Leukemia-derived Exosomes Can Induce Responses Related to Tumorigenesis on Non-tumoral Astrocytes

Cancer is the second cause of disability and death worldwide. Identifying communication between cancer cells and normal cells can shed light on the underlying metastatic mechanisms. Among different suspected mechanisms, exosomes derived from cancer cells have been introduced as a main key player in metastatic processes. To this point, we evaluated the effects of exosomes derived from the leukemia nalm6 cell line on astrocytes behavior, such as proliferation and inflammatory pathways. To assess astrocyte responses, data were obtained by MTT, Annexin/PI to indicate proliferation and apoptosis. Further analyses were performed by Real-time PCR and western blot to assess the expression of IL6, IL1β, NFkβ, TNFα, and aquaporin-4 (AQP4). Our results demonstrated that the proliferation of astrocytes was significantly increased when treated with exosomes derived from Nalm6 cells. We also found that the expression of IL6, IL1β, NFkβ, and TNFα were significantly increased at the mRNA level when exposed to exosomes derived from Nalm6 cells. Finally, the mRNA and protein levels of AQP4 were profoundly increased after being treated by exosomes derived from Nalm6 cells. To sum up, our data indicated that the secretion of cancer cells could induce responses related to tumorigenesis. However, further studies on this topic are warranted to clarify exosomes' role in metastasis.

Synbiotics of Bifidobacterium breve MCC1274 and lactulose enhances production of tryptophan metabolites in fermented human fecal communities

Probiotics and prebiotics have beneficial effects on host physiology via metabolites from the gut microbiota in addition to their own. Here, we used a pH-controlled single-batch fermenter as a human gut microbiota model. We conducted fecal fermentation with Bifidobacterium breve MCC1274 (probiotic), lactulose (prebiotic), or a combination of both (synbiotic) to evaluate their influence on the gut environment. Fecal inoculum without the probiotic and prebiotic was used as the control. Principal coordinate analysis (PCoA), based on the composition of gut microbiota, showed a significant difference among the groups. The relative abundance of Bifidobacterium was significantly higher in the synbiotic group, compared to that in the other three treatment groups. The relative abundance of Blautia was the highest in the control group among the four groups. CE-TOFMS and LC-TOFMS showed that the number of metabolites detected in the synbiotic group was the highest (352 in total); 29 of the 310 hydrophilic metabolites and 17 of the 107 lipophilic metabolites were significantly different among the four groups in the Kruskal-Wallis test. A clustering based on 46 metabolites indicated that tryptophan-metabolites such as indole-3-lactic acid (ILA), indole-3-ethanol, and indole-3-carboxaldehyde, were included in a sub cluster composed of metabolites enriched in the synbiotic group. Spermidine, a major polyamine, was enriched in the two groups supplemented with the probiotic whereas spermine was enriched only in the synbiotic group. Not all metabolites enriched in the probiotic and/or synbiotic groups were found in the monocultures of the probiotic strain with or without the prebiotics. This implies that some of the metabolites were produced through the interaction of the fecal microbiota with the inoculated probiotic strain. Co-abundance networking analysis indicated the differences in the correlations between the relative abundance of the fecal microbiota genus and the tryptophan metabolites in each group. There was a strong correlation between ldh4 gene abundance and ILA concentration in the fecal fermentation. The copy number of ldh4 gene was significantly higher in the groups with the probiotic than that in the control group. In conclusion, synbiotics could enhance the production of signaling molecules in the gut environment. Our results provide an insight into more effective administration of probiotics at the molecular level.

Synthesis, Antioxidant, and Antihypoxia Activities of 6,7,8,4′-Tetrahydroxyisoflavone and 6,7,8,3′,4′-Pentahydroxyisoflavone

In the present study, 6,8-dihydroxydaidzein (6,8-DHD or 6,7,8,4′-tetrahydroxyisoflavone) and 6,8,3′-trihydroxydaidzein (6,8,3′-THD or 6,7,8,3′,4′-pentahydroxyisoflavone) were synthesized via a facile and efficient way using commercially available formononetin as starting material. Their structures were confirmed using spectroscopic analyses (infrared, nuclear magnetic resonance, and mass spectrometry). The purity was checked by ultra-high performance liquid chromatography. Their antioxidant activities were evaluated via 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay and reducing power assay using ascorbic acid (vitamin C) as a reference compound. The antihypoxia capacity was determined by a hypoxia injury model in PC12 cells. Our study revealed that 6,8-DHD and 6,8,3′-THD exhibited higher antioxidant activities than that of vitamin C and could protect PC12 cells against hypoxia-induced damage. These results indicate that 6,8-DHD and 6,8,3′-THD are excellent antioxidant agents and could be used for alleviating injury induced by hypoxia.

