Isoflavone genistein and daidzein up-regulate LPS-induced inducible nitric oxide synthase activity through estrogen receptor pathway in RAW264.7 cells

Potential therapeutic interventions of plant-derived isoflavones against acute lung injury

Acute lung injury (ALI) is a life-threatening syndrome that possibly leads to high morbidity and mortality as no therapy exists. Several natural ingredients with negligible adverse effects have recently been investigated to possibly inhibit the inflammatory pathways associated with ALI at the molecular level. Isoflavones, as phytoestrogenic compounds, are naturally occurring bioactive compounds that represent the most abundant category of plant polyphenols (Leguminosae family). A broad range of therapeutic activities of isoflavones, including antioxidants, chemopreventive, anti-inflammatory, antiallergic and antibacterial potentials, have been extensively documented in the literature. Our review exclusively focuses on the possible anti-inflammatory, antioxidant role of botanicals'-derived isoflavones against ALI and their immunomodulatory effect in experimentally induced ALI. Despite the limited scope covering their molecular mechanisms, isoflavones substantially contributed to protecting from ALI via inhibiting toll-like receptor 4 (TLR4)/Myd88/NF-κB pathway and subsequent cytokines, chemokines, and adherent proteins. Nonetheless, future research is suggested to fill the gap in elucidating the protective roles of isoflavones to alleviate ALI concerning antioxidant potentials, inhibition of the inflammatory pathways, and associated molecular mechanisms.

Prunetin inhibits nitric oxide activity and induces apoptosis in urinary bladder cancer cells via CASP3 and TNF-α genes

BACKGROUND

Urinary bladder cancer (UBC) is considered one of the most prevalent malignant tumors worldwide. Complementary and integrative approaches for the treatment of bladder cancer, such as the intake of isoflavonoid phytoestrogens, are of increasing interest due to the risk of mortality and long-term morbidity associated with surgical procedures. The biological effects of prunetin, one of the less-studied phytoestrogens, have not yet been examined in this respect. Therefore, this study aimed to explore the efficacy of prunetin on UBC cells (RT-4). METHODS AND RESULTS: The cytotoxicity and nitric oxide synthase activities of prunetin were determined in cell cultures. The expression of apoptosis-related genes was determined with RT-PCR. Cell cycle assays were performed using a flow cytometer and cellular apoptotic rate was measured. The results suggested that prunetin has cytotoxic effects at 21.11 µg/mL on RT-4 cells. Flow cytometry analysis showed that prunetin induced apoptosis and arrested th cell cycle in the G₀/G₁ phase. Prunetin exposure was associated with increases in CASP3 and TNF-α gene expression in RT-4 cells at doses of 21.11 and 42.22 µg/mL, respectively. Strong nitric oxide inhibition was observed at IC₅₀ of 5.18 µg/mL under macrophage mediated inflammatory circumstances.

CONCLUSIONS

Prunetin possesses anti-cancer properties and may be a candidate compound for the prevention of UBC. This is the first study that evaluated prunetin for its in vitro antitumor activities, clarified its possible apoptotic molecular mechanism and provided novel insights into its anti-inflammatory nature and effects on the expression of related key genes.

Experimental and clinical studies on the effects of Portulaca oleracea L. and its constituents on respiratory, allergic, and immunologic disorders, a review

Various pharmacological effects for Portulaca oleracea were shown in previous studies. Therefore, the effects of P. oleracea and its derivatives on respiratory, allergic, and immunologic diseases according to update experimental and clinical studies are provided in this review article. PubMed/Medline, Scopus, and Google Scholar were searched using appropriate keywords until the end of December 2020. The effects of P. oleracea and its constituents such as quercetin and kaempferol on an animal model of asthma were shown. Portulaca oleracea and its constituents also showed therapeutic effects on chronic obstructive pulmonary disease and chronic bronchitis in both experimental and clinical studies. The possible bronchodilatory effect of P. oleracea and its ingredients was also reported. Portulaca oleracea and its constituents showed the preventive effect on lung cancer and a clinical study showed the effect of P. oleracea on patients with lung adenocarcinoma. In addition, a various constituents of P. oleracea including, quercetin and kaempferol showed therapeutic effects on lung infections. This review indicates the therapeutic effect of P. oleracea and its constituents on various lung and allergic disorders but more clinical studies are required to establish the clinical efficacy of this plant and its constituents on lung and allergic disorders.

