Antidiarrheal activity of extracts from Maytenus gonoclada and inhibition of Dengue virus by lupeol

ABSTRACT Diarrhea is an infectious disease caused by bacterial, virus, or protozoan, and dengue is caused by virus, included among the neglected diseases in several underdeveloped and developing countries, with an urgent demand for new drugs. Considering the antidiarrheal potential of species of Maytenus genus, a phytochemical investigation followed by antibacterial activity test with extracts of branches and heartwood and bark of roots from Maytenus gonoclada were conducted. Moreover, due the frequency of isolation of lupeol from Maytenus genus the antiviral activity against Dengue virus and cytotoxicity of lupeol and its complex with β-cyclodextrins were also tested. The results indicated the bioactivity of ethyl acetate extract from branches and ethanol extract from heartwood of roots of M. gonoclada against diarrheagenic bacteria. The lupeol showed potent activity against Dengue virus and low cytotoxicity in LLC-MK2 cells, but its complex with β-cyclodextrin was inactive. Considering the importance of novel and selective antiviral drug candidates the results seem to be promising.

Psychotria viridis: Chemical constituents from leaves and biological properties

ABSTRACT The phytochemical study of hexane, chloroform and methanol extracts from leaves of Psychotria viridis resulted in the identification of: the pentacyclic triterpenes, ursolic and oleanolic acid; the steroids, 24-methylene-cycloartanol, stigmasterol and β-sitosterol; the glycosylated steroids 3-O-β-D-glucosyl-β-sitosterol and 3-O-β-D-glucosyl-stigmasterol; a polyunsaturated triterpene, squalene; the esters of glycerol, 1-palmitoylglycerol and triacylglycerol; a mixture of long chain hydrocarbons; the aldehyde nonacosanal; the long chain fat acids hentriacontanoic, hexadecanoic and heptadenoic acid; the ester methyl heptadecanoate; the 4-methyl-epi-quinate and two indole alkaloids, N,N-dimethyltryptamine (DMT) and N-methyltryptamine. The chemical structures were determined by means of spectroscopic (IR, 1H and 13C NMR, HSQC, HMBC and NOESY) and spectrometric (CG-MS and LCMS-ESI-ITTOF) methods. The study of biologic properties of P. viridis consisted in the evaluation of the acetylcholinesterase inhibition and cytotoxic activities. The hexane, chloroform, ethyl acetate and methanol extracts, the substances 24-methylene-cycloartanol, DMT and a mixture of 3-O-β-D-glucosyl-β-sitosterol and 3-O-β-D-glucosyl-stigmasterol showed cholinesterase inhibiting activity. This activity induced by chloroform and ethyl acetate extracts was higher than 90%. The methanol and ethyl acetate extracts inhibit the growth and/or induce the death of the tumor cells strains B16F10 and 4T1, without damaging the integrity of the normal cells BHK and CHO. DMT also demonstrated a marked activity against tumor cell strains B16F10 and 4T1.

Hydroalcoholic extracts of Vellozia squamata: study of its nanoemulsions for pharmaceutical or cosmetic applications

Some species of plants are notable for the wide range of biologically active constituents in their tissues. Chemical and pharmacological studies of Vellozia squamata Pohl, Velloziaceae, popularly known in Brasil as "canela-de-ema" are scarce, but showed the presence of di-and triterpenoid that may be of scientific interest. In the present study the hydroalcoholic extracts from leafs and stems of V. squamata were submitted to phytochemical prospection to identify the principal groups of constituents, and the antioxidant activity was determined by DPPH method. The hydroethanolic extracts presented higher antioxidant activity. Thus, nanoemulsion formulations were prepared using the method of phase inversion. Accelerated stability tests, such as heat stress and centrifugation were made, and physical and chemical properties of the nanoemulsions were established. Stable formulations were obtained from both extracts from leafs and stems. By the results was possible to establish the potential application of hydroalcoholic extracts from V. squamata in development of products with antioxidant properties and demonstrate a promising pharmaceutical product.

Antioxidant activity of Maytenus imbricata Mart., Celastraceae / Atividade antioxidante de Maytenus imbricata Mart., Celastraceae

The free radical scavenging activity (FRS) using 2,2-diphenyl-1-picrylhydrazyl (DPPH), the reducer power and the total phenolic concentration of extracts and compounds isolated from leaves, branches and roots of Maytenus imbricata Mart. (Celastraceae) were evaluated. Some extracts, a mixture of phenolic compounds (MPC) and epicatechin showed higher RP and FRS (DPPH) activities in comparison with the standard butylhydroxyanisole (BHA) and galic acid (GA) used in assays. The ethyl acetate extract from leaves showed higher total phenolic content and also higher RP and FRS (DPPH) than the other extracts. These facts indicate that there are some relations between phenolic concentration in the extract and the antioxidant activity and the reducer power. The solvent used in the extraction process influences the chemical composition of the extracts and consequently its antioxidant and reducer power activities.

A atividade antioxidante, poder redutor (RP) e a atividade coletora de radicais livres (FRS) usando 2,2-difenil-1-picrilhidrazil (DPPH), e a concentração de substâncias fenólicas totais dos extratos e substâncias isoladas das folhas, caules e raízes de Maytenus imbricata Mart. (Celastraceae) foram avaliados. Alguns extratos, a mistura de compostos fenólicos e epicatequina mostraram alto poder redutor e atividade antioxidante (DPPH) em comparação com o padrão butilhidroxianisol (BHA) e ácido gálhico (GA) utilizados no ensaio. O extrato acetato de etila das folhas mosraram alto teor de substâncias fenólicas e alto poder redutor e atividade antioxidante em relação aos outros extratos. Este fato indica haver alguma relação entre a concentração de substâncias fenólicas e o poder redutor. O solvente usado no processo de extração influencia a composição química dos extratos e, consequentemente, as atividades redutoras e antioxidantes.

Evaluation of antibacterial activity of "Mangabarana" Austroplenckia populnea Reissek (Celastraceae) / Avaliação da atividade antibacteriana de "Mangabarana" Austroplenckia populnea Reissek (Celastraceae)

Austroplenckia populnea (Mangabarana) is popularly used by people from Minas Gerais, Brazil for dysenteries diseases treatment. Antitumor and antiulcer activities were also attributed to this plant. Extracts obtained using solvents of different polarities and pentacyclic triterpenes (PCTTs) isolated from these extracts through phytochemical methods were submitted to antibacterial assays. The results showed the existence of this activity and open perspectives for news studies with other organic compounds isolated from this plant.

Austroplenckia populnea (Mangabarana) é popularmente utilizada em Minas Gerais, Brasil, para o tratamento de disenterias. A ela também são atribuídas propriedades antitumoral e antiúlcera. Extratos de partes desta planta obtidos com solventes de diferentes polaridades e triterpenos pentacíclicos (TTPCs) isolados destes, por métodos fitoquímicos foram submetidos a testes de atividade antibacteriana. Os resultados mostraram a existência desta atividade e abriram perspectivas para a continuidade dos estudos com outros compostos orgânicos isolados desta planta.