Daidzein suppresses pro-inflammatory chemokine Cxcl2 transcription in TNF-α-stimulated murine lung epithelial cells via depressing PARP-1 activity

Unlocking daidzein's healing power: Present applications and future possibilities in phytomedicine

BACKGROUND

Cancer is one of the leading causes of death and a great threat to people around the world. Cancer treatment modalities include surgery, radiotherapy, chemotherapy, radiochemotherapy, hormone therapy, and immunotherapy. The best approach is to use a combination of several types. Among the treatment methods mentioned above, chemotherapy is frequently used, but its activity is hampered by the development of drug resistance and many side effects. In this regard, the use of medicinal plants has been discussed, and in recent decades, the use of isolated phytochemicals came into the focus of interest. By critically evaluating the available evidence and emphasizing the unique perspective offered by this review, we provide insights into the potential of daidzein as a promising therapeutic agent, as well as outline future research directions to optimize its efficacy in clinical settings.

PURPOSE

To summarized the therapeutic potential of daidzein, an isoflavone phytoestrogen in the management of several human diseases with the focuses on the current status and future prospects as a therapeutic agent.

METHODS

Several search engines, including PubMed, GoogleScholar, and ScienceDirect, were used, with the search terms "daidzein", "daidzein therapeutic potential", or individual effects. The study included all peer-reviewed articles. However, the most recent publications were given priority.

RESULTS

Daidzein showed protective effects against malignant diseases such as breast cancer, prostate cancer but also non-malignant diseases such as diabetes, osteoporosis, and cardiovascular diseases. Daidzein activates multiple signaling pathways leading to cell cycle arrest and apoptosis as well as antioxidant and anti-metastatic effects in malignant cells. Moreover, the anticancer effects against different cancer cells were more prominent and discussed in detail.

CONCLUSIONS

In short, daidzein represents a promising compound for drug development. The comprehensive potential anticancer activities of daidzein through various molecular mechanisms and its therapeutic/clinical status required further detail studies.

Interpretation of the anti-influenza active ingredients and potential mechanisms of Ge Gen Decoction based on spectrum-effect relationships and network analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Ge Gen Decoction (GGD) is a classic traditional Chinese medicine (TCM) prescription that originated in the ancient Chinese medical book "Treatise on Febrile Diseases". The prescription consists of 7 herbs: Pueraria lobata (Willd.) Ohwi, Ephedra sinica Stapf, Cinnamomum cassia (L.) J.Presl, Paeonia lactiflora Pall., Glycyrrhiza uralensis Fisch., Zingiber officinale Rosc., and Ziziphus jujuba Mill. It can alleviate high fever and soreness in the neck and shoulders caused by exogenous wind chill and is widely used in both China and Japan. Currently, GGD is primarily utilized for treating flu and the common cold. GGD has been reported to show significant anti-influenza A virus (IAV) activity both in vitro and in vivo. However, the active ingredients responsible for its anti-influenza properties have not been elucidated, and the mechanisms underlying its anti-influenza effects require further research.

AIM OF THE STUDY

This study aims to investigate the active ingredients and molecular mechanisms of GGD in treating influenza.

MATERIALS AND METHODS

HPLC chromatograms were established for GGD water and different polar extracts. The effect of different GGD extracts on pulmonary virus titers and TNFα expression was assessed through RT-PCR analysis. Spectrum-effect relationships between chromatographic peaks of GGD and its virus inhibition rate and TNFα inhibition rate were investigated using partial least squares regression (PLSR) analysis. HPLC-Q-TOF-MS was utilized to identify the constituents absorbed into the blood after oral administration of GGD. Network analysis of the absorbed forms of active ingredients was conducted to predict the potential mechanisms of GGD. Subsequently, total SOD activity, CAT and HO-1 expression and Nrf2 nuclear translocation were then analyzed. Finally, the impact of interfering with HO-1 expression on the anti-IAV activity of GGD was examined.

