Fertility protective effect of taxifolin in cisplatin-induced ovarian damage.

OBJECTIVE: The aim of our study was to investigate the protective effect of taxifolin on ovarian damage and reproductive dysfunction created by cisplatin administration. MATERIALS AND METHODS: A total of 36 albino Wistar female adult rats were equally divided into 3 groups as cisplatin administered only (CIS), taxifolin+cisplatin (T+C) and healthy control group (HG). Taxifolin 50 mg/kg was administered orally by gavage in the T+C (n=12) group. In the HG (n=12) and CIS (n=12) groups, the same volume of distilled water as a solvent was orally administered. One hour after administration of taxifolin or distilled water, animals in the T+C and CIS groups were injected with cisplatin at a dose of 2.5 mg/kg intraperitoneally. This procedure was repeated once a day for 14 days. Six animals from each group were sacrificed on day 15, and their ovaries were removed for histopathological and biochemical analysis. Ovarian tissue malondialdehyde (MDA), total Glutathione (tGSH), Nuclear Factor-Kappa B (NF-kB), Tumor Necrosis Factor-α (TNF-α), Interleukin 1 beta (IL-1ß), and Interleukin-6 (IL-6) levels were measured. The remaining animals (n=6 in each group) were kept in the laboratory with mature male rats for two months to breed. RESULTS: CIS administration led to an increase in inflammatory molecules and membrane lipid peroxidation products, and decreased the synthesis of antioxidant molecules. Compared to the CIS group, the ovarian tissue MDA, NF-kB, TNF-α, IL-1ß and IL-6 levels were found to be significantly decreased in the T+C group (p<0.001 for all comparisons). On the other hand, the tGSH levels of the T+C group were significantly higher than the CIS group (p<0.001). Milder ovarian necrosis, fibrosis and follicle damage were detected in animals which were given taxifolin. Four out of the six rats (67%) treated with taxifolin gave birth within 27 days. CONCLUSIONS: We demonstrated, for the first time, that taxifolin ameliorates cisplatin-induced ovarian injury by decreasing MDA and proinflammatory cytokines and increasing the antioxidant enzyme. The fact that more than half of the animals receiving taxifolin became pregnant suggests that the cytoprotective effect of taxifolin is strong enough to preserve fertility.

Quantification of tributyltin in seawater using triple isotope dilution gas chromatography-inductively coupled plasma mass spectrometry achieving high accuracy and complying with European Water Framework Directive limits.

A triple isotope dilution GC-ICPMS method for the determination of tributyltin (TBT) was developed and validated to meet the European Water Framework Directive (WFD) requirements. The validation procedure involved the evaluation of trueness, precision (repeatability, intermediate precision), limit of detection (LOD) and limit of quantification (LOQ), stability, measurement uncertainty and traceability studies. The method is one of the most sensitive methods published to date with good accuracy, 103% average recovery in the range with %RSDs of 2.8-6.7%. A LOD value of 0.015 ng L-1 for the TBT cation was achieved with a sample volume of 12 mL seawater. TBT was derivatized using 20 µL sodium tetraethylborate solution (0.05% NaBEt4) to make volatile for GC-ICPMS. Measurement uncertainty was in the range of 4.8-13% which was achieved through dissolution of tributyltinchloride (TBTCl) in 1-propanol, a low-volatility solvent combined with the use of a triple isotope dilution (ID) calibration technique. Isotope dilution calibration was performed by adding 117Sn isotopically enriched TBT to the seawater samples. The stability test results showed that TBT concentration was stable for three months in seawater samples after passing through a 0.2 µm filter and stored in amber glass bottles at 4°C. The response surface methodology (RSM) approach was successfully implemented to provide optimal conditions for large volume injection (LVI) to obtain the maximum analytical signal. The key variables selected in the experimental design were evaporation time, evaporation temperature, carrier flow, and injection speed. This method was applied to seawater samples collected from the Bay of Izmit, Kocaeli, Turkey, where TBT pollution has not been measured yet.

Traceable and accurate quantification of iron in seawater using isotope dilution calibration strategies by triple quadrupole ICP-MS/MS: Characterization measurements of iron in a candidate seawater CRM.

Accurate quantification of iron is crucial for the characterization of a candidate seawater certified reference material. Isotope dilution mass spectrometry as a primary method is one of the option for this purpose. In this study, triethylamine (TEA) assisted Mg(OH)2 co-precipitation is developed and combined with isotope dilution mass spectrometry for the characterization of candidate certified reference material, UME CRM 1206. The analytical protocol of co-precipitation was optimized to achieve reproducible yields of ~100% Fe with high salt rejection (residual salinity ~0.003%). Three calibration strategies, single, double and triple isotope dilution mass spectrometry (IDMS) coupled with co-precipitation were investigated in terms of metrological aspects. The determination of Fe was carried out by ICP-MS with tandem configuration (ICP-MS/MS) using NH3/He cell gas which was optimized for the minimum background equivalence concentration to be able to measure highly accurate 56Fe/57Fe ratio with the highest possible sensitivity. The background corrected typical procedural blank levels and limit of detection calculated based on three times the standard deviation of blanks were found as 9 ng/kg (0.16 nM) and 11 ng/kg (0.20 nM) for single IDMS, respectively. Trueness of the developed analytical methods has been demonstrated using CASS-6 and NMIA MX014 with complete and very precise recoveries. SI-traceable values with combined uncertainty (k = 2) were obtained for single, double and triple IDMS as (12.70 ±â€¯0.16) ng/g, (12.728 ±â€¯0.084) ng/g and (12.732 ±â€¯0.062) ng/g, respectively. The relative combined uncertainty for each approach was calculated as 0.64%, 0.33% and 0.24%, respectively.