Riadh Badraoui

Endocrine disruption and ovarian morphometric responses in rats following exposure to tetradifon.

We have investigated whether exposure to tetradifon causes ovary injuries, disrupts folliculogenesis in rat and whether ovary hormones (estrogen and progesterone) to be affected by this endocrine-active agent. Female rats were exposed orally to a dose of 28.9 mg/kg/day for 6 or 12 weeks. After sacrifice, ovary glands were examined for morphometric changes. The serums were used to determine levels of 17beta-estradiol and progesterone. Results showed no sign of toxicity. However, tetradifon promoted a significant increase in the percentage of atretic follicles in the 12-weeks treated rats. Number and the diameter of mature follicles (tertiary and preovulatory) were markedly diminished together with a reduction of the relative weight of ovaries. Compared with controls, the treated rats exhibited significant reduction in serum 17beta-estradiol and progesterone levels. These results suggest an endocrine disruption by tetradifon which may interfere with ovarian follicles development in rat.

Effect of alpha tocopherol acetate in Walker 256/B cells-induced oxidative damage in a rat model of breast cancer skeletal metastases

The pathophysiological changes and the oxidative-antioxidative status were evaluated in the bone microenvironment of rat inoculated with Walker 256/B mammary gland carcinoma cells, and used alpha-tocopherol acetate (ATA) as a countermeasure. Walker 256/B cells were injected into the right femora of aged male rats. Animals were randomized into three groups: 12 rats were injected with saline (control group); 14 rats were injected with Walker 256/B cells (5x10(4)) in the medullar cavity (W256 group); 14 rats were inoculated with Walker 256/B cells and treated with ATA (45mg/kg BW) (W256+ATA group). After 20 days, rats were euthanized and the femurs were radiographed. Micro architectural parameters were measured by microcomputed tomography and histology. Serum, bone and bone marrow were evaluated for oxidative damage. In parallel, cell cultures were done in the presence of ATA and ROS were measured by fluorescence; apoptotic cells were determined in parallel. W256 groups had osteolytic damages with marked resorption of cortical and trabecular bone. W256+ATA animals presented marked osteosclerotic areas associated with tumor necrosis areas inside the bone cavity. Levels of lipid peroxidation and protein oxidation were found to increase in W256 rats; a significant reduction in SOD and GSH-p activities was also observed. W256+ATA group had significantly reduced oxidative damage, but not reversed back to the control levels. The present study shows that Walker 256/B cells induce skeletal metastases associated with oxidative damage in the bone microenvironment. ATA reduced the oxidative stress damage, enhanced osteosclerosis and tumor cell apoptosis both in vitro and in vivo.

Biologic response to carbonated hydroxyapatite associated with orthopedic device: experimental study in a rabbit model.

Background Carbonated hydroxyapatite (CHA) and related calcium phosphates have been studied for many years as implant materials due to their similarity with the mineral phase of bone. The main limitation of CHA ceramics as well as other bioactive materials is that they have poor mechanical proprieties. It is thought that the mechanical device can cause an increase in metabolic activity and bone healing. In this study we investigated the reactivity and tissue behaviour of implanted CHA biomaterial reinforced by mini external fixator. Methods The evaluation of biomaterial biocompatibility and osteogenesis was performed on a rabbit model over a period of 6 weeks by radiological, histological and scanning electron microscopy (SEM) coupled with energy dispersive X-ray SEM-energy-dispersive X-ray (EDX) analysis. Results While rabbits treated with CHA exhibited more bone formation, and fibrous tissue was observed when empty bone defects were observed. EDX analysis detected little calcium and phosphorus on the surface of the bone that was not implanted, while high content of calcium (62.7%) and phosphorus (38%) was found on the interface bone cement. Conclusions Bone repairing showed that the mini external fixator stimulated the ossification which was pushed when grafted by CHA. This effect may play an important role in the prevention of implant loosening.

