Efecto del ácido alfa lipoico sobre la peroxidación no enzimática en mitocondrias de corazón y cerebro de rata / Effect of alpha-lipoic acid against non-enzymatic peroxidation of rat heart and brain mitochondria

RESUMEN El ácido alfa lipoico (AAL) ha sido caracterizado como un antioxidante eficiente. Se ha propuesto como un agente terapéutico potencial en el tratamiento o prevención de diferentes alteraciones que pueden estar relacionadas con un desequilibrio del estado celular oxidoreductor. El objetivo de este trabajo fue analizar la sensibilidad a la peroxidación no enzimática (PNE) (ascorbato-Fe++ dependiente) en mitocondrias de corazón y cerebro de ratas incubadas con una solución de AAL. La PNE fue evaluada por el método de quimioluminiscencia (QL). Cuando se compararon las muestras control (sin el agregado del ascorbato-Fe++) con las muestras ascorbato-Fe++ dependientes, se observó un incremento significativo en la emisión lumínica. Simultáneamente, se incubaron las mitocondrias de ambos órganos con diferentes concentraciones de AAL (0,05, 0,15 y 0,25 mg/ml) observándose una protección diferencial. Las mitocondrias de cerebro de rata incubadas con dosis de 0,15 y 0,25 mg/ml de AAL fueron protegidas de los efectos de la PNE, mientras que, en las mitocondrias cardíacas, solo se observó protección con la dosis más alta de AAL (0,25 mg/ml). El análisis de QL indicó que las mitocondrias de cerebro fueron protegidas de manera más eficiente que las mitocondrias de corazón de rata. En este último caso, será necesario probar nuevas dosis de AAL para demostrar los efectos en estas membranas. En conclusión, AAL actuó como un antioxidante protector de las membranas de ambos órganos contra el daño peroxidativo.

ABSTRACT Alphalipoc acid (ALA) has been characterized as an efficient antioxidant. It has been proposed as a potential therapeutic agent in the treatment or prevention of different pathologies that may be related to an imbalance of the oxido reductive cell state. The objective of this work was to analyze the sensitivity to non-enzymatic peroxidation (NEP) (ascorbate-Fe++ dependent) in heart and brain mitochondria of rats incubated with an ALA solution. NEP was evaluated by the chemiluminescence method (CL). When the control samples (without the addition of ascorbate-Fe++) were compared with the ascorbate-Fe++ dependent samples, a significant increase in the light emission. Simultaneously, the mitochondria of both organs were incubated with different concentrations of ALA (0.05, 0,15 and 0,25 mg/ml), observing a differential protection. Rat brain mitochondria incubated with doses of 0.15 and 0,25 mg/ml of ALA were protected from the effects of NEP, while in cardiac mitochondria, protection was only observed with the highest dose of ALA (0,25 mg/ml). The CL analysis indicated that rat brain mitochondria were protected more efficiently than rat heart mitochondria. In the latter case, it will be necessary to test new doses of ALA to demonstrate the effects on these membranes. In conclusion, ALA acted as a protective antioxidant of the membranes of both organs against peroxidative damage.

Influence of alpha lipoic acid supplementation on urinary bladder morphology of diabetic rats / Influencia de la suplementación con ácido alfa lipoico en la morfología de la vejiga urinaria de ratas diabéticas

Diabetes Mellitus (DM) is a condition marked by hyperglycaemia that causes systemic complications, including urinary vesicle dysfunction due to oxidative stress. Further, antioxidants, as well as alpha lipoic acid (ALA), may be a response to this pathological condition. The present study verified the action of ALA as a supplement in ration on glycemia and urinary vesicle structures of rats induced by streptozotocin. The rats were divided into 4 groups: Control (CG), Alpha Lipoic (ALAG), Diabetic control (DCG), and the Diabetic alpha lipoic (DALAG) group. For induction, the diabetic groups were initially induced with streptozotocin (dose 60 mg/kg). Subsequently, group glycemia was evaluated weekly. After 8 weeks, the rats were euthanized and the bladder was collected. The bladders were histologically processed and the slides were stained with Masson's Trichrome for the histomorphometry of epithelial height, connective and muscular tissue and coloration of PicroSirius Red for further analysis of collagen fibers of the bladder. The data of the glycemia demonstrated an inferior median in DALAG compared to DGC (p<0.01). The epithelial height and percentage of the muscle tissue were greater in DALAG compared to the DGC, but not significant. However, GDAL showed improvement in the organization of collagen fibers. In conclusion, bladder the morphology alterations caused by DM were not alleviated by the administration of ALA in 8 weeks of the experiments.

La diabetes mellitus (DM) es una afección marcada por hiperglucemia que causa complicaciones sistémicas, incluida la disfunción de la vejiga urinaria debido al estrés oxidativo. Además, los antioxidantes, así como el ácido alfa lipoico (ALA), pueden ser una respuesta a esta condición patológica. El presente estudio verificó la acción de ALA como suplemento en la ración sobre la glucemia y las estructuras de la vejiga urinaria de ratas inducidas por estreptozotocina. Las ratas se dividieron en 4 grupos: control (CG), alfa lipoico (ALAG), control diabético (DCG) y el grupo diabético alfa lipoico (DALAG). Para la inducción, los grupos diabéticos se aplicó estreptozotocina (dosis 60 mg/kg). Posteriormente, la glucemia grupal se evaluó semanalmente. Después de 8 semanas, las ratas se sacrificaron y se retiró la vejiga urinaria. Las vejigas se procesaron histológicamente y las muestras se tiñeron con tricromo de Masson para la histomorfometría y así evaluar la altura epitelial, el tejido conectivo y muscular. Además se tiñeron cond PicroSirius Red para un análisis posterior de las fibras colágenas de la vejiga urinaria. Los datos de la glucemia demostraron una mediana inferior en DALAG en comparación con DGC (p <0,01). La altura epitelial y el porcentaje de tejido muscular fueron mayores en DALAG en comparación con el DGC, pero no estadísticamente significativos. Sin embargo, GDAL mostró una mejora en la organización de las fibras de colágeno. En conclusión, la morfología de las alteraciones de la vejiga causada por DM no se alivió con la administración de ALA en 8 semanas de estudio.

