Antidepressant-like effect of geniposide on chronic unpredictable mild stress-induced depressive rats by regulating the hypothalamus-pituitary-adrenal axis.

Geniposide as the major active component of Gardenia jasminoides Ellis has neuroprotective activity. This study elucidated the potential antidepressant-like effect of geniposide and its related mechanisms using a depression rat model induced by 3 consecutive weeks of chronic unpredictable mild stress (CUMS). Sucrose preference test, open field test (OFT) and forced swimming test (FST) were applied to evaluate the antidepressant effect of geniposide. Adrenocorticotropic hormone (ACTH) and corticosterone (CORT) serum levels, adrenal gland index and hypothalamic corticotrophin-releasing hormone (CRH) mRNA expression were measured to assess the activity of hypothalamus-pituitary-adrenal (HPA) axis. Hypothalamic glucocorticoid receptor α (GRα) mRNA expression and GRα protein expression in hypothalamic paraventricular nucleus (PVN) were also determined by real-time PCR and immunohistochemistry, respectively. We found that geniposide (25, 50, 100mg/kg) treatment reversed the CUMS-induced behavioral abnormalities, as suggested by increased sucrose intake, improved crossing and rearing behavior in OFT, shortened immobility and prolonged swimming time in FST. Additionally, geniposide treatment normalized the CUMS-induced hyperactivity of HPA axis, as evidenced by reduced CORT serum level, adrenal gland index and hypothalamic CRH mRNA expression, with no significant effect on ACTH serum level. Moreover, geniposide treatment upregulated the hypothalamic GRα mRNA level and GRα protein expression in PVN, suggesting geniposide could recover the impaired GRα negative feedback on CRH expression and HPA axis. These aforementioned therapeutic effects of geniposide were essentially similar to fluoxetine. Our results indicated that geniposide possessed potent antidepressant-like properties that may be mediated by its effects on the HPA axis.

Cai L ，Li R ，Tang WJ ，Meng G ，Hu XY ，Wu TN ... -  《-》

Antidepressant-like effects of penta-acetyl geniposide in chronic unpredictable mild stress-induced depression rat model: Involvement of inhibiting neuroinflammation in prefrontal cortex and regulating hypothalamic-pituitaryadrenal axis.

We previously reported that penta-acetyl geniposide ((Ac)5GP, an acetylated derivative of geniposide) exhibited better pharmacological functions than geniposide, a major active component of Gardenia jasminoides Ellis. This study demonstrated the antidepressant-like effects of (Ac)5GP and its involved mechanisms using a rat depression model caused by chronic unpredictable mild stress (CUMS). Behavioral tests including sucrose preference, open field and forced swimming were applied to evaluate depression symptoms. IL-1β, IL-6 and TNF-α mRNA and protein levels in prefrontal cortex (PFC) were respectively measured by quantitative PCR and ELISA. The protein levels of IκBα, p-IκBα, NF-κB p65, NLRP3, pro- and mature-IL-1β in PFC were determined by western blot. The activity of hypothalamic-pituitaryadrenal (HPA) axis was also measured. (Ac)5GP treatment alleviated the CUMS-induced depressive-like behaviors in rats, as indicated by increased sucrose intake, increased total crossing and rearing numbers, improved central activity and reduced immobility time. (Ac)5GP reversed the CUMS-induced elevations of IL-1β, IL-6 and TNF-α mRNA and protein levels in PFC. (Ac)5GP reduced degradation and phosphorylation of IκBα and protein level of nuclear NF-κB p65 in PFC. (Ac)5GP also decreased the mRNA and protein levels of NLRP3 and reduced the ratio of mature-IL-1β protein over total IL-1β protein (pro-IL-1β + mature-IL-1β) in PFC. Moreover, (Ac)5GP reduced serum levels of adrenocorticotropic hormone/corticosterone and mRNA level of hypothalamic corticotrophin-releasing hormone. In conclusion, (Ac)5GP treatment improved the depressive-like behaviors in CUMS rats perhaps by suppressing neuroinflammation in PFC and inhibiting activations of NF-κB and NLRP3 and also attenuating HPA axis hyperactivity.

Cai L ，Mu YR ，Liu MM ，Tang WJ ，Li R ... -  《-》

Ro41-5253, a selective antagonist of retinoic acid receptor α, ameliorates chronic unpredictable mild stress-induced depressive-like behaviors in rats: Involvement of regulating HPA axis and improving hippocampal neuronal deficits.

