Role of ginsenoside Rb1 in attenuating depression-like symptoms through astrocytic and microglial complement C3 pathway.

Ginsenoside Rb1, known as gypenoside III, exerts antidepressant-like effects in previous studies. It has also been indicated that ginsenoside Rb1 regulated neuroinflammation via inhibiting NF-κB signaling. According to the evidence that astrocytes can regulate microglia and neuroinflammation by secreting complement C3, the present study aimed to demonstrate the molecular mechanisms underlying ginsenoside Rb1-induced antidepressant-like effects from the astrocytic and microglial complement C3 pathway. The complement C3 mediated mechanism of ginsenoside Rb1 was investigated in mice exposed to chronic restraint stress (CRS). The results showed that ginsenoside Rb1 reversed the depressive-like behaviors in CRS. Treatment with ginsenoside Rb1 reduced both the number of astrocytes and microglia. In addition, ginsenoside Rb1 suppressed TLR4/NF-κB/C3 signaling in the astrocytes of the hippocampus. Furthermore, ginsenoside Rb1 attenuated the contents of synaptic protein including synaptophysin and PSD95 in microglia, suggesting the inhibition of microglia-mediated synaptic elimination caused by CRS. Importantly, ginsenoside Rb1 also maintained the dendritic spines in mice. In conclusion, our results demonstrate that ginsenoside Rb1 produces the antidepressant-like effects by inhibiting astrocyte TLR4/NF-κB/C3 signaling to covert microglia from a pro-inflammatory phenotype (amoeboid) towards an anti-inflammatory phenotype (ramified), which inhibit the synaptic pruning in the hippocampus.

[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 components from Lagotis brachystachya maintain uric acid homeostasis by inhibiting renal TLR4-NLRP3 signaling in hyperuricemic mice.

Lagotis brachystachya Maxim is a herb widely used in traditional Tibetan medicine. Our previous study indicated that total extracts from Lagotis brachystachya could lower uric acid levels. This study aimed to further elucidate the active components (luteolin, luteoloside and apigenin) isolated from Lagotis brachystachya and the underlying mechanism in vitro and in vivo. The results showed that treatment with luteolin and luteoloside reversed the reduction of organic anion transporter 1 (OAT1) levels, while apigenin attenuated the elevation of urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) levels in uric acid-treated HK-2 cells, which was consistent with the finding in the kidneys of potassium oxonate (PO)-induced mice. On the other hand, hepatic xanthine oxidase activity was inhibited by the components. In addition, all of these active components improved the morphology of the kidney in hyperuricemic mice. Moreover, molecular docking showed that luteolin, luteoloside and apigenin could bind Toll-like receptor 4 (TLR4) and NLR family pyrin domain containing 3 (NLRP3). Congruently, western blot analysis showed that the components inhibited TLR4/myeloid differentiation primary response 88 (MyD88)/NLRP3 signaling. In conclusion, these results indicated that luteolin, luteoloside and apigenin could attenuate hyperuricemia by decreasing the production and increasing the excretion of uric acid, which were mediated by inhibiting inflammatory signaling pathways.

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.

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.

Circadian variations in behaviors, BDNF and cell proliferation in depressive mice.

Neurotrophic factors are well-known to be involved in the pathophysiology of depression and treatment of antidepressants. Brain-derived neurotrophic factor (BDNF), one of the most widely distributed and the most highly studied neurotrophic factors, has been demonstrated to play an important role in the pathophysiology of depression and the mechanism of antidepressants. According to the previous studies, we found that animal tissues were dissected for BDNF measurement mainly in daytime. Considering the circadian rhythm of BDNF expression, our present study evaluated the circadian variations in behaviors, serum corticosterone concentrations, hippocampal BDNF expression and neuronal cell proliferation in mice exposed to chronic mild stress (CMS), one of the most widely used depression-like animal models. Our results provided the first evidence that the difference of BDNF expression and neuronal cell proliferation between CMS and control mice underwent an oscillation related to the circadian variations (maximum at 20:00 h, minimum at 12:00 h or 16:00 h), while the difference of sucrose preference and first feeding latency was not affected by circadian rhythm. This oscillation difference was attributed to the relative constant BDNF expression and cell proliferation in CMS mice and the fluctuating BDNF expression and cell proliferation in control mice. CMS exposure might destroy the circadian rhythm of BDNF expression and cell proliferation in hippocampus of normal individual. Our present study suggests that animal decapitation at 20:00 h is the best time for BDNF-related measurement in CMS experiment, since the difference reaches the maximum.

