Inhibition Of NO Production Research Articles

Discovery of a 4-Hydroxy-3'-Trifluoromethoxy-Substituted Resveratrol Derivative as an Anti-Aging Agent.

With the intensification of population aging, aging-related diseases are attracting more and more attention, thus, the study of aging mechanisms and anti-aging drugs is becoming increasingly urgent. Resveratrol is a potential candidate as an anti-aging agent, but its low bioavailability limits its application in vivo. In this work, a 4-hydroxy-3'-trifluoromethoxy-substituted resveratrol derivative (4-6), owing to its superior cell accumulation, could inhibit NO production in an inflammatory cell model, inhibit oxidative cytotoxicity, and reduce ROS accumulation and the population of apoptotic cells in an oxidative stress cell model. In D-galactose (D-gal)-stimulated aging mice, 4-6 could reverse liver and kidney damage; protect the serum, brain, and liver against oxidative stress; and increase the body's immunity in the spleen. Further D-gal-induced brain aging studies showed that 4-6 could improve the pathological changes in the hippocampus and the dysfunction of the cholinergic system. Moreover, protein expression related to aging, oxidative stress, and apoptosis in the brain tissue homogenate measured via Western blotting also showed that 4-6 could ameliorate brain aging by protecting against oxidative stress and reducing apoptosis. This work revealed that meta-trifluoromethoxy substituted 4-6 deserved to be further investigated as an effective anti-aging candidate drug.

The chemical profiling and identification of Abelia macrotera (Graebn. et Buchw.) Rehd. based on UHPLC-Q-Exactive Orbitrap MS and study their antioxidant, anti-tyrosinase and anti-inflammatory activities

Although Abelia macrotera has long been used as the raw material for the special snack “immortal tofu” by Chinese population, the composition and activity of its leaf and stem are rarely studied. Ultrahigh-performance liquid chromatography-quadrupole (UHPLC-Q)-Exactive Orbitrap mass spectrometry and various experiments were used for in vitro study of its chemical composition and antioxidant, antityrosinase, and anti-inflammatory activities. A fast, accurate, and sensitive UHPLC-Q-Exactive Orbitrap mass spectrometry method has been established and effectively used for the determination of the chemical composition of the leaf and stem of A. macrotera. The biological activities of the leaf and stem extracts of the A. macrotera were determined in vitro by antioxidant and anti-inflammatory methods. A total of 142 chemical constituents including 48 flavonoids, 65 organic acids, 12 phenylpropanoids, and 19 others were identified by UHPLC-Q-Exactive Orbitrap mass spectrometry. The results show that the leaf and stem extracts have wide and significant antioxidant capacities, including scavenging effects of DPPH, ABTS and hydroxyl radicals, and the ability to reduce both iron and copper metal ions. Additionally, they showed a strong inhibition of NO production, with a dose-dependent inhibition. To the best of our knowledge, this is the first study to report the identification and content determination of the chemical components of the A. macrotera leaf and stem. These results will be beneficial to further understand its medicinal value.

Endothelial lipid droplets suppress eNOS to link high fat consumption to blood pressure elevation.

Metabolic syndrome, today affecting more than 20% of the US population, is a group of 5 conditions that often coexist and that strongly predispose to cardiovascular disease. How these conditions are linked mechanistically remains unclear, especially two of these: obesity and elevated blood pressure. Here, we show that high fat consumption in mice leads to the accumulation of lipid droplets in endothelial cells throughout the organism and that lipid droplet accumulation in endothelium suppresses endothelial nitric oxide synthase (eNOS), reduces NO production, elevates blood pressure, and accelerates atherosclerosis. Mechanistically, the accumulation of lipid droplets destabilizes eNOS mRNA and activates an endothelial inflammatory signaling cascade that suppresses eNOS and NO production. Pharmacological prevention of lipid droplet formation reverses the suppression of NO production in cell culture and in vivo and blunts blood pressure elevation in response to a high-fat diet. These results highlight lipid droplets as a critical and unappreciated component of endothelial cell biology, explain how lipids increase blood pressure acutely, and provide a mechanistic account for the epidemiological link between obesity and elevated blood pressure.