Genistein reduces the activation of AKT and EGFR, and the production of IL6 in cholangiocarcinoma cells involving estrogen and estrogen receptors

Cholangiocarcinoma (CCA) is a malignant tumor of the biliary epithelium associated with Opisthorchis viverrini, primary sclerosing cholangitis and hepatitis viral infection. In the global population, men have higher incidence rates for CCA than women; thus, a gender disparity in the progression of chronic inflammation of the biliary duct leading to malignancy may involve the effects of estrogen (E2). Genistein (GE), a prominent phytoestrogen found in soy products, is an estrogen receptor β (ERβ) agonist and a tyrosine kinase inhibitor. The present study investigated the effects of GE on the growth of CCA cells by cell viability assay. The effects on signaling proteins were detected by western blot analysis and ELISA. Gene expression was examined by RT-qPCR. Two human intrahepatic CCA cell lines, HuCCA‑1 and RMCCA‑1, were utilized. GE (50‑200 µM) reduced the viability of the two cell lines, and also inhibited the activation of epidermal growth factor receptor (EGFR) and AKT, as evidenced by decreasing protein levels of phosphorylated (p)-EGFR (Tyr1173) and p‑AKT (Ser473), respectively. GE altered the mitogen‑activated protein kinase signaling cascade by mediating decreased protein levels of p‑p38 and increased protein levels of p‑ERK1/2. GE significantly decreased the levels of interleukin 6 (IL6) and induced the expression of inducible nitric oxide synthase (iNOS). GE also downregulated the expression of p‑ERα (Ser118) protein and ERα mRNA levels. Finally, GE induced the downregulation of the protein levels of ERβ. Of note, E2 deprivation potentiated the GE-induced reduction of p‑EGFR (Tyr1173) and total AKT proteins and production of IL6, and mediated the downregulation of GE-induced iNOS protein. In conclusion, GE inhibited the growth of human CCA cell lines by reducing the activation of EGFR and AKT, and by attenuating the production of IL6. E2 and ER were also involved in the growth-inhibitory effect of GE in CCA cells.

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.

Estrogenic endocrine disruptors: Molecular mechanisms of action

A comprehensive summary of more than 450 estrogenic chemicals including estrogenic endocrine disruptors is provided here to understand the complex and profound impact of estrogen action. First, estrogenic chemicals are categorized by structure as well as their applications, usage and effects. Second, estrogenic signaling is examined by the molecular mechanism based on the receptors, signaling pathways, crosstalk/bypassing and autocrine/paracrine/homeostatic networks involved in the signaling. Third, evaluation of estrogen action is discussed by focusing on the technologies and protocols of the assays for assessing estrogenicity. Understanding the molecular mechanisms of estrogen action is important to assess the action of endocrine disruptors and will be used for risk management based on pathway-based toxicity testing.

Effect of direct loading of phytoestrogens into the calcium phosphate scaffold on osteoporotic bone tissue regeneration

3D porous calcium deficient hydroxyapatite scaffolds with phytoestrogens were fabricated for osteoporotic bone tissue regeneration through a combination of 3D printing techniques and cement chemistry as a room temperature process.

Cross-talk interactions of exogenous nitric oxide and sucrose modulates phenylpropanoid metabolism in yellow lupine embryo axes infected with Fusarium oxysporum

