TAP effectively prevents Ca2+-ATPase from inactivation, in the presence of promoters of lipid peroxidation or thiol reagents. In addition it prevents the depletion of cellular -SH content during peroxidation. This suggests that the antioxidant activity may be mediated through the protection of the -SH group of the enzyme. Similar observation of impairment of the function of the sarcoplasmic reticulum by oxidation of sulphydryl groups of Ca2+-ATPase by oxidative stress and partial restoration of the activity in presence of reduced thiol reagents has been reported by Scherer and Deamer (1986). Rafatullah et al.
(1990) have reported anti-ulcer activity of crude turmeric extract by the restoration of the nonprotein sulphydryl content of the glandular stomachs of rats.