This study investigated the effects of thiamine pyrophosphate (TPP) at dosages of 10 and 20 mg/kg on oxidative stress induced in rat brain tissue with cisplatin and compared this with thiamine. Cisplatin neurotoxicity represents one of the main restrictions on the drug being given in effective doses. Oxidative stress is considered responsible for cisplatin toxicity. Our results showed that cisplatin increased the levels of oxidant parameters such as lipid peroxidation (thio barbituric acid reactive substance (TBARS)) and myeloperoxidase (MPO) in brain tissue and suppressed the effects of antioxidants such as total glutathione (GSH) and superoxide dismutase (SOD). TPP, especially at a dosage of 20 mg/kg, significantly reduced TBARS and MPO levels that increase with cisplatin administration compared with the thiamine group, while TPP significantly increases GSH and SOD levels. In addition, the level of 8-Gua (guanine), a product of DNA damage, was 1.7 ± 0.12 8-hydroxyl guanine (8-OH Gua)/105 Gua in brain tissue in the control group receiving cisplatin, compared with 0.97 ± 0.03 8-OH Gua/105 Gua in the thiamine pyrophosphate (20 mg/kg) group and 1.55 ± 0.11 8-OH Gua/105 Gua in the thiamine (20 mg/kg) group. These results show that thiamine pyrophosphate significantly prevents oxidative damage induced by cisplatin in brain tissue, while the protective effect of thiamine is insignificant.

SummaryBackgroundOxidative liver injury occurring with methotrexate restricts its use in the desired dose. Therefore, whether or not thiamine and thiamine pyrophosphate, whose antioxidant activity is known, have protective effects on oxidative liver injury generated with methotrexate was comparatively researched in rats using biochemical and histopathological approaches.Material/MethodsThiamine pyrophosphate+methotrexate, thiamine+methotrexate, and methotrexate were injected intraperitoneally in rats for 7 days. After this period, all animals’ livers were excised, killing them with high-dose anesthesia, and histopathologic and biochemical investigations were made.ResultBiochemical results demonstrated a significant elevation in level of oxidant parameters such as MDA and MPO, and a reduction in antioxidant parameters such as GSH and SOD in the liver tissue of the methotrexate group. Also, the quantity of 8-OHdG/dG, a DNA injury product, was higher in the methotrexate group with high oxidant levels and low antioxidant levels, and the quantity of 8-OHdG/dG was in the thiamine pyrophosphate group with low oxidant levels and high antioxidant levels. In the thiamine and control groups, the 8-OHdG/dG rate was 1.48±0.35 pmol/L (P>0.05) and 0.55±0.1 pmol/L (P<0.0001). Thiamine pyrophosphate significantly decreased blood AST, ALT and LDH, but methotrexate and thiamine did not decrease the blood levels of AST, ALT and LDH. Histopathologically, although centrilobular necrosis, apoptotic bodies and inflammation were monitored in the methotrexate group, the findings in the thiamine pyrophosphate group were almost the same as in the control group.ConclusionsThiamine pyrophosphate was found to be effective in methotrexate hepatotoxicity, but thiamine was ineffective.

In this study, the effect of mirtazapine on rat kidneys versus ischemia-reperfusion (IR) damage was biochemically and histopathologically investigated. The results have shown that malondialdehyde (MDA) level of healthy rat group is 15.2 mol/g protein. The level of this substance was measured as 26.7 mol/g in only ischemia group. The MDA levels of IR and mirtazapine + renal ischemia-reperfusion (MRIR) groups were 39 ± 17.6 mol/g protein. While myeloperoxidase activity of healthy rat group was 20.2 u/g, the activities of only ischemia, IR, and MRIR groups were 28, 36.3, and 21 u/g, respectively. The glutathione levels were measured as 17.7, 12.8, 7.5, and 16.2 nmol/g in healthy, only ischemia, IR, and MRIR groups, respectively. Finally, glutathione S-transferase activities of healthy, only ischemia, IR, and MRIR groups were determined as 20, 13.8, 7.1, and 18.3 u/g, respectively. Histopathologically, while hemorrhage in interstitial area was observed in only ischemia group, significant tubular epithelial swelling, necrosis, and cast accumulation were seen in IR group. In MRIR group, only mild tubular epithelial swelling and mild hyaline cast accumulation were observed in kidney tissue. Consequently, it can be said that mirtazapine has a protective effect on IR-induced kidney damage.

