The protective effect of Geniposide on diabetic cognitive impairment through BTK/TLR4/NF-κB pathway

Geniposide ameliorates brain injury in mice with intracerebral hemorrhage by inhibiting NF-κB signaling

BACKGROUND

Neuroinflammation and oxidative stress are critical players in intracerebral hemorrhage (ICH). Geniposide is an active component of Gardenia that has anti-inflammatory effects. This study focused on the roles and mechanisms of geniposide in ICH.

METHODS

ICH was established by injecting collagenase IV into C57BL/6 mice. To determine the functions of geniposide and NF-κB inhibition in ICH model mice, geniposide (1, 25, or 50 mg/kg) or PDTC (a NF-κB inhibitor) was administered. Neurological functions were assessed with the modified neurological severity score (mNSS) test. Hematoxylin and eosin staining were performed to identify pathological changes. IL-1β and TNF-α levels were estimated with ELISA kits. NF-κB p65 localization was determined by immunofluorescence staining. Oxidative stress was analyzed by measuring ROS levels.

RESULTS

Geniposide alleviated cerebral edema and neurological deficits. Geniposide inhibited neuroinflammation and oxidative stress after ICH, and the inhibitory effects were enhanced by NF-κB inhibition. Additionally, geniposide inhibited NF-κB signaling.

CONCLUSION

Geniposide alleviates brain injury by suppressing inflammation and oxidative stress damage in experimental ICH models by inhibiting NF-κB signaling.

Discovery of Ibrutinib-based BTK PROTACs with in vivo anti-inflammatory efficacy by inhibiting NF-κB activation

As a critical upstream regulator of nuclear factor-κB (NF-κB) activation, Bruton's tyrosine kinase (BTK) has been identified to be an effective therapeutic target for the treatment of acute or chronic inflammatory diseases. Herein, we describe the design, synthesis and structure-activity-relationship analysis of a novel series of Ibrutinib-based BTK PROTACs by recruiting Cereblon (CRBN) ligase. Among them, compound 15 was identified as the most potent degrader with a DC50 of 3.18 nM, significantly better than the positive control MT802 (DC50 of 63.31 nM). Compound 15 could also degrade BTK protein in Lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and suppress the mRNA expression and secretion of proinflammatory cytokines such as IL-1β and IL-6 by inhibiting NF-κB activation. Furthermore, compound 15 reduced inflammatory responses in a mouse zymosan-induced peritonitis (ZIP) model. Our findings demonstrated for the first time that targeting BTK degradation by PROTACs might be an alternative option for the treatment of inflammatory disorders, and compound 15 represents one of the most efficient BTK PROTACs (DC50 = 3.18 nM; Dmax = 99.90%; near 100% degradation at 8 h) reported so far and could serve as a lead compound for further investigation as an anti-inflammatory agent.

Pretreatment with geniposide mitigates myocardial ischemia/reperfusion injury by modulating inflammatory response through TLR4/NF-κB pathway

Geniposide (GEN), a medical herb, is known for its therapeutic applications in cardiovascular diseases, though its efficacy in treating myocardial ischemia/reperfusion injury (MI/RI) is yet to be fully elucidated. This study is an endeavor to explore the potential protective mechanism of GEN against MI/RI. To simulate the MI/RI condition, the left anterior descending artery was occluded for 30 min, followed by a reperfusion period of 120 min in a rat model. Three dosages (50, 100, or 150 mg/kg) of GEN were intraperitoneally injected to the Sprague-Dawley rats once a day, for seven days before the ligation of the artery. The rats were categorized into sham group, MI/RI group, and three different dosages GEN-treated groups. As the results showed, the pretreatment with GEN mitigated myocardial injury, reduced infarct volume, inhibited apoptosis, enhanced superoxide dismutase activity, and decreased malondialdehyde and myeloperoxidase activity, as well as serum creatine kinase-MB and lactate dehydrogenase levels. Moreover, GEN ameliorated MI/RI by downregulating protein expression of toll-like receptor 4, myeloid differentiation primary response 88, and p-nuclear factor-κB. In conclusion, the pretreatment of GEN may be considered as a potential therapeutic option for MI/RI.

Neuroprotective effect of salidroside on hippocampal neurons in diabetic mice via PI3K/Akt/GSK-3β signaling pathway

BACKGROUND

Diabetic encephalopathy is manifested by cognitive dysfunction. Salidroside, a nature compound isolated from Rhodiola rosea L, has the effects of anti-inflammatory and antioxidant, hypoglycemic and lipid-lowering, improving insulin resistance, inhibiting cell apoptosis, and protecting neurons. However, the mechanism by which salidroside alleviates neuronal degeneration and improves learning and memory impairment in diabetic mice remains unclear.

OBJECTIVE

To investigate the effects and mechanisms of salidroside on hippocampal neurons in streptozotocin-induced diabetic mice.

MATERIALS AND METHODS

C57BL/6 mice were randomly divided into 4 groups to receive either sham (control group (CON)), diabetes mellitus (diabetes group (DM)), diabetes mellitus + salidroside (salidroside group (DM + SAL)), and diabetes mellitus + salidroside + phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 (diabetes mellitus + salidroside + LY294002 group (DM + SAL + LY294002)). After 12 weeks of diabetes onset, the cognitive behaviors were tested using Morris water maze. The number of hippocampal neurons was detected by Nissl staining. The expressions of PI3K, p-PI3K, Akt, p-Akt, GSK-3β, p-GSK-3β, cleaved caspase-3, caspase-3, Bax, Bcl-2, MAP2, and SYN in the hippocampus were detected by Western blot. Moreover, the expression of MAP2 and SYN in the hippocampus was further confirmed by immunofluorescence staining.

