Antioxidant activities of Carum carvi L. and Coriandrum sativum L., Apiaceae essential oils

Many aromatic plants are today considered as the important sources for the extraction of compounds with strong antioxidant activity. Caraway (Carum carvi L.) and coriander (Coriandrum sativum L.) are two spices widely used as spices, in folk medicine, pharmacy and flavoring agents. In this study, antioxidant activity of essential oils of these two plants in four different model systems is presented. Antioxidant activity was evaluated as a free radical scavenging capacity (RSC), together with the effect on lipid peroxidation (LP). The chemical composition of essential oils was evaluated by GC-MS and TLC. The antioxidant effects were evaluated by neutralization of stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and hydrogen peroxide. Effects on LP were evaluated following the activities of examined essential oils in in Fe²⁺/ascorbate and Fe²⁺/H₂O₂ systems of induction [1]. Investigated essential oils reduced the DPPH radical formation (IC₅₀=4.1µl/ml for caraway and 53.5µl/ml for coriander) and H₂O₂ (IC₅₀=5.77µl/ml for caraway and 5.33µl/ml for coriander) in dose dependent manner. Strong inhibition of LP in both systems of induction was observed for the caraway essential oil. On contrary, coriander essential oil exhibited prooxidant activity in Fe²⁺/H₂O₂ system of induction from -161.53 to –257.79% of inhibition in the applied concentrations ranging from 2.5 to 12.5µl/ml). Differences obtained in the antioxidant activity could be explained by the chemical composition of the essential oils. In the essential oil of caraway carvone (78.8%) was the main constituent. Linalool (74.6%) was the dominant compound in the coriander essential oil and for this substance is confirmed that in some test systems could exhibit strong prooxidant activity [2].

References: 1. Bozin et al. (2006)J. Agric. Food Chem. 54: 1822–1828. 2. Rubert G., Baratta M.T. (2000) Food Chem. 69: 167–174.