Light Power Of Natural Antioxidants Therapy

Photodynamic therapy (PDT) is a treatment for cancer and certain non-malignant pathologies that is generally characterized by overgrowth of unwanted or abnormal cells. It includes loading of the target cells with a photosensitizer and subsequent illumination with visible light. When the oxygen existence, the combination of light and photosensitizer causes generation of reactive oxygen species (ROS), in particular singlet oxygen, superoxide anion and hydroxyl radical, resulting in target cell death either through necrosis or apoptosis. Direct and indirect evidence supports a prevalent role for singlet oxygen in the molecular processes initiated by PDT.Natural antioxidants have antioxidant properties and it was popular in diet and medicine. Owing to natural antioxidants were potential anticancer drug, PDT and natural antioxidants were likely use in cancer therapy at same time. It must be noticed that any antioxidant found to reduce toxicity of tumor therapy on healthy tissue has the potential to decrease effectiveness of cancer therapy on malignant cells. Therefore, study the influence of natural antioxidants on PDT is very significant.This research mainly studies the influence of natural antioxidants on PDT.Conclusions got from experiments as follows:1. Genistein inhibits K562 cells proliferation. Supplementation of genistein in K562 cells increases the lipid peroxidation, DNA damage, and decreases the survival rate in PDT treatment.2. Daidzein inhibits K562 cells proliferation. It couldn't increase cells death, the lipid peroxidation and cell apoptosis in ALA-PDT.3. Formononetin couldn't inhibit K562 cells proliferation. Supplementation of formononetin in K562 cells increases the lipid peroxidation, DNA damage, and decreases the survival rate in PDT treatment.4. Ellagic acid inhibits K562 cells proliferation. Supplementation of 1OOμM ellagic acid in K562 cells increases the lipid peroxidation, DNA damage, and decreases the survival rate in PDT treatment.5. Mangostin inhibits K562 cells proliferation. It enhanced cells death after incubating 24h in a dose-dependent manner when undergoing PDT treatment. Supplementation of mangostin in K562 cells increases the lipid peroxidation, DNA damage, and decreases the survival rate after incubating 24h in PDT treatment.6. These results implied that the effect of antioxidants on PDT may depend on its sensitization ability to singlet oxygen. The innovations of the dissertation:The combine of the effects of anti-oxidant in cancer therapy and PDT was not be studied by any researcher. The present paper studied this firstly.