What I have to do If my active compound showing toxicity in normal cells? - (Dec/28/2014 )

I have assessed anticancer activity of diterpene compound  using A549 cell line as a model. It showed good activity at one concentration. The similar concentration showed same toxic effect in normal cells (L132 cell line) too...Many of my friends telling that a compound with particular concentration should show maximum cytotoxicity in cancer cells but not in normal cells. Almost I have completed many assay using A549 cells, but I just confused with my results what I got in normal cells. What I have to do with this? please anybody clarify my doubt.

I think you might have to precisely titrate the dose in normal vs cancer cells to check the activity/toxicity of the compound you are checking, may be IC50/LD50 would be handy to assess this.

Not all compounds are toxic ONLY to cancer cells, it depends on what you are targeting.