Marina Zadra

Chemical composition and antioxidant activity of the essential oil of Tabernaemontana catharinensis A. DC. leaves

The essential oils obtained by hydrodistillation from the leaves of Tabernaemontana catharinensis had their composition analysed by GC–MS. A total of 18 substances were identified, consisting of a complex mixture of sesquiterpenes (83.52%), monoterpenes (5.46%) and triterpenes (4.56%). The main components in the oil were β-caryophyllene (56.87%), α-cadinol (12.52%), 8S,13-cedran-diol (5.41%), α-terpineol (3.99%), β-eudesmol (2.54%), caryophyllene oxide (2.51%) and ethyl iso-allocholate (2.03%) along with β-cubebene, γ-cadinene, cubenol, 1,8-cineol, o-cymene, curcumenol, spathulenol, friedeline and β-sitosterol as minor constituents. An antioxidant property was tested with the oil obtained by means of 1,1-diphenyl-2-picrylhydrazyl assay; the oil presented interesting radical scavenging activity. To the best of our knowledge, this is the first study of the composition and antioxidant activity of essential oil from the T. catharinensis collected from Brazil.

Antioxidant Activity and Phytochemical Composition of the Leaves of Solanum guaraniticum A. St.-Hil

Solanum guaraniticum is a shrub belonging to the Solanaceae family popularly known in Brazil as jurubeba or false-jurubeba. The aim of this study was to evaluate the antioxidant activity of crude extract and chloroform, ethyl acetate and n-butanol fractions from its leaves, verifying the ability to remove reactive species and identify and quantify phenolic compounds. The ethyl acetate fraction showed the highest amount of total polyphenols (546.57 ± 2.35 mg gallic acid equivalent/g) and the lowest IC50 (9.11 ± 0.75 µg/mL) by the DPPH method. Furthermore, the chloroform fraction presented the highest content of flavonoids (75.73 ± 0.34 mg rutin equivalents/g), tannins (56.03 ± 0.68 mg catechin equivalents/g) and alkaloids (10.79 ± 0.06 mg/g). This fraction was effective in the scavenging of reactive species by 2′,7′-dichlorofluorescein diacetate assay, in addition to completely reducing protein carbonyl content and reducing lipid peroxidation at basal levels even at low concentrations. Chlorogenic, caffeic and rosmarinic acids were identified and quantified by HPLC/DAD. These results show that S. guaraniticum is rich in phenolic compounds and has potential as an antioxidant.

Antimicrobial activity of Scutia buxifolia against the honeybee pathogen Paenibacillus larvae

The honeybee disease American foulbrood (AFB) is a serious problem since its causative agent (Paenibacillus larvae) has become increasingly resistant to conventional antibiotics. One of the feasible alternative treatments being used for control of this disease are plants extracts. The aim of the present work was to evaluate the effect of crude extract and fractions of Scutia buxifolia against six Paenibacillus species, including P. larvae, and its potential use for the control of AFB. In vitro activity of S. buxifolia samples against Paenibacillus species were evaluated by the disk diffusion and microdilution methods, and the minimal inhibitory concentration (MIC) were also determined. All Paenibacillus species were sensitive to crude extract and fractions of S. buxifolia. The dichloromethane (DC) fraction showed the better MIC (1.56 mg/mL), followed by ethyl acetate (EtAc) (6.25 mg/mL), n-butanol (BuOH) (25 mg/mL) and Crude extract (CE) (50 mg/mL). Toxic effect of S. buxifolia crude extracts and fractions against bees were also evaluated by the spraying application method of the same concentrations of MICs. The samples tested showed no toxic effects for the bees after 15 days of observation. These results are first time described for this species and showed that S. buxifolia presented a important activity against Paenibacillus species and proved to be a natural alternative for the prevention/control of AFB.

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.

Analysis of rutin in the extract and gel of Viola tricolor.

Heartsease, also known as wild pansy (Viola tricolor L.), contains considerable amounts of polyphenols: 109.32 ± 1.29 mg of Gallic acid equivalent/g of extract. This study investigates their phytoconstituents and antioxidant capacity and validates a method for the quantification of rutin in the crude extract of the flowers of V. tricolor and in the extract incorporated in gel. Much better antioxidant capacity was found for the extract [inhibition concentration (IC50) of 16.00 ± 0.78 µg/mL] than the standard ascorbic acid (IC50 of 16.57 ± 0.95 µg/mL); these excellent results may be attributable to the amounts of polyphenols, flavonoids and condensed tannins. The high-performance liquid chromatography method for the quantification of rutin in the extract and gel was linear, sensitive, precise, specific, accurate and robust. This validated method can be used to control the quality of the extract and the gel.

Composition and antioxidant capacity of the essential oil of leaves of Vitex megapotamica (Sprengel) Moldenke

This study is designed to examine the chemical composition and antioxidant activity of the essential oil of Vitex megapotamica. Gas chromatography–mass spectrometry analysis resulted in the detection of 27 components, representing 92.36% of the total oil composition. The main components in the oil were butylated hydroxytoluene (BHT) (34.17%), phytol (12.66%), α-caryophyllene (11.84%), δ-elemene (10.65%), β-caryophyllene (7.82%), γ-elemene (4.24%) and germacrene D (2.82%). The antioxidant activity of the oil was evaluated in terms of their free-radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl. The oil showed percentage inhibition of 35.62% and 75.25% at concentrations of 76 and 101.6 mg mL−1, respectively. BHT (36.30%) was also determined by HPLC-DAD in the hexane fraction from the leaves. To the best of our knowledge, this is the first study of the composition and antioxidant activity of the essential oil of the species V. megapotamica.

ANÁLISE FITOQUÍMICA DAS FOLHAS DE VITEX MEGAPOTAMICA (SPRENGEL) MOLDENKE

A especie Vitex megapotamica (Sprengel) Moldenke, usualmente conhecida como taruma, pertence a familia Verbenaceae a qual compreende cerca de 100 generos distribuidos nas regioes tropicais de todo o mundo. Esta especie tem sido usada na medicina tradicional principalmente para hemorroidas, depurativa do sangue, hipertensao arterial, antiinflamatoria, dentre outras. O presente trabalho teve por objetivo a realizacao da triagem farmacognostica de extratos de Vitex megapotamica . Os resultados da analise fitoquimica indicaram a presenca de heterosideos antociânicos, fenois e taninos, catequinas, flavonois, flavanonas, flavanonois e xantonas, esteroides e triterpenoides (esteroides livres), heterosideos cardioativos, fenois com posicao orto e meta livres, fenois com a posicao para livre, cumarinas, acidos orgânicos e fenois.

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.