Hepatoprotective effect of ethanol extract from Berchemia lineate against CCl4-induced acute hepatotoxicity in mice.

CONTEXT: The roots of Berchemia lineate (L.) DC. (Rhamnaceae) have been long used as a remedy for the treatment of some diseases in Guangxi Province, China. OBJECTIVE: The present study investigates the hepatoprotective effect of Berchemia lineate ethanol extract (BELE) on CCl4-induced acute liver damage in mice. MATERIALS AND METHODS: Effect of BELE administrated for 7 consecutive days was evaluated in mice by the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (TBIL), albulin (ALB), globulin (GLB), and total protein (TP) levels, as well as liver superoxide dismutase (SOD) activity and malondialdehyde (MDA) level. Moreover, histopathological examinations were also taken. RESULTS: Compared with the model group, administration of 400 mg/kg BELE for 7 d in mice significantly decreased the serum ALT (56.25 U/L), AST (297.67 U/L), ALP (188.20 U/L), and TBIL (17.90 mol/L), along with the elevation of TP (64.67 g/L). In addition, BELE (100, 200, and 400 mg/kg, i.g.) treated mice recorded a dose-dependent increment of SOD (291.17, 310.32, and 325.67 U/mg prot) and reduction of MDA (7.27, 6.77, and 5.33 nmol/mg prot) levels. Histopathological examinations also confirmed that BELE can ameliorate CCl4-induced liver injuries, characterized by extensive hepatocellular degeneration/necrosis, inflammatory cell infiltration, congestion, and sinusoidal dilatation. DISCUSSION AND CONCLUSION: The results indicated that BELE possessed remarkable protective effect against acute hepatotoxicity and oxidative injuries induced by CCl4, and that the hepatoprotective effects of BELE may be due to both the inhibition of lipid peroxidation and the increase of antioxidant activity.

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.

Comprehensive biochemical analysis and nutritional evaluation of fatty acid and amino acid profiles in eight seahorse species (Hippocampus spp.).

Seahorses are increasingly recognized for their nutritional potential, which underscores the necessity for comprehensive biochemical analyses. This study aims to investigate the fatty acid and amino acid compositions of eight seahorse species, including both genders of Hippocampus trimaculatus, Hippocampus kelloggi, Hippocampus abdominalis, and Hippocampus erectus, to evaluate their nutritional value. We employed Gas Chromatography-Mass Spectrometry (GC-MS) and High-Performance Liquid Chromatography (HPLC) to analyze the fatty acid and amino acid profiles of the seahorse species. GC-MS was used to detect 34 fatty acid methyl esters, while HPLC provided detailed amino acid profiles. GC-MS analysis demonstrated high precision with relative standard deviations (RSDs) generally below 2.53 %, satisfactory repeatability (RSDs from 6.55 % to 8.73 %), and stability (RSDs below 2.82 %). Recovery rates for major fatty acids ranged from 98.73 % to 109.12 %. HPLC analysis showed strong separation of amino acid profiles with theoretical plate numbers exceeding 5000. Precision tests yielded RSDs below 1.23 %, with reproducibility and stability tests showing RSDs below 2.73 % and 2.86 %, respectively. Amino acid recovery rates ranged from 97.58 % to 104.66 %. Nutritional analysis revealed significant variations in fatty acid content among the species. Female H. erectus showed higher levels of hexadecanoic acid and saturated fatty acids, while male H. abdominalis had lower concentrations of n-3 full cis 4,7,10,13,16,19-docosahexaenoic acid (DHA). Total lipid yields varied from 3.2491 % to 12.3175 %, with major fatty acids constituting 17.9717 %-74.6962 % of total lipids. In conclusion, this study provides essential insights into the fatty acid and amino acid composition of seahorses, supporting their potential as valuable dietary supplements. The differences between genders in specific fatty acids suggest a nuanced nutritional profile that could be exploited for targeted dietary applications. Further research is needed to explore the seasonal and environmental variations affecting seahorse biochemical composition.

