Page 108 - phytochemistry II -pharmD general

Although cells possess a variety of defense mechanisms and repair systems
against ROS, this can sometimes be inadequate, leading to oxidative stress.
Acute oxidative stress as well as chronic oxidative stress have been
implicated in a large number of human degenerative diseases affecting a
wide variety of physiological functions, such as atherosclerosis, diabetes,
inflammatory diseases (rheumatoid arthritis, inflammatory bowel disease,
and pancreatitis), cancer, neurological diseases, hypertension, ocular
diseases (cataract, senile muscular degeneration, and retrolental
fibroplasia), pulmonary diseases, and hematological diseases. Even aging
and age-related loss of physiological fitness have been attributed to the
chronic effects of ROS on various biological macromolecules. The delicate
balance between beneficial and harmful effects of free radicals is a very
important aspect of living organisms.
Superoxide anion is considered the “primary” reactive oxygen species and
can further interact with other molecules to generate “secondary” reactive
oxygen species, either directly or prevalently through enzyme- or metal-
catalysed processes

Function of antioxidants

The Food and Drug Administration (FDA) defines antioxidants only as dietary
supplements to be taken in addition to normal food consumption in an effort
to prevent these diseases. Antioxidants are known to play a key role in the
protective influence exerted by plant foods.

All antioxidants are working in concert as a team, the (antioxidant system),
responsible for prevention of the damaging effects of free radicals and toxic

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