• Journal of Photoscience
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• 제9권2호
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• pp.472-474
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• 2002

Till date the phenomenon of maternal transfer of photic information was reported to regulate the fetal/neonatal growth, however its influence on neonatal immune system is still an enigma. In the present study, we observed an increase in maternal plasma melatonin level under short day length (SOL) condition with a consequent decrease in TLC and LC in their respective neonates. However, a significant decrease in maternal plasma melatonin level was noted under constant darkness (DD) with an increase in TLC and LC of their neonates. The blastogenic response (BGR) to Con A of splenocytes exhibited a significant increase in neonates of SDL females and a significant decrease in the neonates of DD females. Hence, it appears that the increase in maternal plasma melatonin under SOL condition transmitted information to decrease the immune status. Continuous exposure of females to darkness (DD) negatively regulated the maternal pineal gland activity thereby decreasing their plasma melatonin level. This information was transmitted for elevation of immune status in neonates, so that they exhibit better growth and sexual maturation. Therefore, we may suggest that the maternal photic information transmitted either prenatally through placenta or postnatally via the milk regulate the hormonal profile of Melatonin to regulate the immune status of neonates in order to influence their growth and sexual maturation.

• Journal of Pharmaceutical Investigation
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• 제32권2호
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• pp.107-112
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• 2002

To investigate the feasibility of developing a novel melatonin plaster, the effects of vehicles and drug loading dose on the in vitro permeation of melatonin across dorsal hairless mouse skin from pressure-sensitive adhesive (PSA) matrices were examined. Vehicles employed were propylene glycol laurate (PGL), propylene glycol monocaprylate (PGMC) and diethylene glycol monoethyl ether (DGME). Among PSAs used, only $Duro-Tak^{\circledR}$ 87-2196 showed a good peeling property. The release from $Duro-Tak^{circledR}$ 87-2196 was proportional to the square root of time, and dose-dependent. The fluxes increased as the loading dose increased over the doses under solubility. The relatively high permeation flux $(3.03{\pm}1.37\;{\mu}g/cm^2/hr)$ was obtained when using PGMC at the melatonin loading dose of $45\;mg/140\;cm^2$. Lag time was not affected by the vehicles used but by the thickness spread. The melatonin plasters prepared using PGMC showed a good adhesive property onto skin, and showed no crystal formation.

• Clinical and Experimental Reproductive Medicine
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• 제49권2호
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• pp.87-92
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• 2022

Objective: The aim of this study was to determine the effects of melatonin and selenium in freezing extenders on frozen-thawed rat sperm. Methods: Semen samples were collected from 20 adult male Wistar albino rats. Following dilution, the samples were divided into six groups: four cryopreserved groups with 1 mM and 0.5 mM melatonin and selenium supplements, and two fresh and cryopreserved control groups. The rapid freezing technique was used to freeze the samples. Flow cytometry was used to assess plasma membrane integrity, mitochondrial membrane potential, and DNA damage, while computer-assisted sperm analysis was used to assess motility. Results: Total motility was higher in the 1 mM melatonin supplementation group than in the cryopreserved control group (mean±standard error of the mean, 69.89±3.05 vs. 59.21±1.31; p≤0.05). The group with 1 mM selenium had the highest plasma membrane integrity (42.35%±1.01%). The cryopreserved group with 0.5 mM selenium had the highest mitochondrial membrane potential, whereas the cryopreserved control group had the lowest (45.92%±4.53% and 39.45%±3.52%, respectively). Conclusion: Cryopreservation of rat semen supplemented with 1 mM melatonin increased sperm motility after freeze-thawing, while supplementation with 0.5 mM selenium increased mitochondrial activity.

