Nidhi Bharal Agarwal

Effect of lamotrigine, oxcarbazepine and topiramate on cognitive functions and oxidative stress in PTZ-kindled mice

Cognitive impairment is frequently observed in epileptic patients. It has been seen that not only epilepsy but antiepileptic drugs also impair cognitive functions. The present study was undertaken to assess the effect of three anticonvulsants viz. lamotrigine (5mg/kg, p.o.), oxcarbazepine (15mg/kg, p.o.) and topiramate (10mg/kg, p.o.) on cognitive function and oxidative stress during pentylenetetrazole (PTZ)-kindling in mice. Kindling was induced by the administration of PTZ (25mg/kg, i.p.) on every alternate day till 5 weeks. Cognition was assessed after the development of kindling. Elevated plus maze (EPM) and passive avoidance response (PAR) tests were carried out after 24h and 48h of the last PTZ administration. After completion of behavioural tests malondialdehyde (MDA), glutathione levels, superoxide dismutase and catalase activity were measured as an indicator of oxidative stress. The results of the present study indicate that topiramate (10mg/kg) administration to kindled animals increased transfer latency and decreased step-down latency in EPM and PAR tests, respectively. However, lamotrigine and oxcarbazepine did not alter the two parameters. Topiramate administration to kindled as well as non-kindled animals has shown increase in MDA and decrease in glutathione levels. Lamotrigine and oxcarbazepine did not show significant alteration in oxidative stress parameters. To conclude, long term administration of topiramate impairs cognitive functions during experimental epilepsy while lamotrigine and oxcarbazepine are safer.

Modulation of pentylenetetrazole-induced kindling and oxidative stress by curcumin in mice

Epilepsy is a chronic neurological disorder affecting 1% population worldwide. A number of experimental studies have reported anticonvulsant, neuroprotective and antioxidant activity of certain natural products like curcumin, an active ingredient of turmeric. The present study was designed to explore the effect of acute administration of curcumin at doses 50, 100 and 200 mg/kg, orally (p.o.) pentylenetetrazole-induced kindling in mice. Further two oxidative stress markers viz., malondialdehyde (MDA) and glutathione were estimated in brain tissues of rodents. Curcumin (50, 100 and 200 mg/kg, p.o.) dose dependently suppressed the progression of kindling in mice. In addition, the increased levels of MDA and glutathione were also reduced by curcumin in kindled animals. These results suggest that curcumin appears to possess protective activity against kindling in mice.

Atorvastatin prevents development of kindling by modulating hippocampal levels of dopamine, glutamate, and GABA in mice

PURPOSE Atorvastatin (ATV) is widely used for the treatment of dyslipidemias. Recent evidence has shown that ATV has protection effects against seizures. However, the effect of ATV on certain neurotransmitter and oxidative stress markers associated with seizures had not been reported. Therefore, the present study aimed to evaluate the effects of ATV on oxidative stress markers on whole brain and GABA, glutamate, and dopamine levels in the hippocampus of PTZ-kindled mice. Additionally, effects of ATV on animal models of seizures, anxiety, and depression were also assessed. MATERIALS AND METHODS Swiss albino mice were given ATV (20, 40, and 80mg/kg/p.o.) in an acute study. On the seventh day, animals were subjected to various neurological and neurobehavioral tests, viz, increasing current electroshock (ICES) test, pentylenetetrazole (PTZ)-induced seizures, Elevated Plus Maze (EPM), and Forced Swim Test (FST). For the development of kindling, a subconvulsant dose of PTZ, i.e., 25mg/kg, i.p., was administered every other day, and ATV in all the three doses was administered daily. Seizure score was continuously monitored until the development of kindling. Thiobarbituric acid reacting species (TBARS), glutathione, dopamine, GABA, and glutamate levels were also assessed in the brain tissues of mice. RESULTS The results showed that in the ICES test, ATV 80mg/kg increased the seizure threshold to hind limb extension (HLE), and a complete protection against HLE was observed when ATV 80mg/kg was combined with a subanticonvulsant dose of phenytoin. Atorvastatin in all the tested doses suppressed the development of kindling, reduced lipid peroxidation, and increased glutathione levels. All doses of ATV maintained the normal levels of glutamate, GABA, and dopamine in kindled mice. CONCLUSION Atorvastatin possesses anticonvulsant activity against electroconvulsions. It was found to suppress the development of PTZ kindling, presumably altering the redox status and hippocampal levels of dopamine, glutamate, and GABA.

