Beneficial effect of Eucommia polysaccharides on systemic lupus erythematosus-like syndrome induced by Campylobacter jejuni in BALB/c mice

Preparation techniques, structural features, and bioactivities of Eucommia ulmoides polysaccharides: A review

Eucommia ulmoides Oliv. (tu-chung), as a famous nature medical and edible plant, has the effect of tonifying liver and kidney, strengthening the function of the muscles and bones, and miscarriage prevention. Accumulating evidence has demonstrated that the polysaccharides from Eucommia ulmoides Oliv. (EUPs) are a kind of vital and representative biologically active macromolecules and have various health-promoting biological activities in vivo and in vitro, such as antioxidant activity, immunomodulatory activity, hypolipidemic and hypoglycemic activities, anti-inflammatory activities, anti-tumor activity, and among others. The review aims to comprehensively and systematically collate the recent research progress on extraction and purification methods, structural characteristics, biological activities, mechanism of action, structural modification, and toxicity of EUPs to support their therapeutic potential and health-care functions. New valuable insights for future research with EUPs were also proposed in the areas of structural characterization and pharmacological activities to promoting the development of therapeutic agents and functional foods.

Insights into the promising prospect of medicinal chemistry studies against neurodegenerative disorders

Medicinal chemistry is an interdisciplinary field that incorporates organic chemistry, biochemistry, physical chemistry, pharmacology, informatics, molecular biology, structural biology, cell biology, and other disciplines. Additionally, it considers molecular factors such as the mode of action of the drugs, their chemical structure-activity relationship (SAR), and pharmacokinetic aspects like absorption, distribution, metabolism, elimination, and toxicity. Neurodegenerative disorders (NDs), which are defined by the breakdown of neurons over time, are affecting an increasing number of people. Oxidative stress, particularly the increased production of Reactive Oxygen Species (ROS), plays a crucial role in the growth of various disorders, as indicated by the identification of protein, lipid, and Deoxyribonucleic acid (DNA) oxidation products in vivo. Because of their inherent nature, most biological molecules are vulnerable to ROS, even if they play a role in metabolic parameters and cell signaling. Due to their high polyunsaturated fatty acid content, low antioxidant barrier, and high oxygen uptake, neurons are particularly vulnerable to oxidation by nature. As a result, excessive ROS generation in neurons looks especially harmful, and the mechanisms associated with biomolecule oxidative destruction are several and complex. This review focuses on the formation and management of ROS, as well as their chemical characteristics (both thermodynamic and kinetic), interactions, and implications in NDs.

Influences of dietary Eucommia ulmoides leaf extract on the hepatic lipid metabolism, inflammation response, intestinal antioxidant capacity, intestinal microbiota, and disease resistance of the channel catfish (Ictalurus punctatus)

The purpose of the study was to investigate the effects of Eucommia ulmoides leaf extract (ELE) on the common occurrence of liver steatosis, chronic inflammation, oxidative stress, disturbance of gut microbiota, and disease susceptibility in high-fat diet-fed channel catfish. Channel catfish fed three diets, including a high-fat diet (11% crude fat) and ELE-supplemented diets containing 1‰ or 2‰ ELE for 4 weeks. The results showed the contents of liver triacylglycerol of 1‰ and 2‰ ELE groups were reduced, and ELE treatments decreased the expression of lipogenesis related genes (srebp-1c, pparγ, and acc-1), and increased the expression of lipolysis related genes (pparα). In addition, the supplementation of ELE improved the inflammatory response of the liver and intestine. ELE could improve the destruction of intestinal morphology structure and increase the expression level of hif-1a and tight junction proteins (Occludin, Claudin2, Claudin15). 2‰ ELE significantly enhanced the antioxidant capacity of intestine by increasing the activity of SOD enzyme. Moreover, the supplement of ELE significantly increased the abundance of Cetobacterium and Romboutsia (p < 0.05). Compared with the control group, the expression of immune factor nf-κb had a significant decrease, and il-1β showed a tendency to decrease in the ELE supplement groups after pathogenic bacteria challenge. In conclusion, the ELE alleviated fatty liver disease and inflammation response, improved the oxidative capacity and physiological structure of intestine, and improved the structure of intestinal microbiota and disease resistance in HFD-fed channel catfish.

