Low-molecular weight fractions of Japanese soy sauce act as a RAGE antagonist via inhibition of RAGE trafficking to lipid rafts

Systems pharmacology-based mechanism exploration of Acanthopanax senticosusin for Alzheimer's disease using UPLC-Q-TOF-MS, network analysis, and experimental validation

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease, characterized by progressive cognitive dysfunction and memory loss. However, the disease-modifying treatments for AD are still lacking. Traditional Chinese herbs, have shown their potentials as novel treatments for complex diseases, such as AD.

PURPOSE

This study was aimed at investigating the mechanism of action (MOA) of Acanthopanax senticosusin (AS) for treatment of AD.

METHODS

In this study, we firstly identified the chemical constituents in Acanthopanax senticosusin (AS) utilizing ultra-high performance liquid chromatography coupled with Q-TOF-mass spectrometry (UPLC-Q-TOF-MS), and next built the drug-target network of these compounds. We next performed the systems pharmacology-based analysis to preliminary explore the MOA of AS against AD. Moreover, we applied the network proximity approach to identify the potential anti-AD components in AS. Finally, experimental validations, including animal behavior test, ELISA and TUNEL staining, were conducted to verify our systems pharmacology-based analysis.

RESULTS

60 chemical constituents in AS were identified via the UPLC-Q-TOF-MS approach. The systems pharmacology-based analysis indicated that AS might exert its therapeutic effects on AD via acetylcholinesterase and apoptosis signaling pathway. To explore the material basis of AS against AD, we further identified 15 potential anti-AD components in AS. Consistently, in vivo experiments demonstrated that AS could protect cholinergic nervous system damage and decrease neuronal apoptosis caused by scopolamine.

CONCLUSION

Overall, this study applied systems pharmacology approach, via UPLC-Q-TOF-MS, network analysis, and experimental validation to decipher the potential molecular mechanism of AS against AD.

Glycation reaction and the role of the receptor for advanced glycation end-products in immunity and social behavior

The receptor for advanced glycation end-products (receptor for AGEs, RAGE) is a pattern recognition receptor. The interaction of RAGE with its ligands, such as AGEs, S100 proteins, high mobility group box-1 (HMGB1), and lipopolysaccharides (LPS), is known to play a pivotal role in the propagation of immune responses and inflammatory reactions. The ligand-RAGE interaction elicits cellular responses, for example, in myeloid and lymphoid cells, through distinct pathways by activating NF-κB and Rac1/cdc42, which lead to cytokine production, cell migration, phagocytosis, maturation, and polarization. Recently, oxytocin, a peptide hormone and neuropeptide, was identified as a novel binding molecule for the RAGE; however, it cannot compete with the interaction of RAGE with other ligands or induce RAGE intracellular signaling. The RAGE transports oxytocin from the blood into the brain and regulates brain functions. In this review, we summarize the current understanding of glycation reaction, AGEs, and the RAGE-mediated biological responses as well as the physiological role of RAGE in immunity and social behaviors, particularly, maternal bonding.

Role and Mechanisms of RAGE-Ligand Complexes and RAGE-Inhibitors in Cancer Progression

Interactions of the receptor for advanced glycation end product (RAGE) and its ligands in the context of their role in diabetes mellitus, inflammation, and carcinogenesis have been extensively investigated. This review focuses on the role of RAGE-ligands and anti-RAGE drugs capable of controlling cancer progression. Different studies have demonstrated interaction of RAGE with a diverse range of acidic (negatively charged) ligands such as advanced glycation end products (AGEs), high-mobility group box1 (HMGB1), and S100s, and their importance to cancer progression. Some RAGE-ligands displayed effects on anti- and pro-apoptotic proteins through upregulation of the phosphatidylinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), mitogen-activated protein kinases (MAPKs), matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), and nuclear factor kappa B (NF-κB) pathways, while downregulating p53 in cancer progression. In addition, RAGE may undergo ligand-driven multimodal dimerization or oligomerization mediated through self-association of some of its subunits. We conclude our review by proposing possible future lines of study that could result in control of cancer progression through RAGE inhibition.

