Experimental and Toxicologic Pathology最新文献

Aims

Retinoic acid (RA) has a vital importance in order to ensure continuity and morphology in many tissues. Matrix metalloproteinases (MMPs) have significant roles in proliferation, the formation of cancers, and metastasis. In this study the effects of RA on MMP-2 production in cells of rat uterus were investigated.

Methods

Twenty-four adult Spraque Dawley rats were divided into two groups, the experimental group was treated with 40 mg/kg/day 13-cis RA for 5 days by gavage. Uterine tissue sections were treated with BrdU and MMP-2 antibodies, evaluated using light microscopy. Tissues were fixed with 2.5% glutaraldehyde and evaluated using transmission electron miroscopy.

Results

MMP-2 immunoreactivity decreased in the stromal cells compared with the control group and no staining of MMP-2 was observed in glandular epithelium in the experimental group. BrDU labeling of cells showed significant decrease in RA-treated group versus control group cells. Based on the electron microscopy evaluation, the surface epithelial cells of the experimental group showed vacuolization, and an accumulation of lipofuscin bodies was also observed in the gland epithelium. Cells involving autophagic vacuoles contained excess lipid granules in the entire uterus layers especially localized at the border of the endometrium and myometrium.

Conclusion

RA had negative effects on cell proliferation and cell morphology and inhibited MMP-2 expression.

The purpose of this study is to identify the potential of a two-dimensional preantral follicle culture as an in vitro model of predicting premature ovarian failure. The two-dimensional preantral follicles culture method was established by cultivating preantral follicles collected from ICR F1 hybrids (aged 12–14 days) for 12 days. The preantral follicles were incubated with 0.54 mg/ml cyclophosphamide, 0.5 mg/ml busulfan, 0.12 mg/ml cisplatin, 3.12 mg/ml 4-vinylcyclohexene diepoxide, 5 mg/ml D (+) galactose, and 0.5 mg/ml hydrocortisone for 24 h at culture days 2, 6 and 11. The diameter of follicles, the cumulus-oocyte complex number and the maturity of oocytes were recorded as the parameters to detect follicular maturation induced by the culture agents. The results indicated that, except for busulfan, D (+) galactose, and hydrocortisone, such test articles could significantly decrease follicular growth (p < 0.05 or p < 0.01), and induce oocyte degeneration and follicle atresia when the follicles were treated at day 2. With the exception of hydrocortisone, such agents also gradually decreased follicular development (p < 0.05 or p < 0.01) when the follicles were treated at day 6. All of the test articles but hydrocortisone can interfere with the ovulation, the cumulus-oocyte complex discharge and oocyte maturation of follicles when treated at days 2, 6 and 11. It is suggested that two-dimensional preantral follicle culture could be utilized as a potential in vitro system to mimic the POF model. It may also be employed in screening potential ovarian toxic agents, reducing laboratory animal use and promoting animal welfare.

Oxidative stress is one of a critical pathogenic factor in the progression of aging and chronic diseases such as cancer, myocardial inflammation and diabetes. In the present scenario, peptides with short half life and more biological specificities are gaining much attention as prodrugs. Thus, the present investigation carried out to screen potential antioxidative peptide, VLPVPQK to cope with the cellular oxidative damage. Our results showed that treatment of rat fibroblast cells with 0.2 mM H₂O₂ for 6 h significantly declined different oxidative stress biomarkers such as SOD, CAT, GSH, and promoted LDH activity. In addition, ROS and TNF-α levels were also increased upon H₂O₂ exposure for 6 h and thereby, it induced cell death. Amazingly, pretreatment of the peptide (VLPVPQK) significantly elevated cell survivability, by reversing all H₂O₂ induced alterations in fibroblast cells. Therefore, our results indicated that, the peptide (VLPVPQK) acted as a potential cytoprotective agent, who restored redox balance and cell homeostasis in cultured fibroblast cells, even after H₂O₂ exposure, suggesting that the peptide can be valuable as an effective remedy in treatment of oxidative stress related diseases and skin inflammation related disorders.

For scientific clarification of some traditional uses, this study was designed to explore the antioxidant, cytotoxic and antineoplastic properties of leaf extract of Carissa carandas Linn., a traditional medicinal plant of Bangladesh. The methanol extract of Carissa carandas leaves (MELC) was applied on DPPH and ABTS experiments to determine its antioxidant activity. In vitro the cytotoxic effect of MELC was evaluated against colonic adenocarcinoma cell lines (SW-480 and SW-48) whereas in vivo its antineoplastic property was tested against Ehrlich ascites carcinoma (EAC). The DPPH and ABTS assays revealed the antioxidant activity of MELC with IC₅₀ 10.5 ± 1.2 and 1.75 ± 0.3 μg/ml that was comparable to L-ascorbic acid. In vitro cytotoxic study, MELC reduced the viability of adenocarcinoma cells in dose dependent manner and in vivo, administration of MELC (25 mg/kg) resulted in a significant (p < 0.05) decrease in viable EAC cell count thereby increasing the life span of the EAC cell bearing mice. Restoration of hematological parameters such as red blood cells (RBC), hemoglobin and white blood cells (WBC) to normal levels in MELC-treated mice was also observed. Moreover, treatment with MELC induced apoptosis of EAC cells as observed in fluorescence microscopic view of DAPI (4,6-diamidino-2-phenylindole) stained cells and also increased p53 gene expression MELC-treated cells in respect to untreated EAC control. In addition, the MELC was rich in polyphenol content and its GC–MS chromatogram confirmed the presence of some compounds all of which showed anticancer and cytotoxic activities in previous studies. In a word, this study supports the use of Carissa carandas in traditional medicine as well as highlights the need to further explore the potentials of MELC as an antineoplastic agent.

