Bioactive components, antioxidant and antibacterial activities of different varieties of honey: a screening prior to clinical application.

This study assessed sixteen different honey samples in order to select the better one for therapeutic purposes. First, a study of honeys´ main bioactive compounds was carried out. Then phenolic profiles were determined and specific compounds quantified using a HPLC system coupled to a mass spectrometer. Then, antioxidant activity, by three in vitro methods, and antibacterial activity against reference strains and clinical isolates were evaluated. Great variability among samples was observed regarding ascorbic acid (between 0.34 ± 0.00 and 75.8 ± 0.41 mg/100 g honey; p<0.001), total phenolic compounds (between 23.1 ± 0.83 and 158 ± 5.37 mg/100 g honey; p<0.001) and total flavonoids contents (between 1.65 ± 0.11 and 5.93 ± 0.21 mg/100 g honey; p<0.001). Forty nine different phenolic compounds were detected, but only 46 of them were quantified by HPLC. The concentration of phenolic compounds and the phenolic profiles varied widely amongst samples (between 1.06 ± 0.04 and 18.6 ± 0.73 mg/100 g honey; p<0.001). Antioxidant activity also varied significantly between samples. All honey varieties exhibited antibacterial activity against both, reference and clinical strains (effective concentrations ranged between 0.05 and 0.40 g/mL depending on honey sample and bacteria tested). Overall, samples with better combination of bioactive properties were an avocado and a chestnut honey.