Anti-Obesity Effect of Chlorin e6-Mediated Photodynamic Therapy on Mice with High-Fat-Diet-Induced Obesity

This study aimed to evaluate the efficacy of Chlorin e6 (Ce6)-based photodynamic therapy (PDT) for anti-obesity activities in high-fat-diet (HFD)-induced obesity mouse models. We induced obesity in C57BL/6 mice by HFD and administered Ce6 (2.5 or 5 mg/kg) orally with 3 h of incubation. The mice were then exposed to light of high fluence rate (4.96 mW/cm(2)) or low fluence rate (2.56 mW/cm(2)) in the designed LED mouse chamber 2-3 days a week for up to 8 weeks. The study also analyzed the pharmacokinetics and optimization of the drug by evaluating the absorption, distribution, metabolism, and excretion (ADME) of Ce6 in the rat models. Both low doses (2.5 mg/kg) and high doses (5 mg/kg) of Ce6 with high irradiation dose showed better anti-obesity effects than other groups with decreased body weight. The lipid accumulation in the liver and adipocyte size in epididymal adipose tissues were found to be decreased by Ce6-PDT in comparison to vehicle-treated HFD groups. We also observed increased levels of the lipidomic biomarkers, such as leptin and LDL cholesterol, while observing decreasing levels of total cholesterol and adiponectin in the Ce6-PDT-treated mice. These findings may provide valuable insight into Ce6-PDT as an alternative and non-invasive therapeutic methodology for obesity and obesity-related diseases.