Antidepressant-like effects of water extract of Cordyceps militaris (Linn.) Link by modulation of ROCK2/PTEN/Akt signaling in an unpredictable chronic mild stress-induced animal model.

ETHNOPHARMACOLOGY RELEVANCE: Cordyceps militaris (Linn.) Link (CM) is a medicinal mushroom traditionally used in tonics for treating several neurological disorders, including epilepsy and anxiety, in Asia. Reports have shown that CM has anti-inflammatory and anti-oxidative effects and may be beneficial for depression management. AIM OF THE STUDY: This study aimed to investigate the potential of CM as an antidepressant for a long-term unpredictable chronic mild stress (UCMS) rodent models and explore its underlying mechanisms. MATERIALS AND METHODS: Rats were orally administered with 125 (low, L), 250 (medium, M), and 500 (high, H) mg/kg bodyweight (bw) of the water extract of CM (WCM) for 35 consecutive days in the UCMS protocol. The levels of cerebral serotonin (5-HT), dopamine (DA), and metabolites in the frontal cortex of the rats were measured. Blood was collected to investigate the levels of proinflammatory cytokines, and the brain was dissected to assay the stress-associated ROCK2/PTEN/Akt signaling. RESULTS: All doses of the WCM prevented abnormal behaviors induced by UCMS, including anhedonia and hypoactivity. The LWCM treatment reduced the turnover rate of 5-HT, and all doses of the WCM reduced the turnover rate of DA in the frontal cortex. The LWCM also attenuated the elevation of serum IL-1ß induced by chronic stress. All doses of the WCM attenuated the ROCK2 protein hyperactivation, and the LWCM further increased the down-regulation of p-Akt/Akt signaling. CONCLUSION: The WCM has antidepressant-like effects, which may result from the regulation of the stress-related ROCK2/PTEN/Akt pathway. Therefore, the WCM may be developed and used for the complementary treatment of depression.

Poria cocos water extract ameliorates the behavioral deficits induced by unpredictable chronic mild stress in rats by down-regulating inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Poria cocos is a medicinal mushroom of the Polyporaceae family with antioxidant and anti-inflammatory activities, which has been used for its sedative, diuretic and tonic effects in traditional medicine for several hundred years. AIM OF STUDY: Considering that depression is an inflammatory related mental disease, this study investigated the antidepressant-like effects of water extract of P. cocos in a rodent animal model. MATERIALS AND METHODS: Rats that were exposed to a forced swimming test (FST) for 28 consecutive days, and unpredictable chronic mild stress (UCMS) for five weeks underwent treatment with P. cocos water extract (PCW) (doses: 100, 300 and 900 mg/kg body weight [bw]; administered by gavage). Dopamine (DA), serotonin (5-HT) and their metabolites in the frontal cortex of rats were measured. RESULTS: Our results firstly showed that sucrose preference during the UCMS paradigm was increased and immobility time in the FST was reduced with administration of PCW. In addition, PCW significantly attenuated UCMS-induced turnover rate of DA and 5-HT in the frontal cortex. Moreover, PCW inhibited UCMS-induced activated inflammatory response, reflected by reduced expression in the frontal cortex of p38, NF-κB and TNF-α. CONCLUSIONS: Our results strongly suggest that PCW exhibits a potent antidepressant-like effect via regulation of monoaminergic neurotransmission and inactivation of inflammation, and that P. cocos may be considered as a traditional herbal potential medicine for the treatment of depression.