Resveratrol suppressed seizures by attenuating IL-1β, IL1-Ra, IL-6, and TNF-α in the hippocampus and cortex of kindled mice

Objective: There is an urge to identify new molecules which can modulate process of epileptogenesis, since currently available drugs act symptomatically and one-third of the patients remain refractory to the disease. Hence, the present study was conducted to evaluate the effects of Resveratrol (RESV) on epileptogenesis in pentylenetetrazole (PTZ)-induced kindling in mice. Method: Swiss albino mice were administered RESV (10, 20 and 40 mg/kg,p.o) in acute study. On the seventh day animals were subjected to various neurological and neurobehavioral tests viz, Increasing Current Electroshock Test (ICES), PTZ-induced seizures, passive avoidance response, and elevated plus maze test. For the development of kindling PTZ was administered in a dose of 25 mg/kg, i.p. on every alternate day and RESV in all the three doses was administered daily. Seizure score was continuously monitored till the development of kindling and cognition tests were performed in the end of the study. The animals were sacrificed and levels of inflammatory biomarkers viz., IL-1β, interleukin-1 receptor antagonist (IL1-Ra), IL-6, and TNF-α were assessed in the hippocampus and cortex of the kindled animals. Results: RESV in all three doses increased the seizure threshold to hind limb extension in the ICES test. RESV in all the tested doses suppressed the development of kindling and reduced the levels of IL-1β, IL1-Ra, IL-6, and TNF-α in kindled mice. Conclusion: RESV suppressed the development of kindling in mice and decreased the levels of inflammatory biomarkers in their hippocampus. RESV modified brain inflammation during epileptogenesis and found to possess nootropic activity in the kindled mice.

Evaluation of anticonvulsant and nootropic effect of ondansetron in mice

The role of serotonin receptors have been implicated in various types of experimentally induced seizures. Ondansetron is a highly selective 5-hydroxytryptamine 3 (5-HT3) receptor antagonist used as antiemetic agent for chemotherapy-, and radiotherapy-induced nausea and vomiting. The present study was carried out to examine the effect of ondansetron on electroshock, pentylenetetrazole (PTZ)-induced seizures and cognitive functions in mice. Ondansetron was administered intraperitoneally (i.p.) at doses of 0.5, 1.0 and 2.0 mg/kg (single dose) to observe its effect on the increasing current electroshock seizure (ICES) test and PTZ-induced seizure test. In addition, a chronic study (21 days) was also performed to assess the effects of ondansetron on electroshock-induced convulsions and cognitive functions. The effect on cognition was assessed by elevated plus maze and passive avoidance paradigms. Phenytoin (25 mg/kg, i.p.) was used as a standard anticonvulsant drug and piracetam (200 mg/kg) was administered as a standard nootropic drug. The results were compared with an acute study, wherein it was found that the administration of ondansetron (1.0 and 2.0 mg/kg) significantly raised the seizure-threshold current as compared to control group in the ICES test. Similar results were observed after chronic administration of ondansetron. In PTZ test, ondansetron in all the three tested doses failed to show protective effect against PTZ-induced seizure test. Administration of ondansetron for 21 days significantly decreased the transfer latency (TL) and prolonged the step-down latency (SDL). The results of present study suggest the anticonvulsant and memory-enhancing effect of ondansetron in mice.

