title: Differential effects of selective frankincense (Ru Xiang) essential oil versus non-selective sandalwood (Tan Xiang) essential oil on cultured bladder cancer cells: a microarray and bioinformatics study.
abstract: BACKGROUND
  Frankincense (Boswellia carterii, known as Ru Xiang in Chinese) and sandalwood (Santalum album, known as Tan Xiang in Chinese) are cancer preventive and therapeutic agents in Chinese medicine. Their biologically active ingredients are usually extracted from frankincense by hydrodistillation and sandalwood by distillation. This study aims to investigate the anti-proliferative and pro-apoptotic activities of frankincense and sandalwood essential oils in cultured human bladder cancer cells.
  
  
  METHODS
  The effects of frankincense (1,400-600 dilutions) (v/v) and sandalwood (16,000-7,000 dilutions) (v/v) essential oils on cell viability were studied in established human bladder cancer J82 cells and immortalized normal human bladder urothelial UROtsa cells using a colorimetric XTT cell viability assay. Genes that responded to essential oil treatments in human bladder cancer J82 cells were identified using the Illumina Expression BeadChip platform and analyzed for enriched functions and pathways. The chemical compositions of the essential oils were determined by gas chromatography-mass spectrometry.
  
  
  RESULTS
  Human bladder cancer J82 cells were more sensitive to the pro-apoptotic effects of frankincense essential oil than the immortalized normal bladder UROtsa cells. In contrast, sandalwood essential oil exhibited a similar potency in suppressing the viability of both J82 and UROtsa cells. Although frankincense and sandalwood essential oils activated common pathways such as inflammatory interleukins (IL-6 signaling), each essential oil had a unique molecular action on the bladder cancer cells. Heat shock proteins and histone core proteins were activated by frankincense essential oil, whereas negative regulation of protein kinase activity and G protein-coupled receptors were activated by sandalwood essential oil treatment.
  
  
  CONCLUSIONS
  The effects of frankincense and sandalwood essential oils on J82 cells and UROtsa cells involved different mechanisms leading to cancer cell death. While frankincense essential oil elicited selective cancer cell death via NRF-2-mediated oxidative stress, sandalwood essential oil induced non-selective cell death via DNA damage and cell cycle arrest.
authors.affiliation: Arthritis & Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
authors.forename: Mikhail G
authors.initials: MG
authors.lastname: Dozmorov
authors.affiliation: Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA ; Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
authors.forename: Weijuan
authors.initials: W
authors.lastname: Wu
authors.affiliation: Arthritis & Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Wren
authors.affiliation: Dhofar Frankincense Research Plant, Salalah AYUBS42, Sultanate of Oman.
authors.forename: Mahmoud M
authors.initials: MM
authors.lastname: Suhail
authors.affiliation: Young Living Essential Oils, Lehi, UT 84043, USA.
authors.forename: Cole L
authors.initials: CL
authors.lastname: Woolley
authors.affiliation: Young Living Essential Oils, Lehi, UT 84043, USA.
authors.forename: D Gary
authors.initials: DG
authors.lastname: Young
authors.affiliation: Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA ; Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA ; Oklahoma City Veterans Medical Center, Oklahoma City, OK 73104, USA.
authors.forename: Kar-Ming
authors.initials: KM
authors.lastname: Fung
authors.affiliation: Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA ; Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA ; Department of Urology, University of Oklahoma Medical Center, 920 Stanton L. Young Blvd., WP 3150, Oklahoma City, OK 73034, USA.
authors.forename: Hsueh-Kung
authors.initials: HK
authors.lastname: Lin