Critical analysis of current methods for assessing the in vitro antioxidant and antibacterial activity of plant extracts

• Published in: Food chemistry 2015-04, Vol.172, p.814-822
• Main Authors: Tan, Joash Ban Lee, Lim, Yau Yan
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Antioxidants - pharmacology; Bacterial susceptibility testing; Free Radical Scavengers - pharmacology; Free radical scavenging; Humans; In Vitro Techniques; Phenols - analysis; Plant Extracts - analysis; Plant Extracts - pharmacology; Total phenolic content
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2014.09.141

•Discusses selection of optimal antioxidant/antibacterial assays.•Discusses strengths and weaknesses of many common antioxidant/antibacterial assays.•Highlights alternative assays. Natural product research is an active branch of science, driven by the increased value placed on individual health and well-being. Many naturally-occurring phytochemicals in plants, fruits and vegetables have been reported to exhibit antioxidant and antibacterial activity; often touted as being beneficial for human health. In vitro screening is a common practice in many research laboratories as a means of rapidly assessing these properties. However, the methods used by many are not necessarily optimal; a result of poor standardization, redundant assays and/or outdated methodology. This review primarily aims to give a better understanding in the selection of in vitro assays, with emphasis placed on some common assays such as the total phenolic content assay, free radical scavenging activity, disc-diffusion and broth microdilution. This includes a discussion on the reasons for choosing a particular assay, its strengths and weaknesses, ways to improve the accuracy of results and alternative assays.