The Dissemination, Influence, and Efficiency of Jameson’s Cultural Theory Combined with Chinese Mass Culture and Mass Sports Culture in the Sustainable Development of China

Fredric Jameson's cultural theory forms a crucial part of the Western Marxist theory. Jameson's postmodern cultural theory includes cultural expansion, cultural history, cultural hyperspace, cultural ideology, and so on. The cultural expansion includes the outline of popular sports culture. (1) Content: In order to further understand the acceptance of Jameson's cultural theory in China, this paper explores the communication of Jameson's cultural theory in different cultural groups, different regions, and different communication channels in China based on the questionnaire survey in a larger span of social groups. Meanwhile, based on Jameson's theory, it also reveals that sports is an effective way to achieve national stability and rejuvenation. Mainstream culture not only leads fashion, educates the people, serves society, and promotes development but also has the common characteristics of mass culture, commerce, entertainment, popularity, and media dependence. Sports is both mainstream culture and mass culture, which is the positive energy shared by both. (2) Methods: In order to understand the special meaning of Jameson's cultural theory and its influence on Chinese mass culture and sports, this paper systematically explains Jameson's cultural theory and gives a critical explanation to Jameson's cultural theory, different regions, and different communication channels in China based on the questionnaire survey in a large span of mass culture and sports groups. (3) Results: the majority of readers who buy and read Jameson's cultural works are mainly 25–35 years old with high educational background. The top three regions for the number of consumers who buy his papers and books are Zhejiang, Hubei, and Guangzhou; the top three regions in the number of understanding Jameson's cultural theory are Beijing, Shanghai, and Shenzhen; 41.62% of the respondents only know Jameson's name but have not been exposed to his work; and 34.59% of the respondents have learned about his work through news feeds. (4) Conclusion: the influence of Jameson's cultural theory on Chinese mass culture and sports community is on the rise. Systematic sorting and interpretation of Jameson's cultural knowledge can provide support for Chinese mass culture and mass sports culture to carry forward socialist cultural thoughts.

The NLRP3 Inflammasome Pathway: A Review of Mechanisms and Inhibitors for the Treatment of Inflammatory Diseases

The NLRP3 inflammasome is a multiprotein complex that plays a pivotal role in regulating the innate immune system and inflammatory signaling. Upon activation by PAMPs and DAMPs, NLRP3 oligomerizes and activates caspase-1 which initiates the processing and release of pro-inflammatory cytokines IL-1β and IL-18. NLRP3 is the most extensively studied inflammasome to date due to its array of activators and aberrant activation in several inflammatory diseases. Studies using small molecules and biologics targeting the NLRP3 inflammasome pathway have shown positive outcomes in treating various disease pathologies by blocking chronic inflammation. In this review, we discuss the recent advances in understanding the NLRP3 mechanism, its role in disease pathology, and provide a broad review of therapeutics discovered to target the NLRP3 pathway and their challenges.

Erteng Tongbi Decoction ameliorates collagen-induced arthritis in mice via modulating T cell differentiation and cytokines balance

ETHNOPHARMACOLOGICAL RELEVANCE

Herbs have been commonly used for the treatment of rheumatoid arthritis (RA). It has been verified that Erteng Tongbi Decoction has good therapeutic effects on RA, while, relatively few studies on the relationship between its components and anti-rheumatoid efficacy were carried out.

AIM OF THE STUDY

To discuss the anti-RA effects of Erteng Tongbi Decoction on collagen-induced arthritis (CIA) in mice and the influence of T cell differentiation and cytokines balance.

MATERIALS AND METHODS

Separate researches on the two traditional Chinese medicines of the Erteng Tongbi Decoction were conducted. First, a murine peritoneal macrophage model was established, and then the cytokines levels and macrophage maturity were measured to select the best extraction solvent. Furthermore, ethanol extracts were partitioned successively with four kinds of solvents, and the anti-inflammatory parts were selected by the same vitro model. Subsequently, mice were arbitrarily divided into control, CIA model, positive control, effective parts alone or in combination. After 20 days of oral administration, the weight, hind paw volume, rheumatism index value, and the pathological changes were checked to assess the obvious level of arthritis. Furthermore, the levels of IL-6, TNF-α, IL-10, and IL-17A in serum and the balance of Th17/Treg and Th1/Th2 cells in spleen and mesenteric lymph nodes (MLN) was detected. Finally, the major active constituents were identified.

RESULTS

In vitro, the anti-inflammatory effects of ethanol extracts was much better than water extract. In addition, the effective parts of Celastrus orbiculatus Thunb. ethanol extract were petroleum ether parts and dichloromethane parts. The effective parts of Spatholobus suberectus Dunn. ethanol extracts was petroleum ether parts and ethyl acetate parts screened. In vivo, effective parts compatibility could inhibit the progression of inflammation by modulating T cell differentiation and cytokines balance. Constituent analysis revealed that effective parts contained sesquiterpenes alkaloids, phenolic acids, and flavanols.

