title: Vitamin E and alpha-lipoic acid supplementation increase bleeding tendency via an intrinsic coagulation pathway.
abstract: Vitamin E and alpha-lipoic acid are potent nutritional antioxidants, and when used together, their antioxidant capabilities are improved as alpha-lipoic acid recycles vitamin E. Supplementation of vitamin E has been shown to prolong platelet aggregation but the effects of vitamin E and alpha-lipoic acid supplementation on bleeding tendency have yet to be reported. Young, male rats consumed either control diet (n=5) or vitamin E and alpha-lipoic acid-supplemented diet (n=5) for 14 weeks. Activated partial thromboplastin time (APTT) and prothrombin time (PT) were measured as markers of intrinsic and extrinsic coagulation pathways respectively in addition to lipid peroxidation (malondialdehyde). Supplementation significantly prolonged APTT (23.8+/-1.5 vs 31.4+/-1.2s, p<0.05) compared to the control diet; however, there was no significant difference in PT (27.8+/-1.5 vs 26.6+/-0.9s, p>0.05). While vitamin E was increased (p<0.05), there was no significant difference in plasma levels of malondialdehyde (p>0.05). Dietary supplementation of vitamin E and alpha-lipoic acid increases bleeding tendency via inhibition of the intrinsic coagulation pathway with no change in markers of lipid peroxidation. Such supplementation could benefit patients with cardiovascular disease who exhibit elevated levels of coagulation and oxidative stress.
authors.affiliation: School of Human Movement Studies, The University of Queensland, Brisbane, Australia.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Marsh
authors.forename: Jeff S
authors.initials: JS
authors.lastname: Coombes
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001777:Blood Coagulation / Q000187:drug effects*; D019587:Dietary Supplements; D004359:Drug Therapy, Combination; D006470:Hemorrhage / Q000139:chemically induced*; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D010314:Partial Thromboplastin Time; D011517:Prothrombin Time; D051381:Rats; D008063:Thioctic Acid / Q000494:pharmacology*; D014810:Vitamin E / Q000097:blood / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D014810:Vitamin E; D008315:Malondialdehyde; D008063:Thioctic Acid