Efficacy and safety of canagliflozin in type 2 diabetes mellitus: systematic review of randomized controlled trials

Background: Currently available antihyperglycemic agents (AHAs), despite being effective, do not provide adequate glycemic control in some cases and are associated with side effects. A sodium glucose co-transporter 2 inhibitor, canagliflozin, is a newer AHA, which acts by decreasing the reabsorption of filtered glucose thereby elevating the urinary glucose excretion in diabetics. Areas covered: This systematic review was completed to assess the clinical effectiveness and safety of canagliflozin in T2DM. A literature search in PubMed, MEDLINE, Cochrane and ClinicalTrials.gov was conducted for randomized clinical trials of canagliflozin as an AHA by applying predetermined inclusion and exclusion criteria. Total 13 studies were included in the systematic review. The main outcomes assessed were change in HbA1c and fasting plasma glucose. Expert opinion: Canagliflozin monotherapy or combination therapy has the potential to decrease inadequately controlled hyperglycemia in T2DM. It acts by a novel insulin independent mechanism which complements the action of the existing AHA and improves glycemic control and decreases the body weight. Safety profile of canagliflozin indicates lower number of hypoglycemic episodes. Some manageable adverse events include genital mycotic infections, urinary tract infections, osmotic diuresis-related events etc. These findings affirm the utility of canagliflozin in T2DM; however, data on long-term safety and efficacy are needed.

Prevalence of depression in patients with type 2 diabetes attending an outpatient clinic in India

Background Clinical studies have suggested that depression is common among patients with type 2 diabetes (T2D). Depression is an important factor which affects the management and complications of diabetes. However, the available data regarding its prevalence in India are limited. Objectives To estimate the prevalence of depression in patients in India with T2D and to compare it with a non-diabetic group; and to determine the association of depression with glycaemic control and complications of diabetes in patients with T2D. Methods This case–control study was carried out over 5 months from May to September 2012 at a tertiary care hospital in India. Cases were patients with T2D and controls were individuals without diabetes. Depression was assessed using the Patient Health Questionnaire (PHQ)-9. The sociodemographic profile, duration of diabetes, presence of complications and other medical variables were also analysed. Results 260 subjects of Indian origin (162 men and 98 women; 130 with known T2D and 130 controls without T2D) were evaluated. The prevalence of depression in subjects with T2D was almost twice that in control subjects (46/130 (35.38%) vs 26/130 (20%); p=0.006). A statistically significant difference was found in the fasting blood glucose levels of subjects with depression and those without depression among the patients with T2D (145.70±53.92 vs 130.61±42.39; p=0.022), but depression was not found to be associated with any of the diabetic complications and glycaemic control. Conclusions Our findings demonstrate that there is a higher prevalence of depression in Indian patients with T2D, which is almost twice that in those without T2D. Since patients with T2D are at higher risk of developing depression, assessment of depression should be performed as part of the routine practice in India. Trial registration number CTRI/2012/06/002747.

A newer dimension to regulation of ethics committees in India

Abstract Clinical research is a pre-requisite part of the drug discovery and development process, with the main aim to ensure the safety and efficacy of any new drug. In today’s date, clinical trials are the backbone for bringing newer and better drugs to market. Although a set of established guidelines are available for governing the conduct of clinical trials in India, the ethics committees of this country are still struggling with basic issues viz, inadequate or no standard operating procedures (SOPs) and non-compliance with the Schedule Y recommendations. The ethics committee being the prime body with the responsibility of regulating clinical research, protecting and safeguarding the rights, safety and well-being of research participants, the institutions, hospitals, and pharmaceutical industries that focus on enhancing their research facilities tend to ignore the various aspects of ethics committees like composition and qualification of members forming the quorum, regular updates of ethics committees to be reported to the central authority, lack of administrative support and communication, inadequate remuneration offered to members serving to ethics committee boards, archival of records and regular auditing of the ethics committee. The central regulatory body of India CDSCO governing the conduct of clinical trial, in October 2012, under the guidance of Drugs Technical Advisory Board, laid down three major amendments in schedule Y. The present article discusses one of the new amendments laid down recently in schedule Y under rule 122 DD which states the requirements and guidelines needed for registration of ethics committees in India.

