Background There are different treatments for breast cancer and melanoma that mostly have some side effects. One of the therapeutic strategies is the use of natural components. Phenol components are a class of antioxidants in plants that have many biological functions like anticancer effects. Gallic acid (GA) is a natural polyhydroxy phenolic compound and commonly found in various foods. In the present study, GA effects alone and in combination with low-level laser irradiation on human dermal fibroblast cell line (HDF), human non-tumorigenic breast epithelial cell line (MCF10A), breast cancer cell line (MDA-MB-231) and melanoma cancer cell line (A375) was under the investigation. Methods The normal and cancerous cell lines were exposed to 660 nm low-level laser with 3 J/cm2 for 90 s. Then, the cells were treated with different concentrations of GA for 24 h. In another study, the cell lines firstly were treated with GA and then exposed to low-level laser irradiation. The effects of GA and low-level laser on cell survival and apoptosis were examined using MTT assay, light microscopy, ROS production assay, fluorescence microscopy (AO/EB double staining) and flow cytometry. Results The results showed that pre-treatment with low-level laser and then GA reduced the survival of breast cancer cells and melanoma more than the first treatment with GA and then low-level laser irradiation. Our findings showed that ROS production in cells treated with both low-level laser and GA was more than the cells treated with GA alone. The apoptosis and ferroptosis assays confirmed the MTT results which combination treatment with low-level laser and then GA increase the cell death probably via apoptosis and ferroptosis cell death mechanisms compared to GA alone. Conclusions This study suggests that low-level laser irradiation alone is not able to cause death in human normal and cancerous cells. Preirradiation followed by GA treatment did not change the cell viability in human normal significantly but reduces the cell survival of cancer cells more than GA alone.

中文翻译：

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低水平激光照射下没食子酸的抗癌作用：ROS的产生以及细胞凋亡和铁死亡的诱导。


背景 乳腺癌和黑色素瘤有不同的治疗方法，但大多都有一些副作用。治疗策略之一是使用天然成分。苯酚成分是植物中的一类抗氧化剂，具有抗癌等多种生物学功能。没食子酸（GA）是一种天然多羟基酚化合物，常见于各种食品中。在本研究中，GA单独或与低强度激光照射联合对人真皮成纤维细胞系（HDF）、人非致瘤性乳腺上皮细胞系（MCF10A）、乳腺癌细胞系（MDA-MB-231）产生影响黑色素瘤癌细胞系（A375）正在研究中。方法将正常细胞系和癌细胞系暴露于660 nm低强度激光、3 J/cm2下90 s。然后，用不同浓度的GA处理细胞24小时。在另一项研究中，细胞系首先用 GA 处理，然后暴露于低强度激光照射。使用MTT测定、光学显微镜、ROS产生测定、荧光显微镜（AO/EB双染色）和流式细胞术检查GA和低强度激光对细胞存活和凋亡的影响。结果 结果显示，先用低强度激光治疗，然后进行 GA 比先用 GA 治疗，然后进行低强度激光照射，更能降低乳腺癌细胞和黑色素瘤的存活率。我们的研究结果表明，同时用低强度激光和 GA 处理的细胞中 ROS 的产生量比单独用 GA 处理的细胞要多。细胞凋亡和铁死亡测定证实了MTT结果，与单独使用GA相比，结合低强度激光和GA治疗可能通过细胞凋亡和铁死亡细胞死亡机制增加了细胞死亡。 结论 这项研究表明，单独的低强度激光照射不能导致人类正常细胞和癌细胞死亡。预照射后进行 GA 处理不会显着改变人类正常细胞的活力，但比单独使用 GA 更能降低癌细胞的细胞存活率。