• 환경생물
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• 제20권3호
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• pp.224-231
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• 2002

광주기(하루 중 빛의 길이)는 골든 햄스터의 생식을 조절하는 주된 요인이다. 광주기 정보는 멜라토닌을 통하여 생식 내분비계로 전달된다. 따라서 멜라토닌이 생식에 미치는 효과를 여러 광주기에 노출시킨 햄스터에서 조사하였다. 단주기(하루 중 12시간 이하의 조명)에 노출시킨 동물들과 저녁에 멜라토닌을 주사한 동물들의 정소 무게는 현저하게 줄어들었으나, 장주기 (하루 중 12.5시간 이상의 조명)에 유지된 동물과 오전에 멜라토닌을 투여한 동물들의 정소 무게는 줄어들지 않았다. 퇴화된 정소를 조직학적으로 조사한 결과, 세정관 직경이 감소되었고, 세정관내 세포수가 두드러지게 줄어들었다. 또한 생식 능력이 퇴화된 동물의 혈중 여포자극호르몬과 황체호르몬의 수준도 생식 능력을 보유하고 있는 동물에 비해 뚜렷하게 감소하였다. 멜라토닌 수용체가 역전사 polymerase chain reaction으로 동정되었고 조직특이성 또한 조사하였다. 동정된 멜라토닌 수용체는 309염기였으며, 시상하부와 뇌하수체를 포함하는 다양한 장기에서 발현되었다. 생식을 조절하는 핵심 물질인 gonadotropin releasing hormone (GnRH) 유전자의 발현 또한 동정되었다. 그러나 멜라토닌 처리와 광주기 처리는 GnRH유전자 발현에 영향을 미치지 않았다. 종합하면, 광주기의 효과는 멜리토닌을 경유하여 발휘되며, 멜라토닌은 GnRH유전자의 발현보다는, 생성된 GnRH의 분비에 영향을 미쳐 생식내분비계에 간접적으로 작용함을 알 수 있었다.

• Archives of Plastic Surgery
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• 제35권6호
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• pp.645-652
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• 2008

Purpose: In skin flap surgery, surgeons often encounter distal ischemia of the flap. If a powerful free radical scavenger is used, it may reduce the formation of free radical and improves the survival of flap. Thus, the present study purposed to examine whether the survival of flap can be enhanced by administering melatonin, which is known to be a powerful free radical scavenger a antioxidant molecule. Methods: We divided 40 Sprague-Dawley rats into 4 groups, 10 in each group. For the control group(n=10), we intraperitoneally injected only carrier solution once 30 minutes before the operation, and once a day for 7 days from the day of operation. Among the experimental groups, a group(n=10) was administered with dimethyl sulfoxide(DMSO), in another group(n=10), melatonin was intraperitoneally injected, and in the other(n=10) melatonin was intraperitoneally injected and applied topically(2 cc of 1% melatonin) to the operation site. Caudally based skin flaps measuring $3{\times}10cm^2$ were elevated on the mid-dorsum of the rats. and then repositioned. On the seventh postoperative day, the survival area of the flap was measured and tissues were examined under the light microscope. Results: The control group, the DMSO group, the melatonin administration group and the melatonin administration and application group showed the mean survival rates of $55.26{\pm}9.2%$, $70.29{\pm}7.47%$, $81.45{\pm}4.14%$ and $86.1{\pm}1.52%$, respectively, for $30cm^2$ of flap. Compared to the control group, the experimental groups showed a significantly high increase in survival area at significance level of 95%. Conclusion: In this study, the survival rate of flap was enhanced through the administration of melatonin after flap surgery. This suggests that melatonin not only functions as a powerful free radical scavenger and oxygen radical scavenger but also stabilizes and protects cells, and by doing so, enhances the survival of moderately injured ischemic sites in the distal end of flap.

