Inhibition Of Nitric Oxide Production Research Articles

Protease inhibitor from Libidibia ferrea seeds attenuates inflammatory and nociceptive responses in mice

Ethnopharmacological relevanceLibidibia ferrea (Mart. ex. Tul.) L.P. Queiroz is a Brazilian native tree locally known as jucá and pau-ferro, and it has been used in folk medicine for relieving, asthma, bronchitis, sore throat, rheumatism, enterocolitis and fever. The anti-inflammatory properties of L. ferrea were confirmed for its stem, fruit, leaves, bark and seeds extracts, however little is known about the natural compounds that may be associated with that response. Aim of this studyIn a normal physiological condition, many enzymes play an important role in catalyzing biological functions. Among them, proteases are of great interest. Although they take part of many biological systems, as the inflammatory process, when deregulated, proteases may cause system malfunctions, such as under- or overproduction of cytokines, or immune cells activation. Thus, protease inhibitors prevent these immune responses by regulating proteases. The objective of this study was to evaluate the anti-inflammatory and anti-nociceptive response of a protease inhibitor purified from L. ferrea seeds (LfTI). Materials and methodsIn vitro (5, 50 and 250 μg/mL of LfTI) and in vivo (0.6, 3 e 15 mg/kg of LfTI) assays were performed. Male Swiss mice weighing 18–25 g were used for cell harvesting and for the in vivo assays. The anti-inflammatory activity was analyzed in vitro by macrophage cytotoxicity, hydrogen peroxide (H2O2) production, and cell adhesion assays; and in vivo by leukocyte recruitment, nitric oxide (NO) production, vascular permeability, paw edema and mast cell degranulation assays. The anti-nociceptive activity was evaluated through abdominal writhing test induced by acetic acid and formalin sensitization. ResultsOur results showed that, in vitro, LfTI is not cytotoxic. Also, LfTI (50 μg/mL) inhibited macrophage H2O2 production (48.2%), and adhesion (48.4%). LfTI (0.6, 3 e 15 mg/kg) decreased polymorphonuclear cell recruitment dose-dependently, and it inhibited NO production (53%), vascular permeability (40.7%) and paw edema at 3 mg/kg at different time, but it did not inhibit mast cell degranulation. Besides, LfTI did not inhibit either the number of writhing or the licking time in the formalin test in the second phase (inflammatory). However, LfTI (3 mg/kg) inhibited licking time at the first phase (neurogenic) in the formalin sensitization (46.1%). ConclusionsOur results show that LfTI has anti-inflammatory and antinociceptive (neurogenic pain) effects, and these effects might be associated with the inhibition of inflammatory proteases and/or protease-activated receptors activation hindering.

Enhancement of the In Vitro Antitumor Effects of Berberine Chloride When Encapsulated within Small Extracellular Vesicles.

Berberine hydrochloride (BRB) is an isoquinoline alkaloid with promising anticancer efficacies. However, application of BRB had been hampered by its poor aqueous solubility, low gastrointestinal absorption, and rapid metabolism. The present study takes advantage of small extracellular vesicles (sEVs) to increase both stability and efficacy of BRB. sEVs from immature dendritic cells were produced and loaded with BRB. Proliferation, migration and Matrigel assay were performed, cycle arrest and nitric oxide (NO) production were evaluated in human breast cancer cell line (MDA-MB-231) and human umbilical vein endothelial cells (HUVECs). sEVs loaded with BRB formed a stable and homogenous population with a drug entrapment efficiency near to 42%. BRB loaded into sEVs was more potent than free BRB for MDA-MB-231 and endothelial proliferation, migration, and capillary-like formation in HUVECs. The mechanisms involved a blockade of cell cycle in G0/G1 phase, increased S phase and decreased of G2/M in MDA-MB-231 and HUVECs, and inhibition of NO production in HUVECs. Altogether, sEV-loaded BRB displayed higher effects than free BRB on different steps leading to its antitumor activity and anti-angiogenic properties in vitro. Thus, sEV formulation may be considered as an innovative approach and promising delivery of BRB to prevent tumorigenesis and angiogenesis.

