Suzana G. Leitão

Análise do óleo essencial de folhas de três quimiotipos de Lippia alba (Mill.) N. E. Br. (Verbenaceae) cultivados em condições semelhantes

A composicao do oleo essencial de Lippia alba apresenta variacao quantitativa e qualitativa, levando a separacao em quimiotipos. O trabalho tem como objetivo analisar o oleo essencial de folhas de tres quimiotipos de Lippia alba, provenientes de diferentes regioes do Brasil, cultivados em condicoes semelhantes, a fim de verificar se as diferencas na composicao do oleo devem-se a fatores ambientais ou a variacao genetica infraespecifica e se a floracao influencia o rendimento e a composicao do oleo. Os quimiotipos produtores de citral, carvona e linalol, foram denominados Lippia alba 1, 2 e 3, respectivamente. Os oleos essenciais foram extraidos por hidrodestilacao de folhas e analisados por cromatografia com fase gasosa e cromatografia com fase gasosa acoplada ao espectrometro de massas. O melhor rendimento foi obtido das plantas no estagio vegetativo. A composicao do oleo essencial manteve-se inalterada para os tres quimiotipos apos cultivo em condicoes semelhantes e tambem nao variou qualitativamente durante o crescimento vegetativo e floracao. Os dados obtidos reforcam a ideia que as diferencas na composicao do oleo essencial dos quimiotipos refletem variacoes genotipicas entre as plantas e que a extracao de oleo essencial de L. alba deve ser efetuada na fase de crescimento vegetativo, quando e maior o rendimento do oleo e a porcentagem dos componentes majoritarios.

Screening of Central and South American plant extracts for antimycobacterial activity by the Alamar Blue test

Forty eight ethanolic crude extracts and fractions (hexane, dichloromethane, ethyl acetate and n-butanol) from ten Brazilian plants (Leguminosae, Monimiaceae and Verbenaceae), 1 from Costa Rica (Verbenaceae) and 1 from Argentina (Verbenaceae) were screened for anti-mycobacterium activity against Mycobacterium tuberculosis (ATCC-27294H37Rv), by the Alamar Blue test, at a fixed concentration of 100 µg/mL. Out of the forty eight, seven were active at this concentration, corresponding to Lantana trifolia (hexane and dichloromethane extracts from leaves), Vitex cooperi (methanol:water, 1:1 extract from barks), Lippia lacunosa (hexane and dichloromethane extracts from leaves) and Lippia rotundifolia (hexane and dichloromethane extracts from leaves), all from the Verbenaceae family.

In vitro antiviral effect of flavonoid-rich extracts of Vitex polygama (Verbenaceae) against acyclovir-resistant herpes simplex virus type 1

Extracts and fractions rich in flavonoids from fruits and leaves of Vitex polygama Cham. (Verbenaceae) were tested against acyclovir-resistant herpes simplex virus type 1 (ACV-HSV-1). Both fruit and leaf extracts exhibited a dose-dependent antiviral activity. The extract from the leaves showed intracellular antiviral activity while the extract from the fruits had virucidal effect. A fraction from the ethyl actetate extract of the leaves inhibited virus propagation by blocking HEp-2 cell receptors.

Ethnopharmacological versus random plant selection methods for the evaluation of the antimycobacterial activity

The municipality of Oriximina, Brazil, has 33 quilombola communities in remote areas, endowed with wide experience in the use of medicinal plants. An ethnobotanical survey was carried out in five of these communities. A free-listing method directed for the survey of species locally indicated against Tuberculosis and lung problems was also applied. Data were analyzed by quantitative techniques: saliency index and major use agreement. Thirty four informants related 254 ethnospecies. Among these, 43 were surveyed for possible antimycobacterial activity. As a result of those informations, ten species obtained from the ethnodirected approach (ETHNO) and eighteen species obtained from the random approach (RANDOM) were assayed against Mycobacterium tuberculosis by the microdilution method, using resazurin as an indicator of cell viability. The best results for antimycobacterial activity were obtained of some plants selected by the ethnopharmacological approach (50% ETHNO x 16,7% RANDOM). These results can be even more significant if we consider that the therapeutic success obtained among the quilombola practice is complex, being the use of some plants acting as fortifying agents, depurative, vomitory, purgative and bitter remedy, especially to infectious diseases, of great importance to the communities in the curing or recovering of health as a whole.

Investigation of the antimycobacterial activity of 36 plant extracts from the brazilian Atlantic Forest

Thirty-six plant extracts from the brazilian Atlantic Forest were tested for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv and M. kansasii, using the method REMA in seriate concentrations of 100 to 0.20 µg/mL. Among the thirty six extracts tested, five were active against M. tuberculosis, and three of these extracts also showed activity against M. kansasii. Cytotoxicity test with VERO cells was performed with the five extracts active against M. tuberculosis. Only the extract of Peschiera affinis was identified as non-toxic in the concentration of 100µg/mL.

