Bianca Vargas Belke

Antiinflammatory effects of Viola tricolor gel in a model of sunburn in rats and the gel stability study.

ETHNOPHARMACOLOGICAL RELEVANCE Viola tricolor, popularly known as heartsease has been empirically used in several skin disorders, including burns. AIM OF THE STUDY The objective of this study was investigate the antinociceptive and antiinflammatory effect of a gel containing extract of Viola tricolor flowers on thermal burn induced by UVB irradiation and to perform gel stability study. METHODS The antinociceptive and antiinflammatory effect were evaluated by static and dynamic mechanical allodynia model, paw edema, and neutrophilic cell infiltration. Metabolites compounds were quantified by HPLC. The gel stability study was performed analyzing organoleptical aspects, besides pH, viscosity, and quantification of rutin by HPLC. RESULTS In the results were evidenced changes in threshold in statical and dynamic mechanical allodynia (I(max)=100 ± 10% and 49 ± 10%, respectively), paw edema (I(max)=61 ± 6%), and myeloperoxidase activity (I(max)=89 ± 5%). Such effects may be attributed, in part, to rutin, salicylic and chlorogenic acids, and others compounds found in this species. No important changes were detected in the stability study, in all aspects analyzed in temperature below 25 °C. CONCLUSION These findings suggest that Viola tricolor gel has an antinociceptive and antiinflammatory effect in the ultraviolet-B-induced burn, since maintain the temperature below 25 °C.

In vitro antimicrobial and antimycobacterial activity and HPLC–DAD screening of phenolics from Chenopodium ambrosioides L.

The main objective of this study was to demonstrate the antimicrobial potential of the crude extract and fractions of Chenopodium ambrosioides L., popularly known as Santa-Maria herb, against microorganisms of clinical interest by the microdilution technique, and also to show the chromatographic profile of the phenolic compounds in the species. The Phytochemical screening revealed the presence of cardiotonic, anthraquinone, alkaloids, tannins and flavonoids. The analysis by HPLC–DAD revealed the presence of rutin in the crude extract (12.5 ± 0.20 mg/g), ethyl acetate (16.5 ± 0.37 mg/g) and n-butanol (8.85 ± 0.11 mg/g), whereas quercetin and chrysin were quantified in chloroform fraction (1.95 ± 0.04 and 1.04 ± 0.01 mg/g), respectively. The most promising results were obtained with the ethyl acetate fraction, which inhibited a greater number of microorganisms and presented the lowest values of MIC against Staphylococcus aureus and Enterococcus faecalis (MIC = 0.42 mg/mL), Pseudomonas aeruginosa (MIC = 34.37 mg/mL), Paenibacillus apiarus (MIC = 4.29 mg/mL) and Paenibacillus thiaminolyticus (MIC = 4.29 mg/mL). Considering mycobacterial inhibition, the best results were obtained by chloroform fraction against M. tuberculosis, M. smegmatis, and M. avium (MIC ranging from 156.25 to 625 μg/mL). This study proves, in part, that the popular use of C. ambrosioides L. can be an effective and sustainable alternative for the prevention and treatment of diseases caused by various infectious agents.

Scutia buxifolia Reissek essential oil: in vitro antioxidant and antimicrobial activities

The volatile oil from the stem bark of Scutia buxifolia (Rhamnaceae) has been obtained by hydrodistillation and analyzed by GC-MS. Twenty-one components were identified representing 99.93 % of the total oil composition, spathulenol (35.87%), β-cubebene (17.26%), germacrene D (6.43%), linalool (5.19%), carvacrol (4.05%) were the main components of S. buxifolia essential oil. Antioxidant and antimicrobial properties of the essential oil were evaluated by free radical scavenging (DPPH) assay and micro broth dilution method, respectively. S. buxifolia essential oil presented interesting radical scavenging activity (IC50 = 15.03 ± 0.11 µg/mL). The antibacterial assay showed that S. buxifolia stem bark essential oil was moderately active against the Staphylococcus aureus and Micrococcus sp. (MIC = 500 µg/mL) and Escherichia coli (250 µg/mL). To the best of our knowledge, this is the first study on the composition, antioxidant and antimicrobial activities of essential oil from the S. buxifolia collected from Brazil.

Antioxidant Activity and Phytochemical Composition of Solanum corymbiflorum Fractions (Leaves and Fruits)

The antioxidant activity and phenolic compounds of the chloroform (CHCl3), ethyl acetate (AcOEt) and n-butanol (n-BuOH) fractions from Solanum corymbiflorum leaves and fruits were evaluated. The AcOEt fraction of the leaves presented the highest content of total polyphenols (114.00 mg GAE/g) and the best antioxidant capacity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) test (IC50 = 31.90 µg/mL). For the fruits, the same fraction exhibited the highest content of phenolics (99.77 mg GAE/g) and best results in the DPPH test (IC50 = 141.47 µg/mL). In relation to 2′,7′-dichlorofluorescein diacetate (DCFH-DA) and thiobarbituric acid reactive substances (TBARS) assays, the CHCl3 fraction of leaves and fruits showed better results than the other samples analyzed. Besides of the phenolic compounds, the alkaloids contributed in the activity. Rutin, chlorogenic and caffeic acids quantified by HPLC are some of phenolic compounds responsible by this activity S. corymbiflorum can be a promising source of natural antioxidants. However, more in vivo studies are required to stimulate the consumption and its other potentialities.

DOSEAMENTO DE FLAVONÓIDES NOS RAMOS DE TABERNAEMONTANA CATHARINENSIS A. DC.

O objetivo desse trabalho foi realizar o doseamento de flavonoides do extrato bruto e fracoes dos ramos de Tabernaemontana catharinensis. Os ramos da planta foram coletadas no municipio de Sao miguel (RS) em Janeiro de 2009. O extrato aquoso foi obtido atraves de maceracao com etanol (70%). Apos foi eliminado o etanol, o extrato aquoso foi fracionado com solventes: cloroformio, acetato de etila e n-butanol e levados a secura. O dosemaneto de flavonoides foi realizado segundo o metodo de Woisky e Salatino (1998) com pequenas modificacoes, o qual utiliza o reagente AlCl 2% leitura em 420 nm. O resultados mostraram que a fracao cloroformica seguida das fracoes acetato de etila e butanolica obtiveram maior teor de flavonoides. Esta especie e promissora para novos estudos que comprovem sua atividade antioxidante e sua acao terapeutica.

QUANTIFICAÇÃO DE FLAVONÓIDES NAS RAIZES DE URERA BACCIFERA GAUDICH (URTICACEAE)

O objetivo desse trabalho foi quantificar flavonoides nas raizes de Urera baccifera. As raizes da planta foram coletadas no municipio de Sao Francisco de Assis (RS) em Maio de 2010. O extrato bruto foi obtido atraves demaceracao com etanol (70%). Apos a eliminacao do etanol, o extrato foi fracionado com cloroformio, acetato de etilae n-butanol e levados a secura. As amostras foram testadas frente a uma solucao de cloreto de aluminio 2%, segundo Woisky e Salatino (1998). Para quantificacao utilizou-se uma curva com o padrao quercetina e os resultados foram expressos em mg de planta/g de equivalentes de quercetina, sendo eles: extrato bruto:16,43 mg/g EQ; fracao cloroformio:76,78 mg/g EQ; fracao acetato de etila: 15,38 mg/g EQ e fracao n-butanol: 9,24mg/g EQ. Esses resultadosindicaram uma boa concentracao de flavonoides na fracao cloroformio, o que indica que a planta e promissora para mais estudos que aprofundem os conhecimentos.