Effects of in utero benzo[a]pyrene exposure on the testis of rats during puberty and the protective effect of atorvastatin.

Benzo[a]pyrene (BaP) is a contaminant that is generated in the environment through processes such as smoke, incomplete combustion of fossil fuels, vehicle exhaust emissions, entry into the body is through inhalation, and consumption of contaminated food. It is an omnipresent environmental pollutant with unavoidable exposure. BaP metabolites are observed in the male reproductive system, especially in the testes and epididymis of animals, and are responsible for reduced testicular and epididymal function. The protective effect of atorvastatin (ATV) on testicular damage was investigated previously. The aim of the present study was to investigate the protective effect of ATV on testicular toxicity induced by benzo[a]pyrene (BaP) during pregnancy in Wistar rats. This experimental laboratory study involved 40 adult rats, divided into seven groups and maintained under standard environmental conditions. The groups received different diets [control, corn oil, ATV (10 mg/kg), BaP (10 and 20 mg/kg), and ATV + BaP (10 and 20 mg/kg)] at gestation Days 7-16, orally. Male offspring were examined 10 weeks after birth. Testis and serum samples were collected, and testosterone level, malondialdehyde (MDA), and glutathione (GSH) were measured. Histological and immunohistochemical assays were performed under a light microscope. Statistical analysis was conducted using SPSS, with analysis of variance and Tukey tests to assess significant differences between groups. ATV significantly reduced MDA, a marker of lipid peroxidation and oxidative stress in rat testes following BaP administration. Treatment with ATV at doses of 10 mg/kg increased GSH levels, correcting disruptions in the antioxidant system caused by BaP. Testosterone concentration in rats treated with ATV and BaP substantially prevented the decrease induced by BaP. Histomorphometry revealed that ATV significantly prevented the detrimental effects of BaP on the thickness of spermatogenic epithelium and the diameter of seminiferous tubules. Under ATV treatment, testicular tissue histopathology improved, and spermatogenesis returned to a almost back to normal state. Caspase-3 expression decreased, and apoptosis activity in testicular tissue improved under ATV treatment, indicating a positive effect of ATV in reducing apoptotic damage caused by BaP. In conclusion, exposure to BaP can induce oxidative stress-related damage to testicular tissue, as evidenced by an increase in MDA levels, which ATV treatment can mitigate. Additionally, ATV enhances intracellular antioxidant GSH and protects the testes against BaP-induced damage while increasing testosterone levels, which are reduced due to exposure to BaP.

Piperine mitigates oxidative stress, inflammation, and apoptosis in the testicular damage induced by cyclophosphamide in mice.

Although cyclophosphamide (CP) has been approved as an anticancer drug, its toxic effect on most organs, especially the testis, has been established. Piperine (PIP) is an alkaloid that has antioxidant, antiapoptotic, and anti-inflammatory activities. This study was investigated the protective effects of PIP on CP-induced testicular toxicity in the mice. In this experimental study, 48 adult male BALB/c mice (30-35 g) were divided into six groups (n = 8), receiving normal saline (C), 5 mg/kg of PIP (PIP5), 10 mg/kg of PIP (PIP10), 200 mg/kg of CP, 200 mg/kg of CP + PIP5, and 200 mg/kg of CP + PIP10. On the eighth day of the study, blood and testis samples were prepared for serum testosterone hormone quantification, sperm analysis, histological, and immunohistochemical assays. The results of this study showed that CP induced testicular toxicity with the decrease of sperm count, motility, and viability. Also, CP treatment caused histological structure alterations in the testis, including exfoliation, degeneration, vacuolation of spermatogenic cells, and reducing the thickness of the epithelium and the diameter of the seminiferous tubule. In addition, CP decreased glutathione (GSH) levels, increased malondialdehyde (MDA) levels, Caspase-3, and NF-κB. At the same time, PIP treatment reduced testicular histopathological abnormalities, oxidative stress, and apoptosis that were induced by CP. These results showed that PIP improved CP-induced testicular toxicity in mice, which can be related to its antioxidant, antiapoptotic, and anti-inflammatory activities.

Protective effects of sinapic acid against cyclophosphamide-induced testicular toxicity via inhibiting oxidative stress, caspase-3 and NF-kB activity in BALB/c mice.

