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Radioprotective potential of melatonin against ⁶⁰Co γ-ray-induced testicular injury in male C57BL/6 mice.

Khan S, Adhikari JS, Rizvi MA, Chaudhury NK - J. Biomed. Sci. (2015)

Bottom Line: In addition, radiation-induced sperm abnormalities, motility and viability in cauda-epididymes were significantly reduced by melatonin.The detailed study will benefit in understanding the role of melatonin in modulation of radiation-induced ATM-dependent p53-mediated pro-vs.-anti apoptotic proteins in testicular injury.These results can be further exploited for use of melatonin for protection of male reproductive system in radiotherapy applications involving hemibody abdominal exposures.

View Article: PubMed Central - PubMed

Affiliation: Chemical Radioprotector and Radiation Dosimetry Research Group, Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences, Defence Research & Development Organization, Brig. S. K. Mazumdar Road, New Delhi, Delhi, 110054, India. shahanshah88@hotmail.com.

ABSTRACT

Background: Melatonin, the chief secretary product of pineal gland, is a strong free radical scavenger and antioxidant molecule. The radioprotective efficacy and underlying mechanisms refer to its antioxidant role in somatic cells. The purpose of this study, therefore, was to investigate the prophylactic implications of melatonin against γ-ray-induced injury in germinal cells (testes). C57BL/6 male mice were administered melatonin (100 mg/kg) intra-peritoneally 30 min prior to a single dose of whole-body γ-irradiation (5 Gy, 1 Gy/minute) using (60)Co teletherapy unit. Animals were sacrificed at 2h, 4h and 8h post-irradiation and their testes along with its spermatozoa taken out and used for total antioxidant capacity (TAC), lipid peroxidation, comet assay, western blotting and sperm motility and viability. In another set of experiment, animals were similarly treated were sacrificed on 1(st), 3(rd), 7(th), 15(th) and 30(th) day post-irradiation and evaluated for sperm abnormalities and histopathological analysis.

Results: Whole-body γ-radiation exposure (5 Gy) drastically depleted the populations of spermatogenic cells in seminiferous tubules on day three, which were significantly protected by melatonin. In addition, radiation-induced sperm abnormalities, motility and viability in cauda-epididymes were significantly reduced by melatonin. Melatonin pre-treatment significantly inhibited radiation-induced DNA strands breaks and lipid peroxidation. At this time, radiation-induces activation of ATM-dependent p53 apoptotic proteins-ATM, p53, p21, Bax, cytochrome C, active caspase-3 and caspases-9 expression, which were significantly reversed in melatonin pre-treated mice. This reduced apoptotic proteins by melatonin pre-treatment was associated with the increase of anti-apoptotic-Bcl-x and DNA repair-PCNA proteins in irradiated mice. Further, radiation-induced decline in the TAC was significantly reversed in melatonin pre-treated mice.

Conclusions: The present results indicated that melatonin as prophylactic agent protected male reproductive system against radiation-induced injury in mice. The detailed study will benefit in understanding the role of melatonin in modulation of radiation-induced ATM-dependent p53-mediated pro-vs.-anti apoptotic proteins in testicular injury. These results can be further exploited for use of melatonin for protection of male reproductive system in radiotherapy applications involving hemibody abdominal exposures.

No MeSH data available.


Related in: MedlinePlus

Effect of melatonin pre-treatment on DNA strands breaks of testes in mice exposed to whole-body 60Co γ-irradiation. An alkaline comet assay was performed to analyzed DNA strands breaks after 2h, 4h and 8h post-irradiation. DNA strands breaks are represented as tail length, tail moment, olive moment and % DNA in tail. *p < 0.01, **p < 0.001, ***p < 0.05, ns = non-significant (p > 0.05)
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Fig8: Effect of melatonin pre-treatment on DNA strands breaks of testes in mice exposed to whole-body 60Co γ-irradiation. An alkaline comet assay was performed to analyzed DNA strands breaks after 2h, 4h and 8h post-irradiation. DNA strands breaks are represented as tail length, tail moment, olive moment and % DNA in tail. *p < 0.01, **p < 0.001, ***p < 0.05, ns = non-significant (p > 0.05)

Mentions: Maintenance of integrity of DNA in the germ cells is of utmost importance for reproduction, and therefore protection from free radical mediated DNA damages induced by γ-radiation is necessary. In the present study, we have assessed γ-irradiation induced DNA damages in germ cells by alkaline comet assay (Fig. 8). Whole-body γ-irradiation of 5 Gy increased DNA strands breaks parameters (tail length, tail moment, olive moment and % DNA in tail) significantly at 2h (p < 0.01), 4h (p < 0.01), and 8h (p < 0.001) post-irradiation in comparison to the control (Fig. 8). Melatonin pre-treatment reduced radiation-induced oxidative DNA strands breaks significantly at 2h (p < 0.05), 4h (p < 0.05), and 8h (p < 0.01) in comparison to radiation alone treated mice. The results suggest that melatonin pre-treatment provided significant protection to DNA against oxidative damages induced by γ-irradiation in normal testicular cell (spermatogenic cells) (Fig. 8).Fig. 8


Radioprotective potential of melatonin against ⁶⁰Co γ-ray-induced testicular injury in male C57BL/6 mice.