The aim of the study was to examine cross-talk of exogenous nitric oxide (NO) and sucrose in the mechanisms of synthesis and accumulation of isoflavonoids in embryo axes of Lupinus luteus L. cv. Juno. It was verified whether the interaction of these molecules can modulate the defense response of axes to infection and development of the pathogenic fungus Fusarium oxysporum f. sp. lupini. Sucrose alone strongly stimulated a high level of genistein glucoside in axes pretreated with exogenous nitric oxide (SNP or GSNO) and non-pretreated axes. As a result of amplification of the signal coming from sucrose and GSNO, high isoflavonoids accumulation was observed (+Sn+GSNO). It needs to be stressed that infection in tissues pretreated with SNP/GSNO and cultured on the medium with sucrose (+Si+SNP/+Si+GSNO) very strongly enhances the accumulation of free isoflavone aglycones. In +Si+SNP axes phenylalanine ammonia-lyase activity was high up to 72h. As early as at 12h in +Si+SNP axes an increase was recorded in gene expression level of the specific isoflavonoid synthesis pathway. At 24h in +Si+SNP axes a very high total antioxidant capacity dependent on the pool of fast antioxidants was noted. Post-infection generation of semiquinone radicals was lower in axes with a high level of sucrose than with a deficit.

Effect of 7-difluoromethyl-5, 4'-dimethoxygenistein on aorta atherosclerosis in hyperlipidemia ApoE(-/-) mice induced by a cholesterol-rich diet

Purpose

7-Difluoromethyl–5, 4′-dimethoxygenistein (DFMG), prepared by the difluoromethylation and alkylation of Genistein, is an active new chemical entity. Its anti-atherosclerosis effect was found in a series of studies in vitro. In this article, we explored and evaluated the anti-atherosclerosis effect via its protection of endothelial function in ApoE^−/− mice that were fed a high-fat diet.

Methods

Five C57BL/6J mice were selected as a control group and were fed a 1% high-fat diet (control group, n = 5). Five ApoE^−/− mice that were fed a high-fat diet for 16 weeks were selected as the atherosclerosis model group (model group, n = 5). In the phase I study, 25 ApoE^−/− mice were provided a prophylactic treatment with different drugs at the beginning of the 16 week high-fat diet: 5 mg/gk genistein (genistein 1 group, n = 5), 5 mg/kg lovastatin (lovastatin1 group, n = 5), 2.5 mg/kg DFMG (DFMG L1 group, n = 5), 5 mg/kg DFMG (DFMG M1 group, n = 5), and 10 mg/kg DFMG (DFMG H1 group, n = 5). In the phase II study, 25 atherosclerosis model, ApoE^−/− mice were treated with different drugs and fed a high-fat diet for 16 weeks: 5 mg/gk genistein (genistein 2 group, n = 5), 5 mg/kg lovastatin (lovastatin 2 group, n = 5), 2.5 mg/kg DFMG (DFMG L2 group, n = 5), 5 mg/kg DFMG (DFMG M2 group, n = 5), and 10 mg/kg DFMG (DFMG H2 group, n = 5). The plasma levels of lipids, von Willebrand factor (vWF), and nitrite were compared between phases I and II. Endothelium-dependent relaxation (EDR), aortic lesion development, and quantification in thoracic aortas were measured during these two phase studies.

Results

Compared to the model group, the lipid and vWF plasma levels were significantly lower, the plasma nitrite levels were significantly higher, the fatty streaks of aortic lesions were significantly lower, and the endothelium dependent relaxation was significantly higher after both phase studies (P < 0.05). The DFMG supplementation led to significant plasma nitrite increment in all groups after both phase studies (P < 0.05). There were significantly decreased fatty streaks of aortic lesions in DFMG-prevented and DFMG-treated mice (P < 0.05). There was a significant increase in EDR in all prophylactic treatment groups and treatment groups (P < 0.05). We further demonstrated that the preventative effect was more obvious than the therapeutic effect.

Conclusion

Our results suggest that DFMG could work in prophylactic and therapeutic treatments for atherosclerosis development.

A herbal formula containing roots of Salvia miltiorrhiza (Danshen) and Pueraria lobata (Gegen) inhibits inflammatory mediators in LPS-stimulated RAW 264.7 macrophages through inhibition of nuclear factor κB (NFκB) pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The herbal formula DG, containing roots of Salvia miltiorrhiza (Danshen) and Pueraria lobata (Gegen), has long history in treating cardiovascular diseases. It has been shown to be able to reduce intima-media thickening in coronary patients in our previous clinical study. Since intima-media thickening is the hallmark of atherosclerotic disease, the etiology of which is inflammation of the arterial wall, the mechanism underlying the effect of DG may be related to its anti-inflammatory activities.