Further sesquiterpenoids from Pittosporum qinlingense and their anti-inflammatory activity

Four new sesquiterpenoid glycoside esters, Pitqinlingoside N-Q (1–4), together with eleven known metabolites (5–15), were isolated from 95% EtOH extract of the twigs, fruits and leaves of P. qinlingense. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses, including IR, UV, HRMS, NMR and electronic circular dichroism spectra. Unusal glycoside esters are characterized by the presence of polyacylated β-D-fucopyranosyl and β-d-glucopyranosyl units. Pitqinlingoside N (1), O (2), P (3), boscialin (5) and arvoside C (6) showed significant nitric oxide production inhibition in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC50 values ranging from 1.58 to 28.74 μM. Structure-activity relationships of the isolated compounds are discussed.

Carbon monoxide-releasing molecule-401, a water-soluble manganese-based metal carbonyl, suppresses Prevotella intermedia lipopolysaccharide-induced production of nitric oxide in murine macrophages

Context Many reports in the literature have suggested the therapeutic value of carbon monoxide-releasing molecules (CORMs) against various diseases. However, to date, little is known about their possible influence on periodontal disease. Objective This study was performed to investigate the influence of CORM-401 on the generation of nitric oxide (NO) in murine macrophage cells activated with lipopolysaccharide (LPS) derived from Prevotella intermedia, a pathogen associated with periodontal disease. Materials and methods LPS was isolated by the hot phenol-water method. Culture supernatants were analyzed for NO. Real-time PCR and immunoblotting were conducted to quantify mRNA and protein expression, respectively. NF-κB-dependent SEAP levels were estimated by reporter assay. DNA-binding of NF-κB was also analyzed. Results CORM-401 caused an apparent suppression of NO production through inhibition of iNOS at both the mRNA and protein levels in RAW264.7 cells stimulated with P. intermedia LPS. CORM-401 upregulated the expression of both the HO-1 gene and its protein in LPS-activated cells, and treatment with the HO-1 inhibitor significantly reversed the attenuating influence of CORM-401 against LPS-induced generation of NO. CORM-401 caused an apparent attenuation of NF-κB-dependent SEAP release induced by LPS. IκB-α degradation and nuclear translocation of NF-κB p50 subunit induced by LPS were significantly reduced by CORM-401. Additionally, CORM-401 significantly attenuated DNA-binding of p65 and p50 induced by LPS. CORM-401 attenuated NO generation induced by P. intermedia LPS independently of PPAR-γ, JNK, p38 and STAT1/3. Conclusion The modulation of host inflammatory response by CORM-401 might be of help in the therapy of periodontal disease.

Anti-inflammatory effects of hydrophobic constituents in the extract of the root cortex of Paeonia suffruticosa

Background: The root cortex of Paeonia suffruticosa Andrews (Paeoniaceae), which is also called moutan bark, is known as Botanpi in Japan. This crude drug has been used in several Kampo formulas, such as Daiobotanpito, to treat menstrual disturbance and constipation by improving blood stasis and suppressing inflammation. However, the anti-inflammatory effect has not been well studied.Objective: To clarify the anti-inflammatory effects of moutan bark, we isolated its constituents and investigated their activity.Methods: Moutan bark was extracted and successively fractionated with ethyl acetate (EtOAc) and n-butanol. The constituents were analyzed using HPLC. The production of nitric oxide (NO), an inflammatory mediator, was measured in interleukin (IL)-1β-treated rat hepatocytes to identify active fractions or constituents.Results: The EtOAc-soluble fraction of moutan bark extract significantly inhibited NO production. Three hydrophobic constituents were isolated from this fraction and identified as paeonol (1), 1,2,3,4,6-pentagalloyl-β-D-glucose (β-PGG; 2), and methyl gallate (3). Paeonol and paeoniflorin (4) were abundantly present in the EtOAc-soluble fraction and n-butanol-soluble fraction, respectively. The hydrophobic constituents suppressed NO production without exerting cytotoxicity and reduced the protein and mRNA levels of inducible nitric oxide synthase in IL-1β-treated hepatocytes; β-PGG showed the highest potency. Furthermore, β-PGG, methyl gallate, and paeonol decreased the mRNA levels of tumor necrosis factor α and IL-1 receptor type 1, which are involved in inflammation.Conclusion: These results suggest that hydrophobic constituents of moutan bark, such as β-PGG, methyl gallate, and paeonol, are involved in the anti-inflammatory effects of moutan bark.Keywords: Galloylglucose, tannin, nitric oxide, Kampo medicine, cytokine.

