There's a heap that will do that (jasplakinolide, cytochalasins, swinholides etc.) but how useful they will be really depends on your application. The issue with targeting either of those things, especially in vivo, is the lack of specificity. Inhibiting it to any appreciable degree in your organ of interest will also inhibit it in the heart and other vital organs and the animal dies shortly after.

Anything that directly interferes with actin homeostasis also causes severe systemic toxicity so your best bet would be to look for drugs targeting myosin. Depending on the application, you may be able to use blebbistatin though. It's specific for myosin II.