Inhibition of colon C5a/C5a receptor signalling pathway confers protection against LPS-induced acute kidney injury via gut microbiota-kidney axis.

Acute kidney injury (AKI) is a critical condition often associated with systemic inflammation and dysregulated gut microbiota. This study aimed to investigate the effects of the C5a receptor antagonist W54011 on lipopolysaccharide (LPS)-induced AKI, focusing on the colon's C5a/C5a receptor pathway, intestinal barrier integrity, and gut microbiota. Our findings demonstrate that W54011 effectively ameliorated kidney injury in the LPS-induced AKI model by selectively inhibiting the colon's C5a/C5a receptor signalling pathway. Additionally, C5a receptor blockade resulted in the inhibition of colonic inflammation and the reconstruction of the intestinal mucosal barrier. Furthermore, W54011 administration significantly impacted the composition and stability of the gut microbiota, restoring the abundance of dominant bacteria to levels observed in the normal state of the intestinal flora and reducing the abundance of potentially harmful bacterial groups. In conclusion, W54011 alleviates LPS-induced AKI by modulating the interplay between the colon, gut microbiota, and kidneys. It preserves the integrity of the intestinal barrier and reinstates gut microbiota, thereby mitigating AKI symptoms. These findings suggest that targeting the colon and gut microbiota could be a promising therapeutic strategy for AKI treatment.

Gut microbiota mediated inflammation, neuroendocrine and neurotrophic functions involved in the antidepressant-like effects of diosgenin in chronic restraint stress.

BACKGROUND: Diosgenin is a well-known steroid saponin possessing neuroprotective activities. However, it is unknown whether diosgenin could alleviate depression-like symptoms. METHODS: The antidepressant-like effect of diosgenin was investigated in mice induced by chronic restraint stress. The effects of diosgenin on behaviors, inflammation, neuroendocrine, neurotrophic function, and gut microbiota were evaluated. RESULTS: The results showed that diosgenin alleviated the depressive-like behaviors in mice. In addition, diosgenin was found to reduce serum concentrations of proinflammatory cytokines and the activity of the hypothalamic-pituitary-adrenal (HPA) axis. Besides, diosgenin could activate hippocampal brain-derived neurotrophic factor (BDNF)/TrkB/ERK/CREB signaling pathway and improve the expression of postsynaptic protein PSD95. Meanwhile, the neurogenesis which was inhibited by chronic restraint stress, was totally reversed by diosgenin. Moreover, diosgenin increased the abundance of phylum Firmicutes and the genus Lactobacillus in stressed mice. The results further showed that diosgenin caused a strong correlation between gut microbiota composition and inflammation, the HPA axis activity, or hippocampus neurotrophic function. LIMITATIONS: Only male mice were used for evaluation in the present study, which limits the understanding of effects of diosgenin on the both sexes. In addition, the results only indicate microbiota at the phylum or genus mediate the regulation of neuroinflammation, neuroendocrine, and neurotrophic function, but does not elucidate how microbiota modulate the systems via their primary or secondary metabolites. CONCLUSIONS: The present study shows that diosgenin exerts the antidepressant activity, which is associated with the enhancement of neurotrophic function and the inhibition of inflammatory and neuroendocrine activities via the regulation of gut microbiota.

Yamogenin Exhibits Antidepressant-like Effects via Inhibition of ER Stress and Microglial Activation in LPS-Induced Mice.

