Ethanol extract from Astilbe chinensis inflorescence suppresses inflammation in macrophages and growth of oral pathogenic bacteria.

Chronic oral inflammation and biofilm-mediated infections drive diseases such as dental caries and periodontitis. This study investigated the anti-inflammatory and antibacterial potential of an ethanol extract from Astilbe chinensis inflorescence (GA-13-6) as a prominent candidate for natural complex substances (NCS) with therapeutic potential. In LPS-stimulated RAW 264.7 macrophages, GA-13-6 significantly suppressed proinflammatory mediators, including interleukin-6 (IL-6), tumor necrosis factor (TNF), and nitric oxide (NO), surpassing purified astilbin, a known bioactive compound found in A. chinensis. Furthermore, GA-13-6 downregulated the expression of cyclooxygenase-2 (COX2) and inducible nitric oxide synthase (iNOS), indicating an inhibitory effect on the inflammatory cascade. Remarkably, GA-13-6 exhibited selective antibacterial activity against Streptococcus mutans, Streptococcus sanguinis, and Porphyromonas gingivalis, key players in dental caries and periodontitis, respectively. These findings suggest that complex GA-13-6 holds the potential for the treatment or prevention of periodontal and dental diseases, as well as various other inflammation-related conditions, while averting the induction of antibiotic resistance.

Aiouea padiformis extract exhibits anti-inflammatory effects by inhibiting the ATPase activity of NLRP3.

Inflammation is implicated as a cause in many diseases. Most of the anti-inflammatory agents in use are synthetic and there is an unmet need for natural substance-derived anti-inflammatory agents with minimal side effects. Aiouea padiformis belongs to the Lauraceae family and is primarily found in tropical regions. While some members of the Aiouea genus are known to possess anti-inflammatory properties, the anti-inflammatory properties of Aiouea padiformis extract (AP) have not been investigated. In this study, we aimed to examine the anti-inflammatory function of AP through the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome and elucidate the underlying mechanisms. Treatment with AP inhibited the secretion of interleukin-1 beta (IL-1ß) mediated by NLRP3 inflammasome in J774A.1 and THP-1 cells without affecting the viability. In addition, AP treatment did not influence NF-κB signaling, potassium efflux, or intracellular reactive oxygen species (ROS) production-all of which are associated with NLRP3 inflammasome activation. However, intriguingly, AP treatment significantly reduced the ATPase activity of NLRP3, leading to the inhibition of ASC oligomerization and speck formation. Consistent with cellular experiments, the anti-inflammatory property of AP in vivo was also evaluated using an LPS-induced inflammation model in zebrafish, demonstrating that AP hinders NLRP3 inflammasome activation.

Anti-Adipogenic Activity of Secondary Metabolites Isolated from Smilax sieboldii Miq. on 3T3-L1 Adipocytes.

Smilax sieboldii, a climbing tree belonging to Smilacaceae, has been used in traditional oriental medicine for treating arthritis, tumors, leprosy, psoriasis, and lumbago. To evaluate the anti-obesity effects of S. sieboldii (Smilacaceae), we screened methylene chloride (CH2Cl2), ethyl acetate (EtOAc), aqueous-saturated n-butanol, and ethanol (EtOH) extracts of the whole plant at various concentrations to inhibit adipogenesis in adipocytes. The 3T3-L1 cell line with Oil red O staining with the help of fluorometry was used as an indicator of anti-obesity activity. Bioactivity-guided fractionation of the EtOH extract and subsequent phytochemical investigation of the active CH2Cl2- and EtOAc-soluble fractions resulted in the isolation of 19 secondary metabolites (1-19), including a new α-hydroxy acid derivative (16) and two new lanostane-type triterpenoids (17 and 18). The structures of these compounds were characterized using various spectroscopic methods. All the isolated compounds were screened for adipogenesis inhibition at a concentration of 100 µM. Of these, compounds 1, 2, 4-9, 15, and 19 significantly reduced fat accumulation in 3T3-L1 adipocytes, especially compounds 4, 7, 9, and 19, showing 37.05 ± 0.95, 8.60 ± 0.41 15.82 ± 1.23, and 17.73 ± 1.28% lipid content, respectively, at a concentration of 100 µM. These findings provide experimental evidence that isolates from S. sieboldii extracts exert beneficial effects regarding the regulation of adipocyte differentiation.

