Antioxidant properties of species from the Brazilian cerrado by different assays / Avaliação da propriedade antioxidante de espécies do cerrado no Brasil detectada por diferentes ensaios

The purpose of this study was to screen the antioxidant activity of medicinal plant extracts from the Brazilian cerrado, through other methods than the total phenolic content and its correlation with the antioxidant activity. Ethanolic extracts of ten species were evaluated through three antioxidant assays, in vitro, including 2,2-diphenyl-1-picrylhydrazyl (DPPH), total antioxidant activity and reducing power; and by using the Folin-Ciocalteu method the total phenolic content was determined. Ethanolic extracts of Stryphnodendron obovatum, Cecropia pachystachya and Duguetia furfuraceae showed strong antioxidant activity (IC50<5 µg mL-1) in the DPPH free radical scavenging assay; the species Vernonia phosphorea, Hymenaea stignocarpa and Jacaranda ulei may also be highlighted. These results were confirmed in the assays of total antioxidant capacity and reducing power. The extracts of S. obovatum and V. phosphorea showed an abundant phenolic content; therefore, the phenolic content may play a role in the antioxidant activity. These two species, traditionally used in Brazil, showed great power in these assay systems and may be a promising source for the development of natural antioxidants and future candidates for phytochemical and pharmacological studies in related diseases.

O objetivo desse trabalho foi triar a atividade antioxidante de extratos de plantas medicinais do cerrado do Brasil, por outros métodos além do conteúdo de fenóis totais e sua correlação com a atividade antioxidante. Assim, o extrato etanólico de dez espécies vegetais do cerrado brasileiro foi avaliado por três ensaios de atividade antioxidante, in vitro: 2,2-difenil-1-picrilhidrazil (DPPH); atividade antioxidante total e poder redutor; e o teor de fenóis determinado pelo reagente de Folin-Ciocalteu. O extrato etanólico de Stryphnodendron obovatum, Cecropia pachystachya e Duguetia furfuraceae apresentaram forte atividade antioxidante (CI50<5 mg mL-1) no ensaio com o DPPH, tendo destaque também as espécies Vernonia phosphorea, Hymenaea stignocarpa e Jacaranda ulei. Os extratos de S. obovatum e V. phosphorea demonstraram maiores teores de fenóis, indicando que esse grupo de substâncias possa ser a responsável pela atividade antioxidante. Essas duas espécies, usadas tradicionalmente no Brasil, representam fontes promissoras para o desenvolvimento de antioxidantes naturais e futuros estudos fitoquímicos e farmacológicos em doenças relacionadas.

Avaliação das atividades antioxidante, antimicrobiana e citotóxica de Couepia grandiflora Benth. (Chrysobalanaceae) / Evaluation of cytotoxicity, antioxidant, antibacterial and antifungal activities of Couepia grandiflora Benth. (Chrysobalanaceae)

Couepia grandiflora Benth. é conhecida popularmente como fruta-de-ema, pertence à família Chrysobalanaceae, e ocorre em regiões tropicais e subtropicais. Plantas dessa família são utilizadas pelas populações, principalmente, para o tratamento da diarréia, disenteria e malária. Neste trabalho, avaliou-se as atividades citotóxica, antibacteriana, antifúngica e antioxidante dos extratos hexânico e etanólico de C. grandiflora. O teste com Artemia salina usado para avaliar a citotoxicidade dos extratos hexânico e etanálico apresentou valores de CL50 de 0,1082 mg/mL e 0,1408 mg/mL, respectivamente. O extrato etanálico de C. grandiflora mostrou atividade antibacteriana contra Staphylococcus aureus e Pseudomonas aeruginosa, enquanto que o extrato hexânico mostrou atividade somente contra P aeruginosa. Os dois extratos não mostraram atividade contra Escherichia coli. As Concentrações Inibitórias Mínimas (CIM) do extrato etanólico foram de 188, 125, 188 μL/mL, para Staphylococcus aureus, Escherichia coli e Pseudomonas aeruginosa, respectivamente. Quanto à avaliação da atividade antioxidante, os extratos hexânico e etanólico mostraram-se ativos com valores de CE50= 3,1 e 5,6 μg/mL, respectivamente, quando comparados com os padrões. Na avaliação da atividade antifúngica, os extratos etanálico e hexânico de C. grandiflora não apresentaram tal atividade. Conclui-se que os extratos etanólico e hexânico de C. grandiflora demostraram atividades antibacteriana, antioxidante e citotoxicidade frente à Artemia salina e ausência de atividade antifúngica.

Couepia grandiflora Benth., known popularly as ema fruit, belongs to the family Chrysobalanaceae, and is distributed in tropical and subtropical areas. Plants of this family are used mainly for the treatrnent of the diarrhea. dysentery and malaria. In this work, it was evaluated the cytotoxic, antibacterial, antifungal and antioxidant activíties of the hexane and ethanolic extracts from C. grandiflora. The cytotoxic activíty of the hexane and ethanolic extracts showed a LC50 of 0.1082 mg/mL and 0.1408 mg/mL, respectively. The ethanolic extract of C. grandiflora showed antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa. while the hexane extract showed activity just against P. aeruginosa. The two extracts did not show activity against Escherichia coli. The Minímum Inhibitory Concentrations (MIC) of the ethanolic extract were 188, 125 and 188 μL/mL for Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, respectively. The evaluation of the antioxidant activity of the hexane and ethanolic extracts showed good results when compared to the reference drugs(EC50=3.1 and 5.6 mg/mL, respectively). It was not detected antifungal activity for hexane and ethanolic extracts from C. grandiflora.

