some researchers suggests me since your topic toxicity of organs so you do cell line if you go for cell line no need to go for animal study.is it so. please resolve my confusion.
A starting point could be reading a publication about "Toxicity Testing in the 21st Century. A Vision and Strategy" (link is included in this message and please note that it is a "download free PDF." If you want a further look into current and future toxicity testing, PubMed searching will find publications such as one on "Body-on-a-chip systems for animal-free toxicity testing" ((link to the abstract included). Another publication of possible interest is one on "Current limitations and future opportunities for prediction of DILI from in vitro" (link to the abstract included).