Different molecular weight hyaluronic acid alleviates inflammation response in DNFB-induced mice atopic dermatitis and LPS-induced RAW 264.7 cells.

AIMS: Atopic dermatitis (AD) is an inflammatory chronic disease which severely interferes the life of patients. Hence, there is a great need for new therapies. Hyaluronic acid (HA) is an effective potential inflammation modifier; however, there is limited information about their implementation in inflammation therapies. This study aimed to evaluate the anti-inflammatory activities of HA and the influence of its molecular weight. MAIN METHODS: Male C57BL/6 J mice were stimulated by 2,4-dinitrofluorobenzene to induce AD-like symptoms and immune response. The skin lesions and histopathological change, as well as levels of inflammatory factors were evaluated. RAW 264.7 mouse macrophages were treated with lipopolysaccharides (LPS) to induce inflammation. NO, IL-6, and TNF-α levels were detected through ELISA kits. KEY FINDINGS: DNFB challenge induced mice AD symptoms including epidermal thickening, mast cell infiltration, Th2/Th1 immune response, skin lesions IL-4 and IFN-γ, and serum IgE elevation. HA treatment ameliorated such symptoms through the inhibition of PI3K/Akt signaling pathway. LPS induction stimulated the secretion of NO, IL-6, and TNF-α in RAW 264.7 cells, while HA pre-treatment reduced the concentration of the cytokines in cell supernatants. SIGNIFICANCE: These findings give clear insight into the interaction between HA and inflammatory response, which can help guiding the utilization of HA in the AD therapies.

An innovative role for luteolin as a natural quorum sensing inhibitor in Pseudomonas aeruginosa.

AIMS: The emergence of antibiotic tolerance was a tricky problem in the treatment of chronic Pseudomonas aeruginosa-infected cystic fibrosis and burn victims. The quorum sensing (QS) inhibitor may serve as a new tactic for the bacterial resistance by inhibiting the biofilm formation and the production of virulence factors. This study explored the potential of luteolin as a QS inhibitor against P. aeruginosa and the molecular mechanism involved. MAIN METHODS: Crystal violet staining, CLSM observation, and SEM analysis were carried out to assess the effect of luteolin on biofilm formation. The motility assays and the production of virulence factors were determined to evaluate the QS-inhibitory activity of luteolin. Acyl-homoserine lactone, RT-PCR, and molecular docking assays were conducted to explain its anti-QS mechanisms. KEY FINDINGS: The biofilm formation, the production of virulence factors, and the motility of P. aeruginosa could be efficiently inhibited by luteolin. Luteolin could also attenuate the accumulation of the QS-signaling molecules N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL) and N-butanoyl-L-homoserine lactone (BHL) (P < 0.01) and downregulate the transcription levels of QS genes (lasR, lasI, rhlR, and rhlI) (P < 0.01). Molecular docking analysis indicated that luteolin had a greater docking affinity with LasR regulator protein compared with OdDHL. SIGNIFICANCE: This study is important as it reports the molecular mechanisms involved in the anti-biofilm formation activity of luteolin against P. aeruginosa. This study also indicated that luteolin could be helpful when used for the treatment of clinical drug-resistant infections of P. aeruginosa.

28-Noroleanane-derived spirocyclic triterpenoids and iridoid glucosides from the roots of Phlomoides umbrosa (Turcz.) Kamelin & Makhm with their cytotoxic effects.

Four undescribed 23,24-O-isopropylidene-19(18 → 17)-abeo-28-noroleanane-derived spirocyclic triterpenoids and an undescribed 28-noroleanane-derived spirocyclic triterpenoid, together with five known 28-noroleanane-derived spirocyclic triterpenoids, were isolated and identified. In addition, three undescribed iridoid glucosides and four known ones were also identified. All the isolates were identified using spectroscopic techniques, and the absolute configurations of 28-noroleanane-derived spirocyclic triterpenoids were determined by CD method for the first time. Additionally, the alkaline hydrolysis method and HPLC analysis were applied to confirm the moieties of the iridoid glucosides. The fraction and isolates were evaluated for cytotoxic activity on cervical cancer (Hela), human promyelocytic leukemia (HL-60), and breast cancer (MCF-7) cell lines. Among them, phlomisu E possessed an aldehyde group showed the most potent cytotoxic effect with IC50 value less than 10 µM.

