Histochemical, phytochemical and biological screening of Plinia cauliflora (DC.) Kausel, Myrtaceae, leaves

Abstract

RESUMO: "Rastreamento histoquímico, fitoquímico e biológico de folhas de Plinia cauliflora (DC.) Kausel (Myrtaceae)". No presente trabalho, foram investigadas a composição química e atividades biológicas de extratos brutos obtidos com etanol 50%, etanol 70%, acetona:água (7:3; v/v) e clorofórmio das folhas de Plinia cauliflora (DC.) Kausel, Myrtaceae, uma árvore nativa de várias regiões do Brasil. Os rastreamentos histoquímico e fitoquímico foram feitos de acordo com reações de caracterização e cromatografia em camada delgada. Para auxiliar na padronização dos extratos foram realizadas determinações do teor de fenóis totais e de flavonoides totais, espectrofotometricamente. A atividade antioxidante foi analisada pela porcentagem de sequestro de radicais livres usando solução de DPPH. A atividade antimicrobiana foi avaliada frente a bactérias patogênicas Gram-positivas, Gram-negativas e espécies de Candida utilizando os métodos de difusão em ágar e determinação da concentração inibitória mínima (MIC) de acordo com métodos padronizados. As folhas apresentaram lipídeos nas cavidades secretoras e fenóis, principalmente taninos, nas nervuras e parênquima paliçádico. Os extratos polares apresentaram flavonoides, taninos, alto teor de fenóis totais e de flavonoides totais. Os extratos mostraram elevada atividade antioxidante e a atividade antimicrobiana foi melhor contra as espécies de Candida do que contra as bactérias.Unitermos: Plinia cauliflora, Myrtaceae, rastreamento químico, atividade antioxidante, atividade antimicrobiana. ABSTRACT:In this work, chemical and biological activities of crude extracts obtained with 50% ethanol, 70% ethanol, acetone:water (7:3; v/v) and chloroform of Plinia cauliflora (DC.) Kausel, Myrtaceae, leaves, a native tree from several regions of Brazil, was investigated. Histochemical and phytochemical screenings were done according to characterization reactions and thin layer chromatography. To assist in extracts standardization, total phenol and flavonoids content spectrophotometric was performed. Antioxidant activity was analyzed by percentage of radical scavenging using DPPH solution. Antimicrobial activity was evaluated against Gram-positive, Gram-negative pathogenic bacteria and species of Candida using agar diffusion and minimal inhibitory concentration (MIC) determination methods according to standard methods. The leaves presented lipids at secretory cavity and phenols, mainly tannins, in nervures and palisade parenchyma. Polar extracts showed flavonoids, tannins and high content of phenols and flavonoids. The extracts showed great antioxidant activity and antimicrobial activity was better against Candida species than against bacteria.

Interspecific variation in the allelopathic potential of the family Myrtaceae

“…Keszei et al (2008) stated that the leaves of Myrtaceae species have high concentrations of terpenes and that these compounds show substantial qualitative and quantitative variations between each taxon, population and individual. Other phytochemical studies of Myrtaceae leaves have identifi ed sesquiterpenes, triterpenes, fl avonoids and alkaloids in Calycorectes psidiifl orus (Domingues et al 2010); fl avonoids, tannins and phenols in Plinia caulifl ora (Souza-Moreira et al 2010); and fl avonoids in Baeckea frutescens (Kamiya & Satake 2010).…”

Anti-Candida Targets and Cytotoxicity of Casuarinin Isolated from Plinia cauliflora Leaves in a Bioactivity-Guided Study

“…A preliminary phytochemical study of the ethanolic extract of the leaves confirmed the presence of hydrolysable tannins and flavonoids. Biological assays detected antioxidant (94.8% of radical scavenging capacity of 2,2-diphenyl-1-picryl-hydrazyl—DPPH) and antimicrobial activities, especially antifungal activity of the 70% ethanolic extract of the leaves against Candida albicans , Candida parapsilosis and Candida tropicalis (MIC of 625 µg/mL) [5]. It is well-known that Candida species under predisposing conditions can cause a range of infections from oral thrush and vaginitis, affecting the superficial mucosa, to candidaemia and systemic candidiasis in patients with compromised immunity [6].…”

Chemical and Biological Evaluation of Essential Oils from Two Species of Myrtaceae — Eugenia uniflora L. and Plinia trunciflora (O. Berg) Kausel

“…In folk medicine, species of Plinia have been used in the treatment of stomach disorders, throat afflictions, and diabetes [ 19 ]. Biological properties of essential oil from P. trunciflora have not been reported, but leaf extract showed antioxidant and antimicrobial activities [ 20 ]. In a continuation of our systematic studies on pharmacologically active volatiles from Brazilian plants [ 21 , 22 ] we describe in this paper an evaluation of the chemical composition and antimicrobial activity of essential oils from leaves of E. uniflora and, for the first time, antimicrobial activity of essential oil from the leaves of P. trunciflora .…”