Depression is a multifaceted psychiatric disorder that affects a significant number of individuals worldwide, and its pathophysiology encompasses a variety of mechanisms, including the induction of endoplasmic reticulum (ER) stress, which has been correlated with depressive-like behaviors in animal models. Yamogenin, a bioactive compound derived from traditional Chinese medicine Dioscorea species, possesses diverse pharmacological properties. This investigation aimed to explore the antidepressant-like effects of yamogenin and the underlying mechanisms involved. By utilizing a murine model of lipopolysaccharide (LPS)-induced depressive-like behavior, we demonstrated that yamogenin enhanced sucrose preference and reduced immobility time in the forced swimming test. These effects were observed alongside the attenuation of ER stress through modulation of the PERK/eIF2α/ATF4/CHOP signaling pathway in the prefrontal cortex. Moreover, yamogenin augmented the expression of the antiapoptotic protein Bcl-2 while diminishing the expression of the proapoptotic protein caspase-3. Additionally, yamogenin exhibited inhibitory effects on microglial activation but did not elicit the promotion of brain-derived neurotrophic factor (BDNF) signaling. Collectively, our findings propose that yamogenin exerts antidepressant-like effects in LPS-induced mice by inhibiting ER stress and microglial activation. This study contributes novel insights into the potential utilization of yamogenin as a natural antidepressant agent.

Inhibition of NLRP3 attenuates sodium dextran sulfate-induced inflammatory bowel disease through gut microbiota regulation.

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic, life-threatening inflammatory disease of gastrointestinal tissue characterized by inflammation of the gut. Recent studies have shown that gut microbiota is involved in the pathophysiology of IBD. However, it is unknown whether direct inhibition of NLR family pyrin domain containing 3 (NLRP3) inflammasome regulates IBD and alters gut microbiota. METHODS: Here, the NLRP3 expression was evaluated in the colon of IBD subjects. Then, we investigated the effects of NLRP3 inhibition by MCC950 on the gut microbiota and IBD-like symptoms induced by dextran sulfate sodium (DSS). RESULTS: Firstly, NLRP3 and IL-1ß levels were increased in patients with IBD as compared with healthy individuals. Then, the animal experiment showed that NLRP3 inhibition by MCC950 significantly attenuated IBD-like symptoms such as diarrhea and colonic inflammation in DSS-induced mice. In addition, NLRP3 inhibition inhibited NLRP3/ASC/caspase-1/IL-1ß signaling pathway in the colon, which was over-activated by DSS. Furthermore, MCC950 increased the abundance of phylum Firmicutes, decreased the abundance of phylum Bacteroidetes, and increased the Firmicutes/Bacteroidetes ratio, indicating that the inhibition of NLRP3 inflammasome could regulate the abundance of intestinal flora. According to correlation analysis, NLRP3 might produce its functional role in the regulation of oxidation indicators by changing the gut microbiota composition, especially the phylum Bacteroidota, genus Lactobacillus and species Lactobacillus reuteri. CONCLUSIONS: This study suggests that NLRP3 inflammasome inhibition attenuates IBD-like symptoms by regulating gut microbiota, and provides a basis for the clinical application of NLRP3 as a target for the treatment of IBD.

Hypouricemic effect of the methanol extract from Prunus mume fruit in mice.

CONTEXT: The fruit of the Prunus mume Sieb. et Zucc (Rosaceae) is used as a health food or medicinal material in traditional herb medicine for a long time in Eastern Asian countries. OBJECTIVE: Our present study investigated the hypouricemic effect of the methanol extract from P. mume fruit (MPMF) in mice with potassium oxonate-induced hyperuremia. MATERIALS AND METHODS: Effect of MPMF (35, 70 and 140 mg/kg, p.o.) administrated for 7 days on the serum, liver, urinary uric acid levels and liver xanthine oxidase (XO) activity were assessed in mice. RESULTS: Hyperuricemic mice induced by potassium oxonate demonstrated an elevation in serum and liver uric acid levels (11.0 mg/dL and 0.52 mg/g tissue) and a reduction in urinary uric acid levels (49.9 mg/dL). Oral administration of 140 mg/kg MPMF for 7 days reversed the abnormalities in serum, liver and urinary uric acid levels (7.1 mg/dL, 0.37 mg/g tissue and 69.7 mg/dL, respectively). In addition, 70 and 140 mg/kg MPMF (3.1 and 2.9 nmol/min per mg protein) inhibited liver XO activity compared with hyperuricemic mice (3.9 nmol/min per mg protein). DISCUSSION AND CONCLUSION: The results indicated that the beneficial hypouricaemic effect of MPMF may be mediated, at least in part, by inhibiting XO activity in the liver. Our study suggests that P. mume and its extracts may have a considerable potential for development as an anti-gout agent for clinical application.

