Effects of melatonin on both testicular regeneration and recovery of spermatogenesis in busulfan-treated rats

Abstract Testicular damage is one of the most hazardous effects of chemotherapy as it is frequently associated with oligozoospermia and azoospermia. This study aimed at evaluating the protective effect of melatonin in a rat model of busulfan-induced testicular injury. Rats were divided into four groups: control, melatonin, busulfan, busulfan plus melatonin. After 15 days, the semen was collected from the epididymis and testes were assessed. Sperm removed from cauda epididymis and analyzed for sperm count and viability. Testis tissues were also removed, fixed in formalin and were embedded in paraffin. Sections of testis tissue were stained with hematoxylin-eosin for histological examination and prepared for TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labeling) assay to detect apoptosis and PCNA (proliferating cell nuclear antigenassay) to detect proliferation cells. Serum and testes supernatants were separated to detect testosteron level and oxidative stress parameters. In histological examination, degenerative changes in seminiferous tubules were observed in the experimental groups. In biochemical examination, the total oxidant status (TOS) levels in Busulfan group were significantly higher than in the control group while the total antioxidant status (TAS) levels of all the groups were similar. In conclusion, the beneficial properties of melatonin treatment by its potent anti-oxidants may reduce adverse effects of chemotherapy in the reproductive system in a rodent system.

Effects of melatonin on acetylsalicylic acid induced gastroduodenal and jejunal mucosal injury.

We evaluated the effects of melatonin on acetylsalicylic acid (ASA) induced gastroduodenal and jejunal mucosal injury. We used 40 postpubertal rats divided randomly into five groups of eight animals. The control group consisted of untreated animals. The Mel group was injected intraperitoneally (i.p.) with 5 mg/kg melatonin. The ASA group was injected i.p. with 200 mg/kg ASA. The ASA + Mel group was injected i.p. with 5 mg/kg melatonin 45 min after administering 200 mg/kg ASA i.p. The Mel + ASA group was injected i.p. with 5 mg/kg melatonin 45 min before administering 200 mg/kg ASA i.p. We found no statistically significant differences in mean histopathological scores in the ASA + Mel group compared to the ASA group. ASA caused shortened villi and loss of the apical villus in the duodenum. The histopathological score was increased and villus height was decreased in the ASA group compared to untreated controls. Treatment with melatonin attenuated the histological damage. In the ASA group, occasional areas showed erosion of villi in the jejunum; however, differences in mean histopathological score in ASA group compared to the other groups were not statistically significant. Malondialdehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD) activities were measured in stomach, duodenal and jejunum tissue. We found increased MDA activity in both stomach and duodenal tissues in the ASA group compared to the control group (p < 0.05). We found no statistically significant changes in MDA levels in jejunal tissue in the ASA group compared to the control group. We found no change in SOD activity in either stomach or duodenal tissues in the ASA group compared to the control group. We observed decreased SOD activity in jejunal tissue in the ASA group compared to the control group (p < 0.05). We detected no change in GSH activity in stomach, duodenal or jejunal tissues in the ASA group compared to the control group. The stomach damage was less in melatonin treated groups, but the lesions were not completely eliminated. The jejunum in the ASA group retained a nearly normal appearance. We found that melatonin exhibited some healing effects on ASA induced duodenal mucosal injury.

The protective effect of melatonin in lungs of newborn rats exposed to maternal nicotine.

We investigated possible healing effects of melatonin (MEL) on biochemical and histological changes in the lungs of rat offspring caused by exposure to nicotine (NT) in utero. Pregnant rats were divided randomly into five groups. The SP group was treated with physiological saline. The EA group was treated with ethyl alcohol. The MEL group was treated with MEL. The NT group was treated with NT. The NT + MEL group was treated with NT and MEL. At the end of the study, the biochemistry and histopathology of lung tissue of the offspring were examined. Reduced alveolar development and increased numbers of alveolar macrophages and mast cells were observed in the NT group compared to the SP, EA and MEL groups. We also found increased malondialdehyde (MDA) levels and decreased total glutathione (GSH) levels in the NT group. Application of MEL ameliorated the histological and biochemical damage caused by NT. The number of alveoli was greater in the NT + MEL group than in the NT group. Also, the increased numbers of alveolar macrophages and mast cells resulting from exposure to NT were decreased following MEL treatment. We found that MEL caused a significant decrease in the level of MDA. Maternal exposure to NT caused significant structural and biochemical changes in the lungs of the offspring and administration of MEL ameliorated the changes.

Effects of ciprofloxacin on fetal rat liver during pregnancy and protective effects of quercetin.

