Abscisic acid is produced by ALL plants...it has many roles but the one it's probably most "famous" for is abscision of leaves of deciduous plants in the fall. The levels of it fluctuate in the parts of the plant during different developmental periods. I'm guessing you'd have to take mega-doses of it, beyond what you'd be able to get by eating fruits and veggies, in order to see much difference.
I do want to caution you all against trying to ingest anything that's meant to be used on plants. They very likely have things in them that would make them unsafe for human consumption.
Status: Remission since May 2009!
Symptoms began in November 2008, ~4 weeks after giving birth to my son
Diagnosed with pancolitis on 1/30/09
Meds: Apriso (4 0.375g pills ONCE!! daily), mesalamine enema twice weekly, Natural Factors Ultimate probiotic 12/12 Formula, multivitamin. Used prednisone (starting dose 40 mg) to get into remission.