Senapathy Giftson J, George Blassan P, Abrahamse Heidi
Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, Doornfontein, South Africa.
Anticancer Agents Med Chem. 2020;20(15):1831-1844. doi: 10.2174/1871520620666200703192127.
Cancer is still considered a deadly disease worldwide due to difficulties in diagnosis, painful treatment procedures, costly therapies, side effects, and cancer relapse. Cancer treatments using conventional methods like chemotherapy and radiotherapy were not convincing due to its post-treatment toxicity in the host. In Photodynamic Therapy (PDT), three individual non-toxic components including a photosensitizer, light source and oxygen cause damage to the cells and tissues when they are combined.
In recent years, phytochemicals are being increasingly recognized as potent complementary drugs for cancer because of its natural availability, less toxicity and therapeutic efficiency in par with commercial drugs. Hence, the idea of using phytochemicals as natural photosensitizers in PDT resulted in a multiple pool of research studies with promising results in preclinical and clinical investigations.
In this review, the potential of phytochemicals to act as natural photosensitizers for PDT, their mode of action, drawbacks, challenges and possible solutions are discussed in detail.
In PDT, natural photosensitizers, when used alone or in combination with other photosensitizers, induced cell death by apoptosis and necrosis, increased oxidative stress, altered cancer cell death signaling pathways, increased cytotoxicity and DNA damage in cancer cells. The pro-oxidant nature of certain antioxidant polyphenols, hormesis phenomenon, Warburg effect and DNA damaging potential plays a significant role in the photosensitizing mechanism of phytochemicals in PDT.
This review explores the role of phytochemicals that can act as photosensitizers alone or in combination with PDT and its mechanism of action on different cancers.
在全球范围内，癌症仍被视为一种致命疾病，这是由于其诊断困难、治疗过程痛苦、治疗费用高昂、存在副作用以及癌症复发等问题。使用化疗和放疗等传统方法进行癌症治疗，因其对宿主的治疗后毒性而未令人信服。在光动力疗法（PDT）中，三种单独无毒的成分，即光敏剂、光源和氧气，在组合时会对细胞和组织造成损伤。
近年来，植物化学物质因其天然可得性、低毒性以及与商业药物相当的治疗效果，越来越被视为癌症的有效辅助药物。因此，将植物化学物质用作PDT中的天然光敏剂这一想法引发了大量研究，在临床前和临床研究中取得了有前景的结果。
在本综述中，详细讨论了植物化学物质作为PDT天然光敏剂的潜力、其作用方式、缺点、挑战及可能的解决方案。
在PDT中，天然光敏剂单独使用或与其他光敏剂联合使用时，可通过凋亡和坏死诱导细胞死亡，增加氧化应激，改变癌细胞死亡信号通路，增加癌细胞的细胞毒性和DNA损伤。某些抗氧化多酚的促氧化性质、兴奋效应、瓦伯格效应和DNA损伤潜力在PDT中植物化学物质的光敏机制中起重要作用。
本综述探讨了植物化学物质单独或与PDT联合作为光敏剂的作用及其对不同癌症的作用机制。
