The effect of subchronic supplementation with folic acid on homocysteine induced seizures

Influence of folic acid on the CNS is still unclear. Folate has a neuroprotective effect, while on the other hand excess folate can exacerbate seizures in epileptics. The aim of the present study was to examine the effect of subchronic administration of folic acid on behavioural and electroencephalographic (EEG) characteristics of DL homocysteine thiolactone induced seizures in adult rats. The activity of Na+/K+-ATPase and Mg2+-ATPase in different brain regions was investigated. Adult male Wistar rats were divided into groups: 1. Controls (C, 0.9% NaCl); 2. DL homocysteine-thiolactone 8.0 mmol/kg (H); 3. Subchronic supplementation with folic acid 5 mg/kg for 7 days (F) and 4. Subchronic supplementation with F + single dose of H (FH). Seizure behaviour was assessed by incidence, latency, number and intensity of seizure episodes. Seizure severity was described by a descriptive scale with grades 0–4. For EEG recordings, three gold-plated recording electrodes were implanted into the skull. Subchronic supplementation with folic acid did not affect seizure incidence, median number of seizure episodes and severity in FH, comparison with H (p > 0.05). The majority of seizure episodes in all groups were of grade 2. There were no significant differences in lethal outcomes at 24 h upon H injection in the FH vs. H group. The activity of Na+/K+-ATPase and Mg2+-ATPase was significantly increased in almost all examined structures in the FH vs. H group. Subchronic folic acid administration did not exacerbate H induced seizures and completely recovered the activity of ATPases

Convulsive properties of D,L homocysteine and D,L homocysteine thiolactone in adult rats

Introduction: Hyperhomocysteinemia is related to epileptogenesis and suboptimal control of seizures in the patients with epilepsy. Available data suggest that homocysteine can be harmful to human cells because of its metabolic conversion to homocysteine thiolactone, a reactive thioester. The aim of the study was to investigate the convulsive properties of equimolar concentrations of D,L homocysteine and D,L homocysteine thiolactone in adult rats. Methods: Adult male Wistar rats were divided into following groups: 1. saline-treated (C, n=10), 2. D, L homocysteine 8 mM/kg, i.p. (H; n=8), and 3. D,L homocysteine-thiolactone (Ht; n=8). Seizure behavior was assessed by the incidence, latency, number and intensity of seizure episodes. Seizure severity was described by a descriptive scale with grades 0-4.Results: There were no behavioural signs of seizure activity in C group. The incidence of convulsions was lower in group H comparing to the Ht group but statistical significance was not attained. Latency to the first seizure onset was significantly higher in H comparing to the Ht group (p<0.01). Median number of seizure episodes and severity of seizure episodes per rat were significantly lower in H comparing to Ht group.Conclusion: Our findings suggest that D,L homocysteine thiolactone exerts stronger convulsive effect comparing to the equimolar concentration of D,L homocysteine

Cultivating Social Capital through Summer Employment Programs: Perspectives from Youth Participants

Significant socio-economic shifts, such as the emergence of the so-called ‘knowledge economy’ have transformed the transition from adolescence to adulthood, as youth are expected to garner a considerable amount of personal, cognitive, social, and educational skills in order to successfully enter adult society and prosper within the market economy. An additional determinant of the successful transition of youth into adult society is the availability of social capital through relationships and networks that can provide access to valuable resources and information and contribute to the development of a social identity. Employment programs are a mechanism for providing youth with workforce exposure and skill development in the absence of market opportunities. These programs are also a potential source of social capital, through the exposure to new environments and the development of relationships and networks that can provide resources that youth may not have access to through traditional means. Using a qualitative approach, we explored the perspectives of youth participants in a summer employment program in Southwestern Ontario, Canada. We propose that the opportunity to develop social capital is an under-recognized benefit of employment programs, and may be a particularly important aspect for disadvantaged youth.&nbsp

Exercise Decreases Susceptibility to Homocysteine Seizures: the Role of Oxidative Stress

