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Evidence-Based Complementary and Alternative Medicine
Volume 2012, Article ID 680834, 10 pages
http://dx.doi.org/10.1155/2012/680834
Research Article

Effects of Low-Dose versus High-Dose γ-Tocotrienol on the Bone Cells Exposed to the Hydrogen Peroxide-Induced Oxidative Stress and Apoptosis

1Department of Pharmacology, Faculty of Medicine, National University of Malaysia (UKM), Kuala Lumpur Campus, Raja Muda Abdul Aziz Road, 50300 Kuala Lumpur, Malaysia
2Department of Human Anatomy, Faculty of Medicine and Health Sciences, Putra University of Malaysia (UPM), 43400 UPM Serdang, Selangor, Malaysia

Received 3 June 2012; Accepted 24 July 2012

Academic Editor: Ima Nirwana Soelaiman

Copyright © 2012 Nizar Abd Manan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Oxidative stress and apoptosis can disrupt the bone formation activity of osteoblasts which can lead to osteoporosis. This study was conducted to investigate the effects of γ-tocotrienol on lipid peroxidation, antioxidant enzymes activities, and apoptosis of osteoblast exposed to hydrogen peroxide (H2O2). Osteoblasts were treated with 1, 10, and 100 μM of γ-tocotrienol for 24 hours before being exposed to 490 μM (IC50) H2O2 for 2 hours. Results showed that γ-tocotrienol prevented the malondialdehyde (MDA) elevation induced by H2O2 in a dose-dependent manner. As for the antioxidant enzymes assays, all doses of γ-tocotrienol were able to prevent the reduction in SOD and CAT activities, but only the dose of 1 μM of GTT was able to prevent the reduction in GPx. As for the apoptosis assays, γ-tocotrienol was able to reduce apoptosis at the dose of 1 and 10 μM. However, the dose of 100 μM of γ-tocotrienol induced an even higher apoptosis than H2O2. In conclusion, low doses of γ-tocotrienol offered protection for osteoblasts against H2O2 toxicity, but itself caused toxicity at the high doses.