RESUMO
OBJECTIVE To investigated the anti-de-pressant effects of the fruit Areca catechu L.(ACL)and elucidated its potential underlying mechanism using a rat model of chronic unpredictable mild stress(CUMS).METHODS CUMS was induced in rats to establish a depression animal model for 28 d.According to the baseline sucrose preference,the male rats were divided into six different groups.They were treated with parox-etine hydrochloride,ACL,and water once a day until the behavioral tests were performed.The levels of corticoste-rone(CORT),malondialdehyde(MDA),catalase(CAT),and total superoxide dismutase(T-SOD)in serum were de-tected using a commercial kit,and the concentrations of 5-hydroxytryptamine(5-HT)and dopamine(DA)mono-amine neurotransmitters in the brain tissues were detect-ed by liquid chromatography-tandem mass spectrometry.Doublecortin(DCX)expression in the hippocampal den-tate gyrus(DG)was determined by immunofluorescence,and the relative abundance of brain-derived neurotrophic factor(BDNF),TrkB,PI3K,p-Akt/Akt,PSD-95,and p-GSK-3β/GSK-3β of brain tissues were assayed by West-ern blotting.RESULTS ACL markedly increased sucrose preference,decreased the immobility time,and short-ened the feeding latency of CUMS-induced rats.CUMS induction resulted in marked changes in the contents of the monoamine neurotransmitters(5-HT and DA)in the hippocampus and cortex of brain tissues and the levels of CORT,MDA,CAT,and T-SOD in serum,whereas ACL administration alleviated these considerable changes.ACL promoted DCX expression in DG and increased the protein levels of BDNF,TrkB,PI3K,p-Akt/Akt,PSD-95,and p-GSK-3β/GSK-3β in the brains of CUMS-induced rats.CONCLUSION Our results indicated that ACL may improve depression-like behaviors in CUMS-induced rats by decreasing the hyperfunction and oxidative stress of the hypothalamic-pituitary-adrenal axis,stimulating hippo-campal neurogenesis,and activating the BDNF signaling pathway.
RESUMO
OBJECTIVE Microgravity exerts several negative effects on the learning and memory of astro-nauts during space flight.Rg1 and Rb1,the key steroidal components of ginseng,have shown potent neuroprotec-tive effects with a high safety profile.The object of the current study is to investigate the influence of Rg1 and Rb1 on simulated microgravity-induced memory and learning dysfunction in the hindlimb suspension(HLS)rat model.METHODS The HLS rats were orally administered Rg1(30 and 60 μmol·kg-1)or Rb1(30 and 60 μmol·kg-1)for four weeks.The Morris water maze test(MWM)and reward operating conditioning reflex test(ROCR)were conducted to evaluate spatial and associative learning and memory.After the behavior tests,the serum and the prefrontal cortex(PFC)were dissected to measure the mechanism.RESULTS Rg1 and Rb1 treatment amelio-rated the cognitive deficits of HLS-exposure rats in MWM and ROCR,reduced reactive oxygen species generation and increased antioxidant enzyme activity.Rg1 and Rb1 also assisted in the recovery of mitochondrial complex Ⅰ(NADH dehydrogenase)activities and Mfn2,and decrea-sed Drp-1 expression.Furthermore,Rg1 and Rb1 reduced the ratio of Bax/Bcl-2 and the expression of cleaved-cas-pase 3,cytochrome c,increased the levels of SYN,PSD95 and activated BDNF-TrkB/PI3K-Akt pathway in the PFC.CONCLUSION Rg1 and Rb1 treatment attenuated cog-nitive deficits induced by HLS,mitigated mitochondrial dysfunction,attenuated oxidative stress,inhibited apopto-sis,and increased the synaptic plasticity,which was partly mediated by the modulation of the BDNF-TrkB/PI3K-Akt signaling.