心脑欣胶囊对慢性抑郁大鼠的作用研究

目的:研究心脑欣胶囊对不可预知慢性应激抑郁模型大鼠抗抑郁作用及其可能的作用机制。方法:采用慢性不可预知应激刺激的方式建立大鼠慢性应激抑郁模型。通过开野、糖水偏好、强迫游泳、悬尾等实验观察心脑欣胶囊对慢性抑郁大鼠行为学的影响;观察心脑欣胶囊对慢性抑郁大鼠血清皮质酮含量和海马组织单胺氧化酶(MAO)、诱导型一氧化氮合酶(iNOS)及一氧化氮(NO)水平的影响。结果:心脑欣胶囊可明显提高慢性抑郁大鼠水平得分和垂直得分、糖水偏好程度,显著降低慢性抑郁大鼠强迫游泳、悬尾实验不动时间,显著降低慢性抑郁大鼠血清皮质酮含量,显著抑制其海马组织MAO、iNOS的活力和降低NO含量。结论:心脑欣胶囊对慢性抑郁大鼠具有明显的抗抑郁作用,其机制可能与抑制MAO、iNOS活性,降低皮质酮和NO水平,减轻海马损伤等有关。     

淫羊藿苷抗抑郁及对皮质酮致PC12细胞损伤的保护作用研究

目的：研究淫羊藿苷的抗抑郁及对皮质酮致PC12细胞损伤的保护作用。方法：采用大／小鼠强迫游泳、小鼠悬尾三种实验模型,将动物随机分为对照组、淫羊藿苷低剂量组、淫羊藿苷高剂量组、阿米替林组,观察药物对大／小鼠强迫游泳不动时间、小鼠悬尾不动时间的影响;并在细胞水平建立皮质酮损伤PC12细胞模型,观察淫羊藿苷的细胞保护作用。结果：在大／小鼠强迫游泳和小鼠悬尾实验中,淫羊藿苷可显著缩短大／小鼠的强迫游泳不动时间和小鼠悬尾不动时间,与对照组相比差异有统计学意义（P〈0．05）;在皮质酮损伤PC12细胞的模型上,淫羊藿苷可显著提高PC12细胞的存活率,拮抗皮质酮诱导的细胞损伤作用。结论：淫羊藿苷具有明显的抗抑郁效果,其抗抑郁作用与神经细胞保护作用有关。     

藏药佐太的抗抑郁抗焦虑作用研究

目的 观察藏药佐太的抗抑郁和抗焦虑作用,并探讨其可能作用机制。方法 1）初步评价实验：在小鼠ig给予6.07、60.70、303.49、606.97 mg/kg佐太14 d后,通过强迫游泳实验和开场实验初步评价佐太对抑郁和焦虑的影响,同时通过检测小鼠血清中5-羟色胺（5-HT）和去甲肾上腺素（NE）水平来探讨佐太产生影响的可能作用机制。2）不可预测性慢性温和应激模型（CUMS）实验：建立CUMS模型,ig给予6.07、60.70、606.97 mg/kg佐太后,通过小鼠体质量变化、糖水偏爱实验、小鼠悬尾实验、开场实验和埋珠实验评价佐太对CUMS模型小鼠的抗抑郁和抗焦虑作用,同时检测小鼠血清中皮质酮（CORT）、促肾上腺皮质激素（ACTH）和下丘脑中促肾上腺皮质激素释放激素（CRH）水平,测定佐太对CUMS模型小鼠下丘脑-垂体-肾上腺（HPA）轴的影响。结果 1）佐太能够显著减少小鼠强迫游泳实验中不动时间（6.07、60.70、303.49、606.97 mg/kg）;增加小鼠在开场实验中中央区停留时间百分率（606.97 mg/kg）和中央区运动百分比（303.49、606.97 mg/kg）;增加小鼠血清中5-HT（6.07、606.97 mg/kg）和NE（6.07、303.49、606.97 mg/kg）水平。2）CUMS实验中,与对照组比较,经过42 d CUMS慢性应激小鼠表现出明显的抑郁和焦虑样行为,包括糖水偏爱率的降低、悬尾不动时间显著增加、开场实验中运动时间、中央区域停留时间及运动距离的减少和周边区域运动距离的增加、埋珠实验中埋珠个数的增加。而ig给予佐太（6.07、60.70、606.97 mg/kg）能够显著改善CUMS模型引起的上述症状,并且佐太（6.07、60.70 mg/kg）能够显著降低CORT、ACTH和CRH水平,抑制CUMS模型引起的HPA轴亢进。结论 佐太具有一定的抗抑郁和抗焦虑作用,并且其作用机制可能与升高5-HT、NE水平和抑制HPA轴亢进有关。     

