Simple Search:

Dose-Dependent Cholesterolemic Activity of Tocotrienols and α-Tocopherol


Citation

Teik, Khor Hun and Theng , Ng Theng and Rajendran, Raajeswari (2002) Dose-Dependent Cholesterolemic Activity of Tocotrienols and α-Tocopherol. Malaysian Journal of Nutrition, 8 (2). pp. 157-166. ISSN 1394-035X

Abstract / Synopsis

Tocotrienols and tocopherols are isoforms of vitamin E. Vitamin E may exhibit antioxidant, prooxidant and non-antioxidant activities depending upon circumstances. In this study, the effect of tocotrienols and α-tocopherol on the activities of HMG CoA reductase and cholesterol 7 α-hydroxylase was investigated. Pure tocotrienols were isolated from palm fatty acid distillate and pure α-tocopherol was obtained commercially. Guinea pigs were treated with different dosages of tocotrienols and α-tocopherol. After the treatment period, animals were sacrificed and liver microsomes were prepared. HMG CoA reductase and cholesterol 7α-hydroxylase were assayed using tracer techniques. Our results showed that the effects of tocotrienols and α-tocopherol on the activities of both the enzymes were dose-dependent. At low dosages, both tocotrienols and α-tocopherol exhibited an inhibitory effect on both the enzymes. Moreover, tocotrienols were a much stronger inhibitors than α-tocopherol. At high dosages, on the other hand, tocotrienols and α-tocopherol showed opposite effects on the enzymes. While tocotrienols continued to exhibit an inhibitory effect, α-tocopherol actually exhibited a stimulatory effect on both the enzymes. A possible explanation for this observation is suggested.


Download File

[img]
Preview
PDF
mjn8n2_art3.pdf - Published Version

Download (440kB)
Official URL: http://nutriweb.org.my

Additional Metadata

Item Type: Article
Divisions: Faculty of Medicine and Health Science
Publisher: Nutrition Society of Malaysia
Depositing User: Mohd Zulkifly Othman
Date Deposited: 08 Jun 2010 15:13
Last Modified: 27 May 2013 15:33
URI: http://psasir.upm.edu.my/id/eprint/7097
Statistic Details: View Download Statistic

Actions (login required)

View Item View Item