RESULTS

The study identified 11 anti-influenza active ingredients in GGD, which are daidzein, ononin, genistin, daidzin, 3'-methoxypuerarin, puerarin, pseudoephedrine, paeoniflorin, pormononetin-7-xylosyl-glucoside, penistein-7-O-apiosyl-glucoside, and ephedrine. Network analysis revealed various biological activities of GGD, including responses to ROS and oxidative stress. GGD also involves multiple antiviral pathways, such as hepatitis B, IAV, and Toll-like receptor pathways. Experimental assays demonstrated that GGD possesses independent antioxidant activity both in vitro and in vivo. In vitro, GGD inhibits the increase in intracellular ROS induced by IAV. In vivo, it reduces MDA levels and increases total pulmonary SOD activity. Applying siRNA and flow cytometry analysis revealed that GGD alleviates IAV-induced oxidative burst by promoting the expression of HO-1 and CAT. Western blot analysis revealed that GGD effectively promotes Nrf2 nuclear translocation and enhances Nrf2 expression. Furthermore, this study found that the enhancement of HO-1 expression by GGD contributed to its anti-IAV activity.

CONCLUSIONS

The study identified the active ingredients of GGD against influenza and demonstrated the beneficial role of GGD's antioxidant activity in treating flu. The antioxidant activity of GGD is associated with the promotion of Nrf2 nuclear translocation and the upregulation of antioxidant enzymes such as SOD, HO-1, and CAT. Overall, this study provides evidence supporting the use of GGD as an adjunctive or complementary therapy for influenza.

Daidzein from Dietary Supplement to a Drug Candidate: An Evaluation of Potential

Daidzein (DDZ) is a well-known nutraceutical supplement belonging to the class of isoflavones. It is isolated from various sources such as alfalfa, soybean, and red clover. It demonstrates a broad array of pharmacological/beneficial properties such as cardiovascular exercise, cholesterol reduction, and anticancer, antifibrotic, and antidiabetic effects, which make it effective in treating a wide range of diseases. Its structure and operation are the same as those of human estrogens, which are important in preventing osteoporosis, cancer, and postmenopausal diseases. It is thus a promising candidate for development as a phytopharmaceutical. Addressing safety, efficacy, and physicochemical properties are the primary prerequisites. DDZ is already ingested every day in varying amounts, so there should not be a significant safety risk; however, each indication requires a different dose to be determined. Some clinical trials are already being conducted globally to confirm its safety, efficacy, and therapeutic potential. Furthermore, as a result of its therapeutic influence on health, in order to establish intellectual property, patents are utilized. In light of the vast potential of eugenol, this review presents a detailed data collection on DDZ to substantiate the claim to develop it in the therapeutic category.

Review on Additives in Hydrogels for 3D Bioprinting of Regenerative Medicine: From Mechanism to Methodology

The regeneration of biological tissues in medicine is challenging, and 3D bioprinting offers an innovative way to create functional multicellular tissues. One common way in bioprinting is bioink, which is one type of the cell-loaded hydrogel. For clinical application, however, the bioprinting still suffers from satisfactory performance, e.g., in vascularization, effective antibacterial, immunomodulation, and regulation of collagen deposition. Many studies incorporated different bioactive materials into the 3D-printed scaffolds to optimize the bioprinting. Here, we reviewed a variety of additives added to the 3D bioprinting hydrogel. The underlying mechanisms and methodology for biological regeneration are important and will provide a useful basis for future research.

Network Pharmacology and Molecular Docking Analysis Reveal Insights into the Molecular Mechanism of Shengma-Gegen Decoction on Monkeypox

Background: A new viral outbreak caused by monkeypox has appeared after COVID-19. As of yet, no specific drug has been found for its treatment. Shengma-Gegen decoction (SMGGD), a pathogen-eliminating and detoxifying agent composed of four kinds of Chinese herbs, has been demonstrated to be effective against several viruses in China, suggesting that it may be effective in treating monkeypox, however, the precise role and mechanisms are still unknown. Methods: Network pharmacology was used to investigate the monkeypox-specific SMGGD targets. These targets were analyzed via String for protein-to-protein interaction (PPI), followed by identification of hub genes with Cytoscape software. Function enrichment analysis of the hub targets was performed. The interactions between hub targets and corresponding ligands were validated via molecular docking. Results: Through screening and analysis, a total of 94 active components and 8 hub targets were identified in the TCM-bioactive compound-hub gene network. Molecular docking results showed that the active components of SMGGD have strong binding affinity for their corresponding targets. According to functional analysis, these hub genes are mainly involved in the TNF, AGE-RAGE, IL-17, and MAPK pathways, which are linked to the host inflammatory response to infection and viral replication. Therefore, SMGGD might suppress the replication of monkeypox virus through the MAPK signaling pathway while also reducing inflammatory damage caused by viral infection. Conclusion: SMGGD may have positive therapeutic effects on monkeypox by reducing inflammatory damage and limiting virus replication.