Four Steroidal Saponins from the Trunks of Dracaena cambodiana with Inhibition of NO Production in LPS Activated RAW264.7 Cells.

Dracaena cambodiana Pierre ex Gagnep. is well known as a medicinal plant and widely distributed in Vietnam. Phytochemical investigation on the trunks of D. cambodiana lead to the isolation of four undescribed compounds (1-4) together with seven known ones (5-11). Their structures were determined to be pennogenin-24-yl-O-β-D-glucopyranoside (1), 17α-hydroxycambodianoside C (2), (25R)-27-hydroxypenogenin 3-O-α-L-rhamnopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside (3), (3β,25R)-17α,22α-dihydroxy-furost-5-en-3-yl-O-α-L-rhamnopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-β-D-glucopyranoside (4), dracagenin A (5), 1-O-β-D-glucopyranosyl-2-hydroxy-4-allylbenzene (6), 1-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl-2-hydroxy-allylbenzene (7), 2-O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranosyl-1-hydroxy-allylbenzene (8), cinnamrutinoside A (9), icariside D1 (10), and seco-isolariciresinol 9-O-β-glucopyranoside (11) by extensive spectroscopic investigation, HR-ESI-MS, 1D and 2D NMR spectra. The anti-inflammatory activity of the isolated compounds was evaluated on macrophages. Compounds 1-6 significantly inhibited nitric oxide production in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Among them, compound 1 showed the best inhibitory activity with an IC50 value of 8.90±0.56 μM.

Minor protopanaxadiol type sapogenins from the alkali hydrolysate of stems-leaves of Panax notoginseng

Two new protopanaxadiol type sapogenins, (3β,12β)-3,12,20-trihydroxydammar-24-en-26-al (1) and (3β,12β)-3,12,20-trihydroxydammar-24-en-26-oic acid (2), were isolated from the alkali hydrolysate of stems-leaves of Panax notoginseng, along with seven known analogues (3–9). Their structures were elucidated by spectroscopic analyses and single-crystal X-ray diffraction. Compound 2 and the known sapogenins 5–8 displayed weak to moderate inhibition of NO production in LPS-induced RAW264.7 macrophages with IC50 values from 44.5 to 143.6 μM, respectively.

Effects of laminarin on growth performance and resistance against Pseudomonas plecoglossicida of large yellow croaker （Larimichthys crocea）

Laminarin (LAM) is widely used as an immunopotentiator in aquaculture, but its protective mechanism is still unclear. In this study, the effects of LAM on the growth performance and resistance against Pseudomonas plecoglossicida of large yellow croaker were studied in vitro and in vivo. The 42 d-feeding trial in large yellow croaker showed that dietary LAM could obviously promote the fish growth by improving the weight gain rate (WGR), specific growth rate (SGR), and feed conversion rate (FCR). Dietary LAM could also improve the survival rate of large yellow croakers subjected to P. plecoglossicida infection, and 500 mg/kg LAM produced the highest relative percent survival (RPS) of 35.00 %. LAM improved fish antioxidant level by enhancing serum total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity, and reducing malondialdehyde (MDA) content. In addition, LAM also improved fish innate immunity by increasing serum acid phosphatase (ACP) and alkaline phosphatase (AKP) activities and complement 3 (C3) content under P. plecoglossicida infection. What is more, on 9 d post P. plecoglossicida challenge, LAM could significantly decrease the bacteria load in head kidneys, spleens and livers of fish, and the lowest bacterial load was found in 500 mg/kg LAM group. In vitro, LAM exerted a protective role against inactivated P. plecoglossicida-triggered inflammatory injury in primary head kidney macrophages (PKM) of large yellow croaker by recovering cell viability, suppressing NO production, and reversing pro-inflammatory cytokine expression (IL-1β, IL-6, and IL-8). All these findings therefore will provide insights into the protection mechanism of LAM in fish, facilitating its application in prevention and control of fish bacteriosis.