• The Korean Journal of Physiology and Pharmacology
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• 제5권3호
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• pp.223-230
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• 2001

Melatonin, a pineal gland hormone, is believed to act as an antioxidant via the stimulation of radical detoxifying enzymes and scavenging of free radicals. In this study, effects of in vitro and in vivo treatments of melatonin on the cisplatin-induced lipid peroxidation, LDH release and plasma creatinine were determined in rabbit renal cortical cells. The level of malondialdehyde (MDA) was assayed as an index of lipid peroxidation and the level of LDH release as an indicator of cellular damage. In in vitro studies, cisplatin increased the levels of MDA and LDH release in a concentration-and time-dependent manner. Melatonin inhibited the cisplatin-induced lipid peroxidation and LDH release in a concentration-dependent manner. The minimal effective concentration of melatonin that significantly reduced the $300\;{\mu}M$ cisplatin-induced lipid peroxidation and LDH release was 1 mM. In in vivo studies, the levels of lipid peroxidation and LDH release in renal cortical cells increased significantly 24 or 48 hours after a single injection of cisplatin (6 mg/kg). When the cisplatin-injected rabbits were pretreated with 10 mg/kg of melatonin, a significant reduction in both lipid peroxidation and LDH release was observed. The plasma creatinine level increased from $0.87{\pm}0.07$ mg/dl in control to $6.33{\pm}0.54$ mg/dl in cisplatin-injected rabbits (P＜0.05). Melatonin partially prevented the increase in serum creatinine level $(1.98{\pm}0.11\;mg/dl)$ by cisplatin (P＜0.05). In the proximal tubules from cisplatin-treated group, tubular cells had microvilli of variable heights. Necrotic debris was seen in tubular lumens. In most of cells, the mitochondria and lysosomes were increased in frequency. The endocytic vacuoles were not prominent and distribution of the brush border was irregular and shortened. These cisplatin-induced morphological changes were moderate in the melatonin-pretreated group. These results suggest that the toxicity of cisplatin is associated with the generation of reactive oxygen free radicals and that melatonin is a powerful antioxidant, which prevents some of the adverse effects of cisplatin.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권4호
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• pp.266-274
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• 2020

Objectives: Melatonin induces human stem cells, converts pre-osteoblasts to mature osteoblasts, and reduces the duration of this transition. However, melatonin itself prevents activation of osteoclasts. Here, we evaluate the role of melatonin in prevention of bisphosphonate-related osteonecrosis of the jaw. Materials and Methods: In this experimental-interventional study, 30 rats were evaluated in 3 groups. The first and second groups received saline and zoledronic acid, respectively, for 4 weeks and the third group received 4 weeks of zoledronic acid and 3 weeks of melatonin simultaneously. First-right-maxillary-molar extraction was performed for all animals, which were sacrificed after 4 weeks of recovery. The extraction sockets were examined histologically for the presence of osteonecrosis, number of osteoclasts and fibroblasts, severity of inflammation, and vascularization. Data were analyzed by chi-square, one-way ANOVA, Tukey, Kruskal-Wallis and Fisher's exact statistical tests (α=0.05). Results: Osteonecrosis was observed in 20%, 90%, and 70% of the first, second and third groups, respectively (P=0.008). The lowest number of osteoclasts and fibroblasts was seen in the third group. Conclusion: Melatonin may effectively prevent some undesirable side effects of bisphosphonates. However, further studies are required to confirm the results of this study.

• BMB Reports
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• 제33권6호
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• pp.463-468
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• 2000

Anthrax lethal toxin, which consists of two separate protein, protective antigen (83 KDa) and lethal factor (85 KDa) is responsible for major symptoms and death from systemic infection of Bacillus anthracis. High concentrations of this toxin are cytolytic to macrophages, whereas sublytic concentrations of lethal toxin induce these cells to produce interleukin $1{\beta}$ ($IL-1{\beta}$). It is proposed that melatonin and dehydroepiandrosterone (DHEA) may play an important role in modifying immune dysfunction. In this study, we investigated whether or not melatonin and DHEA could prevent $IL-1{\beta}$ production that is induced by anthrax lethal toxin in mouse peritoneal macrophages. Treatment of melatonin or DHEA alone, as well as together, prevented the production of $IL-1{\beta}$ caused by anthrax lethal toxin. We found that melatonin at a concentration of $10^{-6}-10^{-7}$ M inhibits $IL-1{\beta}$ production induced by anthrax lethal toxin. As expect, treatment of DHEA at a concentration $10^{-6}-10^{-7}$ M also suppressed production of $IL-1{\beta}$ by lethal toxin stimulated macrophages. The results of these studies suggest that melatonin and DHEA, immunomodulators, may have an important role in reducing the increase of cytokine production in anthrax lethal toxin-treated macrophages.