Fulminant type 1 diabetes mellitus in pregnancy

Fulminant type 1 diabetes mellitus (FT1DM) has received clinical attention for its low incidence and poor prognosis. Currently, few cases of FT1DM are associated with pregnancy in clinical practice, but it poses a great threat to the life of mothers and infants. Here, we present two cases of FT1DM in pregnancy. In Case 1, the patient was a 26-year-old woman who was admitted to the hospital with reduced fetal movement. She was diagnosed with FT1DM and delivered a dead female fetus. Lispro and lantus were administered to control blood glucose, and lipoic acid for antioxidant therapy. In Case 2, the patient was a 28-year-old woman who developed nausea, vomiting, diarrhea, and polydipsia, which later proved to be FT1DM. An abortion was induced and blood glucose levels were controlled using an insulin pump. All physicians should be aware of this disease in order to provide prompt diagnosis and emergency treatment, thus improving maternal prognosis. We suggest that plasma glucose/hemoglobin A1C ratio be adopted as a new clinical parameter in predicting FT1DM.

Antioxidant action of alpha lipoic acid on the testis and epididymis of diabetic rats: morphological, sperm and immunohistochemical evaluation

ABSTRACT Introduction Chronic hyperglycemia is caused by diabetes mellitus-committed genital morphophysiology, and oxidative stress is one of the main factors involved in this process. Alpha lipoic acid (ALA) can prevent metabolic and morphological changes in diabetic individuals. Objectives In present study, we evaluated the effects of regular ALA consumption on the spermatogenesis and histoarchitecture in the male genital system of diabetic rats. Materials and Methods Thirty-two Wistar rats were divided into groups: Control (CG); Diabetic Control (DCG), receiving commercial diet: ALA Group (ALAG) and Diabetic ALA Group (DALAG), fed diets with added ALA (300 mg/Kg bw). The diabetic groups received a single injection of streptozotocin (60 mg/kg). After sixty days of the diet, the animals were euthanized, and semen, testis and epididymis samples were collected. A histomorphometric analysis was performed to determine the epithelial height, tubular and luminal diameter, tubular and luminal area of seminiferous tubules and each epididymal region. Sertoli cells were evidenced using the antivimenti antibody and were quantified. The results were statistically analyzed by the ANOVA test. Results At the end of the experiment, the DALAG glycemia was significantly lower than DCG. The histomorphometric parameters of the seminiferous and epididymal tubules did not show improvement in the DALAG. However, there was an improvement in the DALAG in terms of the concentration, motility and percentage of spermatic pathologies, as well as in the number of Sertoli cells (p<0.001). Conclusions The results demonstrated that supplementation with the ALA antioxidant retards testicular lesions and preserve the process of spermatogenesis in diabetes.

Effects of the supplementation with alpha-lipoic acid on muscular antioxidant biomarkers of trained mice / Efeitos da suplementação com ácido alfa-lipóico sobre biomarcadores antioxidantes musculares de camundongos treinados

BACKGROUND: Performing high intensity or exhaustive exercise can lead to muscle damage such as injuries, chronic fatigue and overtraining, partly due to the high synthesis of reactive oxygen species. The α-lipoic acid (ALA) and its reduced form, dihydrolipoic acid, act as potent antioxidant and eliminate free radicals. Although this response depends on the type of exercise and supplementation, animal and human studies have shown the benefits of antioxidant supplementation on the recovery of damages caused by exhaustive exercise, either by restoring antioxidant levels or by decreasing the damage. OBJECTIVE: We evaluated the effect of ALA supplementation on muscular biomarkers of oxidative stress following exhaustive exercise of trained mice. METHODS: Sixty mice were trained to swim for 6 weeks. On the last week, half of the animals were supplemented daily with 100 mg/kg of oral gavage of ALA in soy oil as a vehicle. The other half received just the vehicle. On the last day 20 animals from each group were submitted to an exhaustion protocol with 10% overweight attached to tail. Animals were euthanized on 3 moments: basal, just after the exhaustive protocol (0 h) and, 4 h after the exhaustive protocol. The gastrocnemius muscle was promptly excised and homogenized. The homogenates were used to estimate oxidative stress biomarkers. RESULTS: There was a simultaneous decrease of non-protein thiols and vitamin E after 4 h of exhaustive exercise in the ALA group (p<0.05) compared to the control group, suggesting the consumption of these compounds in the process of lipid peroxidation. Interestingly, there was an increase of nitrate and nitrite in ALA group (p<0.05) and a decrease in the control (p<0.05) compared to basal moment, possibly by activation of endothelial nitric oxide synthase. The total antioxidant capacity remained unchanged in the ALA group. CONCLUSION: The supplementation with ALA resulted in a protection against oxidative stress caused by exhaustive exercise.

CONTEXTO: A realização de exercício de alta intensidade ou exaustivo pode levar a danos musculares, como lesões, fadiga crônica e overtraining, em parte devido à alta síntese de espécies reativas de oxigênio. O ácido α-lipóico e sua forma reduzida, o ácido dihidrolipóico, atuam como potentes antioxidantes e eliminam os radicais livres. Apesar de depender do tipo de exercício e suplementação, estudos com animais e humanos mostram benefícios da suplementação com antioxidante na recuperação de danos causados pelo exercício exaustivo, seja restaurando os níveis de antioxidantes ou diminuindo os danos. OBJETIVO: Avaliar o efeito da suplementação com ácido α-lipóico sobre biomarcadores musculares de estresse oxidativo após o exercício exaustivo de camundongos treinados. METODOLOGIA: Os camundongos (n = 60) foram treinados em natação por 6 semanas. Na última semana, metade dos animais foram suplementados diariamente com gavagem oral de 100 mg / kg de ácido α-lipóico em óleo de soja como veículo. A outra metade recebeu apenas o veículo. No último dia 20 animais de cada grupo foram submetidos ao protocolo de exaustão com 10% de sobrepeso atado à cauda. Os animais foram eutanasiados em 3 momentos: basal, logo após o protocolo de exaustão (0 h) e 4 h após o protocolo de exaustão. O músculo gastrocnêmio foi imediatamente coletado e homogeneizado. Os homogeneizados foram usados para acessar os biomarcadores de estresse oxidativo. RESULTADOS: Houve diminuição simultânea de tióis não protéicos e vitamina E após 4 h de exercício exaustivo no grupo ácido α-lipóico (p <0,05) em relação ao grupo controle, sugerindo o consumo destes compostos no processo de peroxidação lipídica. Interessantemente, houve aumento de nitrato e nitrito no grupo ácido α-lipóico (p <0,05) e diminuição no controle (p <0,05) em relação ao momento basal, possivelmente pela ativação da óxido nítrico sintase endotelial. A capacidade antioxidante total permaneceu inalterada no grupo ácido α-lipóico. CONCLUSÃO: A suplementação com ácido α-lipóico resultou em proteção contra o estresse oxidativo causado pelo exercício exaustivo.

