Abstract Summary/Description
The study examines two naphthoquinone compounds with similar structures but differing toxicities, menadione and plumbagin. Menadione is a synthetic derivative of Vitamin K, while plumbagin is a plant-derived toxin used in homeopathic medicine for its beneficial qualities. Both compounds have demonstrated anti-cancer ability and the ability to produce reactive oxygen species (ROS), but it is unclear from current literature what causes the differences in toxicity. It was hypothesized that plumbagin may produce relatively more ROS or more potent ROS when compared to menadione under various conditions, thus leading to increased toxicity. The study aims to characterize these compounds by examining their ability to cleave DNA and produce ROS. Menadione did not produce significant chemical cleavage under any conditions studied, while plumbagin does at 1 mM with 1 mM sodium ascorbate. Photocleavage showed the opposite effect, with menadione producing more cleavage compared to plumbagin, with an average of 83% and 45% respectively. An ROS probe assay utilizing a fluorescence microplate reader and fluorescein standard was developed for use in this study based on previous literature. Menadione and plumbagin have been examined for hydroxyl radical production using the ROS fluorescent probe HPF. The assay revealed that both compounds produce hydroxyl radicals in a concentration-dependent manner, which could explain the results from photocleavage experiments. Similar analyses will be performed to examine other ROS probes such as Singlet Oxygen Sensor Green. Both compounds will also be examined for differences in DNA cleavage and ROS production in vivo using E. coli.
