Safety assessment of transgenic maize CC-2 by 90-day feeding study in Sprague-Dawley rats.

Objective: The purpose of this study was to assess the safety of transgenic maize CC-2 through a 90-day feeding study in Sprague-Dawley rats. Methods: Transgenic maize CC-2 and its parental counterpart maize Zhengdan 958 were respectively incorporated into diets at levels of 70%, 35% or 17.5% (w/w) and were administrated to rats (n = 10/sex/group) for 90 days. An additional control group of rats (n = 10/sex/group) were fed with the AIN93 breeding diet. All formulated diets were nutritionally balanced. Results: There was no death and obvious toxic symptom in all rats. Food consumption, body weight, total food consumption rate, hematology, urinalysis, organ weight and organ coefficient were comparable between transgenic groups and the corresponding dose parental groups. There were significant differences of food consumption rate on some timepoint between high dose transgenic group and high dose parental group; male rats in high dose transgenic group showed significantly higher ALT/AST than high dose parental group on the middle or end of the experiment; but the differences showed no biological significance. There were no significant differences of other serum biochemistry parameters and pathological changes. Conclusion: The results in this study demonstrated that the transgenic maize CC-2 didn't cause any related toxicity in rats.

[Assessment of allergenicity of oryza sativa recombinant human serum albumin in BALB/c mice].

OBJECTIVE: To investigate the potential allergenicity of oryza sativa recombinant human serum albumin(OsrHSA)in BALB/c mice. METHODS: Eighty BALB/c mice were randomly divided into four groups i. e ovalbumin(OVA) positive control group, potato acid phosphatase(PAP) negative control group, Oryza sativa recombinant HAS(OsrHSA) group and solvent control group(phosphate buffer saline, PBS), respectively. Mice were administered by intraperitoneal injections of tested proteins and histamine levels in plasma and sIgE, sIgG, sIgG1, sIgG2 a, and tIgE antibody levels in serum were measured. RESULTS: Compared with the other groups, serum tIgE, sIgE, sIgG, sIgG1 and plasma histamine levels in the OVA group were significantly increased, while serum sIgG2 a levels were decreased(P<0. 05). There was no significant difference in serum sIgE level and histamine level between the OsrHSA group and the control group(P>0. 05). Serum sIgG, sIgG1 and sIgG2 a levels were lower than those in the PAP group(P<0. 05). There was no significant difference in serum tIgE content between PAP group and OsrHSA group(P>0. 05). CONCLUSION: The potential allergenicity of OsrHSA through traperitioneal injection in BALB/c mice was very low.

[Construction and identification of stable hFcεRIαßγ/RBL-2H3 cells for food allergy assessment].

OBJECTIVE: To establish an rat basophil leukemia(RBL)-2H3 cell line stably expressing human high affinity receptor containing alpha, beta and gamma chain(hFcεRIαßγ), in order to provide experimental materials for evaluating allergenicity of food. METHODS: The lentivirus was transfected into RBL-2H3 cells, and the mRNA expression of hFcεRIαßγ in cells was detected by real-time PCR and the protein expression of hFcεRIα was detected by flow cytometry. RESULTS: Sequencing result showed that recombinant lentiviral vector GV367-hFcεRIαßγ was successfully constructed. According to the result of experiments, lentivirus could effectively infect RBL-2H3 cells. The mRNA of hFcεRIαßγ and protein levels of hFcεRIα in RBL-2H3 cells were successfully overexpressed. CONCLUSION: The hFcεRIαßγ/RBL-2H3 cells were preliminarily constructed, which could be binded with human IgE and further used in the evaluation system of food allergy, compared to RBL-2H3 cells.