Interaction of aminophylline with photoilluminated riboflavin leads to ROS mediated macromolecular damage and cell death in benzopyrene induced mice lung carcinoma.

Riboflavin (Rf) or vitamin B₂ is a known photosensitizer whose photophysical and photochemical properties are well established. Aminophylline (Am) is a phosphodiesterase inhibitor and is currently used as a bronchodilator. Although there are several reports of haemolytic and proteolytic interaction of photoilluminated riboflavin with aminophylline, the cytotoxicity of this system against malignant tissue is not well defined and fully unravelled. Here, we are evaluating anticancer activity of this system against B(a)P induced lung carcinoma in swiss albino mice. We observed marked increment in the level of cellular redox scavengers as well as oxidative stress markers. A significant DNA damage was observed using comet assay. Histopathological studies further confirmed induction of apoptosis in lung tissues of Am-Rf treated animals. Scanning electron microscopy revealed altered surface morphology of the malignant tissue, which characteristically improved in the treatment group. Since malignancy is characterised by compromised redox status, therefore, further increment in ROS due to the action of this system derives cellular system towards extensive macromolecular damage and consequent ROS mediated apoptosis. We anticipate the usage of this system in developing efficient photodynamic therapy against lung cancer that can be clinically realised.