## 4 Conclusions  
Rapid technological development, radiation exposure from natural or artificial sources, radiotherapy, medical imaging, etc., cause unintended toxicity and contribute to severe radiation-related pathologies. It is crucial to safeguard the biological system from such a barrage of detrimental effects from radiation. Scientific research has led to the creation of several synthetic chemicals to combat radiation's potential dangers. However, the need for alternative natural sources is vital due to its toxicity and adverse effects. In this report, methanolic extracts were obtained from freeze-dried kiwifruit and strawberries. Comparing both fruits, kiwifruit stood out for its vitamin C, ferulic acid, epicatech, and quercetin-3-O-galactoside content, and strawberry for its total phenol content, ellagic acid, pelargonidin-3-glucoside, quercetin-3-glucoside, and antioxidant activity. The freeze-drying process resulted in gains in the phenolic compounds of both samples and in the antioxidant activity of the kiwifruit. Then, the radioprotective effect of methanolic extracts from freeze-dried kiwifruit and strawberries against the damage induced by \(\gamma\)-irradiation in human peripheral blood lymphocytes was investigated. The results showed that kiwifruit methanolic extracts at concentrations of 400 and 800 \(\upmu\)g/mL possessed radioprotective ability, as evidenced by the significant reduction in the chromosomal aberration frequency after irradiation at a dose of 2 Gy. However, freeze-dried strawberry methanolic extracts did not reduce the damage caused by the effect of ionising radiation. None of the samples were found to exhibit genotoxic or cytotoxic effects. Although the free radical scavenging capacity of the extracts represents a possible mechanism for their radioprotective effect, it cannot be concluded that a greater antioxidant activity implies radioprotective power. The different responses of both fruits may indicate that radioprotection may be related to the different antioxidants present, such as vitamin C, and to the type of phenolic compound rather than to the amount of them, as their biological action depends on their chemical structure. Additionally, the synergistic effect between antioxidant substances must also be taken into account. Further investigation on radioprotection mechanisms is worth conducting in the future. Although potentially protective agents against harmful radiation have been investigated for decades, there is currently no ideal radioprotectant available. Therefore, it is very important that natural compounds with a potential radioprotective effect are studied for medical applications and in radiological and nuclear emergencies. The next step carried out by our research group will be in vivo studies. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app13158996/s1](https://www.mdpi.com/article/10.3390/app13158996/s1)]([https://www.mdpi.com/article/10.3390/app13158996/s1](https://www.mdpi.com/article/10.3390/app13158996/s1)), Figure S1: Metaphases with radioprotective and genotoxic biomarkers used in this study. Figure S2: Representative HPLC chromatogram of polyphenols of strawberries. (1) Pelargonidin-3-Glucoside, (2) quercetin-3-Glucoside, (3) ellagic acid. Conceptualisation, A.M. and E.G.-M.; methodology, N.S., A.M. and E.G.-M.; formal analysis, N.S., A.M. and E.G.-M.; data curation, M.d.S.R. ; writing--original draft preparation, N.S., A.M. and E.G.-M.; writing--review and editing, E.G.-M.; supervision, A.M. and E.G.-M.; project administration, A.M. and E.G.-M. All authors have read and agreed to the published version of the manuscript. This research was funded by Vicerrectorado de Investigacion, Universitat Politecnica de Valencia (UPV-FE-2013-56) (Spain). The study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of Hospital Universitario y Politecnico La Fe (date of approval: 4 April 2018) for studies involving humans.