Vitamin C administration attenuated artemether induced hepatic injury in rats / La aAdministración de vitamina C atenúa la lesión hepática inducida por artemeter en ratas

This research was designed to investigate the potential protective effect of vitamin C supplementation against hepatocyte ultrastructural alterations induced by artemether (antimalarial drug) administration. Twenty-four adult male albino rats were used in this study and were divided into four groups (n=6). Group I served as a control and rats in group II administrated artemether (4 mg/kg B.W) orally for three consecutive days. Group III administered artemether plus a low dose of vitamin C (2.86 mg/kg/l water) while group IV received artemether plusa high dose of vitamin C (8.56 mg/kg). At the end of the experimental period (14 days), the harvested liver tissues were examined by transmission electron microscopy (TEM), and blood samples were assayed for biomarkers of liver injury and oxidative stress. Artemether significantly (p<0.05) augmented biomarkers of liver injury such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and oxidative stress such as superoxide dismutase (SOD), Glutathione Peroxidase (GPX), and caused degeneration and damage of the rough endoplasmic reticulum and disrupted mitochondria. The blood sinusoids were also damaged with distortion of their canaliculi. Administration of vitamin C showed improvement of liver biomarkers, and liver parenchyma, especially in a high dose of vitamin C.We concludes that vitamin C is a partial protective agent against artemether-induced liver injury.

Esta investigación fue diseñada para investigar el posible efecto protector de la vitamina C contra las alteraciones ultraestructurales de los hepatocitos, inducidas por la administración de arteméter (medicamento antipalúdico). En el estudio se utilizaron 24 ratas albinas macho adultas y se dividieron en cuatro grupos (n = 6). El grupo I fue designado como control y las ratas en el grupo II se adminstró Arteméter (4 mg / kg de peso corporal) por vía oral durante tres días consecutivos. En el grupo III se administró arteméter, además de una dosis baja de vitamina C (2,86 mg / kg / l de agua) mientras que el grupo IV recibió arteméter más una dosis alta de vitamina C (8,56 mg / kg). Al final del período experimental (14 días), los tejidos hepáticos recolectados se examinaron por microscopía electrónica de transmisión (MET), y las muestras de sangre se analizaron en busca de biomarcadores de daño hepático y estrés oxidativo. El arteméter aumentó significativamente (p <0,05) los biomarcadores de daño hepático como alanina aminotransferasa (ALT), aspartato aminotransferasa (AST) y estrés oxidativo como superóxido dismutasa (SOD), glutatión peroxidasa (GPX) y causó degeneración y daño de la retículo endoplásmico rugoso y mitocondrias alteradas. Los sinusoides sanguíneos también fueron dañados con la distorsión de sus canalículos. La administración de vitamina C mostró una mejoría de los biomarcadores hepáticos y el parénquima hepático, especialmente en una dosis alta de vitamina C. Concluimos que la vitamina C es un agente protector parcial contra la lesión hepática inducida por arteméter.

O carvedilol potencializa o efeito antioxidante das vitaminas E e C na cardiopatia chagásica crônica / Carvedilol enhances the antioxidant effect of vitamins E and C in chronic chagas heart disease

