Your question is not clear, what is the aim of your study, to demonstrate that DMSO protects the liver from hepatotoxicity of CCl4? Or do you wish to avoid using a vehicle (DMSO) that may provide protection against hepatotoxicity and thereby confound the results of your study? It is not possible to answer your question without more information. However, if you do use DMSO for any studies please make sure that it is a fresh stock and has been stored correctly. Over time, DMSO can oxidize and can generate some toxic and genotoxic degradation products.
Dmso is not advised as vehicle as it causes oxidatedamage to cells and it further potentiates the hepatic toxicity it will interfere in u r results. normally the plant extracts are administered as gum acacia/tragacanth ; emulsions/suspensions. if the design of the study approve with the use of ccl4 u can use peanut oil as vehicle.