Some watermelon could have same effect as Viagra: ; Big red slice, or little blue pill?

LUBBOCK, Texas - A slice of cool, fresh watermelon is a juicy wayto top off a Fourth of July cookout and one that researchers say haseffects similar to Viagra - but don't necessarily expect it to keepthe fireworks all night long.

Watermelons contain an ingredient called citrulline that cantrigger production of a compound that helps relax the body's bloodvessels, similar to what happens when a man takes Viagra, saidscientists in Texas, one of the nation's top producers of theseedless variety.

Found in the flesh and rind of watermelons, citrulline reactswith the body's enzymes when consumed in large quantities and ischanged into arginine, an amino acid that benefits …