Monthly Archives: April 1991

Lowering of serum cholesterol in hypercholesterolemic humans by tocotrienols (palmvitee)

Qureshi AA, Qureshi N, Wright JJ, Shen Z, Kramer G, Gapor A, Chong YH, DeWitt G, Ong A, Peterson DM, et al.

Am J Clin Nutr. 1991 Apr;53(4 Suppl):1021S-1026S.

Abstract

A double-blind, crossover, 8-wk study was conducted to compare effects of the tocotrienol-enriched fraction of palm oil (200 mg palmvitee capsules/day) with those of 300 mg corn oil/d on serum lipids of hypercholesterolemic human subjects (serum cholesterol 6.21-8.02 mmol/L). Concentrations of serum total cholesterol (-15%), LDL cholesterol (-8%), Apo B (-10%), thromboxane (-25%), platelet factor 4 (-16%), and glucose (-12%) decreased significantly only in the 15 subjects given palmvitee during the initial 4 wk. The crossover confirmed these actions of palmvitee. There was a carry over effect of palmvitee. Serum cholesterol concentrations of seven hypercholesterolemic subjects (greater than 7.84 mmol/L) decreased 31% during a 4-wk period in which they were given 200 mg gamma-tocotrienol/d. This indicates that gamma-tocotrienol may be the most potent cholesterol inhibitor in palmvitee capsules. The results of this pilot study are very encouraging.

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Dietary tocotrienols reduce concentrations of plasma cholesterol, apolipoprotein B, thromboxane B2, and platelet factor 4 in pigs with inherited hyperlipidemias

Qureshi AA, Qureshi N, Hasler-Rapacz JO, Weber FE, Chaudhary V, Crenshaw TD, Gapor A, Ong AS, Chong YH, Peterson D, et al.

Am J Clin Nutr. 1991 Apr;53(4 Suppl):1042S-1046S.

Normolipemic and genetically hypercholesterolemic pigs of defined lipoprotein genotype were fed a standard diet supplemented with 50 micrograms/gtocotrienol-rich fraction (TRF) isolated from palm oil. Hypercholesterolemic pigs fed the TRF supplement showed a 44% decrease in total serum cholesterol, a 60% decrease in low-density-lipoprotein (LDL)-cholesterol, and significant decreases in levels of apolipoprotein B (26%), thromboxane-B2 (41%), and platelet factor 4 (PF4; 29%). The declines in thromboxane B2 and PF4 suggest that TRF has a marked protective effect on the endothelium and platelet aggregation. The effect of the lipid-lowering diet persisted only in the hypercholesterolemic swine after 8 wk feeding of the control diet. These results support observations from previous studies on lowering plasma cholesterol in animals by tocotrienols, which are naturally occurring compounds in grain and palm oils and may have some effect on lowering plasma cholesterol in humans.

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The bioactivities of RRR-alpha-, beta-, gamma-, and delta-tocopherol (T) and R-alpha-tocotrienol (R-alpha-TT) were determined in rat resorption-gestation tests. The ranking order was RRR-alpha-T greater than RRR-beta-T greater than RRR-gamma-T greater than or equal to R-alpha-TT greater than RRE-delta-T. Accordingly, the biopotency of a palm-oil residue was assessed and expressed as alpha-tocopherol equivalents (alpha-TEs). The release of pyruvate kinase, a variable in the nutrition-linked necrotizing myopathy, into the plasma was dose-dependently inhibited by the RRR-alpha-T standard and the corresponding alpha-TE from this residue. Prostacyclin synthesis from aorta segments induced by thrombin or ionomycin was higher than the spontaneous release. However, there was no difference between the depleted group and groups treated with RRR-alpha-T or alpha-TEs from the palm-oil residue. Quantities of IgG in plasma of vitamin E-depleted rats were the highest. Upon supplementation with RRR-alpha-T or alpha-TEs from the palm-oil residue, reduced IgG concentrations were observed, similar to those of animals on a commercial diet containing adequate amounts of vitamin E.

Effect of a Palm-Oil Vitamin E Concentrate on the Serum and Lipoprotein Lipids in Humans

Tan DT, Khor HT, Low WH, Ali A, Gapor A.

Am J Clin Nutr. 1991 Apr;53(4 Suppl):1027S-1030S.

Published

Objectives: To assess the effect of a capsulated palm-oil-vitamin E concentrate (Palmvitee) on human serum and lipoprotein lipids.

Subjects: Healthy volunteers

Intervention: Palm-oil vitamin E concentrate (18 mg tocotrienol)

Primary outcome: Serum lipids and lipoproteins

Methodology: All volunteers took one palmvitee capsule per day for 30 consecutive days. Overnight fasting blood was taken from each volunteer before and after the experiment. Serum lipids and lipoproteins were analyzed by using the enzymatic CHOD-PAP method.

Results: Our results showed that palmvitee lowered both serum total cholesterol (TC) and low-density-lipoprotein cholesterol (LDL-C) concentrations in all the volunteers. The magnitude of reduction of serum TC ranged from 5.0% to 35.9% whereas the reduction of LDL-C values ranged from 0.9% to 37.0% when compared with their respective starting values. Theeffect of palmvitee on triglycerides (TGs) and HDL-C was not consistent.

Conclusion: The results show that the palmvitee has a hypocholesterolemic effect.

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Lowering of serum cholesterol in hypercholesterolemic humans by tocotrienols (Palmvitee)

Qureshi AA, Qureshi N, Wright JJ, Shen Z, Kramer G, Gapor A, Chong YH, DeWitt G, Ong A, Peterson DM, et al.