Caenorhabditis elegans as a Model for the Effects of Phytochemicals on Mitochondria and Aging

The study of aging is an important topic in contemporary research. Considering the demographic changes and the resulting shifts towards an older population, it is of great interest to preserve youthful physiology in old age. For this endeavor, it is necessary to choose an appropriate model. One such model is the nematode Caenorhabditis elegans (C. elegans), which has a long tradition in aging research. In this review article, we explore the advantages of using the nematode model in aging research, focusing on bioenergetics and the study of secondary plant metabolites that have interesting implications during this process. In the first section, we review the situation of aging research today. Conventional theories and hypotheses about the ongoing aging process will be presented and briefly explained. The second section focuses on the nematode C. elegans and its utility in aging and nutrition research. Two useful genome editing methods for monitoring genetic interactions (RNAi and CRISPR/Cas9) are presented. Due to the mitochondria's influence on aging, we also introduce the possibility of observing bioenergetics and respiratory phenomena in C. elegans. We then report on mitochondrial conservation between vertebrates and invertebrates. Here, we explain why the nematode is a suitable model for the study of mitochondrial aging. In the fourth section, we focus on phytochemicals and their applications in contemporary nutritional science, with an emphasis on aging research. As an emerging field of science, we conclude this review in the fifth section with several studies focusing on mitochondrial research and the effects of phytochemicals such as polyphenols. In summary, the nematode C. elegans is a suitable model for aging research that incorporates the mitochondrial theory of aging. Its living conditions in the laboratory are optimal for feeding studies, thus enabling bioenergetics to be observed during the aging process.

Isoflavones daidzin and daidzein inhibit lipopolysaccharide-induced inflammation in RAW264.7 macrophages

Background

Inflammation contributes to various diseases and soybeans and legumes are shown to reduce inflammation. However, the bioactive ingredients involved and mechanisms are not completely known. We hypothesized that soy isoflavones daidzin and daidzein exhibit anti-inflammatory effect in lipopolysaccharides (LPS)-stimulated RAW264.7 macrophage cell model and that activation mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways may mediate the effect.

Methods

Cell viability and nitric oxide (NO) level were determined by 3-(4,5)-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Griess reagent respectively. ELISA kits and Western blotting respectively assessed the generations of pro-inflammatory cytokines and protein expressions of signaling molecules. p65 nuclear translocation was determined by immunofluorescence assay.

Results

The in vitro results showed that both isoflavones did not affect cell viability at the concentrations being tested and significantly reduced levels of NO, pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor-α (TNF-α), and inflammatory indicators such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in RAW264.7 cells. Daidzin and daidzein partially suppressed MAPK signaling pathways, reducing the phosphorylation of p38 and ERK; whilst phosphorylation of JNK was mildly but not significantly decreased. For the involvement of NF-κB signaling pathways, daidzin only reduced the phosphorylation of p65 whereas daidzein effectively inhibited the phosphorylation of IKKα/β, IκBα and p65. Daidzin and daidzein inhibited p65 nuclear translocation, comparable with dexamethasone (positive control).

Conclusion

This study supports the anti-inflammatory effects of isoflavones daidzin and daidzein, which were at least partially mediated through inactivation of MAPK and/or NF-κB signaling pathways in macrophages.