Khan S, Adhikari JS, Rizvi MA, Chaudhury NK - J. Biomed. Sci. (2015)

Effect of melatonin pre-treatment on DNA strands breaks of testes in mice exposed to whole-body 60Co γ-irradiation. An alkaline comet assay was performed to analyzed DNA strands breaks after 2h, 4h and 8h post-irradiation. DNA strands breaks are represented as tail length, tail moment, olive moment and % DNA in tail. *p < 0.01, **p < 0.001, ***p < 0.05, ns = non-significant (p > 0.05)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4514449&req=5

Fig8: Effect of melatonin pre-treatment on DNA strands breaks of testes in mice exposed to whole-body 60Co γ-irradiation. An alkaline comet assay was performed to analyzed DNA strands breaks after 2h, 4h and 8h post-irradiation. DNA strands breaks are represented as tail length, tail moment, olive moment and % DNA in tail. *p < 0.01, **p < 0.001, ***p < 0.05, ns = non-significant (p > 0.05)
Mentions: Maintenance of integrity of DNA in the germ cells is of utmost importance for reproduction, and therefore protection from free radical mediated DNA damages induced by γ-radiation is necessary. In the present study, we have assessed γ-irradiation induced DNA damages in germ cells by alkaline comet assay (Fig. 8). Whole-body γ-irradiation of 5 Gy increased DNA strands breaks parameters (tail length, tail moment, olive moment and % DNA in tail) significantly at 2h (p < 0.01), 4h (p < 0.01), and 8h (p < 0.001) post-irradiation in comparison to the control (Fig. 8). Melatonin pre-treatment reduced radiation-induced oxidative DNA strands breaks significantly at 2h (p < 0.05), 4h (p < 0.05), and 8h (p < 0.01) in comparison to radiation alone treated mice. The results suggest that melatonin pre-treatment provided significant protection to DNA against oxidative damages induced by γ-irradiation in normal testicular cell (spermatogenic cells) (Fig. 8).Fig. 8

Bottom Line: In addition, radiation-induced sperm abnormalities, motility and viability in cauda-epididymes were significantly reduced by melatonin.The detailed study will benefit in understanding the role of melatonin in modulation of radiation-induced ATM-dependent p53-mediated pro-vs.-anti apoptotic proteins in testicular injury.These results can be further exploited for use of melatonin for protection of male reproductive system in radiotherapy applications involving hemibody abdominal exposures.

View Article: PubMed Central - PubMed

Affiliation: Chemical Radioprotector and Radiation Dosimetry Research Group, Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences, Defence Research & Development Organization, Brig. S. K. Mazumdar Road, New Delhi, Delhi, 110054, India. shahanshah88@hotmail.com.

ABSTRACT

Background: Melatonin, the chief secretary product of pineal gland, is a strong free radical scavenger and antioxidant molecule. The radioprotective efficacy and underlying mechanisms refer to its antioxidant role in somatic cells. The purpose of this study, therefore, was to investigate the prophylactic implications of melatonin against γ-ray-induced injury in germinal cells (testes). C57BL/6 male mice were administered melatonin (100 mg/kg) intra-peritoneally 30 min prior to a single dose of whole-body γ-irradiation (5 Gy, 1 Gy/minute) using (60)Co teletherapy unit. Animals were sacrificed at 2h, 4h and 8h post-irradiation and their testes along with its spermatozoa taken out and used for total antioxidant capacity (TAC), lipid peroxidation, comet assay, western blotting and sperm motility and viability. In another set of experiment, animals were similarly treated were sacrificed on 1(st), 3(rd), 7(th), 15(th) and 30(th) day post-irradiation and evaluated for sperm abnormalities and histopathological analysis.

Results: Whole-body γ-radiation exposure (5 Gy) drastically depleted the populations of spermatogenic cells in seminiferous tubules on day three, which were significantly protected by melatonin. In addition, radiation-induced sperm abnormalities, motility and viability in cauda-epididymes were significantly reduced by melatonin. Melatonin pre-treatment significantly inhibited radiation-induced DNA strands breaks and lipid peroxidation. At this time, radiation-induces activation of ATM-dependent p53 apoptotic proteins-ATM, p53, p21, Bax, cytochrome C, active caspase-3 and caspases-9 expression, which were significantly reversed in melatonin pre-treated mice. This reduced apoptotic proteins by melatonin pre-treatment was associated with the increase of anti-apoptotic-Bcl-x and DNA repair-PCNA proteins in irradiated mice. Further, radiation-induced decline in the TAC was significantly reversed in melatonin pre-treated mice.

Conclusions: The present results indicated that melatonin as prophylactic agent protected male reproductive system against radiation-induced injury in mice. The detailed study will benefit in understanding the role of melatonin in modulation of radiation-induced ATM-dependent p53-mediated pro-vs.-anti apoptotic proteins in testicular injury. These results can be further exploited for use of melatonin for protection of male reproductive system in radiotherapy applications involving hemibody abdominal exposures.

No MeSH data available.


Related in: MedlinePlus