The aim of the study was to examine the effects of chronic exercise training on seizures induced by homocysteine thiolactone (HCT) in adult rats. Rats were assigned to: sedentary control; exercise control; sedentary +HCT; exercise + HCT group. Animals in the exercise groups ran 30 min daily on a treadmill for 30 consecutive days (belt speed 20 m/min), while sedentary rats spent the same time on the treadmill (speed 0 m/min). On the 31st day, the HCT groups received HCT (8.0 mmol/kg), while the control groups received vehicle. Afterwards, convulsive behavior and EEG activity were registered. Lipid peroxidation, superoxide dismutase (SOD) and catalase (CAT) activity were ascertained in the rat hippocampus. No signs of seizures were registered in sedentary and exercise control rats. Seizure latency was increased, while number of seizure episodes and spike-and-wave discharges (SWD) in EEG were decreased in the exercise + HCT compared to the sedentary +HCT group. Seizure incidence, the severity thereof and duration of SWDs were not significantly different between these groups. Exercise partly prevented increase of lipid peroxidation and decrease of the SOD and CAT activity after HCT administration. These results indicate beneficial effects of exercise in model of HCT induced seizures in rats, what could be, at least in part, a consequence of improved antioxidant enzymes activity

The effect of subchronic supplementation with folic acid and L-arginine on homocysteine-induced seizures

The aim of the present study was to examine the effect of subchronic co-administration of folic acid (F) and L-arginine (A) on behavioural and electroencephalographic (EEG) characteristics of DL homocysteine thiolactone (H) induced seizures in adult rats. The activity of membrane ATPases in different brain regions were also investigated. Rats were treated with F, A, or vehicle for 15 days (regimen: F 5 mg/kg + A 500 mg/kg (F5A500); F 10 mg/kg + A 300 mg/kg (F10A300)). Seizures were elicited by convulsive dose of H (H, F5A500H, F10A300H) Subchronic supplementation with F and A did not affect seizure incidence, number of seizure episodes, and severity in F5A500H and F10A300H groups vs. H group. However, a tendency to increase latency and decrease the number of seizure episodes was noticed in the F10A300H group. EEG mean spectral power densities during ictal periods were significantly lower in F10A300H vs. H group. The activity of Na+/K+-ATPase and Mg2+-ATPase was significantly increased in almost all examined structures in rats treated with F and A. We can conclude that subchronic supplementation with folic acid and L-arginine has an antiepileptic effect in DL homocysteine thiolactone induced epilepsy.2nd European-Section Meeting of the International-Academy-of-Cardiovascular-Sciences (IACS), Oct 08-10, 2015, Belgrade, Serbi

The effects of acutely and subchronically applied DL-methionine on plasma oxidative stress markers and activity of acetylcholinesterase in rat cardiac tissue

© 2020 Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved. Background/Aim. Chronically induced hypermethioninemia leads to hyperhomocysteinemia which causes oxidative stress, atherogenesis, neurodegeneration and cancer. However, little is known about the acute and subchronic effects of DL-methionine (Met). The aim of study was to assess the effects of acutely and subchronically applied Met on oxidative stress parameters in rat plasma [enzymes: catalase (CAT), glutathione peroxidise (GPx), superoxide dismutase (SOD) and index of lipid peroxidation, malondialdehyde (MDA)], and acetylcholinesterase (AChE) activity in rat cardiac tissue. Methods. The enzymes activities, as well as MDA concentration were evaluated following acute (n = 8) and subchronic (n = 10) application of Met [i.p. 0.8 mmoL/kg body weight (b.w.) in a single dose in the acute overload or daily during three weeks in the subchronic overload]. The same was done in the control groups following application of physiological solution [i.p. 1 mL 0.9% NaCl (n = 8) in the acute overload and 0.1–0.2 mL 0.9% NaCl, daily during three weeks (n =10) in the subchronic overload]. Tested parameters were evaluated 60 minutes after application in acute experiments and after three weeks of treatment in subchronic experiments. Results. There were no difference in homocysteine values between the groups treated with Met for three weeks and the control group. Met administration significantly increased the activity of CAT and GPx after 1 h compared to the control group (p = 0.008 for both enzymes), whereas the activity of SOD and MDA concentrations were unchanged. Subchronically applied Met did not affect activity of antioxidant enzymes and MDA level. AChE activity did not show any change in rat cardiac tissue after 1 h, but it was significantly decreased after the subchronic treatment (p = 0.041). Conclusion. Results of present research indicate that Met differently affects estimated parameters during acute and subchronic application. In the acute treatment Met mobilizes the most part of antioxidant enzymes while during the subchronic treatment these changes seems to be lost. On the contrary, the acute Met overload was not sufficient to influence on the AChE activity, while longer duration of Met loading diminished function of the enzyme. These findings point out that methionine can interfere with antioxidant defense system and cholinergic control of the heart function