Atividade antifúngica de extratos de capim santo obtidos por diferentes solventes frente a Colletotrichum musae.

Abstract

Holy grass (Cymbopogon citratus) is an herb widely used in folk medicine in the form of teas, infusions and/or decoctions. It is a plant that has in its composition secondary metabolites responsible for antioxidant, anti-inflammatory, antimicrobial actions, among others. Given these potentials, this study aims to obtain extracts of capim santo by different solvents, determining its bioactive compounds and the in vitro effect against the mycelial growth of Colletotrichum musae. For this, the plant material was properly sanitized, dried and submitted to the extraction process involving three different solvents (alcoholic, hydroalcoholic and aqueous). Then, the fresh and dry samples and the elaborated extracts were analyzed for the contents of chlorophylls, carotenoids, flavonoids, anthocyanins and total phenolic compounds. For antifungal analysis, the species C. musae was treated with the different extracts at concentrations of 0.0%; 0.5% and 1.0% in relation to PDA culture medium (Potato Dextrose Agar). It was possible to observe high levels of bioactives, especially the total phenolics (responsible for antimicrobial actions), which obtained a concentration of 1538.92 ± 30.88 mg/100g for the alcoholic extract. In fact, the alcoholic extract showed the best inhibition against the studied phytopathogen (about 70%). Already the aqueous and hydroalcoholic extracts that registered 1240.5 ± 20.26 and 976.34 ± 11.41 mg/100g for phenolics, and achieved an inhibition of approximately 40% and 25%, respectively. Therefore, it was possible to observe that ethanol as a solvent showed greater efficiency in extracting bioactive compounds. In addition, the alcoholic extract achieved the best use in reducing the mycelial growth of C. musae, proving to be an alternative in the control of the pathogenic species.