Separation of Free and Glycosylated Flavonoids from Siparuna guianensis by Gradient and Isocratic CCC

Abstract The separation of free and glycosylated flavonoids from the ethyl acetate extract of the leaves of Siparuna guianensis by step‐gradient and isocratic mode HSCCC is described. The initial fractionation of the extract by a two‐step gradient composed of Hexane∶EtOAc∶MeOH∶H2O 0.6∶4.0∶0.05∶1.0 v/v/v/v (A) and 0.6∶4.0∶0.7∶1.0 (B), reverse phase HSCCC, yielded a sequence of a mixture of diglycosyl flavonoids, followed by a mono‐glycosyl flavonoid and by quercetin, a free flavonoid. The final separation of the more polar and very closely related (structurally and chemically) glycosylated flavonoids, not easily separable by HPLC, was achieved by isocratic normal phase elution, with the solvent system Hexane∶EtOAc∶BuOH∶MeOH∶H2O, 0.6∶4.0∶1.0∶0.05∶1.0. The optimization of the solvent ratios for the gradient and for the isocratic elution is discussed.

Anti-inflammatory and analgesic activity of Bouchea fluminensis

Dried leaves extract from Bouchea fluminensis was assessed in anti-inflammatory (mouse paw edema) and analgesic models (acetic acid-induced writhings and hot plate). Oral pretreatment of animals with a crude mixture (IG) and a purified mixture of ursolic, oleanolic and micromeric acids (IG-59) at doses ranging from 1 to 30 mg/kg, significantly inhibited carrageenin-induced edema formation. At the same doses, IG and IG-59 also exhibited peripheral and central analgesic activity. It seems that B. fluminensis triterpenes develop their analgesic effect through central opioid receptors, due to the observation that naloxone reverted analgesic activity on the hot plate model.

Sterols and sterol glucosides from two Aegiphila species

Abstract The barks of Aegiphila lhotzkyana and A. obducta contain several 24-ethyl- and 24-methylsterols. Among these, stigmasterol, clerosterol, 22-dehydroclerosterol, and the respective β-glucosides were the dominant sterols. The glucoside of 22-dehydroclerosterol is described for the first time. The compositions of the free sterol fractions of both Aegiphila species were found to be very similar to those of several Clerodendrum species of the same family.

Anatomical and chemical analyses of leaf secretory cavities of Rustia formosa (Rubiaceae).

Foliar secretory cavities, commonly called leaf pellucid glands, have been reported in many families of vascular plants. In the Rubiaceae, these structures have only been found in the sister genera Rustia and Tresanthera, which are also anomalous within the family because they have poricidal anthers, and in the distantly related Heterophyllaea. General leaf anatomy, with particular attention to secretory cavities, as well as the chemical analysis of the secreted substances of Rustia formosa, is presented here for the first time. The secretory structures have been found in the lamina between the palisade and spongy parenchymas and in the cortical region of the petiole. The chemical analysis showed that the essential oil secreted is a complex mixture of at least 75 components, mostly of sesquiterpenoid composition. Illustrations of the leaf anatomy, details of the secretory structures of Rustia formosa, a gas chromatogram, and a table of the principal components of the leaf essential oil are included.

Floração, germinação e estaquia em espécies de Lippia L. (Verbenaceae)

Plantas de dez especies de Lippia foram coletadas na Cadeia do Espinhaco, MG, Brasil e cultivadas em canteiros em Juiz de Fora, MG. A epoca de florescimento das especies de Lippia foi observada nos ambientes de origem e em canteiro. A germinacao foi testada com sementes coletadas em ambiente natural. Os materiais estabelecidos ex situ foram avaliados quanto ao enraizamento de estacas. As analises das plantas em ambiente natural e das cultivadas em canteiro evidenciaram que a maioria das especies estudadas apresenta floracao no periodo seco (inverno), enquanto um menor numero, no chuvoso (verao). Uma unica especie floresceu nessas duas estacoes. Em cultivo controlado, o periodo de floracao das especies com floracao caracteristica no verao foi aumentado. Algumas especies germinaram melhor quando recem coletadas enquanto outras quando armazenadas, evidenciando a ocorrencia de perda de viabilidade e de dormencia. O GA3 estimulou a germinacao em algumas especies, enquanto inibiu ou nao apresentou efeitos sobre outras. Sementes de algumas especies germinaram melhor no escuro, enquanto de outras sob luz branca, existindo ainda especies que germinaram tanto na luz quanto no escuro. O enraizamento das estacas das especies nao domesticadas de Lippia foi muito baixo, independente da estacao do ano e da concentracao da auxina. O enraizamento em estacas de L. alba (Mill.) N.E. Br. variou em resposta a epoca de coleta das estacas e quanto ao tipo e a concentracao das auxinas utilizadas. Os resultados do presente trabalho constituem os primeiros relatos envolvendo a reproducao de especies de Lippia endemicas da Cadeia do Espinhaco. Eles indicam a possibilidade de utilizacao das sementes na propagacao das plantas desse genero e tambem evidenciam que a reproducao das plantas das especies nao domesticadas de Lippia atraves de tecnicas convencionais de propagacao assexuada apresenta eficiencia bastante reduzida.