Flavopiridol inhibits oocyte maturation, reduces oocyte quality and blocks cumulus cell function.

Flavopiridol (FP) is a plant-derived flavonoidis and used to treat cancers, fungal infections and inflammation-related diseases. However, it is not clear whether it has side effects on the female reproductive system. In this study, we aimed to investigate the toxic effects and potential underlying mechanisms of FP on oocyte maturation and cumulus cell expansion in mice. Cumulus-oocyte complexes (COCs) were cultured in vitro with FP of gradient concentration (50-1000nM), according to the plasma concentration of FP in the clinical trial. The maturation rate and cumulus expansion index of oocytes were counted and studied by immunofluorescence staining, qRT-PCR, oocyte chromosome preparation and so on. The results showed that the FP-exposed COCs inhibited the oocyte maturation and cumulus cell expansion, leading to cell apoptosis in a dose dependent way. Oocytes exposed to 500nM FP showed abnormalities in the spindle structure and chromosome arrangement, ultimately leading to the oocyte maturation arrest and aneuploidy. This may be due to the excessive oxidative stress caused by mitochondrial membrane potential damage and mislocalization. Therefore, when FP is used for cancer treatment, its side effects on the female reproductive system should be seriously considered.

[Chemical constituents from Cinnamomi Ramulus decoction].

Six compounds were isolated from the ethyl acetate extracts of Cinnamomi Ramulus decoction by RP-18, silica gel, Sephadex LH-20 column chromatography, together with prep-HPLC methods. Based on HR-ESI-MS, MS, 1D and 2D NMR spectral analyses, the structures of the six compounds were identified as 4,5,10,11-tetrahydroxybisabol-7-ene(1), 4,5,10,11-tetrahydroxybisabolin(2), 1-phenyl-1,2,3-glycerol(3),(+)-lyoniresinol(4), benzoic acid(5), and decumbic acid(6). Compound 1 was a new bisabolene-type sesquiterpene, and compounds 2 and 3 were isolated from the Cinnamomi Ramulus for the first time. Moreover, the bisabolene-type sesquiterpene(2) was assayed for its anti-inflammatory activity and cytotoxicity to human pancreatic cancer cells(PANC-1 cells). RESULTS:: showed that compound 2 exhibited an inhibitory rate of 32.9% on nitric oxide(NO) at a dose of 40 µmol·L~(-1) and a proliferation inhibition rate of 14.5% against PANC-1 cells at a dose of 20 µmol·L~(-1). It did not demonstrate significant activity.

Active Flavonoids From Lagotis brachystachya Attenuate Monosodium Urate-Induced Gouty Arthritis via Inhibiting TLR4/MyD88/NF-κB Pathway and NLRP3 Expression.

Lagotis brachystachya Maxim is a characteristic herb commonly used in Tibetan medicine. Tibetan medicine records it as an important medicine for the clinical treatment of "Yellow Water Disease," the symptoms of which are similar to that of arthritis. Our previous study showed that the flavonoid fraction extracted from L. brachystachya could attenuate hyperuricemia. However, the effects of the active flavonoids on gouty arthritis remain elusive, and the underlying mechanism is not understood. In the present study, the effects of the active flavonoids were evaluated in rats or Raw264.7 cells with gouty arthritis induced by monosodium urate (MSU) crystal, followed by the detection of TLR4, MyD88, pNF-κB, and NLR family pyrin domain-containing 3 (NLRP3) expression. The swelling of the ankle joint induced by MSU crystal began to be relieved 6 h post the administration with the active flavonoids. In addition, the active flavonoids not only alleviated MSU crystal-induced inflammation in synovial tissues by histopathological examination but also reduced tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1ß) levels in the joint tissue fluid of MSU crystal-induced rats. Furthermore, Western blot analysis indicated that the active flavonoids reduced the production of these cytokines by inhibiting the TLR4/MyD88/NF-κB pathway and decreasing NLRP3 expression in synovial tissues of rats. More importantly, the inhibition of TLR4/MyD88/NF-κB pathway and NLRP3 expression was also confirmed in MSU-induced Raw264.7 cells. In conclusion, these results indicated that the active flavonoids from L. brachystachya could effectively attenuate gouty arthritis induced by MSU crystal through the TLR4/MyD88/NF-κB pathway and NLRP3 expression in vivo and in vitro, suggesting several potential candidates for the treatment of gouty arthritis.

