METHODS: Thirty-five male rabbits of New Zealand strain were randomly assigned to seven groups. For 12 weeks, group CH was fed 1% cholesterol diet only; group C1 was fed 1% cholesterol diet and 0.50 ml/kg/day B. angulata WF juice; group C2 was fed 1% cholesterol diet and 1.00 ml/kg/day B. angulata WF juice; group C3 was fed 1% cholesterol diet and 1.50 ml/kg/day B. angulata WF juice; group N was fed standard pellet only; group N1 was fed standard pellet and 0.50 ml/kg/day B. angulata WF juice; and group N2 was fed standard pellet and 1.00 ml/kg/day B. angulata WF juice.
RESULTS: The three doses reduced the formation of MDA and enhanced the expression of endogenous antioxidant enzymes. The highest dose used (1.50 ml/kg/day) was, however, seen as the most potent.
CONCLUSION: Higher doses of B. angulata juice exerted better antioxidant activity.
OBJECTIVE: The primary study objective was to evaluate the postprandial fate of tocotrienols and alpha-tocopherol in human plasma and lipoproteins.
DESIGN: Seven healthy volunteers (4 males, 3 females) were administered a single dose of vitamin E [1011 mg palm tocotrienol-rich fraction (TRF) or 1074 mg alpha-tocopherol] after a 7-d conditioning period with a tocotrienol-free diet. Blood was sampled at baseline (fasted) and 2, 4, 5, 6, 8, and 24 h after supplementation. Concentrations of tocopherol and tocotrienol isomers in plasma, triacylglycerol-rich particles (TRPs), LDLs, and HDLs were measured at each interval.
RESULTS: After intervention with TRF, plasma tocotrienols peaked at 4 h (4.79 +/- 1.2 microg/mL), whereas alpha-tocopherol peaked at 6 h (13.46 +/- 1.68 microg/mL). Although tocotrienols were similarly detected in TRPs, LDLs, and HDLs, tocotrienol concentrations were significantly lower than alpha-tocopherol concentrations. In comparison, plasma alpha-tocopherol peaked at 8 h (24.3 +/- 5.22 microg/mL) during the alpha-tocopherol treatment and emerged as the major vitamin E isomer detected in plasma and lipoproteins during both the TRF and the alpha-tocopherol treatments.
CONCLUSIONS: Tocotrienols are detected in postprandial plasma, albeit in significantly lower concentrations than is alpha-tocopherol. This finding confirms previous observations that, in the fasted state, tocotrienols are not detected in plasma. Tocotrienol transport in lipoproteins appears to follow complex biochemically mediated pathways within the lipoprotein cascade.