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Improvement in Plasma Antioxidants is Related to Decreased Electronegative LDL (LDL-) Levels in Supplemented Hypercholesterolemic Elderly Subjects
Gomes, L.F.1; Simon-Giavarotti, K.A.2; Rodrigues, L.3; Alves, A.F.1; Pereira, E.M.1; Peres, C.A.4; Ramos, L.R.4; Junqueira, V.B.C.2
1Depto. Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, USP; 2Depto. de Medicina, UNIFESP; 3VITÆ – cromatografia líquida em análises clínicas ltda.; 4Depto de Medicina Preventiva, UNIFESP, São Paulo, Brazil.
An antioxidant supplementation study was carried out in a group of 100 hypercholesterolemic (HC) elderly subjects, in order to assess the effect of both a combination of these substances, and different doses upon in vivo LDL oxidation, as proposed in the antioxidant network model by Packer (1992). Initial plasma levels of electronegative LDL (LDL-) and molecular antioxidants were measured by HPLC techniques; LDL-cholesterol oxidability was determined by conjugated dienes formation in the isolated LDL fraction challenged by copper ions, and neutrophil respiratory burst was studied ex-vivo by luminol enhanced chemiluminescence, during zymosan phagocytosis. Lag time for in vitro LDL oxidation was found to positively correlate with ubiquinol-10 levels (p=0,008); LDL- and a-tocopherol levels showed an inverse and significant correlation (p= 0.018). The study design included a random distribution of individuals into five groups for a double-blind, placebo controlled supplementation trial. A 180-day supplementation scheme was carried out. All subjects took three tablets of commercially available supplements daily, containing either a mixture of antioxidant vitamins and metals (Vitergan zinc plusä, taken in a single or double dose), coenzyme Q10 (Vinocard Q10ä, single dose), or placebo. It was demonstrated that plasma levels of antioxidant vitamins were increased among the subjects taking two Vitergan zinc plusä tablets. Q10 coenzyme was increased only among those taking two Vitergan zinc plusä and one Vinocard Q10ä tablet. Plasma LDL- levels decrease was also dependent on the intake of two Vitergan zinc plusä, either with or without one Vinocard Q10ä tablet. Lower intakes were ineffective. Moreover, neutrophil respiratory burst was found to be decreased by the proposed antioxidant therapy. This decrease was evidenced by the inverse correlations found between antioxidant vitamin level changes and respiratory burst activity. These results highlight the physiological significance of a-tocopherol and ubiquinol-10 levels on LDL- levels and neutrophil respiratory burst, and the weakness of the LDL-cholesterol oxidability as a probe for in vivo LDL oxidation (FAPESP, CNPq, Marjan Indústria Farmacêutica).
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