With Iron Python version 1.1.0

use IronPython.Hosting
use IronPython.Runtime.Types
use IronPython.Runtime.Operations

class Program

    def main
        engine = PythonEngine()
        code = 'print "This is IronPython"'
        engine.execute(code)

Additional information at  http://www.voidspace.org.uk/ironpython/embedding.shtml