Leishmanicidal activity of carvacrol-rich essential oil from Lippia sidoides Cham

Leishamaniasis is a disease that affects more than 2 million people worldwide, whose causative agent is Leishmania spp. The current therapy for leishmaniasis is far from satisfactory. All available drugs, including pentavalent antimony, require parenteral administration and are potentially toxic. Moreover, an increase in clinical resistance to these drugs has been reported. In this scenario, plant essential oils used traditionally in folk medicine are emerging as alternative sources for chemotherapeutic compounds. In this study, in vitro leishmanicidal effects of a thymol- and a carvacrol-rich essential oil from leaves of Lippia sidoides Cham. were investigated. The essential oils were extracted and their constituents were characterized by gas chromatography coupled to mass spectrometry (GC/MS). Both essential oils showed significant activity against promastigote forms of Leishmania chagasi. However, we found that carvacrol-rich essential oil was more effective, with IC50/72 h of 54.8 μg/mL compared to 74.1 μg/mL for thymol-rich oil. Carvacrol also showed lower IC50 than thymol. Our data suggest that L. sidoides essential oils are indeed promising sources of leishmanicidal compounds.

Perfil fitoquímico e ensaio microbiológico dos extratos da entrecasca de Maytenus rigida Mart. (Celastraceae) / Phytochemistry and microbiological assay of the bark extracts of Maytenus rigida Mart. (Celastraceae)

Maytenus rigida Mart (Celastraceae), conhecida por "Bom-homem", "Bom-nome", "Cabelo-de-negro", "Casca-grossa" e "Pau-de-colher", é uma arvore de pequeno porte. A entrecasca do caule é empregada popularmente no Nordeste do Brasil no tratamento das dores em geral, infecções e inflamações. O presente trabalho avaliou tanto o perfil fitoquímico de M. rigida por meio de um roteiro analítico, quanto à atividade antibiótica dos extratos pelo método de Kirby-Bauer modificado. Os resultados demonstraram que os extratos etanólico, aquoso, clorofórmico, acetato de etila e hidroalcoólico de M. rigida apresentam atividade antibacteriana contra Escherichia coli, Pseudomonas aeruginosa e Staphylococcus aureus, enquanto que a fração hexânica não exibe qualquer atividade. Catequinas, quinonas, esteróides, triterpenos, saponinas, flavonóides e compostos fenólicos foram detectados na análise fitoquímica.

Maynetus rigida Mart (Celastraceae), known as "Bom-homem", "Bom-nome", "Cabelo-de-negro", "Casca-grossa" and "Pau-de-colher", is a small tree. The stem bark is used by the population in the northeast of Brazil to treat aches, infections and inflammations in general. The present work evaluated both the phytochemistry of M. rigida Mart by an analytical routine, and the antimicrobial activity of the bark extracts by the Kirby-Bauer modified method. Our results showed the aqueous, methanol, chloroform, ethyl acetate and hydroalcoolic extracts of M. rigida Mart has antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, while the hexane extract does not have any activity. Catechins, quinones, steroids, triterpenes, saponins, flavonoids and phenolic compounds were detected by the phytochemical analysis.