Oxidative Stress and Enzymatic Antioxidant Status in Patients with Hypothyroidism before and after Treatment

Abstract

The present study was designed to investigate the relationship between the serum levels of oxidant-antioxidant system (malondialdehyde (MDA) level, Paraoxonase (PON1) activity, nitric oxide (NO) level and superoxide dismutase (SOD) activity) and thyroid hormone status in hypothyroidism pre and posttreatment. The study group comprised 33 patients with primary hypothyroidism. 18 of these patients were reevaluated after euthyroid state i.e. at least 6 months of thyroxine replacement. The patients were compared with 26 normal healthy controls. Serum MDA level, PON1 activity, NO level and SOD activity were measured according to an enzymatic spectrophotometric method. MDA levels were found higher in patients with hypothyroidism before the treatment than the controls. MDA levels were also found to be decreased after the treatment in patients with hypothyroidism. However MDA were found still higher than the controls after the treatment. PON1 activity was found to be lower in patients pretreatment when compared to posttreatment hypothyroidism and controls. Posttreatment of hypothyroidism mean PON1 activity significantly increased compared to pretreatment level but it was still significantly lower than control level. NO level was higher in pretreatment hypothyroidism when compared to controls. SOD activity was not found different in patients before treatment when compared to controls. SOD activity was significantly higher in after treatment when compared to both pretreatment and control levels. In conclusion, increased ROS levels in hypothyroidism may result in a pro-oxidation environment, which in turn could result in decreased antioxidant PON1 activity, increased MDA and NO levels. As a result, lipid peroxidation may have a role in the pathogenesis of the atherosclerosis in hypothyroidism.

Serum Total Antioxidant Status, Lipid Profile, Malondialdehyde and Erythrocyte Superoxide Dismutase Levels in Hashimoto Thyroiditis Patients Treated with Levothyroxine

“…Only Baskol et al studied Hashimoto thyroiditis patients both before and after levothyroxine treatment and reported that MDA was higher in hypothyroid patients and still remained higher than the control groups even after being treated with levothyroxin. 20 Our findings on increased MDA, which is a marker for increased oxidative stress are in agreement with the results of Baskol et al 20 Turkiye Klinikleri J Med Sci 2012;32 (5) Mehmetçik ve ark.…”

“…Only Baskol et al, Gerenova and Gadjeva reported on the differences in SOD levels both before and after levothyroxine treatment. 20,26 Although Gerenova and Gadjeva found an insignificant decrease in SOD levels in hypothyroid patients treated with levothyroxine, our results suggested significant decreases in the SOD levels. 26 On the contrary, Baskol et al found significant increases in SOD levels in Hashimoto thyroiditis patients treated with levothyroxine.…”

“…26 On the contrary, Baskol et al found significant increases in SOD levels in Hashimoto thyroiditis patients treated with levothyroxine. 20 Total antioxidant status measurement is informative about the total cellular antioxidant defense system against active oxygen and lipid peroxidation. It consists of a network of antioxidant enzymes and low molecular weight non-protein sulfhydryls that cooperate to keep the concentration of active oxygen species within acceptable levels.…”

Antioxidant Trace Elements and Oxidative Stress Levels Associated with Pasteurellosis in Camel-Calves (Camelus dromedarius)

“…The antioxidant enzyme activities were decreased, and then the superoxide radical and hydrogen peroxide intermediate radicals accumulate. These oxygen free-radicals could undergo the Fenton's reaction, generating hydroxyl radicals, which may lead to lipid peroxidation in cells [33]. Therefore, the reason of increased lipid peroxidation in camel-calves with pasteurellosis may be related to decreased antioxidant enzymes activity.…”

Hashimoto's Disease

“…Moreover, the components of several viruses (hepatitis C, human parvovirus B19, coxsackie and herpes viruses) were detected in the thyroid of Hashimoto's thyroiditis patients (Mori & Yoshida 2010). Moreover, the possible involvement of the oxidative stress profile in HT pathogenesis was also reported (Baskol et al, 2007;Lassouad et al, 2010).…”