Vitamin E and Its Molecular Effects in Experimental Models of Neurodegenerative Diseases.

With the advancement of in vivo studies and clinical trials, the pathogenesis of neurodegenerative diseases has been better understood. However, gaps still need to be better elucidated, which justifies the publication of reviews that explore the mechanisms related to the development of these diseases. Studies show that vitamin E supplementation can protect neurons from the damage caused by oxidative stress, with a positive impact on the prevention and progression of neurodegenerative diseases. Thus, this review aims to summarize the scientific evidence of the effects of vitamin E supplementation on neuroprotection and on neurodegeneration markers in experimental models. A search for studies published between 2000 and 2023 was carried out in the PubMed, Web of Science, Virtual Health Library (BVS), and Embase databases, in which the effects of vitamin E in experimental models of neurodegeneration were investigated. A total of 5669 potentially eligible studies were identified. After excluding the duplicates, 5373 remained, of which 5253 were excluded after checking the titles, 90 articles after reading the abstracts, and 11 after fully reviewing the manuscripts, leaving 19 publications to be included in this review. Experiments with in vivo models of neurodegenerative diseases demonstrated that vitamin E supplementation significantly improved memory, cognition, learning, motor function, and brain markers associated with neuroregeneration and neuroprotection. Vitamin E supplementation reduced beta-amyloid (Aß) deposition and toxicity in experimental models of Alzheimer's disease. In addition, it decreased tau-protein hyperphosphorylation and increased superoxide dismutase and brain-derived neurotrophic factor (BDNF) levels in rodents, which seems to indicate the potential use of vitamin E in preventing and delaying the progress of degenerative lesions in the central nervous system.

Neuroprotective Potential of Seed Extracts: Review of In Vitro and In Vivo Studies.

INTRODUCTION: Neurodegenerative diseases are characterized by neuronal dysfunction and death. Studies suggest that some seed extracts have a neuroprotective effect. Considering the increased incidence of these diseases and the need for new effective therapies with fewer side effects, this review aimed to assess the evidence of the efficacy and safety of seed extracts in experimental models of neurodegeneration. MATERIAL AND METHOD: The search was carried out through studies published between 2000 and 2021 in Science Direct, PubMed, Scientific Electronic Library Online (SciELO), and Latin American Literature in Health Sciences (LILACS) databases, in which the effects of seed extracts in in vitro and in vivo experimental models of neurodegeneration were investigated. Based on the eligibility criteria, 47 studies were selected for this review. RESULTS: In the in vitro models, the neuroprotection of the seed extracts was a result of their antioxidant, anti-inflammatory, and anti-apoptotic properties. In the in vivo models, neuroprotection resulted from the antioxidant and anti-inflammatory properties, a decrease in motor deficits, an improvement in learning and memory, as well as the increased release of neurotransmitters. The results show promise for the future of clinical research on new therapies for neurodegenerative diseases. However, the studies are still limited, which does not allow us to extrapolate the results to human beings with ND. CONCLUSIONS: Therefore, clinical trials are needed in order to prove the results of the in vitro and in vivo studies, as well as to assess the ideal, safe, and effective dose of these seed extracts in patients with neurodegenerative diseases.

Selenium in Human Health and Gut Microflora: Bioavailability of Selenocompounds and Relationship With Diseases.

This review covers current knowledge of selenium in the dietary intake, its bioavailability, metabolism, functions, biomarkers, supplementation and toxicity, as well as its relationship with diseases and gut microbiota specifically on the symbiotic relationship between gut microflora and selenium status. Selenium is essential for the maintenance of the immune system, conversion of thyroid hormones, protection against the harmful action of heavy metals and xenobiotics as well as for the reduction of the risk of chronic diseases. Selenium is able to balance the microbial flora avoiding health damage associated with dysbiosis. Experimental studies have shown that inorganic and organic selenocompounds are metabolized to selenomethionine and incorporated by bacteria from the gut microflora, therefore highlighting their role in improving the bioavailability of selenocompounds. Dietary selenium can affect the gut microbial colonization, which in turn influences the host's selenium status and expression of selenoproteoma. Selenium deficiency may result in a phenotype of gut microbiota that is more susceptible to cancer, thyroid dysfunctions, inflammatory bowel disease, and cardiovascular disorders. Although the host and gut microbiota benefit each other from their symbiotic relationship, they may become competitors if the supply of micronutrients is limited. Intestinal bacteria can remove selenium from the host resulting in two to three times lower levels of host's selenoproteins under selenium-limiting conditions. There are still gaps in whether these consequences are unfavorable to humans and animals or whether the daily intake of selenium is also adapted to meet the needs of the bacteria.

Essential Oils in Experimental Models of Neuropsychiatric Disorders: A Systematic Review.

BACKGROUND: Neural cells undergo functional or sensory loss due to neurological disorders. In addition to environmental or genetic factors, oxidative stress is a major contributor to neurodegeneration. In this context, there has been a growing interest in investigating the effects of EOs (EOs) in recent years, especially in the treatment of neuropathologies. The chemical and biological effects of EOs have led to important treatment tools for the management of various neurological disorders. OBJECTIVE: In the present study we performed a systematic review that sought to comprehend the neuroprotective effects of different EOs. METHOD: This work is a systematic review where an electronic search was performed on PubMed, ScienceDirect, Cochrane Library and SciELO (Scientific Electronic Library Online) databases, covering the last 10 years, using "Essential oil" and "Neuroprotective effect" as reference terms. RESULTS: A total of 9 articles were identified, in which the efficacy of EOs was described in experimental models of anxiety, dementia, oxidative stress, cerebral ischemia, Alzheimer's disease, and oxidative toxicity. CONCLUSION: EOs from different species of medicinal plants have shown positive responses in neurological disorders such as anxiety, dementia, oxidative stress, cerebral ischemia, and oxidative toxicity. Thus, EOs emerges with the potential to be used as alternative agents in the treatment of neurological disorders.