解郁汤对慢性应激抑郁模型小鼠的抗抑郁作用及机制研究

目的：探讨解郁汤的抗抑郁作用及可能机制。方法：以慢性轻度不可预见性应激方法建立小鼠抑郁症模型,以糖水消耗、悬尾实验、强迫游泳实验、开野实验进行行为学评分,并通过UPLC—T—QMS系统检测其脑内单胺类神经递质的含量,观察模型小鼠给药前后的变化。通过免疫组化检测小鼠海马区BDNF以及5-Brdu表达。结果：与空白组相比．模型组的小鼠蔗糖水消耗量明显下降,强迫游泳不动时间、悬尾不动时间均显著增加,交叉次数、直立次数显著减少,脑内的去甲肾上腺素、5-羟色胺、5-羟色胺吲哚乙酸含量降低（P〈0．05）。与模型组相比,解郁汤组小鼠蔗糖水消耗量显著升高,强迫游泳不动时间、悬尾不动时间均显著减少（P〈0．05）。解郁汤能显著增加大鼠脑内去甲肾上腺素、5-羟色胺、5-羟色胺吲哚乙酸含量（P〈0．05）。解郁汤能增加小鼠脑内海马区BDNF以及5-Brdu表达。结论：解郁汤具有抗抑郁作用,其作用机制可能与调节中枢单胺类神经递质的调节以及促进海马神经元再生有关。     

天麻素对抑郁症模型小鼠抑郁行为及其相关细胞因子表达的影响

目的观察天麻素的抗抑郁作用,并探讨其可能作用机制。方法采用慢性不可预知性温和应激(CUMS)制备小鼠抑郁症模型,腹腔注射天麻素(gastrodin,200 mg·kg~(-1))和丙咪嗪(20 mg·kg~(-1))后,通过小鼠体重测试、旷场实验、悬尾实验、强迫游泳实验来评价天麻素对CUMS模型小鼠的抗抑郁作用,同时通过ELISA检测小鼠血清中TNF-α、IL-1β和海马组织炎性因子TNF-α、IL-6、IL-17、IL-1β以及脑源性神经营养因子(BDNF)的表达。结果与正常组比较,CUMS 42 d后,小鼠表现出明显的抑郁样行为,表现为体重变化减少,小鼠悬尾实验和强迫游泳实验中的不动时间增加,但对其运动能力没有影响;与模型组比较,天麻素组小鼠的抑郁样行为有所改善,表现为体重变化有上升的趋势,小鼠悬尾实验和强迫游泳实验中小鼠的不动时间有所下降,进一步检测显示,天麻素组小鼠血清中TNF-α、IL-1β和海马组织炎性因子TNF-α、IL-6、IL-17、IL-1β的含量明显降低,BDNF的含量显著升高。结论天麻素具有一定的抗抑郁作用,并且其作用机制可能与降低海马组织炎性因子TNF-α、IL-6、IL-17、IL-1β水平和增加BDNF的含量有关。     