Antidepressant-like effect of Ganoderma lucidum spore polysaccharide-peptide mediated by upregulation of prefrontal cortex brain-derived neurotrophic factor.

A 28-kDa polysaccharide-peptide (PGL) with antidepressant-like activities was isolated from spores of the mushroom Ganoderma lucidum. It was unadsorbed on DEAE-cellulose. Its internal amino acid sequences manifested pronounced similarity with proteins from the mushrooms Lentinula edodes and Agaricus bisporus. The monosaccharides present in 28-kDa PGL comprised predominantly of glucose (over 90%) and much fewer galactose, mannose residues, and other residues. PGL manifested antidepressant-like activities as follows. It enhanced viability and DNA content in corticosterone-injured PC12 cells(a cell line derived from a pheochromocytoma of the rat adrenal medulla with an embryonic origin from the neural crest containing a mixture of neuroblastic cells and eosinophilic cells) and reduced LDH release. A single acute PGL treatment shortened the duration of immobility of mice in both tail suspension and forced swimming tests. PGL treatment enhanced sucrose preference and shortened the duration of immobility in mice exposed to chronic unpredictable mild stress (CUMS). Chronic PGL treatment reversed the decline in mouse brain serotonin and norepinephrine levels but did not affect dopamine levels. PGL decreased serum corticosterone levels and increased BDNF mRNA and protein levels and increased synapsin I and PSD95 levels in the prefrontal cortex. This effect was completely blocked by pretreatment with the BDNF antagonist K252a, indicating that PGL increased synaptic proteins in a BDNF-dependent manner.Key points• An antidepressive polysaccharide-peptide PGL was isolated from G. lucidum spores.• PGL protected PC12 nerve cells from the toxicity of corticosterone.• PGL upregulated BDNF expression and influenced key factors in the prefrontal cortex.

Berberine administrated with different routes attenuates inhaled LPS-induced acute respiratory distress syndrome through TLR4/NF-κB and JAK2/STAT3 inhibition.

Accumulating evidence showed that berberine possessed the anti-inflammatory action in various diseases caused by inflammation. However, it was still unclear whether both inhalation and injection with berberine produced pulmonary protective role in acute respiratory distress syndrome (ARDS). This study was aimed to evaluate the effects of both administration routes including inhalation and injection with berberine in ARDS induced by lipopolysaccharide (LPS) inhalation. Histopathological examination and weight of lung were evaluated. Phosphorylation of NF-κB, JAK2 and STAT3 were measured to assess the activity of inflammation related signaling pathways. Proinflammatory cytokines including interleukin (IL)-1ß and tumor necrosis factor (TNF)-α in the bronchoalveolar lavage fluid (BALF) and serum were also detected. The results showed that LPS caused the lung injury, while both administration routes with berberine attenuated the injury and improved the pulmonary morphology. In addition, the primary TLR4/NF-κB and secondary JAK2/STAT3 signaling pathways which were activated by LPS in lung were totally inhibited by berberine administration. Moreover, proinflammatory cytokines in both BALF and serum were decreased by berberine. Considering that molecular docking simulation indicated that berberine could bind with TLR4, the present suggested that the inhibition of the inflammation related TLR4/NF-κB and JAK2/STAT3 signaling pathways might be involved in the pulmonary protective effect of berberine in LPS-induced ARDS.

Curcumin attenuates cognitive impairment by enhancing autophagy in chemotherapy.