AIM OF STUDY

The present study aims to determine the anti-inflammatory activity of DG and elucidate its underlying mechanisms with regards to its molecular basis of action.

MATERIALS AND METHOD

The anti-inflammatory effect of DG was studied by using lipopolysaccharide (LPS)-stimulated activation of nuclear factor κB (NFκB) pathway and subsequent production of inflammatory mediators, including nitric oxide (NO), prostaglandin E(2) (PGE(2)), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and macrophage chemotactic protein-1 (MCP-1), in mouse RAW 264.7 macrophages.

RESULTS

The present study demonstrated that DG could suppress the production of NO and PGE(2) through the inhibition of iNOS and COX-2 genes. DG could also inhibit the production of IL-1β, IL-6 and MCP-1, but not TNF-α, through the inhibition of respective mRNA expressions. Further investigations showed the inhibitory effect of DG on activation of IKKα/β and degradation of IκBα, thus preventing nuclear translocation of NFκB. All these results suggested the inhibitory effects of DG on the production of inflammatory mediators through the inhibition of the NFκB pathway.

CONCLUSIONS

The inhibitory effects of DG on the production of inflammatory mediators by LPS-stimulated RAW 264.7 macrophages, are accomplished by inhibiting the nuclear translocation of NFκB through inactivating IKKα/β and preventing degradation of IκBα.

Anti-inflammatory effects and the underlying mechanisms of action of daidzein in murine macrophages stimulated with Prevotella intermedia lipopolysaccharide

BACKGROUND AND OBJECTIVE

Host modulatory agents directed at inhibiting specific proinflammatory mediators could be beneficial in terms of attenuating periodontal disease progression and potentially enhancing therapeutic responses. The aim of this study was to investigate whether daidzein could modulate the production inflammatory mediators in macrophages stimulated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen implicated in periodontal disease, and to delineate underlying mechanisms of action.

MATERIAL AND METHODS

LPS was extracted from P. intermedia ATCC 25611 cells by the standard hot phenol-water method. The amounts of nitric oxide (NO) and interleukin-6 (IL-6) secreted into the culture medium were assayed. A real-time PCR was performed to quantify inducible nitric oxide synthase (iNOS) and IL-6 mRNA expression. We used immunoblot analysis to characterize iNOS protein expression, phosphrylation of c-Jun N-terminal kinase (JNK) and p38, degradation of inhibitory κB-α (IκB-α), nuclear translocation of nuclear factor-κB (NF-κB) subunits and phosphorylation of signal transducer and activator of transcription 1 (STAT1). The DNA-binding activity of NF-κB was assessed by using ELISA-based kits.

RESULTS

Daidzein significantly inhibited the production of NO and IL-6, as well as their mRNA expression, in P. intermedia LPS-treated RAW264.7 cells. The JNK and p38 pathways were not involved in the regulation of LPS-induced NO and IL-6 release by daidzein. Daidzein inhibited the degradation of IκB-α induced by P. intermedia LPS. In addition, daidzein suppressed NF-κB transcriptional activity via regulation of the nuclear translocation and DNA-binding activity of NF-κB p50 subunit and blocked STAT1 phosphorylation.

CONCLUSION

Although additional studies are required to dissect the molecular mechanism of action, our results suggest that daidzein could be a promising agent for treating inflammatory periodontal disease. Further research in animal models of periodontitis is necessary to better evaluate the potential of daidzein as a novel therapeutic agent to treat periodontal disease.

