Long-term intake of aspartame-induced cardiovascular toxicity is reflected in altered histochemical parameters, evokes oxidative stress, and trigger P53-dependent apoptosis in a mouse model.

Aspartame (ASP) is probably the best known artificial sugar substitute that is used widely in food. Many experimental studies have reported the toxicity of long-term administration of ASP in various organ tissues. However, there is little evidence available about the nature and mechanisms of the adverse effects of long-term consumption of ASP on the cardiovascular system. This study was conducted to evaluate the possible effects of ASP on heart tissue. For this study 36 mature male mice were divided into one control group and three groups which received respectively 40 mg/kg, 80 mg/kg and 160 mg/kg ASP orally, for 90 days. ASP at the doses of 80 and 160 mg/kg increased the serum content of malondialdehyde (MDA), but decreased serum nitric oxide (NO), creatine kinase (CK) and CK-MB, as well as blood superoxide dismutase (SOD) levels. Serum level of total anti-oxidant capacity (TAC) in blood was also reduced in serum at the dose of 80 mg/kg. Histochemical staining, including Periodic acid-Schiff, Masson's trichrome and Verhoeff-van Gieson staining, indicated that ASP at doses of 80 and 160 mg/kg reduced glycogen deposition and decreased the number of collagen and elastic fibres in the cardiac tissue. The cardiac expression of pro-apoptotic genes, including P53, Bax, Bcl-2 and Caspase-3, was modulated at the dose of 160 mg/kg. Moreover, transcription of Caspase-3 was up-regulated at the dose of 80 mg/kg. In conclusion, long-term consumption of ASP any higher than the acceptable daily intake (40 mg/kg) appears to act by promoting oxidative stress, has the potential to alter both histopathological and biochemical parameters, and induces P53-dependent apoptosis in cardiac tissue.

Insight into the mechanism of aspartame-induced toxicity in male reproductive system following long-term consumption in mice model.

Aspartame is one of the most common consumed artificial sweeteners utilized in many food products and beverages. It has been indicated that long-term consumption of aspartame leads to reproductive toxicity but its mechanism is not well-clear. In this study we investigated mechanism of aspartame-induced reproductive toxicity in male mice. For this purpose, 36 NMRI mature male mice received three doses of 40, 80, and 160 mg/kg body weight of aspartame, respectively per day by gavage for 90 days and also a control group was considered which received 0.5 mL of normal saline as the same route. The results revealed that long-term administration of aspartame at high doses significantly (P < .05) reduced gonadosomatic index, serum concentration of pituitary-testicular axis hormones (FSH, LH, and testosterone). It also decreased sperm parameters and total antioxidant capacity, antioxidant enzyme activities (superoxide dismutase, catalase, and glutathione peroxidase), while it caused increase in nitric oxide and malondialdehyde levels in testis tissue and sperm samples. Also, it decreased attenuated testicular histomorphometric indices (tubular differentiation index, spermiogenesis index, and repopulation index), and steroidogenic foci, while increased mRNA damages and apoptosis rate, downregulated antiapoptotic (Bcl-2) and upregulated proapoptotic (P53, BAX, and caspase-3) mediators respectively in testis. These findings indicated that consumption of aspartame for a long period results in male reproductive toxicity by decrease in serum concentration of pituitary-testis axis hormones and induction of oxidative stress and apoptosis in testis.

Long-Term Effect of Aspartame on Male Reproductive System: Evidence for Testicular Histomorphometrics, Hsp70-2 Protein Expression and Biochemical Status.

BACKGROUND: Aspartame is one of the most commonly consumed artificial sweeteners that is widely used in foodstuffs. There are many debatable reports about aspartame toxicity in different tissues; however, on the subject of its effects on the reproductive system, few literatures are available. The present study was carried out for evaluating effects of aspartame on the reproductive system in male mice. MATERIALS AND METHODS: In this experimental study, a total of 36 adult male mice were randomly divided into four groups of nine animals each. Three groups received aspartame at doses of 40, 80 and 160 mg/kg (gavage) for 90 days; also, a control group was considered. Twenty-four hours after the last treatment, animals were sacrificed. Then, body and testis weights, sperm parameters, serum testosterone concentration, total antioxidant capacity, and malondialdehyde (MDA) levels, antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px)] activities in blood, histomorphometrical indices and histochemical changes in testis were evaluated; also, mRNA and immunohistochemical expression of Hsp70-2 was measured in testis tissue. RESULTS: The results revealed remarkable differences in sperm parameters, testosterone and oxidative stress biomarkers levels, and histomorphometrical indices, between the control and treatment groups. Also, in 80 and 160 mg/kg aspartametreated groups, expression of Hsp70-2 was decreased. Besides, in the aspartame receiving groups, some histochemical changes in testicular tissue were observed. CONCLUSION: The findings of the present study elucidated that long-term consumption of aspartame resulted in reproductive damages in male mice through induction of oxidative stress.

Histological and histometrical evidences for phenol immunotoxicity in mice.