元宝草激活神经营养系统改善抑郁样行为的机制研究

目的 本文探讨了金丝桃属植物元宝草乙醇提取物(EHS)的抗抑郁样作用及其机制。方法 采用小鼠悬尾实验(TST)和强迫游泳实验(FST)评价EHS急性给药(100、200和400 mg·kg^-1)对小鼠不动时间的影响，采用开场实验(OFT)评价小鼠的自发活动状态。此外，在慢性温和应激(CMS)大鼠中，测定EHS慢性给药(50、100和200 mg·kg^-1)对糖水偏好、血清皮质酮、额叶皮层和海马脑源性神经营养因子(BDNF)表达的影响。结果 EHS急性给药(200和400 mg·kg^-1)显著减少了TST和FST小鼠的不动时间，而不改变小鼠的自发活动行为。此外，EHS慢性治疗(100和200 mg·kg^-1)逆转了CMS大鼠糖水偏好的降低。此外，EHS降低了大鼠的血清皮质酮含量，提高了额叶皮层和海马区的BDNF水平。结论 EHS的抗抑郁作用与激活神经营养系统相关。     

芍药苷抗抑郁作用的实验研究

目的 研究芍药苷的抗抑郁作用,并对其作用机制进行初步探讨.方法 采用小鼠强迫游泳、小鼠悬尾实验和体外培养PC12细胞的方法,观察芍药苷对小鼠游泳不动时间、悬尾不动时间的影响以及对皮质酮损伤PC12细胞存活率的影响.结果 芍药苷连续给药一周后,能明显缩短小鼠在行为学实验中的不动状态时间,并能拮抗皮质酮诱导的神经毒作用,提高PC12细胞的存活率.结论 芍药苷具有明显的抗抑郁作用,其机制可能与细胞保护作用有关.     

枳壳提取物抗抑郁作用及其机制探讨

目的：探讨枳壳乙醇提取物对慢性轻度不可预见性的应激（CUMS）大鼠干预作用及其机制。方法：通过21dCUMS方法建立抑郁模型,造模的同时灌胃枳壳乙醇提取物（5、10和20g／kg）。采用糖水偏好和强迫游泳评价大鼠抑郁行为,以胃排空和肠推力评价大鼠胃动力变化,采集全血测皮质酮（COR）,采用逆转录一聚合酶链反应（RT—PCR）法测定海马糖皮质激素受体（GR）、盐皮质受体（MR）inRNA、皮层和海马的脑源性神经营养因子（BDNF）ITIRNA表达。结果：与模型组比较,枳壳10、20g／kg显著提高抑郁大鼠的糖水偏好（P〈0．05,P〈0．01）,显著延长强迫游泳测试中的不动时间（P〈0．05,P〈0．01）。枳壳20g／kg显著提高大鼠胃动力（P〈0．05）。枳壳10、20g／kg显著上调海马GRmR—NA表达,降低血浆COR浓度,并上调皮层和海马的BDNFmRNA表达水平（P〈0．05,P〈0．01）。结论：枳壳乙醇提取物的抗抑郁作用可能与提高大鼠胃动力,上调海马GRmRNA、皮层和海马的BDNFmRNA表达有关。     

豆腐果苷抗抑郁作用的初步研究

目的初步探讨豆腐果苷的抗抑郁作用。方法采用小鼠悬尾实验及小鼠强迫游泳实验方法观察豆腐果苷的抗抑郁作用。结果在小鼠悬尾实验和小鼠强迫游泳实验中,豆腐果苷在20、30mg/kg剂量下能明显缩短小鼠的悬尾不动时间,在30、40mg/kg剂量下能明显缩短小鼠强迫游泳的不动时间。结论豆腐果苷在“行为绝望”动物模型中呈现抗抑郁作用,且量效曲线呈现行为学特有的U型曲线特征。     