Tetracera loureiri Extract Regulates Lipopolysaccharide-Induced Inflammatory Response Via Nuclear Factor-κB and Mitogen Activated Protein Kinase Signaling Pathways.

Tetracera loureiri (T. loureiri) is a woody climber inhabiting open deciduous or evergreen forests in Southeast Asia. A decoction comprising its stem and other herbs is a traditional Thai remedy for fatigue and jaundice, as well as to promote overall health. Anti-inflammatory effects induced by T. loureiri extract have not been reported. In this study, we investigated the anti-inflammatory effect of an ethanol extract of T. loureiri (ETL) on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 macrophages. We found that ETL treatment inhibited the production of nitric oxide (NO) in LPS-stimulated RAW264.7 cells, without affecting cell viability. The effect of ETL on the expression of various pro-inflammatory mediators was analyzed using reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA). We observed that ETL inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the mRNA and protein levels and decreased the production of prostaglandin E2 (PGE2) by COX-2 in RAW264.7 macrophages. ETL dose-dependently reduced the production of pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) in LPS-induced RAW264.7 cells, in a dose-dependent manner. Furthermore, ETL suppressed the LPS-induced nuclear translocation of the nuclear factor, NF-κB. Additionally, ETL was found to inhibit the activation of mitogen-activated protein kinases (MAPK), such as extracellular signal-regulated kinase, c-Jun-N-terminal kinase, and p38 MAPK. In conclusion, our findings demonstrate that ETL inhibits the expression of pro-inflammatory mediators and cytokines, thereby downregulating NF-κB and MAPK signaling pathways in LPS-stimulated macrophages, Consequently, ETL is a potential therapeutic agent for the treatment of inflammatory diseases.

A novel role for α-viniferin in suppressing angiogenesis by blocking the VEGFR-2/p70S6K signaling pathway.

Angiogenesis plays important roles in pathological conditions such as cancer and inflammation as well as normal tissue development and homeostasis. Here, we investigated the effects and molecular mechanisms of α-viniferin, an oligostilbene isolated from Caragana sinica, on human umbilical vein endothelial cell responses in vitro and angiogenic sprouting in aortic rings ex vivo. α-viniferin treatment inhibited mitogen-induced HUVEC proliferation by retinoblastoma protein hypophosphorylation. In addition, α-viniferin suppressed mitogen-induced HUVEC adhesion, migration, invasion, and microvessel outgrowth. These anti-angiogenic activities of α-viniferin might be mediated through downregulation of cell cycle-related proteins, vascular endothelial growth factor receptor-2 (VEGFR-2), and matrix metalloproteinase-2. Furthermore, inactivation of VEGFR-2/p70 ribosomal S6 kinase signaling pathway was found to be involved in α-viniferin-mediated modulation of endothelial cell responses. Our results demonstrate the pharmacological functions and molecular mechanisms of α-viniferin in regulating angiogenesis, suggesting the therapeutic potential of α-viniferin to treat and prevent various angiogenesis-related diseases.

Benzylideneacetone Derivatives Inhibit Osteoclastogenesis and Activate Osteoblastogenesis Independently Based on Specific Structure-Activity Relationship.