• Animal Bioscience
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• 제37권6호
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• pp.1007-1020
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• 2024

Objective: We increased the nuclear maturation rate of antral follicle derived oocytes by using a pre-in vitro maturation (IVM) culture system and improved the developmental potential of these porcine pathenotes by supplementing with melatonin. Furthermore, we investigated the expression patterns of genes involved in cumulus expansion (HAS2, PTGS2, TNFAIP6, and PTX3) derived from small and medium antral follicles before and after oocyte maturation. Methods: Only the cumulus oocyte-complexes (COCs) derived from small antral follicles were induced with [Pre-SF(+)hCG] or without [Pre-SF(-)hCG] the addition of human chorionic gonadotropin (hCG) during the last 7 h of the pre-IVM period before undergoing the regular culture system. The mature oocytes were investigated on embryonic development after parthenogenetic activation (PA). Melatonin (10^-7 M) was supplemented during in vitro culture (IVC) to improve the developmental potential of these porcine pathenotes. Results: A pre-IVM culture system with hCG added during the last 7 h of the pre-IVM period [Pre-SF(+)hCG] effectively supported small antral follicle-derived oocytes and increased their nuclear maturation rate. The oocytes derived from medium antral follicles exhibited the highest nuclear maturation rate in a regular culture system. Compared with oocytes cultured in a regular culture system, those cultured in the pre-IVM culture system exhibited considerable overexpression of HAS2, PTGS2, and TNFAIP6. Porcine embryos treated with melatonin during IVC exhibited markedly improved quality and developmental competence after PA. Notably, melatonin supplementation during the IVM period can reduce and increase the levels of intracellular reactive oxygen species (ROS) and glutathione (GSH), respectively. Conclusion: Our findings indicate that the Pre-SF(+)hCG culture system increases the nuclear maturation rate of small antral follicle-derived oocytes and the expression of genes involved in cumulus expansion. Melatonin supplementation during IVC may improve the quality and increase the blastocyst formation rate of porcine embryos. In addition, it can reduce and increase the levels of ROS and GSH, respectively, in mature oocytes, thus affecting subsequent embryos.

• Asian-Australasian Journal of Animal Sciences
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• 제20권10호
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• pp.1496-1502
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• 2007

The roles of melatonin in the control of deiodinase (MD) activity in cashmere goat skin and associated cashmere fibre growth were investigated. Eighteen half-sib Chinese Inner Mongolia cashmere wethers were allocated randomly to two groups (n = 9/group). One group was implanted subcutaneously with melatonin (2 mg/kg BW) at three 2-monthly intervals while the other group served as a control. All goats were maintained under natural photoperiodic conditions and were grazed on natural pasture. The plasma melatonin concentration showed a significant difference (p<0.01) between the implant group (M) and the control group (C) but plasma $T_4$ (or $T_3$) showed no significant difference (p>0.05). The monodeiodinase type II (MDII) activity in skin tended to increase gradually from the summer solstice to November. During July and August, the activity of MDII for the M group was higher (p<0.05) than that of the C group; also during this period, there was a significant positive correlation between MDII activity of skin and cashmere fibre growth rate. The monodeiodinase type III (MDIII) activity and the ratio of MDIII and MDII tended to decrease from the summer solstice to November. The ratio of MDIII and MDII for the M group was lower (p<0.05) than that of the C group in July and August. The cashmere fibre growth rate of the M group was significantly greater than that of the C group in July (p<0.01), August (p<0.001) and September (p<0.05). The cashmere fibre diameter and guard hair and body weight were not influenced (p>0.05) by melatonin implantation. The results demonstrate that melatonin plays an important role in the regulation of skin MD activity. Simultaneously, the cashmere fibre elongation stimulated by melatonin may result from enhanced MDII activity during a period of two months after melatonin treatment.