ABSTRACT
Objective: To investigate the possible protective and/or therapeutic potentials of Dunaliella salina (D. salina) biomass, its carotenoid and polar fractions on cardiac dysfunction associated with D-galactose (D-GAL) induced aging in rats. Methods: Aging associated cardiac dysfunction was induced in rats by injection of D-GAL (200 mg/kg; i.p) for 8 weeks. D-GAL injected rats were treated with two regimens; protective regimen where D. salina biomass (250 mg/kg), its carotenoid (250 μg/kg) and polar (250 μg/kg) fractions were given orally for two weeks concurrently with D-GAL injection as well as treatment regimen where the three treatments were given orally for 28 consecutive days after D-GAL injection. Results: D-GAL injection for 8 weeks was accompanied with dramatic electrocardiographic changes as well as profound elevation in serum levels of homocysteine, creatinine kinase isoenzyme and lactate dehydrogenase in addition to the reduction of the cardiac content of glucose trasporter 4. D-GAL also induced reduction in cardiac superoxide dismutase activity and elevation of inducible nitric oxide synthetase and interleukin-6. On the other hand, oral administration of D. salina carotenoid fraction as well as the total biomass significantly attenuated the D-GAL-induced disturbances in the above mentioned parameters where the protective regimen appeared more successful in controlling the manifestations of cardiac dysfunction. The histopathological examination further emphasized the promising results. Besides, the HPLC analysis of the carotenoid fraction of D. salina revealed the presence of 2.31% β -carotene. Conclusions: D. salina carotenoid fraction as well as the total biomass ameliorate D-GAL-induced aging associated cardiac dysfunction which is attributed to the potent antioxidant activity of β -carotene.
ABSTRACT
Depression is one of the most serious and common mental diseases with major negative social consequences. Transresveratrol [trans-3,5,4´-trihydroxystilbene] is a polyphenolic compound with a broad spectrum of pharmacological activities. It has been detected in some fruits and herbs, including the Asian plant Polygonum cuspidatum. The aim of this study was to assess the antidepressant-like effect of transresveratrol in a reserpine subchronic model of depression. Depression-like behaviours were induced in rats by reserpine injection [0.25 mg/kg, subcutaneously] every 48 h, for 20 days. Transresveratrol [60 and 120 mg/kg] and fluoxetine [10 mg/kg] were administered orally daily during the 20 days of the study. Behavioural tests, namely, open-field test and forced swimming test, as well as brain neurotransmitters levels and antioxidant contents and liver functions, were assessed. Data revealed that transresveratrol improved the rats' behaviour in both the open-field test and forced swimming test, and also elevated the brain's neurotransmitter content, normalized the liver enzymes level, and improved the antioxidant status of both the brain and liver, compared with those of fluoxetine. The present study provided a clear evidence for the antidepressant-like of transresveratrol in the experimental model of depression. Further investigations are required to investigate the mechanism of action of transresveratrol as well as its applicability to be used as an antidepressant