Tratamientos farmacológicos en pacientes con síndrome de boca urente: revisión sistemática / Pharmacologic treatment of burning mouth syndrome: a systematic review

El objetivo fue determinar mediante una revisión sistemática, cuáles tratamientos farmacológicos para el Síndrome de Boca Urente (SBU) logran una reducción de síntomas, según Escala Visual Análoga (EVA). Se realizó una búsqueda bibliográfica en la bases de datos PubMed y SciELO, Trip Database, Scopus Database, EBSCO host y LILACS entre el 2005 y 2015. De 72 artículos, se seleccionaron un total de 11. Los tratamientos sistémicos usados fueron, Hipericum perforatum, Catuama, Clonazepam, Ácido alfa lipoico y Lafutidina. Entre los tratamientos tópicos, Aceite de oliva virgen enriquecido con licopeno, Lisozima lactoperoxidasa, Clonazepam y Capsaicina. Los fármacos que obtuvieron mejores resultados para el tratamiento del SBU fueron Lafutidina, Catuama, Clonazepam tópico y sistémico, y en menor grado Capsaicina.

The aim of this study was to determine through a systematic review, which is the best drug treatment for burning mouth syndrome (SBU), measured on a Visual Analogue Scale. A scientific literature search was conducted in PubMed and SciELO, Trip Database, Database Scopus, EBSCO host and LILACS data between 2005 and 2015. Of a total of 72 articles, 11 were included for analysis. Systemic treatments were Lycopene-enriched virgin olive oil, Hypericum perforatum, Catuama, Clonazepam, Alpha lipoic acid; topical treatments were Lysozyme lactoperoxidase, Clonazepam, Capsaicin and Lafutidine. The best results obtained were with Lafutidine, Catuama, topical and systemic Clonazepam, and to a lesser degree Capsaicin.

Antioxidant therapy in the elderly with tinnitus / Efeito da terapia com antioxidantes sobre o zumbido em idosos

ABSTRACT INTRODUCTION: Several approaches have been tried for the treatment of tinnitus, from cognitive-behavioral therapies and sound enrichment to medication. In this context, antioxidants, widely used in numerous areas of medicine, appear to represent a promising approach for the control of this symptom, which often is poorly controlled. OBJECTIVE: To evaluate the effects of antioxidant therapy for tinnitus in a group of elderly patients. METHODS: Prospective, randomized, double-blinded, placebo-controlled clinical trial. The sample consisted of 58 subjects aged 60 years or older, with a complaint of tinnitus associated with sensorineural hearing loss. These individuals completed the Tinnitus Handicap Inventory (THI) questionnaire before and after six months of therapy. The treatment regimens were: Ginkgo biloba dry extract (120 mg/day), a-lipoic acid (60 mg/day) + vitamin C (600 mg/day), papaverine hydrochloride (100 mg/day) + vitamin E (400 mg/day), and placebo. RESULTS: There was no statistically significant difference between THI by degree (p = 0.441) and by score (p = 0.848) before and after treatment. CONCLUSION: There was no benefit from the use of antioxidant agents for tinnitus in this sample.

Resumo Introdução: Uma série de abordagens terapêuticas tem sido empregada no tratamento do zumbido, desde terapias cognitivo-comportamentais e de enriquecimento sonoro até terapias medicamentosas. Nesse contexto, os agentes antioxidantes, amplamente utilizados em diversas áreas da medicina, parecem representar uma perspectiva promissora para o controle desse sintoma, que muitas vezes tem um controle clínico insatisfatório. Objetivo: Avaliar os efeitos da terapia com agentes antioxidantes sobre o zumbido em um grupo de pacientes idosos. Método: Ensaio clínico prospectivo, randomizado, duplo-cego e controlado por placebo. A amostra composta de 58 indivíduos com 60 anos ou mais, com queixa clínica de zumbido associado à perda auditiva, do tipo neurossensorial, em graus variados. Esses indivíduos foram submetidos ao questionário THI (Tinnitus Handicap Inventory) antes e após 6 meses de uso da medicação. Os esquemas terapêuticos foram os seguintes: extrato seco de Ginkgo biloba(120 mg/dia), ácido a-lipóico (60 mg/dia) + vitamina C (600 mg/dia), cloridrato de papaverina(100 mg/dia) + vitamina E (400 mg/dia) e placebo. Resultados: O THI após o tratamento foi estatisticamente igual ao THI antes do tratamento, tanto em graus (p = 0,441) quanto em escores (p = 0,848). Conclusão: Não se verificou benefício estatisticamente significativo com o uso de agentes antioxidantes para o zumbido dos indivíduos avaliados.

Efeito antipsicótico da associação da clorpromazina e ácido lipóico em modelo de esquizofrenia induzido pela cetamina em ratos

A esquizofrenia, síndrome neuropsiquiátrica caracterizada por comprometimento das funções cerebrais, apresenta, além de sintomas comportamentais, alterações eletroencefalográficas, está associada a uma desregulação das respostas imunológicas e componente oxidativo. No entanto, o papel do dano oxidativo nas alterações eletroencefalográficas presentes na esquizofrenia não está completamente esclarecido. Desta maneira, este estudo teve como objetivo avaliar os efeitos antipsicóticos da associação de clorpromazina (CP) e ácido lipóico (ALA), em modelo de esquizofrenia induzido por cetamina (KET), em ratos. Foram utilizados ratos Wistar machos (200-300 g), tratados durante 10 dias e divididos em dois protocolos experimentais. No primeiro, os animais foram divididos em quatro grupos (n = 10) e tratados com solução salina (controle) ou cetamina (10, 50 ou 100 mg/kg). No segundo, os animais foram divididos em nove grupos (n = 10), tratados com solução salina (controle), ácido lipóico (100 mg/kg), cetamina (10 mg/kg), clorpromazina (1 ou 5 mg/kg) sozinha ou associada a cetamina (CP1 ou CP5+KET) ou associada ao ácido lipóico (ALA+CP1 ou CP5+KET)...

