Frankincense essential oil-induced anti-tumor activity in a xenograft mouse model. Harvested tumors were subjected to formalin fixation and paraffin embedding. Tumor blocks were cut at 5 μm thick, deparaffinized, rehydrated, and stained for cell growth and death markers. (A) Tumor cell growth. Tumor cells that are actively proliferating at the time of harvest were detected by PHH3 immunohistochemical staining. (B) Tumor cell death. Tumor cells undergoing apoptosis at the time of harvest were assessed by TUNEL staining. Images from 2 of each control and frankincense essential oil treated animals are presented (20x magnification); and inserts were taken at 60x magnification to highlight positive immunoreactivity. Immunoreactive cells were counted from a total of 20 randomly selected fields at 40x magnification from 2 separate sections from each animal. Results are presented as total numbers of PHH3- and TUNEL-positive tumor cells from these fields. * and ** indicate statistical differences between untreated and essential oil-treated groups at P < 0.05 and P < 0.01, respectively.
Ni et al. BMC Complementary and Alternative Medicine 2012 12:253 doi:10.1186/1472-6882-12-253