CONCLUSIONS

Erteng Tongbi Decoction could notably ameliorate CIA mice by modulating T cell differentiation and cytokines balance and support its application in folk medicine.

The potential anti-amyloidogenic candidate, SPA1413, for Alzheimer's disease

BACKGROUND AND PURPOSE

Recently, isoflavone derivatives have been shown to have neuroprotective effects against neurological disorders. For instance, genistein attenuated the neuroinflammation and amyloid-β accumulation in Alzheimer's disease animal models, suggesting the potential for use to prevent and treat Alzheimer's disease.

EXPERIMENTAL APPROACH

Here, 50 compounds, including isoflavone derivatives, were constructed and screened for the inhibitory effects on amyloid-β₄₂ fibrilization and oligomerization using the high-throughput screening formats of thioflavin T assay and multimer detection system, respectively. The potential neuroprotective effect of t3-(4-hydroxyphenyl)-2H-chromen-7-ol (SPA1413), also known as dehydroequol, idronoxil or phenoxodiol, was evaluated in cells and in 5xFAD (B6SJL) transgenic mouse, a model of Alzheimer's disease.

KEY RESULTS

SPA1413 had a potent inhibitory action on both amyloid-β fibrilization and oligomerization. In the cellular assay, SPA1413 prevented amyloid-β-induced cytotoxicity and reduced neuroinflammation. Remarkably, the oral administration of SPA1413 ameliorated cognitive impairment, decreased amyloid-β plaques and activated microglia in the brain of 5xFAD (B6SJL) transgenic mouse.

CONCLUSION AND IMPLICATIONS

Our results strongly support the repurposing of SPA1413, which has already received fast-track status from the US Food and Drug Administration (FDA) for cancer treatment, for the treatment of Alzheimer's disease due to its potent anti-amyloidogenic and anti-neuroinflammatory actions.

Investigation of inhibition effect of daidzein on osteosarcoma cells based on experimental validation and systematic pharmacology analysis

Objective

This study aims to explore the effect of daidzein, which is a natural isoflavone compound mainly extracted from soybeans, on osteosarcoma and the potential molecular mechanism.

Material and Methods

143B and U2OS osteosarcoma cells were treated with gradient concentrations of daidzein, and MTT assay was used to determine the cell proliferation capacity and IC₅₀. Hoechst 33342 staining and Annexin V-FITC/PI detection were used to determine apoptosis. Cell cycle was analyzed by flow cytometry, and migration ability were detected by transwell assays and scratch wound assay. An osteosarcoma xenograft mice model was applied to investigate the effect of daidzein on osteosarcoma in vivo. Systematic pharmacology and molecular modeling analysis were applied to predict the target of daidzein to osteosarcoma, and the target Src was verified by western blotting. We also observed the effect of daidzein on cell proliferation and apoptosis of Src-overexpressing osteosarcoma cells.

Results

In vitro, daidzein significantly inhibited 143B and U2OS osteosarcoma cell proliferation and migration, and induced cell cycle arrest. In vivo, daidzein exerts antitumor effects in osteosarcoma xenograft mice. After systematic screening and analysis, Src-MAPK signaling pathway was predicted as the highest-ranked pathway. Western blot demonstrated that daidzein inhibited phosphorylation of the Src-ERK pathway in osteosarcoma cells. Also, overexpression of Src could partially reverse the inhibitory effects of daidzein on osteosarcoma cell proliferation.

Conclusion

Daidzein exerts an antitumor effect on osteosarcoma, and the mechanism may be through the Src-ERK pathway.

Syk/NF-κB-targeted anti-inflammatory activity of Melicope accedens (Blume) T.G. Hartley methanol extract

ETHNOPHARMACOLOGICAL RELEVANCE

Melicope accedens (Blume) Thomas G. Hartley is a plant included in the family Rutaceae and genus Melicope. It is a native plant from Vietnam that has been used for ethnopharmacology. In Indonesia and Malaysia, the leaves of M. accedens are applied externally to decrease fever.

AIM OF THE STUDY

The molecular mechanisms of the anti-inflammatory properties of M. accedens are not yet understood. Therefore, we examined those mechanisms using a methanol extract of M. accedens (Ma-ME) and determined the target molecule in macrophages.

MATERIALS AND METHODS

We evaluated the anti-inflammatory effects of Ma-ME in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and in an HCl/EtOH-triggered gastritis model in mice. To investigate the anti-inflammatory activity, we performed a nitric oxide (NO) production assay and ELISA assay for prostaglandin E2 (PGE₂). RT-PCR, luciferase gene reporter assays, western blotting analyses, and a cellular thermal shift assay (CETSA) were conducted to identify the mechanism and target molecule of Ma-ME. The phytochemical composition of Ma-ME was analyzed by HPLC and LC-MS/MS.

