The effect of n-3 long-chain polyunsaturated fatty acids and lipoic acid on the heart in the ovariectomized rat model of menopause.

Menopause occurs as consequence of ovarian senescence that leads to a drop of oestrogen hormone. The decreased oestrogen levels combined with the impairment of the redox system may contribute to the increased risk of postmenopausal cardiovascular disease. Supplementation with antioxidants may be an alternative to reduce cardiovascular risk. The study evaluated the effect of dietary supplementation with docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and α-lipoic acid (LA) for a period of 16 weeks on oxidative stress biomarkers in the hearts of ovariectomized 3-month-old rats. Ovariectomy did not increase the level of the damage markers malondialdehyde and carbonyl, and both were decreased by LA supplementation. Ovariectomy increased the levels of the endogenous antioxidants glutathione, vitamin C and H2O2 consumption, after restoration by DHA, EPA, and LA supplementation. Vitamin E, glutathione peroxidase, glutathione-S-transferase, and superoxide dismutase are not altered by ovariectomy. Lipid and protein damage are not increased after ovariectomy and a portion of the endogenous antioxidants concomitantly increased, suggesting that hearts may be protected by these antioxidants. DHA, EPA, and LA restored these endogenous antioxidants, showing that all evaluated supplements are effective in modulating the antioxidant redox system in the heart. LA showed additional effect on redox markers, decreasing lipid and protein damage markers.

Treatment of oxidative stress in brain of ovariectomized rats with omega-3 and lipoic acid.

SCOPE: Postmenopausal women are often affected by a group of metabolic disorders related to oxidative stress. Alternative treatments that can improve the quality of life of these women have been the subject of recent studies. The objective of this study was to evaluate the response to oxidative stress in the brains of rats following ovariectomy, and to determine enzymatic and nonenzymatic antioxidant responses when the animals received 3 months of dietary supplementation. METHODS AND RESULTS: Ovariectomy produced changes in antioxidant profiles characterized by reductions in glutathione S-transferase activity, H2 O2 consumption, superoxide dismutase activity, and vitamin C levels and increases in protein carbonylation. Docosahexaenoic fatty acid (DHA) supplementation restored these parameters to normal values and increased values of other antioxidants (glutathione peroxidase and total glutathione). However, DHA supplementation also increased protein carbonylation and lipid peroxidation. Eicosapentaenoic acid supplementation produced no changes in antioxidants, but decreased lipid peroxidation. Lipoic acid supplementation increased consumption of H2 O2 and decreased protein carbonylation and lipid peroxidation. CONCLUSION: These results suggest that the antioxidant response to omega-3 varies in different tissues, and in this study DHA treatment had a prooxidant effect in the brain. Lipoic acid treatment, on the other hand, had a protective effect, reducing markers of oxidative damage.

Alpha-lipoic acid restores tear production in an animal model of dry eye.

The tear film comprises a major mechanism for protection of the ocular surface against harmful external agents. Disruption of tear production can lead to dry eye syndrome, causing damage ranging from mild discomfort to scarring of the ocular surface with irreversible vision impairment. The production of tears by the lacrimal gland is influenced by neuroendocrine, hormonal, and immunological factors. Reactive oxygen and nitrogen species play an important role in its regulation. We assessed the effects of oxidative stress on antioxidant defenses in the lacrimal gland and ocular surface in ovariectomized rats supplemented with n-3 polyunsaturated fatty acids (n-3 PUFA) and alpha-lipoic acid (ALP). We found that n-3 PUFA did not measurably influence oxidative stress, but ALP had site-specific pro-oxidant and antioxidant effects, and was an important influence on ocular surface dry eye improvement. As an index of oxidative damage to proteins and lipids, we measured levels of carbonyl and malondialdehyde (MDA), respectively. Enzymatic antioxidant defenses were measured as total superoxide dismutase (tSOD) and glutathione peroxidase (GPx), and non-enzymatic defenses were estimated by vitamin C, total glutathione, and indirect oxide nitric levels. PUFA and ALP treatment restored lacrimal production with resulting improvement in the dry eye Schirmer test in all supplemented groups. The results indicated that reactive oxygen species resulting from oxidative stress in the lacrimal gland did not play an important role in dry eye through reactive oxygen species; however, alpha-lipoic acid altered the metabolism of reactive nitrogen species, causing increased activity of lacrimal peroxidase and improved lacrimal production.

Alteraçöes oculares associadas ao uso de Antipsicóticos / Ocular problems due to the uso of antipsychotic drugs

Os autores fazem revisÝo sobre o desenvolvimento da terapia antipsicótica, analisando o aspecto farmacodinâmico das diferentes drogas envolvidas e o surgimento de alteraSes oculares associadas, preferencialmente, ao uso das fenotiazinas...