Thiol-Status (Sulfhydryl-Status Test) photometric

Oxidative stress, or the production of oxygen-centered free radicals, has been hypothesised
as the major source of DNA damage that in turn can lead to altered genetic
expression, disease, and aging of humans.
Serum protein thiol levels in blood are a direct measure of the in vivo reduction/oxidation
(redox) status in humans, because thiols react readily with oxygen-containing
free radicals to form disulfides. Moreover, serum thiols also reflect DNA repair capacity
and the possible eventual accumulation of genetic damage, since a key DNA repair
enzyme, poly ADP-ribose polymerase (PARP), is thiol/disulfide redox regulated.
Serum protein thiols can possibly be used to estimate individual aging status. Data
from Banne et al. (2003) strongly confirm an important role of oxidative stress in human
disease development, and identify serum thiol status as a potential biochemical
endpoint useful in the assessment of aging.