RESUMO
Due to hygienic risks of mercury residues in food and marine originated supplements, measuring total mercury and methyl mercury contents of canned tuna as a highly consumable marine food product is essential. In this study, 40 canned Tuna fish (from Persian Gulf) were collected in 2015 and then flame atomic absorption spectrometer (FAAS) and thermo gas chromatography mass spectrophotometry were used to measure total mercury and methyl mercury, respectively. The results indicated that the average contents of total mercury and methyl mercury of the canned tunas, with 34.2 and 29.5 ppb decrements compared with 2009's measurement, were 177.4 and 143.7 ppb respectively. The highest concentration of the total mercury was 315.2 while it was 267.9 ppb for methyl mercury. This study showed that the content of the mercury in canned tunas of the Persian Gulf was less than the Maximum Residue Limit (MRL).
RESUMO
Background: Doxorubicin, by aggregating in bone marrow, causes genotoxic effects, and thus reduces the repair ability of cells. The present study was conducted as an in vitro evaluation of age effects on the cytotoxicity induced by doxorubicin in mesenchymal stem cells (MSCs). Methods: The MSCs of female BALB/c mice aged 1, 8, and 16 months were separated, characterized, and subsequently evaluated in cellular growth media. After 24 hours, exposure of the MSCs of the 3 groups of mice to doxorubicin (25, 50, 100, 200, 400, 800, 1200 nM) and cytotoxicity were assessed, and the sublethal dose was determined using flow cytometry technique and lactate dehydrogenase (LDH) release assay. Results: The IC50 values determined by flow cytometry for the separated MSCs of 1 young, 8 middle- aged, and 16 old mice were and respectively. Interestingly, the results of these 2 methods in determining cytotoxicity were in agreement, and a concentration of approximately 25 nM was considered to be the shared sublethal dose for different ages. Conclusion: The results indicated that MSCs of middle-aged mice were more resistant to the toxic effects of the drug. Besides, MSCs separated from the old mice were the most sensitive to chemotherapy and its side effects such as disruptions of cell proliferation and viability. These disruptions can be ascribed to the alteration of function and physiological processes with age. Determining proper concentration of doxorubicin drug to destruct cancerous cells based on age and individual sensitivity can minimize the amount of toxicity.
RESUMO
Extensive distribution of hazardous substances in food chain and the deleterious effect of their residues on public health are a great concern of the society. Chicken eggs, as one of the most popular food commodities, in different parts of Tehran (Iran) were analyzed for two groups of hazardous substances including some organochlorine pesticides (OC) such as aldrin, lindane, dieldrin, dichlorodiphenyltrichloroethane, heptachlor and endusulfan) and heavy metals namely mercury (Hg), arsenic (As), lead (Pb), copper (Cu), cadmium (Cd), nickel (Ni) and chromium (Cr). Gas chromatography- electron capture detector, hydride-generation atomic absorption spectrometry, cold- vapor atomic absorption spectrometry and conductively coupled plasma atomic optical spectrometry were used to determine the levels of OCs, As, Hg and the others, respectively. For OCs, the results revealed none of the levels were more than maximum residues levels (MRLs), but three of them (Aldrin, lindane and endusulphan) were detectable. Moreover, 100% of 50 eggs had heavy metals with levels higher than limit of detection of the procedure. The levels of Pb and Hg in all eggs and Cd in 47% of samples were more than MRLs. It seems that the regular national monitoring of egg producing chain specially the quality of chicken feed should be taken into account seriously in order to safeguard public general health.