(E)-3,4-Dihydroxybenzylideneacetone (compound 1) inhibited receptor activator of NF-κB ligand-induced osteoclastogenesis of C57BL/6 bone marrow monocyte/macrophages with IC50 of 7.8 µM (IC50 of alendronate, 3.7 µM) while stimulating the differentiation of MC3T3-E1 osteoblastic cells, accompanied by the induction of Runt-related transcription factor 2, alkaline phosphatase, and osteocalcin. (E)-4-(3-Hydroxy-4-methoxyphenyl)-3-buten-2-one (compound 2c) showed a dramatically increased osteoclast-inhibitory potency with IC50 of 0.11 µM while sustaining osteoblast-stimulatory activity. (E)-4-(4-Hydroxy-3-methoxyphenyl)-3-buten-2-one (compound 2g) stimulated alkaline phosphatase production 2-fold at 50 µM without changing osteoclast-inhibitory activity, compared with compound 1. Oral administration of compounds 1, 2c, and 2g prevented ovariectomy-induced osteoporosis in ddY mice to a degree proportional to their osteoclastogenesis-inhibitory potencies. The administration of 1 (mg/kg)/d compound 2c ameliorated histomorphometry of osteoporotic bone to a degree comparable with 10 (mg/kg)/d alendronate. Conclusively, the in vitro capacity of a few benzylideneacetone derivatives to inhibit osteoclastogenesis supported by independent osteoblastogenesis activation was convincingly reflected in in vivo management of osteoporosis, suggesting a potential novel therapeutics for osteopenic diseases.

Marine Alga Ecklonia cava Extract and Dieckol Attenuate Prostaglandin E2 Production in HaCaT Keratinocytes Exposed to Airborne Particulate Matter.

Atmospheric particulate matter (PM) is an important cause of skin damage, and an increasing number of studies have been conducted to discover safe, natural materials that can alleviate the oxidative stress and inflammation caused by PM. It has been previously shown that the extract of Ecklonia cava Kjellman, a perennial brown macroalga, can alleviate oxidative stress in epidermal keratinocytes exposed to PM less than 10 microns in diameter (PM10). The present study was undertaken to further examine the anti-inflammatory effects of E. cava extract and its major polyphenolic constituent, dieckol. HaCaT keratinocytes were exposed to PM10 in the presence or absence of E. cava extract or dieckol and analyzed for their viability, prostaglandin E2 (PGE2) release, and gene expression of cyclooxygenase (COX)-1, COX-2, microsomal prostaglandin E2 synthase (mPGES)-1, mPGES-2, and cytosolic prostaglandin E2 synthase (cPGES). PM10 treatment decreased cell viability and increased the production of PGE2, and these changes were partially abrogated by E. cava extract. E. cava extract also attenuated the expression of COX-1, COX-2, and mPGES-2 stimulated by PM10. Dieckol attenuated PGE2 production and the gene expression of COX-1, COX-2, and mPGES-1 stimulated by PM10. This study demonstrates that E. cava extract and dieckol alleviate airborne PM10-induced PGE2 production in keratinocytes through the inhibition of gene expression of COX-1, COX-2, mPGES-1, and/or mPGES-2. Thus, E. cava extract and dieckol are potentially useful natural cosmetic ingredients for counteracting the pro-inflammatory effects of airborne PM.

Glycopentanolones A-D, four new geranylated quinolone alkaloids from Glycosmis pentaphylla.

The ethanolic extract obtained from the stems of Glycosmis pentaphylla was found to suppress antigen-mediated degranulation of rat basophilic leukemia (RBL-2H3) cells. Four new geranylated 2-quinolone alkaloids, named glycopentanolones A-D (1-4), and 12 known metabolites (5-16) were isolated from the ethanolic extract from the stems of G. pentaphylla using bioassay-guided fractionation. Their structures were elucidated by a combination of 1D and 2D NMR, and HRESI-MS. The inhibitory effects of the isolated constituents on ß-hexosaminidase release from RBL-2H3 cells were examined, and compounds 1, 5, 8 and 11 exhibited potent inhibitory activity with IC50 values between 0.05 and 4.28 µM.