还少胶囊抗抑郁作用的实验研究

目的：测定还少胶囊对抑郁小鼠行为学、生化指标的影响，证实还少胶囊具有抗抑郁疗效。方法：开场实验测定还少胶囊对正常小鼠自主活动能力的影响。建立小鼠悬尾、强迫游泳模型，测定还少胶囊对抑郁小鼠行为学、脑部单胺类神经递质、肝脏丙二醛和超氧化物歧化酶含量的影响。结果：经过7天给药，小鼠自主活动能力无显著改变。悬尾、强迫游泳实验中动物不动时间均显著减少。与正常组对比，还少胶囊正常组大部分生化指标改变不显著；与模型组对比，还少胶囊模型组能显著增加中枢五羟色胺（5-HT）和去甲肾上腺素（NE）含量，减少肝脏丙二醛（MDA）和超氧化物歧化酶（SOD）含量，且中、低剂量时效果更好，优于氟西汀。结论：还少胶囊具有良好抗抑郁作用，对正常动物相关生化指标影响很小，且无中枢神经兴奋作用。     

Orcinol glucoside produces antidepressant effects by blocking the behavioural and neuronal deficits caused by chronic stress

This study focused on the antidepressant potential of orcinol glucoside (OG) and its possible mechanisms of action. We established a depressed rat model using 3 consecutive weeks of chronic unpredictable mild stress (CUMS). The antidepressant-like effect of OG was revealed using the sucrose preference test, the open field test, the forced swimming test (FST), and the tail suspension test (TST). The activity of the hypothalamic–pituitary–adrenal (HPA) axis was evaluated by detecting the serum corticosterone (CORT) concentrations and mRNA expression of corticotrophin-releasing hormone (CRH) in the hypothalamus. The protein expression levels of brain-derived neurotrophic factor (BDNF) and total phosphorylated-ERK1/2 were detected by western blot. The results showed that OG treatment (1.5, 3, or 6 mg/kg) alleviated the depression-like behaviour of rats under CUMS, as indicated by the increased sucrose preference and the decreased immobility in both the FST and TST, although the rearing frequency in the open field test increased only in the group that received the lowest dose (1.5 mg/kg OG). Rats that received OG treatment exhibited reduced serum CORT levels and CRH mRNA expression in the hypothalamus, suggesting that the hyperactivity of the HPA axis in CUMS rats was reversed by OG treatment. Moreover, OG treatment upregulated the protein levels of BDNF and phosphorylated-ERK1/2 in the hippocampus, even above control levels. Our findings suggest that OG improved depressive behaviour in CUMS rats by downregulating HPA axis hyperactivity and increasing BDNF expression and ERK1/2 phosphorylation in the hippocampus.     

Depression-resistant endophenotype in mice overexpressing cannabinoid CB2 receptors

Background and purpose:

The present study evaluated the role of CB₂ receptors in the regulation of depressive-like behaviours. Transgenic mice overexpressing the CB₂ receptor (CB2xP) were challenged with different types of acute and chronic experimental paradigms to evaluate their response in terms of depressive-like behaviours.

Experimental approach:

Tail suspension test (TST), novelty-suppressed feeding test (NSFT) and unpredictable chronic mild stress tests (CMS) were carried out in CB2xP mice. Furthermore, acute and chronic antidepressant-like effects of the CB₂ receptor-antagonist AM630 were evaluated by means of the forced swimming test (FST) and CMS, respectively, in wild-type (WT) and CB2xP mice. CB₂ gene expression, brain-derived neurotrophic factor (BDNF) gene and protein expressions were studied in mice exposed to CMS by real-time PCR and immunohistochemistry, respectively.

Key results:

Overexpression of CB₂ receptors resulted in decreased depressive-like behaviours in the TST and NSFT. CMS failed to alter the TST and sucrose consumption in CB2xP mice. In addition, no changes in BDNF gene and protein expression were observed in stressed CB2xP mice. Interestingly, acute administration of AM630 (1 and 3 mg·kg⁻¹, i.p.) exerted antidepressant-like effects on the FST in WT, but not in CB2xP mice. Chronic administration of AM630 for 4 weeks (1 mg·kg⁻¹; twice daily, i.p.) blocked the effects of CMS on TST, sucrose intake, CB₂ receptor gene, BDNF gene and protein expression in WT mice.

Conclusion and implications:

Taken together, these results suggest that increased CB₂ receptor expression significantly reduced depressive-related behaviours and that the CB₂ receptor could be a new potential therapeutic target for depressive-related disorders.     