Comparative study of selective in vitro and in silico BACE1 inhibitory potential of glycyrrhizin together with its metabolites, 18α- and 18ß-glycyrrhetinic acid, isolated from Hizikia fusiformis.

Hizikia fusiformis (Harvey) Okamura is a brown seaweed widely used in Korea and Japan, and it contains different therapeutically active constituents. In the present study, we investigated the activities of glycyrrhizin isolated from H. fusiformis, including its metabolites, 18α- and 18ß-glycyrrhetinic acid against Alzheimer's disease (AD) via acetyl and butyrylcholinesterase and ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibition. Among these three compounds, 18ß-glycyrrhetinic acid (IC50 = 8.93 ± 0.69 µM) demonstrated two fold potent activity against BACE1 compared to the positive control, quercetin (IC50 = 20.18 ± 0.79 µM). Additionally, glycyrrhizin with an IC50 value of 20.12 ± 1.87 µM showed similarity to quercetin, while 18α-glycyrrhetinic acid showed moderate activity (IC50 = 104.35 ± 2.84 µM). A kinetic study revealed that glycyrrhizin and 18ß-glycyrrhetinic acid were non-competitive and competitive inhibitiors of BACE1, demonstrated via K i values of 16.92 and 10.91 µM, respectively. Molecular docking simulation studies evidently revealed strong binding energy of these compounds for BACE1, indicating their high affinity and capacity for tighter binding to the active site of the enzyme. These data suggest that glycyrrhizin isolated from the edible seaweed, H. fusiformis and its metabolite, 18ß-glycyrrhetinic acid demonstrated selective inhibitory activity against BACE1 to alleviate AD.

A comparative study of Mentha arvensis L. and Mentha haplocalyx Briq. by HPLC.

We have developed a new method to simultaneously determine five marker compounds in Menthae Herba via HPLC/PDA - including hesperidin (1), rosmarinic acid (2), diosmin (3), didymin (4) and buddleoside (5). The newly developed method was successfully used to analyse for two species (Mentha arvensis L. and Mentha haplocalyx Briq.) of Menthae Herba, and the satisfactory results were obtained from the validation of developed method. The pattern analysis could greatly discriminate between M. arvensis L. and M. haplocalyx Briq. In conclusion, the proposed HPLC/PDA method is suitable for quality evaluation of Menthae Herba.

Protein tyrosine phosphatase 1B inhibitors from natural sources.

Since PTP1B enzyme was discovered in 1988, it has captured the research community's attention. This landmark discovery has stimulated numerous research studies on a variety of human diseases, including cancer, inflammation, and diabetes. Tremendous progress has been made in finding PTP1B inhibitors and exploring PTP1B regulatory mechanisms. This review investigates for the natural PTP1B inhibitors, and focuses on the common characteristics of the discovered structures and structure-activity relationships. To facilitate understanding, all the natural compounds are here divided into five different classes (fatty acids, phenolics, terpenoids, steroids, and alkaloids), according to their skeletons. These PTP1B inhibitors of scaffold structures could serve as a theoretical basis for new concept drug discovery and design.

A new lignan and a new alkaloid, and α-glucosidase inhibitory compounds from the grains of Echinochloa utilis Ohwi & Yabuno.

A new lignan, utilisin (1), and a new alkaloid, echinoutilin (2), together with eleven known compounds 3-13 were isolated from the grains of Echinochloa utilis Ohwi & Yabuno. Their structures were identified through the analysis of spectroscopic data. The absolute configuration of 2 was determined by Mosher's method. These compounds were evaluated for α-glucosidase inhibitory activity. Among them, compounds 2, 3 and 6 exhibited considerable α-glucosidase inhibitory activity with IC50 values of 42.1±1.3, 58.9±3.7, and 40.9±1.1µM, respectively. The results indicate that the grains of E. utilis will be useful in the treatment of diabetes control agents.

Inhibitory effects of serratene-type triterpenoids from Lycopodium complanatum on cholinesterases and ß-secretase 1.