Luteolin 7-Sulfate Attenuates Melanin Synthesis through Inhibition of CREB- and MITF-Mediated Tyrosinase Expression.

Antioxidants with antimelanogenic activity are potentially useful for the attenuation of skin hyperpigmentation disorders. In a previous study, luteolin 7-sulfate isolated from Phyllospadix iwatensis Makino, a marine plant, was shown to inhibit cellular melanin synthesis. The aim of the present study was to examine its action mechanism, focusing on the regulation of tyrosinase (TYR) expression in cells. Cell-based assay was undertaken using murine melanoma B16-F10 cells and primary human epidermal melanocytes (HEMs). Luteolin 7-sulfate showed lower toxicity compared to luteolin in B16-F10 cells. At the non-toxic concentration ranges, luteolin 7-sulfate attenuated melanin synthesis, stimulated by α-melanocyte-stimulating hormone or forskolin. Luteolin 7-sulfate attenuated forskolin-induced microphthalmia-associated transcription factor (MITF) and TYR expressions at the mRNA and protein levels in B16-F10 cells. It also attenuated the phosphorylation of cAMP-responsive element binding protein (CREB) stimulated by forskolin. Luteolin 7-sulfate also attenuated melanin synthesis in primary HEMs. This study demonstrates that luteolin 7-sulfate attenuates TYR gene expression through the intervention of a CREB- and MITF-mediated signaling pathway, leading to the decreased melanin synthesis.

Inhibition of ß-site amyloid precursor protein cleaving enzyme 1 and cholinesterases by pterosins via a specific structure-activity relationship with a strong BBB permeability.

We extracted 15 pterosin derivatives from Pteridium aquilinum that inhibited ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) and cholinesterases involved in the pathogenesis of Alzheimer's disease (AD). (2R)-Pterosin B inhibited BACE1, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with an IC50 of 29.6, 16.2 and 48.1 µM, respectively. The Ki values and binding energies (kcal/mol) between pterosins and BACE1, AChE, and BChE corresponded to the respective IC50 values. (2R)-Pterosin B was a noncompetitive inhibitor against human BACE1 and BChE as well as a mixed-type inhibitor against AChE, binding to the active sites of the corresponding enzymes. Molecular docking simulation of mixed-type and noncompetitive inhibitors for BACE1, AChE, and BChE indicated novel binding site-directed inhibition of the enzymes by pterosins and the structure-activity relationship. (2R)-Pterosin B exhibited a strong BBB permeability with an effective permeability (Pe) of 60.3×10-6 cm/s on PAMPA-BBB. (2R)-Pterosin B and (2R,3 R)-pteroside C significantly decreased the secretion of Aß peptides from neuroblastoma cells that overexpressed human ß-amyloid precursor protein at 500 µM. Conclusively, our study suggested that several pterosins are potential scaffolds for multitarget-directed ligands (MTDLs) for AD therapeutics.

Anti-Obesity Activity of Saringosterol Isolated from Sargassum muticum (Yendo) Fensholt Extract in 3T3-L1 Cells.

Saringosterol, a steroid isolated from Sargassum muticum, a brown edible alga widely distributed on the seashores of southern and eastern Korea, has been shown to exhibit anti-obesity effect. In this study, we investigated the anti-obesity activity of saringosterol through various experiments. The inhibitory effect of saringosterol on adipogenesis was evaluated via Oil Red O staining in 3T3-L1 preadipocytes. After confirming that saringosterol is not cytotoxic to these cells by using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, the effect of saringosterol on the expression of various adipogenesis-related genes was analyzed via quantitative real-time polymerase chain reaction and western blotting. We demonstrated that saringosterol dose dependently inhibited adipocyte differentiation and expression of adipogenic marker genes such as adipocyte fatty acid-binding protein, adiponectin, resistin, and fatty acid synthase in 3T3-L1 cells. In addition, saringosterol significantly inhibited the mRNA and protein expression of peroxisome proliferator-activated receptor γ and CCAAT enhancer-binding protein α in 3T3-L1 cells. Collectively, these findings indicate that saringosterol isolated from S. muticum exhibits anti-obesity effect by inhibiting the expression of adipogenic transcription factors and marker genes and that it may be developed as a drug to suppress adipogenesis. Copyright © 2017 John Wiley & Sons, Ltd.