Cyclophosphamide (CP), as a chemotherapeutic agent, with the generation of oxidative stress leads to testicular toxicity. Sinapic acid (SA), as a phenylpropanoid compound has therapeutic activities. This research was planned to evaluate the improving effects of SA versus testicular injury induced by CP. Forty-eight mice were distributed into six groups: untreated, SA (5 and 10 mg/kg), CP (200 mg/kg) and CP + SA (5 and 10 mg/kg). SA was administrated for 7 successive days and CP was administered intraperitoneally on the 3rd day of study. On the 10th day of research, testicular toxicity was evaluated by sperm parameters test, tissue (oxidative stress parameters) and serum (testosterone) biochemical, histopathological, and immunohistochemical (Caspase-3 and NF-kB) assays. The findings illustrated that CP induces atypical appearance in tissue structure, disorder of sperm parameters dysfunction, decrease of testosterone, oxidative stress (an increase of MDA and decrease of GSH), apoptosis and inflammation in testicular tissue. SA administration protected testis from oxidative stress and improves testosterone level and structure. Moreover, immunohistochemical findings also showed that SA can inhibit Caspase-3 and NF-kB activity. Data have confirmed that SA could protect testis structure and its functions against CP-induced injury through antioxidant, anti-inflammatory and anti-apoptotic activities.

Comparative evaluation of the effect of three types of fixatives (formalin, Bouin and Carnoy) on histomorphological features of various viscera.

Tissue shrinkage is one of the problems in preparing tissue sections. This study compares the use of 10% formalin, Bouin and Carnoy as fixatives on several mouse tissues to determine histomorphological features. In this experimental study, liver, kidney, heart, lung, testicle, spleen, brain and cartilage tissues were isolated from five BALB/c mice. Then, they were fixed with three types of fixatives. After dehydrating, clarifying and embedding, all samples were stained with haematoxylin and eosin. Then, the tissue structure of the viscera was evaluated qualitatively. The results showed that each fixative is more suitable for evaluating a specific part of the tissue. However, relative shrinkage appeared in the tissue sections fixed with 10% Formalin, (1) in the heart as spaces between muscle fibre bundles, (2) in the liver as the dilation of the liver sinusoidal spaces, (3) in the kidney tissue as the expansion of the lumens of the convoluted proximal and distal tubules, (4) in the spleen as open spaces inside the red and white pulps and (5) in the brain as an increase in the space between the cells of the granular and pyramidal cell layers of the cortex. In tissues that were soft and fragile, such as testis, liver and brain, Bouin's fixative was more suitable. Carnoy's fixative was more suitable for the spleen and kidney tissue. Based on the study results, formalin and Bouin were more suitable for heart and cartilage tissue. Considering that in the histopathological evaluation both the cytoplasm and the nucleus are evaluated, it is suggested to choose the fixative suitable for the type of tissue.

Hepatotoxicity in young adult rat offspring after prenatal exposure to benzo(a)pyrene, and protective effect of atorvastatin.

OBJECTIVES: Benzo[a]pyrene (BaP) is an environmental contaminant that interrupts the antioxidant defense and thus leads to oxidative stress and DNA damage in the liver. Atorvastatin (ATV) for reducing cholesterol has antioxidant and anti-apoptotic activities. This study investigated the effects of prenatal exposure of BaP on liver toxicity and the protective role of ATV in reducing liver toxicity. MATERIALS AND METHODS: In this study, rats were distributed randomly to seven groups: I. Saline control; II. ATV (10 mg/kg); III. Corn oil; IV and V. BaP (10 and 20 mg/kg); VI and VII. ATV + BaP (10 and 20 mg/kg). BaP and ATV were administrated from gestation day 7-16 (GD7-GD16), orally. Ten weeks after the birth, female offspring were examined for oxidative stress markers, liver enzymes, and histology. RESULTS: Data revealed that BaP significantly induced oxidative stress (decreased glutathione and increased malondialdehyde level), and disrupted the tissue structure of the liver. Moreover, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase increased in the offspring. ATV treatment along with BaP during gestation was able to bring the antioxidant status and serum liver enzymes levels relatively close to normal. As well as, histological findings showed that ATV was able to improve liver tissue structure caused by BaP. CONCLUSION: Based on the above studies we concluded that ATV at a low dose during gestation was able to reduce liver damage caused by BaP with antioxidant properties.

Alleviation of cisplatin-induced hepatotoxicity by gliclazide: Involvement of oxidative stress and caspase-3 activity.