Structures and bioactivities of monomeric and dimeric carvotacetones from Sphaeranthus africanus

Four previously undescribed carvotacetones including one monomeric (1) and three dimeric (8, 9, 10) derivatives, together with six known compounds were isolated from the n-hexane extract of the aerial parts of Sphaeranthus africanus L. The structures of the previously undescribed compounds were elucidated as 3-angeloyloxy-5-isobutanoyloxy-7-hydroxycarvotacetone (1), 7,7′-oxybis{3-angeloyloxy-5-[(2R*,3R*)-2,3-dihydroxy-2-methylbutanoyloxy]carvotacetone} (8), (2″S*,3″R*)-7-{3-angeloyloxy-5-[(2R*,3R*)-2,3-dihydroxy-2-methylbuta-noyloxy]carvotaceton-7-yloxy}-3-angeloyloxy-5-(2,3-dihydroxy-2-methylbutanoyloxy)carvo-tacetone (9), and 7,7′-oxybis{3-angeloyloxy-5-[(2S*,3R*)-2,3-dihydroxy-2-methylbutanoyl-oxy]carvotacetone} (10). The three dimeric derivatives (8–10) showed potent anti-proliferative activity against human cancer cell lines (CCRF-CEM, MDA-MB-231, U-251, HCT-116) with IC50 values ranging from 0.2 to 2.0 μM. Caspases 3 and 7 were found to be activated by all compounds, indicating apoptosis induction activity. Monomers exhibited a specific inhibition of NO production in BV2 and RAW 264.7 cells with IC50 values ranging from 4.2 to 6.8 μM which were 2–3.5-fold lower than IC50 values causing cytotoxicity. In addition, the carvotacetones reduced NF-κB1 (p105) mRNA expression at concentrations of 10 and 2.5 μM. Altogether, the results indicate that carvotacetones may be interesting lead structures for the development of anti-cancer and anti-inflammatory drugs.

Carabrachiatanins A and B: Two New Phenylpropanoid-Substituted Catechins of Carallia brachiata Merr

Objectives: Carallia brachiata Merr. is a Vietnamese medicinal plant, used to treat mouth ulcers, tongue sores, sore throats, and malaria. This paper focuses on the chemical constituents of C. brachiata and their inhibition of NO production. Methods: The dried and minced sample was extracted with methanol. The crude extract was isolated by various chromatographic methods. The structures of the isolates were determined by HR-ESI-MS, NMR, and CD spectra. The NO inhibition activity was evaluated in LPS-activated RAW264.7 cells. Results: Two new catechin derivatives (carabrachiatanins A (1) and B (2)) and seven known proanthocyanidins (3-9) were isolated from C. brachiata by bioguided fractionation. All isolates significantly showed NO inhibition effects with IC50 values ranging from 13.72 ∼ 34.28 µM. Conclusions: Two new and seven known compounds were isolated from C. brachiata. This is the first report of compounds 3-9 from C. brachiata. Compounds 7 and 8 inhibited NO production with their IC50 values of 16.31 ± 0.61 µM and 16.53 ± 0.83 µM, respectively, compared to that of dexamethasone, which showed IC50 value of 14.94 ± 1.11 µM.

Four New Pentacyclic Triterpene Glycosides Isolated from the Fruits of Cryptolepis buchananii R.Br. ex Roem. & Schult and Their Inhibition of NO Production in LPS-activated RAW264.7 Cells.

From the methanol extract of the Cryptolepis buchananii fruits, four undescribed pentacyclic triterpenene glycosides (1-4) and five known pentacyclic triterpenenes (5-9) were isolated. Their structures were determined to be uncargenin C 28-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl ester (1), 3-O-β-D-glucopyranosyluncargenin C 28-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl ester (2), 3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl-6β,23-dihydroxyursolic acid 28-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl ester (3), 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosylasiatic acid 28-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl ester (4), asiatic acid (5), 2α,3β,23-trihydroxyoleana-11,13(18)-dien-28-oic acid (6), arjunolic acid (7), 6β-hydroxyarjunolic acid (8), and actinidic acid (9) based on analyses of their HR-ESI-MS, 1D and 2D NMR spectra. All the isolates showed significantly NO production inhibition in LPS-activated RAW264.7 cells with the IC50 values ranging from 18.79 to 37.57 μM, compared to that of the positive control compound, dexamethasone, which showed IC50 value of 14.05 μM.

