The Shrub of the Future
By Eliane Grace
When you think about protecting yourself from harmful radiation, shrubs might be the last thing that comes to mind. However, Tiju Chacko and his fellow researchers from the University of Oxford have found that an extract from the shrub Clerodendron infortunatum (CIE) can offer protection from gamma radiation1,a form of high frequency electromagnetic radiation2. Negative effects of gamma radiation include DNA damage and significantly reduced blood cell counts, which could potentially lead to cancer in some instances. Despite the risks of radiation exposure, gamma radiation continues to be applied in industry, healthcare, power production, and many other sectors, thereby increasing the general population’s risk of being exposed to radiation1. Due to the inevitability of people being exposed to gamma radiation at some point, it is important to develop a way for people to protect themselves. Luckily,based on the results of Chacko et al’s study on shrubs, a reliable form of protection might not be so far away.
In Chacko et al’s study, the CIE was orally administered to mice to determine the extent to which the shrub could prevent harmful damage from gamma radiation. Two control groups of mice did not receive any gamma radiation or CIE, and another group received radiation but no extract. The remaining seven groups of mice received varying amounts of extract and radiation. After radiation exposure, the mice in groups one through five were ‘sacrificed’ at staggered times over 24 hours so that bone marrow and blood cells could be analyzed in addition to other types of data. Mice in groups 6 through 10 were not sacrificed, and their survival rates were recorded.1
One of the tests performed on the bone marrow and blood cells was a procedure known as alkaline single-cell gel electrophoresis, also called a “comet assay.”1 This test is commonly used to determine DNA damage to single cells. The data had a decreased comet parameter, indicating that the oral administration of CIE to mice was able to protect them from radiation-induced DNA strand breaks1. Furthermore, although many of the mice were exposed to amounts of radiation that should have killed them, their survival rates increased with higher concentrations of CIE.
The results of Chacko et al’s experiment indicate that the oral administration of CIE can reduce cellular damage and increase the survival rate of mice exposed to gamma radiation. Although it is not guaranteed that CIEcan protect people from radiation as it does in mice, several similarities between mice and humans raise the possibility that the extract can be used on humans sometime in the future: Both the mouse and human genomes contain a similar number of base pairs (approximately 3.1 billion), and out of the 4,000 studied genes, more than 3,990 of them are found in both species4. Due to this significant genetic similarity, harmful mutations in human DNA–many of which can be caused by radiation– can be reliably recreated in mice in order to safely study the effects of these alterations.
The results of Chacko et al’s study are significant for future development of protection from radiation.
1. Chacko, Tiju, et al. “Mitigation of whole-body gamma radiation–induced damages by Clerodendron infortunatum in mammalian organisms.” Journal of Radiation Research, vol 58, no. 3. Oxford University Press, 18 Nov. 2016. https://doi.org/10.1093/jrr/rrw093
2. “What are x-rays and gamma rays?” American Cancer Society. 2017. 8 Jul. 2017. https://www.cancer.org/cancer/cancer-causes/radiation-exposure/x-rays-gamma-rays/what-are-xrays-and-gamma-rays.html
3. Mclean, Virginia. “Gray (Gy).” Health Physics Society. 8 Jul. 2017. http://hps.org/publicinformation/radterms/radfact79.html
4. Why Mouse Matters.” NIH National Human Genome Research Institute. 23 Jul. 2010.