Urinary tract infections are common in pregnant women and ciprofloxacin frequently is used as a broad spectrum antibiotic. It has been suggested that ciprofloxacin causes liver damage in fetuses. Quercetin is a flavonoid with antioxidant properties. We investigated the efficacy of quercetin treatment for preventing fetal liver damage caused by ciprofloxacin. Pregnant rats were divided into four groups: untreated control group (C), 20 mg/kg quercetin for 21 days group (Q), 20 mg/kg twice/day ciprofloxacin for 10 days group (CP), and 20 mg/kg, ciprofloxacin + quercetin for 21 days group (CP + Q). Fetal livers were removed on day 21 of gestation to measure antioxidants and for histological observation. Malondialdehyde (MDA) and glutathione (GSH) levels, and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities were measured in tissue samples. GSH-Px, SOD and CAT activities were significantly lower in the CP group compared to group C. A significant increase in MDA was observed in the CP group compared to group C. There was no significant difference in GSH levels in any group. MDA levels were lower and CAT, SOD and GSH-Px enzyme activities were higher in the CP + Q group compared to group CP. Liver samples of the CP group exhibited central vein dilation, portal vein congestion, pyknotic nuclei and cytoplasmic vacuolization in some hepatocytes. Histological changes were less prominent in the rats treated with quercetin. Use of ciprofloxacin during pregnancy caused oxidative damage in fetal liver tissue. Oxidative stress was ameliorated by quercetin. Quercetin supports the antioxidant defense mechanism and it is beneficial for treating fetal liver damage caused by ciprofloxacin.

Therapeutic effects of melatonin and quercetin in improvement of hepatic steatosis in rats through supression of oxidative damage.

BACKGROUND: Non-alcoholic steatohepatitis, a cause of cirrhosis, is characterized by fatty infiltration of the liver, inflammation, hepatocellular damage and fibrosis. The aim of the present study was to investigate the effects of melatonin and quercetin on CCl4-induced steatosis characterized by fatty infiltration of the liver, inflammation, hepatocellular damage and fibrosis. METHODS: Rats were divided into 5 groups: Ethanol, Olive oil, CCl4, CCl4+Melatonin (CCl4+Mel), CCl4+Quercetin. Rats were sacrificed and livers were removed for being evaluated by histopathological, immunohistochemical and biochemical methods. RESULTS: In CCI4 group, vacuolization, vascular congestion, haemorrhage, necrosis, and inflammatory infiltration were identified. The mean tissue MDA level was increased, whereas GSH level and SOD and CAT activities were decreased in comparison with ethanol and olive oil groups. MDA levels were decreased in CCI4+Quercetin and CCI4+Mel groups versus CCI4 group. CAT activity of CCI4+Mel group was higher than that of CCI4 and CCI4+Quercetin groups. The mean tissue GSH level of CCI4+Mel group versus CCI4 group was significantly increased. CONCLUSIONS: By the means of histopathological examination, we suggest that both agents are beneficial against necrotic and apoptotic cell death during steatosis. Thus, melatonin and quercetin might be beneficial in the improvement of hepatic steatosis by supporting conventional therapy in humans (Tab. 1, Fig. 5, Ref. 53).

Preventive effects of Resveratrol against azoxymethane-induced testis injury in rats.

To evaluate the protective effects of Resveratrol (RES) on azoxymethane (AOM)-induced testicular damage using histopathology and biochemical analyses, 28 male rats were randomly divided into four groups. Groups were control, RES, AOM and ARES. At the end of the 7 weeks, following routine tissue processing procedure, testis sections were stained with haematoxylin-eosin and Masson's trichrome. The blood samples were taken for biochemical analysis of testosterone, total oxidative stress, total antioxidant status and oxidative stress index. Degenerative changes in the seminiferous tubules such as atrophy, loss in the number of germ cells and arrested spermatogenic cell, and increase in the connective tissue of the tunica albuginea in the groups with AOM treatment were found. RES treatment (ARES) reduced the number of affected seminiferous tubules significantly (p < .05) compared to AOM alone. The testosterone levels in AOM group were significantly lower than in the control group (p < .05). The total oxidative stress levels were significantly higher in AOM group compared to control group (p < .05). The total antioxidant status levels in ARES group were significantly higher than in the AOM group (p < .05). This study results suggest that an antioxidant like Resveratrol may be useful for decreasing the harmful effects of azoxymethane.

Ascorbic acid and beta-carotene reduce stress-induced oxidative organ damage in rats.