Assessment of Cognition and Quality of Life in Non-HodgkinâÂÂs Lymphoma Patients One Year Post-Treatment

Objectives: An increasing number of patients with cancer are offered chemotherapy given either alone or in combination with radiotherapy, surgery, or both as neo-adjuvant, concomitant, or adjuvant treatment. Cognitive dysfunction is a prevalent side effect of cancer treatments that may persist for years following treatment and has negative impact on quality of life. Thus, the present study was planned to investigate the prevalence of cognitive impairment, assess the quality of life (QOL) and determine the socioeconomic status in NHL patients one year post chemotherapy treatment. Methods: This was an observational study. All the prospective participants were screened on the basis of inclusion and exclusion criteria and the participants who met all the study inclusion criteria and had none of the exclusion criteria were enrolled in the study. Cognitive function was evaluated using Mini Mental State Examination (MMSE) or Hindi Mental State Examination (HMSE), socioeconomic status was determined by Kuppuswamy scale and quality of life (QoL) was assessed by EORTC QLQ. Results: A total of 90 subjects (45 cases and 45 controls) were enrolled in the study. The control group scored more on MMSE/HMSE scale than the Non-Hodgkin’s Lymphoma (NHL) patient group, suggesting difference in cognitive functioning between the groups (26.6 ± 2.4 vs. 27.8 ± 2.1, p=0.019), respectively. Socio-economic status did not have any impact on the prevalence of cognitive impairment in NHL patients; however, NHL was found to be more prevalent in upper-middle class. No significant difference was found between case and control for QoL. Conclusion: Cognitive dysfunction is a prevalent side effect of cancer treatment that may persist for a year following treatment. Further studies are needed to clarify the effect on quality of life.

Effects of agomelatine on pentylenetetrazole-induced kindling, kindling-associated oxidative stress, and behavioral despair in mice and modulation of its actions by luzindole and 1-(m-chlorophenyl) piperazine

In view of well-evidenced antiepileptic effects of melatonin and few reports of anticonvulsant action of agomelatine, the present study investigated whether agomelatine protects against pentylenetetrazole (PTZ)-induced kindling in mice and kindling-associated oxidative stress, depression, and impairment of spatial memory. In order to explore whether effects are mediated by melatonergic or serotonergic mechanisms, 1-(m-chlorophenyl) piperazine (mCPP), selective 5HT2c receptor agonist and luzindole, melatonergic receptor antagonist, were taken as pharmacological tools. In view of few hepatotoxic reports on agomelatine, the study evaluated effects on hepatic enzyme levels. Swiss strain albino mice were injected with PTZ (25mg/kg, i.p.) once every two days for 5weeks to induce kindling. The effects of agomelatine (10mg/kg, p.o.) alone and in combination with luzindole (2.5mg/kg, i.p.) or mCPP (7mg/kg, i.p.) on seizure severity during induction and % incidence of animals kindled at the end of 5weeks were recorded. Modified forced swim test was used for studying depression-like behavior while spontaneous alternation behavior was used for studying effects on spatial memory. Serum AST and ALT concentrations, cortical and hippocampal malondialdehyde, and reduced glutathione were measured. Agomelatine 10mg/kg, p.o. effectively delayed development of kindling, reduced seizure severity, and decreased % incidence. Luzindole reversed the protective effects of agomelatine while mCPP failed to show such a reversal, indicating melatonergic (and not serotonergic) mechanisms in the observed effects. Agomelatine also showed antioxidant effects that can partially contribute to its anticonvulsant action. In addition, it alleviated PTZ-kindling-associated behavioral despair and favorably modulated liver enzymes. Its effects on improvement of kindling-associated spatial memory could possibly be related to its effects on locomotor activity. Agomelatine, thus, could be explored as an adjunct to antiepileptic drugs for seizure control and for alleviating epilepsy-associated depression.