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The number of people with dementia worldwide is estimated at 50 million by 2018 and continues to rise mainly due to increasing aging and population growth. Clinical impact of current interventions remains modest and all efforts aimed at the identification of new therapeutic approaches are therefore critical. Previously, we showed that JM-20, a dihydropyridine-benzodiazepine hybrid molecule, protected memory processes against scopolamine-induced cholinergic dysfunction. In order to gain further insight into the therapeutic potential of JM-20 on cognitive decline and Alzheimer's disease (AD) pathology, here we evaluated its neuroprotective effects after chronic aluminum chloride (AlCl3) administration to rats and assessed possible alterations in several types of episodic memory and associated pathological mechanisms. Oral administration of aluminum to rodents recapitulates several neuropathological alterations and cognitive impairment, being considered a convenient tool for testing the efficacy of new therapies for dementia. We used behavioral tasks to test spatial, emotional- associative and novel object recognition memory, as well as molecular, enzymatic and histological assays to evaluate selected biochemical parameters. Our study revealed that JM-20 prevented memory decline alongside the inhibition of AlCl3 -induced oxidative stress, increased AChE activity, TNF-α and pro-apoptotic proteins (like Bax, caspase-3, and 8) levels. JM-20 also protected against neuronal damage in the hippocampus and prefrontal cortex. Our findings expanded our understanding of the ability of JM-20 to preserve memory in rats under neurotoxic conditions and confirm its potential capacity to counteract cognitive impairment and etiological factors of AD by breaking the progression of key steps associated with neurodegeneration.

Context: Momordica charantia (Cucurbitaceae) is extensively distributed in tropical areas, and it is traditionally used as antidiabetic. Nevertheless, few studies supporting the metabolic effects of its foliage extracts have been reported elsewhere. Aims: To evaluate the effects of M. charantia foliage extract (MCh) on blood glucose and lipids levels in animal models of hyperglycemia. The anti-inflammatory and antioxidant properties together with the acute toxicity and genotoxic effects were also assessed. Methods: An MCh powder was obtained by spray-drying techniques. The anti-hyperglycemic and hypolipidemic effects of MCh were evaluated in the glucose tolerance test and the alloxan-induced diabetes, respectively. The in vitro and ex vivo MCh antioxidant effects were assessed against the 2,2´-azinobis3-ethylbenzothiazoline-6-sulfonic acid (ABTS), peroxyl, and superoxide anion radicals. The MCh anti-inflammatory effects were also assessed together with its toxicological profile by means of the Acute Toxic Class Method, and the chromosome aberration assay. Results: MCh administered orally diminished the glucose and lipids levels in normoglycemic healthy rats and alloxan-induced hyperglycemic mice. Strong in vitro free radical scavenging effects was demonstrated by MCh against ABTS, peroxyl, and superoxide anion radicals. The extract also improved the free radical scavenging ability of diabetic mice serum. Moreover, MCh reduced the weight of cotton-induced granulomas in mice, the exudate volume, and its leukocyte counts in carrageenan-induced pleurisy in rats. Very low MCh toxicity was also verified. Conclusions: The hypoglycemic, hypolipidemic, anti-inflammatory, and antioxidant activities here observed make the spray-drayed powder from M. charantia foliage extract an interesting alternative for the correction of diabetes and its complications.

