1. ABSTRACT
Heavy metals compromise the health of an individual by depleting the antioxidant source in the
body which include thiol proteins, vitamins and polyphenols. Thiol proteins is the main antioxidant
in the body of which reduced glutathione (GSH) is the major component. GSH serves as a barrier
to abate the toxic effect of these metals thus preventing the formation of reactive oxygen species
(ROS) which leads to oxidative stress. This study sought to ascertain the antioxidant capacity of
GSH when it binds to the following heavy metals (cadmium, arsenic, chromium, nickel and lead)
in an aqueous media. The antioxidant capacity of GSH when complexed with the selected heavy
metals using the Ellman’s method and the reduction potential determined using the Nernst
equation. The results indicate that all five heavy metals were toxic and had higher depleting action
on GSH. Nickel had the highest positive reduction potential followed by chromium, arsenic, lead
and cadmium.