Murine macrophages do not support the proliferation of Leishmania (Viannia) braziliensis amastigotes even in absence of nitric oxide and presence of high arginase activity.

Leishmania (Viannia) braziliensis is the main species responsible for American tegumentary leishmaniasis in Brazil. Nevertheless, the use of this parasite species to study Leishmania infection in the murine model has been less conducted when compared with other Leishmania species. The control of murine infection with Leishmania has been associated with nitric oxide (NO) produced by inducible NO synthase (iNOS) from M1 macrophages, while arginase expressed by M2 macrophages is related to Leishmania proliferation. Here we use three different strains of L. (V.) braziliensis and one strain of L. (L.) major to study a 9-day infection of macrophages in vitro. Wild-type bone marrow-derived macrophages (BMDM) supported the proliferation of L. (L) major amastigotes from the 3rd day after infection, while all strains of L. (V.) braziliensis did not proliferate even inside IL-4-treated or iNOS knockout (KO) macrophages. The arginase activity was higher in iNOS KO than IL-4-treated macrophage showing that the absence of proliferation is independent of arginase. Importantly, L. (V.) braziliensis was able to cause uncontrolled disease in iNOS KO mice in vivo demonstrating that murine macrophages present at the site of infection have additional changes beyond inhibition of NO production or stimulation of arginase activity to support parasite proliferation.

Nitrooleic acid inhibits macrophage activation induced by lipopolysaccharide from Prevotella intermedia

The hypothesis of the present study was that nitro-fatty acids (NO2-FAs) would suppress inflammation associated with periodontal disease. To test this hypothesis, we investigated the influence of nitrooleic acid, a prototypical NO2-FA, on the inflammatory response of murine macrophages activated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen associated the etiology of different types of periodontal diseases. LPS was prepared from P. intermedia cells by using phenol-water protocol. Culture supernatants were assayed for nitric oxide (NO), interleukin-1β (IL-1β), and IL-6. Real-time polymerase chain reaction and immunoblotting analyses were performed to quantify messenger RNA and protein expression, respectively. The secreted embryonic alkaline phosphatase reporter assay was performed to measure NF-κB activation. The transcription factor assay kit was used to measure DNA-binding of NF-κB subunits. Findings obtained from the present study revealed that nitrooleic acid suppresses the generation and messenger RNA expression of inducible NO synthase-derived NO, IL-1β, and IL-6 in RAW264.7 cells activated with P. intermedia LPS and promotes macrophage polarization toward anti-inflammatory M2 phenotype. We also found that nitrooleic acid exerts its effect via heme oxygenase-1 induction and suppression of NF-κB signaling. The inhibition of NO and proinflammatory cytokine production by nitrooleic acid was independent from PPAR-γ, JNK, p38, and STAT1/3. Nitrooleic acid may represent a novel class of agent as a host modulator which has therapeutic benefit in periodontal disease, though more work is needed to confirm this.

Chemical Constituents from the Aerial Parts of Artemisia iwayomogi and Their Anti-Neuroinflammatory Activities.