Alcohol-fermented soybean increases the expression of receptor-interacting protein 2 and IκB kinase β in mouse peritoneal macrophages

Soybean is a useful component of traditional Korean medicine with well-documented health-promoting effects. We investigated the effects of alcohol-fermented soybean (AFS) on immune function. When AFS treatment was used in combination with recombinant interferon-γ (rIFN-γ), there was a marked cooperative induction of nitric oxide (NO) and tumor necrosis factor (TNF)-α production in mouse peritoneal macrophages. AFS increased the expression of inducible NO synthase mRNA and protein in rIFN-γ-primed macrophages. Treating macrophages with pyrrolidine dithiocarbamate, an inhibitor of nuclear factor-κB (NF-κB), decreased the synergistic effects of AFS. In addition, AFS in combination with rIFN-γ increased the phosphorylation of p38 and c-Jun N-terminal kinase (JNK) but not extracellular signal-regulated kinase. However, AFS had no effect on phosphorylation of mitogen-activated protein kinases by itself. The p38 inhibitor SB203580 or the JNK inhibitor SP600125 inhibited the AFS-induced NO and TNF-α production. When AFS was used in combination with rIFN-γ, there was a co-operative activation of NF-κB and receptor-interacting protein 2 (Rip2)/IκB kinase (IKK)-β. Our results indicate that AFS increases the production of NO and TNF-α through the activation of Rip2/IKK-β in rIFN-γ-primed macrophages.

Effects of flavonoids and other polyphenols on inflammation

Flavonoids are a family of polyphenolic compounds which are widespread in nature (vegetables) and are consumed as part of the human diet in significant amounts. There are other types of polyphenols, including, for example, tannins and resveratrol. Flavonoids and related polyphenolic compounds have significant antiinflammatory activity, among others. This short review summarizes the current knowledge on the effects of flavonoids and related polyphenolic compounds on inflammation, with a focus on structural requirements, the mechanisms involved, and pharmacokinetic considerations. Different molecular (cyclooxygenase, lipoxygenase) and cellular targets (macrophages, lymphocytes, epithelial cells, endothelium) have been identified. In addition, many flavonoids display significant antioxidant/radical scavenging properties. There is substantial structural variation in these compounds, which is bound to have an impact on their biological profile, and specifically on their effects on inflammatory conditions. However, in general terms there is substantial consistency in the effects of these compounds despite considerable structural variations. The mechanisms have been studied mainly in myeloid cells, where the predominant effect is an inhibition of NF-κB signaling and the downregulation of the expression of proinflammatory markers. At present there is a gap in knowledge of in vitro and in vivo effects, although the pharmacokinetics of flavonoids has advanced considerably in the last decade. Many flavonoids have been studied for their intestinal antiinflammatory activity which is only logical, since the gastrointestinal tract is naturally exposed to them. However, their potential therapeutic application in inflammation is not restricted to this organ and extends to other sites and conditions, including arthritis, asthma, encephalomyelitis, and atherosclerosis, among others.

Intracoronary genistein acutely increases coronary blood flow in anesthetized pigs through beta-adrenergic mediated nitric oxide release and estrogenic receptors

Various studies have suggested that the phytoestrogen genistein has beneficial cardioprotective and vascular effects. However, there has been scarce information regarding the primary effect of genistein on coronary blood flow and its mechanisms including estrogen receptors, autonomic nervous system, and nitric oxide (NO). The present study was planned to determine the primary effect of genistein on coronary blood flow and the mechanisms involved. In anesthetized pigs, changes in left anterior descending coronary artery caused by intracoronary infusion of genistein at constant heart rate and arterial pressure were assessed using ultrasound flowmeters. In 25 pigs, genistein infused at 0.075 mg/min increased coronary blood flow by about 16.3%. This response was graded in a further five pigs by increasing the infused dose of the genistein between 0.007 and 0.147 mg/min. In the 25 pigs, blockade of cholinergic receptors (iv atropine; five pigs) and alpha-adrenergic receptors (iv phentolamine; five pigs) did not abolish the coronary response to genistein, whose effects were prevented by blockade of beta(2)-adrenergic receptors (iv butoxamine; five pigs), nitric oxide synthase (intracoronary N(omega)-nitro-L-arginine methyl ester; five pigs) and estrogenic receptors (ERs; ERalpha/ERbeta; intracoronary fulvestrant; five pigs). In porcine aortic endothelial cells, genistein induced the phosphorylation of endothelial nitric oxide synthase and NO production through ERK 1/2, Akt, and p38 MAPK pathways, which was prevented by the concomitant treatment by butoxamine and fulvestrant. In conclusion, genistein primarily caused coronary vasodilation the mechanism of which involved ERalpha/ERbeta and the release of NO through vasodilatory beta(2)-adrenoreceptor effects.

