Abstract. Menopause occurs gradually and is characterized by increased susceptibility to developing mood disorders. Several
studies have suggested that oxidative stress is implicated in the subsequent mood changes. It has been reported that quercetin
glycosides may be effective due to their antioxidant abilities. The present work aimed to find out whether quercetin able to act
against ovariectomy consequences and possible underlying mechanism(s). Animals were randomly divided into six groups of
eight rats each. Group (1) Control group (2) Sham operated group (3) Ovariectomized (OVX) group (4) OVX-Isoquercetin-treated
(10 mg/kg, i.p., dissolved in a DMSO/saline solution) group (5) OVX-estrogen-treated (subcutaneous implant of pellets (Innovative
Research of America, Toledo, OH) containing 17β-estradiol (1.5 mg/8 wk) group (6) OVX-Isoquercetin-estrogen treated group.
The treatments were initiated two week after both ovariectomy and sham operations and continued for four consecutive weeks.
Tested parameters: oxidative stress markers (MDA, GSH, SOD), inflammatory cytokines (TNF-α, IL-6) and brain monoamines
(dopamine, nor epinephrine, 5-HT). Results: Isoquercetin either alone or in combination with estrogen can improve: oxidative
stress markers (MDA, GSH, SOD), inflammatory cytokines (TNF-α, IL-6) and brain monoamines (dopamine, nor epinephrine, 5-
HT). Combination of both isoquercetin & estrogen gives the best results in most of the tested parameters especially in normalizing
IL-6 level. Concerning serotonin estrogen was as good as the combined drugs. Conclusion: Isoquercetin has an additive role with
estrogen to maintain healthy brain tissue for production of normal monoamine levels.