Suppression of pancreatic cancer cell viability in response to frankincense essential oil treatment. Human pancreatic cancer cells (5 × 103 in 100 μl) were seeded in each well of 96-well tissue culture plates for adherence. Cells were subjected to serial dilutions of frankincense essential oils treatment, (A) Fraction I obtained at 78°C hydrodistillation for 0–2 h, (B) Fraction II obtained at 78°C for 8–10 h. (C) Fraction III obtained at 78°C for 11–12 h, or (D) Fraction IV obtained at 100°C for 11–12 h. All experiments were prepared in triplicate. Cell viability was determined at 24 h following essential oil treatment using the XTT colorimetric assay. Results are presented as mean cell viability (%) ± standard error of mean (SEM) in relation to the number of cells at the time of essential oil treatment from at least 4 independent experiments. * indicates statistical difference in cell viability between essential oil-treated and untreated cells (P < 0.05).