Antioxidant enzymes and lipid peroxidation in endometrium of patients with polyps, myoma, hyperplasia and adenocarcinoma

Abstract

Background: Oxidative stress and impaired antioxidant system have been proposed as a potential factors involved in the pathophysiology of diverse disease states, including carcinogenesis. In this study, we explored the lipid peroxidation levels and antioxidant enzyme activities in women diagnosed with different forms of gynecological diseases in order to evaluate the antioxidant status in endometrium of such patients.

Methods: Endometrial tissues of gynecological patients with different diagnoses were collected and subjected to assays for superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and lipid hydroperoxides.

Results: Superoxide dismutase activity was significantly decreased (50% in average) in hyperplastic and adenocarcinoma patients. Activities of both glutathione peroxidase and glutathione reductase were increased 60% and 100% on average, in hyperplastic patients, while in adenocarcinoma patients only glutathione reductase activity was elevated 100%. Catalase activity was significantly decreased in adenocarcinoma patients (47%). Lipid hydroperoxides level was negatively correlated to superoxide dismutase and catalase activities, and positively correlated to glutathione peroxidase and glutathione reductase activities.

Conclusions: This study provided the first comparison of antioxidant status and lipid peroxidation in endometrial tissues of patients with polyps, myoma, hyperplasia and adenocarcinoma. The results showed that patients with premalignant (hyperplastic) and malignant (adenocarcinoma) lesions had enhanced lipid peroxidation and altered uterine antioxidant enzyme activities than patients with benign uterine diseases, polyps and myoma, although the extent of disturbance varied with the diagnosis. Further investigation is needed to clarify the mechanisms responsible for the observed alterations and whether lipid hydroperoxide levels and antioxidant enzyme activities in uterus of gynecological patients might be used as additional parameter in clinical evaluation of gynecological disorders.

Figure 1

A) LOOH concentration (nmol/mg protein) in endometrium of patients diagnosed with: polypus endometrii (PE), uterine myomatosis (UM), simple hyperplasia (SH), complex hyperplasia (CH) and adenocarcinoma endometrii (ACE). Mean LOOH concentrations (± SD) are represented by the box; medians are plotted inside a box; the whiskers extend to the 5th and 95th percentiles. Values which are not sharing the same letter (a, b) are significantly different (p < 0.05). B) Relative values of LOOH concentration in the examined diagnosis, where PE was taken as 100%.

Figure 2

A) SOD activity (U/mg protein) in endometrium of patients diagnosed with: polypus endometrii (PE), uterine myomatosis (UM), simple hyperplasia (SH), complex hyperplasia (CH) and adenocarcinoma endometrii (ACE). Mean SOD activities (± SD) are represented by the box; medians are plotted inside a box; the whiskers extend to the 5th and 95th percentiles. Values which are not sharing the same letter (a, b) are significantly different (p < 0.05). B) Relative values of SOD activity in the examined diagnosis, where PE was taken as 100%.

Figure 3

A) CAT activity (U/mg protein) in endometrium of patients diagnosed with: polypus endometrii (PE), uterine myomatosis (UM), simple hyperplasia (SH), complex hyperplasia (CH) and adenocarcinoma endometrii (ACE). Mean CAT activities (± SD) are represented by the box; medians are plotted inside a box; the whiskers extend to the 5th and 95th percentiles. Values which are not sharing the same letter (a, b) are significantly different (p < 0.05). B) Relative values of CAT activity in the examined diagnosis, where PE was taken as 100%.

Figure 4

A) GPx activity (mU/mg protein) in endometrium of patients diagnosed with: polypus endometrii (PE), uterine myomatosis (UM), simple hyperplasia (SH), complex hyperplasia (CH) and adenocarcinoma endometrii (ACE). Mean GPx activities (± SD) are represented by the box; medians are plotted inside a box; the whiskers extend to the 5th and 95th percentiles. Values which are not sharing the same letter (a, b, c) are significantly different (p < 0.05). B) Relative values of GPx activity in the examined diagnosis, where PE was taken as 100%.

Figure 5

A) GR activity (mU/mg protein) in endometrium of patients diagnosed with: polypus endometrii (PE), uterine myomatosis (UM), simple hyperplasia (SH), complex hyperplasia (CH) and adenocarcinoma endometrii (ACE). Mean GR activities (± SD) are represented by the box; medians are plotted inside a box; the whiskers extend to the 5th and 95th percentiles. Values which are not sharing the same letter (a, b) are significantly different (p < 0.05). B) Relative values of GR activity in the examined diagnosis, where PE was taken as 100%.

Figure 6

Scatter plot of SOD (A), CAT (B), GPx (C), and GR (D) activities against LOOH level.