Antidepressant,antioxidant and neurotrophic properties of the standardized extract of <Emphasis Type="Italic">Cocos nucifera</Emphasis> husk fiber in mice

The plant Cocos nucifera and its derivatives have shown antidepressant-like effects, although its hydroalcoholic extract has not been studied with this end in mind. Therefore, we decided to determine the antidepressant-like effects of the standardized hydroalcoholic extract of Cocos nucifera husk fiber (HECN) as well as oxidative alterations in the prefrontal cortex (PFC), hippocampus (HC) and striatum (ST), and the levels of brain-derived neurotrophic factor (BDNF) in the HC of mice. The extract was characterized based on the content of total polyphenols as well as two phenol compounds—catechin and chlorogenic acid—by HPLC-PDA. Male animals were treated per os (p.o.) for 7 days with distilled water or HECN (50, 100 or 200 mg/kg), or intraperitoneally with vitamin E (Vit E 400 mg/kg). One hour after the last drug administration, the animals were submitted to the open field test, forced swimming test (FST), tail suspension test (TST) and, immediately after the behavioral tests, had their brain removed for neurochemical determinations. The results showed that HECN100 decreased the immobility time in the FST and TST presenting, thus demonstrating an antidepressant-like effect. The administration of HECN decreased malondialdehyde levels in all doses and brain areas studied with the exception of HECN50 in the HC. The administration of HECN also decreased nitrite levels in all doses and brain regions studied. HECN100 also increased the levels of BDNF in HC of mice. In conclusion, we demonstrated that HECN has antidepressant-like properties, probably based on its antioxidant and neurotrophic effects, and is thus relevant for the treatment of depression.     

Antidepressant-like effects of ginsenoside Rg1 are due to activation of the BDNF signalling pathway and neurogenesis in the hippocampus

BACKGROUND AND PURPOSE Ginsenoside Rg1 (Rg1) is one of the major bioactive ingredients of Panax ginseng with little toxicity and has been shown to have neuroprotective effects. In this study, we investigated the antidepressant-like effect of Rg1 in models of depression in mice. EXPERIMENTAL APPROACH The effects of Rg1 were assessed in the forced swimming test (FST) and tail suspension test (TST) in mice. Rg1 was also investigated in the chronic mild stress (CMS) mouse model of depression with imipramine as the positive control. Changes in hippocampal neurogenesis and spine density, the brain-derived neurotrophic factor (BDNF) signalling pathway, and serum corticosterone level after chronic stress and Rg1 treatment were then investigated. The tryptophan hydroxylase inhibitor and the tyrosine kinase B inhibitor were also used to explore the antidepressive mechanisms of Rg1. KEY RESULTS Ginsenoside Rg1 exhibited antidepressant-like activity in the FST and TST in mice without affecting locomotor activity. It was also effective in the CMS model of depression. Furthermore, Rg1 up-regulated the BDNF signalling pathway in the hippocampus and down-regulated serum corticosterone level during the CMS procedure. In addition, Rg1 was able to reverse the decrease in dendritic spine density and hippocampal neurogenesis caused by CMS. However, Rg1 had no discernable effect on the monoaminergic system. CONCLUSIONS AND IMPLICATIONS Our results provide the first evidence that Rg1 has antidepressant activity via activation of the BDNF signalling pathway and up-regulation of hippocampal neurogenesis.     

Galantamine (Reminyl) delays cardiac ventricular repolarization and prolongs the QT interval by blocking the HERG current