Phytochemical investigation of Lycopodium complanatum whole plants led to the isolation of two new serratene-type triterpenoids (1 and 2) along with eight known triterpenoids (3-10). Their structures were established using 1D and 2D NMR spectroscopic techniques and mass spectrometry. These compounds did not inhibit acetylcholinesterases (AChE) and butyrylcholinesterase (BChE), but did inhibit ß-secretase 1 (BACE1). Compounds 1 and 6 showed potent BACE1 inhibition with IC50 values of 2.79 ± 0.28 and 2.49 ± 0.12 µM, respectively. The kinetic study of BACE1 inhibition revealed that compound 1 showed competitive inhibition, whereas 6 showed mixed-type inhibition. Furthermore, molecular docking results showed that the tested inhibitors 1 and 6 exhibited good binding affinities toward BACE1, with binding energies of -8.8 and -10.3 kcal/mol, respectively.

Triterpenoids and sterols from the grains of Echinochloa utilis Ohwi & Yabuno and their cytotoxic activity.

Two new tetracyclic triterpenoids, echinochlorins C (1) and D (2), and sawamilletin (3) with new spectroscopic data were isolated from Echinochloa utilis Ohwi & Yabuno grains, along with one known triterpenoid (4) and eight sterols (5-12). Their structures were elucidated by spectroscopic data analyses (IR, UV, MS, and NMR). These compounds were tested in vitro cytotoxic activities against the human tumor-cell lines (HeLa, HL-60, and MCF-7). Compounds 6 and 8 displayed potential cytotoxic activity against HeLa, with IC50 values of 3.1±0.9 and 3.2±0.8µM, respectively. This finding indicated that tetracyclic triterpenoids isolated from E. utilis may have potential beneficial effects for the treatment of cancer.

Flavanonol glucosides from the aerial parts of Agrimonia pilosa Ledeb. and their acetylcholinesterase inhibitory effects.

Two new flavanonol glucoside isomers, (2R,3S)-dihydrokaempferol 3-O-ß-D-glucoside (1) and (2S,3R)-dihydrokaempferol 3-O-ß-D-glucoside (2), were isolated from the aerial parts of Agrimonia pilosa Ledeb., along with eight known flavanonol glucosides (3-10). Their structures were determined on the basis of spectroscopic analysis. In addition, these compounds were evaluated to determine their acetylcholinesterase inhibitory activities. The results indicated that these compounds have moderate inhibitory effects, with IC50 values ranging from 76.59 ± 1.16 to 97.53 ± 1.64 µM, except compounds 1 and 4 were inactive.

PTP1B inhibitors from Selaginella tamariscina (Beauv.) Spring and their kinetic properties and molecular docking simulation.

Diabetes is one of the most popular worldwide diseases, regulated by the defects in insulin secretion, insulin action, or both. The overexpression of protein tyrosine phosphatase 1B (PTP1B) was found to down-regulate the insulin-receptor activation. PTP1B has been known as a strategy for the treatment of diabetes via the regulation of insulin signal transduction pathway. Herein, we investigated the PTP1B inhibitors isolated from natural sources. The chemical investigation of Selaginella tamariscina (Beauv.) Spring revealed seven unsaturated alkynyl phenols 1-7, four new selaginellins T-W 1-4 together with three known compounds 5-7 isolated from the aerial parts. The structures of the isolates were determined by spectroscopic techniques (1D/2D-NMR, MS, and CD). The inhibitory effects of these isolates on the PTP1B enzyme activity were investigated. Among them, compounds 2-7 significantly exhibited the inhibitory effects with the IC50 values ranging from 4.8 to 15.9µM. Compound 1 moderately displayed the inhibitory activity with an IC50 of 57.9µM. Furthermore, active compounds were discovered from their kinetic and molecular docking analysis. The results revealed that compounds 2 and 4-7 were mixed-competitive inhibitors, whereas compound 3 was a non-competitive inhibitor. This data confirm that these compounds exhibited potential inhibitory effect on the PTP1B enzyme activity.

Ellagitannin and flavonoid constituents from Agrimonia pilosa Ledeb. with their protein tyrosine phosphatase and acetylcholinesterase inhibitory activities.