Anti-inflammatory effect of tribulusamide D isolated from Tribulus terrestris in lipopolysaccharide-stimulated RAW264.7 macrophages.

Tribulus terrestris (T. terrestris) has been used as a traditional medicine for the treatment of a variety of diseases, including inflammation, edema and hypertension. The aqueous and ethanol extracts of T. terrestris contain alkaloids, flavonoids, tannins, quinines and phenolic compounds. Tribulusamide D is a compound that has been isolated from the ethanol extract of T. terrestris. The present study investigated the anti­inflammatory effect of tribulusamide D on lipopolysaccharide (LPS)­stimulated RAW 264.7 macrophages. Tribulusamide D inhibited the production of LPS­induced nitric oxide and prostaglandin E2, by reducing the expression of inducible nitric oxide synthase and cyclooxygenase­2 expression, respectively. The expression of these genes associated with inflammation was determined using reverse transcription­polymerase chain reaction and western blot analysis. Furthermore, tribulusamide D reduced the expression of LPS­induced inflammatory cytokines, including interleukin (IL)­6, IL­10 and tumor necrosis factor­α. They were quantified using an enzyme­linked immunosorbent assay. In addition, the present study confirmed that the inhibitory effects of tribulusamide D on the inflammatory response were mediated through inactivation of mitogen­activated protein kinase p38 and inhibition of nuclear localization of nuclear factor­B, which were also determined by western blot analysis. To the best of our knowledge, the current study is the first to demonstrate that tribulusamide D exerts anti­inflammatory activity by altering the expression of inflammatory mediators and cytokines, indicating that tribulusamide D could be developed as a potential therapeutic agent for the treatment of inflammatory disorders.

Ulmus davidiana Nakai induces apoptosis and autophagy on non-small cell lung cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Ulmus davidiana Nakai (UDN) is frequently used in the treatment of cancer in traditional oriental medicine. Although several reports indicate that UDN has inhibitory effects in some cancers, there has been no report on the inhibitory effects of UDN via both autophagy and apoptosis. MATERIALS AND METHODS: Cytotoxicity induced by UDN in human non-small cell lung cancer (NSCLC) H-1299 and H-460 cell lines was evaluated using the 2, 3-Bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide inner salt (XTT) assay and trypan blue exclusion assay. Induction of apoptosis was also investigated using Hoechst staining and annexin-V binding assay and was confirmed with western blot analysis. Induction of autophagy was investigated through observation of autophagy vacuoles under inverted phase-contrast microscopy and was confirmed by observing the formation of autophagy vacuoles under a fluorescence microscope using monodansylcadaverine (MDC) staining and western blot analysis. The in vivo anti-tumorigenic effect of UDN was investigated in an athymic nude mouse xenograft model using H-1299 NSCLC cells. RESULTS: UDN exhibited a marked inhibitory effect on cell growth in H-1299 and H-460 human NSCLC cell lines in a dose- and time-dependent manner in vitro and in vivo. It induced not only apoptosis, but also autophagy in both H-1299 and H-460 cells in a dose-dependent manner. UDN-mediated autophagy led to the accumulation of autophagosome, resulting in apoptosis induction and cell death. CONCLUSIONS: From our current knowledge, we are the first to demonstrate that UDN has the potential to induce both autophagy and apoptosis in H-1299 and H-460 human NSCLC cell lines. We suggest that UDN can be considered a potential candidate for lung cancer-specific chemotherapy with efficacy as a cytotoxic agent.