Cisplatin, a commonly used chemotherapy drug, can increase the survival rate of cancer patients. However, it often causes various side effects, including neuronal deficit-induced cognitive impairment. Considering that curcumin is effective in neuronal protection, the action of curcumin on cognitive improvement was evaluated in cisplatin-treated C57BL/6 mice in the present study. Our results first showed that curcumin restored impaired cognitive behaviors. Consistent with this, neurogenesis and synaptogenesis were improved by curcumin. In addition, cisplatin-induced dysfunction of apoptosis-related proteins was partly reversed by curcumin. Moreover, cisplatin-induced autophagy was enhanced by curcumin. Our results also indicated that cisplatin induced autophagy through the endoplasmic reticulum (ER) stress-mediated ATF4-Akt-mTOR signaling pathway. Curcumin activated AMPK-JNK signaling, which mediated both mTOR inhibition and Bcl-2 upregulation and in turn enhanced autophagy and suppressed apoptosis, respectively. In contrast, pretreatment with the autophagy inhibitor 3-methyladenine (3-MA) completely abolished the effects of curcumin on cognitive improvement and improved neurogenesis, synaptogenesis and autophagy. Our results show that cognitive improvement induced by curcumin during chemotherapy is mediated by the enhancement of hippocampal autophagy.

Macranthol attenuates lipopolysaccharide-induced depressive-like behaviors by inhibiting neuroinflammation in prefrontal cortex.

Macranthol is a lignans natural product isolated from Illicium dunnianum Tutch. Our previous studies have shown that BDNF dependent signaling pathway activation was involved in the antidepressant-like effects of macranthol. However, it is not clear whether neuro-inflammation suppression is involved in the effects of macranthol. Therefore, the aim of this present study was to determine whether macranthol affected the neuro-inflammation system in lipopolysaccharide (LPS)-induced mice by measuring pro-inflammatory cytokines and CD11b. Macranthol was orally administrated for successive seven days before a single LPS injection. The behavioral evaluation showed that macranthol prevented LPS-induced depressive-like deficits both in sucrose preference test and forced swimming test. The elevation of serum and prefrontal cortex pro-inflammatory cytokines including interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) was decreased by macranthol pretreatment. In addition, LPS induced the elevation of CD11b in the prefrontal cortex, which was also inhibited by macranthol. Last but not the least, the immunofluorescence found that the number of positive iba-1 cells was also decreased by macranthol. These findings suggest that macranthol could alleviate depressive-like behaviors in mice induced by LPS that are mediated, at least by suppressing microglia-related neuro-inflammation in the prefrontal cortex.

The antidepressant-like effects of Chaihu Shugan San: Dependent on the hippocampal BDNF-TrkB-ERK/Akt signaling activation in perimenopausal depression-like rats.

Chaihu Shugan San (CSS), a traditional Chinese medicine formula, has been used to treat depression for hundreds of years. Recently, the antidepressant-like mechanism of CSS has been increasingly evaluated and demonstrated. However, there are few studies focused on the involvement of the neurotrophic system in mediating the antidepressant-like effects of CSS. Considering the high prevalence of perimenopausal depression around the world, the goal of the present study was to determine whether brain-derived neurotrophic factor (BDNF) signaling is required for the antidepressant-like effects of CSS in perimenopausal depressive-like rats. The results indicate that CSS reverses depressive-like behaviors and attenuates the downregulation of BDNF in the hippocampus of perimenopausal rats exposed to chronic unpredictable mild stress (CUMS). We found that the TrkB antagonist K252 not only blocks the effects of CSS on behavioral improvement but also abolishes the activation of CSS in BDNF-TrkB signaling. As a result, the downstream targets of BDNF signaling, such as the ERK and Akt pathways, are significantly inhibited by K252a. Furthermore, CSS increases hippocampal neurogenesis, while K252a fully prevents this action. In conclusion, the present results demonstrate that the activation of the hippocampal BDNF-TrkB-ERK/Akt signaling pathway is required for the antidepressant-like effects of CSS on the depressive-like state during perimenopause. Additionally, this study also demonstrates that neurogenesis is required for the effects of antidepressants in aging perimenopausal animals and provides fundamental evidence for the clinical application of CSS.

Magnolol abrogates chronic mild stress-induced depressive-like behaviors by inhibiting neuroinflammation and oxidative stress in the prefrontal cortex of mice.