A new ellagitannin, agritannin (1), a new flavone glycoside, agriflavone (2), and another flavone glycoside with spectroscopic data reported for the first time, kaempferol-3-O-[(S)-3-hydroxy-3-methylglutaryl (1→6)]-ß-d-glucoside (3), along with 16 known compounds were isolated from the aerial parts of Agrimonia pilosa Ledeb. These compounds were evaluated for PTP1B inhibitory activity. Among them, compounds 9 and 18 displayed potential inhibitory activity against PTP1B with IC50 values of 7.14±1.75 and 7.73±0.24µM, respectively. In addition, compound 1 showed significant inhibitory effect with an IC50 value of 17.03±0.09µM. Furthermore, these compounds were tested in AChE inhibitory assays. Most of them were found to have moderate inhibitory effects, with IC50 values ranging from 60.20±1.09 to 92.85±1.12µM. Except compounds 3, 8, and 18 were inactive.

Lignan derivatives from Selaginella tamariscina and their nitric oxide inhibitory effects in LPS-stimulated RAW 264.7 cells.

The chemical characterization of Selaginella tamariscina leaves resulted in the isolation of five lignanoside derivatives (1-4 and 6) and one neolignan (5). These compounds include three new lignanosides, tamariscinosides D-F (1-3), and one liriodendrin (4) that were isolated for the first time from this plant, together with two known compounds, (2R,3S)-dihydro-2-(3,5-dimethoxy-4-hydroxyphenyl)-7-methoxy-5-acetyl-benzofuran (5) and moellenoside B (6). The chemical structures of these isolated compounds were determined using 1D and 2D NMR, MS, and CD spectroscopic data, and the results were compared to data previously reported in the literatures. These compounds were also evaluated in terms of their inhibition of NO production in lipopolysaccharide (LPS)-stimulated activity in the macrophage cell line RAW 264.7. Among them, compounds 1, 2, 5, and 6 exhibited a significant inhibition with IC50 values ranging from 32.3 to 55.8µM.

Effects of Constituent Compounds of Smilax china on Nicotine-Induced Endothelial Dysfunction in Human Umbilical Vein Endothelial Cells.

This study investigated the effects of compounds isolated from 70% ethanol (EtOH) extraction of Smilax china L. (SCE), a plant belonging to the family Smilacaceae on nicotine-induced endothelial dysfunction (ED) in human umbilical vein endothelial cells. We isolated 10 compounds from ethyl acetate (EtOAc) fraction of 70% EtOH extract of SCE and investigated their inhibitory effect on nicotine-induced ED in endothelial cells. Kaempferol, kaempferol 7-O-α-L-rhamnopyranoside, puerarin and ferulic acid showed strong inhibition of nicotine-induced vascular cell adhesion molecule (VCAM-1) expression while kaempferol, kaempferin, and caffeic acid attenuated intercellular adhesion molecule (ICAM-1) expression. Lepidoside, caffeic acid and methylsuccinic acid caused the highest up-regulated expression of endothelial nitric oxide synthase at the protein level with caffeic acid and ferulic acid showing strong inhibitory effects on inducible nitric oxide synthase (iNOS) expression. In addition, ferulic acid and kaempferol showed inhibition against interleukin-8 (IL-8) and interleukin-1ß (IL-1ß) expression while ferulic acid and caffeic acid showed comparatively higher inhibition of ED associated tumor necrosis factor-α (TNF-α) expression. These results show the potential of the aforementioned compounds to reverse the toxic effects of nicotine on the endothelium.

PTP1B, α-glucosidase, and DPP-IV inhibitory effects for chromene derivatives from the leaves of Smilax china L.

Two new flavonoids, bismilachinone (11) and smilachinin (14), were isolated from the leaves of Smilax china L. together with 14 known compounds. Their structures were elucidated using spectroscopic methods. The PTP1B, α-glucosidase, and DPP-IV inhibitory activities of compounds 1-16 were evaluated at the molecular level. Among them, compounds 4, 7, and 10 showed moderate DPP-IV inhibitory activities with IC50 values of 20.81, 33.12, and 32.93 µM, respectively. Compounds 3, 4, 6, 11, 12, and 16 showed strong PTP1B inhibitory activities, with respective IC50 values of 7.62, 10.80, 0.92, 2.68, 9.77, and 24.17 µM compared with the IC50 value for the positive control (ursolic acid: IC50 = 1.21 µM). Compounds 2-7, 11, 12, 15, and 16 showed potent α-glucosidase inhibitory activities, with respective IC50 values of 8.70, 81.66, 35.11, 35.92, 7.99, 26.28, 11.28, 62.68, 44.32, and 70.12 µM. The positive control, acarbose, displayed an IC50 value of 175.84 µM. In the kinetic study for the PTP1B enzyme, compounds 6, 11, and 12 displayed competitive inhibition with Ki values of 3.20, 8.56, and 5.86 µM, respectively. Compounds 3, 4, and 16 showed noncompetitive inhibition with Ki values of 18.75, 5.95, and 22.86 µM, respectively. Molecular docking study for the competitive inhibitors (6, 11, and 12) radically corroborates the binding affinities and inhibition of PTP1B enzymes. These results indicated that the leaves of Smilax china L. may contain compounds with anti-diabetic activity.

