Not natively. You might be able to make it work under an emulator.
Does the Mac even have a serial port, or would an adapter be necessary?
Edit: Some searching of the ChiefDelphi archives yielded
this, which suggests that Virtual PC under OS 10 with a USB to RS-232 adapter can be made to work. Virtual PC is
not free software.
Edit: Reading the original post once more, I'm wondering if you just need a C IDE. Do you plan to actually download code, or merely want to familiarize them with what works in C (but not necessarily on the PIC)?