Phenol is a common industrial and ubiquitous environmental chemical which is used to synthesize resins and plastics. Due to its anesthetic and disinfectant properties, phenol is also widely used in pharmaceutical products. Since there were no adequate data about phenol immunotoxicity, the purpose of the present study is to investigate its toxic effects on the histological structures of the lymphoid organs in the mice. A total of 80 mice were randomly distributed into one control group and three experimental groups. The control group received only distilled water, whereas experimental groups were orally administered phenol at the concentrations of 80, 180, and 320 mg/kg/day, respectively. After 28 consecutive days, tissue samples were taken and histological changes of the spleens, thymuses, adrenal glands, and lymph nodes were examined using optical microscopy. The results showed that in the phenol treated animals; splenic megakaryocyte counts increased, the diameter of the splenic follicles decreased, the thymocyte population in both cortex and medulla reduced, the thickness of the reticular layers of adrenal gland increased and lymphatic cells populations in the lymph node were reduced, significantly (P < 0.01). Also, remarkable histological changes were noted in the various lymphatic organs of the treated mice. Overall, present findings give some histological evidences that selected qualitative and quantitative parameters of the lymphatic organs were significantly altered by phenol administration. In conclusion, the significant decreases of the immune cell populations together with histological alterations in the immunocompetent organs of the mice exposed to phenol indicate the immunosuppressive and immunotoxic properties of this chemical material.

Evaluation of histopathologic and histomorphometric changes of testicular tissue and gonadotropin levels following consumption of methylphenidate in male mice.

BACKGROUND/AIM: One of the most common psychiatric disorders in children is attention-deficit/hyperactivity disorder, which is treated extensively by methylphenidate. This study investigates the assessment of the effects of methylphenidate on histopathologic and histomorphometric changes of the testes and serum levels of gonadotropin in mice. MATERIALS AND METHODS: In this study, 36 adult male mice were used. After determining their body weights, the animals were divided randomly into 2 experimental groups and 1 control group. The experimental groups received methylphenidate (2 and 10 mg kg(-1) day(-1)) via gavage for a period of 40 days. After evaluation of body weight, general anesthesia was used for taking blood samples from the heart in order to measure testosterone and levels of gonadotropin in serum. For the purpose of weighing the bodies and measuring the thickness of the germinal epithelium, the testes were removed and the possibility of any pathological changes was considered. RESULTS: The results showed that methylphenidate could decrease the thickness of the germinal epithelium and body weight significantly, and could increase the levels of spermatogonia and serum gonadotropins and testosterone. Histopathological changes were also seen for vascular dilatation and congestion in interstitial tissue. CONCLUSION: Our findings demonstrated that administration of methylphenidate in adulthood may have an effect on spermatogenesis due to the influence of gonadotropin hormones on testis function.

Histological and mucin histochemical study of the small intestine of the Persian squirrel (Sciurus anomalus).

This article describes the histological and mucin histochemical properties of the small intestine of the Persian squirrel (Sciurus anomalus). This species is widely distributed in the Middle East and can be found as a companion animal. The histological studies revealed that the plicae circulares were not visible in the tunica mucosa. The maximum height and width of the villi were observed in the duodenum, which then decreased toward the ileum. The muscularis mucosa was scattered, whereas the tunica submucosa was composed of dense connective tissue. The lymphatic nodules were seen in the submucosa of the distal part of the jejunum and ileum, and Brunner's glands were embedded in the initial portion of the duodenum. The tunica muscularis was significantly thicker in the ileum, and the circular muscle layer was thicker than the longitudinal muscle layer throughout the entire length of the small intestine. The mucin histochemistry, which was examined using the periodic acid-Schiff (PAS) and alcian blue (AB) (pH 1.0 and 2.5) and also PAS-AB (pH 2.5) and aldehyde fuchsin-AB (pH 2.5) techniques coupled with methylation and saponification reaction for some sections, showed that the small intestine mucous content included both carboxylated and sulfated acidic mucins with few neutral mucins. The results of this study contribute to the knowledge of the histological and histochemical characteristics of the gastrointestinal tracts of exotic mammals and provide data for comparison with other mammals.

The effect of chronic administration of methylphenidate on morphometric parameters of testes and fertility in male mice.

BACKGROUND: Due to common use of methylphenidate (MPH) for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) and the role of the reproductive system in the production of gametes, studying the effects of this medication on the morphometry of testes, serum testosterone concentration, leydig cells function, and fertility rate was the aim of this study. METHODS: Twenty seven male mice (Balb/C), eight weeks old, were randomly divided into one control and two treated groups. After weighing the mice, the treated groups received MPH (produced in Novartis company) at the doses of 2 mg/kg and 10 mg/kg for 40 days. The control group received only normal saline. Subsequently, after weighing the animals, the weights of testes, dimensions of the testis, and the serum testosterone concentration were measured in six mice belonging to each group. After tissue processing, the samples were stained with hematoxylin and eosin, then the leydig cells were counted. In order to assess male fertility in each group, 3 male mice were chosen and each of them was kept with three female mice in a separate cage. After 10 days, the fertility rates of the male mice were determined by counting the number of embryos in uterus and the corpora lutea in their ovaries. RESULTS: The results of this study revealed that prescription of different doses of MPH can cause a significant decrease of the body weight. It reduces the number of leydig cells, too (p<0.01). Moreover, serum testosterone concentration (67.72±8.24 ng/ml in control group and 0.302±0.416 ng/ml after treatment with 2 mg/kg/day MPH) and fertility rate (95.42%±4.68% in control group and 64.96%±18.51% after treatment with 2 mg/kg/day MPH) of the male mice declined significantly in the treated groups compared with the control group (p<0.01), but it did not cause any changes in the weight or morphometric parameters of testes. CONCLUSION: The results of this study confirmed that MPH can negatively affect serum testosterone concentration and fertility rate of the male mice by decreasing the number of leydig cells and reducing the body weight.