Neurotensin receptor-1 antagonist SR48692 modulation of high-fat diet induced reproductive impairment in male mice

Neurotensin (NTS), a tridecapeptide of the gastrointestinal tract, has been implicated in the facilitation of lipid absorption on ingestion of a high-fat diet (HFD) especially via NTS receptors, NTSR1, NTSR2, and NTSR3, to cause lipid metabolic dysregulation and imbalance of the oxidant-antioxidant system. Oxidative stress induced a negative impact on reproductive function, affecting the reproductive organ and related reproductive hormones. The present study elucidated the efficacy of NTSR1 antagonist SR48692 in the modulation of HFD-induced reproductive impairment in male mice. Swiss albino mice (male, 23 ± 2 g) were maintained (6/group) for eight weeks; Group-I chow diet (CD), Group-II HFD, Group-III (HFD+SR48692L), Group-IV (HFD+SR48692H), Group-V (CD+SR48692L) and Group-VI (CD+SR48692H). SR48692 low (100 µg/kg b.w./SR48692L) and high-dose (400 µg/kg b.w./SR48692H) were given intraperitoneally for the last four weeks. Treatment with low-dose (SR48692L) to HFD-fed mice showed some efficacy in mitigating lipid dysregulation, oxidative stress, and reproductive impairment as evidenced by decreased triglycerides, total cholesterol, low-density lipoprotein cholesterol, leptin, and increased high-density lipoprotein cholesterol, increased antioxidant defense enzymes, reduction of histopathological scores in testis and increase in plasma level of LH, FSH and testosterone compared to that of HFD, but not up to CD. With the high-dose of antagonist (SR48692H) showed more adverse effects even from that of HFD. Treatment of both doses of SR48692 to CD-fed mice these effects become more extended. Less effectiveness of NTSR1 antagonist with the doses tried (low and high) in normalizing the lipid dysregulation and reproductive impairments might be due to the persistence of NTSR2/NTSR3-mediated lipid absorption.

Activated Nrf-2 Pathway by Vitamin E to Attenuate Testicular Injuries of Rats with Sub-chronic Cadmium Exposure

Cadmium (Cd), a heavy metal element, cumulates in the testis and can cause male reproductive toxicity. Although vitamin E (VE) as one of potential antioxidants protects the testis against toxicity of Cd, the underlying mechanism remained uncompleted clear. The aim of this study was to investigate whether the Nrf-2 pathway is involved with the protective effect of VE on testicular damages caused by sub-chronic Cd exposure. Thirty-two SD rats were divided into four groups and orally administrated with VE and/or Cd for 28 consecutive days: control group, VE group (100 mg VE/kg), Cd group (5 mg CdCl₂/kg), and VE + Cd group (100 mg VE/kg + 5 mg CdCl₂/kg). The results showed that 28-day exposure of Cd caused accumulation of Cd, histopathological lesions, and alternations of sperm parameters (elevated rate of abnormal sperm, decreased count of sperm, declined motility, and viability of sperm). Moreover, the rats exposed to Cd showed significant oxidative stress (increased contents of MDA and decreased levels or activities of T-AOC, GSH, CAT, SOD and GSH-Px) and inhibition of Nrf-2 signaling pathway (downregulation of Nrf-2, HO-1, NQO-1, GCLC, GCLM and GST) of the testes. In contrast, VE treatment significantly reduced the Cd accumulation, alleviated histopathological lesions and dysfunctions, activated Nrf-2 pathway, and attenuated the oxidative stress caused by Cd in the testes of rats. In conclusion, VE, through upregulating Nrf-2 pathway, could protect testis against oxidative damages induced by sub-chronic Cd exposure.

Effect of crocin on biochemical parameters, oxidative/antioxidative profiles, sperm characteristics and testicular histopathology in streptozotocin-induced diabetic rats

OBJECTIVE

Chronic hyperglycemia and overproduction of reactive oxygen species (ROS) are strong predictors of the development of reproductive complications of diabetes. The present study was conducted to determine the effects of crocin on biochemical parameters, oxidative stress, and sperm characteristics as well as testes histopathology in diabetic rats.

MATERIALS AND METHODS

Twenty-four rats were divided into the four groups as follows: control, untreated diabetic and two crocin (40 and 60 mg/kg/day)-treated diabetic groups. Diabetes was induced by injection of a single dose of streptozotocin (STZ, 60 mg/kg). Administration of crocin (intraperitoneally) was started three days after STZ injection and was continued until the 28^th day. At the end of the experiment, rats were anesthetized after weighing. Blood samples and epididymal sperm were subsequently collected to measure biochemical parameters (glucose and lipid profile), total oxidant and antioxidant status (TOS and TAS, respectively), oxidative stress index (OSI), and sperm characteristics (count, motility, and viability); also, testes were dissected out for histopathology examination.

RESULTS

Our result indicated that blood glucose, cholesterol, triglyceride, LDL cholesterol levels, as well as TOS, and OSI decreased, but body weight, sperm counts, motility and viability, as well as TAS and HDL levels increased significantly in the crocin-treated diabetic rats (P˂0.05). In testis sections from diabetic rats treated with crocin (40 and 60 mg/kg), seminiferous tubules exhibited normal shape and restoration of testis architecture was observed.

CONCLUSION

Administration of crocin in the present study, ameliorated blood glucose, lipid abnormalities, oxidative stress, sperm characteristics and testis damage in STZ-diabetic rats.

