How can I help my horses liver recover?

I have a horse and he had to go on stall rest for 2 weeks. so i decided to give him bout 2 ccs of ace for the first time i ride him so he doesnt do anything silly that could jeprodise his recovery. and I have been giving him @ cc's every other day for about 3 weeks and I know that has done some damage on his liver. So I was wondering if there was anything I could do that would help his liver recover. (I do not want to use any grain or supplements)