Neuroinflammation, predominantly mediated by microglial activation, is a key immunological response in the pathogenesis of neurodegenerative disorders. In our preliminary study, the aerial part of Artemisia iwayomogi inhibits LPS-induced microglial activation. The present study aims to identify chemical constituents with anti-neuroinflammatory properties in the aerial parts of A. iwayomogi. Two new guaianolide sesquiterpenes, iwayomogins A and B (1 and 2), along with thirteen known sesquiterpene lactones (3–15), one diterpene glycoside (16), and nine phenolic compounds (17–25) were isolated from the aerial parts of A. iwayomogi by repeated chromatography. The structures of the isolates were elucidated by their spectroscopic data. All isolates were evaluated for their inhibitory activities on nitric oxide (NO) production in LPS-induced BV-2 microglial cells. 2,3-Dehydro-1-epi-asperilin (11) exhibited the strongest inhibitory effect on NO production (IC50 value of 1.78 μM). In the molecular docking study, three compounds (1, 2, and 11) showed good binding affinities with iNOS. Additionally, compounds 1, 2, and 11 inhibit pro-inflammatory cytokines (TNF-α and IL-6) in dose-dependent manners. The present study demonstrates that the chemical constituents from A. iwayomogi inhibit NO production and pro-inflammatory cytokine release in BV-2 cells. However, further evaluation with biological experiments utilizing in vivo models is necessary.

Methamphetamine-Induced Alterations of Vaginal Blood Flow in Rats

ABSTRACT Introduction Those suffering with vaginal dryness, whether experienced once or chronically, frequently experience painful and unpleasurable sexual experiences and diminished self-esteem as a result. Although the physiology of vaginal transudate production is long established, no pharmacological treatment other than estrogen has shown promise in attenuating vaginal dryness. Previously, our lab has shown that methamphetamine (meth) induced vaginal lubrication in adult women and anesthetized rats. The production of these vaginal secretions was shown to be dose-, as well as nitric oxide-dependent. As the secretion of vaginal lubrication is immensely dependent on local hemodynamics and the resulting increased blood flow to the genital tissues, determining meth-induced alterations in blood flow to these tissues is paramount. Objective The purpose of the current study is to determine if increased vaginal blood flow correlates with increased vaginal lubrication in response to meth, and to determine if alterations in this blood flow are nitric oxide-dependent. Methods Adult female Wistar rats were implanted with chronic indwelling jugular catheters and allowed at least one week to recover from surgery. Rats anesthetized with isoflurane gas were intravenously infused with meth (0.06-0.96 mg/kg) or saline via the implanted catheter. Vaginal blood flow, measured using a Periflux System 5000 and a small laser probe inserted 5-10 mm into the vaginal canal, was continuously recorded before and for at least twenty minutes following drug administration. After establishing meth-induced alterations in vaginal blood flow, pre-treatment with L-NG-Nitro arginine methyl ester (L-NAME), a non-specific nitric oxide synthase inhibitor, followed by meth administration following the same procedure for measuring blood flow allowed us to determine the contribution of nitric oxide to the observed changes in blood flow. Results Preliminary findings show that an IV infusion of meth induces an immediate increase in vaginal blood flow, followed by decreased blood flow due to vasoconstriction via increased sympathetic tone. We anticipate inhibition of nitric oxide production will reduce the increase in blood flow immediately after meth administration since this decreased vaginal lubrication in response to the same treatment. Conclusions These findings provide insight into the meth-induced vaginal lubrication we have previously reported, and that meth, whose sympathomimetic action traditionally induces vasoconstriction, produces increased blood flow in vaginal tissues, which is likely the driving force for the increased transudate produced. This advancement is critical for uncovering a mechanism that may serve as the optimal pharmacological target to treat vaginal dryness. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Embera NeuroTherapeutics & JanOne

Optic nerve head astrocytes contribute to vascular associated effects.