RESULTS

Ma-ME suppressed the production of NO and PGE₂ and the mRNA expression of proinflammatory genes (iNOS, IL-1β, and COX-2) in LPS-stimulated RAW264.7 cells without cytotoxicity. Ma-ME inhibited NF-κB activation by suppressing signaling molecules such as IκBα, Akt, Src, and Syk. Moreover, the CETSA assay revealed that Ma-ME binds to Syk, the most upstream molecule in the NF-κB signal pathway. Oral administration of Ma-ME not only alleviated inflammatory lesions, but also reduced the gene expression of IL-1β and p-Syk in mice with HCl/EtOH-induced gastritis. HPLC and LC-MS/MS analyses confirmed that Ma-ME contains various anti-inflammatory flavonoids, including quercetin, daidzein, and nevadensin.

CONCLUSIONS

Ma-ME exhibited anti-inflammatory activities in vitro and in vivo by targeting Syk in the NF-κB signaling pathway. Therefore, we propose that Ma-ME could be used to treat inflammatory diseases such as gastritis.

Flavonoids: Potential Candidates for the Treatment of Neurodegenerative Disorders

Neurodegenerative disorders, such as Parkinson's disease (PD), Alzheimer's disease (AD), Amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD), are the most concerning disorders due to the lack of effective therapy and dramatic rise in affected cases. Although these disorders have diverse clinical manifestations, they all share a common cellular stress response. These cellular stress responses including neuroinflammation, oxidative stress, proteotoxicity, and endoplasmic reticulum (ER)-stress, which combats with stress conditions. Environmental stress/toxicity weakened the cellular stress response which results in cell damage. Small molecules, such as flavonoids, could reduce cellular stress and have gained much attention in recent years. Evidence has shown the potential use of flavonoids in several ways, such as antioxidants, anti-inflammatory, and anti-apoptotic, yet their mechanism is still elusive. This review provides an insight into the potential role of flavonoids against cellular stress response that prevent the pathogenesis of neurodegenerative disorders.

Daidzein cocrystals: An opportunity to improve its biopharmaceutical parameters

The present study involves the contribution of cocrystallization towards the modification of the biopharmaceutical parameters of poorly watersoluble plant-originated isoflavone, daidzein (DAID). The cocrystals were prepared with GRAS status coformers i.e., isonicotinamide, theobromine and cytosine using mechanochemical grinding and characterized by various analytical techniques (DSC, FT-IR, PXRD and solid-state NMR). Crystal structures were obtained from PXRD data using BIOVIA Materials Studio software and compared in terms of supramolecular motifs. An additional qualitative and quantitative insight into interactions between both components of the cocrystal illustrated the presence of OH⋯N and OH⋯O=C heterosynthons and revealed a stabilizing role of hydrogen bonding. The cocrystals were further evaluated for their solubility, intrinsic dissolution and in vivo profile. Solubility and dissolution studies of pure daidzein and its cocrystals, namely daidzein-isonicotinamide (DIS), daidzein-cytosine (DCYT) and daidzein-theobromine (DTB) exhibited an almost 2-fold improvement. Evaluation of maximum concentration (Cmax) of cocrystals reveals that the DIS cocrystal shows the highest Cmax of 1848.7 ng/ml followed by DCYT cocrystal (1614.9 ng/ml) and DTB cocrystal (1326.0 ng/ml) in comparison to DAID which has a Cmax 870.5 ng/ml. Each of these cocrystals showed significant enhancement in in vivo and in vitro activities in comparison to daidzein. Thus, this report suggests cocrystallization as a viable approach to resolve the solubility and bioavailability issues that circumvent the use of a therapeutically potential isoflavone, daidzein.

Astrocytes Mediate Protective Actions of Estrogenic Compounds after Traumatic Brain Injury

Traumatic brain injury (TBI) is a serious public health problem. It may result in severe neurological disabilities and in a variety of cellular metabolic alterations for which available therapeutic strategies are limited. In the last decade, the use of estrogenic compounds, which activate protective mechanisms in astrocytes, has been explored as a potential experimental therapeutic approach. Previous works have suggested estradiol (E2) as a neuroprotective hormone that acts in the brain by binding to estrogen receptors (ERs). Several steroidal and nonsteroidal estrogenic compounds can imitate the effects of estradiol on ERs. These include hormonal estrogens, phytoestrogens and synthetic estrogens, such as selective ER modulators or tibolone. Current evidence of the role of astrocytes in mediating protective actions of estrogenic compounds after TBI is reviewed in this paper. We conclude that the use of estrogenic compounds to modulate astrocytic properties is a promising therapeutic approach for the treatment of TBI.

