Environmental and Molecular Mutagenesis 00:00^00 (2017) Letter to the Editor Comments on “Sesamol Ameliorates Radiation Induced DNA Damage in Hematopoietic System of Whole Body c-Irradiated Mice” S. M. J. Mortazavi * Diagnostic Imaging Center, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111 This letter is regarding the concerns about the article entitled “Sesamol ameliorates radiation induced DNA damage in hematopoietic system of whole body girradiated mice” by Kumar et al. published in the Environ Mol Mutagen [Kumar et al., 2017]. Despite its strengths, the paper authored by Kumar et al. has at least one major and some minor shortcomings. A major shortcoming of this paper comes from ignoring this cardinal point that without knowing the optimum dose of different radioprotectors, comparison of their effects at specific doses is nonsense. For example, the authors have compared the radioprotective effect of sesamol (20 mg/kg) with that of amifostin (20 mg/kg). It is worth noting that the amifostin doses used by other researchers is much higher [167 [Liu et al., 2015], 200 [Akbulut et al., 2014; Liu et al., 2015; Yurut-Caloglu et al., 2015; Aktoz et al., 2016; Cakir et al., 2016; Demirel et al., 2016], and 400 mg/kg [Oshima et al., 2015] of WR-2721, i.p.) which clearly shows that the optimum dose of this radioprotective agent is much higher than the dose used by Kumar et al. Interestingly, the authors have not even performed any experiment to determine the optimum dose of Sesamol and the rationale for using the dose of 20 mg/kg is not clear. Another shortcoming of this paper is due to overfocusing on traditional Walter Reed (WR) radioprotectors and ignoring the key role of radiation mitigators in a wide range of applications from nuclear accidents to space missions. Recent studies show the significant radioprotective effect of vitamin C and introduces this antioxidant agent as a non-toxic, cost-effective, easily available radioprotector in life-threatening exposure to lethal doses of ionizing radiation [Mortazavi et al., 2015b]. Furthermore, vitamin C can be used at intervals longer than 24 h after exposure [Mortazavi et al., 2014, 2015a]. It is worth mentioning that Kumar et al. again without knowing the optimum dose of vitamin C or melatonin have compared their radioprotective effects with that of Sesamol “Strong C 2017 Wiley Periodicals, Inc. V antioxidant activity of sesamol has been reported in comparison to standard antioxidants like vitamin C, curcumin, melatonin, etc. [Mishra et al., 2012]; additionally, in V79 cells it has shown higher radioprotection as compared to melatonin [Mishra et al., 2011]”. Another shortcoming of this paper is due to using soybean oil for preparing Sesamol while amifostine was prepared in distilled water “Sesamol was dissolved in 2% (v/ v) DMSO, and final volume was made up with soybean oil to obtain dose of 20 mg/kg bd wt (200 mL) for each animal. While same dose of amifostine was prepared in distilled water. Mice were administered (i.p.) sesamol and amifostine in their respective groups.”. In this light, it can be hypothesized that at least some of the observed radioprotective effects of Sesamol could be due to soybean oil. CONFLICT OF INTEREST None declared by the authors REFERENCES Akbulut S, Sevmis S, Karakayali H, Bayraktar N, Unlukaplan M, Oksuz E, Dagdeviren A. 2014. Amifostine enhances the antioxidant and hepatoprotective effects of UW and HTK preservation solutions. World J Gastroenterol 20:12292–12300. Aktoz T, Caloglu M, Yurut-Caloglu V, Yalcin O, Aydogdu N, Nurlu D, Arda E, Inci O. 2016. Histopathological and biochemical *Correspondence to S. M. J. Mortazavi, Ph.D, Professor of Medical Physics, Visiting Scientist at Fox Chase Cancer Center, Doss Lab R432, 333 Cottman Avenue, Philadelphia, PA 19111. E-mail: S.M.Javad. Mortazavi@fccc.edu Received 9 August 2017; provisionally accepted 11 September 2017; and in final form 00 Month 2017 DOI 10.1002/em.22143 Published online 00 Month 2017 in Wiley Online Library (wileyonlinelibrary.com). Environmental and Molecular Mutagenesis. DOI 10.1002/em 2 Mortazavi comparisons of the protective effects of amifostine and lcarnitine against radiation-induced acute testicular toxicity in rats. Andrologia. Cakir ZU, Demirel C, Kilciksiz SC, Gurgul S, Zincircioglu SB, Erdal N. 2016. Melatonin can ameliorate radiation-induced oxidative stress and inflammation-related deterioration of bone quality in rat femur. Inflammation 39:1134–1140. Demirel C, Kilciksiz SC, Gurgul S, Erdal N, Yigit S, Tamer L, Ayaz L. 2016. 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