PurposeThis study was conducted in order to test the expression of vasoactive substances within rat lamina cribrosa (LC) and optic nerve head (ONH) astrocytes, so as to investigate the role and potential mechanism of ONH astrocytes in vascular associated effects.MethodsLC tissue sections and primary cultured ONH astrocytes were obtained from adult Sprague-Dawley (SD) rats. Immunofluorescent staining was then used to detect the expression of vasoactive substances. Hyperoxia exposure was carried out both in vivo and in vitro, after which nitric oxide (NO) levels in LC tissue and cell supernatant were detected. The variations of protein and gene expression associated with vasoactive substances were subsequently tested. ONH astrocytes and vascular smooth muscle cells (VSMCs) were then incubated in a direct co-culture manner. Morphological parameters of VSMCs were finally analyzed in order to evaluate cell contraction.ResultsEndothelin-1 (ET-1), nitric oxide synthase (NOS) and renin-angiotensin system (RAS) were detected in both LC tissue and ONH astrocytes. Retinal vessel diameter was found obviously decreased following hyperoxia exposure. Moreover, hyperoxia inhibited NO production both in vivo and in vitro. ET-1 and RAS elements were observed to be upregulated, whereas NOS was downregulated. In ONH astrocytes and VSMCs co-culture system, the length-to-width ratio of VSMCs was shown to significantly increase on days 3 and 7 in hyperoxia compared with normoxia.ConclusionsThere is an abundance of expression of vasoactive substances within LC tissue and ONH astrocytes. The contractile response of VSMCs in the co-culture system provided direct evidence for the involvement of ONH astrocytes in vascular associated effects, which may signify a potentially novel direction for future research.

Anti-inflammatory flavonoid derivatives from the heartwood of Dalbergia odorifera T. Chen

Two pairs of flavonoid enantiomers (1a/1b and 2a/2b) together with three known analogues (3–5) were isolated from the heartwood of Dalbergia odorifera T. Chen. Their structures were elucidated by extensive spectroscopic analysis (1 D and 2 D NMR, UV, IR, and HRMS) and experimental and calculated ECD data. Compound 2 features an unusual 2-methyl-3(2H)-furanone moiety forming the C-ring of flavonoid, and its putative biosynthetic pathway is also proposed. Compounds 3‒5 exhibited significant inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells with IC50 values of 14.7 ± 0.3 μM, 40.2 ± 1.1 μM, and 3.2 ± 0.1 μM, respectively.

Bifidobacterium lactis Inhibits iNOS Expression in LPS-stimulated RAW 264.7 Macrophages

BACKGROUND: Bifidobacterium is a genus of lactic acid bacteria that lives in the large intestine of humans and animals. The health benefits of this genus are well established; however, the anti-inflammatory activity of this genus, specifically Bifidobacterium lactis, has not been well defined. Therefore, in this study, we evaluated anti-inflammatory activity of B. lactis hydrolysates using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages.METHODS: RAW 264.7 cells were cultured using Dulbecco’s Modified Eagle’s Medium in 5 % CO2 incubator at 37 ℃. One µg/mL of LPS was used to stimulate RAW 264.7 cells. Nitric oxide (NO) production, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were measured to evaluate anti-inflammatory activity of B. lactis hydrolysates. The cytotoxicity of the inhibitor was also measured in present study through 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay.RESULTS: The results showed that B. lactis hydrolysates at 25–200 μg/mL inhibited NO production. In concentration-dependent manner, B. lactis hydrolysate showed inhibition of iNOS expression. However, no inhibition on COX-2 expression was observed. The MTS assay of the B. lactis hydrolysates showed no side effects on the cell viability at all concentrations.CONCLUSION: The current study revealed that B. lactis hydrolysates possess specific anti-inflammatory effects by inhibiting iNOS expression without cytotoxicity and therefore could potentially be developed as a new iNOS inhibitor.KEYWORDS: Bifidobacterium lactis, macrophages, hydrolysates, iNOS, COX-2