AIMS: Cisplatin (CP), as an effective alkylating agent, is widely used in cancer treatment, while hepatotoxicity is one of its side effects. Gliclazide (GLZ), as an oral hypoglycemic drug, has antioxidant and anti-inflammatory properties. This study was designed to investigate the protective effect of GLZ against CP-induced hepatotoxicity in mice. METHODS: In this experimental study, 64 adult male mice randomly were allocated into eight groups (8 mice/group). Control, GLZ (5, 10, and 25 mg/kg, orally), CP (10 mg/kg, single dose, intraperitoneally), and CP+GLZ (in three doses). GLZ was administrated for 10 consecutive days. CP was injected on the 7th day of the study. At the end of the experiment, hepatotoxicity was evaluated by serum and tissue biochemical, histopathological, and immunohistochemical assessments. RESULTS: The data were revealed that CP increased oxidative stress (increased MDA and reduced GSH), liver damage enzymes (ALT, AST, and ALP), and immunoreactivity of caspase-3 in liver tissue of CP-injected mice. Also, CP induced histopathological changes such as eosinophilic of hepatocytes, dilatation of sinusoids, congestion, and proliferation of Kupffer cells. GLZ administration significantly ameliorated serum functional enzyme and hepatic oxidative stress markers in CP-injected mice. In addition, the histological and immunohistochemical alterations were ameliorated in GLZ-treated mice. Of the three doses, 10 and 25 mg/kg were more effective. CONCLUSIONS: In conclusion, GLZ with its antioxidant, anti-inflammatory, and anti-apoptotic activities, can be suggested as a promising drug in the treatment of CP-induced hepatotoxicity.

Polymerization Shrinkage of Five Bulk-Fill Composite Resins in Comparison with a Conventional Composite Resin.

OBJECTIVES: The polymerization shrinkage of methacrylate-based composites is among the most important causes of failure of composite restorations. The manufacturers claim that bulk-fill composites have a lower polymerization shrinkage than conventional composites. This study aimed to assess the polymerization shrinkage of five bulk-fill composites in comparison with a conventional composite. MATERIALS AND METHODS: In this in-vitro experimental study, composite discs (n=30) were fabricated using everX Posterior (EXP), Filtek Bulk-Fill Posterior (FBP), SonicFill 2 (SF2), Tetric N-Ceram Bulk-Fill (TNB), X-tra fil (XF), and Filtek Z250 conventional composite at the center of a metal ring bonded to a microscope slide and were covered with a coverslip. This assembly was transferred to a linear variable differential transformer (LVDT). Light-curing (1200 mW/cm2) was performed from underneath the slide for 30 seconds. The deflecting disc method and LVDT were used to assess the dimensional changes of the samples (indicative of polymerization shrinkage) at 1, 30, 60, and 1800 seconds following the onset of light irradiation. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's test. RESULTS: The groups were significantly different regarding polymerization shrinkage (P<0.002). The polymerization shrinkage of the tested composites following the onset of light irradiation ranged from 0.19 to 3.03. EXP showed a significantly higher polymerization shrinkage than other composites at 30, 60, and 1800 seconds after light irradiation, while XF showed the lowest polymerization shrinkage at the aforementioned time points. CONCLUSIONS: The tested bulk-fill composites had a polymerization shrinkage similar to that of the conventional composite.

Comparison of Dentin Permeability After Tooth Cavity Preparation with Diamond Bur and Er:YAG Laser.

OBJECTIVES: The aim of this study was to compare the permeability of dentin after using diamond bur and Er:YAG laser. MATERIALS AND METHODS: Seventy-two recently extracted, intact, and restoration-free human permanent molars were used in this study. The samples were randomly divided into three groups of 24 each and class I cavities were prepared as follows. Group 1: High speed diamond bur with air and water spray. Group 2: Er:YAG laser. Group 3: Er:YAG laser followed by additional sub-ablative laser treatment. Each group consisted of two subgroups with different cavity depths of 2mm and 4mm. The entire cavity floor was in dentin. Two samples from each subgroup were observed under scanning electron microscope (SEM). The external surfaces of other samples were covered with nail varnish (except the prepared cavity) and immersed in 0.5% methylene blue solution for 48 hours. After irrigation of samples with water, they were sectioned in bucco-lingual direction. Then, the samples were evaluated under a stereomicroscope at ×160 magnification. The data were analyzed using two-way ANOVA and Tukey's HSD test. RESULTS: Two-way ANOVA showed significant difference in permeability between groups 2 and 3 (laser groups with and without further treatment) and group 1 (bur group). The highest permeability was seen in the group 1. There was no significant difference in dentin permeability between groups 2 and 3 and no significant difference was observed between different depths (2mm and 4mm). CONCLUSION: Cavities prepared by laser have less dentin permeability than cavities prepared by diamond bur.