Magnolol, the main constituent of Magnolia officinalis, has been shown to produce antidepressant-like effect in rodents. Growing evidence shows that neuroinflammation, oxidative stress and neuroendocrine contribute to the pathogenesis of major depression. Here, the aim of this present study was to determine whether magnolol affected these systems in mice exposed to chronic mild stress (CMS). The ameliorative effect of magnolol on depressive-like symptoms was investigated through behavioral tests, including the classical sucrose preference and forced swimming tests. The behavioral evaluation showed that magnolol reversed the depressive-like deficits both in sucrose preference test and forced swimming test. The elevation of prefrontal cortex pro-inflammatory cytokines such as interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) was decreased by magnolol. Consistently, the microglia activation by CMS was also alleviated by magnolol. In addition, the hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis induced by CMS was attenuated by magnolol. Moreover, the increased lipid peroxidation such as malonaldehyde (MDA) and decreased antioxidant defense enzymes including superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) induced by CMS were also reversed by magnolol. These findings suggest that administration of magnolol could alleviate depressive-like behaviors in CMS mice that are mediated by suppressing neuroinflammation and oxidative stress in the prefrontal cortex.

Saikosaponin A attenuates perimenopausal depression-like symptoms by chronic unpredictable mild stress.

Accumulating studies have shown that a traditional Chinese decoction Chaihu-Shugan-San produced the antidepressant-like effects in rodents including in perimenopausal. Previous studies and our preliminary study indicated that saikosaponin A, one of the main constituents of Chaihu-Shugan-San, enhanced brain-derived neurotrophic factor (BDNF) expression in rats. Herein, this study aimed to evaluate the antidepressant-like effects of saikosaponin A in perimenopausal rats exposed to chronic unpredictable mild stress (CUMS). The sucrose preference test, novelty-suppressed feeding test and forced swimming test were performed after administration of saikosaponin A for 4 weeks. Serum corticotrophin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and corticosterone levels, as well as hypothalamus CRH and hippocampal glucocorticoid receptor were measured. In addition, pro-inflammatory cytokines such as interleukin-1beta (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in the hippocampus were detected for evaluation of the neuroinflammation. Further, BDNF levels and its receptor TrkB were also determined. Our results indicated that four-week treatment with saikosaponin A increased sucrose preference, decreased latency to feed in the novelty-suppressed feeding test and reduced the immobility time in the forced swimming test. In addition, saikosaponin A restored the dsyregulation of HPA axis and neuroinflammation in rats exposed to CUMS. Moreover, saikosaponin A promoted BDNF-TrkB signaling in the hippocampus. This study demonstrates that saikosaponin A produced the antidepressant-like effects in rats, which may be mediated by restoration of neuroendocrine, neuroinflammation and neurotrophic systems in the hippocampus during perimenopausal.

Berberine attenuates depressive-like behaviors by suppressing neuro-inflammation in stressed mice.

Berberine, the major constituent alkaloid originally from the famous Chinese herb Huanglian (Coptis chinensis), has been shown to exert antidepressant-like effects in rodents. However, it is still not clear the involvement of neuro-inflammation suppression in the effects of berberine. The purpose of this study was to determine whether berberine affects the neuro-inflammation system in mice induced by chronic unpredictable mild stress (CUMS). Berberine was orally administrated in normal or CUMS mice for successive four weeks. Behavioral evaluation showed that berberine prevented the depressive deficits both in sucrose preference test and novelty-suppressed feeding test. The elevation of hippocampal pro-inflammatory cytokines such as interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), as well as the activation of microglia were decreased by berberine. In addition, chronic berberine treatment inhibited nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway as the phosphorylated proteins of NF-κB, IκB kinase (IKK)α and IKKß in the hippocampus were suppressed after berberine administration. Furthermore, inducible nitric oxide synthase (iNOS), one downstream target of NF-κB signaling pathway was also inhibited by berberine. In conclusion, these findings suggest that administration of berberine could prevent depressive-like behaviors in CUMS mice by suppressing neuro-inflammation in the hippocampus.

Ferulic acid inhibits neuro-inflammation in mice exposed to chronic unpredictable mild stress.