Schizophrenia, a neuropsychiatric syndrome characterized by brain functions impairment, presents besides the behavioral symptoms, electroencephalographic changes and it is associated with a dysregulation of immune responses and oxidative component. However, the role of the inflammatory and oxidative damage on the electroencephalographic alterations present in schizophrenia was not completely clarified. Thus, this study aimed to investigate the electroencephalographic, behavioural and neurochemical effects in the hippocampus of rats treated with chlorpromazine alone or associated with lipoic acid in the model of schizophrenia induced by ketamine. However, the role of oxidative damage in electroencephalographic changes present in schizophrenia is not fully understood. As a result, this study aimed to evaluate the effects of the antipsicotics association of chlorpromazine (CP) and lipoic acid (ALA) in the schizophrenia model induced by ketamine (KET) in rats. Wistar male rats (200-300 g) were tested. They were treated for 10 days and divided into two experimental protocols: At first the animals were divided into 4 groups (n = 10) and treated with saline (control) or ketamine (10, 50, or 100 mg/kg). In the second, the animals were divided into 9 groups (n = 10) treated with saline (control), lipoic acid (100mg/kg), ketamine (10mg/kg) and chlorpromazine (1 or 5 mg/kg) alone or and ketamine (CP1 and CP5+KET) or associated with lipoic acid (ALA+CP1 and CP5+KET)...

Does alfa lipoic acid prevent liver from methotrexate induced oxidative injury in rats?

PURPOSE: To determine the antioxidant and anti-inflammatory effects of alfa lipoic acid (ALA) on the liver injury induced by methotrexate (MTX) in rats. METHODS: Thirty two rats were randomly assigned into four equal groups; control, ALA, MTX and MTX with ALA groups. Liver injury was performed with a single dose of MTX (20 mg/kg) to groups 3 and 4. The ALA was administered intraperitonealy for five days in groups 2 and 4. The other rats received saline injection. At the sixth day the rats decapitated, blood and liver tissue samples were removed for TNF-α, IL-1β, malondialdehyde, glutathione, myeloperoxidase and sodium potassium-adenosine triphosphatase levels measurement and histological examination. RESULTS: MTX administration caused a significant decrease in tissue GSH, and tissue Na+, K+ ATPase activity and which was accompanied with significant increases in tissue MDA and MPO activity. Moreover the pro-inflammatory cytokines (TNF-α, IL- β) were significantly increased in the MTX group. On the other hand, ALA treatment reversed all these biochemical indices as well as histopathological alterations induced by MTX. CONCLUSION: Alfa lipoic acid ameliorates methotrexate induced oxidative damage of liver in rats with its anti-inflammatory and antioxidant effects. .

Estudo do efeito do Mito-TEMPO e do ácido lipoico sobre a cardiotoxicidade da dexorrubicina / Study of the effect of weather and Mito-lipoic acid on cardiotoxicity dexorrubicina

Introdução: A doxorrubicina (DOX) é um quimioterápico antracíclico amplamente usado para o tratamento de diversos tumores humanos, entretanto, o desenvolvimento de reações adversas à droga, em particular, cardiotoxicidade, tem limitado seu uso. Embora a toxicidade cardíaca induzida pela DOX pareça ser multifatorial, a hipótese mais investigada tem sido a formação de espécies reativas de oxigênio (ROS) e há evidências apontando para as mitocôndrias cardíacas como alvos primários da toxicidade da DOX. Esse dano oxidativo pode iniciar peroxidação lipídica e pode ser potencialmente limitado pelo uso de antioxidantes. Objetivo: O objetivo do presente estudo foi avaliar a possível eficácia do ácido lipoico (AL) e do Mito-TEMPO (Mito-T) como agentes protetores contra a cardiotoxicidade induzida pela DOX in vitro e in vivo e investigar se essa proteção pode afetar a atividade antitumoral da DOX. Método e Resultados: A capacidade do AL e Mito-T eliminar radicais livres foi avaliada usando o teste do 2,2-difenil-1-picril-hidrazila (DPPH). Menor atividade antioxidante do AL (29%) comparada ao Mito-T (63%) foi observada. DOX reduziu a viabilidade de células H9c2 (CI50 = 40,83 M, IC 95% = 28,64 – 58,21 M) e aumentou a concentração de malondialdeído (MLDA), um marcador de peroxidação lipídica, confirmando a citotoxicidade induzida pela DOX in vitro. O pré-tratamento com AL ou Mito-T não promoveu proteção contra o dano induzido pela DOX in vitro. Uma única injeção intraperitoneal (i.p.) de DOX (24 mg/kg de peso corpóreo) induziu redução significante no peso corpóreo (p<0,001), elevação da atividade sérica total de creatina quinase (p<0,05) e creatina quinase-MB (p<0,05), aumento na concentração de malondialdeído em mitocôndrias (p<0,05) e tecido cardíaco (p<0,01) em camundongos da linhagem C57BL/6 após 48 horas. O pré-tratamento dos animais com Mito-T (5 mg/kg de peso corpóreo, i.p., por dois dias, 48 e 24 horas antes da DOX) reduziu significativamente a peroxidação lipídica de mitocôndrias cardíacas (p<0,01) indicando o direcionamento do antioxidante para a mitocôndria. O tratamento com Mito-T ou AL, duas vezes, 24 e uma hora antes do tratamento com DOX, inibiu a atividade sérica de creatina quinase total (p<0,05). Além disso, o tratamento de camundongos apresentando tumor B16F10 com AL não interferiu na eficácia antitumoral da DOX. Conclusão: Os dados sugerem que a combinação de AL com DOX pode ser benéfica para o tratamento de câncer, entretanto, são necessárias novas investigações para confirmar essa suposição.

