Combination therapy enhanced the antitumor activity of artemisinin-iron in lung cancer Calu-6 cells

Abstract

Aim of Study: Combination therapy has become an important strategy for treatment of cancer and enhancing response rates. Artemisinin, a derivative from Artemisia annua, is a well-known potent antitumor component. Iron is considered as an essential component in the cytotoxicity of artemisinin. Butyric acid and miconazole both are shown to induce apoptosis in several cancer cell lines. The present study investigated the potential enhanced antitumor activity of artemisinin-iron on lung cancer adenocarcinoma cell line (Calu-6) when it is combined with butyric acid and/or miconazole. Materials and Methods:  Cultured Calu-6 cells were divided into 12 flasks. The cells were treated with different doses of artemisinin (0.15, 0.3, 0.6 and 1.2 µg/ml) and iron (1 µmol/ml) with and without constant dose of butyric acid (55 µmol/ml) and/or miconazole (3 µmol/ml). The cells were monitored and photographed every 12 hours using an inverted microscope. After 60 hours, supernatants and cell extracts were examined for LDH (lactate dehydrogenase) concentration and total protein. Cell extract was examined for thiobarbituric acid-reactive substances (TBARS). Hematoxylin-eosin stained slides were prepared for microscopic examinations. Results: Biochemical analysis of artemisinin-iron treated cells revealed cell injury and reaction in a dose dependent manner. Concurrent combination of butyric acid and miconazole with artemisinin-iron caused significant increase in LDH concentration and TBARS when compared with the control group. Morphological changes include cell and nuclear swelling, vacuole formation, cellular detachment, pyknosis, karyolysis, necrosis and inhibition of new mitosis. Conclusion: Although artemisinin renders an excellent antitumor activity, its combination with butyric acid and miconazole provides a safe potent anticancer agent.