Anti-inflammatory Potential of Quercetin-3-O-β-D-(“2”-galloyl)-glucopyranoside and Quercetin Isolated from Diospyros kaki calyx via Suppression of MAP Signaling Molecules in LPS-induced RAW 264.7 Macrophages

Anti-Inflammatory, Antioxidant, and Genoprotective Effects of Callus Cultures Obtained from the Pulp of Malus pumila cv Miller (Annurca Campana Apple)

Apples are rich in phytochemicals useful for human health. However, environmental factors can greatly affect the accumulation of these compounds. To face this problem, the callus culture technique was used to obtain large quantities of phytochemicals. Specifically, two callus cultures were obtained from ripe Annurca apple pulp (Malus pumila cv Miller) and cultivated under different light conditions: darkness and an 18-h photoperiod. The hydro-alcoholic extracts from the calli underwent analysis using GC-MS, GC-FID, and HPLC-DAD-ESI-MSn to determine the qualitative and quantitative content of phenolic and triterpenic acids. The study revealed the predominant presence of triterpenic compounds in both calli. Furthermore, we investigated their radical scavenging and antioxidant activities through DPPH, ABTS, ORAC assays, and lipoxygenase inhibition activity. Genoprotection was evaluated via nicking assay, and the anti-inflammatory effect was investigated via Griess assay on LPS-injured murine macrophages. All the analyses performed were compared with peel and pulp hydroalcoholic extracts. The results showed that both calli primarily show anti-inflammatory activity and moderate antioxidant effect and can protect DNA against oxidative stimuli. This data encouraged further research aimed at utilizing callus as a bioreactor to produce secondary metabolites for use in preventive and therapeutic applications to combat acute or chronic age-associated diseases.

In vitro evaluation of the immunomodulatory activity of the nutraceutical formulation AminoDefence

Immune system (IS) functionality is warranted by inter-dependent processes that balance body defences without exceeding in inflammation. An ideal nutraceutical approach should sustain the protective IS activity while controlling inflammation. The potential immunomodulatory activity of the food supplement (FS) AminoDefence was studied in resting macrophages RAW264.7 and following stimulation of bacterial- and viral-associated inflammation trough LPS and PolyI:C treatments, respectively. In unstimulated macrophages, the formulation exerted a dose-dependent immunostimulant activity by up-regulating NO, IL-6, TNF-α and MCP-1 release, while it dampened the aberrant release of these factors induced by pro-inflammatory stimuli. Exploring the contribution of single components Echinacea purpurea (E. purpurea) extract and quercetin, used at proportional concentrations than in whole formulation, a more pronounced immunostimulant effect was observed for E. purpurea, and an anti-inflammatory activity for quercetin. Hence, AminoDefence exerts an immunomodulatory activity in macrophages by effectively stimulating a protective inflammatory response and limiting it in cases of excessive inflammation.

Flavonoid diversity and roles in the lipopolysaccharide-mediated inflammatory response of monocytes and macrophages

Targeting lipopolysaccharide (LPS)/toll-like receptor 4 signaling in mononuclear phagocytes has been explored for the treatment of inflammation and inflammation-related disorders. However, only a few key targets have been translated into clinical applications. Flavonoids, a class of ubiquitous plant secondary metabolites, possess a privileged scaffold which serves as a valuable template for designing pharmacologically active compounds directed against diseases with inflammatory components. This perspective provides a general overview of the diversity of flavonoids and their multifaceted mechanisms that interfere with LPS-induced signaling in monocytes and macrophages. Focus is placed on flavonoids targeting MD-2, IκB kinases, c-Jun N-terminal kinases, extracellular signal-regulated kinase, p38 MAPK and PI3K/Akt or modulating LPS-related gene expression.

Anti-Allergic Effects of Quercetin and Quercetin Liposomes in RBL-2H3 Cells

BACKGROUND

Quercetin is a kind of flavonoid with important bioactivities, such as hypoglycemic, antioxidant, anti-inflammatory, and anti-allergic properties. Although it is unstable, it is worth exploring how to better exert its anti-allergic effect.

OBJECTIVE

The current study aimed to elucidate the anti-allergic effect of quercetin liposomes on RBL-2H3 cells in vitro.

METHODS

Quercetin liposomes were prepared to improve the anti-allergic activity of quercetin through a green thin-film dispersion method. We compared the anti-allergic effects of quercetin and quercetin liposomes in RBL-2H3 cells. The anti-allergic activity of the quercetin liposomes was evaluated by the level of β-hexosaminidase, histamine, Ca2+, IL-4, IL-8, and MCP-1.