Antioxidants are potential therapeutic agents for reducing stress-induced organ damage. We investigated the effects of ascorbic acid and ß-carotene on oxidative stress-induced cerebral, cerebellar, cardiac and hepatic damage using microscopy and biochemistry. Male Wistar albino rats were divided into five groups: untreated control, stressed, stressed + saline, stressed + ascorbic acid and stressed + ß-carotene. The rats in the stressed groups were subjected to starvation, immobilization and cold. The histopathological damage scores for the stressed and stressed + saline groups were higher than those of the control group for all organs examined. The histopathological damage scores and mean tissue malondialdehyde levels for the groups treated with antioxidants were lower than those for the stressed and stressed + saline groups. Mean tissue superoxide dismutase activities for groups that received antioxidants were higher than those for the stressed + saline group for most organs evaluated. Ascorbic acid and ß-carotene can reduce stress-induced organ damage by both inhibiting lipid oxidation and supporting the cellular antioxidant defense system.

The effects of caffeic acid phenethyl ester on streptozotocin-induced diabetic liver injury.

The aim of the present study was to clarify the role of oxidative stress in streptozotocin induced liver injury and the possible protective effect of caffeic acid phenethyl ester (CAPE) using histological and biochemical parameters. 32 male Wistar rats were divided into 4 groups as follows: Group 1: Control animals, Group 2: Control animals given CAPE Group 3: STZ-induced diabetic animals (DM group), Group 4: STZ-induced diabetic rats given CAPE (DM+CAPE group). All the injections started on the same day of single-dose STZ injection and continued for 20 days. At the end of this period, livers were removed and processed for routine histological procedures. Biochemical parameters and morphological changes were examined. In DM group, blood glucose levels were significantly increased compared with the control group. Significant increases in tissue malondialdehyde (MDA) level and decreases in superoxide dismutase (SOD) and total glutathione (GSH) activities were detected in DM group. Administration of CAPE significantly reduced these values. STZ-induced histopathological alterations including inflammatory cell infiltration around portal triad, congestion, loss of glycogen in the hepatocytes. Additionally, degenerative cellular alterations, such as numerous vacuolizations including myelinic figure formation, pyknotic nuclei with peripheral localization of heterochromatin condensation and mitochondrial elongation were observed in cytoplasm of hepatocytes. CAPE significantly reduced these histopathological changes. Our results indicate that CAPE should be considered in the prevention of oxidative stress in diabetic liver.

Quercetin protection against ciprofloxacin induced liver damage in rats.

Ciprofloxacin is a common, broad spectrum antibacterial agent; however, evidence is accumulating that ciprofloxacin may cause liver damage. Quercetin is a free radical scavenger and antioxidant. We investigated histological changes in hepatic tissue of rats caused by ciprofloxacin and the effects of quercetin on these changes using histochemical and biochemical methods. We divided 28 adult female Wistar albino rats into four equal groups: control, quercetin treated, ciprofloxacin treated, and ciprofloxacin + quercetin treated. At the end of the experiment, liver samples were processed for light microscopic examination and biochemical measurements. Sections were prepared and stained with hematoxylin and eosin, and a histopathologic damage score was calculated. The sections from the control group appeared normal. Hemorrhage, inflammatory cell infiltration and intracellular vacuolization were observed in the ciprofloxacin group. The histopathological findings were reduced in the group treated with quercetin. Significant differences were found between the control and ciprofloxacin groups, and between the ciprofloxacin and ciprofloxacin + quercetin groups. Quercetin administration reduced liver injury caused by ciprofloxacin in rats. We suggest that quercetin may be useful for preventing ciprofloxacin induced liver damage.

Beneficial effects of quercetin on renal injury and oxidative stress caused by ciprofloxacin in rats: A histological and biochemical study.

Ciprofloxacin is a broad-spectrum quinolone antibiotic commonly used in clinical practice. Quercetin is an antioxidant belongs to flavonoid group. It inhibits the production of superoxide anion. In this study, we aimed to evaluate the effects of quercetin on renal injury and oxidative stress caused by ciprofloxacin. Twenty-eight female Wistar albino rats were divided into four groups: control, quercetin (20 mg kg(-1) day(-1) gavage for 21 days), ciprofloxacin (20 mg kg(-1) twice a day intraperitoneally for 10 days), and ciprofloxacin + quercetin. Samples were processed for histological and biochemical evaluations. Malondialdehyde (MDA) and glutathione (GSH) levels, superoxide dismutase (SOD), and catalase (CAT) activities were measured in kidney tissue. The ciprofloxacin group showed histopathological changes such as infiltration, dilatation in tubules, tubular atrophy, reduction of Bowman's space, congestion, hemorrhage, and necrosis. In the ciprofloxacin + quercetin group, these histopathological changes markedly reduced. MDA levels increased in the ciprofloxacin group and decreased in the ciptofloxacin + quercetin group. SOD and CAT activities and GSH levels significantly decreased in the ciprofloxacin group. On the other hand, in the ciprofloxacin + quercetin group, SOD and CAT activities and GSH levels significantly increased with regard to the ciprofloxacin group. We concluded that quercetin has antioxidative and therapeutic effects on renal injury and oxidative stress caused by ciprofloxacin in rats.

