Polyphenols Extracted from Artemisia annua L. Exhibit Anti-Cancer Effects on Radio-Resistant MDA-MB-231 Human Breast Cancer Cells by Suppressing Stem Cell Phenotype, ß-Catenin, and MMP-9.

Artemisia annua L. has been reported to show anti-cancer activities. Here, we determined whether polyphenols extracted from Artemisia annua L. (pKAL) exhibit anti-cancer effects on radio-resistant MDA-MB-231 human breast cancer cells (RT-R-MDA-MB-231 cells), and further explored their molecular mechanisms. Cell viability assay and colony-forming assay revealed that pKAL inhibited cell proliferation on both parental and RT-R-MDA-MB-231 cells in a dose-dependent manner. The anti-proliferative effects of pKAL on RT-R-MDA-MB-231 cells were superior or similar to those on parental ones. Western blot analysis revealed that expressions of cluster of differentiation 44 (CD44) and Oct 3/4, matrix metalloproteinase-9 (MMP-9) and signal transducer and activator of transcription-3 (STAT-3) phosphorylation were significantly increased in RT-R-MDA-MB-231 cells compared to parental ones, suggesting that these proteins could be associated with RT resistance. pKAL inhibited the expression of CD44 and Oct 3/4 (CSC markers), and ß-catenin and MMP-9 as well as STAT-3 phosphorylation of RT-R-MDA-MB-231. Regarding upstream signaling, the JNK or JAK2 inhibitor could inhibit STAT-3 activation in RT-R-MDA-MB-231 cells, but not augmented pKAL-induced anti-cancer effects. These findings suggest that c-Jun N-terminal kinase (JNK) or Janus kinase 2 (JAK2)/STAT3 signaling are not closely related to the anti-cancer effects of pKAL. In conclusion, this study suggests that pKAL exhibit anti-cancer effects on RT-R-MDA-MB-231 cells by suppressing CD44 and Oct 3/4, ß-catenin and MMP-9, which appeared to be linked to RT resistance of RT-R-MDA-MB-231 cells.

Anthocyanins from black soybean seed coat prevent radiation-induced skin fibrosis by downregulating TGF-ß and Smad3 expression.

The aim of this study was to evaluate the protective effects of anthocyanins from the black soybean seed coat against radiation injury in dermal fibroblasts and mouse skin. Dermal fibroblasts treated with 50 and 100 µg/mL anthocyanins were irradiated with single doses of 20 Gy. Cell viability, intracellular reactive oxygen species (ROS) production, and mRNA expression were measured. A total of 60 mice were used for an in vivo study. A dose of 100 µg/mL anthocyanins was administered daily for 5 days before or after radiation therapy. Following irradiation (45 Gy), mice were inspected for gross pathology twice per wk for 8 weeks. At 4 and 8 weeks post-irradiation, dorsal skin was harvested for histopathologic examination and protein isolation. In dermal fibroblasts, treatment with 50 and 100 µg/mL anthocyanins significantly reduced radiation-induced apoptosis at 72 h and intracellular reactive oxygen species generation at 48 h. Furthermore, 100 µg/mL anthocyanins markedly decreased Smad3 mRNA expression and increased Smad7 mRNA expression at 72 h post-irradiation. In mice, treatment with 100 µg/mL anthocyanins resulted in a significant reduction in the level of skin injury, epidermal thickness, and collagen deposition after irradiation. Treatment with 100 µg/mL anthocyanins significantly decreased the number of α-SMA-, TGF-ß-, and Smad3-positive cells after irradiation. Our study demonstrated that black soybean anthocyanins inhibited radiation-induced fibrosis by downregulating TGF-ß and Smad3 expression. Therefore, anthocyanins may be a safe and effective candidate for the prevention of radiation-induced skin fibrosis.