Circadian Rhythm and larvicidal activity against Aedes aegypti of essential oils from Croton piauhiensis

Resumo

Croton piauhiensis, popularly known as velame, is a restricted species of Caatinga biome. In this context, this work aims to study the circadian cycle and larvicidal activity against Aedes aegypti of the essential oils of C. piauhiensis. The chemical composition of the essential oils from leaves obtained by hydrodistillation were analyzed and identified by GC-MS and GC-FID. According to the results, the circadian study showed differences in the chemical composition of oils extracted at different hours of the day from C. piauhiensis leaves. The major components of essential oils from C. piauhiensis at 8 a.m., 12 a.m and 17 p.m. were β-caryophyllene 21.58, 34.69 and 21.01%, D-limonene 13.47, 13.75 and 16.35, γ-terpinene 10.08, 8.00 and 9.60%, Germacrene D 9.56, 10.42 and 8.71%, respectively. Sesquiterpenes contents were 52.59% and 67.29% at 8h and 12h, respectively. On the other hand, at 17h there was a greater predominance of the monoterpenes (50.77%). Regarding the larvicidal activity, the essential oils of C. piauhiensis showed larvicidal activity with LC50 = 336.8 μg / mL (oil extracted at 8:00 h), LC50 = 283.9 μg/mL (oil extracted from 12:00 h) and LC50 = 252.5 μg / ml (oil extracted at 17:00 h).