Cristiane Bezerra da Silva

Levantamento etnobotânico e caracterização de plantas medicinais em fragmentos florestais de Dourados-MS

Objetivou-se, neste estudo, coletar e identificar especies nativas consideradas medicinais em dois fragmentos florestais no municipio de Dourados-MS. Foram identificadas 37 especies distribuidas em 28 familias as quais foram indicadas pelos mateiros da regiao por serem utilizadas pela populacao como alternativa medicinal. Das familias identificadas, as que apresentaram maior numero de especies foram Piperaceae (10,8%), Moraceae (8,1%), Smilaceae (8,1%), Myrtaceae (5,4%) e Rubiacee (5,4%). O levantamento etnobotânico indicou 45 diferentes usos medicinais para as especies e as partes mais utilizadas para o preparo de remedios sao as folhas e cascas, sendo que as doencas para as quais houve maior numero de indicacoes foram reumatismo, disenteria, diabetes, febres, tosses e cicatrizacoes.

Composição química e atividade alelopática do óleo volátil de Hydrocotyle bonariensis Lam (araliaceae)

Os oleos essenciais sao liquidos aromaticos obtidos de materiais vegetais (flores, folhas, ramos, sementes, ervas, madeira, frutos, raizes e cascas), sendo constituidos por misturas complexas, dentre outras, de terpenoides que podem conter ate 100 ou mais compostos orgânicos. Os terpenos encontrados com maior frequencia nos oleos essenciais sao os monoterpenos, sesquiterpenos e com menor frequ-encia os diterpenos. Seus constituintes terpenicos podem apresentar diversas funcoes orgânicas, como alcoois, cetonas, eteres, esteres e aldeidos. Os terpenos possuem, tambem, diversas funcoes nas plantas atuando como fitoalexinas, repelentes de insetos, agentes de atracao polinica, agentes de defesa contra herbivoros, feromonios, hormonios vegetais, moleculas de sinalizacao e aleloquimicos.

Phytotoxic and antioxidant activity of seven native fruits of Brazil

We investigated antioxidant capacity, phenolic content and phytotoxic effects in seven species of fruit native to Brazil: Acrocomia aculeata, Hymenaea stigonocarpa, Tamarindus indica, Byrsonima intermedia, Psidium firmum, Myrciaria cauliflora and Ficus obtusifolia. Phytotoxic effects were assessed from crude ethanol extracts and semipurified fractions. In four of the seven fruits, total phenolic content, as determined by Folin-Ciocalteu assay, was higher in the peel than in the pulp. We found that total phenolic content correlated significantly with antioxidant capacity. High-performance liquid chromatography with diode array detection revealed the presence of the flavonoids quercetin and rutin in some fruits. We also evaluated the allelopathic effects of the crude ethanol extract and semipurified fractions. In most of the essays, the ethyl acetate fractions showed the highest level of activity.

Chemical Composition and Biological Activities of Leaves Essential Oil From Schinus molle (Anacardiaceae)

Abstract The essential oil of Schinus molle (Anacardiaceae) obtained by hydrodistillation from the aerial parts, was analyzed by gas chromatography (GC), GC-mass spectrometry (MS) and nuclear magnetic resonance (NMR). The oil contains 69.1 % of sesquiterpenes and 20 % of monoterpenes. The most abundant essential oil components were 1,8-cineole (7.6 %), terpin-4-ol (6.1 %), epi-a-cadinol (27.3 %), caryophyllene oxide (10.5 %), y-cadinene (9.1 %), spathulenol (8.6 %), 1,10-di-epi-cubenol (4.4 %) and 7-epi-a-eudesmol (2.3 %). The leaf essential oil showed pronounced in-vitro cytotoxic activity against K562 (0.89 μg/mL) and NCI-ADR/RES (3.40 μg/mL) human tumor cell lines. The antimicrobial, antioxidant and allelophathic activities of essential oil were also evaluated.

Effect of Donepezil, Tacrine, Galantamine and Rivastigmine on Acetylcholinesterase Inhibition in Dugesia tigrina

Dugesia tigrina is a non-parasitic platyhelminth, which has been recently utilized in pharmacological models, regarding the nervous system, as it presents a wide sensitivity to drugs. Our trials aimed to propose a model for an in vivo screening of substances with inhibitory activity of the enzyme acetylcholinesterase. Trials were performed with four drugs commercialized in Brazil: donepezil, tacrine, galantamine and rivastigmine, utilized in the control of Alzheimer’s disease, to inhibit the activity of acetylcholinesterase. We tested five concentrations of the drugs, with an exposure of 24 h, and the mortality and the inhibition of acetylcholinesterase planarian seizure-like activity (pSLA) and planarian locomotor velocity (pLMV) were measured. Galantamine showed high anticholinesterasic activity when compared to the other drugs, with a reduction of 0.05 μmol·min−1 and 63% of convulsant activity, presenting screw-like movement and hypokinesia, with pLMV of 65 crossed lines during 5 min. Our results showed for the first time the anticholinesterasic and convulsant effect, in addition to the decrease in locomotion induced by those drugs in a model of invertebrates. The experimental model proposed is simple and low cost and could be utilized in the screening of substances with anticholinesterasic action.

Effects of volatile oils of the Microlobius foetidus on trypsin, chymotrypsin and acetylcholinesterase activities in Aedes aegypti (Diptera: Culicidae)

Volatile oils of Microlobius foetidus were used for the evaluation of mortality, trypsin, chymotrypsin and acetylcholine inhibition and Aedes aegypti morphology. Bioassays were made with different concentrations (25, 50 and 100 μg/ml) and alterations in the gut of 4th stage larvae were observed. Volatile oils affected larvae in all stages, with 100% mortality for the 100 μg/ml concentration (LD50 >33.02). The acute toxic unit (2.7 μg/ml), chronic toxic unit (32.68 μg/ml) and toxic load (2.7 μg/ml) confirm the sensibility of the 4th stage larvae. These larvae and 3rd presented a lesser trypsin (0.176 μmol/min), chymotrypsin (0.110 μmol/min) and acetylcholinesterase (0.172 μmol/min) synthesis. Larvae of the 4th stage also had their internal morphology observed, and the main alterations were discontinuity of the peritrophic epithelium, thickening of the peritrophic membrane, decrease/increase of the subjacent epithelium and decrease of endoperitrophic space were observed in the mid gut. The results show the repellent activity of the volatile oils of M. foetidus, with a retardation of overall growth, that are associated with the inhibition of the trypsin and chymotrypsin synthesis. Mortality and enzymatic inhibition in all developmental stages confirm the insecticide potential of M. foetidus. Key words: Dengue fever, digestive system, biological control agents, natural products.

Atividade fitotóxica de Croton doctoris S. Moore

The aim of this study was to verify the phytotoxic effect of the crude ethanol extract and semipurified fractions from the stem and leaves of Croton doctoris on the germination, growth and cell division of roots cells of lettuce (Lactuca sativa) and onion (Allium cepa), in the laboratory. The bioassays was conducted in using completely randomized design, with four concentrations (0, 250, 500, 1.000mg L-1) and four replications. The crude extract and the fractions from the stem and leaves inhibited germination and seedling growth of lettuce and onion, with greater phytotoxic effect observed in the ethyl acetate fraction (EAF) from the stems and leaves that significantly affected the growth and mitotic index of root cells of lettuce and onions. With these results it appears that C. doctoris contains substances capable of influencing the germination, growth and cell division of the species studied.