Anti-inflammatory Activity of 8-Hydroxydaidzein in LPS-Stimulated BV2 Microglial Cells via Activation of Nrf2-Antioxidant and Attenuation of Akt/NF-κB-Inflammatory Signaling Pathways, as Well As Inhibition of COX-2 Activity

It was demonstrated that isoflavones can cross the blood-brain barrier, making them desirable candidate agents for the prevention of neurological symptoms. 8-Hydroxydaidzein (8-OHD, 4',7,8-trihydoxyisoflavone) is an isoflavone found only in fermented soy food. Current results showed that 8-OHD inhibited LPS-stimulated production of nitric oxide (NO) and proinflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-6, by inhibiting gene expression in BV2 microglial cells. Moreover, 8-OHD markedly quenched reactive oxygen species (ROS) and activated NF-E2-related factor 2 (Nrf2) so as to upregulate expression of Phase II enzymes, including heme oxygenase (HO)-1, NAD(P)H quinone dehydrogenase 1 (NQO1), and the modifier subunit of glutamate cysteine ligase (GCLM). 8-OHD also suppressed LPS-stimulated phosphorylation of Akt and NF-κB-p65. The anti-inflammatory activity of 8-OHD was attenuated by the HO-1 inhibitor zinc protoporphyrin (Znpp) but augmented by the PI3K/Akt inhibitor LY294002. 8-OHD also diminished LPS-induced prostaglandin E₂ (PGE₂) production without affecting cyclooxygenase (COX)-2 expression. In vitro assay shows that 8-OHD displayed mixed-type inhibition of COX-2 with an IC₅₀ of 8.9 ± 1.2 μM. These data suggest that the anti-inflammatory activity of 8-OHD may be associated with the activation of Nrf2/HO-1 and attenuation of Akt/NF-κB signaling pathways as well as inhibition of COX-2 enzyme activity. In conclusion, 8-OHD, a potent Nrf2 activator, Akt/NF-κB activation suppressor, and COX-2 enzyme inhibitor, may have health-promoting effects for mitigating microglia activation and preventing neuroinflammation.

Involvement of Astrocytes in Alzheimer's Disease from a Neuroinflammatory and Oxidative Stress Perspective

Alzheimer disease (AD) is a frequent and devastating neurodegenerative disease in humans, but still no curative treatment has been developed. Although many explicative theories have been proposed, precise pathophysiological mechanisms are unknown. Due to the importance of astrocytes in brain homeostasis they have become interesting targets for the study of AD. Changes in astrocyte function have been observed in brains from individuals with AD, as well as in AD in vitro and in vivo animal models. The presence of amyloid beta (Aβ) has been shown to disrupt gliotransmission, neurotransmitter uptake, and alter calcium signaling in astrocytes. Furthermore, astrocytes express apolipoprotein E and are involved in the production, degradation and removal of Aβ. As well, changes in astrocytes that precede other pathological characteristics observed in AD, point to an early contribution of astroglia in this disease. Astrocytes participate in the inflammatory/immune responses of the central nervous system. The presence of Aβ activates different cell receptors and intracellular signaling pathways, mainly the advanced glycation end products receptor/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway, responsible for the transcription of pro-inflammatory cytokines and chemokines in astrocytes. The release of these pro-inflammatory agents may induce cellular damage or even stimulate the production of Aβ in astrocytes. Additionally, Aβ induces the appearance of oxidative stress (OS) and production of reactive oxygen species and reactive nitrogen species in astrocytes, affecting among others, intracellular calcium levels, NADPH oxidase (NOX), NF-κB signaling, glutamate uptake (increasing the risk of excitotoxicity) and mitochondrial function. Excessive neuroinflammation and OS are observed in AD, and astrocytes seem to be involved in both. The Aβ/NF-κB interaction in astrocytes may play a central role in these inflammatory and OS changes present in AD. In this paper, we also discuss therapeutic measures highlighting the importance of astrocytes in AD pathology. Several new therapeutic approaches involving phenols (curcumin), phytoestrogens (genistein), neuroesteroids and other natural phytochemicals have been explored in astrocytes, obtaining some promising results regarding cognitive improvements and attenuation of neuroinflammation. Novel strategies comprising astrocytes and aimed to reduce OS in AD have also been proposed. These include estrogen receptor agonists (pelargonidin), Bambusae concretio Salicea, Monascin, and various antioxidatives such as resveratrol, tocotrienol, anthocyanins, and epicatechin, showing beneficial effects in AD models.

