Nesse estudo, nós avaliamos o efeito da nicotina sobre a oxidação da LDL pelo sistema MPO/H2O2/Cl- e o efeito do HOCl sobre a LDL e alguns de seus componentes, tais como metil linoleato, vitamina E e o aminoácido triptofano. Nicotina, em concentração micromolar, amplia a oxidação do triptofano, livre em solução ou presente na LDL. A nicotina promove a diminuição da formação de dienos conjugados e consumo de oxigênio no sistema metil linoleato/HOCl, e houve evidência que sugere aumento na formação de clorohidrinas. O aumento da oxidação da vitamina E pelo HOCl também foi observada na presença de nicotina. Esses dados mostram que a interação da nicotina e HOCl pode promover alterações bioquímicas significativas na partícula de LDL e alguns de seus componentes envolvidos na patogênese de doenças cardiovasculares e de outras doenças.

In this study, the effect of nicotine on the LDL oxidation by the MPO/H2O2/Cl- system and the effect of HOCl on LDL and some of its components, such as methyl linoleate, vitamin E and the amino acid tryptophan were explored. Nicotine, in micromolar concentrations, enhanced the tryptophan oxidation, either present in LDL or free, in solution. Nicotine also decreased the formation of conjugated dienes and oxygen consumption in a methyl linoleate / HOCl system, and there was evidence to suggest an increase in chlorohydrin formation. Acceleration of the vitamin E oxidation by HOCl was also observed in the presence of nicotine. These data show that the interaction of nicotine and HOCl can promote significant biochemical modifications in LDL particle and some of its components involved in the pathogenesis of cardiovascular and other diseases.

Cogumelos apresentam propriedades nutricionais e medicinais bastante empregadas na manutenção da saúde humana e têm sido considerado por pesquisadores como possíveis fontes de seqÜestradores de radicais livres. Neste trabalho, as propriedades antioxidantes de extratos aquosos de Agaricus blazei Murill, produzidos por maceração e decocção, são demonstrados in vitro. A resistência à oxidação é demonstrada através de três mecanismos: i) inibição de processos oxidativos enzimáticos, with 100% de inibição da HRP (horseradish peroxidase) e MPO (myeloperoxidase); ii) inibição do estresse oxidativo celular, com 80% de inibição do oxidative burst de neutrófilos polimorfonucleares (PMN) e iii) ação direta sobre espécies reativas, com 62% e 87% de supressão do HOCl e ânion superóxido (O2• –), respectivamente. A partir destes dados, concluise que o extrato aquoso deste cogumelo tem significativa capacidade antioxidante, indicando sua possível aplicação para propósitos nutracêuticos e medicinais.

Mushrooms possess nutritional and medicinal properties that have long been used for human health preservation and that have been considered by researchers as possible sources of free radical scavengers. In this work, the antioxidant properties of water extracts from Agaricus blazei Murill, produced by maceration and decoction, are demonstrated in vitro. Resistance to oxidation is demonstrated through three mechanisms: i) inhibition of enzymatic oxidative process, with 100% inhibition of HRP (horseradish peroxidase) and MPO (myeloperoxidase); ii) inhibition of cellular oxidative stress, with 80% inhibition of the oxidative burst of polymorphonuclear neutrophils (PMNs); and iii) direct action over reactive species, with 62% and 87% suppression of HOCl and superoxide anion radical (O2• –), respectively. From the data, it was concluded that the aqueous extract of A. blazei has significant antioxidant activity, indicating its possible application for nutraceutical and medicinal purposes.

Astilbin (5,7,3’,4’-tetrahydroxy-2,3-dihydroflavonol-3-ß-o-rhamnoside), a flavonoid with a large range of biological activities, was isolated from Dimorphandra mollis, a shrub common to the Brazilian Cerrado. The purpose of this study is to verify the effects of astilbin on myeloperoxidase (MPO) and horseradish peroxidase (HRP), and its antioxidant activity against hypochlorous acid (HOCl) and total antioxidant activity (TAC) by the 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS•+). Astilbin inhibited MPO and HRP activities in a concentration-dependent relationship and effectively scavenged HOCl. The TAC by ABTS•+ of astilbin (IC50 ~ 20 mM) was higher than that of uric acid, which was used as a positive control. These data demonstrate that astilbin is a potent antioxidant and that it inhibits MPO and HRP activities efficiently.

Tem sido atribuído ao flavonóide kaempferitrina e ao alcalóide galegina efeito hipoglicêmico. Folha de Pterogyne nitens, por conter tais compostos, poderia ser antidiabética. Assim, avaliamos o efeito do tratamento com Pterogyne nitens a ratos diabéticos sobre níveis glicêmicos e parâmetros fisiológicos. Ratos diabéticos (50 mg estreptozotocina/Kg peso) foram tratados durante 32 dias, 2 vezes ao dia, por gavagem com extrato etanólico de folhas de Pterogyne nitens (76 mg/0,5 mL glicerina 10% por rato) (DTPn). Grupos diabéticos controles foram tratados com: glicerina 10% (0,5 mL) (DTG), insulina (2,5 U/0,3 mL) (DTI) e água (0,5 mL) (DTA). Semanalmente determinamos: peso corporal, ingestão hídrica e alimentar, volume urinário e nível glicêmico. Os resultados dos grupos DTPn, DTG e DTA foram diferentes do DTI para todos os parâmetros, ocorrendo ganho de peso corporal e redução dos demais parâmetros no DTI. O grupo DTPn apresentou resultados semelhantes aos DTG e DTA. Através dos resultados apresentados no grupo DTI, constatamos que o modelo de estudo foi adequado. Também concluímos que o extrato vegetal e a glicerina não melhoraram e nem exacerbaram o quadro diabético. Resta a possibilidade da planta promover melhoria do diabetes com diferente: dose do extrato, via de administração ou severidade do diabetes induzido.