Anti-inflammatory effects of anthraquinones of Polygonum multiflorum roots

Background: The roots of Polygonum multiflorum Thunberg (Polygonaceae) are a crude drug known as Kashu and are thought to improve blood deficiency as a Kampo concept. Kashu is added to Kampo formulas, including Tokiinshi, which is used to treat eczema and dermatitis with itchiness by facilitating blood circulation in the skin. Although anti- inflammatory effects were expected, the reports on anti-inflammatory constituents of Polygonum roots are very few. Objective: To purify pharmacologically active constituents from Polygonum roots and compare their anti- inflammatory potency using hepatocytes. Methods: Polygonum roots were extracted and fractionated based on hydrophobicity to three fractions, the ethyl acetate (EtOAc)-soluble, n-butanol-soluble, and water-soluble fractions. Constituents were purified from the EtOAc- soluble fraction, and its contents were measured using liquid chromatography-triple quadrupole mass spectrometer. The interleukin (IL)-1β-induced production of nitric oxide (NO), a proinflammatory mediator, in rat hepatocytes was monitored to assess anti-inflammatory activity. Results: The EtOAc-soluble fraction inhibited IL-1β-induced NO production, whereas the other fractions did not. Six constituents were isolated from the EtOAc-soluble fraction and identified as (E)-2,3,5,4'-tetrahydroxystilbene-2-O-β- D-glucoside, emodin, emodin-8-O-β-D-glucopyranoside, physcion, physcion-8-O-β-D-glucopyranoside, and catechin. Emodin and emodin-8-O-β-D-glucopyranoside significantly inhibited NO production in hepatocytes, and the others showed less potency in suppressing NO production. These two anthraquinones decreased the protein and mRNA levels of inducible NO synthase, as well as the mRNA levels of tumor necrosis factor α. In a search of the literature to date, the comparison of pharmacological activity of the constituents of Polygonum roots was not reported.Conclusion: These results suggest that hydrophobic constituents in the EtOAc-soluble fraction, especially anthraquinones, may exert the anti-inflammatory effects by treatment with Polygonum roots.Keywords: anthraquinone, nitric oxide, inflammation, Kampo medicine, LC–MS/MS.

Adenostemmoic acid B suppresses NO production by downregulating the expression and inhibiting the enzymatic activity of iNOS

Adenostemmoic acid B (AB) is a major compound found in Adenostemma lavenia ; it shows anti-melanogenic, anti-inflammatory, and cytotoxic activities. By modifying the 19th position (carboxy: involved in the avoidance of cytotoxicity) of AB, we succeed to separate these activities. Short-chain alkylation of the carboxy group enhanced anti-melanogenic activity, while long-chain alkylation (hydrophobic) resulted in the suppression of nitric oxide (NO) production and inducible NO synthase (iNOS) expression without anti-melanogenic activity. Re-modification of hydrophilic properties in these long-chain derivatives restored anti-melanogenic activity but did not suppress NO production. Unexpectedly, AB and derivatives with long chains linked by an anhydride bond were new iNOS inhibitors. These results suggest that AB modulates multiple physiological activities by regulating different targets, including iNOS. • Adenostemmoic acid B is a multipotential ingredient in Adenostemma lavenia. • Adenostemmoic acid B suppresses gene expression of tyrosinase (anti-melanogenesis) and iNOS (anti-inflammatory). • Adenostemmoic acid B and its derivatives with an anhydride bond inhibit iNOS enzyme activity.

Six new tigliane diterpenoids with anti-inflammatory activity from Euphorbia kansuensis

Six new tigliane diterpenoids, euphkanoids A − F (1–6), along with 12 known diterpenoids (7–18) were isolated from the roots of Euphorbia kansuensis, a traditional Chinese medicinal plant. Their structures were elucidated by spectroscopic analysis, ECD calculation and chemical methods. Compounds 1–3 represent the unusual examples of tigliane diterpenoids with a conjugated olefinic aldehyde moiety. 1–18 and two hydrolyzed analogues (1c and 4a) were screened for the inhibitory effects on nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 cells. The results showed that 1–3 and 6 markedly inhibited NO production with IC50 values in the range of 4.8–11.3 μM, which were more active than the positive control quercetin (IC50 = 12.3 μM).

