[Experimental study of the effects of cooking methods on tilmicosin residues in chicken]

Antibiotic residue in food is a major concern from a health point of view. Post-slaughter and pre-consumption processing such as cooking could affect residue. The purpose of this study is to survey the effect of boiling and microwave on tilmicosin in chicken. Chicken samples containing different tilmicosin amounts cooked in boiling water and in the microwave. After cooking, tilmicosin amount was determined by HPLC and its reduction percent amount due to cooking was calculated. Sample temperature and weight reduction amount were determined after cooking. Boiling and microwave resulted in significant tilmicosin reduction. In boiling method tilmicosin reduction percentage became more by time increase; however, it was inversely related to tilmicosin initial concentration. There was significant and positive correlation between sample central temperature and tilmicosin reduction percentage. In microwave mehod, tilmicosin reduction percentage was not influenced by time or tilmicosin initial concentration. Tilmicosin reduces during cooking and its reduction amount is different in various cooking method and, therefore surveillance data obtained from tilmicosin concentrations in raw tissue such as meat are not directly applicable for consumer exposure and dietary intake calculations when the whole cooked product is consumed

[Metformin reduces cisplatin-mediated apoptosis in gastric adenocarcinoma cells]

Metformin, a drug widely used for type 2 diabetes, may also have anti-cancer properties. The purpose of this study was to examine the effect of metformin on cisplatin cytotoxicity in the gastric adenocarcinoma cells line [MKN45]. In this study, cells viability and apoptosis were measured using the [3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide] assay and flow cytometry, respectively. Moreover, the expressions of mammalian target of rapamycin, survivin and AKT genes were evaluated by RT-PCR. All experiments were performed in triplicate. The results showed that each of metformin and cisplatin separately reduced the viability of cancer cell, but in co-administration, metformin reduced the cytotoxicity of cisplatin. In co-administration, the survivin expression was increased followed by a reduction in cisplatin anti-cancer effect. Therefore, the antagonistic effect of drugs can be associated with survivin expression. The results also revealed that the anti-apoptotic effects of metformin co-administrated with cisplatin are associated with increased AKT expression. It seems that in gastric cancers, metformin is not an appropriate choice to make cells sensitive to cisplatin and the antagonistic effects of the two drugs should be considered when they prescribed in combination

[Morphometrical and histometrical study on Syrian mice testis treated with pure phenol]

Phenol is a toxic organic chemical found in many foods and chemicals in our environment. Regarding to the wide use of phenol and its harmful effects, this study was done to determine the effect of pure phenol on morphometrical and histometrical structure of testis. 24 mature male Syrian mice divided to one control and 3 treatment groups that received pure phenol at 30, 75 and 100 mg/kg doses through gavage during 35 days. Finally, body, testis and tunica albuginea layer weight, gonadosomatic index [GSI] and length, width and thickness of the testis were measured. For histometrical assessment, the diameter of seminiferous tubules and the thickness of germinal layer were measured. Body weight in 75 and 100 mg/kg doses [2.02 +/- 4.09 and 2.33 +/- 3.35g, respectively] had significant decrease [p<0.05] comparing with control group [10.16 +/- 3.97g]. The difference in weight, length, width and thickness of testis between treated groups and control group was not significant, but the GSI in 30, 75 and 100 mg/kg doses [0.53 +/- 0.11, 0.53 +/- 0.07, 0.5 +/- 0.07%, respectively] had significant increase [p<0.05] comparing with control group [0.088 +/- 0.0083%]. Weight of tunica albuginea layer had increased significantly [p<0.05] only at dose of 75 mg/kg [0.01 +/- 0.006g] comparing with control group [0.002 +/- 0.002g]. There were significant differences [p<0.05] in diameter of seminiferous tubules in control group [100.42 +/- 12.41 micro m] comparing with 30 mg/kg [130.18 +/- 49.14 micro m] and 75 mg/kg doses [156.89 +/- 53.36 micro m] and thickness of germinal layer in control group [47.96 +/- 18.42 micro m] comparing with 30 mg/kg [37.18 +/- 14.44 micro m] and 75 mg/kg [30.13 +/- 50.04 micro m] doses. Pure phenol can cause changes in body weight, GSI and histometrical structure of testis

effect of sodium arsenite in induction of protein stress in chicken embryo model

Arsenic is one of the most important current environmental toxicants. Arsenic is one of the biggest protein stress inducer in several organs and systems. One of the basic and sensitive criteria for following protein stress is assessing carbonyl and thiol groups of proteins. Therefore, we assessed protein stress that produced by sodium arsenite in chicken embryos by measuring carbonyl and thiol proteins. After 4 days of incubation, 36 fertilized eggs were candled. The eggs that had alive embryos received a single injection of 0.1 and 0.5 ppm arsenite sodium in two separate groups of 12 eggs and the rest 12 [control group] received 0.5 ml saline into the yolk sac. After 20 days of incubation, teratogenicity and external defects in embryos were investigated, one ml of embryo blood was analyzed for assaying protein thiol and carbonyl as well. Data were analyzed by SPSS [version 16] with ANOVA test [tukey]. The mean of carbonyl protein was in 0.1 ppm group 0.835, 0.5 ppm group 0.844 and control group 0.804 and this change was significant and dose dependent. In addition, the mean of thiol protein was in 0.1 ppm group 0.053, 0.5 ppm group 0.014 and control group 0.054 and this change was also significant and dose dependent. The carbonyl and thiol protein alterations in serum of embryos exposed to arsenite sodium, suggest the embryotoxicity of this agent induction of plasma carbonyl and thiol protein stress