Amanda Luana Forbrig Froeder

Antimicrobial and cytotoxic activities of leaves, twigs and stem bark of Scutia buxifolia Reissek

The antimicrobial and cytotoxic activities of the dichloromethane, ethyl acetate and butanolic fractions from the leaves, twigs and stem bark of Scutia buxifolia were evaluated using the broth microdilution method and the brine shrimp lethality method, respectively. Phytochemical analysis was performed by thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The antimicrobial results demonstrated that the strongest effect occurred with the butanol fraction from the twigs and the ethyl acetate fraction from the stem bark against Saccharomyces cerevisiae (minimal inhibitory concentration; MIC = 62.5 µg mL−1), whereas the ethyl acetate and butanolic fractions from the twigs and stem bark were effective against Pseudomonas aeruginosa and Staphylococcus aureus, with MIC values ranging from 125 to 500 µg mL−1. LD50 values varied from 50.00 ± 0.22 to 82.23 ± 0.34 µg mL−1. Quercetin, quercitrin, isoquercitrin and rutin were identified by HPLC and may be partially responsible for the antimicrobial activities observed. This study reports for the first time the antimicrobial and cytotoxic activities of S. buxifolia leaves, twigs and stem bark.

The antinociceptive and anti-inflammatory effects of the crude extract of Jatropha isabellei in a rat gout model

ETHNOPHARMACOLOGICAL RELEVANCE Jatropha isabellei Müll Arg. (Euphorbiaceae) is a medicinal plant that has been used in South American folk medicine for the treatment of arthritic diseases, particularly gout. AIM OF THE STUDY This study was designed to verify the antinociceptive, anti-inflammatory and hypouricemic potential of Jatropha isabellei. MATERIALS AND METHODS Rats were orally administered with the crude extract (100-300 mg/kg) or a fraction that is rich in alkaloids (0.15 mg/kg) of Jatropha isabellei. An intra-articular (i.a.) injection of 50 μl of monosodium urate (MSU) crystals (1.25mg/site) was used to generate the gout model to assess the effect of the treatment on nociception (thermal and mechanical hyperalgesia) and inflammation (oedema and neutrophil infiltration). The effect of Jatropha isabellei on the serum levels of uric acid was evaluated in a model of hyperuricaemia induced by the intraperitoneal injection of potassium oxonate (250 mg/kg). The side effects were analysed using an open-field test, gastric lesion assessment and by measuring the levels of the ALT and AST enzymes. RESULTS Our study demonstrated that the crude extract of Jatropha isabellei and a fraction rich in alkaloids were able to prevent the thermal hyperalgesia, mechanical allodynia, oedema and neutrophil infiltration induced by intra-articular MSU injection in rats. On the other hand, treatment with Jatropha isabellei did not alter the uric acid levels increased by potassium oxonate in the hyperuricaemia model. In addition, Jatropha isabellei did not induce gastric lesions or liver damage and did not alter spontaneous locomotor activity. CONCLUSION The crude extract of Jatropha isabellei and its fraction rich in alkaloid presents antinociceptive and anti-inflammatory effects in a rat gout model, similar to that observed after treatment with colchicine, supporting the traditional use of this plant in gouty patients.

Centella asiatica and Its Fractions Reduces Lipid Peroxidation Induced by Quinolinic Acid and Sodium Nitroprusside in Rat Brain Regions.

Oxidative stress has been implicated in several pathologies including neurological disorders. Centella asiatica is a popular medicinal plant which has long been used to treat neurological disturbances in Ayurvedic medicine. In the present study, we quantified of compounds by high performance liquid chromatography (HPLC) and examined the phenolic content of infusion, ethyl acetate, n-butanolic and dichloromethane fractions. Furthermore, we analyzed the ability of the extracts from C. asiatica to scavenge the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) radical as well as total antioxidant activity through the reduction of molybdenum (VI) (Mo6+) to molybdenum (V) (Mo5+). Finally, we examined the antioxidant effect of extracts against oxidant agents, quinolinic acid (QA) and sodium nitroprusside (SNP), on homogenates of different brain regions (cerebral cortex, striatum and hippocampus). The HPLC analysis revealed that flavonoids, triterpene glycoside, tannins, phenolic acids were present in the extracts of C. asiatica and also the phenolic content assay demonstrated that ethyl acetate fraction is rich in these compounds. Besides, the ethyl acetate fraction presented the highest antioxidant effect by decreasing the lipid peroxidation in brain regions induced by QA. On the other hand, when the pro-oxidant agent was SNP, the potency of infusion, ethyl acetate and dichloromethane fractions was equivalent. Ethyl acetate fraction from C. asiatica also protected against thiol oxidation induced by SNP and QA. Thus, the therapeutic potential of C. asiatica in neurological diseases could be associated to its antioxidant activity.

Antioxidant capacity, antimicrobial activity and triterpenes isolated from Jatropha isabellei Müll Arg.

Jatropha isabellei Müll Arg. belongs to the family Euphorbiaceae. The antioxidant capacity of this plant was evaluated by the DPPH method and inhibition of thiobarbituric acid reactive substances (TBARS). Ethyl acetate fraction demonstrated the best antioxidant capacity against the DPPH free radical and its profile was similar to ascorbic acid. This fraction also presented the best results of phenolics, flavonoids and condensed tannins, showing a positive relation between the phenolic content and antioxidant activity. All fractions and the crude extract were able to inhibit significantly the TBARS production induced by Fe(II) for the two tested concentrations, reaching the basal levels. In this test, ethyl acetate and dichloromethane fraction showed good values for inhibitory concentration. The dichloromethane fraction showed the best results against the fungi Sporothrix schenckii and Fusarium proliferatum and the bacterium of Micrococcus genus. This fraction allowed the isolation of acetil aleuritolic acid and a mixture of sitosterol 3-O-β-D-glucoside and stigmasterol, described for the first time in this species.

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.

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 EM EXTRATO LIOFILIZADO DE VIOLA TRICOLOR L.

A quantidade de flavonoides em plantas medicinais tem sido pesquisada em diversas especies, tanto no Brasil quanto em outros paises. O objetivo deste estudo foi realizar o doseamento dos flavonoides presentes no do extrato bruto das flores de Viola tricolor L. atraves de metodo descrito por Woisky e Salatino (1998) com pequenas modificacoes. A quantidade de flavonoides no extrato bruto foi de 111,17 miligramas de de rutina por grama de extrato bruto, demonstrando que esta especie e promissora para novos estudos que possam comprovar seu uso popular.

COMPOSTOS ISOLADOS DE JATROPHA ISABELLI (MÜELL ARG) COMO ATIVIDADE GASTROPROTETORA

As plantas medicinais sao importantes para a pesquisa farmacologica e para o desenvolvimento de farmacos nao somente quando seus constituintes sao usados diretamente como agentes terapeuticos, mas tambem como materias-primas isoladas para a sintese ou modelo de compostos farmacologicamente ativos. No entanto, apenas pequena parte das plantas foram estudadas e tiveram suas acoes farmacologicas conhecidas. A fim de mostrar o potencial de Jatropha isabelli Muell Arg (Euphorbiaceae) para o desenvolvimento de um medicamento a partir de seus ativos isolados, as atividades biologicas ja comprovadas da planta sao apresentadas. Palavras-chave: Jatropha isabelli, Euphorbiaceae, yagua rova.