title: Critical analysis of current methods for assessing the in vitro antioxidant and antibacterial activity of plant extracts.
abstract: 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the methods used by many are not necessarily optimal; a result of poor standardization, redundant assays and/or outdated methodology.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.
authors.affiliation: School of Science, Monash University Malaysia, Bandar Sunway, 46150 Petaling Jaya, Selangor, Malaysia. Electronic address: tan.ban.lee@monash.edu.
authors.forename: Joash Ban Lee
authors.initials: JB
authors.lastname: Tan
authors.affiliation: School of Science, Monash University Malaysia, Bandar Sunway, 46150 Petaling Jaya, Selangor, Malaysia.
authors.forename: Yau Yan
authors.initials: YY
authors.lastname: Lim
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D010636:Phenols / Q000032:analysis; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D016166:Free Radical Scavengers; D010636:Phenols; D010936:Plant Extracts
keywords: 1,1′-Diphenyl-2-picrylhydrazyl (DPPH) (PubChem CID: 2735032); 2,2′-Azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) (PubChem CID: 5815211); 2,2′-Azobis-2-methyl-propanimidamide dihydrochloride (AAPH) (PubChem CID: 76344); AlCl(3) (PubChem CID: 24012); Bacterial susceptibility testing; DMSO (PubChem CID: 679); Ferric tripyridyltriazine (PubChem CID: 77258); Fluorescein (PubChem CID: 16850); Folin–Ciocalteu reagent; Free radical scavenging; Total phenolic content; Tween 80 (PubChem CID: 5281955); p-Dimethylaminocinnamaldehyde (DMACA) (PubChem CID: 5284506)