Model development for predicting in vitro bio-capacity of green rooibos extract based on composition for application as screening tool in quality control
dc.contributor.author | Viraragavan, Amsha | en_ZA |
dc.contributor.author | Hlengwa, Nokulunga | en_ZA |
dc.contributor.author | De Beer, Dalene | en_ZA |
dc.contributor.author | Riedel, Sylvia | en_ZA |
dc.contributor.author | Miller, Neil | en_ZA |
dc.contributor.author | Bowles, Sandra | en_ZA |
dc.contributor.author | Walczak, Beata | en_ZA |
dc.contributor.author | Muller, Christo | en_ZA |
dc.contributor.author | Joubert, Elizabeth | en_ZA |
dc.date.accessioned | 2022-07-11T08:57:59Z | |
dc.date.available | 2022-07-11T08:57:59Z | |
dc.date.issued | 2020-03-09 | |
dc.description | CITATION: Viraragavan, A. et al. 2020. Model development for predicting in vitro bio-capacity of green rooibos extract based on composition for application as screening tool in quality control. Food & Function, 11:3084-3094. doi:10.1039/C9FO02480H | en_ZA |
dc.description | The original publication is available at http://pubs.rsc.org/en/Journals/Journal/FO | en_ZA |
dc.description.abstract | Mounting evidence of the ability of aspalathin to target underlying metabolic dysfunction relevant to the development or progression of obesity and type 2 diabetes created a market for green rooibos extract as a functional food ingredient. Aspalathin is the obvious choice as a chemical marker for extract standardisation and quality control, however, often the concentration of a single constituent of a complex mixture such as a plant extract is not directly related to its bio-capacity, i.e. the level of in vitro bioactivity effected in a cell system at a fixed concentration. Three solvents (hot water and two EtOH–water mixtures), previously shown to produce bioactive green rooibos extracts, were selected for extraction of different batches of rooibos plant material (n = 10). Bio-capacity of the extracts, tested at 10 μg ml−1, was evaluated in terms of glucose uptake by C2C12 and C3A cells and lipid accumulation in 3T3-L1 cells. The different solvents and inter-batch plant variation delivered extracts ranging in aspalathin content from 54.1 to 213.8 g kg−1. The extracts were further characterised in terms of other major flavonoids (n = 10) and an enolic phenylpyruvic acid glucoside, using HPLC-DAD. The 80% EtOH–water extracts, with the highest mean aspalathin content (170.9 g kg−1), had the highest mean bio-capacity in the respective assays. Despite this, no significant (P ≥ 0.05) correlation existed between aspalathin content and bio-capacity, while the orientin, isoorientin and vitexin content correlated moderately (r ≥ 0.487; P < 0.05) with increased glucose uptake by C2C12 cells. Various multivariate analysis methods were then applied with Evolution Program-Partial Least Squares (EP-PLS) resulting in models with the best predictive power. These EP-PLS models, based on all quantified compounds, predicted the bio-capacity of the extracts for the respective cell types with RMSECV values ≤ 11.5, confirming that a complement of compounds, and not aspalathin content alone, is needed to predict the in vitro bio-capacity of green rooibos extracts. Additionally, the composition of hot water infusions of different production batches of green rooibos (n = 29) at ‘cup-of-tea’ equivalence was determined to relate dietary supplementation with the extract to intake in the form of herbal tea. | en_ZA |
dc.description.version | Publishers version | en_ZA |
dc.format.extent | 11 pages : illustrations | en_ZA |
dc.identifier.citation | Viraragavan, A. et al. 2020. Model development for predicting in vitro bio-capacity of green rooibos extract based on composition for application as screening tool in quality control. Food & Function, 11:3084-3094. doi:10.1039/C9FO02480H | en_ZA |
dc.identifier.issn | 2042-650X (online) | |
dc.identifier.issn | 2042-6496 (print) | |
dc.identifier.other | doi:10.1039/C9FO02480H | |
dc.identifier.uri | http://hdl.handle.net/10019.1/125484 | |
dc.language.iso | en_ZA | en_ZA |
dc.publisher | Royal Society of Chemistry | en_ZA |
dc.rights.holder | Authors retain copyright | en_ZA |
dc.subject | In vitro bio-capacity | en_ZA |
dc.subject | Green rooibos extract | en_ZA |
dc.subject | Rooibos tea -- Quality | en_ZA |
dc.subject | Treatment of metabolic diseases | en_ZA |
dc.subject | Green rooibos extract characterisation | en_ZA |
dc.title | Model development for predicting in vitro bio-capacity of green rooibos extract based on composition for application as screening tool in quality control | en_ZA |
dc.type | Article | en_ZA |