Low Dose β-carotene Supplementation Diminishes Oxidative Stress in Type 2 Diabetics and Healthy Individuals

Low Dose β-carotene Supplementation Diminishes Oxidative Stress in Type 2 Diabetics and Healthy Individuals

Effect of the Supplementation With β-carotene to Type 2 Diabetic Patients and Healthy Controls on the Iron Status and Antioxidant Capacity of Plasma

Since diabetes has multiple etiologies and oxidative stress one of the proposed mechanisms, the objective is to determine the effect of supplementation with β-carotene to type 2 diabetics and healthy individuals, on iron metabolism, oxidative balance, and antioxidant plasma capacity, using doses similar to the daily nutritional requirement.

Type 2 diabetes is a chronic, multifactorial disease, and oxidative stress one of the pathophysiological mechanisms associated with its appearance and development. The objective was to determine the effect of supplementation with β-carotene to type 2 diabetics and healthy individuals, on iron metabolism, oxidative balance, and antioxidant plasma capacity, using doses similar to the daily nutritional requirement. A total of 117 volunteers participated in the study. Type 2 diabetics (34) and healthy individuals (24), received 6 mg β-carotene for 45 d, and were compared to similar non-supplemented diabetic (33) and control (26) groups. Blood samples were taken at the beginning, end and 30 days after finishing supplementation, to determine hemoglobin, hematocrit unsaturated iron binding capacity, total iron binding capacity, transferrin saturation, ferritin, glycemia, glycosylated hemoglobin, cholesterol, triglycerides, HDL, LDL, oxidized LDL, copper, zinc, TBARS, FRAP, nitrites, GPx, SOD, folates, retinol and β-carotene.

6 mg betacarotene in caplets for 45 days (daily)and reevaluate parameters 30 days after finishing supplementation

Serum iron, total iron binding capacity (TIBC) and unsaturated iron binding capacity (UIBC) were determined by the methods proposed by the International Committee of Standardization of Hematology.

Glycemia, triglycerides, total cholesterol, LDL, and HDL were determined automatically in a Ciba Corning 550 Express autoanalizer, using classic enzymatic methods for the determination of these variables.

Analyzed by a solid phase two-site enzyme immunoassay from Mercodia (Sweden), which contains 2 monoclonal antibodies directed against separated antigenic determinants on the oxidized apolipoprotein B molecule.

Were detected by the quantification of malondialdehyde present in the sample, by reacting 2 molecules of thiobarbituric acid with 1 molecule of malondialdehyde, which produces an abduct that is detected at 535 mn.

Measured after 4 and 10 min incubation, was used to determine the ability of plasma to reduce iron from ferric to ferrous state, based on the formation of a triazine-Fe+3 complex, that when reduced to Fe+2, generate a change in color that is measured at 593 nm.

It was determined by HPLC, with a reverse fase C18 column, as an indirect measure of betacarotene metabolism.

Were determined as an indirect measure of the concentration of nitric oxide, since nitrites are the stable end products of its degradation. Nitrates were reduced to nitrites by activated cadmium. Then sulfanilamide and nitrites generate a chromophore that reacts with naftilethylenediamine, to generate a product visible at 540 nm.

The method is based in the folate-dependent controlled growth of a Lactobacillus strain that is measured spectrophotometrically and quantified against a standard curve.

Inclusion Criteria: Patients with a diagnose of Type 2 diabetes mellitus of at least 5 years of diagnosis, in treatment with oral hypoglycemics Patients in regular control (once a month) in the Hospital Exclusion Criteria: Hospitalized patient Diabetic patient with diabetes related acute complications (ketoacidosis, hyperosmolar coma)in the 3 months previous to the study. Individuals with infections that required antibiotics in the 3 weeks previous to the study. Individuals with antibodies anti-insulin, autoimmune diseases or in treatment with immunosuppressive drugs. Individuals with viral infections such as hepatitis B, hematological, renal or hepatic diseases. Pregnancy

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