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Back to the battle

Vitamin C recovers the mobility of blood defense cells

In those suffering from diabetes their white blood cells, given the burden of protecting the organism against external attack from substances and in the production of anti-bodies, have a greater difficulty in migrating to combat outbreaks of infection. However, a researcher at the Institute of Biomedical Sciences (ICB) of the University of São Paulo (USP), Zuleica Bruno Fortes, has proven that the administration of antioxidants, such as vitamin C (ascorbic acid) and of probucol (a drug that reduces the level of cholesterol), re-establishes the normal level of the mobility of leukocytes, the defense cells, fundamental in the inflammatory process. In rats, with experimentally induced diabetes, this experiment didn’t produce any side effects.

Zuleica analyzed the capacity of the leukocytes to displace themselves and to begin the process of defense against infections in various tissues of the rodents: skin, intestine, cingulum (cingulum) and of the skeleton muscle. With the help of drugs, she simulated in rats mellitus diabetes – characterized by excess of sugar in the blood due to the low synthesis of the pancreatic hormone insulin – and caused in them an acute inflammation using carrageenan, a chemical agent.

Using a closed TV circuit coupled to a microscope that amplified the image as high as 2,500 times, she observed, on site, what was happening in the micro veins of the tissue. Without any type of treatment, the diabetic animals sent out fewer leukocytes to the inflamed area. If they received doses of antioxidants, then the number of cells requisitioned for the task came back up to normal levels. “The treated animal begins to respond to the inflammatory stimulus as if it were not diabetic” says the researcher. The lesser capability for the migration of the white blood cells seems to be a common phenomenon in animals that have contracted the disease.

The idea to test the effect of vitamin C and of probucol – which neutralizes the negative action of the so-called free radicals, reactive species of oxygen produced in excess by the organism due to the illness, for example – came from a confirmation: in patients with diabetes, there is an increase in the generation of free radicals, which consume the antioxidants synthesized in a natural manner by the organism.

The lack of antioxidants is not the main cause of the difficulties of diabetic sufferers in mobilizing leukocytes and of subduing inflammations. The problem comes from the lack of insulin, worsened by the excess of free radicals. For this reason the researcher decided to confirm if the use of antioxidants, already tested in diabetic patients to control other dyfunctions coming from the illness, would have some influence in the capacity of mobilizing leukocytes.Zuleica made a point of not bringing up false hopes. “The use of antioxidants is a helpful treatment”, she says.

“Insulin itself, which the diabetic patient takes to control the illness, leads to the re-establishing of the capacity of migration of the leukocytes.” Even then, there could be an eventual use of these substances in the fight against infections. “Even though a patient receives the correct doses of insulin, it is highly unlikely that the diabetes will not provoke complications over a long period”, says Zuleica. One of these complications is in reality that of a lower capacity in the mobilization of white blood cells to debilitate infections.

The Project
Possible Mechanisms Involved in the Alterations of Replies to Inflammations Observed in Experiments with Mellitus Diabetes (nº 98/00314-3); Modality Regular line of research assistance; Coordinator Zuleica Bruno Fortes – ICB/USP; Investment  R$ 47,407.33 and US$ 43,000.00