Labdanum Resin from Cistus ladanifer L.: A Natural and Sustainable Ingredient for Skin Care Cosmetics with Relevant Cosmeceutical Bioactivities.

Labdanum resin from Cistus ladanifer L. (Cistaceae) is an abundant natural resource in the Iberian Peninsula worth being explored in a sustainable manner. It is already used in the cosmetic industry; mainly by the fragrances/perfumery sector. However, given the highest market share and traditional uses, labdanum resin also has the potential to be used and valued as a cosmetic ingredient for skincare. Aiming to evaluate this potential, labdanum methanolic absolute and fractions purified by column chromatography were characterized by UPLC-DAD-ESI-MS and then evaluated for UV-protection, antioxidant, anti-elastase, anti-inflammatory, and antimicrobial activities. Labdanum absolute represented ~70% of the resin; diterpenoid and flavonoid fractions represented ~75% and 15% of the absolute, respectively. Labdane-type diterpenoids and methylated flavonoids were the main compounds in labdanum absolute and in diterpenoid and flavonoid fractions, respectively. Labdanum absolute showed a spectrophotometric sun protection factor (SPF) near 5, which is mainly due to flavonoids, as the flavonoids’ SPF was 13. Low antioxidant activity was observed, with ABTS radical scavenging being the most significant (0.142 ± 0.017, 0.379 ± 0.039 and 0.010 ± 0.003 mgTE/mgExt, for the absolute and flavonoid and terpene fractions, respectively). Anti-aging and anti-inflammatory activity are reported here for the first time, by the inhibition of elastase activity (22% and 13%, by absolute and flavonoid extract at 1 mg/mL), and by the inhibition of nitric oxide production in LPS-induced RAW 264.7 cells (84% to 98%, at 15 µg/mL extracts, flavonoid fraction the most active), respectively. Antimicrobial activity, against relevant skin and cosmetic product microorganisms, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Escherichia coli, revealed that only S. aureus was susceptible to labdanum absolute (MIC: 1.2 mg/mL) and its fractions (MIC: <0.3 mg/mL). In conclusion, labdanum resin showed potential to be used in sunscreen cosmetics, anti-inflammatory skincare cosmeceuticals or medicines but has low potential as a cosmetic product preservative given the low antioxidant and low-spectrum antimicrobial activities.

Two new stilbenoid diglycosides from the stems of Dendrobium ‘Sonia’

Two undescribed stilbenoid diglycosides, dendrosonside A and dendrosonside B (1 and 2), were isolated from the stems of Dendrobium ‘Sonia’. Their structures were elucidated based on 1 D/2D NMR and HRESIMS. The glycosyls contained in the two isolates were determined as D-glucose by acid hydrolysis and GC-MS analyses. In addition, 1 and 2 were further tested for the inhibition of nitric oxide production.

Amelioration of TPA-induced skin inflammation by the leaf extract of Vernonia amygdalina involves ERK/STAT3 (Ser727) signaling inhibition