Gypenoside XVII, an Active Ingredient from Gynostemma Pentaphyllum, Inhibits C3aR-Associated Synaptic Pruning in Stressed Mice.

Gynostemma pentaphyllum is a herbal medicine widely used in Asian countries, and its saponin extracts have been shown to possess potent anti-inflammatory effects. Gypenoside XVII, an active ingredient isolated from Gynostemma pentaphyllum, has been found to alleviate the inflammation induced by LPS in the BV2 microglia, according to our preliminary study. This study aims to evaluate whether Gypenoside XVII could attenuate depression-like symptoms in vivo and tries to demonstrate the involvement of the complement regulation in its antidepressant-like effect. The results showed that Gypenoside XVII significantly attenuated depression-like behaviors in the forced swimming test, tail suspension test and sucrose preference test. It also alleviated the acute stress-induced hyperactivity of serum corticosterone levels. Additionally, Gypenoside XVII significantly inhibited the activation of microglia and the expression of C3 in mice exposed to chronic unpredictable mild stress (CUMS). Meanwhile, the activation of C3aR/STAT3 signaling and the expression of proinflammatory cytokines was reversed by Gypenoside XVII. Moreover, CUMS induced excessive synaptic pruning by activating microglia, while Gypenoside XVII restored it in the prefrontal cortex. Our data demonstrated that Gypenoside XVII, the active ingredient of Gynostemma pentaphyllum, produced the antidepressant-like effects in mice, which was mediated by the inhibition of complement C3/C3aR/STAT3/cytokine signaling in the prefrontal cortex.

IL-1R/C3aR signaling regulates synaptic pruning in the prefrontal cortex of depression.

BACKGROUND: Major depressive disorder is characterized by not only monoamine neurotransmitters deficiencies but also persistent neuroinflammation. The complement system is an attractive therapeutic target for various inflammation-related diseases due to its early activation in inflammatory processes. RESULTS: In the present study, the dynamic alteration of complement C3 and its receptor C3aR during the occurrence of depression and the mechanism of astrocyte-microglia IL-1R/C3/C3aR on synaptic pruning were investigated. The proteomic analysis firstly showed that chronic stress caused an elevation of C3. GO analysis indicated that complement system-mediated synaptic pruning signaling was involved in depression. The dynamic observation indicated that C3/C3aR was activated in the early onset and throughout the course of depression induced by lipopolysaccharide (LPS) and chronic stress. In contrast, C3aR blockade inhibited the hyperactivation of microglial APT2/DHHC7 palmitoylation cycle, which mediated the translocation of STAT3 and the expression of proinflammatory cytokines. Meanwhile, C3aR blockade also attenuated the synaptic pruning and enhanced the synaptogenesis in the prefrontal cortex of mice. Moreover, the blockade of IL-1R/NF-κB signaling pathway reduced the release of C3 from astrocyte. CONCLUSIONS: The current study demonstrates that astrocyte-microglia IL-1R/C3/C3aR activation causes the abnormal synaptic pruning in depression, and suggests that the activation of complement C3/C3aR may be particularly helpful in predicting the onset stage of depression.

Inhibition of Microglial NLRP3 with MCC950 Attenuates Microglial Morphology and NLRP3/Caspase-1/IL-1ß Signaling In Stress-induced Mice.

