Anti-Trypanosoma, anti-Leishmania and cytotoxic activities of natural products from Psidium brownianum Mart. ex DC. and Psidium guajava var. Pomifera analysed by LC-MS.

Neglected diseases are those that are prevalent in developing countries, even with a rich biodiversity. These diseases still persist because of the lack of scientific studies, government negligence or failures of the public health system. This study aims to identify the composition of extracts and fractions from Psidium brownianum and Psidium guajava through LC-MS, to evaluate its in vitro anti-parasitic and cytotoxic activity against Trypanosoma cruzi, Leishmania brasiliensis and L. infantum epismastigote and promastigote forms, as well as mammalian cells. The results showed the presence of chemical constituents in the two Psidium species as quercetin, myricetin and gallic acid derivatives. The P. brownianum extract and fractions showed low toxicity at all tested concentrations and all samples were effective at the concentration of 1000µg/mL against the parasites, with the extract being the most efficient against the L. infantum promastigote form. The ethanolic extract, and the flavonoid and tannic fractions, from P. guajava showed low toxicity for the fibroblasts. All samples showed effectiveness at the highest concentration tested and the extract was more effective against the promastigote forms tested. The results showed that the species Psidium brownianum and Psidium guajava demonstrated an anti-parasitic activity against the T. cruzi, L. brasiliensis and L. infantum parasite cell lines indicating these species as an alternative therapy given their efficacy in the in vitro assays performed, opening the possibility for new biological studies to further this knowledge through in vivo assays.

Phytochemical Composition, Antifungal and Antioxidant Activity of Duguetia furfuracea A. St.-Hill.

UNLABELLED: Background. Duguetia furfuracea is popular plant used in popular medicine. Hypothesis/Purpose. This claim evaluated the phytochemical composition of the hydroethanolic extract (HEDF), fractions of Duguetia furfuracea, and antioxidant and antifungal activity. Methods. The chemical profile was carried out by HPLC-DAD. The total phenolic contents and flavonoid components were determined by Folin-Ciocalteu and aluminium chloride reaction. The antioxidant activity was measured by scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and ferric reducing ability of plasma (FRAP) methods. The antifungal activity was determined by microdilution assay. RESULTS: HPLC analysis revealed caffeic acid and rutin as major compounds (HEDF), caffeic acid and quercitrin (Mt-OH fraction), and quercitrin and isoquercitrin (Ac-OEt fraction). The highest levels of phenols and total flavonoids were found for Ac-OEt fraction, and the crude extract showed higher in vitro antioxidant potential. The antifungal activity showed synergic effect with fluconazole and EHDF against C. krusei, fluconazole and Mt-OH against C. krusei and C. tropicalis, and Ac-OE and fluconazole against C. albicans. Conclusion. The highest levels of phenols and total flavonoids were marked with antioxidant effect. This is the first report of bioactivity of the synergic effect of HEDF and fractions. More studies would be required to better clarify its mechanism of synergic action.

Avaliação in Vitro da atividade antimicrobiana do carvacrol através dos métodos de contato direto e gasoso / Evaluation In vitro of antimicrobial activity of carvacrol by the direct and gaseous contact methods

Nas últimas décadas, a resistência bacteriana frente aos antimicrobianos se constituiu em um sério problema para a saúde pública, impondo barreiras ao controle de diversas espécies de microrganismos. O carvacrol é um composto fenólico geralmenete encontrado como componente majoritário do óleo essencial de algumas plantas como Origanum vulgare (orégano), Lippia graveolens (Lípia) e Lipia sidoides (alecrim-pimenta). Estudos demonstram a atividade antibacteriana do orégano, possivelmente devido ao carvacrol. Para avaliar a ação antimicrobiana desse composto, foram utilizadas linhagens padrão bacterianas (Staphylococcus aureus ATCC25923 e Pseudomonasa aeruginosa ATCC15442) e fúngicas (Candida albicans ICB12, C. krusei ATCC6258 e C. tropicalis ATCC13803). Os métodos de microdiluição em caldo e de contato gasoso foram utilizados para determinar a concentração inibitória mínima (CIM) e a dose inibitória mínima (DIM) respectivamente, bem como a atividade moduladora da ação antibiótica através de ambos os métodos. O carvacrol, combinado em concentrações subinibitórias com as drogas antimicrobianas apresentou resultados relevantes frente às cepas de Staphylococcus aureus e Candida albicans, por tanto este estudo permitiu comprovar a atividade moduladora do carvacrol.

In the last decades, the bacterial resistance to antimicrobials becomes a serious problem of public health, creating several difficulties to control several microrganisms with nosocomial interest. The carvacrol, the main phenol compound of many plants as Origanum vulgare, Lippia graveolens and Lipia sidoides. Studies demonstrated and intensive antibacterial activity of O. vulgare, probably due the carvacrol. To evaluate the antimicrobial activity of this compound, were assayed microbial strains of Staphylococcus aureus ATCC25923, Pseudomonas eruginosa ATCC15442, Candida albicans ICB12, C. krusei ATCC6258 and C. tropicalis ATCC 13803. Using the microdilution and the gaseous contact method, were determined the minimum inhibitory concentration (MIC) and the minimum inhibitory dose (DIM), respectively as well as the modulatory activity with both methods. The carvacrol, used in subinhibitory concentrations associated with antimicrobial drugs demonstrated an interesting modulatory activity against Staphylococcus aureus and Candida albicans strains, indicating the antimicrobial and modulatory activity of this compound.