Οlive tree blossom polyphenolic extracts exert antioxidant and antimutagenic activities in vitro and in various cell lines

Abstract

Olive oil has held a prominent place in the Mediterranean diet since ancient times due to its beneficial effects on human health thus, becoming the subject of great scientific interest. Although numerous studies have examined the biological action of olive and olive oil extracts, the literature lacks studies investigating the putative antioxidant capacity of olive tree flower extracts. Given that olive tree flowers are actually by-products of the olive oil production process with high waste burden for the environment, it becomes evident that their exploitation could increase their added value. Therefore, in this study the potential antioxidant action of four olive flower extracts was investigated. All the extracts exerted potent antioxidant activity as indicated using the DPPH • and ABTS •+ assays, as well as antigenotoxic and antimutagenic properties, identified by the results of the plasmid relaxation assay and the Ames test, respectively. Furthermore, the extracts also improved redox status of four cell lines (i.e., EA.hy926, C2C12, HeLa, and HepG2) enhancing reduced glutathione and reducing reactive oxygen species levels using flow cytometry. Taking into account that during olive tree cultivation a considerable amount of olive flowers is generated, the waste burden is high and the management is difficult. Given the optimistic findings of the present study, we believe that the flower-derived extracts may have high added value since they could be used as antioxidants or as foodstuff, food additives and functional food constituents.

Assessment of Antioxidant and Antimutagenic Properties of Red and White Wine Extracts In Vitro

“…The free-radical scavenging activity (RSC) of wine extracts was evaluated by a 2,2-Diphenyl-1-picrylhydrazyl (DPPH • ) radical assay [ 83 ], as previously described, with slight modifications [ 49 , 84 , 85 , 86 ]. Briefly, 900 μL of methanol and 50 μL of freshly prepared methanolic solution of DPPH • radical (2 mM) were mixed with 50 μL of each wine extract in different concentrations (ranging from 1.56 to 150 μg/mL).…”

“…The assay of DNA relaxation from peroxyl radicals has already been described [ 49 , 85 , 94 , 95 , 96 ]. The plasmid (pBluescript SK+, Fermentas, Waltham, MA, USA) DNA normally exists in the supercoiled conformation but, following a single-strand break, it is converted to an open circular conformation.…”

“…The antimutagenic capacity of the tested wine extracts was evaluated through the application of an Ames test using Salmonella typhimurium bacterium strain TA102 (MolTox), as reported by Maron and Ames and previously described [ 85 , 97 ]. Briefly, 700 μL of the bacterium culture was used to inoculate 30 mL of autoclaved Oxoid nutrient broth no.…”

Biofunctional Feed Supplemented With By-products of Olive Oil Production Improves Tissue Antioxidant Profile of Lambs

“…The chemical composition of OMW has already been published from our research group (9). Indicatively, it was found to be rich in four polyphenols, namely hydroxytyrosol, tyrosol, caffeic acid, and pcoumaric acid, which are main constituents of olive oil (41,42).…”

Methodology for the biofunctional assessment of honey (Review)

“…The FC assay is not specific for particular groups of phenolic compounds but is used for the determination of their total concentration in various extracts (40,41). Typically, the TPC is determined via a gallic acid (GA) standard curve (42,43). Gao et al (44) suggested that the main polyphenolic component of each food extract may be used as the assay standard.…”