BackgroundUncontrolled inflammation causes health problems. Extracellular signal-regulated kinase (ERK) phosphorylates signal transducer and activator of transcription 3 (STAT3) at Ser727, resulting in inflammation. The leaf of Vernonia amygdalina (VA) is a medicinal herb for managing inflammation-associated diseases. Oral administration or topical application of VA leaf extract exerts anti-inflammatory effects in rat models. However, the anti-inflammatory mechanisms of the herb are not fully understood. PurposeIn this study, we aimed to investigate the involvement of ERK/STAT3 (Ser727) signaling in the anti-inflammatory effects of an ethanolic extract of VA leaves. Study design and methodsExtracts of VA leaves were prepared with different concentrations of ethanol. A LPS-stimulated RAW264.7 cell model was used for in vitro assays, and a TPA (12-O-tetradecanoylphorbol-13-acetate)-induced ear edema mouse model was employed for in vivo assays. The 95% ethanol extract of VA leaves (VAE) exerted the strongest inhibitory effect on nitric oxide (NO) production in LPS-stimulated macrophages; thus it was selected for use in this study. Hematoxylin and eosin (H&E) staining was used to examine pathological conditions of mouse ear tissues. Griess reagent was employed to examine NO generation in cell cultures. Immunoblotting and ELISA were used to examine protein levels, and RT-qPCR was employed to examine mRNA levels. ResultsTopical application of VAE ameliorated mouse ear edema induced by TPA. VAE suppressed the phosphorylation of ERK (Thr202/Tyr204) and STAT3 (Ser727); and decreased protein levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin (IL)-6, IL-1β and tumor necrosis factor-α (TNF-α) in the mouse ear tissues and in LPS-stimulated RAW 264.7 cells. VAE also inhibited NO production, and lowered mRNA levels of IL-6, IL-1β and TNF-α in the macrophages. ConclusionsVAE ameliorates TPA-induced mouse ear edema. Suppression of ERK/STAT3 (Ser727) signaling is involved in VAE's anti-inflammatory effects. These novel data provide further pharmacological justifications for the medicinal use of VA in treating inflammation-associated diseases, and lay the groundwork for developing VAE into a new anti-inflammatory agent.

On the kinetic mechanism of dimethylarginine dimethylaminohydrolase

Dimethylarginine dimethylaminohydrolase (DDAH, EC 3.5.3.18) catalyzes the hydrolysis of asymmetric Nω,Nω-dimethyl-l-arginine (ADMA), an endogenous inhibitor of human nitric oxide synthases. The active-site cysteine residue has been proposed to serve as the catalytic nucleophile, forming an S-alkylthiourea reaction intermediate, and serving as a target for covalent inhibitors. Inhibition can lead to ADMA accumulation and downstream inhibition of nitric oxide production. Prior studies have provided experimental evidence for formation of this covalent adduct but have not characterized it kinetically. Here, rapid quench-flow is used with ADMA and the DDAH from Pseudomonas aeruginosa to determine the rate constants for formation (k2 = 17 ± 2 s−1) and decay (k3 = 1.5 ± 0.1 s−1) of the covalent S-alkylthiourea adduct. A minimal kinetic mechanism for DDAH is proposed that supports the kinetic competence of this species as a covalent reaction intermediate and assigns the rate-limiting step in substrate turnover as hydrolysis of this intermediate. This work helps elucidate the different reactivities of S-alkylthiourea intermediates found among the mechanistically diverse pentein superfamily of guanidine-modifying enzymes and provides information useful for inhibitor development.

Synthesis and Antioxidant/Anti-Inflammatory Activity of 3-Arylphthalides.

Phthalides are a group of compounds with relevant biological activities in different areas such as cytotoxicity, anti-stroke activity, neuroprotection, and inflammation, among others. In this study we designed and synthesized a series of 3-arylphthalide derivatives in order to identify their antioxidant and anti-inflammatory activities. The synthetic methodology was established in terms of atom and step economy through a dehydrative coupling reaction between 3-hydroxyphthalide and different properly functionalized arene rings. The evaluation of the antioxidant activity was performed by the ABTS assay and for the anti-inflammatory activity the inhibition of LPS-induced nitric oxide (NO) production in microglial cells Bv.2 and macrophage cells RAW 264.7 was measured. The synthesized compound 3-(2,4-dihydroxyphenyl)phthalide (5a) showed better antioxidant activity than the Trolox standard and caused strong inhibition of NO production in LPS-stimulated Bv.2 and RAW 264.7 cells. In addition, compound 5a reduced the expression of the pro-inflammatory cytokines Il1b and Il6 in RAW 264.7 cells. These results, which are the first account of the anti-inflammatory activity of 3-arylphthalides, suggest that compound 5a could be a promising candidate for more advanced anti-inflammatory studies.