Ferulic acid is a hydroxycinnamic acid that widely presents in plant cell wall components. It has been demonstrated that ferulic acid can attenuate depressive-like behaviors in both forced swimming test and tail suspension test. Considering that depression is an inflammatory related mental disease, our present study was aimed to investigate the role of ferulic acid in the regulation of microglia activation, pro-inflammatory cytokines, nuclear factor kappa B (NF-κB) and nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome in mice exposed to chronic unpredictable mild stress (CUMS). Our results firstly showed that decreased sucrose preference and increased immobility time were completely reversed by administration with ferulic acid and fluoxetine for four weeks. Then, we found that CUMS significantly caused interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) up-regulation, microglia, NF-κB signaling and NLRP3 inflammasome activation in the prefrontal cortex. On the contrary, these activated inflammatory response induced by CUMS were reversed by ferulic acid and fluoxetine as well, suggesting that anti-inflammatory related mechanism was involved in the antidepressant-like effects of ferulic acid in stressed mice.

Antidepressant-like effects of standardized gypenosides: involvement of brain-derived neurotrophic factor signaling in hippocampus.

RATIONALE: Gypenosides have been reported to produce neuroprotective effects and increase monoamine neurotransmitter levels in the brain. OBJECTIVE: Considering that depression is involved in monoamine reduction, this study evaluated the antidepressant-like effects of gypenosides in mice exposed to chronic unpredictable mild stress (CUMS). METHODS: The sucrose preference test and forced swimming test were performed after administration of gypenosides (at 25, 50, or 100 mg/kg) for 4 weeks. Hippocampal brain-derived neurotrophic factor (BDNF) and its downstream targets were analyzed by western blot. Additionally, hippocampal neuronal proliferation was measured by immunohistochemistry. RESULTS: Four-week treatment with fluoxetine (20 mg/kg) and gypenosides (at either 50 or 100 mg/kg) increased sucrose preference and decreased the immobility time in mice exposed to CUMS. In addition, gypenosides (at either 50 or 100 mg/kg) also increased BDNF expression and neuronal proliferation in the hippocampus of CUMS animals. Further, we showed that treating CUMS mice with K252a, which is an inhibitor of the BDNF receptor TrkB, blocked the effects of gypenosides (100 mg/kg), including behavioral improvements, neuronal proliferation, and up-regulation of p-TrkB, p-ERK, and p-Akt proteins. CONCLUSIONS: This study demonstrates that gypenosides exhibit antidepressant-like effects in mice, which may be mediated by activation of the BDNF-ERK/Akt signaling pathway in the hippocampus.

The renal protective effects of Anoectochilus roxburghii polysaccharose on diabetic mice induced by high-fat diet and streptozotocin.

ETHNOPHARMACOLOGICAL RELEVANCE: Anoectochilus roxburghii (Wall.) Lindl. 1832 is an herbal medicine used to treat diabetes in China. Considering that Anoectochilus roxburghii polysaccharose (ARP) is the main constituent of Anoectochilus roxburghii, the present study is aimed to investigate the renal protection of ARP and its possible mechanism in diabetic mice. MATERIALS AND METHODS: Institute of Cancer Research (ICR) mice were induced to diabetes with high-fat diet (HFD) and low-dose streptozotocin (STZ). ARP (100, 300 mg/kg) was orally administrated to diabetic mice once a day for consecutive 15 days. The fasting glucose level, expressions of key proteins of p38 MAP kinase cascade, inflammatory factors, fibronectin (FN) and the activities of matrix metalloproteinases (MMPs) were measured. Furthermore, the histological examination of the separated kidneys was also carried out. RESULTS: Compared with the diabetic mice, ARP administration induced a significant decrease in blood glucose level and improved the body weight of diabetic mice. In addition, ARP inhibited the expression of renal p38 MAP kinase cascade and its downstream inflammatory factors including tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), FN as well as MMP2/9. Moreover, the histological examination showed an apparent reduction of mesangial matrix deposition and damage of microvascular structure after ARP administration. CONCLUSIONS: The protective effects of ARP on diabetic renal damage may be attributed to the inhibition of p38 MAP kinase cascade and then attenuating the inflammatory responses and high glucose-induced renal damage.

Macranthol promotes hippocampal neuronal proliferation in mice via BDNF-TrkB-PI3K/Akt signaling pathway.

