Dietary nucleotides protect thymocyte DNA from damage induced by cyclophosphamide in mice

Abstract

The effects of dietary nucleotides on thymocyte DNA damages induced by cyclophosphamide (CP) in mice were examined. First, phase I experiment was conducted to determine the optimal timing of detecting thymocyte DNA damages induced by CP (150 mg/kg body weight) in mice. Thymocyte DNA damages was determined at 6, 12, 18, 24 h by single-cell gel electrophosphoresis assay (comet assay) after intraperitoneal injection of CP. The levels of DNA damage at 6, 12, 18, 24 h were all significantly higher than that of the control group (p < 0.01). The highest level of DNA damage appeared at 18 h and then decreased at 24 h. Therefore, 18 h was selected to determine DNA damages induced by CP in subsequent experiments. In phase II experiment, 30 male KunMing mice were divided into three treatments: negative control (NC), positive control (PC) and nucleotides group (NG). Mice in NC and PC were fed nucleotide-free diet, and mice in NG were fed nucleotide-supplemented diet (supplemented with 0.25% nucleotides, a mixture containing equal amounts of AMP, CMP, GMP and UMP). Mice in PC and NG groups were injected with CP (150 mg/kg body weight) at 21 days. DNA damage in thymocytes was evaluated at 18 h after CP treatment. The results indicate that dietary nucleotides do not affect the weights of the thymus and the spleen, or their organ indices (p > 0.05), but significantly decrease the percentage of comet cells and comet tail sizes (p < 0.01). This study demonstrates that dietary nucleotides could reduce the level of thymocyte DNA damage induced by CP in mice.

Protection of Spleen Tissue of γ-ray Irradiated Mice against Immunosuppressive and Oxidative Effects of Radiation by Adenosine 5′-Monophosphate

“…Previously, Frankič also reported that dietary nucleotides could reduce the amount of DNA damage induced by T-2 toxin in immune cells [ 3 ]. In addition, the dietary nucleotides could reduce cyclophosphamide-induced DNA damage in immune organs in mice [ 21 ]. Our results were consistent with these reports, since nucleotides exerted protective effects on DNA.…”

Effects of dietary nucleotide supplementation on growth performance and hormonal and immune responses of piglets

“…They have important effects on the growth and development of rapid turnover cells, such as those in the -E-mail: paola.superchi@unipr.it immune system and in the gastrointestinal tract (Wang et al, 2008). In healthy conditions dietary nucleotides are probably not essential, however, during stressful or limited nutrient intake periods, dietary nucleotides may become essential (Dancey et al, 2006).…”

Preventive effect of salmon sperm DNA on acute carbon tetrachloride‐induced liver injury in mice through Nrf2/ARE and mitochondrial apoptosis pathway

“…As an important molecule for biological composition (Sánchez‐Pozo & Gil, 2002 ), nucleic acids have been reported to have a variety of beneficial physiological functions, such as antioxidation (Wang et al, 2008 ), improving immunity (Cheng et al, 2018 ; Xu et al, 2013 ), liver function (Kojima‐Yuasa et al, 2016 ; Sauer et al, 2012 ), and growth performance and nutrient utilization (Waititu et al, 2015 ), repairing intestinal injury (Meng et al, 2017 ) and regulating intestinal flora (Sauer et al, 2012 ). However, the use of natural macromolecular nucleic acids in medicine and food processing is limited because of their insolubility in water and low bioavailability.…”