RESULTS

Salidroside increased the time of diabetic mice in the platform quadrant and reduced the escape latency of diabetic mice. Salidroside also increased the expression of p-PI3K, p-Akt, p-GSK-3β, MAP2, SYN, Bcl-2, while suppressed the expression of cleaved caspase-3, caspase3, and Bax in the DM + SAL group compared with the DM group (P < 0.05). The Nissl staining showed that the number of hippocampus neurons in the DM + SAL group was increased with the intact, compact, and regular arrangement, compared with the DM groups (P < 0.05). Interestingly, the protective effects of salidroside on diabetic cognitive dysfunction, hippocampal morphological alterations, and protein expressions were abolished by inhibition of PI3K with LY294002.

CONCLUSIONS

Salidroside exerts neuroprotective properties in diabetic cognitive dysfunction partly via activating the PI3K/Akt/GSK-3β signaling pathway.

Geniposide suppressed OX-LDL-induced osteoblast apoptosis by regulating the NRF2/NF-κB signaling pathway

BACKGROUND

Osteoporosis (OP), due to microarchitectural alterations, is associated with decreased bone mass, declined strength, and increased fracture risk. Increased osteoblast apoptosis contributes to the progression of OP. Natural compounds from herbs provide a rich resource for drug screening. Our previous investigation showed that geniposide (GEN), an effective compound from Eucommia ulmoides, could protect against the pathological development of OP induced by cholesterol accumulation.

METHODS

The rat OP models were duplicated. Dual-energy X-ray absorptiometry, hematoxylin and eosin staining, and immunohistochemistry were used to evaluate bone changes. TUNEL/DAPI staining assays were used for cell apoptosis detection. Protein expression was determined by western blotting assays.

RESULTS

A high-fat diet promoted OP development in vivo, and OX-LDL stimulated osteoblast apoptosis in vitro. GEN exhibited protective activities against OX-LDL-induced osteoblast apoptosis by increasing the NRF2 pathway and decreasing the NF-κB pathway. PDTC, an NF-κB inhibitor, could further promote the biological functions of GEN. In contrast, ML385, an NRF2 inhibitor, might eliminate GEN's protection.

CONCLUSION

GEN suppressed OX-LDL-induced osteoblast apoptosis by regulating the NRF2/NF-κB signaling pathway.

Hippocampal proteins discovery of Panax quinquefolius and Acorus gramineus ameliorating cognitive impairment in diabetic rats

RATIONALE

Early diagnosis of diabetic cognitive impairment (DCI) and investigation of effective medicines are significant to prevent or delay the occurrence of irreversible dementia.

OBJECTIVES

In this study, proteomics was applied to investigate the changes of hippocampal proteins after administration of Panax quinquefolius-Acorus gramineus (PQ-AG) to DCI rats, with a view to discover the differentially expressed proteins of PQ-AG action and elucidated the potential biological relationships.

METHODS

The model and PQ-AG group rats were injected intraperitoneally with streptozotocin, and the PQ-AG group rats were continuously administered with PQ-AG. Social interaction and Morris water maze were performed to evaluate the behavior of rats on the 17th week after the model was established, and DCI rats were screened out from the model group by a screening approach. The hippocampal protein differences were investigated with proteomics in DCI and PQ-AG-treated rats.

RESULTS

The learning and memory abilities and contact duration of DCI rats were improved after 16 weeks of PQ-AG administration. Altogether, 9 and 17 differentially expressed proteins were observed in control versus DCI rats and in DCI versus PQ-AG-treated rats, respectively. Three proteins were confirmed with western blotting analyses. These proteins were mainly involved in the pathways of JAK-STAT, apoptosis, PI3K/AKT, fork-head box protein O3, fructose, and mannose metabolism.

CONCLUSIONS

This suggested that PQ-AG ameliorated cognitive impairment of diabetic rats by influencing the above pathways and providing an experimental basis for the mechanism of DCI and PQ-AG.

Portulaca oleracea L. (purslane) improves the anti-inflammatory, antioxidant and autophagic actions of metformin in the hippocampus of diabetic demented rats

Great body of evidence links cognitive decline to diabetes/insulin resistance. In this study the effect of Portulaca oleracea (PUR) (100 mg/kg), Metformin (MET) (200 mg/kg), a first line diabetes mellitus type 2 therapy, and their combination on cognitive function and hippocampal markers in diabetic rats were assessed. Male rats were injected with streptozotocin (30 mg/kg on two successive weeks) followed by 4 weeks of treatment. Possible antioxidant, anti-inflammatory, and autophagy enhancing mechanisms of these drugs were investigated in the hippocampal tissue using spectrophotometry, ELISA, and western blotting. Diabetic rats suffered significant cognitive impairment in Morris's water maze, hippocampal TBARS elevation, GSH depletion, and SOD upregulation. In addition, diabetes promoted the secretion of hippocampal inflammatory cytokines, TNF-α and IL-1β, and depleted anti-inflammatory cytokines as IL-10. Such detrimental changes were reversed by MET and/or PUR. Notably, AMPK was upregulated by diabetes, then restored to normal by MET and/or PUR. The pattern of change in AMPK expression was concomitant with changes in oxidative and inflammatory burden. Hence, AMPK is believed to be a key mediator in most of the measured pre-AD markers in this study. However, from our results, PUR is believed to have non-AMPK dependent actions as well. In conclusion, antidiabetic agents as metformin and purslane extract proved to be invaluable in addressing the cognitive decline and hippocampal changes that arise as a complication of diabetes. They mainly acted through AMPK pathway; however, their usefulness was not limited to AMPK pathways since their combination was suggested to have a different mechanism.