Alzheimer's disease (AD) is a neurodegenerative disease that worsens with aging. Today, there is a worldwide effort to find new drugs that could delay the onset, slow the progression, or improve symptoms of AD. Oral administration of aluminum to rodents recapitulates some pathological alterations observed in AD, being considered a convenient tool for modeling and testing the efficacy of new therapeutics. Our previous studies have shown that JM-20, a dihydropyridine and benzodiazepine hybrid molecule protected memory in an environment with cholinergic dysfunction, high oxidative stress, hyperactivation of acetylcholinesterase (AChE) enzyme, and mitochondrial damage produced by scopolamine. In order to gain further insight into the effects on JM-20 on AD pathology, we evaluated the protective effects of JM-20 after chronic AlCl3 administration to rats, and assessed several types of episodic memory alterations and associated-pathological mechanisms, including mitochondrial dysfunction, AChE hyperactivity, inflammation, and apoptosis-related proteins. We used behavioral tasks to test spatial, working an emotional- associative memory, as well as molecular, enzymatic and histological assays to evaluate selected biochemical parameters. Our study showed that JM-20 prevented memory decline alongside with the inhibition of aluminum-induced alterations of oxidative parameters, and increase of AChE activity and of tumor necrosis factor alpha (TNF-α) levels. JM-20 also preserved anti-apoptotic proteins and protected against axonal and neuronal damaged in the hippocampus and prefrontal cortex. Altogether, our findings expanded our understanding of the ability of JM-20 to preserve essential types of memory in rats under neurotoxic conditions, and suggest its potential capacity to counteract etiological factors of AD by breaking the progression of key neurodegeneration-associated steps in a rat model of the disease.

Objective: Scopolamine (SCO) administration to rats induces molecular features of AD and other dementias, including impaired cognition, increased oxidative stress, and imbalanced cholinergic transmission. Although mitochondrial dysfunction is involved in different types of dementias, its role in cognitive impairment induced by SCO has not been well elucidated. The aim of this work was to evaluate the in vivo effect of SCO on different brain mitochondrial parameters in rats to explore its neurotoxic mechanisms of action.Methods: Saline (Control) or SCO (1 mg/kg) was administered intraperitoneally 30 min prior to neurobehavioral and biochemical evaluations. Novel object recognition and Y-maze paradigms were used to evaluate the impact on memory, while redox profiles in different brain regions and the acetylcholinesterase (AChE) activity of the whole brain were assessed to elucidate the amnesic mechanism of SCO. Finally, the effects of SCO on brain mitochondria were evaluated both ex vivo and in vitro, the latter to determine whether SCO could directly interfere with mitochondrial function.Results: SCO administration induced memory deficit, increased oxidative stress, and increased AChE activities in the hippocampus and prefrontal cortex. Isolated brain mitochondria from rats administered with SCO were more vulnerable to mitochondrial swelling, membrane potential dissipation, H2O2 generation and calcium efflux, all likely resulting from oxidative damage. The in vitro mitochondrial assays suggest that SCO did not affect the organelle function directly.Conclusion: In conclusion, the present results indicate that SCO induced cognitive dysfunction and oxidative stress may involve brain mitochondrial impairment, an important target for new neuroprotective compounds against AD and other dementias.

Objective: JM-20, a novel hybrid synthetic molecule, has been reported to have antioxidant, mitoprotective, anti-excitotoxic, anti-apoptotic and anti-inflammatory properties. However, the neuroprotective effect of JM-20 against memory impairment in preclinical AD-like models has not been analyzed. The aim of this study was to evaluate the potential neuroprotection of JM-20 that preserves essential memory process from cholinergic dysfunction and other molecular damages. Methods: The effects of JM-20 on scopolamine (1 mg/kg)-induced cognitive disorders were studied. Male Wistar rats (220-230 g) were treated with JM-20 and/or scopolamine, and behavioral tasks were performed. The AChE activity, superoxide dismutase activity, catalase activity, MDA and T-SH level on brain tissue were determined by spectrophotometric methods. Mitochondrial functionality parameters were measured after behavioral tests. Histological analyses on hippocampus and prefrontal cortex were processed with hematoxylin and eosin, and neuronal and axonal damage were determined. Results: The behavioral, biochemical and histopathological studies revealed that oral pre-treatment with JM-20 (8 mg/kg) significantly attenuated the scopolamine-induced memory deficits, mitochondrial malfunction, oxidative stress, and prevented AChE hyperactivity probably due to specific inhibition of AChE enzyme. It was also observed marked histological protection on hippocampal and prefrontal-cortex regions. Conclusions: The multimodal action of this molecule could mediate the memory protection here observed and suggest that it may modulate different pathological aspects of memory de?cits associated with AD in humans.

