The effects of magnesium sulfate on cyclophosphamide-induced ovarian damage: Folliculogenesis

Cyclophosphamide (CYP) is one of the alkylating chemotherapeutic agents and its adverse effects on folliculogenesis in the ovary are well-known due to the previous scientific research on this topic. Magnesium has various effects in organisms, including catalytic functions on the activation and inhibition of many enzymes, and regulatory functions on cell proliferation, cell cycle, and differentiation. In this study, the effects of magnesium sulfate (MgSO₄) on CYP induced ovarian damage were investigated. Immature Wistar-Albino female rats of 28-days were treated with pregnant mare serum gonadotrophin (PMSG) to develop the first generation of preovulatory follicles. Rats of the experimental groups were then treated with either CYP (100 mg/kg, i.p) and MgSO₄ (270 mg/kg loading dose; 27 mg/kg maintenance doseX12, i.p) solely or in combination. Following in-vivo 5-bromo-2-deoxyuridine (BrdU) labeling, animals were sacrificed and ovaries were embedded in paraffin and Epon. In the ovaries, added to the evaluation of general morphology and follicle count; BrdU and TUNEL-labeling, cleaved caspase-3 and p27 (cyclin-dependent kinase inhibitor) staining was also performed immunohistochemically and an ultrastructural evaluation was performed by transmission electron microscopy (TEM). The number of primordial follicles were decreased and multilaminar primary and atretic follicles were increased in CYP group. After MgSO₄ treatment, while primordial follicle pool were elevated, the number of atretic follicles were decreased. Additionally, decreased BrdU-labeling, increased cleaved caspase 3 immunoreactivity and increased TUNEL labeling were observed in CYP group. In CYP treated animals, observations showed that while MgSO₄ administration caused no alterations in BrdU proliferation index and caspase-3 immunoreactivity, it significantly reduced the TUNEL labeling. It was also observed that, while p27 immunoreactivity significantly increased in the nuclei of granulosa and theca cells in the CYP group; MgSO₄ treatment significantly reduced these immunoreactivities. The ultrastructural observations showed frequent apoptotic profiles in granulosa and theca cells in both early and advanced stages of follicles in the CYP group and the MgSO₄ treatment before the CYP application led to ultrastructural alleviation of the apoptotic process. In conclusion, our data suggest that MgSO₄ may provide an option of pharmacologic treatment for fertility preservation owing to the beneficial effects of on chemotherapy-induced accelerated follicular apoptotic process, and the protection of the primordial follicle pool.

Fetal neuroprotective mechanism of maternal magnesium sulfate for late gestation inflammation: in a rodent model

Background: Maternal administration of magnesium sulfate (Mg) is used in humans to protect the fetal brain during preterm delivery. We sought to determine the neuroprotective mechanism of Mg in a rat model of late gestation maternal inflammation.Methods: Pregnant rats at 20 d of gestation (20 total, four groups, N = 5 in each group) received i.p. LPS or saline. Dams were randomized for s.c. saline or Mg supplementation 2 h prior and following the LPS/saline injections. Dams were sacrificed 4 h following the last treatment. Fetal brains were collected from the four treatment groups. Fetal brain caspase 3 active form, NF-kB p65, neuronal nitric oxide synthase (phospho-nNos), and proinflammatory cytokines levels were determined by western blot.Results: Maternal LPS at e20 significantly (p < .01) increased fetal brain caspase 3 active form (af) (0.27 ± 0.02 versus 0.15 ± 0.06u), NFkB (0.23 ± 0.01 versus 0.13 ± 0.01u), and phospho-nNOS (0.22 ± 0.01 versus 0.12 ± 0.01u) and fetal brain proinflammatory cytokines (IL-6 0.21 ± 0.01 versus 0.11 ± 0.01 u; TNFα 0.29 ± 0.01 versus 0.15 ± 0.01u), compared with control fetuses. Mg treatment significantly (p < .05) reduced fetal brain caspase 3 af (0.16 ± 0.01u), NFkB p65 (0.11 ± 0.01u), phospho-nNOS (0.1 ± 0.01u), as well as brain proinflammatory cytokines (IL-6 0.07 ± 0.01u; TNFα 0.15 ± 0.01u) to levels similar to controls.Conclusion: Maternal inflammation-induced fetal brain injury at late gestation may be mediated by the activation of inflammatory response, oxidative stress, and apoptosis. Maternal Mg may attenuate the injury by inhibition of these putative pathways.

Neuroprotective effect of long-term MgSO4 administration after cerebral hypoxia-ischemia in newborn rats is related to the severity of brain damage

Previous studies have shown contradictory results regarding magnesium-mediated neuroprotection in animal models of perinatal asphyxia. The aim of this study is to investigate the effects of MgSO(4) postasphyxial treatment on hypoxia-ischemia (HI)-induced brain injury in neonatal rats and the possibility that this effect is related to the severity of brain damage. Seven-day-old rats underwent unilateral carotid artery ligation followed by 1 or 2 hours of hypoxia (8% O(2)) and MgSO(4) administration. Adenosine triphosphate/phosphocreatine and glutamate/glutamine measurements and neuropathological evaluation of the hippocampus were used to assess the effects of HI and MgSO(4). HI caused time-dependent changes in energy stores, amino acid concentrations, and brain damage. Administration of MgSO(4) after 1 hour but not after 2 hours of hypoxia resulted in significant prevention of HI-induced brain injury. MgSO(4) administration results in a significant protection against moderate HI-induced brain damage, whereas it fails to offer a similar effect against severe brain damage.