Palm tocotrienol-rich fraction inhibits methionine-induced cystathionine β-synthase in rat liver
Abstract Oxidative stress plays an important role in cardiovascular diseases. The study investigated the effects of dietary palm tocotrienol-rich fraction on homocysteine metabolism in rats fed a high-methionine diet. Forty-two male Wistar rats were randomly assigned to six groups. Five groups...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Springer Netherlands
2015
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/44959/ http://irep.iium.edu.my/44959/ http://irep.iium.edu.my/44959/1/paper_CBS_2015.pdf |
| Summary: | Abstract Oxidative stress plays an important role in
cardiovascular diseases. The study investigated the effects
of dietary palm tocotrienol-rich fraction on homocysteine
metabolism in rats fed a high-methionine diet.
Forty-two male Wistar rats were randomly assigned to
six groups. Five groups were fed with high-methionine
diet (1 %) for 10 weeks. Groups 2 to 5 were also given
dietary folate (8 mg/kg) and three doses of palm
tocotrienol-rich fraction (30, 60 and 150 mg/kg) from
week 6 to week 10. The last group was only given basal
rat chow. High-methionine diet increased plasma homocysteine
after 10 weeks, which was prevented by the
supplementations of folate and high-dose palm
tocotrienol-rich fraction. Hepatic S-adenosyl methionine
(SAM) content was unaffected in all groups but
S-adenosyl homocysteine (SAH) content was reduced
in the folate group. Folate supplementation increased
the SAM/SAH ratio, while in the palm tocotrienol-rich
fraction groups, the ratio was lower compared with the
folate. Augmented activity of hepatic cystathionine
β-synthase and lipid peroxidation content by highmethionine
diet was inhibited by palm tocotrienolrich
fraction supplementations (moderate and high
doses), but not by folate. The supplemented groups
had lower hepatic lipid peroxidation than the highmethionine
diet. In conclusion, palm tocotrienolrich
fraction reduced high-methionine-induced hyperhomocysteinaemia
possibly by reducing hepatic
oxidative stress in high-methionine-fed rats. It may
also exert a direct inhibitory effect on hepatic
cystathionine β-synthase.
Keywords Tocotrienol . Methionine . Homocysteine .
S-Adenosyl methionine . S-Adenosyl homocysteine .
Cystathionine β-synthase |
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