Protolichesterinic acid enhances doxorubicin-induced apoptosis in HeLa cells in vitro.

Aim: The aim of this study was to investigate the effect of protolichesterinic acid, a lichen secondary metabolite, on anti-proliferative activity of doxorubicin in three human cancer cell lines, HeLa, SH-SY5Y and K562 cells.

Main Methods: The data obtained from MTT assays, performed on cells treated with protolichesterinic acid and doxorubicin alone and in combination, were analysed by the median-effect method as proposed by Chou and Talalay and the Bliss independence model. Apoptosis rate was evaluated by fluorescence microscopy, caspase-3, 8 and 9 activities were detected by spectrofluorimetric analysis and protein expression of Bim, Bid, Bax and Mcl-2 was analysed by Western blotting.

Cytotoxic activity and antioxidant capacity of purified lichen metabolites: an in vitro study.

The purpose of this study was to investigate the effects of six lichen metabolites (diffractaic acid, lobaric acid, usnic acid, vicanicin, variolaric acid, protolichesterinic acid) on proliferation, viability and reactive oxygen species (ROS) level towards three human cancer cell lines, MCF-7 (breast adenocarcinoma), HeLa (cervix adenocarcinoma) and HCT-116 (colon carcinoma). Cells were treated with different concentrations (2.5-100 μM) of these compounds for 48 h.