Macranthol is a lignans natural product isolated from Illicium dunnianum Tutch. Our previous study has demonstrated that macranthol exerted an antidepressant-like effect in mice, at least in part, by increasing expression of hippocampal brain-derived neurotrophic factor (BDNF) expression. However, the relationship between macranthol and BDNF downstream signaling pathway in the hippocampus remains unknown. The aim of this present study was to explore the mechanism of macranthol-modulated BDNF signaling pathway in a depression-like model of chronic unpredictable mild stress. Our results found that pharmacological inhibition of tropomyosin related kinase B (TrkB) with K252a abolished the improvement of macranthol on sucrose preference and immobility time, and attenuated the stimulatory effect of macranthol on hippocampal BDNF and phospho-Akt. Furthermore, K252a also reversed the improvement of macranthol on hippocampal Bcl-2, caspase-3 expression and hippocampal neuronal cell proliferation. Therefore, our findings verify that macranthol-mediated antidepressant-like action is associated with BDNF-TrkB and downstream activation of PI3K/Akt-Bcl-2/caspase-3 signaling pathway.

Essential oil of Syzygium aromaticum reverses the deficits of stress-induced behaviors and hippocampal p-ERK/p-CREB/brain-derived neurotrophic factor expression.

Syzygium aromaticum has been widely used in traditional medicine. Our study investigated the safety and antidepressant-like effects of the essential oil of S. aromaticum after acute or long-term treatment. Using GC-MS, a total of eight volatile constituents were identified in the essential oil of S. aromaticum. The single LD50 was approximately 4500 mg/kg based on a 24-h acute oral toxicity study. In a long-term repeated toxicity study of this essential oil (100, 200, and 400 mg/kg, p. o.), only 400 mg/kg induced a significant decrease in body weight. In addition, no significant changes in relative organ weights and histopathological analysis were observed in all doses of essential oil-treated mice compared with the control group. Furthermore, acute S. aromaticum essential oil administration by gavage exerted antidepressant-like effects in the forced swimming test (200 mg/kg, p < 0.05) and tail suspension test (100 and 200 mg/kg, p < 0.05). Long-term S. aromaticum essential oil treatment via gavage significantly increased sucrose preference (50 mg/kg, p < 0.05; 100 and 200 mg/kg, p < 0.01) as well as elevated the protein levels of hippocampal p-ERK, p-CREB, and brain-derived neurotrophic factor in mice exposed to chronic unpredictable mild stress. These results confirmed the safety of the essential oil of S. aromaticum and suggested that its potent antidepressant-like property might be attributed to the improvement in the hippocampal pERK1/2-pCREB-BDNF pathway in rats exposed to chronic unpredictable mild stress.

BDNF-ERK-CREB signalling mediates the role of miR-132 in the regulation of the effects of oleanolic acid in male mice.

BACKGROUND: Although previous study has demonstrated that brain-derived neurotrophic factor (BDNF) is involved in the antidepressant-like effect of oleanolic acid, there is little information regarding the details of the molecular mechanism involved in this effect. METHODS: We used a chronic unpredictable mild stress (CUMS) model to test the antidepressant-like effect of oleanolic acid on depressant-like behaviour, miR-132 expression and synaptic protein expression in the male mouse hippocampus. Furthermore, we explored the possible signalling pathways associated with miR-132 expression that mediate the effect of oleanolic acid on neuronal proliferation. RESULTS: The results demonstrated that a 3-week treatment with oleanolic acid ameliorated CUMS-induced anhedonic and anxiogenic behaviours. Furthermore, we found that oleanolic acid led to the BDNF-related phosphorylation and activation of extracellular signal-regulated kinases (ERK) and cyclic adenosine monophosphate response element binding protein (CREB), which was associated with the upregulation of miR-132 and hippocampal neuronal proliferation. Moreover, experiments with an miR-132 antagomir revealed that targeting miR-132 led to inhibition of neuronal proliferation and the postsynaptic density protein 95, but did not affect presynaptic protein synapsin I. LIMITATIONS: Several other stimuli can also induce CREB phosphorylation in the hippocampus. Thus, regulation of miR-132 may not be restricted to neurotrophic signalling. CONCLUSION: Our results show that oleanolic acid induces the upregulation of miR-132, which serves as an important regulator of neurotrophic actions, mainly through the activation of the hippocampal BDNF-ERK-CREB signalling pathways.