Investigation on the influence factors for the fracturing effect in fractured tight reservoirs using the numerical simulation

Taking the fractured tight reservoir of the Fengcheng Formation in Mahu Depression as the research object, the RFPA software, a numerical simulation platform of real fracture process, was used to study the fracture propagation laws in fractured tight reservoirs during the fracturing process. On this basis, the influences of different factors on the fracture propagation laws in the fractured tight reservoirs were investigated, the influences of various factors on fracture propagation were quantitatively analyzed by the gray correlation method, and then the fractability calculation model for evaluating the fracturing effects was obtained by the analytic hierarchy process method. The results show that when the fracture angle is less than 70°, the natural fracture controls the hydraulic fracture propagation direction, whereas when the fracture angle is greater than 70°, the maximum horizontal principal stress controls the hydraulic fracture propagation direction. With the increase of the fracture angle, the hydraulic fracturing area firstly decreases and then increases, whereas with the increase of the fracture density, the hydraulic fracturing area gradually increases. The hydraulic fracturing area increases as the fracture compressive strength, tensile strength and elastic modulus reduction factor increase, whereas the hydraulic fracturing area decreases as the fracture Poisson's ratio reduction factor increases. Based on the gray correlation method, the ranking of the fracturing effect is clarified as fracture density > horizontal stress difference > fracture angle > elastic modulus > compressive strength > tensile strength > Poisson's ratio. Using the analytic hierarchy process, a model for calculating the reservoir fractability index is established, and has a good positive correlation with the dimensionless fracturing area.

CXCL2 Impairs Functions of Bone Marrow Mesenchymal Stem Cells and Can Serve as a Serum Marker in High-Fat Diet-Fed Rats

In modern society excessive consumption of a high-fat diet (HFD) is a significant risk factor for many diseases such as diabetes, osteoarthritis and certain cancers. Resolving cellular and molecular mechanisms underlying HFD-associated disorders is of great importance to human health. Mesenchymal stem cells (MSCs) are key players in tissue homeostasis and adversely affected by prolonged HFD feeding. Low-grade systemic inflammation induced by HFD is characterized by increased levels of pro-inflammatory cytokines and alters homeostasis in many organs. However, whether, which and how HFD associated inflammatory cytokines impair MSCs remain unclear. Here we demonstrated that HFD induced serum cytokines disturbances, especially a continuous elevation of serum CXCL2 level in rats. Coincidentally, the differentially expressed genes (DEGs) of bone marrow MSCs (BMSCs) which functions were impaired in HFD rats were enriched in cytokine signaling. Further mechanism analysis revealed that CXCL2 treatment in vitro suppresses the adipogenic potential of BMSCs via Rac1 activation, and promoted BMSC migration and senescence by inducing over-production of ELMO1 and reactive oxygen species (ROS) respectively. Moreover, we found that although glycolipid metabolism indicators can be corrected, the CXCL2 elevation and BMSC dysfunctions cannot be fully rescued by diet correction and anti-inflammatory aspirin treatment, indicating the long-lasting deleterious effects of HFD on serum CXCL2 levels and BMSC functions. Altogether, our findings identify CXCL2 as an important regulator in BMSCs functions and may serve as a serum marker to indicate the BMSC dysfunctions induced by HFD. In addition, our findings underscore the intricate link among high-fat intake, chronic inflammation and BMSC dysfunction which may facilitate development of protective strategies for HFD associated diseases.

Controlled release of soy isoflavones from multifunctional 3D printed bone tissue engineering scaffolds