FUNDAMENTO: A doença de Chagas continua a ser uma importante doença endêmica no país, sendo o acometimento cardíaco a sua manifestação mais grave. OBJETIVO: Verificar se o uso concomitante de carvedilol potencializará o efeito antioxidante das vitaminas E e C na atenuação do estresse oxidativo sistêmico na cardiopatia chagásica crônica. MÉTODOS: Foram estudados 42 pacientes com cardiopatia chagásica, agrupados de acordo com a classificação modificada de Los Andes, em quatro grupos: 10 pacientes no grupo IA (eletrocardiograma e ecocardiograma normais: sem envolvimento do coração), 20 pacientes do grupo IB (eletrocardiograma normal e ecocardiograma anormal: ligeiro envolvimento cardíaco), oito pacientes no grupo II (eletrocardiograma e ecocardiograma anormais, sem insuficiência cardíaca: moderado envolvimento cardíaco) e quatro pacientes no grupo III (eletrocardiograma e ecocardiograma anormais com insuficiência cardíaca: grave envolvimento cardíaco). Os marcadores de estresse oxidativo foram medidos no sangue, antes e após um período de seis meses de tratamento com carvedilol e após seis meses de terapia combinada com vitaminas E e C. Os marcadores foram: atividades da superóxido dismutase, catalase, glutationa peroxidase, glutationa S-transferase e redutase, mieloperoxidase e adenosina deaminase, e os níveis de glutationa reduzida, de espécies reativas do ácido tiobarbitúrico, proteína carbonilada, vitamina E e óxido nítrico. RESULTADOS: Após o tratamento com carvedilol, todos os grupos apresentaram diminuições significativas dos níveis de proteína carbonilada e glutationa reduzida, enquanto os níveis de óxido nítrico e atividade da adenosina aumentaram significativamente apenas no grupo menos acometido (IA). Além disso, a maioria das enzimas antioxidantes mostrou atividades diminuídas nos grupos menos acometidos (IA e IB). Com a adição das vitaminas ao carvedilol houve diminuição dos danos em proteínas, nos níveis de glutationa e na maior parte da atividade das enzimas antioxidantes. CONCLUSÕES: A queda dos níveis de estresse oxidativo, verificada pelos marcadores testados, foi mais acentuada quando da associação do fármaco carvedilol com as vitaminas antioxidantes. Os dados sugerem que tanto o carvedilol isoladamente como sua associação com as vitaminas foram eficazes em atenuar o dano oxidativo sistêmico em pacientes com CC, especialmente aqueles menos acometidos, sugerindo a possibilidade de sinergismo entre esses compostos.

BACKGROUND: Chagas disease is still an important endemic disease in Brazil, and the cardiac involvement is its more severe manifestation. OBJECTIVE: To verify whether the concomitant use of carvedilol will enhance the antioxidant effect of vitamins E and C in reducing the systemic oxidative stress in chronic Chagas heart disease. METHODS: A total of 42 patients with Chagas heart disease were studied. They were divided into four groups according to the modified Los Andes classification: 10 patients in group IA (normal electrocardiogram and echocardiogram; no cardiac involvement); 20 patients in group IB (normal electrocardiogram and abnormal echocardiogram; mild cardiac involvement); eight patients in group II (abnormal electrocardiogram and echocardiogram; no heart failure; moderate cardiac involvement); and four patients in group III (abnormal electrocardiogram and echocardiogram with heart failure; severe cardiac involvement). Blood levels of markers of oxidative stress were determined before and after a six-month period of treatment with carvedilol, and six months after combined therapy of carvedilol with vitamins E and C. The markers analyzed were as follows: activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase and reductase, myeloperoxidade and adenosine deaminase; and the levels of reduced glutathione, thiobarbituric-acid reactive substances, protein carbonyls, vitamin E, and nitric oxide. RESULTS: After treatment with carvedilol, all groups showed significant decrease in protein carbonyls and reduced glutathione levels, whereas nitric oxide levels and adenosine activity increased significantly only in the less severely affected group (IA). In addition, the activity of most of the antioxidant enzymes was decreased in the less severely affected groups (IA and IB). By combining the vitamins with carvedilol, a reduction in protein damage, in glutathione levels, and in the activity of most of the antioxidant enzymes were observed. CONCLUSIONS: The decrease in oxidative stress levels observed by means of the markers tested was more significant when carvedilol was used in combination with the antioxidant vitamins. The findings suggest that both carvedilol alone and in combination with the vitamins were effective in attenuating the systemic oxidative stress in patients with Chagas heart disease, especially those less severely affected, thus suggesting the possibility of synergism between these compounds.