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Post-stroke depression (PSD) occurs about 40% among all stroke survivors, but the effective pharmacotherapy is inadequately understood. The present study investigated the effects of a natural polyphenol trans -resveratrol (RES) on behavioral changes after middle cerebral artery occlusion (MCAO) and examined what its molecular targets may be. RES was shown to decrease the infarct size and neurological scores after MCAO, suggesting the amelioration of brain damage and motor activity. RES also reversed the depressive-like behaviors 13 days after MCAO, both in the forced swimming and sucrose consumption tests. Moreover, MCAO-induced series abnormalities related to depressive-like behaviors, such as an abnormal adrenal gland weight to body weight ratio, an increased expression of the corticotropin-releasing factor (CRF) in the frontal cortex, hippocampus and hypothalamus, the differential expression of glucocorticoid receptor (GR) in these three brain regions, and a decreased brain-derived neurotrophic factor (BDNF) level, were ameliorated after treatment with increasing doses of RES at 10, 20 and 40 mg/kg via gavage. These findings provide compelling evidence that RES protects the brain against focal cerebral ischemia-induced injury, but most of all is its antidepressant-like effect on PSD, which might at least in part be mediated by regulation of hypothalamus–pituitary–adrenal axis function. [ABSTRACT FROM AUTHOR]

Ferulic acid is a polyphenol that has antioxidant, anti-inflammatory and anticancer properties. The present study analyzed the antidepressant-like potential of ferulic acid using two well-validated mouse models of despair test, tail suspension and forced swim tests. The results suggested that ferulic acid treatment at doses of 10, 20, 40 and 80 mg/kg (p.o.) significantly reduced the immobility time in both of these two tests. These doses that affected the depressive-like behaviors did now show any effect on locomotion counts. The further neurochemical assays suggested that ferulic acid increased monoamine neurotransmitter levels in the brain regions that are relative to mood disorders: the hippocampus and frontal cortex. The increased tend to serotonin and norepinephrine was also found in the hypothalamus after higher dose of ferulic acid treatment. The subsequent study suggested that monoamine oxidase A (MAO-A) activity was inhibited in the frontal cortex and hippocampus when treatment with 40 and 80 mg/kg ferulic acid; while MAO-B activity did not change significantly. The current study provides the first lines of evidence that serotonin and norepinephrine, but not dopamine levels were elevated in mouse hippocampus and frontal cortex after ferulic acid treatment. These changes may be attributable to the inhibition of MAO-A activities in the same brain regions. [ABSTRACT FROM AUTHOR]

Patients suffering from chronic neuropathic pain are at high risk of co-morbid depression, which burdens healthcare. Trans-astaxanthin has been shown in our previous studies to exert antidepressant-like effect. This work aimed to investigate the effects of trans-astaxanthin on pain-related depressive-like behaviors in mice and explored the mechanism(s). Chronic constriction injury (CCI) model was used in this research. Chronic pain was evaluated by thermal hyperalgesia in Hargreaves test and mechanical allodynia in von Frey test, depressive-like behaviors were evaluated by immobility time in forced swim test and tail suspension test. Chronic trans-astaxanthin treatment ameliorated mechanical allodynia and thermal hyperalgesia, as well as decreasing immobility time in forced swim test and tail suspension test in CCI mice, and these actions were abolished by co-treatment with P-Chlorophenylalanine (PCPA). Subsequent study indicated that indoleamine 2,3-dioxygenase (IDO) expression increased after CCI surgery in hippocampus and spinal cord, accompanied by increase of kynurenine (KYN)/tryptophan (TRY) ratio, decrease of serotonin (5-HT)/TRY ratio and decrease of 5-HT/5-HIAA ratio. The above results affected by CCI surgery were reversed by trans-astaxanthin treatment. Moreover, trans-astaxanthin at 80 mg/kg was demonstrated to effectively antagonize IL-1β, IL-6 and TNF-α expression in hippocampus and spinal cord of CCI mice. Taken together, chronic trans -astaxanthin administration exerts therapeutic effects on thermal hyperalgesia and co-morbid depressive-like behaviors in CCI mice. These effects of trans-astaxanthin involves the serotonergic system, and also may be owing to its potent anti-inflammatory property. [ABSTRACT FROM AUTHOR]