Am J Clin Nutr. 1991 Apr;53(4 Suppl):1021S-1026S.

Published

Objectives: The present study was carried out to assess the effect of tocotrienol-rich fraction as a dietary supplement in hypercholesterolemic human subjects.

Study design: Double-blind, crossover, 8 week study

Subjects: Subjects with elevated cholesterol levels

Intervention: Tocotrienol-rich fraction (Palmvitee) 200 mg versus placebo (300 mg corn oil capsules)

Primary outcome: To determine the cholesterol lowering effect of palmvitee

Methodology: A double-blind, crossover experimental design was used to control within-subject variability of cholesterol measurements and the effect of order of the administration of the two supplements (palmvitec and corn oil for a placebo). Subjects were radomly assigned to one of two groups. In group I, each subject was observed for 2-wk baseline period, a 4-wk palmvitee-capsule supplementation period, and a 4-wk corn-oil-capsule supplementation period. In group II, each subject was observed for a 2 wk baseline period, a 4-wk corn-oil-capsule supplementation period, and a 4-6-wk palmvitee supplementation period.

Results: Concentrations of serum total cholesterol (-15%), LDL cholesterol (-8%), Apo B (-10%), thromboxane (-25%), platelet factor 4 (-16%), and glucose (-12%) decreased significantly only in the 15 subjects given palmvitee during the initial 4 wk. The crossover confirmed these actions of palmvitee. There was a carry over effect of palmvitee. Serum cholesterol concentrations of seven hypercholesterolemic subjects (greater than 7.84 mmol/L) decreased 31% during a 4-wk period in which they were given 200 mg gamma-tocotrienol/d.

Conclusion: This indicates that gamma-tocotrienol may be the most potent cholesterol inhibitor in palmvitee capsules. The results of this pilot study are very encouraging.

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Effect of tocotrienols on hepatocarcinogenesis induced by 2-acetylaminofluorene in rats

Ngah WZ, Jarien Z, San MM, Marzuki A, Top GM, Shamaan NA, Kadir KA.

Am J Clin Nutr. 1991 Apr;53(4 Suppl):1076S-1081S.

The effects of tocotrienols on hepatocarcinogenesis in rats fed with 2-acetylaminofluorene (AAF) were followed morphologically and histologically for a period of 20 wk. No differences between treated and control rats in the morphology and histology of their livers was observed. Cell damage was extensive in the livers of AAF-treated rats but less extensive in the AAF-tocotrienols-treated rats when compared with normal and tocotrienols-treated rats. 2-Acetylaminofluorene significantly increases the activities of both plasma and liver microsomal gamma-glutamyltranspeptidase (GGT) and liver microsomal UDP-glucuronyltransferase (UDP-GT). Tocotrienols administered together with AAF significantly decrease the activities of plasma GGT after 12 and 20 wk (P less than 0.01, P less than 0.002, respectively) and liver microsomal UDP-GT after 20 wk (P less than 0.02) when compared with the controls and with rats treated only with tocotrienols. Liver microsomal GGT also showed a similar pattern to liver microsomal UDP-GT but the decrease was not significant. These results suggest that tocotrienols administered to AAF-treated rats reduce the severity of hepatocarcinogenesis.

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A comparison of tocopherol and tocotrienol for the chemoprevention of chemically induced rat mammary tumors

Gould MN, Haag JD, Kennan WS, Tanner MA, Elson CE.

Am J Clin Nutr. 1991 Apr;53(4 Suppl):1068S-1070S.

Two forms of vitamin E, tocopherol and tocotrienol, were tested for chemopreventive activity in two chemically induced rat mammary-tumor models. When mammary tumors were induced by 7,12-dimethylbenz(a)anthracene (DMBA, 50 mg/kg), only the tocotrienol group had a statistically significant increase in tumor latency. There was no effect of either compound on tumor multiplicity. When tumors were induced by N-nitrosomethylurea (NMU, 30 mg/kg), neither analogue of vitamin E modified latency, whereas tocotrienol increased tumor multiplicity. In summary, neither vitamin analog had a major impact on mammary-tumor development after tumor induction with either DMBA or NMU.

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Effect of a Palm-Oil Vitamin E Concentrate on the Serum and Lipoprotein Lipids in Humans

Tan DT, Khor HT, Low WH, Ali A, Gapor A.

Am J Clin Nutr. 1991 Apr;53(4 Suppl):1027S-1030S.

The effect of a capsulated palm-oil-vitamin E concentrate (palmvitee) on human serum and lipoprotein lipids was assessed. Each palmvitee capsule contains approximately 18, approximately 42, and approximately 240 mg of tocopherols, tocotrienols, and palm olein, respectively. All volunteers took one palmvitee capsule per day for 30 consecutive days. Overnight fasting blood was taken from each volunteer before and after the experiment. Serum lipids and lipoproteins were analyzed by using the enzymatic CHOD-PAP method. Our results showed that palmvitee lowered both serum total cholesterol (TC) and low-density-lipoprotein cholesterol (LDL-C) concentrations in all the volunteers. The magnitude of reduction of serum TC ranged from 5.0% to 35.9% whereas the reduction of LDL-C values ranged from 0.9% to 37.0% when compared with their respective starting values. The effect of palmvitee on triglycerides (TGs) and HDL-C was not consistent. Our results show that the palmvitee has a hypocholesterolemic effect.

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