Simultaneous analysis of seven marker compounds from Saposhnikoviae Radix, Glehniae Radix and Peucedani Japonici Radix by HPLC/PDA.

A new combination of high performance liquid chromatography (HPLC) method coupled with photodiode array (PDA) analysis has been developed for the simultaneous quantitative determination of seven major components in Saposhnikoviae Radix (SR), Glehniae Radix (GR) and Peucedani Japonici Radix (PR), namely peucedanol 7-O-ß-D-glucopyranoside (1), prim-O-glucosylcimifugin (2), cimifugin (3), 4'-O-ß-D-glucosyl-5-O-methylvisamminol (4), bergapten (5), sec-O-glucosylhamaudol (6), and imperatorin (7). Clear separation of these seven components were achieved on a Phenomenex Kinetex C18 (250 × 4.6 mm, 5 µm) column by gradient elution of water (A) and methanol (B) as mobile phase. The flow rate was 1.0 mL/min and the UV detector wavelength was set at 254 nm. The method was successfully used in the analysis of SR, GR, and PR with relatively simple conditions and procedures, and the results were satisfactory for linearity, recovery, precision, accuracy, stability and robustness. The results indicate that the established HPLC/PDA method is suitable for the classification of SR, GR, and PR.

Isolation of Lignan and Fatty Acid Derivatives from the Grains of Echinochloa utilis and Their Inhibition of Lipopolysaccharide-Induced Nitric Oxide Production in RAW 264.7 Cells.

Two new fatty acid derivatives, echinochlorins A (8) and B (9) and a racemic lignan, (±)-anti-1-(4-hydroxy-3-methoxyphenyl)-2-{4-[(E)-3-acetoxypropen-1-yl]-2-methoxyphenoxy}propan-1,3-diol 3-acetate (1), were isolated from Echinochloa utilis grains, along with six known lignans (2-7) and two fatty acid derivatives (10, 11). Their structures were established by spectroscopic data analyses (IR, UV, HR-FABMS, GC-MS, and 1D and 2D NMR). The configuration of 1 was determined by Mosher's method. Compound 5 displayed potential inhibitory activity on lipopolysaccharide-induced NO production in macrophage RAW 264.7 cells with an IC50 value of 4.8 ± 0.5 µM. These isolated compounds in crude EtOH extract were also quantitated by HPLC.

Anti-inflammatory terpenylated coumarins from the leaves of Zanthoxylum schinifolium with α-glucosidase inhibitory activity.

Nine terpenylated coumarins, namely 7-[(E)-3',7'-dimethyl-6'-oxo-2',7'-octadienyl]oxy-coumarin (1), schinilenol (2), schinindiol (3), collinin (4), 7-[(E)-7'-hydroxy-3',7'-dimethy-locta-2',5'-dienyloxy]-coumarin (5), 8-methoxyanisocoumarin (6), 7-(6'R-hydroxy-3',7'-dimethyl-2'E,7'-octadienyloxy)coumarin (7), (E)-4-methyl-6-(coumarin-7'-yloxy)hex-4-enal (8), and aurapten (9), along with a 4-quinolone alkaloid (10) and integrifoliodiol (11), were isolated from the leaves of Zanthoxylum schinifolium. Of the isolates, compounds 4 and 7 potentially inhibited NO production in lipopolysaccharide (LPS)-stimulated macrophage RAW264.7 cells, with IC50 values of 5.9 ± 0.8 and 18.2 ± 1.8 µM, respectively. Furthermore, compounds 4 and 7 dose-dependently reduced the LPS-induced iNOS expression. Moreover, pre-incubation of cells with 4 and 7 significantly suppressed LPS-induced COX-2 protein expression. In addition, compounds 4, 7, 8, and 10 showed strong α-glucosidase inhibitory effects, with IC50 values of 92.1 ± 0.7, 90.6 ± 0.9, 78.2 ± 0.2, and 82.4 ± 0.8 µM, respectively. Compounds 1, 5, and 11 displayed moderate effects with IC50 values of 161.6 ± 0.3, 164.4 ± 1.1, and 155.4 ± 0.9 µM, while acarbose, a positive control, possessed an IC50 value of 121.5 ± 1.0 µM. This is the first investigation on the α-glucosidase inhibitory effect of components from Zanthoxylum schinifolium. Further studies should be made on active compounds.