Recent challenges in post-surgical bone tumor management have elucidated the need for a multifunctional scaffold, which can be used for residual tumor-cell suppression, defect repair, and simultaneous bone regeneration. In this perspective, 3D printing allows to create a wide variety of patient-specific implant with complex porous architecture and compatible mechanical strength to that of cancellous bone. Here, a multifunctional bone graft substitute is designed by incorporating the three primary soy isoflavones: genistein, daidzein, and glycitein onto a 3D printed (3DP) tricalcium phosphate (TCP) scaffolds with designed pores, endowing them with in vitro chemopreventive, bone-cell proliferating and immune-modulatory potential. The interconnected porosity and biodegradability of 3DP TCP ceramics have allowed controlled release kinetics of genistein, daidzein and glycitein in acidic and physiological buffer medium for 16 days, which is fitted with Korsmeyer-Peppas model. Presence of genistein, a well-known natural biomolecule shows a 90% reduction in vitro osteosarcoma (MG-63) cell viability and proliferation after 11 days. Meanwhile, daidzein, the other primary isoflavone, promotes in vitro cellular attachment and enhances viability and proliferation of human fetal osteoblast cell (hFOB). Furthermore, controlled release of genistein, daidzein, and glycitein from 3DP TCP scaffold demonstrates improved hFOB cell proliferation, viability, and differentiation in a dynamic flow-perfusion bioreactor, which is utilized to better simulate the clinical microenvironment. Finally, in vivo H&E staining confirms controlled co-delivery of genistein-daidzein-glycitein from 3DP scaffold carefully modulated neutrophil recruitment to the surgery site after 24 h of implantation in a rat distal femur model. These results advance our understanding towards multipronged therapeutic approaches utilizing synthetic bone graft substitutes as a drug delivery vehicle, and more importantly, demonstrate the feasibility of localized tumor cell suppression and bone cell proliferation for post-surgical defect repair application. STATEMENT OF SIGNIFICANCE: Designed multimodal porosity of 3D printed TCP scaffold allows a controlled and sustained release of soy isoflavones, genistein, daidzein and glycitein in both physiological and acidic pH. Presence of genistein shows 90% reduction in vitro bone cancer cell viability and proliferation. Meanwhile, controlled release of genistein, daidzein, and glycitein from 3DP TCP scaffolds demonstrate improved osteoblast cell proliferation, viability, and differentiation in static and dynamic flow-perfusion bioreactor. Furthermore, H&E staining at 24 h post-surgical specimens from rat distal femur model shows neutrophil recruitment at the surgery site is significantly decreased, suggesting the anti-inflammatory property of soy isoflavones. This work provides deeper understanding on the design of a multifunctional 3D printed patient-specific scaffold with enhanced in vitro chemopreventive, osteogenic and in vivo anti-inflammatory ability.

The effect of soya consumption on inflammatory biomarkers: a systematic review and meta-analysis of clinical trials

Inflammation is a major cause of chronic diseases. Several studies have investigated the effects of soya intake on inflammatory biomarkers; however, the results are equivocal. The aim of this study was to conduct a systematic review and meta-analysis of clinical trials that evaluated the effect of soya consumption on inflammatory biomarkers. Medline, Scopus, ISI Web of Science and Google Scholar were systematically searched, up to and including May 2020, for clinical trials that evaluated the effects of soya and soya products on TNF-α, IL-6, IL-2, IL-1β and interferon γ (IFN-γ) in adults. A random effects method was used to calculate overall effects, and subgroup analyses were performed to discern probable sources of inter-study heterogeneity. A total of twenty-eight clinical trials were included. Although soya consumption reduced TNF-α (Hedges' g = -0·28; 95 % CI -0·49, -0·07), it had no significant effect on IL-6 (Hedges' g = 0·07, 95 % CI -0·14, 0·28), IL-2 (mean difference (MD) = -1·38 pg/ml; 95 % CI -3·07, 0·31), IL-1β (MD = -0·02 pg/ml; 95 % CI -0·08, 0·03) and IFN-γ (MD = 1685·82 pg/ml; 95 % CI -1604·86, 4976·50). Subgroup analysis illustrated a reduction in TNF-α in parallel designed studies, at dosages ≥100 mg of isoflavones, and in unhealthy subjects. The present study showed that high doses of isoflavones in unhealthy subjects may yield beneficial effects on TNF-α.

c-Abl-Mediated Tyrosine Phosphorylation of PARP1 Is Crucial for Expression of Proinflammatory Genes

Poly(ADP-ribosyl)ation is a rapid and transient posttranslational protein modification mostly catalyzed by poly(ADP-ribose) polymerase-1 (PARP1). Fundamental roles of activated PARP1 in DNA damage repair and cellular response pathways are well established; however, the precise mechanisms by which PARP1 is activated independent of DNA damage, and thereby playing a role in expression of inflammatory genes, remain poorly understood. In this study, we show that, in response to LPS or TNF-α exposure, the nonreceptor tyrosine kinase c-Abl undergoes nuclear translocation and interacts with and phosphorylates PARP1 at the conserved Y829 site. Tyrosine-phosphorylated PARP1 is required for protein poly(ADP-ribosyl)ation of RelA/p65 and NF-κB-dependent expression of proinflammatory genes in murine RAW 264.7 macrophages, human monocytic THP1 cells, or mouse lungs. Furthermore, LPS-induced airway lung inflammation was reduced by inhibition of c-Abl activity. The present study elucidated a novel signaling pathway to activate PARP1 and regulate gene expression, suggesting that blocking the interaction of c-Abl with PARP1 or pharmaceutical inhibition of c-Abl may improve the outcomes of PARP1 activation-mediated inflammatory diseases.