Terpenoids from the Roots of Stellera chamaejasme (L.) and Their Bioactivities

An undescribed diterpene, stellerterpenoid A (1), and two undescribed sesquiterpenoids, stellerterpenoids B and C (2–3), together with six known compounds, prostratin (4) stelleraguaianone B (5), chamaejasnoid A (6), auranticanol L (7), wikstronone C (8), and oleodaphnone (9), were isolated from the roots of Stellera chamaejasme L. Their structures were elucidated by extensive spectroscopic data (1D, 2D NMR, IR, UV, and HR-ESI-MS). The absolute configuration of 1–3 was elucidated based on ECD calculation. Among them, stellerterpenoid A was a rare 13, 14-seco nortigliane diterpenoid and stellerterpenoid B was a guaiacane-type sesquiterpenoid with an unusual 1, 2-diketone moiety. The known stelleraguaianone B (5) exhibited moderate activity for suppressing NO production in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages cells with an IC50 value of 24.76 ± 0.4 μM. None of the compounds showed anti-influenza virus or anti-tumor activity in vitro.

Meroterpenoids with divers' rings systems from Phyllosticta capitalensis and their anti-inflammatory activity

Four undescribed sesquiterpene-shikimates (1–4), eight undescribed monoterpene-shikimates (5–12), together with two known ones were isolated and identified from the 95% ethanol extract of the plant endophytic fungus Phyllosticta capitalensis cultured in rice medium. Capitalensis A (1) was identified as the first sesquiterpene-shikimate-conjugated spirocyclic meroterpenoid degradation product, while capitalensis B (2) is a sesquiterpene-shikimate-conjugated spirocyclic meroterpenoid with a unique D-ring formed by a C-2–O–C-9′ connection. The structures of these previously undescribed compounds were elucidated by multiple techniques, including IR, HR-ESI-MS, and NMR analysis. Furthermore, their absolute configurations were established through the comprehensive approach that involved the calculations of ECD spectra, optical rotation values, and single-crystal X-ray analysis. Moreover, the anti-inflammatory activity of all isolated compounds was evaluated using a lipopolysaccharide (LPS)-induced inflammation model in BV2 microglial cells. Meanwhile, these compounds exhibited activity in inhibiting NO production. Four compounds, capitalensis C (3), capitalensis D (4), 15-hydroxyl tricycloalternarene 5b (13) and guignarenone A (14) showed strong inhibitory effects with IC50 values of 21.6 ± 1.33, 12.2 ± 1.08, 18.6 ± 1.27, and 15.8 ± 1.20 μM, respectively. In addition, the structure-activity relationship of the anti-inflammatory activity of the compounds was discussed.

Identification of Major Bioactive Anti-inflammatory Compounds of Derris scandens Stem Using RAW 264.7 Cells and HPLC-UV Analysis.

Derris scandens (DS) is widely recognized for its therapeutic properties, specifically its analgesic effects, which significantly alleviate muscle pain. The chemical constituents of DS stem include various isoflavone derivatives. However, there is currently a lack of specified anti-inflammatory chemical markers and analytical methods for quality control. The present study aimed to evaluate the anti-inflammatory activity of DS and its constituents using the RAW 264.7 cell model. The expression of inflammatory genes such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), and 5-lipoxygenase (5-LOX) was examined using quantitative RT-PCR. An high-performance liquid chromatography with a UV detection method was developed to quantitatively analyze genistein-7-O-[α-rhamnopyranosyl-(1 → 6)]-β-glucopyranoside, genistein, derrisisoflavone A, lupalbigenin, and 6,8-diprenylgenistein in DS stem. The developed HPLC-UV method demonstrated high sensitivity with limits of detection and quantification ranging from 0.01 to 0.06 µg/mL and 0.03 to 0.18 µg/mL, respectively. The accuracy of the method ranged from 93.3 to 109.6%. Furthermore, the repeatability and reproducibility of the method were suitable, as indicated by the relative standard deviations of ≤ 3.02% and ≤ 6.22%, respectively. The DS extract notably inhibited NO production, exhibiting effects comparable to those of 500 µM diclofenac, and substantially suppressed the expression of iNOS, COX-2, IL-6, and 5-LOX of lipopolysaccharide (LPS)-induced genes. As to the pure isoflavone derivatives, the order of NO production inhibition was found to be genistein > lupalbigenin > derrisisoflavone A > 6,8-diprenylgenistein > genistein-7-O-[α-rhamnopyranosyl-(1 → 6)]-β-glucopyranoside. Genistein, derrisisoflavone A, and 6,8-diprenylgenistein significantly suppressed the upregulation of all LPS-induced genes. Consequently, these compounds are recommended as anti-inflammatory markers for the quantitative chemical analysis of DS.

