Pretreatment with melatonin improves ovarian tissue cryopreservation for transplantation

Abstract

Backgroud Melatonin has anti-inflammatory and antioxidative actions at the mitochondrial level. This indole-containing molecule may protect ovarian grafts during the process of cryopreservation. Therefore, we aimed to determine whether melatonin pretreatment improves rat ovarian graft quality. Methods Twenty-six female rats were allocated to two study groups of thirteen animals each: 1) control group: ovaries cryopreserved using the standard protocol; and 2) melatonin group: ovaries cryopreserved in a medium with melatonin. Ten rats of each group were submitted to 24-h freezing, and whole ovaries autologous and avascular transplantation with retroperitoneal placement. After postoperative (PO) day 15, daily vaginal smears were obtained for estrous cycle characterization. Between PO days 30 and 35, the animals were euthanized and ovarian grafts were recovered for histological and immunohistochemical (Ki-67, cleaved caspase-3, TUNEL, von Willebrand factor, estrogen, and progesterone receptors) analyses. The ovaries of the three remaining rats from each group were studied immediately after thawing to assess the effects of cryopreservation. ANOVA and Tukey’s tests were used and the rejection level of the null hypothesis was set at 0.05 or 5% (p < 0.05). Results Melatonin promoted faster restart of the estrous cycle and increased the expression of mature follicles, collagen type I, von Willebrand factor, Ki-67, and cleaved caspase-3 on corpora lutea and estrogen receptors in the ovaries as compared to control. There was a reduction in apoptosis by TUNEL on follicles, corpora lutea, and collagen type III. Conclusion Based on the evaluated parameters, melatonin may promote the quality of ovarian grafts. Reproductive function enhancement should be further studied.

E-cadherin and NF-κB expression in the vagina after ovarian ischemia and reperfusion

“…Shiroma et al found that melatonin promoted faster resumption of the estrous cycle compared to control and increased the expression of mature follicles, collagen type I, von Willebrand factor, Ki-67, and cleaved caspase-3 on estrogen receptors in the corpus lutea and ovaries. It has also been stated that there was a decrease in apoptosis in follicles, corpus lutea and collagen type III with TUNEL 22 .…”

Changes in cardiac cells due to ticagrelor and enoxaparin in a rat ischemia/reperfusion model

“…ROS are potent oxidizing and reducing agents, which activate neutrophil and lipid peroxidation, leading to cell membrane damage 19 . In the study by Shiroma ME et al 20 , it has been shown that melatonin can support better quality ovarian grafts in inflammatory processes and oxidative stress and explained that the purpose of cell protection is to prevent mitochondrial apoptosis by reducing bcl2 expression in I/R injuries that damage cells and mitochondria 20 While caspase-3 total index was significantly higher in Group 2 compared with Group 1 (*p<0.001), this index was significantly decreased in the pretreatment groups (Group 3 and Group 4) compared with Group 2 (**p<0.001).…”

Melatonin Protects Against Cyclophosphamide-induced Premature Ovarian Failure in Rats

“…Several studies revealed that melatonin reduces oxidative stress in ovarian follicles via its antioxidative action, thereby protecting oocytes and granulosa cells. 13,22,23 Several studies reported that melatonin protects granulosa cells and oocytes from ROS by reducing oxidative stress. 24,25 Tamura et al 12 showed that melatonin blocked the inhibitory effect of H 2 O 2 on oocyte maturation via reduction of ROS in oocytes.…”

“…12 Clinical trials have shown that melatonin improves the outcomes of infertile patients who have undergone assisted reproductive technologies including in-vitro fertilization and embryo transfer. 13 Melatonin inhibits ovarian damage caused by radiotherapy and plays an anti-radiation role mainly by scavenging free radicals. 14 When melatonin interacts with -OH, it forms a transitional indolyl, which has low toxicity and can continue to react with -OH to produce 3-hydroxyl melatonin.…”