The Role of PARPs in Inflammation-and Metabolic-Related Diseases: Molecular Mechanisms and Beyond

Poly(ADP-ribosyl)ation (PARylation) is an essential post-translational modification catalyzed by poly(ADP-ribose) polymerase (PARP) enzymes. Poly(ADP-ribose) polymerase 1 (PARP1) is a well-characterized member of the PARP family. PARP1 plays a crucial role in multiple biological processes and PARP1 activation contributes to the development of various inflammatory and malignant disorders, including lung inflammatory disorders, cardiovascular disease, ovarian cancer, breast cancer, and diabetes. In this review, we will focus on the role and molecular mechanisms of PARPs enzymes in inflammation- and metabolic-related diseases. Specifically, we discuss the molecular mechanisms and signaling pathways that PARP1 is associated with in the regulation of pathogenesis. Recently, increasing evidence suggests that PARP inhibition is a promising strategy for intervention of some diseases. Thus, our in-depth understanding of the mechanism of how PARPs are activated and how their signaling downstream effecters can provide more potential therapeutic targets for the treatment of the related diseases in the future is crucial.

Isoflavone Aglycones Attenuate Cigarette Smoke-Induced Emphysema via Suppression of Neutrophilic Inflammation in a COPD Murine Model

Chronic obstructive pulmonary disease (COPD), a lung disease caused by chronic exposure to cigarette smoke, increases the number of inflammatory cells such as macrophages and neutrophils and emphysema. Isoflavone is a polyphenolic compound that exists in soybeans. Daidzein and genistein, two types of isoflavones, have been reported to have anti-inflammatory effects in various organs. We hypothesized that the daidzein-rich soy isoflavone aglycones (DRIAs) attenuate cigarette smoke-induced emphysema in mice. Mice were divided into four groups: the (i) control group, (ii) isoflavone group, (iii) smoking group, and (iv) isoflavone + smoking group. The number of inflammatory cells in the bronchoalveolar lavage fluid (BALF) and the airspace enlargement using the mean linear intercept (MLI) were determined 12 weeks after smoking exposure. Expressions of neutrophilic inflammatory cytokines and chemokines were also examined. In the isoflavone + smoking group, the number of neutrophils in BALF and MLI was significantly less than that in the smoking group. Furthermore, the gene-expressions of TNF-α and CXCL2 (MIP-2) in the isoflavone + smoking group were significantly less than those in the smoking group. Supplementation of the COPD murine model with DRIAs significantly attenuates pathological changes of COPD via suppression of neutrophilic inflammation.

7,8,4'-Trihydroxyisoflavone, a Metabolized Product of Daidzein, Attenuates 6-Hydroxydopamine-Induced Neurotoxicity in SH-SY5Y Cells

Daidzein isolated from soybean (Glycine max) has been widely studied for its antioxidant and anti-inflammatory activities. However, the protective effects of 7,8,4'-trihydroxyisoflavone (THIF), a major metabolite of daidzein, on 6-hydroxydopamine (OHDA)-induced neurotoxicity are not well understood. In the current study, 7,8,4'-THIF significantly inhibited neuronal cell death and lactate dehydrogenase (LDH) release induced by 6-OHDA in SH-SY5Y cells, which were used as an in vitro model of Parkinson' disease (PD). Moreover, pretreatment with 7,8,4'-THIF significantly increased the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) and decreased malondialdehyde (MDA) activity in 6-OHDA-induced SH-SY5Y cells. In addition, 7,8,4'-THIF significantly recovered 6-OHDA-induced cleaved caspase-3, cleaved caspase-9, cleaved poly-ADP-ribose polymerase (PARP), increased Bax, and decreased Bcl-2 levels. Additionally, 7,8,4'-THIF significantly restored the expression levels of phosphorylated c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase 1/2 (ERK 1/2), phosphatidylinositol 3-kinases (PI3K)/Akt, and glycogen synthase kinase-3 beta (GSK-3β) in 6-OHDA-induced SH-SY5Y cells. Further, 7,8,4'-THIF significantly increased the reduced tyrosine hydroxylase (TH) level induced by 6-OHDA in SH-SY5Y cells. Collectively, these results suggest that 7,8,4'-THIF protects against 6-OHDA-induced neuronal cell death in cellular PD models. Also, these effects are mediated partly by inhibiting activation of the MAPK and PI3K/Akt/GSK-3β pathways.

