Metabolic profiling of Greek honey samples and evaluation of their antioxidant activity

MI Stavropoulou; P Polychronopoulos; M Zervos; K Stathopoulou; D Abatis; V Boznou; GP Voulgaridou; A Pappa; S Eftaxia; A Gousia; E Gikas; K Gardikis; N Aligiannis

doi:10.1055/s-0035-1565839

Metabolic profiling of Greek honey samples and evaluation of their antioxidant activity

MI Stavropoulou ¹, P Polychronopoulos ¹, M Zervos ¹, K Stathopoulou ¹, D Abatis ¹, V Boznou ¹, GP Voulgaridou ³, A Pappa ³, S Eftaxia ⁴, A Gousia ⁴, E Gikas ⁵, K Gardikis ², N Aligiannis ¹

¹Department of Parmacognosy and Natural Products Chemistry, Faculty of Pharmacy, University of Athens, 15771, Athens, Greece
²Apivita SA Industrial Park of Markopoulo Mesogaias, 19003 Markopoulo Attiki, Athens, Greece
³Department of Molecular Biology and Genetics, Democritus University of Thrace, 68100, Alexandroupolis, Greece
⁴Faculty of Medicine, University of Ioannina, Ioannina, Greece
⁵Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Athens, 15771, Athens, Greece

Abstract

Physicochemical properties and organoleptic features of honey vary according to its floral origin, geographical and seasonal conditions. However the content of secondary metabolites possessing significant biological properties plays an important role in consumers' demand. In this study, we investigate the metabolic profile of several honey samples from different regions of Greece using GCMS, HPTLC and NMR techniques. Initially the floral sources of honeys were certified with pollen analysis. An extraction protocol based on the use of macroporus resin XAD-4 was developed to obtain fractions enriched in the components of interest such as phenolic compounds. Therefore, resin was stirring with aqueous extracts of honeys, followed by filtration for removal of sugars and the recovery of phenolics using methanol. The enriched extracts were evaluated for their chemical content (Total Phenolic Content, Total Flavonoid Content) and antioxidant properties (DPPH and ABTS methods). For the evaluation of their toxicity MTT and SRB assays were used. The extracts obtained from thyme honeys showed considerable phenolic content and significant antioxidant activity. The most promising honeys and enriched fractions were forwarded for the evaluation of their anti-mutagenic and anti-ageing activity.

HPTLC metabolic profiling and multivariate data analysis of the NMR spectra revealed a high variability in the content of the honey extracts. It is noteworthy that there are remarkable similarities between the samples derived from the same plant source, such as the honey produced by thyme and Chestnut tree, despite their different geographical origin. Indeed, the head space analysis based on solid-phase microextraction (SPME) technique revealed the presence of phenylacetaldehyde, thymoquinone, carvacrol, thymol, benzaldehyde and decanal as the main volatile constituents in the majority of thyme honey samples. However, there is a difficulty in categorizing multiflora honey samples.