Intracerebroventricular administration of the (1→6)-ß-d-glucan (lasiodiplodan) in male rats prevents d-penicillamine-induced behavioral alterations and lipoperoxidation in the cortex.

CONTEXT: Lasiodiplodan, an exocellular (1→6)-ß-d-glucan of molecular weight >1.4 × 106 Da produced by MMPI strain of Lasiodiplodia theobromae (Pat.) Griffon & Maubl. (Brotyosphaeriaceae) is known to exhibit anti-proliferative activity on breast cancer cells (MCF-7), anticoagulant activity when sulfonylated, and reduction in transaminase activity when administered in rats. OBJECTIVE: The effect of intracerebroventricular (I.C.V) injection of lasiodiplodan on neurotoxicity and behavioural changes induced by d-penicillamine was investigated. MATERIALS AND METHODS: Twenty-four male Wistar rats were initially separated in groups of six and treated with 0.15 µmol/µL of NaCl (Groups Ct and d-Pen) and 0.01 µg/µL of lasiodiplodan (Groups Las and Las + d-Pen). After 15 min, they received 6 µmol/µL of NaCl (Groups Ct and Las) and 2 µmol/µL of d-penicillamine (Groups d-Pen and Las + d-Pen). The animal behavior was observed in an open-field test for 60 min. Twenty-four h later, the animals were sacrificed and histopathological analysis and Thiobarbituric acid reactive substances (TBARS) production measurements were performed. RESULTS: Lasiodiplodan prevented neurotoxicity induced by d-penicillamine significantly reducing the production of TBARS (308%; p < 0.05), and behavioural signs; convulsive and pre-convulsive. No histopathological alterations in the cerebral cortex were observed. DISCUSSION AND CONCLUSION: The reduction of TBARS production and convulsive episodes suggests that the protector effect provided by lasiodiplodan passes thought an antioxidant path, possibly interfering in a cascade of neurochemical events, triggering cell death and convulsive episodes. These results demonstrated that lasiodiplodan can be effective in treating neurotoxicity, and reducing damage triggered by convulsions in neuropathies related to GABAergic system.

Caffeine modifies blood glucose availability during prolonged low-intensity exercise in individuals with type-2 diabetes.

OBJECTIVE: The study investigated the effect of supplementation with maltodextrin (CHO) alone or associated to caffeine during exercise in T2DM subjects. METHODS: Pilot study, using eight subjects with T2DM, aged 55±10 years, received CHO (1 g/kg) or caffeine (1.5 mg/kg) alone or associated before exercise protocol. The exercise was executed at 40% heart rate (HR) reserve for 40 min, with 10-min recovery. Blood pressure (BP) and perceived exertion scale (Borg) were checked every 2 min. Blood glucose (BG) was checked every 10 min. For statistical analysis, ANOVA test was used and the value was considered statistically significant at p <0.05. RESULTS: The results showed that BP and HR did not change significantly among all treatments. Caffeine promoted a significant reduction in BG of 75 mg/dL (65%, p <0.05) during 40 min of exercise protocol compared to all groups. CONCLUSION: Supplementation with 1.5 mg/kg of caffeine reduces BG concentration during prolonged exercise in T2DM patients.

OBJECTIVO: Investigar los efectos de la suplementación con maltodextrina (CHO) sólo o combinado con cafeína durante el ejercicio en sujetos con diabetes tipo 2 . MÉTODOS: Estudio piloto que incluyó ocho sujetos con DM2, de 55±10 años, el CHO (1g/kg) o cafeína (1.5 mg/kg) sólo o combinado antes del protocolo de ejercicio. El ejercicio se realizó a 40% de la frecuencia cardiaca (FC). Reserva del corazón durante 40 min con 10 min de recuperación. La presión arterial (PA) y la escala de esfuerzo (Borg) fueron revisadas cada 2 min. La glucosa en sangre (GS) se comprobó cada 10 min. El análisis estadístico se realizó mediante ANOVA, y consideró significación estadística un valor de p <0.05. RESULTADOS: Los resultados muestran que PA, FC y Borg no difirió significativamente entre los tratamientos. La cafeína promueve una reducción significativa en los niveles de glucosa en la sangre de 75 mg/dL (65%, p <0.05), durante un protocolo de ejercicio de 40 min en comparación con todos los grupos. CONCLUSIONES: Suplementación con 1.5 mg/kg de cafeína redujo significativamente los niveles de GS durante el protocolo de ejercicio en pacientes con DM2 .

