{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,17]],"date-time":"2026-10-17T21:00:15Z","timestamp":1792270815293,"version":"4.4.0"},"reference-count":53,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2022,6,29]],"date-time":"2022-06-29T00:00:00Z","timestamp":1656460800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001321","name":"National Research Foundation","doi-asserted-by":"publisher","award":["99219"],"award-info":[{"award-number":["99219"]}],"id":[{"id":"10.13039\/501100001321","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001321","name":"National Research Foundation","doi-asserted-by":"publisher","award":["86923"],"award-info":[{"award-number":["86923"]}],"id":[{"id":"10.13039\/501100001321","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001321","name":"National Research Foundation","doi-asserted-by":"publisher","award":["23015"],"award-info":[{"award-number":["23015"]}],"id":[{"id":"10.13039\/501100001321","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001321","name":"National Research Foundation","doi-asserted-by":"publisher","award":["001.401"],"award-info":[{"award-number":["001.401"]}],"id":[{"id":"10.13039\/501100001321","id-type":"DOI","asserted-by":"publisher"}]},{"name":"South African Medical Research Council","award":["99219"],"award-info":[{"award-number":["99219"]}]},{"name":"South African Medical Research Council","award":["86923"],"award-info":[{"award-number":["86923"]}]},{"name":"South African Medical Research Council","award":["23015"],"award-info":[{"award-number":["23015"]}]},{"name":"South African Medical Research Council","award":["001.401"],"award-info":[{"award-number":["001.401"]}]},{"name":"Research Committee Individual Research Grant, WITS University","award":["99219"],"award-info":[{"award-number":["99219"]}]},{"name":"Research Committee Individual Research Grant, WITS University","award":["86923"],"award-info":[{"award-number":["86923"]}]},{"name":"Research Committee Individual Research Grant, WITS University","award":["23015"],"award-info":[{"award-number":["23015"]}]},{"name":"Research Committee Individual Research Grant, WITS University","award":["001.401"],"award-info":[{"award-number":["001.401"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Culinary herbs and spices are known to be good sources of natural antioxidants. Although the antioxidant effects of individual culinary herbs and spices are widely reported, little is known about their effects when used in combination. The current study was therefore undertaken to compare the antioxidant effects of crude extracts and essential oils of some common culinary herbs and spices in various combinations. The antioxidant interactions of 1:1 combinations of the most active individual extracts and essential oils were investigated as well as the optimization of various ratios using the design of experiments (DoE) approach. The 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays were used to determine the antioxidant activity, and MODDE 9.1\u00ae software (Umetrics AB, Umea, Sweden) was used to determine the DoE. The results revealed synergism for the following combinations: Mentha piperita with Thymus vulgaris methanol extract (\u03a3FIC = 0.32 and \u03a3FIC = 0.15 using the DPPH and FRAP assays, respectively); Rosmarinus officinalis with Syzygium aromaticum methanol extract (\u03a3FIC = 0.47 using the FRAP assay); T. vulgaris with Zingiber officinalis methanol extracts (\u03a3FIC = 0.19 using the ABTS assay); and R. officinalis with Z. officinalis dichloromethane extract (\u03a3FIC = 0.22 using the ABTS assay). The DoE produced a statistically significant (R2 = 0.905 and Q2 = 0.710) model that was able to predict extract combinations with high antioxidant activities, as validated experimentally. The antioxidant activities of the crude extracts from a selection of culinary herbs and spices were improved when in combination, hence creating an innovative opportunity for the future development of supplements for optimum health.<\/jats:p>","DOI":"10.3390\/molecules27134196","type":"journal-article","created":{"date-parts":[[2022,6,29]],"date-time":"2022-06-29T22:43:28Z","timestamp":1656542608000},"page":"4196","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Optimization of Antioxidant Synergy in a Polyherbal Combination by Experimental Design"],"prefix":"10.3390","volume":"27","author":[{"given":"Tsholofelo M.","family":"Mapeka","sequence":"first","affiliation":[{"name":"Department of Pharmaceutical Sciences, Tshwane University of Technology, Pretoria 0001, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maxleene","family":"Sandasi","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, Tshwane University of Technology, Pretoria 0001, South Africa"},{"name":"SAMRC Herbal Drugs Research Unit, Faculty of Science, Tshwane University of Technology, Pretoria 0001, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6810-2981","authenticated-orcid":false,"given":"Alvaro M.","family":"Viljoen","sequence":"additional","affiliation":[{"name":"Department of Pharmaceutical Sciences, Tshwane University of Technology, Pretoria 0001, South Africa"},{"name":"SAMRC Herbal Drugs Research Unit, Faculty of Science, Tshwane University of Technology, Pretoria 0001, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4859-1845","authenticated-orcid":false,"given":"Sandy F.","family":"van Vuuren","sequence":"additional","affiliation":[{"name":"Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of Witwatersrand, Parktown, Johannesburg 2193, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,6,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1080\/10408398.2011.585525","article-title":"Antioxidant potential of spices and their active constituents","volume":"54","author":"Srinivasan","year":"2014","journal-title":"Crit. 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