14-3-3ζ Plays a key role in the modulation of neuroplasticity underlying the antidepressant-like effects of Zhi-Zi-Chi-Tang

BACKGROUND

Zhi-Zi-Chi-Tang (ZZCT) is an effective traditional Chinese medicinal formula. ZZCT has been used for the treatment of depression for centuries. Its clinical efficacy in relieving depression has been confirmed. However, the molecular mechanisms of ZZCT regarding neuroplasticity in the pathogenesis of depression have not yet been elucidated.

PURPOSE

The present study aimed to examine the effects of ZZCT on neuroplasticity in mice exposed to chronic unpredictable mild stress (CUMS), and to explore the underlying molecular mechanisms.

METHODS

For this purpose, a murine model of depression was established using the CUMS procedure. Following the intragastric administration of ZZCT or fluoxetine, classic behavioral experiments were performed to observe the efficacy of ZZCT as an antidepressant. Immunofluorescence was used to label and quantify microtubule-associated protein (MAP2) and postsynaptic density protein (PSD95) in the hippocampus. Golgi staining was applied to visualize the dendritic spine density of neurons in the hippocampi. Isolated hippocampal slices were prepared to induce long-term potentiation (LTP) in the CA1 area. The hippocampal protein expression levels of glycogen synthase kinase-3β (GSK-3β), p-GSK-3β (Ser9), cAMP response element binding protein (CREB), p-CREB (Ser133), brain-derived neurotrophic factor (BDNF) and 14-3-3ζ were detected using western blot analysis. The interaction of 14-3-3ζ and p-GSK-3β (Ser9) was examined using co-immunoprecipitation. LV-shRNA was used to knockdown 14-3-3ζ by an intracerebroventricular injection.

RESULTS

ZZCT (6 g/kg) and fluoxetine (20 mg/kg) alleviated depressive-like behavior, restored hippocampal MAP2⁺ PSD95⁺ intensity, and reversed the dendritic spine density of hippocampal neurons and LTP in the CA1 region of mice exposed to CUMS. Both low and high doses of ZZCT (3 and 6 g/kg) significantly promoted the binding of 14-3-3ζ to p-GSK-3β (Ser9) in the hippocampus, and ZZCT (6 g/kg) significantly promoted the phosphorylation of GSK-3β Ser9 and CREB Ser133 in the hippocampus. ZZCT (3 and 6 g/kg) upregulated hippocampal BDNF expression in mice exposed to CUMS. LV-sh14-3-3ξ reduced the antidepressant effects of ZZCT.

CONCLUSION

ZZCT exerted antidepressant effects against CUMS-stimulated depressive-like behavior mice. The knockdown of 14-3-3ζ using lentivirus confirmed that 14-3-3ζ was involved in the ZZCT-mediated antidepressant effects through GSK-3β/CREB/BDNF signaling. On the whole, these results suggest that the antidepressant effects of ZZCT are attributed to restoring damage by neuroplasticity enhancement via the 14-3-3ζ/GSK-3β/CREB/BDNF signaling pathway.

Early-life metabolic dysfunction impairs cognition and mitochondrial function in mice

The impact of overnutrition early in life is not restricted to the onset of cardiovascular and metabolic diseases, but also affects critical brain functions related to cognition. This study aimed to evaluate the relationship between peripheral metabolic and bioenergetic changes induced by a two-hit protocol and their impact on cognitive function in juvenile mice. Three-week-old male C57BL/6 mice received a high-fat diet (HFD) or control diet for 7 weeks, associated with 2 low doses of streptozotocin (STZ) or vehicle. Despite the absence of obesity, HFD+STZ impaired glucose metabolism and induced a trend towards cholesterol increase. The two-hit protocol impaired recognition and spatial memories in juvenile mice, without inducing a depressive-like behavior. HFD+STZ mice presented increased immunoreactivity for GFAP and a trend towards a decrease in NeuN in the hippocampus. The treatment caused a bioenergetic impairment in the hippocampus, characterized by a decrease in both O₂ consumption related to ATP production and in the maximum respiratory capacity. The thermogenic capacity of brown adipose tissue was impaired by the two-hit protocol, here verified through the absence of a decrease in O₂ consumption after uncoupled protein-1 inhibition and an increase in the reserve respiratory capacity. Impaired mitochondrial function was also observed in the liver of HFD+STZ juvenile mice, but not in their heart. These results indicate that exposure to HFD+STZ early in life has a detrimental impact on the bioenergetic and mitochondrial function of tissues with metabolic and thermogenic activities, which is likely related to hippocampal metabolic changes and cognitive impairment.

Geniposide protected against cerebral ischemic injury through the anti-inflammatory effect via the NF-κB signaling pathway

Context

Accumulated evidence indicates that geniposide exhibits neuroprotective effects in ischemic stroke. However, the potential targets of geniposide remain unclear.

Objective

We explore the potential targets of geniposide in ischemic stroke.

Materials and methods

Adult male C57BL/6 mice were subjected to the middle cerebral artery occlusion (MCAO) model. Mice were randomly divided into five groups: Sham, MCAO, and geniposide-treated (i.p. twice daily for 3 days before MCAO) at doses of 25, 75, or 150 mg/kg. We first examined the neuroprotective effects of geniposide. Then, we further explored via biological information analysis and verified the underlying mechanism in vivo and in vitro.