Accumulating reports have highlighted an association between excess retinoids and depression development. Retinoic acid receptor α (RARα) is implicated in the activation of hypothalamus-pituitary-adrenal (HPA) axis and closely involved in the etiology of depression, suggesting it might be a novel target of antidepressant. This study investigated the antidepressant potential of Ro41-5253 (a selective RARα antagonist) and related mechanisms using a depression rat model imitated by social isolation and chronic unpredicted mild stress (CUMS). Sucrose preference test (SPT), open field test (OFT) and forced swimming test (FST) were applied to assess the antidepressant-like effect. HPA axis activity, RARα expression in hypothalamic paraventricular nucleus (PVN) and hypothalamus, and protein levels of brain-derived neurotrophic factor (BDNF) and synapse-related proteins (PSD95, SYP, MAP2) in hippocampus were measured, respectively. We found that Ro41-5253 treatment ameliorated the depressive-like behaviors in CUMS rats, as evidenced by increased sucrose preference in SPT, raised numbers of crossing and rearing in OFT, reduced immobility time and prolonged swimming time in FST. The HPA axis hyperactivity was attenuated by Ro41-5253 (1 mg/kg) treatment, indicated by reduced serum corticosterone level, decreased adrenal gland index, reduced corticotrophin-releasing hormone protein level in hypothalamus, and recovered hypothalamic glucocorticoid receptor protein level. In addition, Ro41-5253 (1 mg/kg) treatment downregulated RARα protein expression in hypothalamic PVN and hypothalamus, and increased the protein levels of BDNF, PSD95, SYP and MAP2 in the hippocampus. We concluded that Ro41-5253 had antidepressant-like effects on CUMS rats by downregulating HPA axis hyperactivity and improving the hippocampal neuronal deficits.

Ke Q ，Li R ，Cai L ，Wu SD ，Li CM ... -  《-》

Antidepressant-like effect of the water extract of the fixed combination of Gardenia jasminoides, Citrus aurantium and Magnolia officinalis in a rat model of chronic unpredictable mild stress.

Water extract of the fixed combination of Gardenia jasminoides Ellis fruit, Citrus aurantium L. fruit and Magnolia officinalis Rehd. et Wils. bark, traditional name - Zhi-Zi-Hou-Po (ZZHPD) is used for treatment of depressive-like symptoms in traditional Chinese medicine for centuries. The present study aimed to explore antidepressant-like effects and potential mechanisms of ZZHPD in a rat model of chronic unpredictable mild stress (CUMS). Antidepressant-like effects of ZZHPD were investigated through behavioral tests, and potential mechanism was assessed by neuroendocrine system, neurotrophin and hippocampal neurogenesis. Antidepressant-like effects of ZZHPD (3.66, 7.32 and 14.64 g/kg/day) were estimated through coat state test, sucrose preference test, forced swimming test and open-field test. Effects of ZZHPD on hypothalamic-pituitary-adrenal (HPA) axis were evaluated by hormones measurement and dexamethasone suppression test. In addition, the expression of brain-derived neurotrophic factor (BDNF) in hippocampus was measured, as well as hippocampal neurogenesis was investigated by doublecortin (DCX) and 5-bromo-2-deoxyuridine/neuronal nuclei (BrdU/NeuN). The results demonstrated that ZZHPD significantly reversed the depressive-like behaviors, normalized the levels of adrenocorticotropic hormone (ACTH) and corticosterone (CORT), restored the negative feedback loop of HPA axis and improved the levels of BDNF, DCX and BrdU/NeuN compared with those in CUMS-induced rats. The above results revealed that ZZHPD exerted antidepressant-like effects possibly by normalizing HPA axis function, increasing expression of BDNF in hippocampus and promoting hippocampal neurogenesis.

Xing H ，Zhang K ，Zhang R ，Shi H ，Bi K ，Chen X ... -  《-》

Crassifoside H improve the depressive-like behavior of rats under chronic unpredictable mild stress: Possible involved mechanisms.

Crassifoside (CH) is a novel chlorine-containing compound isolated from rhizomes of Curculigo glabrescens. This study aimed to explore the antidepressant-like effect of CH and involved mechanisms. A rat depression model was established using chronic unpredictable mild stress (CUMS) paradigm. Behavioral tests including sucrose preference test (SPT), open field test (OFT) and forced swimming test (FST) were used to evaluate the antidepressant-like effect of CH. The levels of plasma corticosterone (CORT) and corticotrophin-releasing factor (CRF) in hypothalamus were measured to determine the activity of hypothalamic pituitary-adrenal (HPA) axis. Protein expression of 5-hydroxytryptamine 1A (5-HT1A) receptor, brain-derived neurotrophic factor (BDNF), as well as the total and phosphorylated extracellular signal-regulated kinase (ERK)1/2 in hippocampus were also analyzed by Western blotting. The CH administration effectively ameliorated the depressive-like behaviors of CUMS rats, as indicated by the increased sucrose intake in SPT, reduced immobility time in FST, and the increased rearing and grooming numbers, spent more time in inner zone and less time in outer zone in OFT. CH improved CUMS-induced HPA axis hyperactivity by reduced plasma CORT and CRH expression in hypothalamus. Moreover, CH reversed CUMS-induced decrease of 5-HT1A receptor expression, and up-regulated BDNF and phosphorylated-ERK1/2 levels in hippocampus. These findings suggest that CH improved depressive behaviors of CUMS rats by modulating of HPA axis dysfunction, increasing 5-HT1A receptor expression, and activating BDNF-ERK signaling pathway.

Zhang Y ，Ge JF ，Wang FF ，Liu F ，Shi C ，Li N ... -  《-》