Antioxidant Activities of Essential Oil of Psidium Guajava L. Leaves

The antioxidant potential of guava leaves essential oil (EO) was evaluated by using free radical (DPPH) scavenging assay, reducing power assay and also beta-carotene bleaching assay. Here, butylated hydroxytoulene (BHT) and ascorbic acid were used as standard antioxidants. Guava leaves EO showed a concentration-dependent free radical scavenging activity by inhibiting the DPPH radicals but served as a moderate antioxidant with IC50 value of 460.37 ± 1.33 μg/mL. Guava leaves EO possess moderate inhibition of oxidation of beta-carotene with percentage of inhibition (I %) value of 81.67 ± 1.48% in beta-carotene bleaching assay. The total phenolic content of guava leave EO was also evaluated spectrophotometrically according to Folin-Ciocalteu's phenol method and expressed in gallic acid equivalents (GAE). Remarkably high total phenolic content 495.93 ± 7.88 mg of GAE/g of EO was obtained. This study revealed that guava leaves EO comprise moderate potential source of natural antioxidants.