Anti-melanogenic effects of resveratryl triglycolate, a novel hybrid compound derived by esterification of resveratrol with glycolic acid.

Resveratrol is known to inhibit cellular melanin synthesis by multiple mechanisms. Glycolic acid (GA) is used in skin care products for its excellent skin penetration. The purpose of this study was to examine the anti-melanogenic effects of resveratryl triglycolate (RTG), a novel hybrid compound of resveratrol and GA, in comparison with resveratrol, GA, resveratryl triacetate (RTA) and arbutin. Resveratrol, RTG, and RTA inhibited the catalytic activity human tyrosinase (TYR) more potently than arbutin or GA did. Their cytotoxic and anti-melanogenic effects were examined using murine melanoma B16/F10 cells and human epidermal melanocytes (HEMs). The cytotoxicity of RTG was similar to that of resveratrol and RTA. RTG at 3-10 µM decreased melanin levels and cellular TYR activities in α-melanocyte-stimulating hormone-stimulated B16/F10 cells, and L-tyrosine-stimulated HEMs. RTG also suppressed mRNA and protein expression of TYR, tyrosinase-related protein 1, L-3,4-dihydroxyphenylalanine chrome tautomerase, and microphthalmia-associated transcription factor (MITF) in HEMs stimulated with L-tyrosine. This study suggests that, like resveratrol and RTA, RTG can attenuate cellular melanin synthesis effectively through the suppression of MITF-dependent expression of melanogenic enzymes and the inhibition of catalytic activity of TYR enzyme. RTG therefore has potential for use as a cosmeceutical ingredient for skin whitening.

A New Neolignan from Coix lachryma-jobi var. mayuen.

A new neolignan, named coixide A (1), along with fifteen known compounds, (7R,8S)-3'-demethyl-dehydrodiconiferyl alcohol-3'-O-ß-glucopyranoside (2), (7R,8)-3'-demethyl-9'-butoxy-dehydrodiconiferyl-3'-O-ß-glucopyranoside (3),adenosine (4), 2-O-caffeoyl isocitricacid (5), pseudolaroside A (6), 2-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (7), 2-O-ß-glucopyranosyl-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (8), 2-O-ß-glucopyranosyl-4-hydroxy-7- methoxy-2H-1,4-benzoxazin-3(4H)-one (9), 2-O-ß-D-glucopyranosyl-7-hydroxy-2H-1,4-benzoxazin-3(4H)-one (10), p-coumaric acid ethyl ester (11), caffeic acid ethyl ester (12), p-coumaric acid (13), cis-N-p-coumaroyltyramine (14) trans-N-p-coumaroyltyramine (15), and coixol (16) have been isolated from Coix lachryma-jobi var. mayuen. Their chemical structures were elucidated by chemical evidence on the basis of spectroscopic and MS data, and as well as by comparison with those reported.

10-Gingerol inhibits proliferation and invasion of MDA-MB-231 breast cancer cells through suppression of Akt and p38MAPK activity.

In the present study, we investigated the roles and molecular mechanism of 10-gingerol, a phenolic compound isolated from Zingiber officinale, in regulating cell proliferation and invasion of MDA­MB­231 breast cancer cells. 10-gingerol treatment inhibited cell proliferation through downregulation of cell cycle regulatory proteins such as cyclin-dependent kinases and cyclins, and subsequent induction of G1 phase arrest. In addition, 10­gingerol treatment blocked cell invasion in response to mitogenic stimulation. These antitumor activities of 10­gingerol were mediated through inactivation of Akt and p38MAPK activity, and suppression of epidermal growth factor receptor expression. Collectively, these findings demonstrate the pharmacological roles of 10-gingerol in regulating breast cancer cell growth and progression, and suggest further evaluation and development as a potential therapeutic agent for the prevention and treatment of breast cancer.