Introduction: Doxorubicin (DOX) is an anthracycline chemotherapeutic that is widely used for the treatment of many human tumours, however, the development of adverse drug reactions in particular cardiotoxicity has limited its use. Although doxorubicin-induced cardiac toxicity appears to be multifactorial, the most thoroughly investigated hypothesis has been the formation of reactive oxygen species (ROS) and there is evidence pointing to cardiac mitochondria as primary targets of the toxicity of DOX. This oxidative injury can initiate lipidic peroxidation and may be potentially limited by the use of antioxidants. Aim: The aim of the present study was to evaluate the possible efficacy of lipoic acid (LA) and Mito-TEMPO (Mito-T) as a protective agent against DOX-induced cardiotoxicity in vitro and in vivo and to investigate whether this protection may affect the antitumor activity of DOX. Method and Results: Free radical scavenging capacity of LA and Mito-T was assayed using 1,1-diphenyl-2-picrylhydrazy (DPPH) assay. Lower antioxidant activity for LA (29%) compared to Mito-T (63%) were observed. DOX reduced H9c2 viability (IC50 = 40.83 M, 95% CI = 28.64 – 58.21 M) and increased the levels of malondialdehyde (MLDA), a marker of lipid peroxidation, confirming DOX-induced cytotoxicity in vitro. Pretreatment with LA or Mito-T did not provide protection against DOX-induced damage in vitro. A single intraperitoneal (i.p.) injection of DOX (24 mg/kg body weight) induced a significant reduction in body weight (p<0.001), elevation of serum activity of total creatine kinase (p<0.05) and creatine kinase-MB (p<0.05), increase in malondialdehyde levels in cardiac mitochondria (p<0.05) and cardiac tissue (p<0.01) in C57BL/6 mice after 48 hours...

Efecto del ácido alfa lipoico y la pirfenidona en la modulación antioxidante celular contra el daño oxidativo / Effects of alpha lipoic acid and pirfenidone on liver cells antioxidant modulation against oxidative damage

Background: Liver fibrogenic processes are related to cellular redox state. Glutathione (GSH) is the major cellular antioxidant. GSH induced activation could be related to antifibrogenic effects. Aim: To explore the association between the antifibrogenic effect and pro-antioxidant mechanisms of alpha-lipoic acid (ALA) and pirfenidone (PFD). Material and Methods: HepG2 cells and primary HSC cultures were exposed to menadione 0.1 μM (MEN) as oxidative stress inducer and treated to ALA (5 mM) or PFD (10 μM, 100 μM y 1000 μM). Results: In HSC, PFD decreased cell proliferation and the expression of COL1A1, TGF-β1, TIMP1, IL6, TNFα and MCP1 induced by MEN. Furthermore it was confirmed that ALA and PFD activate diverse antioxidants mediators, however MEN decreases this response. Then, MEN, ALA and PFD induce an antioxidant response, the first one as a response to injury and the latter two as pro-antioxidant inducers. Therefore, when cells are exposed to oxidative stress, endogenous systems activate a battery of mediators that increase the antioxidant potential. When these cells are treated with ALA and PFD, de novo formation of protective genes decreases since previous elicited protection induced in response to injury, enhance ALA and PFD effects. Conclusion: Regardless of the route of action, ALA and PFD induce the biosynthesis of antioxidants mediators which is associated with modulation of fibrogenic processes.

Estatinas x ácido lipóico na prevenção e tratamento das doenças cardiovasculares / Statins x lipoic acid in the prevention and treatment of cardiovascular diseases

Cardiovascular diseases (CVD) are the leading cause of death worldwide and atherosclerosis is the most important process underlying CVD. Statins are widely used in primary and secondary prevention of CVD, though their adverse side effects, such as myopathy and hepatotoxicity, justify the search for therapeutic alternatives. Alpha lipoic acid is a potent antioxidantand its potential use to combat various conditions, such as diabetic nephropathy, metal poisoning, Alzheimer's disease and CVD has been under intense study. The aim of this review was to gather information on the use of statins and alpha lipoic acid in the prevention and treatment of CVD. The literature suggests that inaddition to the known side effects most associated with the use of statins, they can also cause reduced levels of coenzyme Q10 (CoQ10), an important mitochondrial antioxidant and electron transport chain carrier that has the capacity to antagonize oxidation of plasma lowdensity lipoprotein (LDL). The loss of CoQ10 can reduce adenosine triphosphate (ATP) levels in cardiac cells, further worsening the overall state of the individual. Alpha lipoic acid produces favorable metabolic and endothelial anti-inflammatory effects, without adverse side effects, and thus may be an alternative treatment for the prevention of CVD. However, more controlled clinical studies are needed to establish definitively the prophylactic and therapeutic potential of alpha lipoic acid and to decide whether it might be more effective than statins for the prevention and treatment of CVD...

As doenças cardiovasculares (DCVs) são a principal causa de morte no mundo e tem a aterosclerose como componente mais importante. As estatinas são extensamente utilizadas na prevenção primária e secundária das DCVs, todavia seus efeitos adversos como miopatia e toxicidade hepática justificam a busca por alternativas terapêuticas. O ácido lipóico é um potente antioxidante e vem sendo intensamente investigado no combate de diversas condições tais como nefropatia diabética, intoxicação por metais, doença de Alzheimer e nas DCVs. O objetivo desta revisão foi reunir informações acerca da utilização das estatinas e do ácido lipóico na prevenção e tratamento das DCVs. A literatura aponta que além dos efeitos adversos mais conhecidos associados ao uso das estatinas, elas também podem ocasionar a redução dos níveis de Coenzima Q10 (CoQ10), um importante antioxidante mitocondrial e transportador de elétrons, que possui a capacidade de antagonizar a oxidação da Lipoproteína de Baixa Densidade (LDL) plasmática. Ainda, a deficiência da CoQ10, por sua vez, pode levar a diminuição da adenosina trifosfato (ATP) nas células cardíacas, comprometendo ainda mais o estado global do indivíduo. Enquanto isso, o ácido lipóico apresenta favoráveis efeitos antiinflamatórios, metabólicos e endoteliais, contudo sem a presença de efeitos adversos, podendo ser uma opção terapêutica na prevenção das DCVs. Entretanto, mais estudos clínicos controlados são necessários para estabelecer de maneira definitiva os potenciais terapêuticos e profiláticos do ácido lipóico, avaliando se ele pode ser mais efetivo para a prevenção e tratamento das DCVs do que as estatinas...