Major depressive disorder is characterized by the deficiencies of monoamine neurotransmitters, neurotrophic factors and persistent neuroinflammation. Microglial activation has been associated with neuroinflammation-related mental diseases, accompanied by NLR family pyrin domain containing 3 (NLRP3) inflammasome. Here, we investigated the effect of NLRP3 inhibition by its small molecular inhibitor MCC950 on inflammatory activity and depressive-like mice induced by chronic unpredictable mild stress (CUMS), followed by the behavioral tests including sucrose preference test and forced swimming test. NLRP3/caspase-1/IL-1ß signaling and microglial morphology in the prefrontal cortex were measured. The results showed that CUMS caused a decrease in sucrose preference and an increase in immobility time, which were reversed by NLRP3 inhibitor MCC950. In addition, NLRP3 inhibition decreased the number of microglia and changed the activated state of microglia to a resting state by morphology 3D reconstruction. Moreover, NLRP3 inhibition inactivated NLRP3/caspase-1/IL-1ß signaling in the prefrontal cortex. The results from immunofluorescence demonstrated that NLRP3 and IL-1ß expression was decreased in microglia in response to MCC950 treatment. Accordingly, proinflammatory cytokines were also decreased by NLRP3 inhibition. In conclusion, this study demonstrates that microglial NLRP3 inhibition prevents stress-induced neuroinflammation in the prefrontal cortex and suggests that microglial NLRP3 could be one of the potential therapeutic targets for depression treatment.

CY-09 Alleviates the Depression-like Behaviors via Inhibiting NLRP3 Inflammasome-Mediated Neuroinflammation in Lipopolysaccharide-Induced Mice.

Depression is a serious mental illness, mainly characterized as large mood swings and sleep, diet, and cognitive function disorders. NLPR3, one of the inflammasomes that can be activated by a variety of stimuli to promote the maturation and secretion of pro-inflammatory cytokines, has been considered to be involved in the pathophysiology of depression. In this study, the putative role of CY-09, a selective and direct inhibitor of NLRP3, was evaluated in the lipopolysaccharide (LPS)-induced mice. The results of the study indicated that CY-09 significantly decreased the levels of NLRP3 in the hippocampus of LPS-induced mice. In addition, CY-09 increased the sucrose preference and shortened the immobility time in LPS-induced mice, suggesting the antidepressant-like effects of inhibiting NLRP3 inflammasome. Biochemical analysis showed that LPS significantly activated the NLRP3/ASC/cytokine signaling pathway and caused microglial activation, while CY-09 prevented the changes. Moreover, CY-09 increased the brain-derived neurotrophic factor (BDNF) only in microglia but not in the whole hippocampus. Meanwhile, CY-09 did not promote neurogenesis in the hippocampus of LPS mice. In conclusion, the results of the study showed that the antidepressant-like effects of NLRP3 inhibitor CY-09 were mediated by alleviating neuroinflammation in microglia and independent of the neurotrophic function in the hippocampus.

Lagotis brachystachya maxim attenuates chronic alcoholic liver injury combined with gouty arthritis in rats via its anti-inflammatory activity.

Lagotis brachystachya Maxim, a common herb in Tibetan medicine, is mainly used to treat pneumonia, hepatitis, yellow water disease (gouty arthritis). Since long-term heavy drinking is also a risk factor for gouty arthritis, the present study aimed to evaluate the underlying protective role and mechanism of extracts of Lagotis brachystachya (ELB) in chronic alcoholic liver injury combined with gouty arthritis. The rat chronic alcoholic liver injury combined with gouty arthritis model was established by long-term alcohol consumption and monosodium urate (MSU) injection. The therapeutical action of ELB was then evaluated by biochemical measurement, histopathological examination, ankle swelling assessment, and protein detection. According to biochemical measurements and histopathological evaluation, ELB could alleviate the symptoms of alcoholic liver injury combined with gouty arthritis. In addition, chronic alcohol consumption and MSU activated inflammatory-related signaling such as TLR4/MyD88/NF-κB, NLRP3, and JAK2/STAT3 pathways in the liver and synovial tissues, while ELB significantly inhibited the activation of the inflammatory signaling pathway. In conclusion, ELB is protective in rats with chronic alcoholic liver injury and gouty arthritis, possibly mediated by the inhibition of TLR4/MyD88/NF-κB, NLRP3, and JAK2-STAT3 signaling pathways in both the hepatic and synovial tissues.