Treatment of olive vegetation waste with tyrosinase immobilized on multiwalled carbon nanotubes increased the antioxidant activity as a consequence of the conversion of phenols to corresponding catechol derivatives, as evaluated by DPPH, Comet assay, and micronucleus analyses. During this transformation, 4-hydroxyphenethyl alcohol (tyrosol) was quantitatively converted to bioactive 3,4-dihydroxyphenethyl alcohol (hydroxytyrosol). The hydroxytyrosol-enriched olive vegetation waste also promoted autophagy and inhibited the inflammatory response in human THP-1 monocytes.
Keywords: antioxidant activity; autophagy; cytokines; hydroxytyrosol; inflammation; olive vegetation waste; recovery of valuable substances; tyrosinase bioconversion.