Repeated Dose 90-Day Feeding Study of Whole Fruits of Genetically Modified Papaya Resistant to Papaya Ringspot Virus in Rats.

Abstract

Genetically modified (GM) papaya plants resistant to infection by Papaya ringspot virus (PRSV) have been successfully generated by cloning the coat protein (CP) gene of PRSV to increase fruit production. In this study, the GM papaya line 823-2210 was used to conduct a 90-day feeding toxicity study and compared to its parent plant of non-GM papaya, Tainung-2 (TN-2) based on the experimental guidance reported by the European Food Safety Authority.1 Ten male and 10 female Sprague-Dawley albino rats were gavaged at low (1 g/kg bw) and high (2 g/kg bw) doses of non-GM and GM lyophilized papaya fruits for 90 days. Hematology, coagulation, biochemistry, urinalysis, and pathology were examined in all animals. Although some differences were found in feed consumption, hematology, and serum chemistry examinations between non-GM and GM papaya, the results were within historical control values and not considered biologically significant in rats. In addition, there were no treatment-related gross or microscopic lesions in male or female rats attributable to the non-GM or GM papaya fruit. This 90-day feeding study of GM papaya fruit did not reveal adverse effects in rats and indicates that GM papaya fruits may be substantially equivalent to their non-GM parent plants.