Cancer chemoprevention revisited: Cytochrome P450 family 1B1 as a target in the tumor and the microenvironment

Cancer chemoprevention is the use of synthetic, natural or biological agents to prevent or delay the development or progression of malignancies. Intriguingly, many phytochemicals with anti-inflammatory and anti-angiogenic effects, recently proposed as chemoprevention strategies, are inhibitors of Cytochrome P450 family 1B1 (CYP1B1), an enzyme overexpressed in a wide variety of tumors and associated with angiogenesis. In turn, pro-inflammatory cytokines were reported to boost CYP1B1 expression, suggesting a key role of CYP1B1 in a positive loop of inflammatory angiogenesis. Other well-known pro-tumorigenic activities of CYP1B1 rely on metabolic bioactivation of xenobiotics and steroid hormones into their carcinogenic derivatives. In contrast to initial in vitro observations, in vivo studies demonstrated a protecting role against cancer for the other CYP1 family members (CYP1A1 and CYP1A2), suggesting that the specificity of CYP1 family inhibitors should be carefully taken into account for developing potential chemoprevention strategies. Recent studies also proposed a role of CYP1B1 in multiple cell types found within the tumor microenvironment, including fibroblasts, endothelial and immune cells. Overall, our review of the current literature suggests a positive loop between inflammatory cytokines and CYP1B1, which in turn may play a key role in cancer angiogenesis, acting on both cancer cells and the tumor microenvironment. Strategies aiming at specific CYP1B1 inhibition in multiple cell types may translate into clinical chemoprevention and angioprevention approaches.

Inhibitory potential of some Romanian medicinal plants against enzymes linked to neurodegenerative diseases and their antioxidant activity

CONTEXT

Eryngium planum, Geum urbanum and Cnicus benedictus plants are an endemic botanical from the Romanian used in folk medicine.

OBJECTIVE

The extracts from three Romanian medicinal plants were investigated for their possible neuroprotective potential.

MATERIALS AND METHODS

Within this study, in vitro neuroprotective activity of the extracts of E. planum, G. urbanum, and C. benedictus plants were investigated via inhibition of acetylcholinesterase (AChE) and tyrosinase (TYR). Total content of phenolics, flavonoids, and proanthocyanidins, high-performance liquid chromatography profile of the main phenolic compounds and antioxidant activity were also determined.

RESULTS

Among the tested extracts, the best inhibition of AChE (88.76 ± 5.2%) and TYR (88.5 ± 5.2%) was caused by C. benedictus ethanol (EtOH) extract. The G. urbanum extracts exerted remarkable scavenging effect against 2, 2-diphenyl-1-picrylhydrazyl (IC50, 7.8 ± 0.5 μg/mL aqueous extract, and IC50, 1.3 ± 0.1 μg/mL EtOH extract, respectively) and reducing power, whereas the EtOH extract of C. benedictus showed high scavenging activity (IC50, 0.609 ± 0.04 mg/mL), also.

CONCLUSION

According to our knowledge, this is the first study that demonstrates in vitro neuroprotective effects of E. planum, G. urbanum and C. benedictus.

Phytoestrogens and cognitive function: a review

Neuroprotective effects of phytoestrogen compounds (found in soy) have been demonstrated in animal research and cell culture studies. In particular, phytoestrogens have been shown to reduce Alzheimer's Disease (AD) related pathology, potentially alleviating risk of AD progression. In addition to their antioxidant properties, soy products also have the ability to affect cognition via interaction with estrogen receptors. However, observational studies and randomised controlled trials in humans have resulted in inconclusive findings within this domain. There are several possible reasons for these discrepant data. Studies which report no effect of phytoestrogens on cognition have mainly been carried out in European cohorts, with an average low dietary consumption. In contrast, investigation of Asian populations, with a higher general intake of tofu (a non-fermented soy product) have shown negative associations with cognitive function in those over the age of 65. Consideration of type of soy product is important, as in the latter sample, protective effects of tempe (fermented soy) were also observed. Limited data provide evidence that effects of phytoestrogens on cognition may be modified by dosage, duration of consumption and cognitive test used. Additionally, characteristics of the study population including age, gender, ethnicity and menopausal status appear to be mediating variables. Phytoestrogen treatment interventions have also shown time-limited positive effects on cognition. These findings are consistent with estrogen treatment studies, where initial positive short-term cognitive effects may occur, which reverse with long-term continuous use in elderly women. Well controlled, large scale studies are needed to assess the effects of phytoestrogens on the aging brain and provide further understanding of this association.

Involvement of interleukin-1β in the autophagic process of microglia: relevance to Alzheimer's disease

BACKGROUND

Autophagy is a major pathway of protein and organelle degradation in the lysosome. Autophagy exists at basal constitutive level and can be induced as a defense mechanism under stress conditions. Molecular relationships between autophagy and inflammation at the periphery were recently evidenced, highlighting a role of autophagy in the regulation of inflammation. Impairment of autophagy (with accumulation of autophagic vacuoles) and substantial inflammation are found in neurodegenerative diseases such as Alzheimer's Disease (AD). However, the links between autophagy and inflammation in AD remain to be determined.