Chicken egg fetal livers were evaluated for histopathological changes produced by four genotoxic hepatocarcinogens: 2-acetylaminofluorene (AAF), aflatoxin B₁ (AFB₁), benzo[a]pyrene (BaP), diethylnitrosamine (DEN); four structurally related non- or weakly- carcinogenic comparators: fluorene (FLU), aflatoxin B₂ (AFB₂), benzo[e]pyrene (BeP), N-nitrosodiethanolamine (NDELA); two epigenetic hepatocarcinogens: clofibric acid (CFA), phenobarbital (PB); and the non-carcinogen, D-mannitol (MAN). CFA, PB and MAN were also assessed for formation of DNA adducts using the ³²P nucleotide postlabeling (NPL) assay and for DNA breaks using the comet assay. CFA was also assessed in enhanced comet assay for oxidative DNA damage induction. Eggs were dosed on days 9- 11 of incubation. For genotoxicity evaluation, livers were collected 3 h after the last dose. Liver qualitative histopathology assessment was performed on days 12 and 18 of incubation. CFA was negative for DNA adducts but yielded clear evidence of DNA breaks due to oxidative stress. PB and MAN produced no DNA adducts or breaks. Liver to body weight ratios were not affected in most groups, but were decreased in DEN groups, and increased after PB dosing. Livers from control groups, FLU, AFB₂, BeP, NDELA, CFA, and MAN groups, displayed a typical hepatocellular trabecular pattern at both time points. In contrast, the four genotoxic carcinogens induced time- and dose- related interference with fetal liver cell processes of proliferation, migration and differentiation, leading to hepatocellular and cholangiocellular pleomorphic dysplasia and re-(de-) differentiation with distortion of the trabecular pattern. In addition, dosing with the high dose of DEN produced gallbladder agenesis. PB induced hepatocellular hypertrophy, interference with migration, expressed as distortion of the trabecular pattern, and a moderate cholangiocellular dysplasia. In summary, histopathological analysis of chicken fetal livers revealed developmental anomalies, as well as genotoxicity-induced and, in the case of PB, adaptive morphological changes. Thus, the model provides histopathological outcomes of molecular effects.

Aminoglutethimide is a steroidogenesis inhibitor and inhibits a cholesterol side-chain cleavage enzyme (CYP11A1) that converts cholesterol to pregnenolone in mitochondria. We investigated histopathological changes induced by 5-day administration of AG in mice. Cytoplasmic vacuoles of various sizes and single cell necrosis were found in zona fasciculata cells in AG-treated mice. Some vacuoles were positive for adipophilin, whereas others were positive for lysosome-associated membrane protein-2 on immunohistochemical staining, indicating they were enlarged lipid droplets and lysosomes, respectively. Electron microscopy revealed enlarged lysosomes containing damaged mitochondria and lamellar bodies in zona fasciculata cells, and they were considered to reflect the intracellular protein degradation processes, mitophagy and lipophagy. From these results, we showed that AG induces excessive lipid accumulation and mitochondrial damage in zona fasciculata cells, which leads to an accelerated lysosomal degradation in mice.

Background

Nicotine (Nic) is a major risk factor in the development of functional disorders of male reproductive system. Achillea millefolium; is highly regarded for medicinal activities, due to its antioxidant and anti-inflammatory properties. This study was carried out to evaluate whether Achillea millefolium (Achm) inflorescences alcoholic extract could serve as a protective agent in male reproductive male failures during Nic exposure in a rat model.

Methods

Twenty-five adult male Wistar rats were categorized into the five groups. Tests 1 and 3 groups were received Nic at dose levels of 0.2 and 0.4 mg/kg BW/day, respectively by IP injection. Tests 2 and 4 groups were received Nic at the same doses along with Achm at dose level of 120 mg/kg BW/day. The study period took forty-eight days for all experimental groups.

Results

Nic groups showed significant decreases in tubule differentiation index (TDI), sperm count, motility, stereological parameters and an increase in dead and abnormal sperms. Moreover, the reduction in total antioxidant capacity (TAC), superoxide dismutase (SOD) activity, serum levels of FSH, LH and testosterone, along with increased serum concentration of LDH were observed in the Nic groups. Total nitrite and malondealdehyde levels increased and total thiol molecules (TTM) levels decreased in testicular tissue in the Nic groups. Notably, Achm co-administration caused a contemporary recovery in above-mentioned parameters.