Essential oils from Acronychia pedunculata (L.) Miq. in Vietnam: chemical composition, antimicrobial, cytotoxicity and nitric oxide inhibition activities

The chemical composition, antimicrobial, cytotoxic and anti-inflammatory activities of essential oils from different parts of Acronychia pedunculata, a medicinal plant native to Central Highlands of Vietnam, were investigated. Their chemical constituents were determined using GC-MS. The antimicrobial properties were assessed using a microdilution broth method, while the anti-inflammatory properties were measured based on their capacity to inhibit NO production in macrophage cells. Their cytotoxicity was tested using the sulforhodamine B assay on three human cancer cell lines. The GC-MS analysis revealed the presence mainly of caryophyllene oxide (35.3%) and spathulenol (31.9%) in the stem essential oil, caryophyllene oxide (51.3%), and linalool (21.0%) in the leaf essential oil, and α-pinene (21.4%), (E)-β-ocimene (16.5%), linalool (12.5%), and β-caryophyllene (13.0%) in the fruit essential oil. All three essential oils inhibited the growth of various bacteria and fungi, reduced NO production in LPS-induced RAW264.7 cells, and exhibited cytotoxicity against all three tested cancer cell lines. Notably, the fruit essential oil showed the most potent cytotoxicity among the essential oils, with IC50 values of 5.47 ± 0.21, 7.95 ± 0.35, and 9.22 ± 0.52 g/mL against SK-LU-1, MCF-7, and HepG2 cells, respectively. It also had a strong anti-inflammatory effect that was comparable to that of dexamethasone, with an IC50 value of NO production inhibition of 14.62 ± 0.62 mg/mL. These results suggest the potential of the essential oils from this plant to provide leads for the development of anti-inflammatory and anti-cancer agents.

Heat shock increases the anti-inflammatory and anti-obesity activity of soybean by increasing polyphenol, antioxidant and aglycon form isoflavones

We know that heat shock can activate the functional components in soybeans, but we don't know the type, level, and duration of heat shock for maximum activation. To address this, the present study investigated the changes in functional components like polyphenols, antioxidants, and isoflavones in soybeans at various temperature levels and durations with their respective functionality or health benefits. For this, treated seed samples were extracted with 70 % ethanol. Heat shock at 60 °C for 2 h increased polyphenol content (60.67 % of control) and antioxidant activity for both ABTS (41.14 % of control) and DPPH (217.72 % of control). This also increased the beneficial aglycone form of isoflavones that includes daidzein (8.36-fold of control), glycitein (3.85-fold of control) and genistein (20.50-fold of control) but decreased the harmful β-glucoside form (3.65-fold) including daiazin (1.84-fold of control); glycitin (1.45-fold of control) and genistin (23.88-fold of control) over untreated dry seed. This may happen because of the conversion of conjugated β-glucoside isoflavones to their aglycone forms that have various health benefits. Maximum inhibition of NO production in RAW 264.7 cells was achieved by samples elicited for 2 h with 300 μg/mL concentration. This sample also confirmed the maximum anti-obesity activity treated against 3-T-3L1 cells. This study summarized that heat shock at 60 °C for 2 h increased polyphenols, antioxidants, and aglycon isoflavone in soybeans resulting in increased anti-inflammatory and anti-obesity activity.

Synthesis, Characterization, and in vitro Anti-Inflammatory Activity of Novel Ferrocenyl(Piperazine-1-Yl)Methanone-based Derivatives.

