Juliana Sartori Bonini

GM1 ganglioside attenuates convulsions and thiobarbituric acid reactive substances production induced by the intrastriatal injection of methylmalonic acid

The effects of the administration of monosialoganglioside (GM1) on methylmalonic acid (MMA)-induced convulsions, production of thiobarbituric acid reactive substances (TBARS) and on the striatal content of ascorbic acid and total non-protein thiol (SH) groups were evaluated in adult male rats. Animals received two intraperitoneal injections of GM1 (50 mg/kg) or saline (0.85% NaCl) spaced 24h apart. Thirty minutes after the second GM1 or saline injection, L-MMA (6 micromol) or NaCl (9 micromol) was injected into the right striatum and the animals were observed for the appearance of convulsions for 15 min. The animals were sacrificed and their striatal content of ascorbic acid, SH groups and TBARS was measured. The effect of GM1 on MMA-induced TBARS production in striatal homogenates was also evaluated in vitro.MMA injection caused convulsions (Sal-MMA: 9.8+/-1.4 episodes, which lasted 271+/-48 s) and increased the striatal content of TBARS (Sal-MMA: 149.0+/-11.5 nmol MDA/g tissue), but did not alter total striatal SH or ascorbic acid contents. GM1 pretreatment decreased MMA-induced convulsions (GM1-MMA: 6.3+/-2.0 episodes, which lasted 115.1+/-42.2s) and TBARS increase (GM1-MMA: 102.4+/-19.5 nmol MDA/g tissue). GM1 pretreatment increased ascorbic acid content of the striata (saline-pretreated: 1514+/-75.9; GM1-pretreated: 1878.6+/-102.8 microg ascorbic acid/mg tissue). MMA increased TBARS production in vitro, and GM1 had no effect on such MMA-induced effect. This study provides evidence that GM1 increases striatal ascorbic acid content and decreases MMA-induced neurotoxicity assessed by behavioral and neurochemical parameters.

Ammonia potentiates methylmalonic acid-induced convulsions and TBARS production

Hyperammonemia is a common finding in children with methylmalonic acidemia, an inherited metabolic disease characterized by mental retardation, convulsions, and accumulation of methylmalonic acid (MMA). Although it has been suggested that MMA induces convulsions through succinate dehydrogenase (SDH) inhibition, very little is known about the contribution of hyperammonemia to the development of convulsions in these patients. In the present study we investigated the effects of ammonium ions on the convulsant action of MMA, MMA-induced inhibition of striatal succinate dehydrogenase, and the striatal content of thiobarbituric acid-reactive substances (TBARS). Adult rats were injected with ammonium acetate (1.5 mmol/kg, sc) or sodium acetate (1.5 mmol/kg, sc), followed 5 min later by buffered MMA (3 micromol/microl) or NaCl (4.5 micromol/microl) injected into the striatum. The animals were observed in an open field for the appearance of convulsive episodes. After 30 min of behavioral evaluation, the animals were sacrificed and had their striatal TBARS content measured. Ammonium acetate pretreatment caused no behavioral effects per se, but potentiated MMA-induced convulsions and increased basal TBARS content and MMA-induced TBARS production in the striatum. Ammonium chloride had no effect on basal succinate dehydrogenase activity and did not alter MMA-induced inhibition of SDH in vitro. These results suggest that ammonia potentiates MMA-induced behavioral effects through a mechanism that does not involve further succinate dehydrogenase inhibition, but may involve facilitation of MMA-induced oxidative damage and provide evidence that ammonia and MMA may have mutually additive toxicity.

Monosialoganglioside Increases Catalase Activity in Cerebral Cortex of Rats

Monosialoganglioside (GM1) is a neuroprotective agent that has been reported to scavenge free radicals generated during reperfusion and to protect receptors and enzymes from oxidative damage. However, only a few studies have attempted to investigate the effects of GM1 on enzymatic antioxidant defenses of the brain. In the present study, we evaluate the effects of the systemic administration of GM1 on the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), and on spontaneous chemiluminescence and total radical-trapping potential (TRAP) in cerebral cortex of rats ex vivo. The effects of GM1 on CAT activity and spontaneous chemiluminescence in vitro were also determined. Animals received two injections of GM1 (50 mg/kg, i.p.) or saline (0.85% NaCl, i.p.) spaced 24 h apart. Thirty minutes after the second injection the animals were sacrificed and enzyme activities and spontaneous chemiluminescence and TRAP were measured in cell-free homogenates. GM1 administration reduced spontaneous chemiluminescence and increased catalase activity ex vivo, but had no effect on TRAP, SOD or GSH-Px activities. GM1, at high concentrations, reduced CAT activity in vitro. We suggest that the antioxidant activity of GM1 ganglioside in the cerebral cortex may be due to an increased catalase activity.

