Seasonal effect in essential oil composition and antioxidant activity of Plectranthus amboinicus leaves

In view of the increasing search for natural products with biological activities, such as essential oils are of high quality because of their therapeutic and economic importance and represent the second class of natural compounds with the largest number of active constituents and production through Plants minimizes the environment and sanitary impacts . The objective of the present work is to assess the seasonal effect on the composition and antioxidant activity of essential oil in leaves of Plectranthus amboinicus (Lour.) Spreng using hydro and steam distillation techniques. With regarding to the extraction methodology of essential oils from the P. amboinicus, the hydrodistillation technique is the most efficient in obtaining the volatile product with the best features for the determination of antioxidant activity. The analyses of the essential oil indicated a similarity in their composition, being observed the Carvacrol as major compound in almost all analysis, except in January 2015 using steam distillation extraction. Regarding antioxidant activity and seasonality, it was verified that in October 2014 obtained the best value of inhibitory concentration, with IC50 = 124.97 ppm. However, it was possible to obtain the essential oil from the P. amboinicus leaves through hydro and steam distillation methodologies, but also noted the seasonality influence on it's the context of antioxidant capacity.