Anticancer activity of a quercetin-based polymer towards HeLa cancer cells.

BACKGROUND Quercetin is one of the most potent antioxidants showing anti-inflammatory, antiproliferative and antitumoral effects; however its short half-life in buffered solution (e.g. body fluids) has so far hampered its introduction into clinical practice. AIM To overcome this inconvenience, quercetin was covalently conjugated into a polymethacrylic acid backbone and the conjugate was tested on HeLa cancer cells. MATERIALS AND METHODS FT-IR, UV-Vis, Gel Permeation Chromatography analyses and the Folin-Ciocalteu test were performed to characterize the conjugate. Antioxidant properties were assessed by the DPPH test and the viability experiments by trypan blue exclusion assay. RESULTS The conjugate showed a functionalization degree of 2.01 mg of Q per g, an IC(50) of 2.62 mg ml(-1) in the DPPH assay and was able to induce a 90% cell death after one day treatment, while the value for free Quercetin was 40% after three days. CONCLUSION Polymer conjugation significantly increases quercetin stability, leading to a sustained activity of the flavonoid.