Nutritional evaluation of geriatric patients with Alzheimer’s disease in Southern Brazil: case-control study

INTRODUCTION elderlys malnutrition is linked, among other factors, to chronic-degenerative diseases, requiring an improvement in the clinical evaluation of nutritional status of this population. Studies have tried to find out new tools to assess aged-people nutritional status. One of most used scales to investigate nutritional status on geriatric patients is the Mini Nutritional Assessment (MNA). OBJECTIVE the present study aims to evaluate nutritional status of Alzheimers disease (AD) patients, by comparison with a control group, via Mini Nutritional Assessment. METHODS a cross-sectional study, which includes 35 alzheimers old-people and 43 control old-people, was performed evaluating nutritional status with MNA. RESULTS total score of MNA in the alzheimer group shows that 71.42% were in malnutrition risk, 14.28% were malnourished and 14.25% presented normal nutritional status. In addition, in the control group 79.06% of patients (n = 34) were classified as having normal nutritional status and 20.93% (n = 9), as being at risk of malnutrition. CONCLUSION results reinforce the purpose that MNA can be used as a proper instrument to evaluate nutritional status in elderly, mainly in AD, because measuring risk and nutritional status of this population is indispensable.

Ethyl acetate fraction of Cymbopogon citratus as a potential source of antioxidant compounds

This study aimed to characterize different extracts/fractions obtained from Cymbopogon citratus according to their chemical composition and antioxidant properties. Plant leaves were submitted to extractions with different solvents, and the antioxidant capability of each fraction was analyzed using different methods (E1–E4). The ethyl acetate fraction from extraction procedure 1 (E1) presented a high polyphenolic content and antioxidant capability. Therefore, in E2, the pH of the aqueous phases was modified to fractionate the compounds in the ethyl acetate extractions. Interestingly, the fraction obtained at pH 4 presented a higher antioxidant activity than AcOEt F1. Furthermore, it was verified that the essential oil removal improved the extraction of polyphenols in ethyl acetate fractions. The antioxidant activity of these fractions was comparable to ascorbic acid, and could also inhibit TBARS production in phospholipids comparatively to vitamin E. Such fraction will be further explored to isolate the active chemicals, and to evaluate its toxicity and antioxidant actions in vivo.

Potential biomarkers for alzheimer’s disease screened in a small Brazilian population

Submit Manuscript | http://medcraveonline.com Abbreviations: AD: Alzheimer’s Disease; CDR: Clinical Dementia Rating; MNA: Mini Nutritional Assessment; HDL: High Density Lipoprotein; LDL: Low Density Lipoprotein Levels; Aβ: Accumulation of Beta-Amyloid; NINCDS-ADRDA: National Institute of Neurologic and Communicative Disorders and Stroke and the Alzheimer Disease and Related Disorders Association; MMSE: Mini-Mental State Exam; ALT: Alanine Transaminase; AST: Aspartate Transaminase; CBC: Complete Blood Count

Evaluation of curcumin toxicity in rats through biochemical and hematological parameters

Curcumin is a natural compound known for hepatic and nephroprotective actions, however, there is little research related to its possible side effects. The research aimed to study hematological, biochemical parameters and histopathology of hepatic and renal tissues to evaluate the effects of curcumin toxicity in male rats. A group of Wistar male rats (n = 10) was orally treated for five days with 100 mg/kg of curcumin diluted in vegetable oil, and the other group (n=10) was treated with vegetable oil (control). Statistical difference was observed in the levels of creatinine, hematocrit, hemoglobin, and red blood cells count between the control and curcumin treated group. However, despite these differences, the values observed were within the normal ranges for of Wistar male rats. Histopathological alterations were not observed. Therefore, our results show that curcumin is relatively non-toxic and, because of its demonstrated pharmacological effects, it can be developed as a promising candidate drug. Key words: Curcumin, toxicity, side effects.