Inflammation is closely related to the occurrence and development of various diseases in the clinical scope. Finding effective anti-inflammatory agents is of great significance for clinical treatment. A series of novel ferrocenyl(piperazine-1-yl)methanone-based sulfamides and carboxamides were synthesized to discover potent anti-inflammatory agents. The compounds were characterized by 1H NMR, 13C NMR, and MS spectra. Compound 5h was further determined by single crystal X-ray diffraction. All the target compounds were screened for anti-inflammatory activity by evaluating the inhibition effect of LPS-induced NO production in RAW264.7 macrophages. The novel compound (4i) is the preliminary anti-inflammatory mechanism detected by western blot. In a multi-stage screening campaign, compound 4i was shortlisted, which exhibited physicochemical properties suitable for human administration. Among them, compound 4i was found to be most potent in inhibiting NO production (IC50 = 7.65 μM) with low toxicity. This compound also exhibited significant inhibition of the production of iNOS and COX-2. Preliminary mechanism studies indicated that compound 4i could inhibit the activation of the LPS-induced TLR4/NF-κB signaling pathway. The promising anti-inflammatory activity of compound 4i compared with the reference drug suggests that this compound may contribute as a lead compound in the search for new potential anti-inflammatory agents.

Cooling-induced cutaneous vasodilatation is mediated by small-conductance, calcium-activated potassium channels in tail arteries from male mice.

Cooling causes cutaneous dilatation to restrain cold-induced constriction and prevent tissue injury. Cooling increases communication through myoendothelial gap junctions (MEGJs), thereby increasing endothelium-derived hyperpolarization (EDH)-type dilatation. EDH is initiated by calcium-activated potassium channels (KCa ) activated by endothelial stimuli or muscle-derived mediators traversing MEGJs (myoendothelial feedback). The goal of this study was to determine the individual roles of KCa with small (SK3) and intermediate (IK1) conductance in cooling-induced dilatation. Vasomotor responses of mice isolated cutaneous tail arteries were analyzed by pressure myography at 37°C and 28°C. Cooling increased acetylcholine-induced EDH-type dilatation during inhibition of NO and prostacyclin production. IK1 inhibition did not affect dilatations to acetylcholine, whereas SK3 inhibition inhibited dilatation at both temperatures. Cooling uncovered myoendothelial feedback to inhibit constrictions in U46619. IK1 inhibition did not affect U46619 constrictions, whereas SK3 inhibition abolished the inhibitory effect of cooling without affecting U46619 constriction at 37°C. Immunoblots confirmed SK3 expression, which was localized (immunofluorescence) to holes in the internal elastic lamina consistent with myoendothelial projections. Immunoblots and Immunofluorescence did not detect IK1. Studies in non-cutaneous arteries have highlighted the predominant role of IK1 in EDH-type dilatation. Cutaneous arteries are distinctly reliant on SK3, which may enable EDH-type dilation to be amplified by cooling.

Antioxidative and Anti-inflammatory Effects of Daehwangmokdanphee-tang

This study was conducted to investigate antioxidant and anti-inflammatory effects of Daehwangmokdanphee-tang (DHMDPT). The antioxidant activity was evaluated the total polyphenol contents and total flavonoid contents. Additionally we measured the ABTS radical scavenging activity, superoxide dismutase (SOD)-like activity and electron-donating ability with DHMDPT. In addition, inhibition of NO production in RAW 264.7 cells induced by LPS was evaluated to investigate the anti-inflammatory effect. The results of total polyphenol contents, total flavonoid contents was 52.87±12.52 mg/g and 7.20±4.49 mg/g in DHMDPT. Antioxidant activity results of DHMDPT through ABTS radical scavenging activity, superoxide dismutase (SOD)-like activity, and electron-donating ability are highly active in a dose-dependent showed high activity. The cell toxicity of DHMDPT was evaluated using the RAW 264.7 cells. LPS-induced inhibition of NO secretion was increased in DHMDPT in a dose-dependent manner. This result indicates that DHMDPT might have antioxidant and anti-inflammatory effects in vitro assay, and can be developed as a cosmetic material in the future.