Results

In the current study, geniposide had no toxicity at concentrations of up to 150 mg/kg. Compared with the MCAO group, the 150 mg/kg group of geniposide significantly (P < 0.05) improved neurological deficits, brain edema (79.00 ± 0.57% vs 82.28 ± 0.53%), and infarct volume (45.10 ± 0.24% vs 54.73 ± 2.87%) at 24 h after MCAO. Biological information analysis showed that the protective effect was closely related to the inflammatory response. Geniposide suppressed interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) expression in the brain homogenate, as measured by enzyme-linked immunosorbent assay (ELISA). Geniposide upregulated A20 and downregulated TNF receptor-associated factor-6 and nuclear factor kappa-B phosphorylation in the MCAO model and lipopolysaccharide-treated BV2 cells at 100 μM.

Conclusions

Geniposide exhibited a neuroprotective effect via attenuating inflammatory response, as indicated by biological information analysis, in vivo and in vitro experiments, which may provide a potential direction for the application of geniposide in the treatment of ischemic stroke.

Genipin Attenuates Diabetic Cognitive Impairment by Reducing Lipid Accumulation and Promoting Mitochondrial Fusion via FABP4/Mfn1 Signaling in Microglia

The present study was conducted to evaluate the effect of genipin (GEN) on the microglia of diabetic cognitive impairment and explore its potential mechanism. Diabetic mice were induced by STZ/HFD, while GEN was intragastrically and intraventricularly treated. The human microglia cell HMC3 was induced by LPS/HG/PA. As a result, GEN attenuated diabetic symptoms and diabetic cognitive impairment-related behavior in novel object recognition, Morris water maze and passive avoidance tests. GEN inhibited M1 microglia polarization, lipid accumulation, oxidative stress and promoted mitochondrial fusion via FABP4/Mfn1. FABP4 overexpression, Mfn1 overexpression, selective FABP4 inhibitor BMS, and Mfn1 SiRNA were employed for investigating the mechanism. The inhibitory effect of GEN on ROS may be associated with NOX2 signaling and the translocation of p47phox/p67phox to the cell membrane. With the ROS scavenger NAC, it was proved that ROS participated in GEN-mediated inflammation and lipid accumulation. GEN inhibited the phosphorylation and nucleus translocation of NF-κB. GEN inhibited the ubiquitination of Mfn1, which was mediated by the E3 ligase Hrd1. GEN also enhanced microglia phagocytosis. Molecular docking predicted that GEN may interact with FABP4 by hydrogen bond at the S53 and R78 residues. In conclusion, GEN attenuated diabetic cognitive impairment by inhibiting inflammation, lipid accumulation and promoting mitochondrial fusion via FABP4/Mfn1 signaling.

Geniposide Alleviates Oxidative Damage in Hepatocytes through Regulating miR-27b-3p/Nrf2 Axis

Geniposide (GEN), a main compound extracted from Gardenia jasminoides fruit, has various biological activities including anti-inflammation, cellular damage alleviation, neuroprotection, and others. However, the effect of GEN on oxidative stress in hepatic cells is yet to be investigated. Our study uncovered that GEN eliminated excess intracellular free radicals by activating the Nrf2/ARE signaling pathway in H₂O₂-treated hepatocytes, while the protective effect was blocked by ML385 (an inhibitor of Nrf2). Moreover, H₂O₂ led to upregulation of miR-27b-3p in L02 cells, which was restrained by GEN. Overexpression of miR-27b-3p greatly weakened the antioxidant capacity of GEN in hepatocytes via directly targeting the Nrf2 gene. Our findings indicated that GEN treatment recovered H₂O₂-induced oxidative stress via targeting miR-27b-3p and thereby enhanced the antioxidant capacity by stimulating nuclear translocation and accumulation of Nrf2. These findings suggest that inhibition of miR-27b-3p to activate the Nrf2/ARE pathway by GEN is a potential alternative for hepatic oxidative damage alleviation.

CaMKIV/CREB/BDNF signaling pathway expression in prefrontal cortex, amygdala, hippocampus and hypothalamus in streptozotocin-induced diabetic mice with anxious-like behavior

Individuals with diabetes mellitus (DM) tend to manifest anxiety and depression, which could be related to changes in the expression of calcium/calmodulin-dependent protein kinase IV (CaMKIV), transcription factor cyclic AMP-responsive element binding protein (CREB), phosphorylated CREB (pCREB) and brain-derived neurotrophic factor (BDNF) in different brain regions. The objective of this study was to determine whether mice with type 1 diabetes (T1DM) induced with streptozotocin show a profile of anxious-type behaviors and alterations in the expression/activity of CaMKIV, CREB, pCREB and BDNF in different regions of the brain (prefrontal cortex, amygdala, hippocampus and hypothalamus) in comparison to non-diabetic mice (NDB). Mice with 3 months of chronic DM showed an anxious-like behavioral profile in two anxiety tests (Open Field and Elevated Plus Maze), when compared to NDB. There were significant differences in the expression of cell signaling proteins: diabetic mice had a lower expression of CaMKIV in the hippocampus, a greater expression of CREB in the amygdala and hypothalamus, as well as a lower pCREB/CREB in hypothalamus than NDB mice (P < 0.05). This is the first study evaluating the expression of CaMKIV in the brain of animals with DM, who presented lower expression of this protein in the hippocampus. In addition, it is the first time that CREB was evaluated in amygdala and hypothalamus of animals with DM, who presented a higher expression. Further research is necessary to determine the possible link between expression of CaMKIV and CREB, and the behavioral profile of anxiety in diabetic animals.

