Al-Awaida Wajdy, Al-Ameer Hamzeh J, Sharab Ahmad, Akasheh Rand T
Department of Biology and Biotechnology, Faculty of Science, American University of Madaba, P.O. Box: 99, Madaba 17110, Jordan.
Department of Pharmaceutical Biotechnology, Faculty of Allied Medical Sciences, Al-AhliyyaAmman University (AAU), Amman, 19328, Jordan.
Curr Res Toxicol. 2023 Sep 19;5:100127. doi: 10.1016/j.crtox.2023.100127. eCollection 2023.
This study scrutinizes the effects of simulated microgravity on the antioxidant and cytotoxic potential, along with the phytochemical content of wheatgrass (). To imitate microgravity, wheatgrass seeds were germinated in a 3D-clinostat at different rotations per minute (5, 10, 15, and 20 rpm), together with terrestrial gravity control, over 10 days. After germination, the methanolic extracts were analyzed using UPLC-Triple Quad LCMS for their phytochemical composition and tested for their hydrogen peroxide, nitric oxide, and DPPH scavenging activities. The cytotoxic effects of these extracts were evaluated against normal skin fibroblasts, normal breast cells (MCF-10), and breast cancer cells (MCF-7 and MDA-231). The findings showed an extended root growth in wheatgrass germinated under microgravity (WGM) compared to under gravity (WGG). Additionally, WGM extracts demonstrated increased H2O2-, NO-, and DPPH-scavenging activities and a higher content of polyphenols and flavonoids than WGG extracts. These effects were amplified with an increase in clinostat rotations. Moreover, WGM extracts were found to contain a unique set of bioactive compounds (compounds that were detected in the microgravity-germinated wheatgrass but were either absent or present in lower concentrations in wheatgrass germinated under standard gravity conditions.), including pyridoxine, apigenin, and tocopherol, among others, which were absent in WGG. The UPLC-Triple Quad LCMS analysis revealed these unique bioactive compounds in WGM. Notably, WGM extracts showed enhanced cytotoxic effects against normal skin fibroblasts, normal MCF-10, MCF-7, and breast cancer MDA-231 cell lines, with increased cytotoxicity correlating with the number of clinostat rotations. Particularly, WGM extract (at 20 rpm) demonstrated significantly stronger cytotoxicity against MCF-7 breast cancer cells. Further in-depth gene expression analysis of MCF-7 cells exposed to WGM revealed a significant downregulation of genes integral to breast cancer pathways, tyrosine kinase signaling, and DNA repair, complemented by upregulation of certain cell survival and cytotoxic genes. These alterations in genetic pathways associated with cell survival, hormone responses, and cancer progression may elucidate the enhanced cytotoxicity observed in WGM extracts. Our findings underscore the potential of microgravity as a tool to enhance the cytotoxic capabilities of wheatgrass against cancer cell lines, presenting a promising direction for future research in the field of space biology and its implications for terrestrial health.
本研究详细考察了模拟微重力对小麦草抗氧化和细胞毒性潜力以及植物化学成分的影响。为模拟微重力环境，将小麦草种子在三维回转器中以不同的每分钟转速（5、10、15和20转）进行萌发，同时设置地面重力对照组，持续10天。萌发后，采用超高效液相色谱-三重四极杆液相色谱-质谱联用仪（UPLC-Triple Quad LCMS）分析甲醇提取物的植物化学成分，并检测其对过氧化氢、一氧化氮和二苯基苦味酰基自由基（DPPH）的清除活性。评估这些提取物对正常皮肤成纤维细胞、正常乳腺细胞（MCF-10）和乳腺癌细胞（MCF-7和MDA-231）的细胞毒性作用。研究结果表明，与重力条件下萌发的小麦草（WGG）相比，微重力条件下萌发的小麦草（WGM）根系生长更长。此外，WGM提取物对过氧化氢、一氧化氮和DPPH的清除活性增强，且多酚和黄酮类化合物含量高于WGG提取物。随着回转器转速的增加，这些效应更加明显。此外，发现WGM提取物含有一组独特的生物活性化合物（在微重力萌发的小麦草中检测到，但在标准重力条件下萌发的小麦草中不存在或含量较低的化合物），包括吡哆醇、芹菜素和生育酚等，而WGG中不存在这些化合物。UPLC-Triple Quad LCMS分析揭示了WGM中这些独特的生物活性化合物。值得注意的是，WGM提取物对正常皮肤成纤维细胞、正常MCF-10、MCF-7和乳腺癌MDA-231细胞系的细胞毒性作用增强，细胞毒性增加与回转器转速相关。特别是，WGM提取物（20转/分钟）对MCF-7乳腺癌细胞的细胞毒性显著更强。对暴露于WGM的MCF-7细胞进行进一步深入的基因表达分析发现，乳腺癌相关通路、酪氨酸激酶信号传导和DNA修复相关基因显著下调，同时某些细胞存活和细胞毒性基因上调。这些与细胞存活、激素反应和癌症进展相关的基因通路改变可能解释了WGM提取物中观察到的增强的细胞毒性。我们的研究结果强调了微重力作为一种增强小麦草对癌细胞系细胞毒性能力的工具的潜力，为空间生物学领域的未来研究及其对地球健康的影响提供了一个有前景的方向。
