In this paper, they first dissolved genistein in DMSO, then with water, so that the final solution was "only" 10% DMSO for oral gavage in Balb/c mice : Article Absolute Bioavailability of Isoflavones from Soy Protein Iso...
I think it's fine to do that for an acute administration. If you plan to give this chronically, you may want to try other solvents that are less toxic, or dilute even more the DMSO.
For instance, you can first dissolve your compound in ethanol and further dilute it with vegetable oil. This is usually well tolerated by oral gavage.