Lipoic acid, but not tempol, preserves vascular compliance and decreases medial calcification in a model of elastocalcinosis

Vascular calcification decreases compliance and increases morbidity. Mechanisms of this process are unclear. The role of oxidative stress and effects of antioxidants have been poorly explored. We investigated effects of the antioxidants lipoic acid (LA) and tempol in a model of atherosclerosis associated with elastocalcinosis. Male New Zealand white rabbits (2.5-3.0 kg) were fed regular chow (controls) or a 0.5% cholesterol (chol) diet+104 IU/day vitamin D2 (vitD) for 12 weeks, and assigned to treatment with water (vehicle, n=20), 0.12 mmol·kg-1·day-1 LA (n=11) or 0.1 mmol·kg-1·day-1 tempol (n=15). Chol+vitD-fed rabbits developed atherosclerotic plaques associated with expansive remodeling, elastic fiber disruption, medial calcification, and increased aortic stiffness. Histologically, LA prevented medial calcification by ∼60% and aortic stiffening by ∼60%. LA also preserved responsiveness to constrictor agents, while intima-media thickening was increased. In contrast to LA, tempol was associated with increased plaque collagen content, medial calcification and aortic stiffness, and produced differential changes in vasoactive responses in the chol+vitD group. Both LA and tempol prevented superoxide signals with chol+vitD. However, only LA prevented hydrogen peroxide-related signals with chol+vitD, while tempol enhanced them. These data suggest that LA, opposite to tempol, can minimize calcification and compliance loss in elastocalcionosis by inhibition of hydrogen peroxide generation.

Disturbios da olfacao: estudo retrospectivo / Olfaction disorders: retrospective study

Introdução: O olfato, fenômeno subjetivo de grande importância, é pouco compreendido e estudado no ser humano. Médicos com maior conhecimento sobre os distúrbios desse sentido tendem a considerar a doença mais importante e manejar melhor o diagnóstico e o tratamento. Objetivo: Descrever a amostra dos pacientes com queixa principal de distúrbios do olfato e mostrar a experiência do serviço no manejo e tratamento. Delineamento: Estudo retrospectivo de coorte histórica com corte transversal. Materiais e métodos: Descrição da amostra e avaliação de resposta ao tratamento de pacientes com queixa principal de hiposmia ou anosmia atendidos no ambulatório de Rinologia no período de janeiro de 2005 a outubro de 2011. Resultados: Dos 38 pacientes com distúrbio da olfação, 68,4% dos pacientes apresentaram queixa de hiposmia e 31,5% de anosmia, com duração média de 30,8 meses. Os diagnósticos etiológicos principais foram idiopática (31,5%), rinopatia alérgica (28,9%) e RSC com pólipos (10,5%). As respostas ao tratamento com corticosteroide tópico e ácido alfa-lipoico foram variáveis, assim como na literatura. Conclusão: Maior importância deve ser dada aos distúrbios do olfato na prática do otorrinolaringologista, uma vez que o diagnóstico diferencial é amplo e pode trazer grande morbidade ao paciente, com impacto na sua qualidade de vida. .

Introduction: The smell, subjective phenomenon of great importance, is poorly understood and studied in humans. Physicians with more knowledge about smell disorders tend to consider the phenomenon important and to better manage the diagnosis and its treatment. Aims: First to describe a sample of patients presenting with main complaint of disturbances of smell. And second, to show our experience on management and treatment of this disease. Design: Retrospective cross-sectional cohort study. Materials and methods: Sample description and assessment of treatment response in patients with main complaint of hyposmia or anosmia from January 2005 to October 2011. Results: From 38 patients presented with main complaint of an olfactory disorder, 68.4% of the patients were presented with hyposmia and 31,5% with anosmia, with a mean duration of 30.8 months. The main etiologic diagnoses were idiopathic (31.5%), rhinitis (28.9%) and CRS with polyps (10.5%). Responses to treatment with topical steroids and alpha-lipoic acid were variable, as well as in the literature. Conclusion: Greater importance should be given to disorders of smell in practice of otolaryngologists, since its large differential diagnosis and the fact that could increase morbidity to patients, impacting on their quality of life. .

Tissue response evaluation of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant

PURPOSE: To evaluate the tissue response of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant. METHODS: A total of 20 male guinea pigs were divided into 2 groups. After paracentesis in both ears, a biodegradable polymer of poly lactic-co-glycolic acid was implanted in only one middle ear. Histological analysis using neutrophil exudate and vascular neoformation (acute inflammation) and fibroblast proliferation and mononuclear inflammatory cells (chronic inflammation) as parameters was performed after 10 and 30 days of survival (groups 1 and 2, respectively). RESULTS: Four ears in group 1 and 7 in group 2 had an increase of neutrophil exudate. Vascular neoformation occurred in ears with or without the implant, in both groups. Fibroblast proliferation and mononuclear inflammatory cells (lymphocytes and macrophages) increased in ears with implant in group 2. CONCLUSION: The tissue response by histological analysis of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant, showed no statistically significant difference between ears with or without the implant. .

Evaluation of lipoic acid topical application on rats skin wound healing

PURPOSE: To evaluate the effects of lipoic acid (thioctic acid) topical application on wound healing on rats skin, and the consequences of lipoic acid nanoencapsulation on this process. METHODS: The model used was the healing activity on wounds induced by surgical incision on rats skin (n = 44). The parameters analyzed (11 days) were wound healing rate and histology (vascular proliferation, polymorphonuclear or mononuclear cells, and collagen synthesis or reepithelialization), after application of free lipoic acid or lipoic acid- loaded nanocapsules. The antioxidant activity of these formulations was evaluated by lipid peroxidation test. RESULTS: It was demonstrated for the first time that the topical application of lipoic acid improves wound healing. On the seventh day after surgery, the animals treated with lipoic acid showed increased healing rate (60.7 ± 8.4%) compared to the negative control group (43.0 ± 17.4%), as so improvement of histological parameters. The nanoencapsulation reverted the pro-oxidant activity presented in vitro by lipoic acid, whereas diminished wound repair. CONCLUSIONS: The topical application of lipoic acid produced an increase in the skin wound healing, which may be related to its pro-oxidant activity. On the other hand, the nanoencapsulation of the lipoic acid reversed the pro-oxidant activity, although presented minor healing activity.