Kaempferitrin (a flavonoid) and galegin (an alkaloid) have been indicated as hypoglycemic agents. Leaves of Pterogyne nitens, which contain both compounds, might be antidiabetic. We therefore treated diabetic rats with these leaves to observe the effects on their glycemia and physiological variables. Streptozotocin-diabetic rats were given ethanolic extract of the leaves (76 mg in 0.5 mL 10% glycerol) (DTPn), twice a day by gavage for 32 days. Diabetic controls were given 0.5 mL 10% glycerol (DTG), insulin (2.5 U in 0.3 mL) (DTI) or 0.5 mL water (DTA). During this treatment, we measured level of glycemia, the body weight, daily food and water intake and urine volume, once each week. The results for the DTPn, DTG and DTA groups all differed significantly from these for the DTI group. The latter exhibited greater body weights and lower physiological variables and glycemia than the groups DTPn, DTG and DTA, all of which gave similar results. From the data for DTI rats, we conclude that the study model was appropriate. Therefore, the plant extract (plus glycerol) neither improved nor worsened the diabetic state of the rats. It is possible that this plant might ameliorate diabetes experimental if the dose of extract, treatment route or severity of induced diabetes were altered.

Considerando-se a qualidade dos fitoterápicos, é importante salientar que a preocupação com esta questão inclui rigoroso acompanhamento das diferentes etapas do desenvolvimento e produção destes produtos, desde a coleta do vegetal até a disponibilidade do produto final. Neste trabalho, foram realizados o controle da qualidade, o potencial antioxidante como também ensaios biológicos in vitro do fruto da goiabeira (Psidium guajava L.), para o desenvolvimento de uma formulação fitocosmética. Os resultados obtidos mostraram que o fruto apresenta taninos e flavonóides, bem como atividades antioxidante e antimicrobiana. A análise microbiológica não apresentou crescimento de patógenos na formulação desenvolvida entre os outros testes realizados. Destaca-se a importância do estabelecimento do controle da qualidade para as plantas, a fim de que sejam utilizadas para o desenvolvimento de uma formulação fitocosmética segura, eficaz e com qualidade.

Considering the quality of the phytotherapic products, it is important to point out that the concern with this question includes rigorous accompaniment of the different stages of the development and production of these products, since the collection of the vegetable until the availability of the end product. In this work the quality control, the antioxidant potential were performed as also biological assays in vitro of guava fruit (P. guajava L.), for the development of a phytocosmetic formulation. The results had shown that the fruit presents tannins and flavonoids, as well as antioxidant and antimicrobial activities. The microbiological analysis did not present growth of pathogens. The importance of the establishment of the quality control for the plants is relevant, so that they are used for the development of a phytocosmetic formulation considered safe, efficient and with quality.

There is abundant evidence that reactive oxygen species are implicated in several physiological and pathological processes. To protect biological targets from oxidative damage, antioxidants must react with radicáis and other reactive species faster than biological substrates do. The aim of the present study was to determine the in vitro antioxidant activity of aqueous extracts from leaves of Bauhinia forficata Link (Fabaceae - Caesalpinioideae) and Cissus sicyoides L. (Vitaceae) (two medicinal plants used popularly in the control of diabetes mellitus), using several different assay systems, namely, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) decolorization, superoxide anión radical (0(2)•-) scavenging and myeloperoxidase (MPO) activity. In the ABTS assay for total antioxidant activity, B. forficata showed IC50 = 8.00±0.07 μg/mL, while C. sicyoides showed IC50 = 13.0±0.2 μg/mL. However, the extract of C. sicyoides had a stronger effect on 0(2)•- (IC50 = 60.0±2.3 μg/mL) than the extract of B. forficata (IC50 = 90.0±4.4 μg/ mL). B. forficata also had a stronger inhibitory effect on MPO activity, as measured by guaiacol oxidation, than C. sicyoides. These results indicate that aqueous extracts of leaves of B. forficata and C. sicyoides are a potential source of natural antioxidants and may be helpful in the prevention of diabetic complications associated with oxidative stress.

Smith-Lemli-Opitz syndrome (SLOS) or RSH syndrome comprises multiple congenital anomalies and mental retardation. The underlying defect is a deficiency in the activity of delta7-sterol reductase, which decreases cholesterol and increases 7-dehydrocholesterol (7-DHC) levels. Our aim was to identify and evaluate the frequency of SLOS manifestations in a group of Brazilian patients. Based on our own data and those reported previously, we present a simple method that allows the estimation of probabilities favoring the diagnosis of SLOS. We evaluated 30 patients clinically and determined their plasma levels of cholesterol and 7-dehydrocholesterol. In 11 patients, the diagnosis was confirmed by ultraviolet spectrophotometry (UV). Of 19 patients with normal laboratory results, 17 showed a high probability favoring the diagnosis of SLOS. The most significant signs and symptoms observed in over 2/3 of the biochemically confirmed cases were mental retardation (10/11), delayed neuropsychomotor development (10/11), syndactyly of 2nd/3rd toes (10/11), and craniofacial anomalies including microcephaly (11/11), incompletely rotated ears (8/11), palpebral ptosis (10/11), anteverted nostrils (10/11), and micrognathia (9/11). Genital anomalies were found in all male patients (6/6).