RESULTS

The results showed that quercetin liposomes could significantly restrain the release of β-hexosaminidase and histamine, calcium influx, and the expression of inflammatory factors, whose effect is stronger than quercetin.

CONCLUSION

Collectively, our research suggests that the quercetin liposome can be used as a potential allergy antagonist.

Unveiling major ethnopharmacological aspects of genus Diospyros in context to its chemical diversity: A comprehensive overview

Diospyros species (DS), "Ebenaceae," were known for their therapeutic uses in folk medicine since days of yore. Thereafter, scientific evidence related their health benefits to a myriad of chemical classes, for instance, naphthoquinones, flavonoids, tannins, coumarins, norbergenin derivatives, sterols, secoiridoids, sesquiterpenes, diterpenoids, triterpenoids, volatile organic compounds (VOCs), and carotenoids. The available literature showed that more than 200 compounds were isolated and identified via spectroscopic techniques. Many pharmacological activities of DS have been previously described, such as antioxidant, neuroprotective, antibacterial, antiviral, antiprotozoal, antifungal, antiinflammatory, analgesic, antipyretic and cosmeceutical, investigated, and confirmed through versatile in vitro and in vivo assays. Previous studies proved that genus Diospyros is a rich reservoir of valuable bioactive compounds. However, further comparative studies among its different species are recommended for more precise natural source-based drug discovery and clinical application. Accordingly, this review is to recall the chemical abundance and diversity among different members of genus Diospyros and their ethnopharmacological and pharmacological uses. PRACTICAL APPLICATIONS: Practically, providing sufficient background on both secondary metabolites divergence and pharmacological properties of genus Diospyros has many fruitful aspects. As demonstrated below, extracts and many isolated compounds have significant curative properties, which can lead to the discovery of pharmaceutically relevant alternative substitutes to conventional medicine. Consequently, molecular docking on various receptors can be applied. On the grounds, Naoxinqing tablets, a standardized herbal product containing D. kaki leaves extract, have been patented and recorded in Chinese Pharmacopeia as an approved Traditional Chinese Medicine (TCM) for the treatment of cerebro- and cardiovascular diseases, although the underlying mechanism remains under advisement. Moreover, the antimicrobial applications of DS are of considerable concern; since the widespread use of antibiotics resulted in different forms of bacterial resistance, hence, limiting and compromising effective treatment. In addition, as a result of contemporary rampant memory disorders, neuroprotective activities of different extracts of DS became of great emphasis.

Natural acylated flavonoids: their chemistry and biological merits in context to molecular docking studies

Acylated flavonoids are widely distributed natural dietary bioactives with several health attributes. A large diversity of acylated flavonoids with interesting biological potentialities were reported. Of these, 123 compounds with potential antimicrobial, antiparasitic, anti-inflammatory, anti-nociceptive, analgesic and anti-complementary effects were selected from several databases. Based upon these data, the possible mechanistic evidence for their effects were reported. Generally, aromatic acyls i.e., galloyl derivatives appeared to improve efficacy through enhancement of the binding affinities to molecular targets due to plenty of donating and accepting centers. Docking simulations conducted by Molecular Operating Environment (MOE) of acylated flavonoids revealed that compound 12 is at the top of the list into the antibacterial target DNA gyrase subunit B (GyrB), from E. coli, followed by compounds 10, 4 and 23. Compounds 81, 88, 96, 92, 99, 100, 102 and 103 have the strongest binding affinities into Human matrix metallopeptidase (MMP) 2 and 9 catalytic domains. Compound 103 exerted the most balanced predicted dual MMP-2/MMP-9 inhibition action. Compound 95 recorded the strongest binding affinity into metabotropic glutamate receptor (mglur1) with the lowest energy conformer. The data presented in this review suggests that these candidate acylated flavonoids ought to be considered in future drug developments especially as anti-inflammatory and antimicrobial agents.

