Infrared Spectroscopy Laboratory, Research and Development Institute R&DI, University of Vale do Paraíba - Univap, Shishima Hifumi Avenue, 2911, São Jose dos Campos, São Paulo, 12244-000, Brazil.
Sir John Walsh Research Institute, 310 Great King Street, Dunedin, 9016, New Zealand.
Lasers Med Sci. 2021 Jun;36(4):821-827. doi: 10.1007/s10103-020-03110-2. Epub 2020 Aug 3.
Photodynamic therapy (PDT) with photosensitizer methylene blue was applied to Leishmania braziliensis, and Fourier transform infrared (FTIR) spectroscopy was used to study biochemical changes in the parasite after PDT in comparison to untreated (C), only irradiation (I), and only photosensitizer (PS). Spectral analysis suggests increase in lipids, proteins, and protein secondary structures in PDT compared with C and decrease in nucleic acids and carbohydrates. Interestingly, these trends are different from PDT of Leishmania major species, wherein lipids decrease; there are minimal changes in secondary structures and increase in nucleic acids and carbohydrates. The study thus suggests possibility of different biomolecular players/pathways in PDT-induced death of L. braziliensis and L. major.
光动力疗法（PDT）用光敏剂亚甲蓝处理巴西利什曼原虫，傅里叶变换红外（FTIR）光谱用于研究 PDT 后寄生虫的生化变化，与未经处理（C）、仅照射（I）和仅光敏剂（PS）的对照。光谱分析表明，与 C 和核酸及碳水化合物相比，PDT 中脂质、蛋白质和蛋白质二级结构增加。有趣的是，这些趋势与利什曼原虫物种的 PDT 不同，其中脂质减少；二级结构变化最小，核酸和碳水化合物增加。因此，该研究表明在 PDT 诱导的巴西利什曼原虫和利什曼原虫死亡中可能存在不同的生物分子参与者/途径。