Rapid identification of chemical components in Zhizi Baipi decoction by ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry coupled with a novel informatics UNIFI platform

Zhizi Baipi Decoction is a classic traditional Chinese medicine formula for the treatment of jaundice and various liver diseases. The chemical components of Zhizi baipi decoction were not clear resulting from the paucity of relevant studies, which hindered the elucidation of the pharmacological mechanism, the comprehensive development and utilization of Zhizi baipi decoction in clinical. In this study, ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry combined with UNIFI natural product information analysis platform was used to rapidly analyze and identify the chemical components in Zhizi baipi decoction. A total of 122 chemical components, including 53 flavonoids, 16 alkaloids, 25 terpenoids, 5 phenylpropanoids, 14 organic acids, and 7 others, were identified from Zhizi baipi decoction. These compounds may be the active components of Zhizi baipi decoction. The method established in this study can systematically, rapidly, and accurately resolve the chemical components in Zhizi baipi decoction, which lays the foundation for further establishment of the pharmacodynamic substance basis and quality control of Zhizi baipi decoction. This article is protected by copyright. All rights reserved.

Association of gut microbiota with sort-chain fatty acids and inflammatory cytokines in diabetic patients with cognitive impairment: A cross-sectional, non-controlled study

Emerging evidence suggests that gut microbiota, short-chain fatty acids (SCFAs), and inflammatory cytokines play important roles in the pathogenesis of diabetic cognitive impairment (DCI). However, little is known about alterations of gut microbiota and SCFA levels as well as the relationships between inflammatory cytokines and cognitive function in Chinese DCI patients. Herein, the differences in the gut microbiota, plasma SCFAs, and inflammatory cytokines in DCI patients and type 2 diabetes mellitus (T2DM) patients were explored. A cross-sectional study of 30 DCI patients and 30 T2DM patients without mild cognitive impairment (MCI) was conducted in Tianjin city, China. The gut microbiota, plasma SCFAs, and inflammatory cytokines were determined using 16S ribosomal RNA (rRNA) gene sequencing, gas chromatography-mass spectrometry (GC-MS), and Luminex immunofluorescence assays, respectively. In addition, the correlation between gut microbiota and DCI clinical characteristics, SCFAs, and inflammatory cytokines was investigated. According to the results, at the genus level, DCI patients presented a greater abundance of Gemmiger, Bacteroides, Roseburia, Prevotella, and Bifidobacterium and a poorer abundance of Escherichia and Akkermansia than T2DM patients. The plasma concentrations of acetic acid, propionic acid, isobutyric acid, and butyric acid plummeted in DCI patients compared to those in T2DM patients. TNF-α and IL-8 concentrations in plasma were significantly higher in DCI patients than in T2DM patients. Moreover, the concentrations of acetic acid, propionic acid, butyric acid, and isovaleric acid in plasma were negatively correlated with TNF-α, while those of acetic acid and butyric acid were negatively correlated with IL-8. Furthermore, the abundance of the genus Alloprevotella was negatively correlated with butyric acid, while that of Holdemanella was negatively correlated with propanoic acid and isobutyric acid. Fusobacterium abundance was negatively correlated with propanoic acid. Clostridium XlVb abundance was negatively correlated with TNF-α, while Shuttleworthia abundance was positively correlated with TNF-α. It was demonstrated that the gut microbiota alterations were accompanied by a change in SCFAs and inflammatory cytokines in DCI in Chinese patients, potentially causing DCI development. These findings might help to identify more effective microbiota-based therapies for DCI in the future.

Microglia in depression: an overview of microglia in the pathogenesis and treatment of depression

Major depressive disorder is a highly debilitating psychiatric disorder involving the dysfunction of different cell types in the brain. Microglia are the predominant resident immune cells in the brain and exhibit a critical role in depression. Recent studies have suggested that depression can be regarded as a microglial disease. Microglia regulate inflammation, synaptic plasticity, and the formation of neural networks, all of which affect depression. In this review, we highlighted the role of microglia in the pathology of depression. First, we described microglial activation in animal models and clinically depressed patients. Second, we emphasized the possible mechanisms by which microglia recognize depression-associated stress and regulate conditions. Third, we described how antidepressants (clinical medicines and natural products) affect microglial activation. Thus, this review aimed to objectively analyze the role of microglia in depression and focus on potential antidepressants. These data suggested that regulation of microglial actions might be a novel therapeutic strategy to counteract the adverse effects of devastating mental disorders.

Updated Pharmacological Effects, Molecular Mechanisms, and Therapeutic Potential of Natural Product Geniposide

At present, the potential of natural products in new drug development has attracted more and more scientists’ attention, and natural products have become an important source for the treatment of various diseases or important lead compounds. Geniposide, as a novel iridoid glycoside compound, is an active natural product isolated from the herb Gardenia jasminoides Ellis (GJ) for the first time; it is also the main active component of GJ. Recent studies have found that geniposide has multiple pharmacological effects and biological activities, including hepatoprotective activity, an anti-osteoporosis effect, an antitumor effect, an anti-diabetic effect, ananti-myocardial dysfunction effect, a neuroprotective effect, and other protective effects. In this study, the latest research progress of the natural product geniposide is systematically described, and the pharmacological effects, pharmacokinetics, and toxicity of geniposide are also summarized and discussed comprehensively. We also emphasize the major pathways modulated by geniposide, offering new insights into the pharmacological effects of geniposide as a promising drug candidate for multiple disorders.