Macroporous resin purification of phenolics from Irish apple pomace: Chemical characterization, and cellular antioxidant and anti-inflammatory activities

Apple pomace (AP) is a highly prevalent waste product worldwide in the fruit processing sector. This study compared the chemical profile, antioxidant, and anti-inflammatory activities of crude (CE) and an extract purified using XAD-7 resin (PE). The purification process increased the total phenolic content, flavonoids, and tannins by 3.35, 40.31, and 8.87-fold, respectively. The main phenolic compounds identified in PE were phlorizin (20.54 mg/g), chlorogenic acid (10.01 mg/g), and hyperoside (2.77 mg/g). No difference was found between CE and PE in protecting human plasma against oxidation. In human erythrocytes, both CE and PE decreased the reactive oxygen species (ROS) generation and decreased lipoperoxidation. However, PE had stronger anti-inflammatory effects than CE by promoting HO-1 gene expression, suppressing NO production, and inhibiting IL-1β, IL-6, and IL-10 mRNA expression in lipopolysaccharide-challenged RAW.264.7 macrophages. Therefore, purifying apple pomace crude extract is a promising approach to boosting valuable antioxidants and anti-inflammatory phenolics.

The PPE2 protein of Mycobacterium tuberculosis is secreted during infection and facilitates mycobacterial survival inside the host

Mycobacterium tuberculosis secrets various effector proteins to evade host immune responses for facilitating its intracellular survival. The bacterial genome encodes several unique PE/PPE family proteins, which have been implicated to play important role in mycobacterial pathogenesis. A member of this family, PPE2 have been shown to contain a monopartite nuclear localization signal (NLS) and a DNA binding domain. In this study, we demonstrate that PPE2 protein is present in the sera of mice infected with either M. smegmatis expressing PPE2 or a clinical strain of M. tuberculosis (CDC1551). It was found that exogenously added PPE2 can permeate through the macrophage cell membrane and eventually translocate into the nucleus which requires the presence of NLS which showed considerable homology to HIV-tat like cell permeable peptides. Exogenously added PPE2 could inhibit NO production and decreased mycobacterial survival in macrophages. PPE2-null mutant of M. tuberculosis failed to inhibit NO production and had poor survival in macrophages which could be rescued by complementation with full-length PPE2. PPE2-null mutants also had poor survival in the lungs of infected mice indicating that PPE2 even when present in the bloodstream can confer a survival advantage to mycobacteria.

The Muscarinic Acetylcholine M2 Receptor-Induced Nitration of p190A by eNOS Increases RhoA Activity in Cardiac Myocytes.

p190RhoGAP, which exists in two paralogs, p190RhoGAP-A (p190A) and p190RhoGAP-B (p190B), is a GTPase activating protein (GAP) contributing to the regulation of the cellular activity of RhoGTPases. Recent data showed that M2 muscarinic acetylcholine receptor (M2R) stimulation in neonatal rat cardiac myocytes (NRCM) induces the binding of p190RhoGAP to the long isoform of the regulator of G protein signaling 3 (RGS3L). This complex formation alters the substrate preference of p190RhoGAP from RhoA to Rac1. By analyzing carbachol-stimulated GAP activity, we show herein that p190A, but not p190B, alters its substrate preference in NRCM. Based on data that the RhoGAP activity of p190A in endothelial cells is diminished upon nitration by endothelial nitric oxide synthase (eNOS)-derived peroxynitrite, we studied whether carbachol-induced NO/peroxynitrite formation contributes to the carbachol-induced RhoA activation in NRCM. Interestingly, the carbachol-induced RhoA activation in NRCM was suppressed by the eNOS-preferring inhibitor L-NIO as well as the non-selective NOS inhibitor L-NAME. Using L-NIO, we firstly verified the carbachol-induced NO production concurrent with eNOS activation and, secondly, the carbachol-induced nitration of p190A in NRCM. By co-immunoprecipitation, the carbachol-induced complex formation of eNOS, p190A, RGS3L and caveolin-3 was detected. We thus conclude that the NO production by M2R-induced eNOS activation in caveolae in NRCM is required for the nitration of p190A, leading to the binding to RGS3L and the change in substrate preference from RhoA to Rac1. In line with this interpretation, the disruption of caveolae in NRCM by methyl-β-cyclodextrin suppressed carbachol-induced RhoA activation in NRCM to a similar extent as the inhibition of NO production.