Northeastern has a postbac. You can take science courses at bunker hill community college, but that's not ideal. They do offer pre-medical science courses though so I'm threw it out there.
If you're willing to go even further out of Boston, Mount Holyoke has a postbac, so does Framingham State. Probably several others as well. Harvard postbac is a good option. Affordable classes at night that prepare you well for the MCAT.