title: Effects of alpha-santalol on proapoptotic caspases and p53 expression in UVB irradiated mouse skin.
abstract: BACKGROUND
  Cancer chemoprevention by naturally occurring agents, especially phytochemicals, minerals and vitamins has shown promising results against various malignancies in a number of studies both under in vitro and in vivo conditions. One such phytochemical, alpha-santalol, a major component of sandalwood oil, is effective in preventing skin cancer in both chemically and UVB-induced skin cancer development in CD-1, SENCAR and SKH-1 mice; however, the mechanism of its efficacy is not fully understood. The objective of the present investigation was to study the effects of alpha-santalol on apoptosis proteins and p53 in UVB-induced skin tumor development in SKH-1 mice to elucidate the mechanism of action.
  
  
  METHODS
  Female SKH-1 mice were divided into two groups: Group 1, which served as control received topical application of acetone (0.1 ml) one hour before UVB treatment; Group 2 received alpha-santalol (0.1 ml, 5% w/v in acetone, topical) one hour prior to UVB treatment. UVB-induced promotion was continued for 30 weeks.
  
  
  RESULTS
  Pre-treatment with alpha-santalol one hour prior to UVB exposure significantly (p < 0.05) reduced tumor incidence and multiplicity, and resulted in a significant (p < 0.05) increase in apoptosis proteins, caspase-3 and -8 levels and tumor suppressor protein, p53.
  
  
  CONCLUSIONS
  These results suggest that alpha-santalol prevents skin cancer development by inducing proapoptotic proteins via an extrinsic pathway and increasing p53.
authors.affiliation: Department of Pharmaceutical Sciences, South Dakota State University, Brookings, SD 57007, USA.
authors.forename: Bhanu L
authors.initials: BL
authors.lastname: Arasada
authors.forename: Ajay
authors.initials: A
authors.lastname: Bommareddy
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zhang
authors.forename: Kathryn
authors.initials: K
authors.lastname: Bremmon
authors.forename: Chandradhar
authors.initials: C
authors.lastname: Dwivedi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D053148:Caspase 3 / Q000096:biosynthesis; D053181:Caspase 8 / Q000096:biosynthesis; D005260:Female; D051379:Mice; D018632:Mice, Inbred SENCAR; D009381:Neoplasms, Radiation-Induced / Q000209:etiology / Q000517:prevention & control*; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes / Q000494:pharmacology*; D012867:Skin / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects; D012878:Skin Neoplasms / Q000209:etiology / Q000517:prevention & control*; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*; D014466:Ultraviolet Rays
chemical_list: D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes; D016159:Tumor Suppressor Protein p53; C043206:santalol; D053148:Caspase 3; D053181:Caspase 8