Grapefruit seed extract dangers

GSE is often used as a natural antibiotic. I personally have used it internally for sinusitis and GI issues. Mothers give it to their children as a natural alternative. That is why I was very petrified when I stumbled upon some research:

http://www.kantonslabor-bs.ch/content.cfm?nav=46&content=50&Command=details&year=2005&kat=all&ID=86

http://www.kantonslabor-bs.ch/content.cfm?nav=46&content=50&Command=details&year=2004&kat=all&ID=78

http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=182572

I wonder if people use it and if someone has any more info on the dangers suggested in this research.