The effects of pentoxifylline and caffeic acid phenethyl ester in the treatment of d-galactosamine-induced acute hepatitis in rats.

The aim of this study was to investigate histological changes in hepatic tissue and effects of pentoxifylline (PTX) and caffeic acid phenethyl ester (CAPE) on these changes using histochemical and biochemical methods in rats, in which hepatitis was established by D-galactosamine (D-GAL). Rats were divided into five groups as follows: control group, D-GAL (24 h) group, D-GAL group, d-GAL + PTX group, and D-GAL + CAPE group. In histological evaluations, the control group showed normal appearance of the liver cells. However in the d-GAL groups, focal areas consisting of inflammatory, necrotic, and apoptotic cells were detected in parenchyma. Glycogen loss was observed in the hepatocytes localized at the periphery of lobule. It was found that number of mast cells of portal areas were significantly higher in D-GAL groups compared with other groups (p = 0.0001). In addition, the number of cells with positive staining by Ki-67 and caspase-3 were significantly increased in GAL groups compared with the control group (p = 0.0001). In biochemical analysis, there was an increase in malondialdehyde and myeloperoxidase levels, while a decrease was observed in glutathione level and glutathione peroxidase activity in groups treated with d-GAL compared with the control group. On the other hand, it was seen that, in the groups treated with D-GAL, histological and biochemical injuries in the liver were reduced by administration of PTX and CAPE. In this study, we demonstrated the ameliorative effects of PTX and CAPE on D-GAL-induced liver injury.

Assessment of the biocompatibility of mineral trioxide aggregate, bioaggregate, and biodentine in the subcutaneous tissue of rats.

OBJECTIVE: The objective of this study was to evaluate the tissue inflammation caused by three endodontic repair materials. MATERIALS AND METHODS: The materials included micro mega-mineral trioxide aggregate (MM-MTA), bioaggregate (BA), and biodentine (BD), which were implanted into the subcutaneous tissue of rats. The tissue samples for histological examination were prepared. The infiltration of lymphocytes and macrophages into the tissue was examined to assess the inflammatory response. RESULTS: Lymphocyte infiltration: A significant increase was detected in the MM-MTA and BA groups on the 7th and 14th days as compared with the control (7th day P=0.0001, 14th day P=0.0176). There was no difference between the groups on the 45th day (P=0.1730). Lymphocyte infiltration had decreased over time in all groups. Macrophage infiltration: There was a significant increase by the 7th day in the test groups as compared to the control group (P=0.007). However, there was no difference between the experimental groups on the 14th (P=0.2708) and 45th (P=0.1291) days. CONCLUSION: While MM-MTA and BA showed a similar biocompatibility, BD was more biocompatible than MM-MTA and BA in the 1 st week of the experiment. However, there was no difference between the materials at the end of the 45th day. MM-MTA, BA, and BD can be considered suitable endodontic repair materials.

Melatonin, quercetin and resveratrol attenuates oxidative hepatocellular injury in streptozotocin-induced diabetic rats.

In this study, effects of melatonin, quercetin and resveratrol on hepatocellular injury in streptozotocin (STZ)-induced experimental diabetes were aimed to be investigated by histological and biochemical methods. Thirty-five male Wistar albino rats were divided into five groups, namely, control, diabetes (STZ 45 mg/kg/single dose/intraperitoneally (ip)), diabetes + melatonin (10 mg/kg/30 days/ip), diabetes + quercetin (25 mg/kg/30 days/ip) and diabetes + resveratrol (10 mg/kg/30 days/ip). Initial and final blood glucose levels and body weights (BWs) were measured. At the end of the experimentation, following routine tissue processing procedure, sections were stained with haematoxylin-eosin (H-E), periodic acid Schiff and Masson's trichrome. Tissue malondialdehyde (MDA) and glutathione (GSH) levels and superoxide dismutase (SOD) and catalase (CAT) activities were examined. The diabetic rats had significantly higher blood glucose levels than those of control rats (p = 0.0001). Mean BWs of diabetic rats were significantly decreased when compared with the control rats (p = 0.0013). Histopathological alterations including cellular glycogen depletion, congestion, sinusoidal dilatation, inflammation and fibrosis were detected in diabetes group. On the other hand, histopathological changes markedly reduced in all of the treatment groups (p = 0.001). Mean tissue MDA level was increased but mean tissue CAT and SOD activities and GSH levels were decreased in the diabetes group. Melatonin, quercetin and resveratrol administered diabetic rats showed an increase in CAT activities and GSH levels and a decrease in MDA levels (p < 0.05, for all). Melatonin, quercetin and resveratrol administrations markedly reduced hepatocellular injury in STZ-induced experimental diabetes.