Haloperidol-Induced Preclinical Tardive Dyskinesia Model in Rats.

Haloperidol is a first-generation antipsychotic used in the treatment of psychoses, especially schizophrenia. This drug acts by blocking dopamine D2 receptors, reducing psychotic symptoms. Notwithstanding its benefits, haloperidol also produces undesirable impacts, in particular extrapyramidal effects such as tardive dyskinesia (TD), which limit the use of this and related drugs. TD is characterized by repetitive involuntary movements occurring after chronic exposure therapy with haloperidol. Symptoms most commonly manifest in the orofacial area and include involuntary movements, tongue protrusion, pouting lips, chewing in the absence of any object to chew, and facial grimacing. The most serious aspect of TD is that it may persist for months or years after drug withdrawal and is irreversible in some patients. This unit, aimed at facilitating the study of TD, describes methods to induce TD in rats using haloperidol, as well as procedures for evaluating the animals's TD-related symptoms. © 2019 by John Wiley & Sons, Inc.

Nature as a source of drugs for ophthalmology / Natureza como fonte de drogas para oftalmologia

ABSTRACT Nature has always provided an unlimited source of biologically-active compounds. Since the beginning of mankind, humans have sought resources in fauna and flora to treat eye diseases. However, it was only after the Industrial Revolution that extracts of plants and substances of animal origin could be used safely, as has been determined by controlled interventional studies. Two major challenges faced by ocular pharmacology are the following: developing drugs that are able to reduce blindness due to glaucoma; and controlling the pain associated with eye surgery. The search for a drug that effectively lowers intraocular pressure and controls the progression of glaucoma has led to the development of various ocular hypotensive agents, such as physostigmine from the Physostigma venenosum plant. The anesthetic properties of cocaine, extracted from Erythroxylon coca, finally enabled surgical procedures in the eye. Several new natural compounds have been investigated in an attempt to identify substances with the potential to provide additional benefits to eye tissue and vision. Emerging evidence of anti-inflammatory, wound-healing, antimicrobial, antioxidant, antitumor, and antiangiogenic properties attributed to plant extracts and animal tissues has encouraged more investment in research in this area. Despite technological advances in synthesizing drugs, the pharmaceutical industry still seeks new active compounds from natural sources as well as from revisiting already-established naturally derived compounds. Although a large number of naturally-occurring compounds is known, this review article focuses on the bioactive substances with scientifically-proven benefits for ocular tissues.

RESUMO A natureza sempre se forneceu uma fonte inesgotável compostos biologicamente ativos. Desde o início da humanidade, os homens buscaram recursos na fauna e flora para tratar as doenças oculares. Porém, foi somente após a Revolução Industrial que extratos de plantas e substâncias de origem animal puderam ser utilizados com segurança, como foi determinado por estudos controlados de intervenção. Dois grandes desafios enfrentados pela farmacologia foram: desenvolver drogas capazes de reduzir a cegueira pelo glaucoma; e controlar a dor associada à cirurgia ocular. A busca por uma droga que efetivamente reduza a pressão intraocular e controle a progressão do glaucoma levou ao desenvolvimento de diversos hipotensores oculares, como a physostigmine da planta Physostigma venenosum. As propriedades anestésicas da cocaína, extraídas da Erythroxylon coca, finalmente permitiram procedimentos cirúrgicos no olho. Vários novos compostos naturais foram investigados na tentativa de identificar substâncias com potencial para fornecer benefícios adicionais ao tecido ocular e à visão. Evidências emergentes de propriedades anti-inflamatórias, de cicatrização de feridas, antimicrobianas, antioxidantes, antitumorais e antiangiogênicas atribuídas a extratos de plantas e tecidos animais estimularam mais investimentos em pesquisas nessa área. Apesar dos avanços tecnológicos na síntese de drogas, a indústria farmacêutica ainda busca novos princípios ativos a partir de fontes naturais, bem como revisita drogas derivadas já estabelecidas. Embora um grande número de compostos que ocorrem naturalmente seja conhecido, este artigo de revisão concentra-se nas substâncias bioativas com benefícios cientificamente comprovados para os tecidos oculares.

Nature as a source of drugs for ophthalmology.

Nature has always provided an unlimited source of biologically-active compounds. Since the beginning of mankind, humans have sought resources in fauna and flora to treat eye diseases. However, it was only after the Industrial Revolution that extracts of plants and substances of animal origin could be used safely, as has been determined by controlled interventional studies. Two major challenges faced by ocular pharmacology are the following: developing drugs that are able to reduce blindness due to glaucoma; and controlling the pain associated with eye surgery. The search for a drug that effectively lowers intraocular pressure and controls the progression of glaucoma has led to the development of various ocular hypotensive agents, such as physostigmine from the Physostigma venenosum plant. The anesthetic properties of cocaine, extracted from Erythroxylon coca, finally enabled surgical procedures in the eye. Several new natural compounds have been investigated in an attempt to identify substances with the potential to provide additional benefits to eye tissue and vision. Emerging evidence of anti-inflammatory, wound-healing, antimicrobial, antioxidant, antitumor, and antiangiogenic properties attributed to plant extracts and animal tissues has encouraged more investment in research in this area. Despite technological advances in synthesizing drugs, the pharmaceutical industry still seeks new active compounds from natural sources as well as from revisiting already-established naturally derived compounds. Although a large number of naturally-occurring compounds is known, this review article focuses on the bioactive substances with scientifically-proven benefits for ocular tissues.