Hmmm ... good question. I dont have time to read through it now, but this is a pretty good article on it, dont know if it explains the action it takes, but there is a lot of info there none the less.

Milk Thistle

__________________
I don't do this for my family, my friends, women, accolades, pride, or ego. I do it for me and no one else, its just part of who I am.