The aim of the present work was to investigate the anti-inflammatory and antinociceptive effects of methanolic extract from D. obtusata using classic models in mice (croton oil-induced ear edema and acetic acid-induced writhing) and a phospholipase A2 activity test. Qualitative analysis of the chemical composition of seaweed was also determined by extraction with solvents of increasing polarity and precipitation and color tests. Results of qualitative chemical study showed the presence of lactonic and phenolic compounds, reduced carbohydrates, other sugars, flavonoids, fatty compounds, triterpenes and steroids. The extract inhibited mouse ear edema in a dose-dependent manner with an efficacy higher than 90% and a mean effective dose of 4.87µg/ear, while intraperitoneal administration presented a moderate activity. The extract did not inhibit phospholipase A2 activity. In the writhing test, the intraperitoneal administration of the extract showed a strong antinociceptive activity (80.2%), while the oral route showed a lower efficacy. In conclusion, this study demonstrated the anti-inflammatory and antinociceptive effects of methanol extract of D. obtusata in experimental models, suggesting its therapeutic potential in the treatment of peripheral painful and/or inflammatory pathologies.O objetivo do presente trabalho foi investigar os efeitos antiinflamatórios e antinociceptivos de um extrato metanólico de D. obtusata, utilizando modelos clássicos em ratos (teste do edema de orelha induzido por óleo de cróton e teste de contorções induzidas por ácido acético) e um teste de atividade de fosfolipase A2. A análise qualitativa da composição química das algas foi também determinada através de extração com solventes de polaridade crescente e testes de precipitação e cor. Os resultados do estudo de química qualitativa mostraram a presença de compostos lactônicos e fenólicos, hidratos de carbono reduzidos e outros açúcares, flavonoides, compostos graxos, triterpenos e esteroides. O extrato inibiu o edema de orelha dos ratos de um modo dependente da dose com eficácia superior a 90% e dose média efetiva de 4.87µg/orelha, enquanto a administração intraperitoneal apresentou atividade moderada. O extrato não inibiu a atividade da fosfolipase A2. No teste de contorção, a administração intraperitoneal do extrato mostrou forte atividade antinociceptiva (80,2%), enquanto a administração oral mostrou menor eficácia. Em conclusão, este estudo demonstrou os efeitos antiinflamatórios e antinociceptivos do extrato metanólico de D. obtusata em modelos experimentais, sugerindo seu potencial terapêutico no tratamento de patologias dolorosas periféricas e/ou inflamatórias.

The effects of an extract from the marine plant Thalassia testudinum on rat liver cytochrome P450s were investigated. Male Wistar rats were administered for 10 days with 20, 200 or 400 mg/kg oral doses of the extract. The activities of CYP1A1/A2, CYP2B1/B2, CYP2E1 and CYP3A were evaluated. CYP1A1 activity and protein content increased after 200 mg/kg of the extract but mRNA levels remain unchanged. The activity of other CYP isoforms did not change. The S9 fraction derived from the livers of the rats treated with the extract was used to evaluate the effects of this product on the mutagenic activation of benzo[a]pyrene. The number of Salmonella mutant colonies induced by benzo[a]pyrene in the presence of S9 obtained from animals treated with 200 and 400 mg/kg of the extract were respectively 1.8 and 2.3-fold higher than controls, while it was reduced at the 20 mg/kg dose. This strongly support the idea that the extract modulated the liver enzymes which transform benzo[a]pyrene into mutagenic metabolites. Another set of male rats were treated for 10 days with the same doses. Sixteen hours later, rats received oral doses of theophylline (10 mg/kg), blood samples were extracted from each animal at 0, 0.25, 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 h after administration and plasma theophylline concentration was measured. Pre-treatment with the extract increased theophylline clearance. Our results suggested that the extract modify CYP1A in vivo activity and metabolism-based pharmacokinetic interactions between the extract and CYP1A substrates may occur in vivo.