Hydroxypropyl-β-Cyclodextrin-Based Helichrysum italicum Extracts: Antioxidant and Cosmeceutical Activity and Biocompatibility.

Two Helichrysum italicum extracts, OPT-1 (rich in phenolic acids) and OPT-2 (rich in total phenols and flavonoids), were prepared using hydroxypropyl-β-cyclodextrin (HP-β-CD)-assisted extraction. The prepared extracts were rich in phenolic compounds, including flavonoids and phenolic acids. GC-MS analysis of the extracts identified neryl acetate, neo-intermedeol, β-selinene, γ-curcumene, italidione I, and nerol as the main volatile components of the extracts, as well as plant sterols, γ-sitosterol, campesterol, and stigmasterol. The antioxidant (DPPH radical scavenging, reducing power, and a carotene linoleic acid assay) and cosmeceutical (anti-hyaluronidase, anti-tyrosinase, anti-lipoxygenase, ovalbumin anti-coagulation, and a UV-absorption assay) activity of the extracts in most of the assays was better than the activity of the applied positive controls. Especially low were the IC 50 values of the extracts in the anti-hyaluronidase (14.31 ± 0.29 μL extract/mL and 19.82 ± 1.53 μL extract/mL for OPT-1 and OPT-2, respectively) and the anti-lipoxygenase (0.96 ± 0.11 μL extract/mL and 1.07 ± 0.01 μL extract/mL for OPT-1 and OPT-2, respectively) assays. The extracts were non-toxic to HaCaT cells in concentrations of up to 62.5 µL extract/mL assuring their status as excellent candidates for cosmeceutical product development appropriate for direct use in cosmetic products without solvent evaporation.