Avaliação de atividades biológicas das sementes de Stryphnodendron obovatum Benth. (Leguminosae) / Evaluation of biological activities of the seeds of Stryphnodendron obovatum Benth. (Leguminosae)

Stryphnodendron obovatum Benth., conhecido como "barbatimão", é uma espécie pertencente à família Leguminosae, sub-família Mimosoideae, e é amplamente distribuído em campos e cerrados. Na medicina popular, cascas de S. obovatum são usadas no tratamento de processos inflamatórios, como cicatrizante, para diarréia, frieira. Neste trabalho investigou-se a presença de proteínas e as atividades citotóxica, antibacteriana, antifúngica do extrato salino das sementes de S. obovatum. O extrato salino S. obovatum não apresentou toxidade frente ao ensaio com Artemia salina, nem mostrou atividade antibacteriana contra Staphylococcus aureus, Pseudomonas aeruginosa e Escherichia coli. Na avaliação da atividade antioxidante, o extrato salino apresentou uma CE50 de 12, 193 µg/mL, enquanto a do padrão positivo BHT foi 2,98 µg/mL. O extrato salino de S. obovatum não apresentou atividade antifúngica, tanto na técnica de bioautografia com o fungo Cladosporium sphaerospermum, quanto no método de difusão em disco, realizado com Candida albicans. Foi realizado teste de atividade enzimática na qual observou-se a hidrólise do substrato H-D-Benzoil-arginina-p-nitroanilida (Bz-Arg-pNan).

Stryphnodendron obovatum Benth., popularly known as "barbatimão", belongs to the Leguminosae fami/y, of the Mimosoideae subfamily, and is present in fields and in "cerrados". S. obovatum bark is used in popular medicine for treating inflammatory processes, for healing wounds, and as cure for diarrhea and chílblain. This research investigates the presence of proteins and the cytotoxic, antifungal, antibacterial and antioxidant activities of the S. obovatum seed saline extract. The saline extract did not show cytotoxicity against Artemia salina nor any antibacterial activíty against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia colí. The evaluation of the antioxidant activity showed a CEso=12.193 µg/mL, and the BHT positive pattern presented 2.98 µg/mL. The S. obovatum saline extract was tested against Cladosporium sphaerospermum and Candida albicans, using the bioautography technique and the disk diffusion method. Benzoyl­arginine-p-nitroanilide (Bz-Arg-pNan) was hydrolyzed by the saline extract.

Primary structure of Dioclea glabra trypsin inhibitor, DgTI, a Bowman-Birk inhibitor.

A novel serine proteinase inhibitor, DgTI, was purified from Dioclea glabra seeds by acetone precipitation, and ion-exchange and reverse phase chromatography. The inhibitor belongs to the Bowman-Birk family, and its primary sequence, determined by Edman degradation and mass spectrometry, of 67 amino acids is: SSGPCCDRCRCTKSEPPQCQCQDVRLNSCHSACEACVCSHSMPGLCSCLDITHFCHEPCKSSGDDED++ +. Although two reactive sites were determined by susceptibility to trypsin (Lys(13) and His(40)), the inhibitory function was assigned only to the first site. The inhibitor forms a 1:1 complex with trypsin, and Ki is 0.5 x 10(-9) M. Elastase, chymotrypsin, kallikreins, factor Xa, thrombin, and plasmin were not inhibited. By its properties, DgTI is a Bowman-Birk inhibitor with structural and inhibitory properties between the class of Bowman-Birk type I (with a fully active second reactive site), and Bowman-Birk type II (devoid of second reactive site).

Plant serine proteinase inhibitors. Structure and biochemical applications on plasma kallikrein and related enzymes.

The action of two Bowman-Birk and several plant Kunitz-type inhibitors were studied on trypsin, chymotrypsin, plasma kallikrein and factor XII. The primary structure of some of them was completely defined. The results showed that the Bowman-Birk type inhibitors, although potent inhibitors for trypsin (Ki in the range of 1-2 nM), are not able to inhibit plasma kallikrein. Factor XII (Ki = 1.4 microM) and chymotrypsin (Ki = 5.0 nM) are inhibited by Torresea cearensis trypsin inhibitor (TcTI) but not by Dioclea glabra trypsin inhibitor (DgTI). Both inhibitors reactive site regions are highly homologous, and the amino acid residues in P1 position are the same, Lys and His; major differences are in the charge of the C-terminal portion of the molecules. The studied Kunitz-type inhibitors were all able to inhibit plasma kallikrein (Ki between 4 and 80 nM), with the exception of Schizolobium parahyba chymotrypsin inhibitor (SpCI), that is specific for chymotrypsin. All Kunitz-type inhibitors inactivate chymotrypsin, but with a dissociation constant in the range of 0.1 to 0.6 microM. Factor XIIf is inhibited with Ki in the range of 0.1 microM. Bauhinia bauhinioides trypsin inhibitor (BbTI) did not promote factor XIIf inhibition. The Kunitz-type inhibitors are a highly homologous, sharing 60% identity in the N-terminal portion of the loop containing the reactive site, and 28.6% identity in the C-terminal portion of the same loop.

Reticolossarcoma simulando doenca reumatologica. / Reticulosarcoma simulating rheumatic disease

Os autores relatam o caso de um paciente de 29 anos que se apresentou com quadro articular e muscular nitido e manifestacoes sistemicas escassas, tendo sido tratado durante varios meses por problema reumatologico. Com a investigacao verificou-se que se tratava de um reticulossarcoma de apresentacao rara, envolvendo primariamente os ossos e nao as estruturas linfoides usuais. Fez-se o diagnostico diferencial com displasia fibroma, metaplasia mieloide agnogenica, doenca de Paget e polimiosite