Evaluation of trihydroxyflavones anticancer activity

Aim of this research: To evaluate anticancer activity of trihydroxyflavones. Objectives: 1) To evaluate the effect of trihydroxyflavones on human cancer cell viability in vitro; 2) To evaluate the effect of trihydroxyflavones on human cancer cell migration in vitro; 3) To determine the antioxidant activity of trihydroxyflavones using DPPH method; 4) To evaluate structure – activity relationship of trihydroxyflavones; 5) To evaluate the correlation between cell viability and antioxidant activity of trihydroxyflavones. Methods. The effect on cancer cell viability was tested using MTT method. Cell migration assay was performed using „wound healing“ technique. Antioxidant activity was evaluated by using DPPH free radical binding method. The correlation between antioxidant and anticancer activity was assesed by calculating Pearson`s coefficient and its statistical reliability. Results. Thirteen out of seventeen tested trihydroxyflavones possessed anticancer activity against at least one of tested cancer cell lines. The most active anticancer compound was 5,3‘,4‘-trihydroxyflavone against breast (MCF7) and lung adenocarcinoma (A549) cancer cell lines with EC50 values 6,8 ± 0,6 µM and 11,2 ± 1,1 µM, respectively. Apigenin and baicalein were not the most active proliferation inhibitors, they were not active against U87 cancer cell line. 6,3`,4`- trihydroxyflavone was the most active compound against A549 cell migration. 3,3`,4`-trihydroxyflavone possessed the best antioxidant properties (EC50 = 10.5 µM). Most of the tested compouds possessed antioxidant activity comparable to that of trolox. The anticancer and antioxidant trihydroxyflavone activity was related mostly to ortho-dihydroxy structural fragment in ring B. An average correlation was determined between the effect on A549 and U87 cell viability and free radical scavenging properties of trihydroxyflavones. Conclusions. Trihydroxyflavones inhibit MCF7 and A549 cell proliferation, they have lower effect on U87 cell viability. They possess very low effect on U87 and A549 cell migration. Most of tested trihydroxyflavones revealed to have a free radical scavenging activity, some of them were 3.5 times more active than trolox. The anticancer activity of trihydroxyflavones against A549 and U87 cells could be related to their antioxidant activity