Acute hypothalamic administration of L-arginine increases feed intake in rats / Administração hipotalâmica aguda de L-arginina aumenta a ingestão alimentar em ratos

Objective: This study investigated the chronic (oral) and acute (hypothalamic infusion) effects of L-arginine supplementation on feed intake, body composition, and behavioral changes in rats. Methods: Twenty rats were divided into two groups treated orally for 60 days; one group received L-arginine (1 g/kg body weight) and one group received saline (1 mL/NaCl 0.9%). Daily consumption of water and food were evaluated, and weight monitored. After the oral treatment, the rats underwent stereotactic biopsy and a group was injected with 2 µL of L-arginine (0.5 mM) and another received an injection of saline (0.9% NaCl), in the hypothalamic route, through micro infusion. Immediately after micro infusion, the animal behavior was evaluated through tests in the open field. Food and water consumption were evaluated at 12 and 24 hours after the micro infusion. Daily water consumption and weight gain evolution were evaluated. At the end of treatments, rats were euthanized and blood was collected for glucose, glycerol, and cholesterol evaluation, and histological analysis of vital organs. Results: Oral supplementation with L-arginine increased water intake (11%, p<0.05) and promoted weight gain (3%, p<0.05). However, hypothalamic infusion promoted a significant increase in chow intake (30%, p<0.05) after 24 hours of L-arginine administration. Conclusion: Chronic oral treatment with L-arginine was not effective on appetite modulation; however, an effect was observed when L-arginine was administered directly into the hypothalamus, suggesting a central regulation on appetite through nNOS sensitization. Chronic use of L-arginine did not cause substantial changes in anthropometric, biochemical, behavioral, or histological variables. .

Objetivo: Este estudo investigou os efeitos da suplementação crônica (oral) e aguda (infusão no hipotálamo) com L-arginina sobre a saciedade, composição corporal e mudanças comportamentais em ratos. Métodos: Vinte ratos foram divididos em dois grupos e tratados por via oral durante 60 dias; um grupo recebeu uma dose de L-arginina (1 g/kg de peso corporal), outro grupo recebeu uma dose de solução salina (1 mL/NaCl 0.9%). O consumo diário de água e comida e a evolução do ganho de peso foram avaliados. Após o tratamento por via oral, os ratos foram submetidos à estereotaxia: um grupo recebeu uma injeção com 2 µl de L-Arginina (0.5 mM) e outro recebeu uma injeção de solução salina (NaCl 0,9%), no hipotálamo, através de microinfusão. Imediatamente após a microinfusão, foi avaliado o comportamento dos animais através do teste em campo aberto. O consumo de água e de comida foi avaliado nas 12 e 24 horas seguintes à microinfusão. No final dos tratamentos, os ratos foram eutanasiados para coleta de amostras para dosagem de glicose, glicerol e colesterol, além da análise histológica dos órgãos. Resultados: A suplementação oral com L-arginina promoveu aumento do consumo de água (11%, p<0,05) e ganho de peso (3%, p<0,05). Além disso, a infusão hipotalâmica promoveu um aumento significativo do consumo alimentar (30%, p<0,05) após 24 horas da administração de L-arginina. Conclusão: O tratamento oral crônico com L-arginina não obteve efeitos na modulação do apetite. No entanto, ocorreu aumento da ingestão de alimento quando a L-arginina foi administrada diretamente no hipotálamo, sugerindo que exista uma estimulação do apetite através da sensibilização da nNOS nessa região. O uso crônico de L-arginina não causou mudanças substanciais nos dados antropométricos, bioquímicos, comportamentais ou histológicos. .