Seasonal variation in the chemical composition, antimicrobial and mutagenic potential of essential oils from Piper cernuum

Environmental factors such as seasonality can influence the chemical composition, the pharmacological activity and potential toxicity of essential oils. The aim of this study was to evaluate the influence of seasonality on the chemical composition, the antimicrobial potential cytotoxic and mutagenic of essential oils and fractions from the hydrolate of Piper cernuum. The essential oils and hydrolate fractions obtained from the dried leaves, were analyzed by means of Gas Chromatography, Gas Chromatography-Mass Spectrometry and Carbon-13 Nuclear Magnetic Resonance. Twenty-seven constituents were identified, representing 92.9 to 98.4% of the oils in different seasons of the year. trans-Dihydroagarofuran, 4-epi-cis-dihidroagarofuran, γ-eudesmol, β-caryophyllene, elemol, α-pinene and camphene were found as the major compounds. Furthermore, was found that the essential oil did not exhibit mutagenic potential. The oils exhibited a very interesting antimicrobial profile against Staphylococcus aureus, Bacillus subtilis and Streptococcus pyogenes and dermatofites including Microsporum gypseum, Trichophyton mentagrophytes, Trichophyton rubrum, Epidermophyton flocosum and opportunistic yeast Criptococcus neoformans. The dichloromethane and ethyl acetate fractions were more active against dermatophyte fungi. The seasonality influenced the antimicrobial activity and quantitative composition of substances in essential oils, but could not establish a direct correlation between the concentrations of compounds with improved antimicrobial activity.