Medicinal Plants Classification Biosynthesis and ... - Index of

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Rosa Martha Perez Gutierrez, Adriana Maria Neira Gonzalez et al.
capillaries. In the same rats, micronutrients inhibited increases in retinal oxidatively modified
DNA and nitrotyrosine and decreases in manganese superoxide dismutase. Diabetes-induced
alterations in the messenger RNA expression of mitochondrial electron transport complex III
(coenzyme Q cytochrome-c reductase) and inducible nitric oxide synthase were also
prevented. Age-Related Eye Disease Study-based micronutrients inhibit the development of
diabetic retinopathy in rodents by inhibiting oxidative and nitrative stress (Kowluru et al.,
2008).
Beta-carotene supplements do not appear to lower the risk of developing type 2, or adultonset,
diabetes. Researchers analyzed the development of type 2 diabetes in 22,071 healthy
US male physicians aged 40 to 84 years in a randomized, double- blind, placebo-controlled
trial, from 1982 to 1995 participating in the Physicians' Health Study, about half of whom
were taking beta-carotene supplements (50 mg on alternate days) or placebo. Over a 12-year
period, the rate of type 2 diabetes was similar in men who took beta-carotene and those who
did not (Liu et al., 1999).
-Carotene and Maculopathy
In the USA, an estimated 30% of persons 65 years and older show signs of early age
related maculopathy (ARM) or its late-stage manifestations, which are also known as agerelated
macular degeneration (AMD) (National Advisory Eye Council, 2004).
In a randomized trial conducted for a 12 years‘ period of duration from a large
population 22, 071 apparently healthy US male physicians aged 40 to 84 years. Participants
were randomly assigned to receive beta carotene (50 mg every other day) or placebo.
However, the main trial results indicated that 12 years of randomized β-carotene treatment
had no beneficial or harmful effect on any cancer or cardiovascular disease end point in the
overall population or in the 11.0% of physicians who were current smokers at baseline
(Hennekens et al., 1996). Two other randomized trials also reported no effect of beta carotene
supplementation on cancer, cardiovascular, or mortality end points (Greenberg et al., 1996;
Lee et al., 1999).
In summary, the results of this trial indicate that beta carotene supplementation for 12
years has little effect on the development of visually significant ARM in apparently healthy
men (Christen et al., 2007).
-Carotene and Pregnancy
Reducing infant mortality remains a major public health challenge in developing
countries. In recent years, attention has turned to reaching newborns with safe, efficacious
interventions to improve survival (Martines et al., 2005). Long known to reduce child
mortality over 6 months of age (Sommer and West, 1996), new observations have emerged in
recent years that vitamin A, if given as an oral supplement shortly after birth, can reduce
infant mortality. Two randomized, placebo-controlled trials in South Asia have, to date,
reported significant reductions in infant mortality after receipt of a large, oral dose of vitamin