Quercitrin protects human bronchial epithelial cells from oxidative damage

Chronic obstructive pulmonary disease (COPD) is mainly caused by cigarette smoking (CS), with oxidative stress being one key component during its pathogenesis. This study aimed to investigate the effects of quercitrin (QE) on cigarette smoke extract (CSE)-induced cell apoptosis and oxidative stress in human bronchial epithelial cells (HBECs) and its underlying mechanism. HBECs were treated with 2% CSE for 24 h to establish in vitro COPD cellular models. CCK-8 assay and flow cytometry analysis were performed to evaluate cell viability and apoptosis, respectively. Western blotting was applied to examine protein levels and ELISA kits were used to examine contents of the indicated oxidant/antioxidant markers. The results demonstrated that CSE promoted apoptosis and suppressed viability of HBECs and QE reversed these effects. CSE caused increase in T-AOC, superoxide dismutase, and glutathione (GSH) peroxidase contents and decrease in MDA, reactive oxygen species , and GSH contents in HBECs, which were rescued by QE treatment. The CSE-induced Nrf2 nuclear translocation and elevation of NAD(P)H: quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (HO-1) expression were also reversed by QE in HBECs. The mitogen-activated protein kinase (MAPK) signaling was activated by CSE and further suppressed by QE in HBECs. Collectively, QE exerts a protective role in HBECs against cell apoptosis and oxidative damage via inactivation of the Nrf2/HO-1/NQO1 pathway and the MAPK/ERK pathway.

Enhanced water dispersibility and Caco-2 cell monolayer permeability of quercetin by complexation with casein hydrolysate

Although quercetin (Que) has many beneficial therapeutic effects on the human body, its oral bioavailability is poor because of its low water solubility. Herein, we describe the preparation of casein hydrolysate (Pep_cas ) and its use as a dispersant to enhance the water dispersibility of Que resulting in an improvement of its bioavailability. By complexation with Pep_cas , the apparent solubility of Que in the complex (Que@Pep_cas ) was significantly increased under acidic and neutral conditions. Que@Pep_cas was pre-digested in vitro using a simulated digestive juice, and a Caco-2 cell monolayer permeation assay was performed to evaluate the oral bioavailability of Que. The cumulative amount of Que that permeated the monolayer using Que@Pep_cas after 8, 16, and 24 h was increased compared with a blank sample (Que@Blank), and the apparent permeation coefficient P_app of Que@Pep_cas was approximately 2.6-fold better than that of Que@Blank. PRACTICAL APPLICATION: Pep_cas can be used as a high absorption supplement and food additive, and our Pep_cas complexation technique should be widely applicable to not only Que but also to other poorly water-soluble substances.

Natural Products for the Prevention and Control of the COVID-19 Pandemic: Sustainable Bioresources

Background: The world has been unprecedentedly hit by a global pandemic which broke the record of deadly pandemics that faced humanity ever since its existence. Even kids are well-versed in the terminologies and basics of the SARS-CoV-2 virus and COVID-19 now. The vaccination program has been successfully launched in various countries, given that the huge global population of concern is still far behind to be vaccinated. Furthermore, the scarcity of any potential drug against the COVID-19-causing virus forces scientists and clinicians to search for alternative and complementary medicines on a war-footing basis. Aims and Objectives: The present review aims to cover and analyze the etiology and epidemiology of COVID-19, the role of intestinal microbiota and pro-inflammatory markers, and most importantly, the natural products to combat this deadly SARS-CoV-2 virus. Methods: A primary literature search was conducted through PubMed and Google Scholar using relevant keywords. Natural products were searched from January 2020 to November 2020. No timeline limit has been imposed on the search for the biological sources of those phytochemicals. Interactive mapping has been done to analyze the multi-modal and multi-target sources. Results and Discussion: The intestinal microbiota and the pro-inflammatory markers that can serve the prognosis, diagnosis, and treatment of COVID-19 were discussed. The literature search resulted in yielding 70 phytochemicals and ten polyherbal formulations which were scientifically analyzed against the SARS-CoV-2 virus and its targets and found significant. Retrospective analyses led to provide information about 165 biological sources that can also be screened if not done earlier. Conclusion: The interactive analysis mapping of biological sources with phytochemicals and targets as well as that of phytochemical class with phytochemicals and COVID-19 targets yielded insights into the multitarget and multimodal evidence-based complementary medicines.