Protective effect of daidzein against streptozotocin-induced Alzheimer's disease via improving cognitive dysfunction and oxidative stress in rat model

Oxidative stress is performing an essential role in developing Alzheimer's disease (AD), and age-related disorder and other neurodegenerative diseases. In existing research, we have aimed at investigating the daidzein (4',7-dihydroxyisoflavone) effect (10 and 20 mg/kg of body weight), as a free radical scavenger and antioxidant in streptozotocin (STZ) infused AD in rat model. Daidzein treatment led to significant improvement in intracerebroventricular-streptozotocin (ICV-STZ)-induced memory and learning impairments that was evaluated by Morris water maze test and spontaneous locomotor activity. It significantly restored the alterations in malondialdehyde, catalase, superoxide dismutase, and reduced glutathione levels. In addition, histopathological observations in cerebral cortex and hippocampal areas confirmed the neuroprotective effect of daidzein. These outcomes provide experimental proof showing preventive effect of daidzein on memory, learning dysfunction and oxidative stress in case of ICV-STZ rats. In conclusion, daidzein offers a potential treatment module for various neurodegenerative disorders with regard to mental deficits like AD.

Daidzein, its effects on impaired glucose and lipid metabolism and vascular inflammation associated with type 2 diabetes

Over the last decades, the incidence of type 2 diabetes (T2D) is increasing substantially. Emerging evidences from epidemiological studies have shown the association between higher intake of soy isoflavones and reduced risk of T2D and its associated health risks. Daidzein, a soy isoflavone, has been found to have a promising therapeutic potential in managing T2D pathophysiology. Fermented soybean is the major source of daidzein; however, it can also be formed via the consumption of its glycosylated moiety, daidzin with subsequent hydrolysis by intestinal bacterial enzyme. Many studies reported the prophylactic effect of daidzein on the improvement of hyperglycemia, insulin resistance, dislipidemia, obesity, inflammation, and other complications associated with T2D. The molecular mechanisms underlying the action of daidzein include diverged pathways where daidzein has been shown to interact with several signaling molecules and receptors to achieve desirable effect. Although the specific molecular mechanism is still elusive, further studies are thus needed to understand it in detail. In this review, we discuss the antidiabetic potential of daidzein with respect to the evidences from various clinical, preclinical, and cell culture studies and the underlying molecular mechanism in a precise way to have a comprehensive account on this isoflavone with promising therapeutic potential. © 2018 BioFactors, 44(5):407-417, 2018.

Suppression of Proinflammatory Cytokines and Mediators in LPS-Induced RAW 264.7 Macrophages by Stem Extract of Alternanthera sessilis via the Inhibition of the NF-κB Pathway

