Crop Biotech Update

Scientists Study the Effect of Bt Rice on Swiss Rats

December 4, 2013

Hunan Agriculture University scientist Yang Wang and colleagues evaluated the safety of Bt rice expressing Cry1Ab protein on health indicators in blood and organs of female Swiss rats. The 30 and 90 day safety studies revealed that Cry1Ab had no significant effect on blood lymph elements such as hemogram, calcium ion concentration, and programmed cell death of lymphocytes. It was also found that Bt rice had no effect on enzyme activities in the organs of Swiss rat. In the 30-day feeding study, changes in the blood biochemistry indexes such as urea, triglyceride (TG), glutamic oxalacetic transaminase (AST) and alkaline phosphatase (ALP) were observed, but not in the 90-day feeding study. This indicates that Cry1Ab protein may influence blood metabolism for a short time.

Further analysis of the 6 genes encoding enzymes involved in the major detoxification functions of liver showed that Bt rice had no effect on the levels of these transcripts in liver of Swiss rat, indicating that significant differences registered in part of the blood biochemical parameters in the 30-day study might result from other untested organs or tissues in response to the stress of exogenous Cry1Ab protein. Based on the findings, it was concluded that Cry1Ab protein has no significant long-term (90 day) effects on female Swiss rat.

Read the research article at http://www.plosone.org/article/info:doi/10.1371/journal.pone.0080424.