Efecto del ácido tióctico en los cambios clínicos, neuroconductivos e histopatológicos de la neuropatía diabética sensitivo motora distal / Effect of thioctic acid in the clinical, histopathological and neuroconductivos the distal motor sensory diabetic neuropathy

La polineuropatía diabética es la más común de las complicaciones microvasculares de la diabetes mellitus, siendo causa importante de morbilidad y mortalidad asociada a la enfermedad. Evaluar el efecto del ácido tióctico en los cambios clínicos, neuroconductivos e histopatológicos en la neuropatía diabética sensitivo motora distal. Estudio prospectivo, longitudinal, de intervención terapéutica, en pacientes que acudieron a la consulta externa y unidad cardiometabólica del Servicio de Medicina Interna del Hospital Militar “Dr. Carlos Arvelo”, a quien se les realizó historia clínica con evaluación del score sensitivo-motor, pruebas de neuroconducción y biopsia de piel, con evaluación a la semana n° 1, 4,12, 18 y 24. 30 pacientes diabéticos con criterio clínico de neuropatía diabética sensitivo motora distal. Se observó mejoría de las parestesias a partir de la semana 12 (p <0.05) de la administración del ácido tióctico a dosis de 600mg/día por vía oral. En la neuroconducción hubo aumento de la velocidad de conducción durante el post tratamiento (p<0,05). Se realizaron 12 biopsias de piel: 2 fueron positivas (16,7%) previo tratamiento y 10 negativas (83,3%) con anticuerpo PGP 9,5. En la semana 24 post tratamiento 7 positivas (58,3%) y 5 negativas (41,7%) (p<0,05). Se demostró que el tratamiento con ácido tióctico es efectivo en mejorar los síntomas y la neuroconducción en los pacientes diabéticos con neuropatía sensitivo motora distal.

Diabetic neuropathy is the most common microvascular complication of diabetes mellitus, and a major cause of morbidity and mortality. To evaluate the effect of thioctic acid in the clinical, histopathological neuroconductive and sensory motor diabetic distal neuropathy. Prospective, longitudinal, therapeutic intervention, in patients attending the outpatient and cardiometabolic consultation Internal Medicine; an assessment of sentitivo-motor score was performed and blood chemistry was measured as well as HbA1c. Neuroconduction and skin biopsy with assessment at weeks 1, 4.12, 18 and 24 were done. 30 diabetic patients with clinical criteria of distal motor sensory neuropathy were included. The clinical symptom was paresthesia, which was present from week 12 and showed improvement (p <0.05) at weeks 18 and 24 (p<0.05). Neuroconduction was measured by increased conduction velocity post treatment (p <0.05). Biopsieswere performed in 12 patients; two were positive (16.7%) after treatment and 10 negative (83.3%) for PGP 9.5 antibody. At week 24 of treatment, 7 were positive (58.3%) and 5 negative (41.7%) (p<0.05). We demonstrated effectiveness of thioctic acid after week 12 of treatment.

The life span of Drosophila melanogaster is affected by melatonin and thioctic acid / El ciclo de vida de la Drosophila melanogaster es afectado por la melatonina y el ácido tióctico

Aging and reduced longevity are due in part to the action of free radicals (FR). Melatonin (Mel) and thioctic acid (TA) are effective in protecting against the damage caused by FR. In this study, the effect of Mel and TA on the life cycle of Drosophila melanogaster was determined. We used a control group of flies, another group that was provided with Mel (0.43 mM) throughout their life cycle (Mel-c), a third group received Mel upon reaching adulthood (Mel-a) and two groups were fed with TA (2.15 mM) in the same manner (TA-c and TA-a). The number of eclosed, survival, phenotype changes, motor activity and the content of malondialdehyde (MDA) was evaluated in each group. Mel-c increased the eclosion rate and the motor activity of the flies. Mel-c and Mel-a increased the life span and decreased the concentrations of MDA. By contrast, TA-c diminished the eclosion rate, produced phenotypic changes and increased MDA levels and motor activity of the flies. TA-a extended the life span of flies, and did not alter MDA levels and motor activity when compared with the control group. In conclusion, Mel mitigated the effects caused by FR generated during aging, while TA-c increased lipid peroxidation and altered the phenotype of flies.

El envejecimiento y la disminución de la longevidad se deben, en parte, a la acción de los radicales libres (RL). La melatonina (Mel) y el ácido tióctico (AT) son antioxidantes efectivos contra el daño ocasionado por los RL. En este estudio se determinó el efecto de la Mel y el AT en el ciclo de vida de la Drosophila melanogaster. Se utilizó un grupo de moscas control, otro grupo al que se le suministró Mel (0,43 mM) durante todo su ciclo de vida (Mel-c), un tercer grupo recibió Mel al alcanzar la adultez (Mel-a) y dos grupos a los que se le suministró AT (2,15 mM) de la misma manera (AT-c y AT-a). Se evaluó el número de eclosionados, la sobrevida, el fenotipo, la actividad motora y el contenido de malondialdehído (MDA) en cada uno de los grupos. Mel-c incrementó la tasa de eclosión y aumentó la actividad motora. Mel-a y Mel-c aumentaron la sobrevida y disminuyeron las concentraciones de MDA. Por el contrario, el AT-c disminuyó la tasa de eclosión, produjo cambios fenotípicos, no afectó la sobrevida de las moscas, aumentó los niveles de MDA y la actividad motora. El AT-a extendió la duración de la vida de los animales, no alteró los niveles de MDA, ni la actividad motora al comparar con el grupo control. En conclusión, la Mel mitigó los efectos causados por los RL generados durante el envejecimiento, mientras que el AT-c aumentó la peroxidación lipídica y alteró el fenotipo de las moscas.