Ginkgolide B inactivates the NLRP3 inflammasome by promoting autophagic degradation to improve learning and memory impairment in Alzheimer's disease

The NLR family, pyrin domain containing 3 (NLRP3) inflammasome drives the progression of Alzheimer's disease (AD). Ginkgolide B (GB) is a potential anti-inflammatory compound that controls neuro-inflammation. The aim of this study was to evaluate the effect of GB on the NLRP3 inflammasome in AD. The effect of GB on the conversion between the M1 and M2 microglial phenotype was examined using quantitative real-time PCR and immunostaining. Western blotting assays and ELISA were used to detect changes in neuro-inflammation following GB treatment, including the NLRP3 inflammasome pathway and autophagy. In order to evaluate the cognitive function of male senescence-accelerated mouse prone 8 (SAMP8) mice, behavioral tests, including the Morris water maze and novel object recognition tests, were performed. GB significantly decreased the intracellular pro-inflammatory cytokine levels in lipopolysaccharide-treated BV2 cells and improved cognitive behavior in SAMP8 mice. Moreover, GB deactivated the NLRP3 inflammasome, and this effect was dependent on autophagy. Ubiquitination was associated with GB-induced autophagic NLRP3 degradation. These results were further validated in the hippocampus of SAMP8 mice. Thus, GB exerted a neuroprotective effect on the cognitive function of SAMP8 mice by suppressing the activation of NLRP3 inflammasome via autophagic degradation.

Securidaca inappendiculata Polyphenol Rich Extract Counteracts Cognitive Deficits, Neuropathy, Neuroinflammation and Oxidative Stress in Diabetic Encephalopathic Rats via p38 MAPK/Nrf2/HO-1 Pathways

Diabetic encephalopathy is one of the serious emerging complication of diabetes. Securidaca inappendiculata is an important medicinal plant with excellent antioxidant and anti-inflammatory properties. This study investigated the neuroprotective effects of S. inappendiculata polyphenol rich extract (SiPE) against diabetic encephalopathy in rats and elucidated the potential mechanisms of action. Type 2 diabetes mellitus (T2DM) was induced using high fructose solution/intraperitoneal injection of streptozotocin and the diabetic rats were treated with SiPE (50, 100 and 200 mg/kg) for 8 weeks. Learning and memory functions were assessed using the Morris water and Y maze tests, depressive behaviour was evaluated using forced swimming and open field tests, while neuropathic pain assessment was assessed using hot plate, tail immersion and formalin tests. After the experiments, acetylcholinesterase (AChE), oxidative stress biomarkers and proinflammatory cytokines, caspase-3 and nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) were determined by ELISA kits. In addition, the expression levels of p38, phospho-p38 (p-p38), nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were determined by western blot analyses. The results indicated that SiPE administration significantly lowered blood glucose level, attenuated body weight loss, thermal/chemical hyperalgesia, improved behavioural deficit in the Morris water maze, Y maze test and reduced depressive-like behaviours. Furthermore, SiPE reduced AChE, caspase-3, NF-κB, malonaldehyde malondialdehyde levels and simultaneously increased antioxidant enzymes activity in the brain tissues of diabetic rats. SiPE administration also significantly suppressed p38 MAPK pathway and upregulated the Nrf2 pathway. The findings suggested that SiPE exerted antidiabetic encephalopathy effects via modulation of oxidative stress and inflammation.

Properties and molecular mechanisms underlying geniposide-mediated therapeutic effects in chronic inflammatory diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Geniposide (GE) is ubiquitous in nearly 40 species of plants, among which Gardenia jasminoides J. Ellis has the highest content, and has been used ethnopharmacologically to treat chronic inflammatory diseases. As a traditional Chinese medicine, Gardenia jasminoides J. Ellis has a long history of usage in detumescence and sedation, liver protection and cholestasis, hypotension and hemostasis. It is commonly used in the treatment of diabetes, hypertension, jaundice hepatitis, sprain and contusion. As a type of iridoid glycosides extracted from Gardenia jasminoides J. Ellis, GE has many pharmacological effects, such as anti-inflammatory, anti-angiogenesic, anti-oxidative, etc. AIM OF THE REVIEW: In this article, we reviewed the sources, traditional usage, pharmacokinetics, toxicity and therapeutic effect of GE on chronic inflammatory diseases, and discussed its potential regulatory mechanisms and clinical application.

RESULTS

GE is a common iridoid glycoside in medicinal plants, which has strong activity in the treatment of chronic inflammatory diseases. A large number of in vivo and in vitro experiments confirmed that GE has certain therapeutic value for a variety of chronic inflammation disease. Its mechanism of function is mainly based on its anti-inflammatory, anti-oxidant, neuroprotective properties, as well as regulation of apoptotsis. GE plays a role in the treatment of chronic inflammatory diseases by regulating cell proliferation and apoptosis, realizing the dynamic balance of pro/anti-inflammatory factors, improving the state of oxidative stress, and restoring abnormally expressed inflammation-related pathways.

CONCLUSION

According to its extensive pharmacological effects, GE is a promising drug for the treatment of chronic inflammatory diseases.