Ferulic acid (4-hydroxy-3-methoxycinnamic acid) is a phenolic compound present in several plants with claimed beneficial effects in prevention and treatment of disorders linked to oxidative stress and inflammation. In this study, we aimed to verify the possible antidepressant-like effect of acute oral administration of ferulic acid in the forced swimming test (FST) and tail suspension test (TST) in mice. Additionally, the mechanisms involved in the antidepressant-like action and the effects of the association of ferulic acid with the antidepressants fluoxetine, paroxetine, and sertraline in the TST were investigated. Ferulic acid produced an antidepressant-like effect in the FST and TST (0.01-10 mg/kg, p.o.), without accompanying changes in ambulation. The pretreatment of mice with WAY100635 (0.1 mg/kg, s.c., a selective 5-HT(1A) receptor antagonist) or ketanserin (5 mg/kg, i.p., a 5-HT(2A) receptor antagonist) was able to reverse the anti-immobility effect of ferulic acid (0.01 mg/kg, p.o.) in the TST. The combination of fluoxetine (5 mg/kg, p.o.), paroxetine (0.1 mg/kg, p.o.) or sertraline (1 mg/kg, p.o.) with a sub-effective dose of ferulic acid (0.001 mg/kg, p.o.) produced a synergistic antidepressant-like effect in the TST, without causing hyperlocomotion in the open-field test. Taken together, these results demonstrate that ferulic acid exerts antidepressant-like effect in the FST and TST in mice through modulation of the serotonergic system.     

The nicotinic antagonist mecamylamine has antidepressant-like effects in wild-type but not β2- or α7-nicotinic acetylcholine receptor subunit knockout mice

Rationale Increases in cholinergic transmission are linked to depression in human subjects and animal models. We therefore examined the effect of decreasing nicotinic acetylcholine receptor (nAChR) activity in tests of antidepressant efficacy using C57BL/6J mice.Objectives We determined whether the noncompetitive nAChR antagonist mecamylamine had antidepressant-like effects in the forced swim test (FST) and tail suspension test (TST). These experiments were repeated in mice lacking either the β2- or α7-nAChR subunits to identify the nAChR subunits involved in mediating the antidepressant response to mecamylamine.Materials and methods Adult mice on the C57BL/6J background were acutely administered mecamylamine i.p. 30 min before testing in the FST or TST.Results A dose–response study showed that mecamylamine significantly decreased immobility time in the TST at the 1.0-mg/kg dose but did not alter baseline locomotor activity. The competitive nAChR antagonist dihydro-β-erythroidine, but not the blood–brain barrier impermeant antagonist hexamethonium, also decreased immobility in the TST. One milligram per kilogram of mecamylamine also significantly decreased time immobile in the FST whereas both β2- and α7-knockout mice were insensitive to the effects of mecamylamine in the FST.Conclusions Decreased activity of central nAChRs has antidepressant-like effects in both the TST and FST and these effects are dependent on both β2 and α7 subunits. Therefore, compounds that decrease nAChR activity may be attractive new candidates for development as antidepressants in humans.     

Senegenin exerts anti-depression effect in mice induced by chronic un-predictable mild stress via inhibition of NF-κB regulating NLRP3 signal pathway

Depressive disorder is a kind of affective disturbance disease. Emerging evidence has suggested that inflammation may contribute to the pathologic process of depressive disorder. Senegenin (SEN), a major bioactive constituent in Polygala tenuifolia Willd, has much bioactivity including anti-inflammatory and neuroprotection effects. However, the mechanism of its anti-depressant effect in mice remains unknown. This study aimed to explore the anti-depressant effects of SEN on behavioral changes and inflammatory responses in mice induced by chronic un-predictable mild stress (CUMS). SEN treatment remarkably ameliorated CUMS-induced behavioral abnormalities, such as improving locomotor activity, decreasing immobility time in Tail suspension test (TST) and Forced swimming test (FST), and increasing sucrose intake in Sucrose preference test (SPT). Additionally, SEN improve protein levels of Brain-derived neurotrophic factor (BDNF) and Neurotrophin-3 (NT-3) expression.In response to stress, p65 was activated to promote production of pro-IL-1β, and then cleaved to mature IL-1β by NOD-like receptor protein 3 (NLRP3) inflammasome pathway in hippocampus of CUMS mice. After SEN treatment, protein activation related to NLRP3 inflammasome pathway was down-regulated, which inhibited IL-1β secretion. These results demonstrate that SEN plays an important role in treatment CUMS-induced depression in mice, possibly via suppression of pathway activation associated with NLRP3 inflammasome.     

