Chemical Variation and Pharmacological Properties of Dyssodia decipiens Essential Oil

Dyssodia decipiens is one of the seven recognized species within the Dyssodia genus, which has economic and social relevance in Mexico. Herein, we report on the volatile characterization and pharmacological activity of D. decipiens. The essential oils (2017-2019) contained verbenone (30.8-60.9 %), limonene (5.6-35.5 %), β-caryophyllene (7.8-19.8 %) and linalool (4.5-12.4 %) as major constituents along the studied years. Antifungal properties were probed on Candida albicans ATCC 90028, ATCC 10231 (fluconazole resistant) and five clinical isolates (IS1-IS5). Flower essential oils had the best anti-C. albicans activity (MIC 59.2-93.5 μg mL^-1 ), and limonene (MIC 125.5-188.4 μg mL^-1 ) and β-caryophyllene (MIC 104.3-184.2 μg mL^-1 ) were involved in this effect. SEM examination revealed that D. decipiens essential oils produced an evident lysis on the fungus. Mosquito repellent activity was demonstrated on Aedes aegypti, a vector of dengue, chikungunya and zika viruses. The repellent activity of leaf essential oils (20 %) was effective within 1-5 h post-treatment (>90 %) and it was stronger (p<0.01) than that of commercial DEET. The evaluation of the four major volatiles (10 % each) produced similar results to those of essential oils. Finally, leaf essential oils showed a moderate antiproliferative activity on the lines OVCAR-3 (LD₅₀ 56.5-85.7 μg mL^-1 ), and verbenone (LD₅₀ 65.3 μg mL^-1 ) and β-caryophyllene (LD₅₀ 43.6 μg mL^-1 ) were linked to this effect.