Phenolic Compounds and Bioactivity of Cytisus villosus Pourr.

The present study focuses on the chemical composition, antioxidant, antimicrobial, and antiproliferative activities of the ethyl acetate and aqueous extracts obtained from the aerial parts of <i>Cytisus villosus</i> Pourr. HPLC-DAD-ESI/MSn was used to identify the phenolic compounds, being (epi)gallocatechin dimer the major compound (111 ± 5 µg/g·dw) in the aqueous extract, while myricetin-<i>O</i>-rhamnoside (226 ± 9 µg/g·dw) was the main molecule in the ethyl acetate extract. Both extracts exhibited good scavenging activities against DPPH radical (EC₅₀ µg/mL of 59 ± 2 and 31 ± 2 for aqueous and ethyl acetate extracts, respectively). However, the ethyl acetate extract demonstrated more potent quenching activities than the aqueous extract. The antimicrobial activities were assessed on selected Gram-positive (<i>Staphylococcus epidermidis</i>) and Gram-negative (<i>Escherichia coli</i> and <i>Pseudomonas aeruginosa</i>) bacteria, as well as on pathogenic fungus <i>Candida glabrata</i>. The extracts possessed selective and potent antimicrobial activities against the Gram-positive bacterium (IC₅₀ of 186 ± 9 μg/mL and 92 ± 3 μg/mL for aqueous and ethyl acetate extracts, respectively). Finally, <i>C. villosus</i> extracts were evaluated for their antiproliferative potential on three human cancer cell lines representing breast and colon cancers. Although both extracts demonstrated sufficient growth inhibition of the three different cell lines, the ethyl acetate extract exhibited higher activity (LD₅₀ values of 1.57 ± 0.06 mg/mL, 2.2 ± 0.1 mg/mL, and 3.2 ± 0.2 mg/mL for T47D, MCF-7, and HCT-116 cell lines). Both the extracts obtained from the aerial parts of <i>C. villosus</i> revealed very promising results and could be applied as functional agents in the food, pharmaceutical, and cosmeceutical industries.