Helicobacter pylori cholesterol-α-glucosyltransferase manipulates cholesterol for bacterial adherence to gastric epithelial cells

Helicobacter pylori infection is associated with several gastrointestinal diseases, including gastritis, peptic ulcers, and gastric cancer. Infection of cells with H. pylori is dependent on lipid rafts, which are cholesterol-rich microdomains located in the cell membrane. H. pylori cholesterol-α-glucosyltransferase (CGT) catalyzes the conversion of membrane cholesterol to cholesteryl glucosides, which can be incorporated into the bacterial cell wall, facilitating evasion from immune defense and colonization in the host. However, the detailed mechanisms underlying this process remain to be explored. In this study, we discovered for the first time that H. pylori CGT could promote adherence to gastric epithelial cells in a cholesterol-dependent manner. Externalization of cell membrane phosphatidylserine (PS) is crucial for enhancement of binding of H. pylori to cells by CGT and for cytotoxin-associated gene A (CagA)-induced pathogenesis. Furthermore, exogenous cholesterol interferes with the actions of H. pylori CGT to catalyze cellular cholesterol, which impedes bacterial binding to cells and attenuates subsequent inflammation, indicating that the initial attachment of H. pylori to cells is closely dependent on host cholesterol. These results provide evidence that CGT contributes to H. pylori infectivity and it may serve as a key target for the treatment of H. pylori-associated diseases.

Triterpene Acids from Mesona procumbens Exert Anti-inflammatory Effects on LPS-Stimulated Murine Macrophages by Regulating the MAPK Signaling Pathway

Five new triterpene acids, mesonaic acids A-C (1-3), 2α,3α,19α-trihydroxy-24-nor-4(23),12-oleanadien-28-oic acid (4), and 3α,19α,22α-trihydroxy-2-oxo-12-ursen-28-oic acid (5), and 10 known triterpene acid compounds (6-15) were isolated from a methanolic extract of Mesona procumbens. Triterpenes 1-3 possess unusual hexacyclic skeletons with a 13α,27-cyclopropane ring. Regarding their anti-inflammatory activity, compounds 1-3, 6, and 7 inhibited NO production with EC₅₀ values lower than 15 μM, which were better than that of the positive control quercetin. Compounds 1-3, 6, and 7 markedly decreased levels of the inducible iNOS and COX-2 proteins in macrophages by inhibiting the activation of NF-κB through interference with the MAPK signaling pathway. Based on these data, compounds 1-3, 6, and 7 have great potential as NO inhibitors.

Changes in the extracted amounts and seasonally variable constituents of Diospyros kaki at different growth stages

Persimmon Calyx is a crude drug derived from the persistent calyx of mature fruit of Diospyros kaki Thunberg (Ebenaceae) and is used for the treatment of intractable hiccups. Although there are several reports on the isolation of constituents from Persimmon Calyx, its active constituents have not been elucidated. In this study, by focusing on the medicinal part of Persimmon Calyx, calyx on mature fruit of D. kaki, we examined the changes in the extraction amounts of 3 cultivars of D. kaki ('Hiratanenashi', 'Jiro', and 'Tonewase') to identify and quantify seasonally variable constituents during the maturation process by analysing their chemical compositions. We found that the extraction weight of the calyx, fruit of persimmons, and total tannin content in calyxes were significantly increased during maturation. Lupeol (1), betulinic acid (2), pomolic acid (3), ursolic acid (4), β-sitosterol (5), rotungenic acid (6), barbinervic acid (7), catechin (8), gallocatechin (9), and sucrose (10) were identified in the calyx of D. kaki. Compounds 1, 6, and 7 were isolated from Persimmon Calyx for the first time. Moreover, the isolated compounds (1-7) and their analogue (oleanolic acid) were quantitatively analysed, and the results showed that the amounts of 4 and oleanolic acid were reduced during maturation, whereas that of 2, 3, 6, and 7 were increased.

Development of Triggerable, Trackable, and Targetable Carbon Monoxide Releasing Molecules