Phytoestrogens: perpetrators or protectors?

Phytoestrogens are estrogen-like substances produced by plants that account for some of the constituents present in vegetation that may be responsible for the health benefits of a diet rich in fruit and vegetables. Phytoestrogens have a plethora of different actions that they are capable of exerting on cellular metabolism. This review will focus on some of the major non-estrogen receptor-mediated cellular effects used by phytoestrogens and will draw attention to the fact that while they may have a number of beneficial effects, particularly in offering a protective effect against some hormone-dependent cancers, such as breast and prostate cancer, they may also have possible unfavorable effects by interfering with the functioning of normal cellular activities such as receptor-mediated signal transduction and DNA replication, as well as being genotoxic, mutagenic and promoting the proliferation of some cancer cells.

Effect of genistein and raloxifene on vascular dependent platelet aggregation

We checked the hypothesis whether the non-classical estrogen receptor modulators genistein and raloxifene could affect platelet aggregation through their direct effect on vascular tissue by regulating the synthesis of vasoactive compounds. In rat aortic strips, 10nM genistein or 10nM raloxifene significantly increased nitric oxide synthesis, event prevented by ICI182780. Both agents exhibited an antiaggregatory action, dependent on the nitric oxide release from vascular tissue, since preincubation of aortic strips with L-NAME partially and completely suppressed the inhibition of platelet aggregation induced by genistein or raloxifene respectively. The phytoestrogen enhanced phospholipase A(2) and prostacyclin release into the incubation medium. Indomethacin reduced in half the inhibition of platelet aggregation elicited by genistein. Finally, genistein or raloxifene also inhibited platelet aggregation in aortic strips from ovariectomized rats. In conclusion, genistein and raloxifene exhibit an antiplatelet activity through their direct action on vascular tissue, in rats with or without ovarian activity.

Endomorphin 1 activates nitric oxide synthase 2 activity and downregulates nitric oxide synthase 2 mRNA expression

Endomorphins 1 and 2 are newly discovered opioid tetrapeptides whose structure is more resistant to enzymatic degradation than that of other opioid peptides. Endomorphins 1 and 2 are considered as endogenous ligands with a high affinity for mu receptors. A number of studies have shown that opioid peptides per se can induce release of nitric oxide from rodent and human immune cells. Endomorphins seemed to be involved in the process of vasodilatation by stimulating release of nitric oxide. In our study we stimulated in vitro J774 macrophages with different concentrations of endomorphin 1 or 2 for measuring nitric oxide release and nitric oxide synthase 2 (NOS 2) mRNA expression. Results showed that 48 h incubation did not enhance nitric oxide release when measured with the Griess method. On the other hand, using real-time amperometric detection of nitric oxide release shortly after challenge with endomorphins, we showed that only 10(-6) M endomorphin 1 was able to stimulate nitric oxide release from a J774 macrophage cell line by activation of NOS 2 isoenzyme. The peak release was 1000-1500 s after stimulation and was in the range of nitric oxide release stimulated with 10 microg/ml lipopolysaccharide. In contrast to this, endomorphin 2 failed to induce nitric oxide release in all tested concentrations. Using a specific inhibitor of nitric oxide synthase 2 (N-(3-[aminomethyl]benzyl)acetamidine, 1400W) we eliminated the stimulatory effect of endomorphin 1 on nitric oxide release. The expression of mRNA for NOS 2 in J774 macrophages, after 30 min incubation with either lipopolysaccharide or 10(-6) M endomorphin 1 was not upregulated. As expected, lipopolysaccharide induced de novo NOS 2 transcription within 4 h. At the same time, in contrast to lipopolysaccharide, mRNA expression of cells treated with endomorphin 1 was downregulated. Since a mu-opioid receptor specific antagonist beta-funaltrexamine hydrochloride inhibited nitric oxide release from endomorphin 1-treated cells, the effect seemed to be mu-opioid receptor mediated.