Bacterial infections in lupus: Roles in promoting immune activation and in pathogenesis of the disease

BACKGROUND

Bacterial infections of the lung, skin, bloodstream and other tissues are common in patients with systemic lupus erythematosus (lupus) and are often more severe and invasive than similar infections in control populations. A variety of studies have explored the changes in bacterial abundance in lupus patients, the rates of infection and the influence of particular bacterial species on disease progression, using both human patient samples and mouse models of lupus.

OBJECTIVE

The aim of this review is to summarize human and mouse studies that describe changes in the bacterial microbiome in lupus, the role of a leaky gut in stimulating inflammation, identification of specific bacterial species associated with lupus, and the potential roles of certain common bacterial infections in promoting lupus progression.

METHODS

Information was collected using searches of the Pubmed database for articles relevant to bacterial infections in lupus and to microbiome changes associated with lupus.

RESULTS

The reviewed studies demonstrate significant changes in the bacterial microbiome of lupus patients as compared to control subjects and in lupus-prone mice compared to control mice. Furthermore, there is evidence supporting the existence of a leaky gut in lupus patients and in lupus-prone mice. This leaky gut may allow live bacteria or bacterial components to enter the circulation and cause inflammation. Invasive bacterial infections are more common and often more severe in lupus patients. These include infections caused by Staphylococcus aureus, Salmonella enterica, Escherichia coli, Streptococcus pneumoniae and mycobacteria. These bacterial infections can trigger increased immune activation and inflammation, potentially stimulating activation of autoreactive lymphocytes and leading to worsening of lupus symptoms.

CONCLUSIONS

Together, the evidence suggests that lupus predisposes to infection, while infection may trigger worsening lupus, leading to a feedback loop that may reinforce autoimmune symptoms.

Structural characterization and anticomplement activity of an acidic polysaccharide from Hedyotis diffusa

An acidic homogeneous polysaccharide (HD-PS-1) was purified from Hedyotis diffusa (Willd.) Roxb. HD-PS-1 possessed a backbone chain of →[4)-β-Glcp-3-OAc-(1]₆→[6)-β-Manp-(1]₂→6)-α-Galp-(1→[4)-α-Galp-(1]₂→, with three branches of β-Manp-(1→3)-β-GlcpA, α-Rhap-(1→3)-α-Rhap and α-Galp attached to the backbone chain at O-4 position of 1,4,6-linked β-Manp, O-3 position of 1,3,6-linked α-Galp and O-3 position of 1,3,4-linked α-Galp, respectively. HD-PS-1 exhibited significant anticomplement activity (CH₅₀: 0.084 ± 0.009 mg/mL, AP₅₀: 0.176 ± 0.013 mg/mL). It was found that the presence of uronic acids is important to anticomplement activity of HD-PS-1, given that the reduced HD-PS-1 showed weaker activity (CH₅₀: 0.456 ± 0.008 mg/mL, AP₅₀: 0.572 ± 0.010 mg/mL). Preliminary mechanism study indicated that HD-PS-1 interacted with C3 and C4 in the complement activation cascade. In addition, a neutral homogeneous polysaccharide (HD-PS-2) was also purified and characterized. HD-PS-2 displayed antioxidant activity by scavenging DPPH· radicals without anticomplement activity.

The Anti-Inflammatory Activity of Eucommia ulmoides Oliv. Bark. Involves NF-κB Suppression and Nrf2-Dependent HO-1 Induction in BV-2 Microglial Cells