Alternanthera sessilis, an edible succulent herb, has been widely used as herbal drug in many regions around the globe. Inflammation is a natural process of the innate immune system, accompanied with the increase in the level of proinflammatory mediators, for example, nitric oxide (NO) and prostaglandin (PGE2); cytokines such as interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor alpha (TNFα); and enzymes including inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) via the activation and nuclear translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) subunit p65 due to the phosphorylation of inhibitory protein, IκBα. Inflammation over a short period of time is essential for its therapeutic effect. However, prolonged inflammation can be detrimental as it is related to many chronic diseases such as delayed wound healing, cardiovascular disease, arthritis, and autoimmune disorders. Therefore, ways to curb chronic inflammation have been extensively investigated. In line with that, in this present study, we attempted to study the suppression activity of the proinflammatory cytokines and mediators as a characteristic of anti-inflammatory action, by using stem extract of A. sessilis in the lipopolysaccharide- (LPS-) stimulated RAW 264.7 macrophage cell line. The results showed that the extract has significantly inhibited the production of the proinflammatory mediators including NO and PGE2; cytokines comprising IL-6, IL-1β, and TNFα; and enzymes covering the iNOS and COX-2 by preventing the IκBα from being degraded, to inhibit the nuclear translocation of NF-κB subunit p65 in order to hinder the inflammatory pathway activation. These results indicated that the stem extract of A. sessilis could be an effective candidate for ameliorating inflammatory-associated complications.

Targeting NAD+ degradation: The therapeutic potential of flavonoids for Alzheimer's disease and cognitive frailty

Flavonoids are efficacious candidates as pharmaceuticals or nutraceuticals in the treatment of Alzheimer's disease (AD), aging and other age-related chronic inflammatory diseases. Natural flavonoids reduce pathological hallmarks, extracellular amyloid deposits and neurofibrillary tangles by mediating amyloid precursor protein (APP) processing, Aβ accumulation and tau pathology. The antioxidant and anti-inflammatory actions as well as modulation of sirtuins and telomeres are also involved in the amelioration of aging, neurodegeneration and other age-related diseases. Recently, some flavonoids were shown to inhibit poly (ADP-ribose) polymerases (PARPs) and cyclic ADP-ribose (cADP) synthases (CD38 and CD157), elevate intracellular nicotinamide adenine dinucleotide⁺ (NAD⁺) levels and activate NAD⁺ dependent sirtuin -mediated signaling pathways. We summarized how flavonoids reduce the degradation of NAD⁺ with an emphasis on the mechanisms through which flavonoids affect the NAD⁺-sirtuin axis to protect against AD. Aging and age-related diseases as well as a decline in the physiological reserve are the risk factors for cognitive frailty. Flavonoids with multiple therapeutic targets may also be potential candidates for the prevention and treatment of cognitive frailty.

PARP1 promotes gene expression at the post-transcriptiona level by modulating the RNA-binding protein HuR

Poly(ADP-ribosyl)ation (PARylation) is mainly catalysed by poly-ADP-ribose polymerase 1 (PARP1), whose role in gene transcription modulation has been well established. Here we show that, in response to LPS exposure, PARP1 interacts with the adenylateuridylate-rich element-binding protein embryonic lethal abnormal vision-like 1 (Elavl1)/human antigen R (HuR), resulting in its PARylation, primarily at site D226. PARP inhibition and the D226 mutation impair HuR's PARylation, nucleocytoplasmic shuttling and mRNA binding. Increases in mRNA level or stability of pro-inflammatory cytokines/chemokines are abolished by PARP1 ablation or inhibition, or blocked in D226A HuR-expressing cells. The present study demonstrates a mechanism to regulate gene expression at the post-transcriptional level, and suggests that blocking the interaction of PARP1 with HuR could be a strategy to treat inflammation-related diseases that involve increased mRNA stability.

PARP1, in addition to its role in DNA repair, has a role in regulating gene transcription via PARylation of target proteins. Here the authors show that HuR is targeted after lipopolysaccharide exposure to regulate the inflammatory gene expression at post-transcriptional level.

Isoflavones: Anti-Inflammatory Benefit and Possible Caveats

Inflammation, a biological response of body tissues to harmful stimuli, is also known to be involved in a host of diseases, such as obesity, atherosclerosis, rheumatoid arthritis, and even cancer. Isoflavones are a class of flavonoids that exhibit antioxidant, anticancer, antimicrobial, and anti-inflammatory properties. Increasing evidence has highlighted the potential for isoflavones to prevent the chronic diseases in which inflammation plays a key role, though the underlying mechanisms remain unclear. Recently, some studies have raised concerns about isoflavones induced negative effects like carcinogenesis, thymic involution, and immunosuppression. Therefore, this review aims to summarize the anti-inflammatory effects of isoflavones, unravel the underlying mechanisms, and present the potential health risks.