Boswellia sacra essential oil-induced apoptosis in human breast cancer cells. Human breast cancer MDA-MB-231 cells were seeded at the concentration of 5x105 cells/60 mm tissue culture plates for adherence and subjected essential oils (1:800 and 1:1,200 dilutions of 78 and 100 oC, respectively) treatment. Both genomic DNA and total cellular proteins were isolated at specific time points as indicated. (A) Essential oil-induced genomic DNA fragmentation. (B) Essential oil-activated pro- and cleavage of caspases. Experiments were repeated at least twice and representative results are presented.