Of course concentration is important as everything becomes toxic when you increase the concentration. When doing drug discovery, you are looking for molecules that display the activity you want (here anticancer) at the lowest concentration possible. I'm not expert in anticancer drug discovery, but I would suspect a 26% cell death at 200ug/ml not very interesting in terms of activity... you should check in the literature.

Yes, and if you are looking for some anticancer compounds, the American National Cancer Institute assigns a significant citotoxic effect if it exerts a CC50 value ≤30 ug/mL (Suffness and Pezzuto, 1990). So i recommend you to calculate CC50 values, which give you more idea about your compound´s activity.

I would like to know how many cancer cell lines you have used in your experiment. In our experiments, ≥70% growth inhibition against at least 4 different cancer cell lines (out of the various tested cell lines) at a concentration of 100 μg/mL is considered as a criterion for anticancer activity, SRB assay being used to test cytotoxicity in most cases. Once we get positive result, then we proceed with further testings involving mechanistic studies and more.

Thank You Alok Nahata , It was told only that 26% death is observed for 200ug . Can i say that my molecule have anticancer property?

Hello Byju

According to the National Cancer Institute (NCI), a crude extract can be considered as active if it possesses an IC50 value of less than 20 μg/ml. So Gloria Ivonne Hernández Bolio I too suggest you to calculate IC50. Good luck