In the present study, we investigated the anti-inflammatory properties of Eucommia ulmoides Oliv. Bark. (EUE) in lipopolysaccharide (LPS)-stimulated microglial BV-2 cells and found that EUE inhibited LPS-mediated up-regulation of pro-inflammatory response factors. In addition, EUE inhibited the elevated production of pro-inflammatory cytokines, mediators, and reactive oxygen species (ROS) in LPS-stimulated BV-2 microglial cells. Subsequent mechanistic studies revealed that EUE suppressed LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs), phosphoinositide-3-kinase (PI3K)/Akt, glycogen synthase kinase-3β (GSK-3β), and their downstream transcription factor, nuclear factor-kappa B (NF-κB). EUE also blocked the nuclear translocation of NF-κB and inhibited its binding to DNA. We next demonstrated that EUE induced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and upregulated heme oxygenase-1 (HO-1) expression. We determined that the significant up-regulation of HO-1 expression by EUE was a consequence of Nrf2 nuclear translocation; furthermore, EUE increased the DNA binding of Nrf2. In contrast, zinc protoporphyrin (ZnPP), a specific HO-1 inhibitor, blocked the ability of EUE to inhibit NO and PGE₂ production, indicating the vital role of HO-1. Overall, our results indicate that EUE inhibits pro-inflammatory responses by modulating MAPKs, PI3K/Akt, and GSK-3β, consequently suppressing NF-κB activation and inducing Nrf2-dependent HO-1 activation.

Phytochemicals that regulate neurodegenerative disease by targeting neurotrophins: a comprehensive review

Alzheimer's disease (AD), characterized by progressive dementia and deterioration of cognitive function, is an unsolved social and medical problem. Age, nutrition, and toxins are the most common causes of AD. However, currently no credible treatment is available for AD. Traditional herbs and phytochemicals may delay its onset and slow its progression and also allow recovery by targeting multiple pathological causes by antioxidative, anti-inflammatory, and antiamyloidogenic properties. They also regulate mitochondrial stress, apoptotic factors, free radical scavenging system, and neurotrophic factors. Neurotrophins such as BDNF, NGF, NT3, and NT4/5 play a vital role in neuronal and nonneuronal responses to AD. Neurotrophins depletion accelerates the progression of AD and therefore, replacing such neurotrophins may be a potential treatment for neurodegenerative disease. Here, we review the phytochemicals that mediate the signaling pathways involved in neuroprotection specifically neurotrophin-mediated activation of Trk receptors and members of p75(NTR) superfamily. We focus on representative phenolic derivatives, iridoid glycosides, terpenoids, alkaloids, and steroidal saponins as regulators of neurotrophin-mediated neuroprotection. Although these phytochemicals have attracted attention owing to their in vitro neurotrophin potentiating activity, their in vivo and clinical efficacy trials has yet to be established. Therefore, further research is necessary to prove the neuroprotective effects in preclinical models and in humans.

Eucommia ulmoides Oliv. bark. attenuates 6-hydroxydopamine-induced neuronal cell death through inhibition of oxidative stress in SH-SY5Y cells

ETHNOPHARMACOLOGICAL RELEVANCE

Eucommia ulmoides Oliv. Bark. (EUE) has commonly been used to fortify the muscles and lungs, lower blood pressure, prevent miscarriage, improve liver and kidney tone, and promote longevity as a traditional tonic medicine in Korea, China, and Japan.

AIM OF THE STUDY

In this study, we investigated the mechanisms by which EUE protects neuronal cells from apoptosis induced by the Parkinson's disease (PD)-related neurotoxin, 6-hydroxydopamine (6-OHDA).

MATERIALS AND METHODS

We determined the neuroprotective effects of EUE on 6-OHDA-induced neuronal cell death, cytotoxicity, reactive oxygen species (ROS) production, and mitochondrial membrane dysfunction. Moreover, we examined whether EUE suppressed phosphorylation of c-Jun N-terminal kinase (JNK), phosphatidylinositol 3-kinase (PI3K)/Akt, and glycogen synthase kinase-3 beta (GSK-3β). Furthermore, the neuroprotective effects of EUE on 6-OHDA-induced activation of nuclear factor-kappa B (NF-κB) was studied in SH-SY5Y cells.