Protein tyrosine phosphatase 1B (PTP1B) inhibitory activity and glucosidase inhibitory activity of compounds isolated from Agrimonia pilosa.

CONTEXT: Despite phytochemical studies of Agrimonia pilosa Ledeb. (Rosaceae), the antidiabetic effects of this plant are unknown. OBJECTIVE: This study characterizes the isolated compounds from the aerial parts of A. pilosa and evaluates their PTP1B and α-glucosidase inhibitory properties. MATERIALS AND METHODS: Ethanol extract of A. pilosa was found to inhibit 64% PTP1B activity at 30 µg/mL. The ethanol extract was partitioned with methylene chloride, ethyl acetate, n-butanol, and water fractions. Among these, the ethyl acetate fraction displayed the most potent PTP1B activity. The ethyl acetate extract was separated by chromatographic methods to obtain flavonoids and triterpenoids (1-11); which were evaluated for their inhibitory effects on PTP1B activity with p-nitrophenyl phosphate (p-NPP) as a substrate, and also α-glucosidase enzyme. RESULTS: Compounds 1-11 were identified as apigenin-7-O-ß-d-glucuronide-6″-methyl ester, triliroside, quercetin-7-O-ß-d-glycoside, quercetin-3-O-ß-d-glycoside, kaempferol, kaempferol-3-O-α-l-rhamnoside, ß-sitosterol, ursolic acid, tormentic acid, methyl 2-hydroxyl tricosanoate, and palmitic acid. Compounds 8, 9, and 11 displayed inhibitory effects on PTP1B activity with IC50 values of 3.47 ± 0.02, 0.50 ± 0.06, and 0.10 ± 0.03 µM, respectively. Compounds 3, 4, 6, and 9 exhibited inhibition of the α-glucosidase activity with IC50 values of 11.2 ± 0.2, 29.6 ± 0.9, 28.5 ± 0.1, and 23.8 ± 0.4 µM, respectively. DISCUSSION AND CONCLUSION: As major ingredients of A. pilosa, compounds 1, 6, 8, and 9 showed the greatest inhibitory potency on PTP1B activity. Compounds 3, 6, 8, and 9 also showed potent inhibitory effects on α-glucosidase enzyme. This result suggested the potential of these compounds for developing antidiabetic agents.

Simultaneous quantitation and validation of method for the quality evaluation of Eucommiae cortex by HPLC/UV.

A new HPLC/UV method has been developed for the simultaneous quantitative determination of four major components in Eucommiae cortex, namely geniposidic acid (1), geniposide (2), pinoresinol di-O-ß-D-glucopyranoside (3), and liriodendrin (4). Simultaneous separations of these four components were achieved on a J'sphere ODS C(18) column (250 × 4.6 mm, 4 µm). The elution was done using water with 0.1% phosphoric acid (A) and acetonitrile with 0.1% phosphoric acid (B) in a two-step elution of the mobile phase at a flow rate of 1.0 mL/min and a wavelength of 230 nm. The method was validated for linearity, recovery, precision, accuracy, stability and robustness. All calibration curves showed good linear regression (r(2) > 0.999) within the test ranges. This method showed good recovery and reproducibility for the quantification of these four components in 85 species of Eucommiae cortex. The intra-day and inter-day precisions were lower than 0.53% (as a relative standard deviation, RSD) and accuracies between 93.00 and 106.28% for all standards. The results indicate that the established HPLC/UV method is suitable for quantitation and quality evaluation of Eucommiae cortex.