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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 PCNA protein expression of testes in mice exposed to whole-body 60Co γ-irradiation. Western blot was performed to measured PCNA protein expression after 2h, 4h and 8h post-irradiation. The β-actin protein was used as loading control. *p < 0.001
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Fig10: Effect of melatonin pre-treatment on PCNA protein expression of testes in mice exposed to whole-body 60Co γ-irradiation. Western blot was performed to measured PCNA protein expression after 2h, 4h and 8h post-irradiation. The β-actin protein was used as loading control. *p < 0.001

Mentions: The progression of spermatogenic cell is of paramount importance for spermatogenic process, therefore, we have further evaluated the expression pattern of a nuclear protein and a co-factor for DNA polymerase δ, PCNA protein, which is reported to be involved in the RAD6-dependent DNA repair pathway in response to oxidative DNA damage. A significant decrease in PCNA protein was observed at 2h (p < 0.001), 4h (p < 0.001) and 8h (p < 0.01) in comparison to control, suggesting that the expression pattern of PCNA decreases during the course of time till it reaches the maximum level at 4h post-irradiation afterward increases (Fig. 10). Melatonin pre-treated mice displayed highly significant (P < 0.001) PCNA expression pattern in testes (Fig. 10). This indicated that melatonin pre-treatment increased PCNA protein expression, which was important for both the DNA repair and spermatogenic cell proliferation.Fig. 10


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 PCNA protein expression of testes in mice exposed to whole-body 60Co γ-irradiation. Western blot was performed to measured PCNA protein expression after 2h, 4h and 8h post-irradiation. The β-actin protein was used as loading control. *p < 0.001
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig10: Effect of melatonin pre-treatment on PCNA protein expression of testes in mice exposed to whole-body 60Co γ-irradiation. Western blot was performed to measured PCNA protein expression after 2h, 4h and 8h post-irradiation. The β-actin protein was used as loading control. *p < 0.001
Mentions: The progression of spermatogenic cell is of paramount importance for spermatogenic process, therefore, we have further evaluated the expression pattern of a nuclear protein and a co-factor for DNA polymerase δ, PCNA protein, which is reported to be involved in the RAD6-dependent DNA repair pathway in response to oxidative DNA damage. A significant decrease in PCNA protein was observed at 2h (p < 0.001), 4h (p < 0.001) and 8h (p < 0.01) in comparison to control, suggesting that the expression pattern of PCNA decreases during the course of time till it reaches the maximum level at 4h post-irradiation afterward increases (Fig. 10). Melatonin pre-treated mice displayed highly significant (P < 0.001) PCNA expression pattern in testes (Fig. 10). This indicated that melatonin pre-treatment increased PCNA protein expression, which was important for both the DNA repair and spermatogenic cell proliferation.Fig. 10

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