Cisplatin causes infertility due to ovarian toxicity. The toxicity mechanism is unknown, but evidence suggests oxidative stress. In this study, the effect of mirtazapine on cisplatin-induced infertility and oxidative stress in rats was investigated. 64 female rats were divided into 4 groups of 16. Except for the controls that received physiologic saline only, all were administered with cisplatin (5 mg/kg i.p.) and mirtazapine (15 mg/kg p.o.) or mirtazapine (30 mg/kg p.o.) for 10 days. After this period, six rats from each group were randomly selected, and malondialdehyde (MDA), myeloperoxidase (MPO), nitric oxide (NO), total gluthatione (tGSH), gluthatione peroxidase (GPx), superoxide dismutase (SOD), and 8-hydroxy-2 deoxyguanine (8-OH Gua) levels were measured in their ovarian tissues. Reproductive functions of the remaining rats were examined for 6 months. The MDA, MPO, NO groups and 8-OH Gua levels were higher in the cisplatin-treated groups than the controls, which was not observed in the mirtazapine and cisplatin groups. GSH, GPx, and SOD levels were reduced by cisplatin, which was prevented by mirtazapine. Cisplatin caused infertility by 70%. The infertility rates were, respectively, 40% and 10% for the 15 and 30 mg/kg mirtazapine administered groups. In conclusion, oxidative stress induced by cisplatin in the rat ovary tissue causes infertility in the female rats. Mirtazapine reverses this in a dose-dependent manner.

Our findings indicate that Kineret® might be useful in clinical practice for the treatment of damage that may occur as a result of ovarian torsion.

In this study, the biochemical and histopathological effects of thiamine and thiamine pyrophosphate on ischemia-reperfusion induced oxidative damage in rat ovarian tissue were investigated. Animals were divided into four groups of six rat each, ovarian ischemia-reperfusion (IR), 25 mg/kg thiamine + ovarian ischemia-reperfusion (TIR), 25 mg/kg thiamine pyrophosphate + ovarian ischemia-reperfusion (TPIR) and Sham group (SG). The results of the biochemical experiments have shown that the rat ovarian tissue with thiamine treatment, the level of MDA, GSH and the 8-hydroxyguanine are almost the same as the IR group; while in the group with thiamine pyrophosphate treatment, the level of MDA, GSH and the 8-hydroxyguanine are almost the same as the SG. Ovarian tissue of rats in the IR group were congested and dilated vessels, edema, hemorrhage, necrotic and apoptotic cells. In this group, the migration and the adhesion of the polymorphonuclear leucocytes to the endothelium were observed. Both ovaries in TPIR group, there was no difference according to the SG. Histopathology of ovarian tissues in the TIR group was almost the same with the IR group. Our results indicate that thiamine pyrophosphate significantly prevents the ischemia-reperfusion induced oxidative damage in ovarian tissue, whereas thiamine has no effect. In conclusion, we have found that thiamine pyrophosphate prevents oxidative damage due to ischemia-reperfusion injury, whereas thiamine does not have this effect. Furthermore, we have confirmed that the results of our biochemical analyses are in concordance with the histopathological findings.

Reperfusion has always been "the emergency intervention" to ischemic tissue. For a given period of time, tissue injury due to ischemia and reperfusion is more serious than injury due to ischemia only. Groups were as: Group 1: 25 µg/kg dexmedetomidine + ischemia/reperfusion group. Group 2: 10 mg/kg yohimbine +25 µg/kg dexmedetomidine + ischemia/reperfusion group. Group 3: Ischemia/reperfusion (control) group. Group 4: Healthy rats. Rat ovaries were exposed to a 3-hour ischemia and then reperfusion ensured for 2 hours. After ischemia/reperfusion, total glutathione, malondialdehyde, 8-hydroxyguanine levels and histopathological investigation were studied. The highest total glutathione and the lowest malondialdehyde and DNA damage levels were determined in dexmedetomidine group when compared to control group. The difference between yohimbine + dexmedetomidine and the control group was insignificant. Dexmedetomidine protects the ovarian tissue of the rat from I/R injury. It is hypothesized that this protective effect of dexmedetomidine is mediated by the α-2 adrenergic receptors. Dexmedetomidine could be useful for attenuation of tissue damage after I/R and prevention of I/R-related complications.

Aim Typical antipsychotics (TAPs) are commonly used to treat schizophrenia and bipolar disorder. However, extrapyramidal disorders, hyperprolactinemia, and reproductive dysfunctions have been observed in women during the use of TAPs. For this reason, less toxic and prolactin‐sparing atypical antipsychotic (AAP) drugs such as clozapine (CLN) have been developed. The aim of this study is to investigate the effect of taxifolin on possible ovarian and reproductive toxicity associated with CLN and haloperidol (HPL) in female Wistar albino rats. Methods The rats were grouped as healthy control group (HCG), CLN, HPL, taxifolin + clozapine (TCL), and taxifolin + haloperidol (THL). Drugs were administered to the groups for 28 days. At the end of that time, ovarian tissues of six rats from each group were taken for histopathological and biochemical analyses. Remaining six rats in groups were examined for evaluation of reproductive dysfunctions. Results Severe degeneration and vacuolization were observed in the primary, secondary, and primordial follicles of the ovarian tissues of CLN‐ and HPL‐treated groups, of which malondialdehyde (MDA) level was high and total glutathione (tGSH) level was low. In the taxifolin‐treated groups, taxifolin significantly prevented the increase of MDA level and decrease of tGSH level, and the severity of histopathological damage was found to be lower. In addition, it was found that taxifolin significantly prevented infertility and delay in pregnancy associated with CLN and HPL. Conclusions The results of this experiment suggest that taxifolin can be beneficial in treating oxidative ovarian damage, infertility, and reproductive dysfunctions induced by CLN and HPL.