Carbon monoxide (CO) is a gaseous signaling molecule produced in humans via the breakdown of heme in an O2-dependent reaction catalyzed by heme oxygenase enzymes. A long-lived species relative to other signaling molecules (e.g., NO, H2S), CO exerts its physiological effects via binding to low-valent transition metal centers in proteins and enzymes. Studies involving the administration of low doses of CO have shown its potential as a therapeutic agent to produce vasodilation, anti-inflammatory, antiapoptotic, and anticancer effects. In pursuit of developing tools to define better the role and therapeutic potential of CO, carbon monoxide releasing molecules (CORMs) were developed. To date, the vast majority of reported CORMs have been metal carbonyl complexes, with the most well-known being Ru2Cl4(CO)6 (CORM-2), Ru(CO)3Cl(glycinate) (CORM-3), and Mn(CO)4(S2CNMe(CH2CO2H)) (CORM-401). These complexes have been used to probe the effects of CO in hundreds of cell- and animal-based experiments. However, through recent investigations, it has become evident that these reagents exhibit complicated reactivity in biological environments. The interpretation of the effects produced by some of these complexes is obscured by protein binding, such that their formulation is not clear, and by CO leakage and potential redox activity. An additional weakness with regard to CORM-2 and CORM-3 is that these compounds cannot be tracked via fluorescence. Therefore, it is unclear where or when CO release occurs, which confounds the interpretation of experiments using these molecules. To address these weaknesses, our research team has pioneered the development of metal-free CORMs based on structurally tunable extended flavonol or quinolone scaffolds. In addition to being highly controlled, with CO release only occurring upon triggering with visible light (photoCORMs), these CO donors are trackable via fluorescence prior to CO release in cellular environments and can be targeted to specific cellular locations.In the Account, we highlight the development and application of a series of structurally related flavonol photoCORMs that (1) sense characteristics of cellular environments prior to CO release; (2) enable evaluation of the influence of cytosolic versus mitochondrial-localized CO release on cellular bioenergetics; (3) probe the cytotoxicity and anti-inflammatory effects of intracellular versus extracellular CO delivery; and (4) demonstrate that albumin delivery of a photoCORM enables potent anticancer and anti-inflammatory effects. A key advantage of using triggered CO release compounds in these investigations is the ability to examine the effects of the molecular delivery vehicle in the absence and presence of localized CO release, thus providing insight into the independent contributions of CO. Overall, flavonol-based CO delivery molecules offer opportunities for triggerable, trackable, and targetable CO delivery that are unprecedented in terms of previously reported CORMs and, thus, offer significant potential for applications in biological systems.

In vitro anti-inflammatory properties of Smilax campestris aqueous extract in human macrophages, and characterization of its flavonoid profile

ETHNOPHARMACOLOGICAL RELEVANCE

Extracts of Smilax campestris Griseb (Smilacaceae) have been employed in the treatment of several inflammatory diseases as a traditional herbal medicine. However, the cellular and molecular mechanisms involved in the observed effects remain elusive. Macrophages are known to play a central role in inflammatory responses. These cells are activated in response to a diversity of danger signals and produce several mediators of inflammation that eventually regulate the immune response. For all the above mentioned, scientific evidence is required to support the popular use of S. campestris.

AIM OF THE STUDY

We aimed to investigate the anti-inflammatory effect of S. campestris aqueous extract (SME) in activated THP-1 human macrophages, on the production of some mediators of inflammation and oxidative stress in order to provide scientific support for its popular use.

MATERIALS AND METHODS

The characterization of SME was assessed by HPLC-MS/MS. The production of the pro-inflammatory cytokines and chemokines was evaluated by ELISA. The activity of metalloproteases was evaluated by zymography. The subcellular localization of the NF-κB transcription factor was analysed by Western blot. The superoxide anion and glutathione levels were assessed by flow cytometry. The cytotoxicity induced by SME in THP-1 macrophages was also investigated by the LDH release test.

RESULTS

In the present study, we have identified catechin and glycosylated derivatives of quercetin (quercetin-3-O-glucoside, quercetin-3-O-galactoside, rutin and quercetin-3-rhamnoside) as major components of the aqueous SME. We found that SME significantly decreased the production of the pro-inflammatory cytokines tumour necrosis factor (TNF)- α, interleukin (IL)-1β, IL-6, IL-8 and monocyte chemoattractant protein (MCP)-1 and the activity of the metalloproteinase (MMP)-9, in lipopolysaccharide-activated macrophages derived from the monocytic cell line THP-1. Furthermore, SME diminished the expression of NF-κB p65 subunit in the nuclear fraction. In addition, SME decreased the production of superoxide anion in THP-1 macrophages, without altering the levels of reduced glutathione.

CONCLUSION

These results suggest that SME exerts its anti-inflammatory effects in human activated macrophages by inhibiting the production of pro-inflammatory cytokines, matrix metalloproteinases and the NF-κB transcription factor pathway along with a reduction of oxidative stress mediators. Moreover, catechin and glycosylated derivatives of were identified by HPLC-MS/MS in SME. Our findings provide scientific support for the traditional use of the S. campestris extracts.