Effect of Theaflavin on Inflammatory and Remolding of Airway in the Asthma Mice

To study the effect of theaflavin on the airway’s inflammation and remodeling in mice with asthma. The mice were divided into the control, asthma model, and the theaflavin treatment groups to analyze the changes in pulmonary compliance and lung resistance of the mice with asthma to theaflavin treatment. The theaflavin treatment groups consisted of the low-dose (15 mg/kg theaflavin-intragastric administration), medium-dose (30 mg/kg), and high-dose (60 mg/kg) groups. Alveoli lavage liquid was gathered from the mice to count the number of inflammatory cells, and the levels of interleukin 4 (IL-4), interleukin 5 (IL-5), interleukin 13 (IL-13), and eotaxin were detected by ELISA. The levels of proteins, such as transforming growth factor-1 (TGF-1), alpha-smooth muscle actin (α-SMA), CyclinD1,CyclinD2, Toll-like receptors-4 (TLR4), myeloid differentiation factor 88 (MyD88), and NF-κBp65, which showed the performance of lung tissue was tested by Western blotting. Compared to the control group, the lung resistance of the asthma model mice was increased, and compliance was decreased after increasing concentrations of acetylcholine (Mch) stimulation. Compared to the asthma model group, the pulmonary resistance was decreased, and pulmonar compliance was increased according to the rising concentration of Mch in theaflavin-L, theaflavin-M and theaflavin-H mice. Compared to the control group, the number of cells, macrophages, acidophilic cells, lymph, and neutrophile granulocytes increased in the alveolar perfusion fluid of asthmatic mice. The level of interleukin 4, interleukin 5, interleukin 13, and eotaxin, TGF-β1, α-SMA, Cyclin D1, MyD88, TLR4, Cyclin D2, and NF-κBp65 proteins of the lung was also increased. Compared to the model group, the number of cells, macrophages, acidophilic cells, lymph, and neutrophile granulocytes were decreased successively in the alveolar lavage fluid in the theaflavin-L, theaflavin-M, and theaflavin-H mice. Meanwhile, the content of interleukin 4, interleukin 5, interleukin 13, and eotaxin were decreased successively, and the level of TGF-β1, α-SMA, Cyclin D1, MyD88, TLR4, Cyclin D2, and NF-κBp65 protein increased successively in the theaflavin-L, theaflavin-M, and theaflavin-H mice. Theaflavin has been found to reduce airway inflammation, impede airway remodeling, and decrease the TLR 4/MyD88/NF-κB signaling in asthmatic mice.

CREB nuclear transcription activity as a targeting factor in the treatment of diabetes and diabetes complications

Diabetes mellitus is a metabolic disorder diagnosed by elevated blood glucose levels and a defect in insulin production. Blood glucose, an energy source in the body, is regenerated by two fundamental processes: glycolysis and gluconeogenesis. These two processes are the main mechanisms used by humans and many other animals to maintain blood glucose levels, thereby avoiding hypoglycaemia. The released insulin from pancreatic β-cells activates glycolysis. However, the glucagon released from the pancreatic α-cells activates gluconeogenesis in the liver, leading to pyruvate conversion to glucose-6-phosphate by different enzymes such as fructose 1,6-bisphosphatase and glucose 6-phosphatase. These enzymes' expression is controlled by the glucagon/ cyclic adenosine 3',5'-monophosphate (cAMP)/ proteinkinase A (PKA) pathway. This pathway phosphorylates cAMP-response element-binding protein (CREB) in the nucleus to bind it to these enzyme promoters and activate their expression. During fasting, this process is activated to supply the body with glucose; however, it is overactivated in diabetes. Thus, the inhibition of this process by blocking the expression of the enzymes via CREB is an alternative strategy for the treatment of diabetes. This review was designed to investigate the association between CREB activity and the treatment of diabetes and diabetes complications. The phosphorylation of CREB is a crucial step in regulating the gene expression of the enzymes of gluconeogenesis. Many studies have proven that CREB is over-activated by glucagon and many other factors contributing to the elevation of fasting glucose levels in people with diabetes. The physiological function of CREB should be regarded in developing a therapeutic strategy for the treatment of diabetes mellitus and its complications. However, the accessible laboratory findings for CREB activity of the previous research still not strong enough for continuing to the clinical trial yet.

Geniposide protects depression through BTK/JAK2/STAT1 signaling pathway in lipopolysaccharide-induced depressive mice

The purpose of this study was to investigate the antidepressant mechanism of GEN (geniposide) on depression mice induced by LPS. The mice were intragastrically treated with GEN (10 mg/kg/d or 40 mg/kg/d) or ibrutinib for continuous 7 days prior to LPS injection. The anxiety- and depression-like behaviors of mice were assessed via behavioral tests (sucrose preference test (SPT), tail suspension test (TST), forced swimming test (FST), and open-field test (OFT)). Microglial BV2 cells were treated with GEN or/and ibrutinib and stimulated with LPS. The productions of pro-inflammatory cytokines IL-6 and TNF-α in hippocampus, serum, and supernatant were detected by ELISA. The correlative proteins BTK, p-BTK, JAK2, p-JAK2, STAT1, p-STAT1, BDNF, TrkB, and p-TrkB were assessed through western blot. As a result, GEN ameliorated the anxiety- and depression-like behaviors of mice in behavioral tests. GEN treatment also regulated microglia polarization towards anti-inflammatory phenotype M2 and inhibited the production of pro-inflammatory cytokines IL-6 and TNF-α. In addition, with the application of ibrutinib, the selective inhibitor of BTK, it was proclaimed that the administration of GEN restrained the activation of JAK2/STAT1 pathway via attenuating the hyperphosphorylation of BTK both in mice and BV2 cells. Furthermore, it was also found that GEN activated BDNF/TrkB neuroprotective signaling pathway through the reduction of BTK phosphorylation. From the overall results, we suggested that GEN exerted a beneficial effect on LPS-induced depression in mice possibly through the modulation of BTK/JAK2/STAT1 signaling.

