Oxidative damage and the pathogenesis of menopause related disturbances and diseases

Abstract

Abstract:The postmenopausal phase of life is frequently associated in women with subjective symptoms (e.g. vasomotor) and real diseases (atherosclerosis with coronary ischemia, osteoporosis, Alzheimer-type neurodegeneration, urogenital dystrophy), which together determine the post-menopausal syndrome. Observations that oxidative damage by reactive oxygen/nitrogen species in experimental models can contribute to the pathogenesis of these disturbances stimulated research on the relationships between menopause, its endocrine deficiency, oxidative balance and the "wellness" in postmenopausal life. The connection among these events is probably due to the loss of protective actions exerted by estrogens during the fertile life. Most recent studies have revealed that estrogens exert an antioxidant action not by direct chemical neutralization of reactants as it was expected until recently but by modulating the expression of antioxidant enzymes that control levels of biological reducing agents. Also nutritional antioxidants apparently act by a similar mechanism. From this perspective it is conceivable that a cumulative control of body oxidant challenges and biological defenses could help in monitoring between "normal" and "pathological" menopause. However, as clinical studies failed to confirm this scenario in vivo, we have decided to review the existing literature to understand the causes of this discrepancy and whether this was due to methodologic reasons or to real failure of the basic hypothesis.

Prevalence of metabolic syndrome and its association with lifestyle and cardiovascular biomarkers among postmenopausal women in western Algeria

“…Oxidative stress occurs when the production of free radicals exceeds the antioxidant capacity of the system. Free‐radical‐induced damage was considered to be a contributory factor in the development of insulin resistance, diabetes mellitus, and CVD . In the present study, high consumption of pro‐oxidant foods, including polyunsaturated fatty acids, refined carbohydrates, and sugars, was found among the women with MetS.…”

“…Inflammation and oxidative stress both play important parts in the pathogenesis of MetS . In the present study, the C‐reactive protein levels were higher among the women with MetS than those without MetS.…”

Cytoprotective effect of chlorogenic acid against hydrogen peroxide-induced oxidative stress in MC3T3-E1 cells through PI3K/Akt-mediated Nrf2/HO-1 signaling pathway

“…Most of studies reported that the pathogenesis of osteoporosis is associated with oxidative stress in osteoblasts [2, 3]. Overproduction of ROS disrupts the balance between oxidation and antioxidant defense systems, leading to bone loss by promoting lipid peroxidation and lowering antioxidant enzymes, inducing apoptosis of osteoblasts and inhibiting bone formation [4–6].…”

Efecto del extracto acuoso de Tropaeolum tuberosum "mashua" sobre el deterioro de la memoria y lipoperoxidacion inducida con fluoxetina en hi­gado en Rattus rattus var. albinus ooforectomizadas

“…En esta etapa, estos cambios en las mujeres pueden deberse a múltiples factores, uno de ellos es la formación de radicales libres o las especies reactivas del oxígeno (ERO) posiblemente debido a la disminución de las concentraciones de estrógeno circulantes en sangre periférica, los cuales bajan de 100-250 pg/mL, en la vida fértil, a 10 pg/mL (4) . Las bajas concentraciones de esta hormona pueden tener efectos prooxidantes, como, por ejemplo, ruptura del material genético, formación de aductos de ADN y oxidación de las bases (5) .…”

“…Frente a este problema, el organismo se protege utilizando sustancias denominadas "antioxidantes", los cuales son compuestos que detienen el ataque y la formación de radicales libres dentro de la célula (4,6) .…”