EFFECT OF SQUALENE, TOCOTRIENOLS AND ALPHA-TOCOPHEROL SUPPLEMENTATIONS IN THE DIET ON SERUM AND LIVER LIPIDS IN THE HAMSTER

The short-term effect of dietary squalene (SQ) tocotrienols (T3) and a lpha-tocopherol (T) on serum and liver cholesterol levels was investig ated in the hamster. Our results show that dietary squalene (0.1%) low ered serum total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) levels as co mpared with the control palm oil triacylglycerol (POTG) group; however , only the difference between serum TC levels of the two groups was si gnificant (P<0.05). In the presence of 162 ppm of tocotrienols or 72 p pm of alpha-tocopherol the serum TC and LDL-C levels of squalene-fed h amsters were further lowered (P<0.01) as compared with that of the POT G and POTG-SQ groups; the HDL-C level appeared unaffected. As for the serum TAG level, the effect of squalene, tocotrienols and alpha-tocoph erol were inconsistent. The liver total lipids of the squalene-fed (PO TG-SQ), squalene and T3-fed (POTG-SQ-T3) and squalene and alpha-tocoph erol-fed (POTG-SQ-T) hamsters were significantly increased as compared to that of the POTG group. This increase in total lipids was due to s ignificant increases in TC and Cholesterol ester (CE) levels in the li ver of the treated groups as compared with the control group (POTG). L iver TAG level was not affected consistently in treated groups. Our re sults show that short-term low-level (0.1%) squalene feeding lowered s erum cholesterol levels by increasing cholesterol ester accumulation i n the liver. Tocotrienols and alpha-tocopherol enhanced the serum chol esterol-lowering effect of dietary squalene without increasing further the cholesterol ester accumulation activity in the liver of the hamst er. Copyright (C) 1997 Elsevier Science Inc.