic, and smooth muscle relaxant properties.

Triple verses glimepiride plus metformin therapy on cardiovascular risk biomarkers and diabetic cardiomyopathy in insulin resistance type 2 diabetes mellitus rats.

IRtype2DM patients are often treated with a combination of antidiabetic agents. Drugs with different complementary mechanisms of action frequently used in daily clinical practice but glycemic control with monotherapeutic attempts fail in the long run. To date, biomarkers for cardiovascular risk and insulin sensitivity with combination of triple oral hypoglycemic therapies are not fully revelled in view of additional cardiovascular risk reduction. In the present study, IRtype2DM induced by administering streptozotocin (90 mg/kg, i.p.) in neonatal rat model. IRtype2DM rats were selected by determining FPI [>60 pmol/l]; HOMA-IR & Hyperinsulinemic euglycemic clamp technique at 6 weeks and then treated for 8 weeks with (i) Metformin (120 mg/kg, o.d.)+Glimepiride (1mg/kg, o.d.), (ii) Metformin (265 mg/kg, o.d.)+Rosiglitazone (1mg/kg, o.d.)+Glimepiride (0.7 mg/kg, o.d.). At the end cardiovascular risk parameters evaluated by ELISA kits and insulin sensitivity were determined by HOMA-IR. In conclusion, triple oral hypoglycemic therapy improves glycemic control, insulin sensitivity, retards diabetic cardiomyopathy and does not increased body weight; decrease more detrimental inflammatory markers, increase interleukin-10 and adiponectin in neonatal streptozotocin-induced IRtype2DM Wistar Albino Rats. Triple therapy showed a synergistic effect and was promising in insulin resistance, better in additional cardiovascular risk reduction and those nonresponders to metformin add on glimepiride therapy.