Regulatory landscape of AGE-RAGE-oxidative stress axis and its modulation by PPARγ activation in high fructose diet-induced metabolic syndrome

Background

The AGE-RAGE-oxidative stress (AROS) axis is involved in the onset and progression of metabolic syndrome induced by a high-fructose diet (HFD). PPARγ activation is known to modulate metabolic syndrome; however a systems-level investigation looking at the protective effects of PPARγ activation as related to the AROS axis has not been performed.

The aim of this work is to simultaneously characterize multiple molecular parameters within the AROS axis, using samples taken from different body fluids and tissues of a rat model of HFD-induced metabolic syndrome, in the presence or absence of a PPARγ agonist, Rosiglitazone (RGZ).

Methods

Rats were fed with 60% HFD for the first half of the treatment duration (21 days) then continued with either HFD alone or HFD plus RGZ for the second half.

Results

Rats receiving HFD alone showed metabolic syndrome manifestations including hypertension, dyslipidemia, increased glucose levels and insulin resistance, as well as abnormal kidney and inflammatory parameters. Systolic blood pressure, plasma triglyceride and glucose levels, plasma creatinine, and albuminuria were significantly improved in the presence of RGZ. The following molecular parameters of the AROS axis were significantly upregulated in our rat model: carboxymethyl lysine (CML) in urine and liver; carboxyethyl lysine (CEL) in urine; advanced glycation end products (AGEs) in plasma; receptor for advanced glycation end products (RAGE) in liver and kidney; advanced oxidation protein products (AOPP) in plasma; and 4-hydroxynonenal (HNE) in plasma, liver, and kidney. Conversely, with RGZ administration, the upregulation of AOPP and AGEs in plasma, CML and CEL in urine, RAGE in liver as well as HNE in plasma and liver was significantly counteracted/prevented.

Conclusions

Our data demonstrate (i) the systems-level regulatory landscape of HFD-induced metabolic syndrome involving multiple molecular parameters, including HNE, AGEs and their receptor RAGE, and (ii) attenuation of metabolic syndrome by PPARγ modulation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-016-0149-z) contains supplementary material, which is available to authorized users.

Inhibitory actions of selected natural substances on formation of advanced glycation endproducts and advanced oxidation protein products

Background

Advanced glycation endproducts (AGE) and advanced oxidation protein products (AOPP) arise as a result of excessive glycation and oxidation processes of proteins in hyperglycemia and oxidative stress conditions respectively, both in vivo and in vitro. In vivo these processes are especially intensified in patients with diabetes, and the adverse effects of AGE and AOPP are particularly unfavorable for the pathogenesis and aggravate the biochemical disturbances and clinical complications of diabetes. Total AGE and AOPP (T-AGE and T-AOPP) are heterogeneous groups of compounds, and they can be divided into two main fractions: high- and low-molecular-weight, i.e. HMW-AGE and HMW-AOPP as well as LMW-AGE and LMW-AOPP. Therefore it is important to find natural substances that will prevent formation of total AGE and AOPP and their high- and low-molecular-weight fractions and thereby reduce their adverse effects on tissues and organs.

Method

Selected natural substances and dietary supplements such as vitamin C, aminoguanidine, quercetin and green tea as well as the multicompound formulations Padma Circosan and Padma 28 were tested in an in vitro model using bovine serum albumin (BSA). Fluorescence of T-, HMW- and LMW-AGE and concentration of T-, HMW- and LMW-AOPP were measured after incubation with these substances.

Results

In the examined concentrations quercetin showed the greatest degree of inhibition for T-AGE (60.5 %) as well as for HMW-AGE (79.5 %), while in the case of LMW-AGE the greatest degree of glycation inhibition was shown by Padma Circosan (74.9 %). T-AOPP and HMW-AOPP were best inhibited by vitamin C (87.3 and 89.1 % respectively). The results obtained for LMW-AOPP are atypical, but the lowest concentration was observed in a sample with Padma 28.

Conclusion

The results show that all tested natural compounds have inhibitory activity towards the formation of total and low- and high-molecular-weight forms of AGE and AOPP in vitro. That suggest a possible role in the prevention of diabetic complications, especially the multiherbal compound Padma preparations, which are especially effective in lowering the most dangerous, i.e. LMW fractions.