ABSTRACT
Abstract This study aimed to chemically characterize the essential oils (EOs) of Cinnamomum zeylanicum (cinnamon) and Eremanthus erythropappus (candeia) and evaluate their acaricidal activity, together with that of their major compounds and cinnamyl acetate derivative, against Rhipicephalus microplus. Essential oil compounds were identified through gas chromatography. The larval packet test (LPT) at concentrations ranging from 0.31 to 10.0 mg/mL and the adult immersion test (AIT) at concentrations between 2.5 and 60.0 mg/mL were performed. (E)-cinnamaldehyde and α-bisabolol were the major compounds in cinnamon (86.93%) and candeia (78.41%) EOs, respectively. In the LPT, the EOs of cinnamon and candeia and the compounds (E)-cinnamaldehyde, α-bisabolol and cinnamyl acetate resulted in 100% mortality at concentrations of 2.5, 2.5, 5.0, 10.0 and 10.0 mg/mL respectively. In the AIT, percentage control values > 95% were observed for cinnamon and candeia EOs, (E)-cinnamaldehyde and α-bisabolol at the concentrations of 5.0, 60.0, 20.0, and 20.0 mg/mL, respectively, whereas cinnamyl acetate showed low activity. We conclude that EOs and their compounds showed high acaricidal activity, whereas the acetylated derivative of (E)-cinnamaldehyde presented less acaricidal activity on R. microplus engorged females.
Resumo Este estudo teve como objetivo caracterizar quimicamente os óleos essenciais (OE) de Cinnamomum zeylanicum (canela) e Eremanthus erythropappus (candeia) e avaliar sua atividade acaricida, juntamente com a de seus principais compostos e do derivado de acetato de cinamila, sobre Rhipicephalus microplus. Os compostos do óleo essencial foram identificados por cromatografia gasosa. Foram realizados o Teste de Pacote de Larvas (TPL), em concentrações variando de 0,31 a 10,0 mg/mL, e o Teste de Imersão de Adultos (TIA), em concentrações entre 2,5 e 60,0 mg/mL. (E)-cinnamaldeído e α-bisabolol foram os principais compostos nos OE da canela (86,93%) e da candeia (78,41%), respectivamente. No TPL, os OEs de canela e candeia, e os compostos (E)-cinnamaldeído, α-bisabolol e acetato de cinamila resultaram em 100% de mortalidade nas concentrações de 2,5, 2,5, 5,0, 10,0 e 10,0 mg/mL, respectivamente. No TIA, valores percentuais de controle >95% foram observados para OE de canela e candeia, (E)-cinnamaldeído e α-bisabolol nas concentrações de 5,0, 60,0, 20,0 e 20,0 mg/mL, respectivamente, enquanto o acetato de cinamila apresentou baixa atividade. Conclui-se que os OEs e seus compostos apresentaram alta atividade acaricida, enquanto o derivado acetilado do (E)-cinnamaldeído apresentou menor atividade acaricida em fêmeas ingurgitadas de R. microplus.
Subject(s)
Animals , Oils, Volatile/pharmacology , Rhipicephalus , Acaricides/pharmacology , Cinnamates , Cinnamomum zeylanicum , LarvaABSTRACT
Plants are invaluable sources of pharmaceutical products and Brazil, in particular, has yielded an incredible array of plant and animal products that have drawn the attention of ethnopharmacologists from around the world. Ouratea is a genus of tropical plants within the Ochnaceae. Ouratea is widespread throughtout the tropics, with species in Costa Rica, Brazil, Jamaica, and Kenya. The search for compounds with antimicrobial activity is urgent and indispensable for the treatment of infectious diseases caused by microorganisms resistant to traditional antimicrobial drugs. A screening was conducted with organic extracts from two species, from roots and leaves of Ouratea hexasperma var. planchonii Engl. and leaves and branches of Ouratea parviflora Engl., to identify plant extracts with antifungal properties against Candida albicans. Initially, minimal inhibitory concentrations (MICs) were determined in C. albicans cellular suspension in Sabouraud medium, in a range of 0.060-3.0 mg/ml. Fractions OHRMWE (Ethyl acetate fraction) and OHLMWB (Buthanol fraction) obtained by solvents partition of methanol:water extract from Ouratea hexasperma with ethyl acetate from the roots and n-butanol from the leaves, respectively, showed a higher antifungal activity. The antifungal activity of these extracts was also compared in growth delay of C. albicans cultures.