METHODS

Here, we examined the inflammatory reaction and autophagy in murine tri-cultures of neurons, astrocytes, and microglia. Tri-cultures were exposed to various inflammatory stresses (lipopolysaccharide (LPS), amyloid peptide (Aβ42) with or without cytokines) for 48 hours. Furthermore, the relationships between inflammation and autophagy were also analyzed in astrocyte- and microglia-enriched cultures. Data for multiple variable comparisons were analyzed by a one-way ANOVA followed by a Newman-keuls' test.

RESULTS

Aβ42 induced a low inflammation without accumulation of acidic vesicles contrary to moderate or severe inflammation induced by LPS or the cytokine cocktail (IL-1β, TNF-α, and IL-6) or IL-1β alone which led to co-localization of p62 and LC3, two markers of autophagy, with acidic vesicles stained with Lyso-ID Red dye. Moreover, the study reveals a major role of IL-1β in the induction of autophagy in tri-cultures in the presence or absence of Aβ42. However, the vulnerability of the autophagic process in purified microglia to IL-1β was prevented by Aβ42.

CONCLUSION

These findings show a close relationship between inflammation and autophagy, in particular a major role of IL-1β in the induction of the microglial autophagy which could be the case in AD. New therapeutic strategies could target inflammasome and autophagy in microglia to maintain its role in the amyloid immunosurveillance.

Akebia Saponin D attenuates amyloid β-induced cognitive deficits and inflammatory response in rats: involvement of Akt/NF-κB pathway

Neuroinflammatory responses caused by amyloid β(Aβ) play an important role in the pathogenesis of Alzheimer's disease (AD). Aβ is known to be directly responsible for the activation of glial cells and induction of apoptosis. Akebia Saponin D (ASD) is extracted from a traditional herbal medicine Dipsacus asper Wall, which has been shown to protect against ibotenic acid-induced cognitive deficits and cell death in rats. In this study, we investigated the in vivo protective effect of ASD on learning and memory impairment induced by bilateral intracerebroventricular injections of Aβ1-42 using Morris water and Y-maze task. Furthermore, the anti-inflammatory activity and neuroprotective effect of ASD was examined with methods of histochemistry and biochemistry. These data showed that oral gavage with ASD at doses of 30, 90 and 270 mg/kg for 4 weeks exerted an improved effect on cognitive impairment. Subsequently, the ASD inhibited the activation of glial cells and the expression of tumor necrosis factor (TNF)-α, interleukin-1 beta (IL-1β) and cyclooxygenase-2 (COX-2) in rat brain. Moreover, ASD afforded beneficial actions on inhibitions of Akt and IκB kinase (IKK) phosphorylations, as well as nuclear factor κB (NF-κB) activation induced by Aβ1-42. These results suggest that ASD may be a potential agent for suppressing both Alzheimer's disease-related neuroinflammation and memory system dysfunction.

Daidzein improves insulin resistance in ovariectomized rats

OBJECTIVE

To determine whether daidzein improves insulin resistance by modifying weight gain, visceral fat accumulation, blood lipids and serum cytokines levels in ovariectomized Sprague-Dawley rats.

MATERIALS AND METHODS

Twenty-eight 12-week-old female rats were divided into three groups: the sham-operated group (SHAM) (n =10), the ovariectomized group receiving daidzein therapy (DAID) (n =10), and the ovariectomized control group (Control) (n =8). The rats in the DAID group received 50 mg/kg daidzein via gavage daily. Weight and food intake were recorded every 2 weeks. All of the animals were euthanized 12 weeks after ovariectomy, after which their fasting insulin, glucose, blood lipids, estradiol, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), adiponectin and leptin levels were measured.

RESULTS

After 12 weeks, the ovariectomized rats demonstrated an increase in their body weight and visceral fat; compared to the SHAM rats, the ovariectomized rats also experienced a significant increase in their serum IL-6 levels and insulin resistance, which was calculated using the homeostatic model assessment of insulin resistance (HOMA-IR) (p <0.05). Daidzein therapy decreased weight gain, visceral fat, the HOMA-IR index and IL-6 levels that were induced by ovariectomy. Rats which had received daidzein therapy had lower levels of TNF-α, leptin and blood lipids (except for high density lipoprotein cholesterol) than the other two groups. IL-6 levels positively correlated with the HOMA-IR index in all of the rats after adjustment for body weight (r =0.495; p =0.016).

CONCLUSION

We conclude that daidzein can improve insulin resistance induced by ovariectomy by decreasing weight gain, visceral fat accumulation, blood lipids, TNF-α, leptin and IL-6 levels.

