squalene, and octacosanol present in RBO has the ability to reduce total blood
plasma cholesterol and triglycerides while raising HDL cholesterol which in turn
helps to improve the plasma lipid profile (Cicero and Gaddi 2001; Wang et al. 2003;
Wilson et al. 2007). In a study, various unsaturated vegetable oils were evaluated for
their effect on serum lipoprotein levels in monkeys. The remarkable decrease of 25%
and 30%, respectively, in total serum cholesterol and LDL cholesterol was found in
the animals fed with a diet containing RBO (Wilson et al. 2000). In another study,
the hypocholesterolemic effect of refined RBO along with coconut oil and canola oil
was evaluated in hamsters. The animals were fed on a chow-based diet in addition to
0.03% cholesterol along with 5% oils (w/w) for 8 weeks. A significant reduction
(P < 0.05) in cholesterol absorption (15–17% reduction), plasma TC and LDL-C
(42% and 48%, respectively) was observed in RBO-treated animal groups (Ausman
et al. 2005).
The hypolipidemic effect was evaluated for γ-oryzanol fraction of RBO blended
with refined groundnut oil gum (3–10%). The result showed a 15% decrease in the
cholesterol level in the liver and 7–16% decrease in blood serum cholesterol
compared to a diet containing pure groundnut oil (Chandrashekar et al. 2012). To
evaluate the antihyperlipidemic effect, the phytochemical γ-oryzanol at different
concentrations ranging from 50 and 100 mg/kg was fed to the hyperlipidemic rats for
21 days/3 weeks. Regardless of the dose administered, significant decrease
(P < 0.05) in the levels of serum cholesterol, triacylglycerides, LDL, VLDL and a
significant increase in the level of serum HDL and hepatic antioxidant enzymes were
found in the groups treated with the γ-oryzanol compared to control group that was
fed on atorvastatin (a pharmaceutical agent administered to lower blood cholesterol)
(Ghatak and Panchal 2012). Wilson et al. (2007) evaluated the cholesterol-lowering
properties of γ-Oryzanol, trans-ferulic acid, and RBO in hamsters for 10 weeks. In
comparison to the control group (hamsters fed on chow-based hypercholesterolemic
diet (HCD) containing 10% coconut oil and 0.1% cholesterol), the total plasma
cholesterol, LDL and VLDL were significantly (P < 0.05) lower in animals fed with
γ-oryzanol (0.5%) followed by RBO (10% RBO in place of coconut oil) and transferulic acid (0.5%). Similarly, lipid profile had also been improved using other
bioactive components extracted from rice bran oil. Lipid levels were evaluated in
rats using regular diet, high cholesterol diet, and diet containing RBO concentrated
mixture (composition of the concentrated mixture was 277.7 γ-oryzanol, 89.99
phytosterols, 11.66 tools, 3.36 squalene, and 0.73 octacosanols). Rats fed with a
diet containing RBO concentrated mix (15gm/kg diet) revealed significantly
(P < 0.05) upsurge in HDL level compared with high cholesterol diet. HDL lowers
the risk of arteriosclerosis by minimizing the cholesterol deposition in the endothelium and carrying it to the liver for excretion (Ha et al. 2005).
Vitamin E, tocopherols and tocotrienols are synthesized in the plants and are
proven antioxidants and exert hypolipidemic effects (Xu et al. 2001). However,
prolonged intake of vitamin E and dose higher than RDA could have a pro-oxidant
effect (Pearson et al. 2006). In an experimental study, RBO extracted tocotrienolrich fraction (TRF) was investigated for 1 week in hyperlipidemic rats at a concentration of 0–50 mg TRF/kg/day. TRF-treated rats showed a dose-dependent 38–48%
16 Rice (Oryza sativa) Bran
403
plasma cholesterol and triglycerides while raising HDL cholesterol which in turn
helps to improve the plasma lipid profile (Cicero and Gaddi 2001; Wang et al. 2003;
Wilson et al. 2007). In a study, various unsaturated vegetable oils were evaluated for
their effect on serum lipoprotein levels in monkeys. The remarkable decrease of 25%
and 30%, respectively, in total serum cholesterol and LDL cholesterol was found in
the animals fed with a diet containing RBO (Wilson et al. 2000). In another study,
the hypocholesterolemic effect of refined RBO along with coconut oil and canola oil
was evaluated in hamsters. The animals were fed on a chow-based diet in addition to
0.03% cholesterol along with 5% oils (w/w) for 8 weeks. A significant reduction
(P < 0.05) in cholesterol absorption (15–17% reduction), plasma TC and LDL-C
(42% and 48%, respectively) was observed in RBO-treated animal groups (Ausman
et al. 2005).
The hypolipidemic effect was evaluated for γ-oryzanol fraction of RBO blended
with refined groundnut oil gum (3–10%). The result showed a 15% decrease in the
cholesterol level in the liver and 7–16% decrease in blood serum cholesterol
compared to a diet containing pure groundnut oil (Chandrashekar et al. 2012). To
evaluate the antihyperlipidemic effect, the phytochemical γ-oryzanol at different
concentrations ranging from 50 and 100 mg/kg was fed to the hyperlipidemic rats for
21 days/3 weeks. Regardless of the dose administered, significant decrease
(P < 0.05) in the levels of serum cholesterol, triacylglycerides, LDL, VLDL and a
significant increase in the level of serum HDL and hepatic antioxidant enzymes were
found in the groups treated with the γ-oryzanol compared to control group that was
fed on atorvastatin (a pharmaceutical agent administered to lower blood cholesterol)
(Ghatak and Panchal 2012). Wilson et al. (2007) evaluated the cholesterol-lowering
properties of γ-Oryzanol, trans-ferulic acid, and RBO in hamsters for 10 weeks. In
comparison to the control group (hamsters fed on chow-based hypercholesterolemic
diet (HCD) containing 10% coconut oil and 0.1% cholesterol), the total plasma
cholesterol, LDL and VLDL were significantly (P < 0.05) lower in animals fed with
γ-oryzanol (0.5%) followed by RBO (10% RBO in place of coconut oil) and transferulic acid (0.5%). Similarly, lipid profile had also been improved using other
bioactive components extracted from rice bran oil. Lipid levels were evaluated in
rats using regular diet, high cholesterol diet, and diet containing RBO concentrated
mixture (composition of the concentrated mixture was 277.7 γ-oryzanol, 89.99
phytosterols, 11.66 tools, 3.36 squalene, and 0.73 octacosanols). Rats fed with a
diet containing RBO concentrated mix (15gm/kg diet) revealed significantly
(P < 0.05) upsurge in HDL level compared with high cholesterol diet. HDL lowers
the risk of arteriosclerosis by minimizing the cholesterol deposition in the endothelium and carrying it to the liver for excretion (Ha et al. 2005).
Vitamin E, tocopherols and tocotrienols are synthesized in the plants and are
proven antioxidants and exert hypolipidemic effects (Xu et al. 2001). However,
prolonged intake of vitamin E and dose higher than RDA could have a pro-oxidant
effect (Pearson et al. 2006). In an experimental study, RBO extracted tocotrienolrich fraction (TRF) was investigated for 1 week in hyperlipidemic rats at a concentration of 0–50 mg TRF/kg/day. TRF-treated rats showed a dose-dependent 38–48%
16 Rice (Oryza sativa) Bran
403