The composition of plant oils and extracts is known to vary according to local climatic and environmental conditions. Furthermore, some oils with the same common name may be derived from different plant species. Secondly, the method used to assess antimicrobial activity, and the choice of test organism(s) varies between publications. A method frequently used to screen plant extracts for antimicrobial activity is the agar disc diffusion technique[7]. An antioxidant is a molecule capable of slowing or preventing the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons from a substance to an oxidizing agent. Oxidation reactions can produce free radicals, which start chain reactions that damage cells. Antioxidants terminate these chain reactions by removing free radical intermediates, and inhibit other oxidation reactions by being oxidized themselves. As a result, antioxidants are often reducing
agents such as thiols, ascorbic acid or polyphenols[8].