Isorhamnetin Has Potential for the Treatment of Escherichia coli-Induced Sepsis

Isorhamnetin is a flavonoid that is abundant in the fruit of Hippophae rhamnoides L. It is widely studied for its ability to modulate inflammatory responses. In this study, we evaluated the potential of isorhamnetin to prevent gram-negative sepsis. We investigated its efficacy using an Escherichia coli-induced sepsis model. Our study reveals that isorhamnetin treatment significantly enhances survival and reduces proinflammatory cytokine levels in the serum and lung tissue of E. coli-infected mice. Further, isorhamnetin treatment also significantly reduces the levels of aspartate aminotransferase, alanine amino transferase and blood urea nitrogen, suggesting that it can improve liver and kidney function in infected mice. Docking studies reveal that isorhamnetin binds deep in the hydrophobic binding pocket of MD-2 via extensive hydrophobic interactions and hydrogen bonding with Tyr102, preventing TLR4/MD-2 dimerization. Notably, binding and secreted alkaline phosphatase reporter gene assays show that isorhamnetin can interact directly with the TLR4/MD-2 complex, thus inhibiting the TLR4 cascade, which eventually causes systemic inflammation, resulting in death due to cytokine storms. We therefore presume that isorhamnetin could be a suitable therapeutic candidate to treat bacterial sepsis.

Quercetin and Quercitrin Attenuates the Inflammatory Response and Oxidative Stress in LPS-Induced RAW264.7 Cells: In Vitro Assessment and a Theoretical Model

BACKGROUND

Nowadays, atmospheric pollutants, ultraviolet rays, and other factors cause the imbalance of cell redox, resulting in skin oxidative damage. There is an interaction between inflammatory response and oxidative stress, which often involve networks of reactions and serve to amplify each other. Quercetin and quercitrin, with strong antioxidant and anti-inflammatory properties, were widely applied in cardiovascular disease, osteoporsis, pulmonary disease, etc. However, the regulation mechanism of quercetin and quercitrin on various inflammatory skin diseases is still not clear.

PURPOSE

In this study, quercetin and quercitrin were used to investigate whether they had anti-inflammatory and anti-ROS effects. Besides, theoretical calculation method was also adopted to preliminarily explore the mechanism of the anti-inflammatory and antioxidant effects of these two substances.

METHODS

CCK-8 assay was employed to investigate the cytotoxicity. The concentration of NO measured by Griess Reaction System. Moreover, the inflammatory factors (TNF-α, IL-1β, and IL-6) were reduced in LPS-stimulated RAW264.7 cells were tested by ELISA kits. The trend of ROS changes was detected by DCFH-DA method. Finally, the mechanism of the anti-inflammatory and antioxidant effects of these two substances was carried out by DMol3 package in Materials Studio.

RESULTS

CCK-8 assay results guided that the safe concentration of quercetin and quercitrin was lower than 15.0 μg/mL and 22.4 μg/mL, respectively. Also, the concentration of NO could significantly be inhibited by quercetin and quercitrin. Besides, the ELISA results showed that TNF-α, IL-1β, and IL-6 were reduced in LPS-stimulated RAW264.7 cells after interfering with quercetin and quercitrin. The trend of ROS changes was similar to that of inflammatory factors. Finally, the theoretical calculation illustrated that the oxygen atom on B rings may be the main site of electron cloud density changes, which may suggest a possible mechanism for the anti-inflammatory and ROS scavenging effects of quercetin and quercitrin.

CONCLUSIONS

This experiment shows that LPS can induce the overactivating of macrophages and the activated macrophages can subsequently induce inflammatory storms and oxidative stress. Both quercetin and quercitrin can inhibit LPS-induced macrophage inflammation and oxidative stress by experiment and theoretical calculations.

Extracellular vs Intracellular Delivery of CO: Does It Matter for a Stable, Diffusible Gasotransmitter?

Carbon monoxide (CO) is a gasotransmitter produced in humans. An essential unanswered question in the design of carbon monoxide releasing molecules (CORMs) is whether the delivery molecule should be localized extra- or intracellularly to produce desired biological effects. Herein we show that extracellular CO release is less toxic and is sufficient to produce an anti-inflammatory effect similar to that of intracellular CO release at nanomolar concentrations. This information is valuable for the design of CORMs.