Sex differences in response to oral amitriptyline in three animal models of depression in C57BL/6J mice

Rationale Knockout and transgenic mice provide a tool for assessing the mechanisms of action of antidepressants. The effectiveness of oral administration of the tricyclic antidepressant amitriptyline (AMI) was assessed in C57BL/6J (B6) mice, a common genetic background on which knockout and transgenic mice are maintained.Objectives We determined whether oral AMI would have antidepressant-like effects in B6 mice and whether these effects varied according to sex, duration of treatment, and the depression model utilized.Methods Male and female B6 mice were administered AMI (200 g/ml) in the drinking water as the sole source of fluid, along with 2% saccharin to increase palatability. Control mice were administered 2% saccharin alone. Mice were assessed for responsiveness to AMI in the tail suspension test (TST), the forced swim test (FST), and the learned helplessness (LH) paradigm.Results In the TST, AMI decreased immobility time regardless of sex or duration of treatment. AMI also decreased immobility time in the FST, but chronic treatment was necessary for full efficacy in both sexes. In the LH paradigm, both subchronic and chronic AMI treatment decreased escape latencies in female mice, but AMI was effective only after chronic treatment in males. The antidepressant-like effects of AMI could not be explained by differences in locomotor activity because activity levels were not altered by antidepressant treatment.Conclusions Overall, oral AMI administration provides a valid model for behavioral assessment of antidepressant-like effects in knockout and transgenic mice maintained on a B6 background, but the effectiveness of oral AMI varies depending on sex, duration of treatment, and the depression model used.     

Involvement of norepinephrine and serotonin system in antidepressant-like effects of hederagenin in the rat model of unpredictable chronic mild stress-induced depression

Abstract

Context: Previous studies from our laboratory indicated that both acute and subchronic administration of Fructus Akebiae (FAE) [the fruit of Akebiae quinata (Thunb.) Decne, (Lardizabalaceae)] produce antidepressant-like effects in animal depressive behavior tests. FAE contains approximately 70% of hederagenin (HG) as its main chemical component.

Objective: This study compared the antidepressant ability of FAE with that of HG in mice and further investigated the antidepressant-like effects and potential mechanisms of HG in rats subjected to unpredictable chronic mild stress (UCMS).

Materials and methods: Mice received FAE (50?mg/kg) and HG (20?mg/kg) once a day via intragastric administration (i.g.) for 3?weeks. The anxiolytic and antidepressant activities of FAE and HG were compared using elevated plus maze (EPM) and behavioral despair tests including tail suspension test (TST) and forced swimming test (FST), respectively. Antidepressant effects of HG (5?mg/kg) were assessed using the UCMS depressive rat model. Moreover, the levels of monoamine neurotransmitters and relevant gene expression in UCMS rats’ hippocampi were determined through high-performance liquid chromatography with electrochemical detection and real-time polymerase chain reaction techniques.

Results: The results of our preliminary screening test suggest that HG at 20?mg/kg, while not FAE at 50?mg/kg, significantly decreased the immobility in both TST and FST compared with the vehicle group when administered chronically; however, there were no significant differences observed between the HG and the FAE group. Chronic administration of HG failed to significantly reverse the altered crossing and rearing behavioral performance, time spent in the open arm and closed entries in the EPM, even if they showed an increased tendency, but HG significantly increased the percent of sucrose preference in the sucrose preference test (SPT) and decreased the immobility time in the FST. HG showed that significant increases of norepinephrine and serotonin levels and exhibited a tendency to increase the expression of 5-hydroxytryptamine (serotonin) 1A receptor mRNA, and to significantly decrease the expression of the mRNA for the serotonin transporter (5-HTT). However, there were no significant differences in the expression of the brain-derived neurotrophic factor.

Conclusion: These findings confirm the antidepressant-like effects of HG in a behavioral despair test and UCMS rat model, which may be associated with monoamine neurotransmitters and 5-HTT mRNA expression.