Antichemotactic and Antifungal Action of the Essential Oils from Cryptocarya aschersoniana, Schinus terebinthifolia, and Cinnamomum amoenum.

The purpose of this work was to determine the chemical composition and evaluate the antichemotactic, antioxidant, and antifungal activities of the essential oil obtained from the species Cryptocarya aschersoniana Mez, Cinnamomum amoenum (Ness & Mart.) Kosterm., and Schinus terebinthifolia Raddi, as well as the combination of C. aschersoniana essential oil and terbinafine against isolates of dermatophytes. Allo-aromadendrene, bicyclogermacrene, and germacrene B were identified as major compounds in essential oils. The essential oil of C. aschersoniana shown 100 % inhibitory effect on leukocyte migration at the concentration of 10 µg/mL while S. terebinthifolia oil presented 80.1 % inhibitory effect at the same concentration. Only S. terebinthifolia oil possessed free-radical-scavenging activity which indicates its antioxidant capacity. The essential oils were also tested against fungal isolates of dermatophyte species (Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis and Microsporum gypseum), resulting in MIC ranging from 125 µg/mL to over 500 µg/mL. C. aschersoniana oil combined with terbinafine resulted in an additive interaction effect. In this case, the essential oil may act as a complement to conventional therapy for the topical treatment of superficial fungal infections, mainly because it is associated with an anti-inflammatory effect.

Influence of Monoterpenes in Biological Activities of Nectandra megapotamica (Spreng.) Mez Essential Oils.

Investigating the influence of seasonal variations on biological activities is important for pharmacological studies and metabolic engineering. Therefore, this study was conducted to determine the variation of the chemical composition of essential oils obtained from Nectandra megapotamica leaves, collected at different stages of plant development, as well as its influence on the biological activities. A total of 38 compounds were identified that accounted for 97⁻99.2% of the chemical composition of the oils. Major differences were observed in the monoterpenic fraction, representing 5.1% of the compounds identified in the productive rest phase to 37.1% in the blooming phase. Bicyclogermacrene and germacrene D were the predominant compounds identified in the oil of all collections. Furthermore, limonene, ß-pinene, and spathulenol were identified predominantly in the samples of blooming and fruiting phases. The oils exhibited significant antichemotactic activity and different effects in scavenging the radical 2,2-diphenyl-1-picrylhydrazyl. Variations were also observed in the antifungal activity, with the minimum inhibitory concentrations ranging from 125 to 500 µg/mL. These results demonstrate the influence of monoterpenes, primarily limonene, α-pinene, and ß-pinene, on the bioactivities of the oil. Studies investigating the variations in the chemical composition of essential oil may offer a strategy to produce a compound or a group of compounds of interest to industries with a specific pharmacological focus.

Antifungal mechanism of action of Schinus lentiscifolius Marchand essential oil and its synergistic effect in vitro with terbinafine and ciclopirox against dermatophytes.

OBJECTIVES: The aim of this study was to evaluate the antifungal, antichemotactic and antioxidant activities of Schinus lentiscifolius essential oil, as well as its combined effect with terbinafine and ciclopirox, against dermatophytes. METHODS: Essential oil was analysed by GC-MS. The antifungal activity and the mechanism of action were determined by broth microdilution, sorbitol and ergosterol assays, as well as scanning electron microscopy. The checkerboard method was used for evaluating the interactions with commercial antifungal agents. The antioxidant and antichemotactic activities were measured using the DPPH and the modified Boyden chamber methods, respectively. KEY FINDINGS: Chemical analysis revealed the presence of 33 compounds, the primary ones being γ-eudesmol (12.8%) and elemol (10.5%). The oil exhibited 97.4% of antichemotactic activity and 37.9% of antioxidant activity. Antifungal screening showed effect against dermatophytes with minimum inhibitory concentration values of 125 and 250 µg/ml. Regarding the mechanisms of action, the assays showed that the oil can act on the fungal cell wall and membrane. Synergistic interactions were observed using the combination with antifungals, primarily terbinafine. CONCLUSIONS: Schinus lentiscifolius essential oil acted as a chemosensitizer of the fungal cell to the drug, resulting in an improvement in the antifungal effect. Therefore, this combination can be considered as an alternative for the topical treatment of dermatophytosis.