Vanadium is a soft metal that presents anti-diabetic characteristics. A Japanese in vivo study examined the anti-diabetic activity of poly(gamma-glutamic acid)oxovanadium(IV) complex (VO(gamma-pga) compared to vanadium(IV) oxide sulfate (VS) as a control.4 Both compounds were orally administered at doses of 5 to 10 mg (0.1-0.2 mmol) V kg(-1) body mass to the KKA(y) mice for 30 days. VO(gamma-pga) normalized the hyperglycemia within 21 days, whereas VS lowered the blood glucose concentration only by a small degree. In addition, the glucose intolerance, HbA(1c) level, hyperinsulinemia, hypercholesterolemia and hyperleptinemia were significantly improved in VO(gamma-pga)-treated KKA(y) mice compared with those treated with VS. A separate study found vanadium could exert its insulin sensitizing effects through the stimulation of adiponectin through a PKB-dependent transduction pathway.5 Alpha-lipoic acid (ALA) is a natural compound with antioxidant properties. French researchers said, “ALA scavenges hydroxyl radicals, hypochlorous acid and singlet oxygen. It may also exert antioxidant effects in biological systems through transitional metal chelation. A number of experimental as well as clinical studies point to the usefulness of ALA as a therapeutic agent for such diverse conditions as diabetes, atherosclerosis, insulin resistance, neuropathy, neurodegenerative diseases and ischemia-reperfusion injury.”6 A review published in Expert Opinion on Investigational Drugs noted, “ALA has been shown to cause weight loss, ameliorate insulin resistance and atherogenic dyslipidemia, as well as to lower blood pressure, all of these being components of the metabolic syndrome.”7 A study conducted at Emory University School of Medicine, Atlanta, randomized 58 subjects with the metabolic syndrome in a double blinded manner to 150 mg/d of irbesartan (n=14), 300 mg/d of lipoic acid (n=15), both irbesartan and lipoic acid (n=15), or matching placebo (n=14) for four weeks.8 After four weeks of therapy, endothelium-dependent flow-mediated vasodilation of the brachial artery was increased by 67 percent, 44 percent and 75 pecent in the irbesartan, lipoic acid and irbesartan plus lipoic acid groups, respectively, compared with the placebo group. Treatment with irbesartan and/or lipoic acid significantly reduced plasma levels of interleukin-6 and plasminogen activator-1, and decreased 8-isoprostane levels. References on the next page...
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