Genotoxicity of carbon tetrachloride and the protective role of essential oil of Salvia officinalis L. in mice using chromosomal aberration, micronuclei formation, and comet assay

The present work was conducted to evaluate the genotoxic effect of carbon tetrachloride (CCl₄) in mouse bone marrow and male germ cells. The safety and the modulating activity of sage (Salvia officinalis L.) essential oil (SEO) against the possible genotoxic effect of CCl₄ were also evaluated. A combination of in vivo mutagenic endpoints was included: micronucleus (MN), apoptosis using dual acridine orange/ethidium bromide (AO/EB) staining, comet assay, chromosomal aberrations (CAs), and sperm abnormalities. Histological examination of testis tissues was also studied. The extracted SEO was subjected to gas chromatography-mass spectrometry (GC-MS) for identifying its chemical constituents. Safety/genotoxicity of SEO was determined after two consecutive weeks (5 days/week) from oral treatment with different concentrations (0.1, 0.2, and 0.4 mL/kg). For assessing genotoxicity of CCl₄, both acute (once) and subacute i.p. treatment for 2 weeks (3 days/week) with the concentrations 1.2 mL/kg (for acute) and 0.8 mL/kg (for subacute) were performed. For evaluating the protective role of SEO, simultaneous treatment with SEO plus CCl₄ was examined. In sperm abnormalities, mice were treated with the subject materials for five successive days and the samples were collected after 35 days from the beginning of treatment. Based on GC-MS findings, 22 components were identified in the chromatogram of SEO. The results demonstrated that the three concentrations of SEO were safe and non-genotoxic in all the tested endpoints. Negative results were also observed in bone marrow after acute and subacute treatment with CCl_4. In contrast, CCl₄ induced testicular DNA damage as evidenced by a significant increase of CAs in primary spermatocytes, sperm abnormalities, and histological distortion of testis. A remarkable reduction in these cells was observed in groups treated with SEO plus CCl₄ especially with the two higher concentrations of SEO. In conclusion, SEO is safe and non-genotoxic under the tested conditions and can modulate genetic damage and histological alteration induced by CCl₄ in the testes.

Effects of sublethal Abamectin exposure on some hormonal profiles and testicular histopathology in male albino rats and the possible ameliorative role of Eruca sativa

The ameliorative role of Eruca sativa on some hormonal profile and testicular histopathology in male albino rats exposed to a sublethal dose of 1 mg/kg body weight (b.wt). Abamectin (Crater 3.37% EC) was evaluated. Eighteen male albino rats were divided into three groups: control group, Abamectin-treated group, and Abamectin + E. sativa-treated group. Rats of the second group were orally administrated 1 mg/kg b.wt. of Abamectin, the third group received a mixture of sublethal oral dose of Abamectin (1 mg/kg b.wt.) and E. sativa suspension (5 g/kg b.wt.) every 48 h for 28 days. At the end of the study, blood samples were collected from all groups to measure some hormonal parameters; also, rats were dissected and tissue sections from the testes were prepared and stained with hematoxylin and eosin for examination under light microscope. The results of the present study revealed a disturbance in the hormonal parameters and some testicular histopathological changes. In addition, administration of E. sativa might have a promising effect against Abamectin toxicity-induced disorders of thyroid hormones and impaired testicular functions, which were correlated with histopathological changes in the testes of male rats.

Protection of testis through antioxidant action of Mallotus roxburghianus in alloxan-induced diabetic rat model

ETHNOPHARMACOLOGICAL RELEVANCE

Mallotus roxburghianus is used for its antihyperglycaemic properties in Southeast Asia especially in Northeast India (Mizoram) and is also recognized in traditional medicine. About 90% of diabetic patients have been associated with reproductive impairments. The primary aim of this investigation is to examine the effects of diabetes on oxidative stress, steroidogenesis, histopathology, proliferation of germ cells with proliferative cell nuclear antigen (PCNA) and antioxidant status, and alleviative effect of M. roxburghianus on the testis dysfunction.

MATERIALS AND METHODS

Methanolic leaf extract of M. roxburghianus was given to male albino Wistar rats by oral gavage to study the acute toxicity. Phyto-chemical composition of the methanol extract of M. roxburghianus was analyzed by GC-MS. Male Wistar rats were divided into six groups with seven animals in each group: untreated control; M. roxburghianus methanolic extract control (MRME, 400mg/kg); Alloxan diabetic control group (150 mg/kg); diabetic with 100mg/kg MRME treatment; diabetic with 400mg/kg MRME treatment; and diabetic with glibenclamide (0.1mg/kg) treatment. Diabetes was induced by a single intraperitoneal injection of 150 mg/kg alloxan and was confirmed by testing fasting plasma blood glucose levels 5 days after injection. MRME was administered orally for 28 days. Body and testis weights, serum testosterone, testis malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), glutathione S transferase (GST) and protein levels were measured, and testis tissue was examined histopathologically and immunohistochemically (PCNA).

RESULTS

No sign of mortality and organ toxicity was observed up to 3000 mg/kg in acute toxicity assay of MRME and inferred to be non-toxic and safe. Bergenin and betulinic acid are the major components of MRME with many biological activities. MRME treatment rendered significant increases in body weight, testis weight, testes-body weight ratio, down regulated the MDA levels, reduced the degeneration and disruption of seminiferous tubule structure, restored the antioxidant enzymes and serum testosterone levels, increased the PCNA activities and attenuated the testes injury.

CONCLUSION

MRME treatment to diabetic rats improves diabetes induced oxidative damage in testis as well as provides protection to testis. Phenols (Bergenin) and terpenes (Betulinic acid) were the main compounds of MRME that show antioxidant and antidiabetic activities and indeed validated its traditional use in the management of diabetes related testicular impairment.