Targeting pro-senescence mitogen activated protein kinase (Mapk) enzymes with bioactive natural compounds

Aging is a multifactorial universal process characterized by a gradual decrease in physiological and biochemical functions. Given that life expectancy is on the rise, a better understanding of molecular mechanisms of the aging process is necessary in order to develop anti-aging interventions. Uncontrolled cellular senescence promotes persistent inflammation and accelerates the aging process by decreasing tissue renewal, repair and regeneration. Senescence of immune cells, immunesenescence, is another hallmark of aging. Targeting pro-senescent enzymes increases survival and therefore the lifespan. Although the upregulation of Mitogen Activated Protein Kinases (MAPK) enzymes in aging is still controversial, increasing evidence shows that dysregulation of those enzymes are associated with biological processes that contribute to aging such as irreversible senescence. In this manuscript components of the MAPK pathway will be summarized, including extracellular signal-regulated kinase 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38, as well as natural flavonoids, phenolic and diterpenoids with anti-senescence activity that shows positive effects on longevity and MAPK inhibition. Although more studies using additional aging models are needed, we suggest that these selected natural bioactive compounds that regulate MAPK enzymes and reduce senescent cells can be potentially used to improve longevity and prevent/treat age-related diseases.

Shepherd's Purse Polyphenols Exert Its Anti-Inflammatory and Antioxidative Effects Associated with Suppressing MAPK and NF-κB Pathways and Heme Oxygenase-1 Activation

Shepherd's purse (Capsella bursa-pastoris (L.) Medik.), a wild herb as a traditional herbal medicine, has been proved with multiple healthy benefits. In this study, the chemical constituents of shepherd's purse were identified by UPLC-QTOF-MS/MS. The antioxidative and anti-inflammatory potential of shepherd's purse extract (SPE) were also investigated applying lipopolysaccharide- (LPS-) induced inflammation in RAW 264.7 macrophages and a carrageenan-induced mice paw edema model. Twenty-four chemical compounds were identified mainly including phenolic acids and flavonoids. The data also indicated SPE inhibited the productions of NO, PGE₂, TNF-α, and IL-6 stimulated with LPS. In addition, SPE inhibited the increase of reactive oxygen species (ROS) and upregulated the expression of heme oxygenase-1 (HO-1). We further found that SPE inhibited the phosphorylation of P38 MAPK and activation of NF-κB. In vivo mice model also indicated that SPE showed strong antioxidative and anti-inflammatory activity.

Quercetin inhibits LPS-induced macrophage migration by suppressing the iNOS/FAK/paxillin pathway and modulating the cytoskeleton

The natural flavonoid quercetin has antioxidant, anti-inflammatory, and anticancer effects. We investigated the effect of quercetin on lipopolysaccharide (LPS)-induced macrophage migration. Quercetin significantly attenuated LPS-induced inducible nitric oxide synthase (iNOS)-derived nitric oxide (NO) production in RAW264.7 cells without affecting their viability. Additionally, quercetin altered the cell size and induced an elongated morphology and enlarged the vacuoles and concentrated nuclei. Quercetin significantly disrupted the F-actin cytoskeleton structure. Furthermore, quercetin strongly inhibited LPS-induced macrophage adhesion and migration in a dose-dependent manner. Moreover, quercetin inhibited the LPS-induced expression of p-FAK, p-paxillin, FAK, and paxillin as well as the cytoskeletal adapter proteins vinculin and Tensin-2. Therefore, quercetin suppresses LPS-induced migration by inhibiting NO production, disrupting the F-actin cytoskeleton, and suppressing the FAK–paxillin pathway. Quercetin may thus have potential as a therapeutic agent for chronic inflammatory diseases.

Chronic diseases, inflammation, and spices: how are they linked?

Extensive research within the last several decades has revealed that the major risk factors for most chronic diseases are infections, obesity, alcohol, tobacco, radiation, environmental pollutants, and diet. It is now well established that these factors induce chronic diseases through induction of inflammation. However, inflammation could be either acute or chronic. Acute inflammation persists for a short duration and is the host defense against infections and allergens, whereas the chronic inflammation persists for a long time and leads to many chronic diseases including cancer, cardiovascular diseases, neurodegenerative diseases, respiratory diseases, etc. Numerous lines of evidence suggest that the aforementioned risk factors induced cancer through chronic inflammation. First, transcription factors NF-κB and STAT3 that regulate expression of inflammatory gene products, have been found to be constitutively active in most cancers; second, chronic inflammation such as pancreatitis, prostatitis, hepatitis etc. leads to cancers; third, activation of NF-κB and STAT3 leads to cancer cell proliferation, survival, invasion, angiogenesis and metastasis; fourth, activation of NF-κB and STAT3 leads to resistance to chemotherapy and radiation, and hypoxia and acidic conditions activate these transcription factors. Therefore, targeting these pathways may provide opportunities for both prevention and treatment of cancer and other chronic diseases. We will discuss in this review the potential of various dietary agents such as spices and its components in the suppression of inflammatory pathways and their roles in the prevention and therapy of cancer and other chronic diseases. In fact, epidemiological studies do indicate that cancer incidence in countries such as India where spices are consumed daily is much lower (94/100,000) than those where spices are not consumed such as United States (318/100,000), suggesting the potential role of spices in cancer prevention.

