Echium plantagineum L. honey: Search of pyrrolizidine alkaloids and polyphenols, anti-inflammatory potential and cytotoxicity

For a long time, honey has been recognized for its health-promoting properties and, consequently, has been used in traditional medicine worldwide. Apart from the beneficial bioactive compounds found in this food (e.g. polyphenols), molecules with potentially harmful effects may also be present, such as pyrrolizidine alkaloids. Aiming the quality assessment of honeys produced from Echium plantagineum L., a species known for its content in pyrrolizidine alkaloids, this work was focused in the search of these alkaloids and of polyphenols in one monofloral and two multifloral honeys, using chromatographic techniques. Additionally, their cytotoxicity and anti-inflammatory potential were assessed in cellular models. Several polyphenols were determined, but no pyrrolizidine alkaloid was detected in the analysed honey samples. Honey extracts exhibited capacity to decrease NO levels in lipopolysaccharide-stimulated murine macrophage-like cells (RAW 264.7) up to 40% at concentrations of 0.25 mg/mL. Therefore, this work highlights the health benefits of these honey samples.