Background: It is difficult to think of a disease in the etiology of which free radicals would not be involved. The human body has a number of endogenous free-radi-cal scavenging systems to avoid harm that can lead to any disease including cancer. This study aims to measure the total antioxidative status (TAS), in particular the activities of HDL-associated antioxidative enzymes paraoxonase (PON1), arylesterase (ARE), and total thiol levels (Ttl) in bladder cancer (BC) patients for the first time in literature.
Methods: Forty two male patients (mean age, 66.6 ± 12.7 years) with BC who had pres-ented at the Urology Outpatient Clinic were prospectively included in the study. Forty age- and gender-matched healthy control subjects (mean age 65 ± 7.4 years) were also enrolled for comparison. Analysis of PON1, ARE activities, measurement of TAS, and Ttl of serum were carried out using colorimetric measurement methods. Statistical analyses were performed using the MedCalc statistical software program.
Results: ARE enzyme activity and Ttl levels were significantly lower in patients with BC compared to controls (p = 0.03; p = 0.02, respectively), whereas PON1 en-zyme activity and TAS did not show significant differences. Ttl levels were lower in patients with a high grade cancer compared to those with a low grade cancer (p = 0.03).
Conclusions: Antioxidant measurements might be essential in routine clinical use, not only as cancer disease markers but also as major actors in the management of antioxidant remedies in the very near future. Our findings showed that determina-tion of ARE enzyme activity and Ttl levels were more precise than PON1 enzyme activ-ity or TAS measurements, particularly in BC patients. When composing a marker pa-nel, it should be kept in mind that determination of antioxidant levels based mere-ly on TAS or PON1 activity may be deceptive and must include ARE enzyme activity and/or Ttl measurements. However, longterm clinical studies are needed to clarify the pathophysiological role of serum antioxidative levels and HDL-associated PON1 activity in BC patients.