Protective effects of Teucrium polium aqueous extract and ascorbic acid on hematological and some biochemical parameters against carbon tetrachloride (CCl4) induced toxicity in rats

Herbal drugs play a crucial function to protect organisms from the toxic effect of some compounds. The present study was designed to evaluate the protective effects of Teucrium Polium (TP) aqueous extract and vitamin C (Vit C) against carbon tetrachloride (CCl4) which induced toxicity in rats. Male albino Wistar rats were divided into six groups: group I was used as controls, group II received CCl4 in olive oil (0.5ml/kg) by gavage, and group III received CCl4 in olive oil (0.5ml/kg) by gavage after three days of receiving TP (5g/l), orally, for seven days; Group IV received TP (5g/l) alone, orally, for seven days, Group V received CCl4 in olive oil (0.5ml/kg) by gavage after three days of receiving Vit C (250mg/kg) by intramuscular injection and Group VI received Vit C (250mg/kg) alone by intramuscular injection, for day seven. Some biochemical and hematological parameters were investigated. Our results showed that the administration of CCl4 caused hepatotoxicity as monitored by the significant increase in the levels of hepatic markers enzymes (lactate dehydrogenase (LDH), Alkaline phosphatase (PAL), total bilirubin (TB) and Gamma glutamyl transferase (γGT) levels) and a decrease in hematological parameters such as white blood cell (WBC), red blood cell count (RBC), mean corpuscular hemoglobin concentration (MCHC) and blood platelet count (PLT). Treatment with TP or Vit C appeared to be effective against hematotoxic and the liver changes induced by CCl4, as evidenced by the improvement of the parameters cited above. The CCl4-treated group demonstrated a significant increase of malondialdehyde (MDA) levels in erythrocytes thus causing a reduction in antioxidant defense system. Pretreatment with TP or Vit C improved the biochemical analyses, hematological parameters, and antioxidant defense system.

Nephrotoxic effect of tetradifon in rats: A biochemical and histomorphometric study

The effects of subchronic exposure to tetradifon on biochemical related kidney toxicological parameters [creatinine (CRT), urea, and uric acid (UA)] were examined. Oxidative stress in kidney tissue was also assessed by measuring vitamin C (VitC) content and antioxidant enzyme activities [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)]. Tetradifon was administered orally to 12 rats at a cumulative dose of 24.3 mg/kg for 12 weeks. Twelve additional rats, no treated, have served as control. Control and treated animals were sacrificed after 6 or 12 weeks. For each group, kidneys were examined for morphometric changes. Results showed that tetradifon induced significant increases in CRT and urea, and decrease in UA. Morphometrically, while mean glomerular volume decreased percentage of sclerosed glomeruli increased in treated rats. Index of interstitial fibrosis was significantly higher. Moreover, renal antioxidant enzyme (SOD and GPx) activities and VitC content decreased. We concluded that tetradifon possessed nephrotoxic by promoting kidney morphometric and functional damage and depleting renal antioxidant defense system in rats.

Erythrocytes oxidative damage and hematological effects of 2,4,4',5-tetrachlorodiphenyl sulfone in rats.

The effects of subchronic exposure to tetrachlorodiphenyl sulfone (TCDS) on hematological parameters [white blood cells (WBC), red blood cells (RBC), mean cell volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), hemoglobin (Hb) and hematocrite (Ht) levels] were examined. Oxidative stress in erythrocytes was also assessed by measuring thiobarbituric acid reactive substances (TBARS) and enzyme antioxidant activities [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)]. TCDS was administered orally, dissolved in water, ad libitum to 12 female rats at 28.9 mg/kg/day for 6 or 12 weeks. Results showed that TCDS induced significant decreases in RBC, Hb, and Ht. Whereas MCV, MCH, and MCHC remain unchanged and WBC increased only in the second period of the study. Moreover erythrocyte TBARS level increased, and antioxidant enzyme (SOD, GPx, and CAT) activities decreased. We concluded that TCDS intoxication promotes erythrocyte oxidative damage and disrupt hematological constituents in rats.