Effect of dietary supplementation of tocotrienols and tocopherols on serum lipids in the hamster

Abstract

Male Syrian Golden hamsters were fed on semi-synthetic diets containing palm olein triglycerides (POTG) as the source of dietary lipid. The POTG isolated from commercial palm olein were supplemented with 72 ppm of tocopherols (T) or 162 or 1000 ppm of tocotrienols (T3) isolated from palm fatty acid distillate for 45 days. The animals grew well and healthy. There were no significant difference in body weight gains. At the end of the experiments, the hamsters were fasted overnight and blood was taken by cardiac puncture. Serum was prepared by centrifugation at room temperature. Blood lipids were assayed by Sigma enzyme kits and serum vitamin E levels were analyzed by normal phase HPLC with a fluorescent detector. Our results show that supplementation of POTG with 72 ppm of tocopherols (POTG-T) raised the serum TC, LDL-C, HDL-C levels and lowered the serum TG level as compared to that of the POTG but the differences were not statistically significant. Supplementation of POTG with 162 ppm of tocotrienols (POTG-T3L) lowered the serum TC level significantly (P<0.05), but it did not significantly lower the LDL-C, HDL-C and serum TG levels as compared with the POTG group. Supplementation of POTG with higher amounts of tocotrienols i.e. 1000 ppm did not result in further reduction in serum TC, LDL-C, HDL-C and TG levels as compared to the POTG-T3L group; on the contrary, the POTG-T3H group raised LDL-C level significantly when compared to the POTG-T3L group. Analysis of the serum and liver vitamin E levels show that α-T was the main vitamin E in the serum and liver irrespective of whether tocopherols or tocotrienols were supplemented to the oils. Small amounts of tocotrienols appeared in the serum and liver only when tocotrienols were supplemented at high level, 1000 ppm. These results indicate that tocotrienols possess hypo-cholesterolemic effect and tocopherols may have slight hypercholesterolemic effect in the hamster. Supplementation with high level of tocotrienols did not increase the hypo-cholesterolemic effect of the tocotrienols.