Evaluación del efecto del tratamiento con ácido lipoico administrado a la rata Wistar intoxicada con el fruto de Karwinskia humboldtiana / Evaluation of the effect of treatment with lipoic acid administered to the Wistar rat intoxicated with the fruit of Karwinskia humboldtiana

La ingesta accidental de fruto de Karwinskia humboldtiana ocasiona una parálisis flácida, simétrica, progresiva y ascendente, similar al síndrome de Guillain-Barré. Evoluciona en el transcurso de 3 a 12 meses hasta su recuperación total, pero los casos graves terminan en la muerte por insuficiencia respiratoria. No existe un tratamiento específico. La lesión histopatológica descrita en nervio periférico de pacientes, y animales de experimentación corresponde a una desmielinización segmentaria acompañada de degeneración Walleriana. Una de las toxinas extraídas a partir de la semilla, la T-514, ocasiona un incremento de radicales libres in vitro. Los radicales libres se han relacionado con la desmielinización que se presenta en otros tipos de neuropatías como en la diabética. Ya que la lesión ultraestructural que se presenta en los modelos animales de diabetes es similar a la que se observa en la intoxicación experimental con fruto de K. humboldtiana, se decidió administrar un potente agente antioxidante, el ácido a-lipoico en un modelo de intoxicación crónica por fruto de K. humboldtiana. Sin embargo, no se observó mejoría sobre las manifestaciones clínicas evaluadas en los animales o sobre las lesiones histopatológicas presentes en el nervio periférico. Estos resultados sugieren que los radicales libres no son el mecanismo principal de lesión sobre el nervio periférico en la polineuropatía causada por K. humboldtiana.

The accidental ingestion of Karwinskia humboldtiana causes a flaccid, symmetrical, progressive and ascending paralysis, similar to Guillain-Barre syndrome. It evolves over the course of 3 to 12 months until full recovery, but severe cases end in death due to respiratory failure. There is no specific treatment. The histopathological lesions described in peripheral nerve of patients and in experimental animals, corresponds to segmental demyelination accompanied by Wallerian degeneration. One of the toxins extracted from the seed, T-514, causes an increase of free radicals in vitro. Free radicals have been associated to demyelination that occurs in other types of neuropathy such as diabetic neuropathy. Since the ultrastructural damage that occurs in animal models of diabetes is similar to that observed in experimental poisoning with the fruit of K. humboldtiana, we decided to administer a powerful antioxidant, a-lipoic acid, in a model of chronic poisoning due of K. humboldtiana. However, no improvement was observed on the clinical manifestations evaluated in animals or in the histopathological lesions in the peripheral nerve. These results suggest that free radicals are not the primary mechanism of injury on the peripheral nerve caused by K. humboldtiana.

Lipoic acid effects on glutamate and taurine concentrations in rat hippocampus after pilocarpine-induced seizures / Efeitos do ácido lipóico nas concentrações de glutamato e taurina no hipocampo de ratos após convulsões induzidas por pilocarpina

Pilocarpine-induced seizures can be mediated by increases in oxidative stress and by cerebral amino acid changes. The present research suggests that antioxidant compounds may afford some level of neuroprotection against the neurotoxicity of seizures in cellular level. The objective of the present study was to evaluate the lipoic acid (LA) effects in glutamate and taurine contents in rat hippocampus after pilocarpine-induced seizures. Wistar rats were treated intraperitoneally (i.p.) with 0.9 percent saline (Control), pilocarpine (400 mg/kg, Pilocarpine), LA (10 mg/kg, LA), and the association of LA (10 mg/kg) plus pilocarpine (400 mg/kg), that was injected 30 min before of administration of LA (LA plus pilocarpine). Animals were observed during 24 h. The amino acid concentrations were measured using high-performance liquid chromatograph (HPLC). In pilocarpine group, it was observed a significant increase in glutamate content (37 percent) and a decrease in taurine level (18 percent) in rat hippocampus, when compared to control group. Antioxidant pretreatment significantly reduced the glutamate level (28 percent) and augmented taurine content (32 percent) in rat hippocampus, when compared to pilocarpine group. Our findings strongly support amino acid changes in hippocampus during seizures induced by pilocarpine, and suggest that glutamate-induced brain damage plays a crucial role in pathogenic consequences of seizures, and imply that strong protective effect could be achieved using lipoic acid through the release or decrease in metabolization rate of taurine amino acid during seizures.

As convulsões induzidas pela pilocarpina podem ser mediadas através do aumento do estresse oxidativo cerebral e das alterações na concentração dos aminoácidos. O presente estudo sugere que compostos antioxidantes podem produzir neuroproteção contra a neurotoxicidade em nível celular causada pelas convulsões. O objetivo deste estudo foi avaliar os efeitos do ácido lipóico (AL) no conteúdo de glutamato e taurina no hipocampo de ratos durante convulsões induzidas por pilocarpina. Ratos Wistar foram tratados por via intraperitoneal com solução salina 0,9 por cento (controle), pilocarpina (400 mg/kg, pilocarpina), AL (10 mg/kg) e com a associação de AL (10 mg/kg); 30 min após com pilocarpina (400 mg/kg), que foi injetada 30 min após a administração de AL (AL + pilocarpina). Os animais foram observados durante 24 horas. As concentrações de aminoácidos foram determinadas por HPLC. No hipocampo dos ratos do grupo pilocarpina foi observado um aumento significativo de 37 por cento na concentração de glutamato e uma diminuição de 18 por cento no nível de taurina, quando comparado ao grupo controle. O pré-tratamento com o antioxidante reduziu significativamente o nível de glutamato em 28 por cento e aumentou em 32 por cento os níveis de taurina no hipocampo dos ratos, quando comparado ao grupo pilocarpina. Nossos resultados sugerem que ocorrem alterações na concentração dos aminoácidos no hipocampo de ratos durante as convulsões induzidas por pilocarpina, e que o glutamato pode desempenhar um papel crucial na fisiopatologia das convulsões, e que o efeito protetor poderia ser alcançado com pré-tratamento com ácido lipóico, provavelmente pelo aumento da liberação ou redução da taxa de metabolização dos aminoácidos durante as convulsões.