title: Vitamin E reversed nicotine-induced toxic effects on bone biochemical markers in male rats.
abstract: BACKGROUND
  Vitamin E is beneficial in restoring bone histomorphometric parameters in nicotine-treated rats. This study determined the effectiveness of 3 forms of vitamin E in restoring bone metabolism in nicotine-treated rats.
  
  
  METHODS
  Thirty-five male Sprague-Dawley rats were divided into 5 groups: (1) control (C), (2) nicotine cessation (NC), (3) α-tocopherol (ATF), (4) tocotrienol-enhanced fraction (TEF) and (5) γ-tocotrienol (GTT). Treatment was carried out for 4 months. The control group was administered normal saline and olive oil throughout the treatment period while treatment for groups 2-5 was performed in 2 phases. In the first phase, the groups received nicotine 7 mg/kg intraperitoneally for 2 months. The following 2 months, group 2 received normal saline and olive oil while groups 3-5 received ATF, TEF or GTT, 60 mg/kg orally. Pre-treatment and post-treatment serum was collected for bone biochemical marker measurement using the ELISA method.
  
  
  RESULTS
  Nicotine increased serum bone-resorbing cytokines (interleukin-1 and interleukin-6) and the bone resorption marker pyridinoline (PYD) while reducing the bone formation marker osteocalcin after 2 months of nicotine treatment. The parameters failed to improve after nicotine was stopped for 2 months. Supplementation with the 3 forms of vitamin E improved the parameters, i.e. reduced the cytokines and pyridinoline as well as increased the osteocalcin. In addition, the TEF and GTT groups had a higher level of osteocalcin than the control group.
  
  
  CONCLUSIONS
  Nicotine impaired bone metabolism and cessation of nicotine treatment did not reverse the effects. Vitamin E, especially the tocotrienols, restored bone metabolism that was impaired due to nicotine.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Norazlina
authors.forename: Hapidin
authors.initials: H
authors.lastname: Hermizi
authors.forename: Othman
authors.initials: O
authors.lastname: Faizah
authors.forename: Ahmad Shuid
authors.initials: AS
authors.lastname: Nazrun
authors.forename: Muhammad
authors.initials: M
authors.lastname: Norliza
authors.forename: Soelaiman
authors.initials: S
authors.lastname: Ima-Nirwana