Comparative effects of dietary administered transgenic and conventional papaya on selected intestinal parameters in rat models

Transgenic Res. 2010 Jun;19(3):511-8. doi: 10.1007/s11248-009-9317-5. Epub 2009 Aug 19.


Transformation of agricultural crops with novel genes has significantly advanced disease-resistance breeding, including virus resistance through the expression of virus sequences. In this study, the effects of long-term, repeated exposure to transgenic papayas carrying the coat protein gene of Papaya ringspot virus and conventional non-transgenic papaya on the histology and selected biochemical parameters of the intestinal tract were compared. For 3 months, male and female Wistar rats received diets containing transgenic or non-transgenic papaya at twice the equivalent of the average daily consumption of fresh papayas. Gross and macroscopic appearance of intestinal tissues, as well as stomach tissues, was comparable (P < 0.05) as were total intestinal bacterial counts and activities of beta-glucuronidase. Activities of disaccharidases were not affected, neither were those of amylase (P < 0.05). Although significant differences were noted in the activity of Ca(2+) and Na(+)/K(+) ATPase brush border enzymes, no morphological alteration in the integrity of the intestinal mucosa was found. Overall, negligible effects on feed intake, body weight, and fecal output were observed (P < 0.05). Taken together, long-term exposure to diets formulated with transgenic papaya did not result in biologically important unintended effects.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amylases / metabolism
  • Animal Feed / adverse effects
  • Animal Feed / virology*
  • Animals
  • Calcium / metabolism
  • Carica / genetics
  • Carica / virology*
  • Disaccharidases / metabolism
  • Female
  • Gastrointestinal Tract / metabolism*
  • Gastrointestinal Tract / pathology
  • Gastrointestinal Tract / virology
  • Glucuronidase / metabolism
  • Male
  • Microvilli / enzymology
  • Plants, Genetically Modified / genetics
  • Plants, Genetically Modified / virology*
  • Potyvirus*
  • Rats
  • Rats, Wistar
  • Sodium-Potassium-Exchanging ATPase / metabolism


  • Amylases
  • Disaccharidases
  • Glucuronidase
  • Sodium-Potassium-Exchanging ATPase
  • Calcium