BUKU ABSTRAK - Universiti Putra Malaysia

Effect of Hypocholesterolemic Properties of Brown Rice Varieties Containing Different
Gamma Aminobutyric Acid (GABA) Levels on Sprague-Dawley Male Rats
Prof. Dr. Mohd. Yazid Abd. Manap
Shahin Roohinejad, Leila Nateghi, Alireza Omidizadeh, Hamed Mirhosseini, Babak Rasti, Nazamid Saari,
Shuhaimi Mustafa, Rokiah Mohd. Yusof, Anis Shobirin Meor Hussin and Azizah Hamid
Faculty of Food Science and Technology, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 8367; myazid@putra.upm.edu.my
Brown rice (BR) or unmilled rice is the whole grain of rice, from which the germ and outer layers containing
the bran have not been removed. Brown rice seeds are rich in more nutritional components, such as dietary
fibers, vitamins B and E, gamma (?)-oryzanol and ?-amino butyric acid (GABA) than the ordinary milled
rice grains. GABA or 4-aminobutyrate is a well known non-protein-based amino acid that is one of the major
inhibitory neurotransmitters in the sympathetic nervous system. In the present study, the influence of brown rice
varieties containing different GABA levels on blood cholesterol in Sprague-Dawley male rats was investigated.
Quantitative analysis of GABA, Gamma oryzanol, dietary fiber, protein and fat was carried out using appropriate
method. Hypercholesterolemia and elevation of LDL-cholesterol were successfully ameliorated by most of the
brown rice diets (p < 0.05). A significant negative correlation (p < 0.05) between serum TC level and ?-oryzanol
content of diets was observed. Moreover, a significant negative correlation (p < 0.05) between serum LDL-C level
and dietary fiber content of diets was observed. In contrast, there was no correlation between GABA content and
TC, LDL-C, HDL-C and glucose levels. Although no correlation was found between GABA content and lipid
profile suppression, this study suggests that the changes of blood cholesterol can be modulated by using brown
rice varieties instead of polished rice in human diet. Even though GABA does not play a role for prediction of
lipid profile changes, this study is capable of showing the hypercholesterolemic effect of brown rice varietiess.
Keywords: Brown rice, ?-oryzanol, dietary fiber, ?-amino butyric acid (GABA), hypercholesterolemia, functional food,
protein, fat, Sprague-Dawley, male rat
Effect of Pre-germination Time of Brown Rice on Serum Cholesterol Levels of
Hypercholesterolaemic Rats
Prof. Dr. Mohd. Yazid Abd. Manap
Shahin Roohinejad, Leila Nateghi, Alireza Omidizadeh, Hamed Mirhosseini, Nazamid Saari, Shuhaimi Mustafa,
Rokiah Mohd Yusof, Anis Shobirin Meor Hussin and Azizah Hamid
Faculty of Food Science and Technology, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 8367; myazid@putra.upm.edu.my
Brown rice is unpolished rice with immeasurable benefits for human health. Brown rice (BR) and pregerminated
brown rice (PGBR) are known to contain various functional compounds such as ? -oryzanol, dietary
fibre and ?-aminobutyric acid (GABA). In the present study, the experimental diets containing BR and PGBR
(24, 48 hours of pre-germination) were used to investigate the influence of pre-germination time of brown rice
on blood cholesterol in Sprague-Dawleymale rats. Hypercholesterolaemia and elevation of LDL-cholesterol
were successfully ameliorated by the experimental diets containing BR and PGBR (24 and 48 hours of pregermination).
As compared to the control sample, the pre-germination time had a significant (P < 0.05) effect
on blood cholesterol of Sprague-Dawley male rats. It was also found that the significantly (P < 0.05) better
effect on lipid profile of hypercholesterolaemic rats was observed by prolonging the pre-germination time. As
compared to non-germinated brown rice, the germinated brown rice showed higher cardio-protective effect on
hypercholesterolaemic Sprague-Dawley male rats. The present study suggests that the changes of blood cholesterol
can be mainly modulated by using the PGBR rather than BR. The prolonging of pre-germination time led to an
increase in the bioactive components, thereby providing a more efficient functional diet affecting the high blood
cholesterol. This study suggests that PGBR can be used instead of BR and polished rice in the human diet.
Keywords: Brown rice, pre-germination, ? -oryzanol; dietary fibre, ? -amino butyric acid (GABA), hypercholesterolaemia
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Food