Avaliação da estabilidade e atividade antioxidante de formulações com o extrato de Mangifera indica L / Evaluation of the stability and antioxidant activity of formulations with Mangifera indica L. extract

A elevada produção global de Mangifera indica gera uma considerável quantidade de resíduos, como cascas e sementes que são frequentemente descartados. O aproveitamento desses subprodutos promove uma abordagem mais sustentável, reduzindo impactos ambientais e abrindo novas perspectivas na área fitocosmética. A casca apresenta metabólitos secundários conhecidos principalmente por suas propriedades antioxidantes, destacando-se os compostos fenólicos. Esses antioxidantes são capazes de retardar a velocidade de oxidação promovida por radicais livres formados por fatores externos ou fisiopatológicos. Assim, antioxidantes naturais extraídos a partir de espécie vegetal estão sendo cada vez mais estudados para aplicação na indústria cosmética e farmacêutica. O potencial fitocosmético do extrato glicólico da casca de M. indica L. var. Tommy Atkins em três bases galênicas (gel de Carbopol®, gel-creme e gel de Estagel®) foi avaliado por meio dos ensaios de atividade antioxidante, pelo método do radical DPPH, e estudos de estabilidade. As formulações com o extrato apresentaram-se estáveis e compatíveis para o uso tópico, pois não foram verificados sinais de instabilidade como alteração das características organolépticas e do pH. Em relação à atividade antioxidante, formulações com o extrato apresentaram potencial antioxidante, porém a formulação com Carbopol® e gel-creme apresentaram melhor desempenho em relação ao Estagel®. Após 30 dias de estabilidade preliminar em diferentes condições de temperatura (40,0 ± 2<0°C, 20,0 ± 5,0°C, 5,0 ± 2,0°C) houve redução de atividade antioxidante somente no gel de Carbopol® armazenado sob elevada temperatura, indicando a melhor forma de armazenamento. Diante disso, os resultados sugerem a promissora incorporação de M. indica L. var. Tommy Atkins em bases cosméticas.

The high global production of Mangifera indica generates a considerable amount of waste, such as peels and seeds that are often discarded. The use of these by-products promotes a more sustainable approach, reducing environmental impacts and opening new perspectives in the phytocosmetics area. The peel presents secondary metabolites known mainly for their antioxidant properties, highlighting phenolic compounds. These antioxidants are capable of slowing down the rate of oxidation promoted by free radicals formed by external or pathophysiological factors. Thus, natural antioxidants extracted from plant species are increasingly being studied for application in the cosmetic and pharmaceutical industry. The phytocosmetic potential of the glycolic extract from the peel of M. indica L. var. Tommy Atkins in three galenic bases (Carbopol® gel, cream gel and Estagel® gel) was evaluated through antioxidant activity tests, the DPPH radical scavenging method, and stability studies. The formulations with the extract were stable and compatible for topical use, as there were no signs of instability such as changes in organoleptic characteristics and pH. Regarding antioxidant activity, formulations with the extract showed antioxidant potential, however the formulation with Carbopol® and gel-cream showed better performance compared to Estagel®. After 30 days of preliminary stability in different temperature conditions (40.0 ± 2<0°C, 20.0 ± 5.0°C, 5.0 ± 2.0°C) there was a reduction in antioxidant activity only in the gel of Carbopol® stored at high temperature, indicating the best form of storage. Therefore, the results suggest the promising incorporation of M. indica L. var. Tommy Atkins in cosmetic foundations.

Decreased neuron loss and memory dysfunction in pilocarpine-treated rats pre-exposed to hypoxia.

Preconditioning can induce a cascade of cellular events leading to neuroprotection against subsequent brain insults. In this study, we investigated the chronic effects of hypoxic preconditioning on spontaneous recurrent seizures (SRS), neuronal death, and spatial memory performance in rats subjected to pilocarpine (Pilo)-induced status epilepticus (SE). Rats underwent a short hypoxic episode (7% O2+93% N2; 30min on two consecutive days) preceding a 4-h SE (HSE group). Control groups were rats submitted to SE only (SE), rats subjected to hypoxia only (H) or normoxia-saline (C). Animals were monitored for the occurrence of SRS, and spatial memory performance was evaluated in the radial-arm maze. Hippocampal sections were analyzed for cell death and mossy fiber sprouting at 1 or 60days after SE. Compared to SE group, HSE had increased SE latency, reduced number of rats with SRS, reduced mossy fiber sprouting at 60days, and reduced cell death in the hilus and the CA3 region 1 and 60days after SE. Additionally, HSE rats had better spatial memory performance than SE rats. Our findings indicated that short hypoxic preconditioning preceding SE promotes long-lasting protective effects on neuron survival and spatial memory.

Effects of nitric oxide-related compounds in the acute ketamine animal model of schizophrenia.

BACKGROUND: Better treatments for schizophrenia are urgently needed. The therapeutic use of the nitric oxide (NO)-donor sodium nitroprusside (SNP) in patients with schizophrenia has shown promising results. The role of NO in schizophrenia is still unclear, and NO modulation is unexplored in ketamine (KET) animal models to date. In the present study, we compared the behavioral effects of pre- and post-treatment with SNP, glyceryl trinitrate (GTN), and methylene blue (MB) in the acute KET animal model of schizophrenia. The present study was designed to test whether acute SNP, GTN, and MB treatment taken after (therapeutic effect) or before (preventive effect) a single KET injection would influence the behavior of rats in the sucrose preference test, object recognition task and open field. RESULTS: The results showed that KET induced cognitive deficits and hyperlocomotion. Long- term memory improvement was seen with the therapeutic GTN and SNP treatment, but not with the preventive one. MB pretreatment resulted in long-term memory recovery. GTN pre-, but not post-treatment, tended to increase vertical and horizontal activity in the KET model. Therapeutic and preventive SNP treatment consistently decreased KET-induced hyperlocomotion. CONCLUSION: NO donors - especially SNP - are promising new pharmacological candidates in the treatment of schizophrenia. In addition, we showed that the potential impact of NO-related compounds on KET-induced behavioral changes may depend on the temporal window of drug administration.

Animal models of epilepsy: use and limitations.

Epilepsy is a chronic neurological condition characterized by recurrent seizures that affects millions of people worldwide. Comprehension of the complex mechanisms underlying epileptogenesis and seizure generation in temporal lobe epilepsy and other forms of epilepsy cannot be fully acquired in clinical studies with humans. As a result, the use of appropriate animal models is essential. Some of these models replicate the natural history of symptomatic focal epilepsy with an initial epileptogenic insult, which is followed by an apparent latent period and by a subsequent period of chronic spontaneous seizures. Seizures are a combination of electrical and behavioral events that are able to induce chemical, molecular, and anatomic alterations. In this review, we summarize the most frequently used models of chronic epilepsy and models of acute seizures induced by chemoconvulsants, traumatic brain injury, and electrical or sound stimuli. Genetic models of absence seizures and models of seizures and status epilepticus in the immature brain were also examined. Major uses and limitations were highlighted, and neuropathological, behavioral, and neurophysiological similarities and differences between the model and the human equivalent were considered. The quest for seizure mechanisms can provide insights into overall brain functions and consciousness, and animal models of epilepsy will continue to promote the progress of both epilepsy and neurophysiology research.