Diospyros kaki calyx inhibits immediate-type hypersensitivity via the reduction of mast cell activation

CONTEXT

Diospyros kaki L. (Ebenaceae) fruit is widely distributed in Asia and is known to exert anti-inflammatory and antithrombotic effects.

OBJECTIVE

We evaluated the inhibitory effect of aqueous extract of D. kaki calyx (AEDKC) on mast cell-mediated immediate-type hypersensitivity and underlying mechanism of action.

MATERIALS AND METHODS

For in vivo, ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) and immunoglobulin (Ig) E-mediated passive cutaneous anaphylaxis (PCA) models were used. In the ASA, AEDKC (1-100 mg/kg) was orally administered 3 times during 14 days. In the PCA, AEDKC was orally treated 1 h before the antigen challenge. The control drug dexamethasone was used to compare the effectiveness of AEDKC. For in vitro, IgE-stimulated RBL-2H3 cells and primary cultured peritoneal mast cells were used to determine the role of AEDKC (0.01-1 mg/mL).

RESULTS

Oral administration of AEDKC dose dependently suppressed rectal temperature decrease and increases in serum histamine, total IgE, OVA-specific IgE, and interleukin (IL)-4 in the ASA. In the PCA, AEDKC reduced Evans blue pigmentation. Compared to dexamethasone (10 mg/kg), AEDKC (100 mg/kg) showed similar inhibitory effects in vivo. AEDKC concentration dependently suppressed the release of histamine and β-hexosaminidase through the reduction of intracellular calcium in mast cells. In addition, AEDKC decreased the expression and secretion of tumour necrosis factor-α and IL-4 by the reduction of nuclear factor-κB. The inhibitory potential of AEDKC (1 mg/mL) was similar with dexamethasone (10 μM) in vitro.

CONCLUSIONS

We suggest that AEDKC may be a potential candidate for the treatment of mast cell-mediated allergic diseases.

Anticancer activity of calyx of Diospyros kaki Thunb. through downregulation of cyclin D1 via inducing proteasomal degradation and transcriptional inhibition in human colorectal cancer cells

BACKGROUND

Although it has been reported to contain high polyphenols, the pharmacological studies of the calyx of Diospyros kaki Thunb (DKC) have not been elucidated in detail. In this study, we elucidated anti-cancer activity and potential molecular mechanism of DKC against human colorectal cancer cells.

METHODS

Anti-cell proliferative effect of 70% ethanol extracts from the calyx of Diospyros kaki (DKC-E70) was evaluated by MTT assay. The effect of DKC-E70 on the expression of cyclin D1 in the protein and mRNA level was evaluated by Western blot and RT-PCR, respectively.

RESULTS

DKC-E70 suppressed the proliferation of human colorectal cancer cell lines such as HCT116, SW480, LoVo and HT-29. Although DKC-E70 decreased cyclin D1 expression in protein and mRNA level, decreased level of cyclin D1 protein by DKC-E70 occurred at the earlier time than that of cyclin D1 mRNA, which indicates that DKC-E70-mediated downregulation of cyclin D1 protein may be a consequence of the induction of degradation and transcriptional inhibition of cyclin D1. In cyclin D1 degradation, we found that cyclin D1 downregulation by DKC-E70 was attenuated in presence of MG132. In addition, DKC-E70 phosphorylated threonine-286 (T286) of cyclin D1 and T286A abolished cyclin D1 downregulation by DKC-E70. We also observed that DKC-E70-mediated T286 phosphorylation and subsequent cyclin D1 degradation was blocked in presence of the inhibitors of ERK1/2, p38 or GSK3β. In cyclin D1 transcriptional inhibition, DKC-E70 inhibited the expression of β-catenin and TCF4, and β-catenin/TCF-dependent luciferase activity.

CONCLUSIONS

Our results suggest that DKC-E70 may downregulate cyclin D1 as one of the potential anti-cancer targets through cyclin D1 degradation by T286 phosphorylation dependent on ERK1/2, p38 or GSK3β, and cyclin D1 transcriptional inhibition through Wnt signaling. From these findings, DKC-E70 has potential to be a candidate for the development of chemoprevention or therapeutic agents for human colorectal cancer.