Zinc Supplementation Decreases Obesity-Related Neuroinflammation and Improves Metabolic Function and Memory in Rats

OBJECTIVE

The purpose of this study was to evaluate the effects of zinc (Zn) supplementation on metabolic and neuroinflammatory parameters in cafeteria diet (CAF)-induced obesity in Wistar rats.

METHODS

Animals were divided into four groups: control diet (CT); CT+Zn; CAF; CAF+Zn. The diet was administered for 20 weeks; Zn treatment (10 mg/kg/d) started at week 16 and it was conducted until the end of the diet protocol. Weight gain, visceral fat, and plasma levels of glucose, triglycerides, insulin, TNF-α, and IL-6, as well as homeostatic model assessment of insulin resistance, were assessed. Glial fibrillary acidic protein (GFAP) and ionized calcium binding adaptor molecule 1 (Iba-1) expression in the cerebral cortex and toll-like receptor 4 (TLR-4) in the cerebral cortex and hippocampus were evaluated. Memory was assessed by the novel object recognition test.

RESULTS

CAF diet increased weight gain, visceral fat, and plasma glucose, triglyceride, and TNF-α levels. Zn reversed the hyperglycemia caused by CAF diet and reduced IL-6 levels. In the cerebral cortex, GFAP was similar between groups; Iba-1 was increased by CAF diet but reduced in the CAF+Zn group. Zn reduced CAF-dependent TLR-4 increase in the hippocampus but not in the cerebral cortex. CAF-fed animals showed impaired recognition memory, whereas Zn reversed it.

CONCLUSIONS

These findings demonstrate that Zn partially reverted obesity-related metabolic dysfunction and reduced neuroinflammation and memory deficit caused by CAF diet.

The role of CCR5 in the protective effect of Esculin on lipopolysaccharide-induced depressive symptom in mice

BACKGROUND

The purpose of this study was to evaluate whether Esculin could improve the depressive symptom induced by LPS in mice and explore the role of CCR5 in its potential mechanism.

METHODS

Mice were stimulated with LPS to establish depression model and treated with Esculin. The emotional alteration was assessed via behavior tests. The ELISA assay and western blot analysis were applied to detect the expressions of inflammatory cytokines and correlative proteins.

RESULTS

As a result, Esculin played a protective role in LPS-induced depressive dysfunction, which was possible through the reduction of M1 microglia, and elevation of M2 microglia by inhibiting TLR4/NF-κB signaling pathway regulated by CCR5. Besides, Esculin led to up-regulation of the CREB/BDNF neuroprotective pathway, and suppression of inflammatory cytokines both in the central and peripheral system. BV2 cells were stimulated with LPS to further elucidate the accordant mechanism in vitro. Molecular docking results suggested that Esc bound to CCR5 at amino acid residues TYR187 and THR105 through hydrogen-bonding.

LIMITATIONS

Transgenic animals might be useful for the further investigation.

CONCLUSIONS

From the overall results, we concluded that Esculin might exert a beneficial effect on LPS-induced depression in mice and represent an effective treatment for depression.

Geniposide inhibits proliferation and induces apoptosis of diffuse large B-cell lymphoma cells by inactivating the HCP5/miR-27b-3p/MET axis

Diffuse large B-cell lymphoma (DLBCL) is commonly treated with R-CHOP, but ~30 to 50% of the patients are poorly responsive to this strategy. Geniposide, an extract from the Gardenia jasminoides Ellis, plays antitumor roles in human gastric cancer, hepatocellular carcinoma, and oral squamous carcinoma. However, the effects of geniposide treatment on DLBCL cells, as well as its underlying mechanism, are still unknown. Here, we found that geniposide inhibited the proliferation of OCI-LY7 and OCI-LY3 cells in a dose-dependent manner. Furthermore, geniposide increased the percentage of apoptotic cells and upregulated the levels of cleaved PARP and cleaved caspase-3 in DLBCL cells. Interestingly, geniposide treatment significantly reduced the expression of the long noncoding RNA HLA complex P5 (lncRNA HCP5) in DLBCL cells. HCP5 expression was revealed to be upregulated in DLBCL tissues and cell lines. Moreover, HCP5 knockdown resulted in proliferation inhibition and apoptosis in OCI-LY7 and OCI-LY3 cells. miR-27b-3p was predicted as a potential target of HCP5 using the lnCAR web tool. Both HCP5 silencing and geniposide treatment increased the level of miR-27b-3p in DLBCL cells. Accordingly, a luciferase reporter assay identified miR-27b-3p as a direct target of HCP5. The expression of miR-27b-3p was upregulated and inversely correlated with the HCP5 level in DLBCL tissues. HCP5 knockdown reduced MET protein expression, which was subsequently rescued by miR-27b-3p silencing in DLBCL cells. Importantly, the restoration of MET partially reversed the geniposide-induced proliferation inhibition and apoptosis of DLBCL cells. In conclusion, geniposide inhibits the proliferation and induces the apoptosis of DLBCL cells at least partially by regulating the HCP5/miR-27b-3p/MET axis, indicating a potential strategy for DLBCL treatment.