Neuroinflammation: modulation by flavonoids and mechanisms of action

Neuroinflammatory processes are known to contribute to the cascade of events culminating in the neuronal damage that underpins neurodegenerative disorders such as Parkinson's and Alzheimer's disease. Recently, there has been much interest in the potential neuroprotective effects of flavonoids, a group of plant secondary metabolites known to have diverse biological activity in vivo. With respect to the brain, flavonoids, such as those found in cocoa, tea, berries and citrus, have been shown to be highly effective in preventing age-related cognitive decline and neurodegeneration in both animals and humans. Evidence suggests that flavonoids may express such ability through a multitude of physiological functions, including an ability to modulate the brains immune system. This review will highlight the evidence for their potential to inhibit neuroinflammation through an attenuation of microglial activation and associated cytokine release, iNOS expression, nitric oxide production and NADPH oxidase activity. We will also detail the current evidence indicting that their regulation of these immune events appear to be mediated by their actions on intracellular signaling pathways, including the nuclear factor-κB (NF-κB) cascade and mitogen-activated protein kinase (MAPK) pathway. As such, flavonoids represent important precursor molecules in the quest to develop of a new generation of drugs capable of counteracting neuroinflammation and neurodegenerative disease.

Astrocytes and microglia: responses to neuropathological conditions

Activated astrocytes and microglia, hallmark of neurodegenerative diseases release different factors like array of pro and anti-inflammatory cytokines, free radicals, anti-oxidants, and neurotrophic factors during neurodegeneration which further contribute to neuronal death as well as in survival mechanisms. Astrocytes act as double-edged sword exerting both detrimental and neuroprotective effects while microglial cells are attributed more in neurodegenerative mechanisms. The dual and insufficient knowledge about the precise role of glia in neurodegeneration showed the need for further investigations and thorough review of the function of glia in neurodegeneration. In this review, we consolidate and categorize the glia-released factors which contribute in degenerative and protective mechanisms during neuropathological conditions.

Prevention of the β-amyloid peptide-induced inflammatory process by inhibition of double-stranded RNA-dependent protein kinase in primary murine mixed co-cultures

Background

Inflammation may be involved in the pathogenesis of Alzheimer's disease (AD). There has been little success with anti-inflammatory drugs in AD, while the promise of anti-inflammatory treatment is more evident in experimental models. A new anti-inflammatory strategy requires a better understanding of molecular mechanisms. Among the plethora of signaling pathways activated by β-amyloid (Aβ) peptides, the nuclear factor-kappa B (NF-κB) pathway could be an interesting target. In virus-infected cells, double-stranded RNA-dependent protein kinase (PKR) controls the NF-κB signaling pathway. It is well-known that PKR is activated in AD. This led us to study the effect of a specific inhibitor of PKR on the Aβ42-induced inflammatory response in primary mixed murine co-cultures, allowing interactions between neurons, astrocytes and microglia.

Methods

Primary mixed murine co-cultures were prepared in three steps: a primary culture of astrocytes and microglia for 14 days, then a primary culture of neurons and astrocytes which were cultured with microglia purified from the first culture. Before exposure to Aβ neurotoxicity (72 h), co-cultures were treated with compound C16, a specific inhibitor of PKR. Levels of tumor necrosis factor-α (TNFα), interleukin (IL)-1β, and IL-6 were assessed by ELISA. Levels of P_T451-PKR and activation of IκB, NF-κB and caspase-3 were assessed by western blotting. Apoptosis was also followed using annexin V-FITC immunostaining kit. Subcellular distribution of P_T451-PKR was assessed by confocal immunofluorescence and morphological structure of cells by scanning electron microscopy. Data were analysed using one-way ANOVA followed by a Newman-Keuls' post hoc test

Results

In these co-cultures, PKR inhibition prevented Aβ42-induced activation of IκB and NF-κB, strongly decreased production and release of tumor necrosis factor (TNFα) and interleukin (IL)-1β, and limited apoptosis.

Conclusion

In spite of the complexity of the innate immune response, PKR inhibition could be an interesting anti-inflammatory strategy in AD.

Daidzein regulates secretion, production and gene expression of mucin from airway epithelial cells stimulated by proinflammatory factor and growth factor

In this study, we investigated whether daidzein significantly affects secretion, production and gene expression of mucin from cultured airway epithelial cells. Confluent primary rat tracheal surface epithelial (RTSE) cells were pretreated with adenosine triphosphate (ATP) for 5 min and then chased for 30 min in the presence of daidzein to assess the effect on mucin secretion using ELISA. At the same time, confluent NCI-H292 cells were pretreated with daidzein for 30 min and then stimulated with EGF and PMA for 24 h, respectively. The MUC5AC mucin gene expression and mucin protein production were measured by RT-PCR and ELISA. The results were as follows: (1) daidzein significantly decreased ATP-induced mucin secretion from cultured RTSE cells; (2) daidzein inhibited the production of MUC5AC mucin protein induced by EGF or PMA from NCI-H292 cells; (3) daidzein also inhibited the expression of MUC5AC mucin gene induced by EGF or PMA from NCI-H292 cells. This result suggests that daidzein can regulate secretion, production and gene expression of mucin, by directly acting on airway epithelial cells.