Ethanol extracts from Hemerocallis citrina attenuate the upregulation of proinflammatory cytokines and indoleamine 2,3-dioxygenase in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Hemerocallis citrina, a traditional herbal medicine, has been used for the improvement of behavioral and emotional status in Eastern-Asia countries. Previous studies in our laboratory demonstrated that ethanol extracts from Hemerocallis citrina (HCE) enhanced monoamines and brain-derived neurotrophic factor (BDNF) in depression-like model of rodents. MATERIALS AND METHODS: The present study extends earlier works on the role of anti-inflammation in regulating the antidepressant-like actions of HCE in rats exposed to chronic unpredictable mild stress (CUMS). Frontal cortex and hippocampal proinflammatory cytokines levels and indoleamine 2,3-dioxygenase (IDO) activity were measured after 4-week HCE treatment in the CUMS an control rats. RESULTS: Chronic administration of HCE reversed the decreased sucrose preference in sucrose preference test. In addition, we also found that HCE inhibited interleukin-1 beta (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) expression, as well as IDO activity in frontal cortex and hippocampus, which were increased in rats exposed to CUMS. CONCLUSIONS: Combining with our previous studies, our present finding suggests that the anti-inflammatory property of HCE might play a crucial role in its antidepressant-like effect through, at least in part, the restoration or improvement of monoaminergic and neurotrophin systems.

BDNF signaling is necessary for the antidepressant-like effect of naringenin.

Previous studies in our laboratory have demonstrated that naringenin produced antidepressant-like action in tail suspension test (TST). However, the underlying mechanisms involved in neurotrophin system by which naringenin works have not been investigated. The present study extends earlier works on the role of brain-derived neurotrophic factor (BDNF) in regulating the antidepressant-like actions of naringenin in chronic unpredictable mild stress (CUMS). We showed that a 21-day regimen with naringenin reversed the decreased sucrose preference in sucrose preference test (SPT) and the prolonged first feeding latency in novelty-suppressed feeding test (NSFT), without affecting home-cage feeding consumption. In addition, we also found that naringenin promoted BDNF expression in the hippocampus but not in the frontal cortex in both non-stressed and CUMS mice. Moreover, the antidepressant-like effect of naringenin in SPT and NSFT induced by naringenin administration were totally abolished by K252a, an inhibitor of BDNF receptor tropomyosin-related kinase receptor B (TrkB). In conclusion, our findings suggest that the antidepressant-like effect of naringenin may be mediated, at least in part, by the activation of BDNF signaling in the hippocampus.

Essential oil of Perilla frutescens-induced change in hippocampal expression of brain-derived neurotrophic factor in chronic unpredictable mild stress in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Perilla frutescens (Perilla leaf), a traditional Chinese medicinal herb, has been used for centuries to treat various conditions including depression. A previous study of the authors demonstrated that essential oil of Perilla frutescens (EOPF) attenuated the depressive-like behavior in mice. AIM OF THE STUDY: This study was undertaken to explore the dynamic change of behaviors and brain-derived neurotrophic factor (BDNF) expression induced by chronic unpredictable mild stress (CUMS), and improved by EOPF. MATERIALS AND METHODS: Four separate CUMS experimental groups (1-week, 2-week, 3-week and 4-week treatment) were treated with EOPF (3 mg/kg and 6 mg/kg, p.o.) or fluoxetine (20 mg/kg, p.o.), followed by sucrose preference, locomotor activity, immobility and hippocampal BDNF measurement. RESULTS: EOPF, as well as fluoxetine, restored the CUMS-induced decreased sucrose preference and increased immobility time, without affecting body weight gain and locomotor activity. Furthermore, CUMS (3 or 4-week) produced a reduction in both BDNF mRNA and protein expression in the hippocampus, which were ameliorated by EOPF (4-week) and fluoxetine (3 or 4-week) treatment. CONCLUSION: These results presented here show that BDNF is expressed depending on length of CUMS procedure and EOPF administration. And this study might contribute to the underlying reason for the slow onset of antidepressant activity in clinic.