Conclusion

Nic exerts major toxicity in testicular tissue and causes damages in several ways including, oxidative stress, whilst Achm imposes protective effect against Nic-induced reproductive failure, which may attribute to its antioxidant capacity.

Aims

Laminaria Japonica Polysaccharides (LJP) is a kind of plant polysaccharide isolated from Laminaria Japonica Aresch. LJP has a variety of biological activity, including anti-tumor, improving immune function, anti-radiation and others. This study observed the biological activity of LJP in vitro and in vivo on human nasopharyngeal carcinoma(NPC), and the possible anticancer mechanism was explored.

Methods

Nasopharyngeal poorly differentiated squamous cell carcinoma cell lines CNE2 and HONE1 were used for the study. MTT method was used to detect the proliferation of HONE1 and CNE2 treated with gradient concentrations of LJP. The apoptosis of HONE1 treated with LJP was detected by annexin V-FITC/PI double staining method. HONE1 was used to establish subcutaneous implanted tumor model in nude mice. The changes of transplanted tumor volume and body weight of nude mice in each group were observed and recorded. The changes of the ultrastructure of transplanted tumor were observed by transmission electron microscope (TEM).

Results

MTT results showed that LJP has inhibitory effect on proliferation of both HONE1 and CNE2, and the effects were dosage-dependent; results of flow cytometry (FCM) analysis showed that, LJP could efficient induce apoptosis in HONE1, and apoptosis rate increased with the increase of LJP concentration. In vivo experiments, the inhibition rate was 33.7% (P < 0.05) and 47% (P < 0.01) in middle and high dose LJP group, respectively. TEM results suggested that the cancer cells in the transplanted tumor tissue treated with middle and high dose LJP presented unique apoptosis changes.

Conclusions

LJP can effectively inhibit the growth of NPC cells. And it may be achieved by inducing apoptosis of NPC cells.

We investigated the effects of adding of monosodium glutamate (MSG) to a standard diet on oxidative stress in kidney, nitric oxide excretion, renal ions handling and blood pressure. We examined the association of these changes with the effects on renal histology. The study was performed on male Wistar rats (5 weeks old) divided into 3 groups: 1) MSG group were fed a diet supplemented with 3 g of MSG/kg b.w./day, five days a week, and spontaneous ingestion of a 1% MSG solution during 16 weeks; 2) NaCl group were fed a diet with NaCl (1 g/kg b.w./day) and 0.35% NaCl solution permanently alone at the same frequency and time; 3) control group were fed the normal chow and tap water. Sodium, potassium, calcium, phosphorus, creatinine, protein and nitric oxide excretion were analyzed in urine. We utilized clearance techniques to examine glomerular filtration rate and cortical renal plasma flow. We determined the oxidative state and the histopathological changes of renal tissue.

Following MSG treatment, absolute and fractional sodium and potassium excretion decreased although there was hyperfiltration. The MSG group showed similar increase in blood pressure than the NaCl group, but nitric oxide excretion was significantly reduced. Although no increase in lipid peroxidation was verified, its observed alteration in the reduced glutathione/oxidized cycle and their enzymes GPx and GR. These changes were accompanied by alterations histological both glomerular as well as tubular level and by interstitial fibrosis with mononuclear cells accumulation.

These results indicate that the addition of MSG in the diet decreases the excretion of Na, K and water with hyperfiltration. NaCl retention that leads to hypertension was accompanied by renal pathologic changes, intrarenal oxidative stress and reduction of nitric oxide excretion.

Gingko biloba leaves have been used as herbal medicine in China for 5000 years, and the standardized leaf extract (GB-STE) has some beneficial effects in the treatment of age-related, cardiovascular, and neurological diseases. The aim of this study was to investigate the renoprotective effects of the Gingko biloba extract (GbE) against the toxicity of a single and relatively low dose of carbon tetrachloride (CCl₄). In male adult Wistar rats, we determined the urine flux, the concentration of total proteins in urine, the concentration of glucose in urine, and the concentration of malondialdehyde (MDA) in renal cortex as well as two markers of renal function (clearance of inulin and p-aminohippurate); we also compared the histological lesions caused by CCl₄. Carbon tetrachloride increased the urinary concentration of total proteins, and the renal concentration of MDA; however, it did not modify the urine flux, urinary concentration of glucose, nor the inuline or the p-aminohipurate clearances. Morphologically, CCl₄ generated some tubular damage that was more intense in the inner cortex of kidneys. The GbE extract counteracted the effects of CCl₄ on the concentration of total proteins in urine, the concentration of renal MDA, and the renal histological changes. In conclusion the main toxic effects produced by CCl₄ were prevented by the GbE, probably due to their antioxidant properties and the inhibition of the main P450 isoenzyme (CYP2E1) that metabolize CCl₄.