Objective: Since it is well known that estrogen deficiency or ovariectomy (OVX) results in a reduction of sexual steroids and increased prevalence of cardiovascular diseases (CVD), it was aimed to assess the benefits of hormone replacement therapy (HRT) alone or together with antioxidant vitamins (E and C) for the protection against CVD and oxidative stress.
Methods: The effect of ovariectomy and HRT alone or combined with antioxidants (Antiox) on lipid metabolism, insulin sensitivity, oxidative stress, antioxidant and markers of CVD was examined in four groups of female Wistar rats of 10 animals each: Group 1 (sham operated); Group 2 (OVX); Group 3 (OVX + HRT); Group 4 (OVX + HRT + Antiox). After four weeks of treatment total cholesterol, HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), triglycerides (TG), Apo B lipoprotein, glucose and insulin as well as malondialdehyde (MDA; as index of lipid peroxidation), oxidized LDL (ox-LDL), homocysteine level, oxidized and reduced glutathione were determined in plasma.
Results: The lipid pattern of OVX rats showed a deviation from sham group in all lipid fractions and atherogenic indexes; LDL/HDL and TC/HDL. HRT group showed partial correction of these abnormalities and the antioxidant adjunct treatment significantly improved the lipid profile. OVX rats had significantly higher insulin and glucose levels compared to the sham group which was abolished by HRT and completely normalized by adjunct antioxidant treatment. HOMA was significantly decreased by HRT and showed normal value with adjunct antioxidant treatment. The oxidative stress parameters; MDA, ox-LDL and GSSG levels were increased, also homocysteine was greatly elevated in OVX rats. The HRT significantly corrected the levels of MDA, ox-LDL and GSSG while it had no effect on homocysteine and GSH. The adjunct antioxidant treatment potentiated the HRT and showed a significant correction of homocysteine and GSH levels.
Conclusion: Our data suggested that adjunct antioxidant treatment together with HRT may ameliorate the cardiovascular protection and improve metabolic syndrome as well as insulin resistance in OVX rats. Further studies are warranted to elucidate the beneficial role of antioxidant treatment on cardiovascular protection of menopause women.