The Anti-Cancer Efficacies of Diffractaic, Lobaric, and Usnic Acid: in Vitro Inhibition of Glioma

Abstract

Aims: Glioblastoma multiforme (GBM) shows the most aggressive invasion among primary brain tumors. In spite of the standard therapy methods such as surgery, radiotherapy, and chemotherapy, the mortalities are high in GBM patients owing to side effects. Some lichen secondary metabolites that have many bioactive functions exhibited anti-cancer efficacy toward many cancer types. The present study was undertaken to investigate proliferation change, oxidative status and DNA damage potentials of human U87MG-GBM, and primary rat cerebral cortex (PRCC) cells exposed to three lichen secondary metabolites. Materials and Methods: Different concentrations of lichen secondary metabolites including diffractaic acid (DA), lobaric acid (LA), and (+)-usnic acid (UA) were used for the treatments. PRCC cells were obtained from Sprague Dawley (R) rats. U87MG cell line was preferred as GBM cells. Results: The results showed that lactate dehydrogenase and 8-hydroxy-2'-deoxyguanosine levels increased in PRCC and U87MG cells in a clear dose-dependent manner. Inhibitory concentration 50% (IC50) values of LA, DA, and UA were calculated as 9.08, 122.26, 132.69 mg/L for PRCC cells and 5.77, 35.67, 41.55 mg/L for U87MG cells, respectively. Concentration of 10 mg/L of DA and UA demonstrated high anti-oxidant capacity on healthy PRCC cells. Conclusions: Overall, obtained data indicated that LA was highly toxic on GBM and PRCC cells. However, DA and then UA had high anti-oxidant capacity on PRCC cells. These results suggest that further studies that will be held on LA may play a critical role in GBM treatment.