RESULTS

Pretreatment of SH-SY5Y cells with EUE significantly reduced 6-OHDA-induced cell death and cytotoxicity. EUE inhibited 6-OHDA-induced generation of ROS, which conferred cytoprotection against 6-OHDA-induced oxidative injury. EUE treatment also strikingly inhibited 6-OHDA-induced mitochondrial dysfunction. In addition, EUE suppressed phosphorylation of JNK, PI3K/Akt, and GSK-3β. Furthermore, EUE blocked 6-OHDA-induced NF-κB nuclear translocation, an event downstream from JNK, PI3K/Akt, and GSK-3β phosphorylation. Moreover, chlorogenic acid (CGA), one of the active constituents of EUE, was also able to reduce 6-OHDA-induced toxicity in SH-SY5Y cells.

CONCLUSION

Taken together, these results suggest that EUE attenuates oxidative stress through activation of JNK, PI3K/Akt, GSK-3β, and NF-κB pathways, thereby protecting cells from neuronal cell death.

Is there an unrecognised role for Campylobacter infections in (chronic) inflammatory diseases?

Campylobacter species are one of the major causes of global bacterial-related diarrheal disease worldwide. The disease is most frequently associated with the ingestion of contaminated meat, raw milk, pets, contaminated water, and the organism may be frequently cultured from the faeces of chicken and other domesticated farm animals. Of the 17 established Campylobacter species, the most important pathogens for humans are Campylobacter jejuni (C. jejuni), Campylobacter coli (C. coli) and Campylobacter fetus (C. fetus), which are all associated with diarrheal disease. Further, C. jejuni and C. coli are also associated with the neuroparalytic diseases Guillain-Barré syndrome and Miller Fischer syndrome, respectively, whereas C. fetus is linked with psoriatic arthritis. The discovery of both “molecular mimicry” and translocation-related virulence in the pathogenesis of C. jejuni-induced disease, indicates that Campylobacter-related gastrointestinal infections may not only generate localized, acute intestinal infection in the human host, but may also be involved in the establishment of chronic inflammatory diseases. Indeed, pathogenicity studies on several Campylobacter species now suggest that molecular mimicry and translocation-related virulence is not only related to C. jejuni, but may play a role in human disease caused by other Campylobacter spp. In this review, the authors provide a review based on the current literature describing the potential links between Campylobacter spp. and (chronic) inflammatory diseases, and provide their opinions on the likely role of Campylobacter in such diseases.

Eucommia ulmoides Oliv. Bark. protects against hydrogen peroxide-induced neuronal cell death in SH-SY5Y cells

ETHNOPHARMACOLOGICAL RELEVANCE

Eucommia ulmoides Oliv. Bark. (EUE), has commonly been used to fortify the muscles and lungs, lower blood pressure, prevent miscarriage, improve the tone of liver and kidneys, and promote longevity the traditional tonic medicines of Korea, China, and Japan.

AIM OF THE STUDY

In this study, we investigated that the neuroprotective activities and possible mechanisms of EUE aqueous extract in hydrogen peroxide (H(2)O(2))-induced neuronal cell death in human SH-SY5Y neuroblastoma cells.

MATERIAL AND METHOD

We examined the effects of EUE against H(2)O(2)-induced cytotoxicity, DNA condensation, the production of reactive oxygen species (ROS), loss of mitochondria membrane potential (MMP), the proteolysis of cleaved poly-ADP-ribose polymerase (PARP), and the expression of Bcl-2, Bcl-xL, cleaved caspase-3, and release of cytochrome c. Moreover, we attempted to determine whether EUE suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase 1/2 (ERK 1/2), and phosphoinositide 3-kinase (PI3K)/Akt.

RESULTS

Pretreatment with EUE increased cell viability and inhibited cytotoxicity and DNA condensation. EUE also attenuated the increase in ROS production and MMP reduction. Western blot data revealed that EUE inhibited H(2)O(2)-induced up- or down-regulation of cleaved PARP, cleaved caspase-3, Bcl-2, and Bcl-xL. The EUE inhibited release of cytochrome c from mitochondria to the cytosol, and significantly attenuated H(2)O(2)-induced phosphorylation of JNK, p38 MAPK, ERK 1/2, and PI3K/Akt.

CONCLUSION

The potent neuroprotective capacity of EUE, shown in these experiments, may potentially be applied in the prevention or treatment of neurodegenerative diseases such as Alzheimer's disease (AD).