2,8-Decadiene-1,10-Diol Inhibits Lipopolysaccharide-Induced Inflammatory Responses Through Inactivation of Mitogen-Activated Protein Kinase and Nuclear Factor-κB Signaling Pathway.

Amomum tsao-ko (A. tsao-ko) has been used as a traditional medicine for the treatment of infectious and digestive disorders. In the present study, we report the anti-inflammatory activity and molecular mechanism of 2,8-decadiene-1,10-diol (DDO) isolated from the extract of A. tsao-ko in lipopolysaccharide-stimulated RAW 264.7 cells. DDO treatment inhibited the production of nitric oxide and prostaglandin E2 by downregulating inducible nitric oxide synthase and cyclooxygenase-2 expression, respectively. Moreover, DDO suppressed the production of pro-inflammatory cytokines such as interleukin-6 and tumor necrosis factor-α. These inhibitory effects of DDO on the expression of inflammatory proteins were found to be mediated through the inactivation of mitogen-activated protein kinases (MAPKs) such as extracellular signal-regulated kinase, c-Jun-N-terminal kinase and p38(MAPK), and inhibition of nuclear factor-κB (NF-κB) pathways including degradation of inhibitor of κB-α and nuclear localization of NF-κB. Taken together, these findings demonstrate the pharmacological roles and molecular mechanisms of DDO in regulating inflammatory responses, and suggest further evaluation and development of DDO as a potent therapeutic agent for the treatment of inflammatory disorders.

Neolignan inhibitors of antigen-induced degranulation in RBL-2H3 cells from the needles of Pinus thunbergii.

The ethanolic extract of the needles of Pinus thunbergii was found to suppress antigen mediated degranulation of rat basophilic leukemia (RBL-2H3) cells. A new neolignan glycoside, named pinusthunbergiside A (1), as well as six known neolignan glycosides (2-7) were isolated from the ethanolic extract using bioassay-guided fractionation. Their structures were elucidated by a combination of 1D and 2D NMR, HRESI-MS, and circular dichroism (CD) data. Compounds 2-7 were found for the first time in this plant. The inhibitory effects of isolated constituents on the release of ß-hexosaminidase from RBL-2H3 cells were examined, and compounds 2, 3, 5, and 6 were found to show the inhibitory activity with IC50 values ranging between 52.3 and 75.3 µM.

Regulation of microglia activity by glaucocalyxin-A: attenuation of lipopolysaccharide-stimulated neuroinflammation through NF-κB and p38 MAPK signaling pathways.

Microglial cells are the resident macrophages and intrinsic arm of the central nervous system innate immune defense. Microglial cells become activated in response to injury, infection, environmental toxins, and other stimuli that threaten neuronal survival. Therefore, regulating microglial activation may have therapeutic benefits that lead to alleviating the progression of inflammatory-mediated neurodegeneration. In the present study, we investigated the effect of glaucocalyxin A (GLA) isolated from Rabdosia japonica on the production of pro-inflammatory mediators in lipopolysaccharide (LPS)-stimulated primary microglia and BV-2 cells. GLA significantly inhibited LPS-induced production of nitric oxide and reversed the morphological changes in primary microglia. Further, GLA suppressed expression of inducible nitric oxide synthase and cyclooxygenase-2 dose-dependently at the mRNA and protein levels. The production of proinflammatory cytokines such as tumor necrosis factor-α, interleukin-1ß (IL)-1ß, and IL-6 were inhibited by suppressing their transcriptional activity. Furthermore, GLA suppressed nuclear factor-κB activation by blocking degradation of IκB-α and inhibited the induction of lipocalin-2 expression in LPS-stimulated BV-2 cells. Mechanistic study revealed that the inhibitory effects of GLA were accompanied by blocking the p38 mitogen activated protein kinase signaling pathway in activated microglia. In conclusion, given that microglial activation contributes to the pathogenesis of neurodegenerative diseases, GLA could be developed as a potential therapeutic agent for treating microglia-mediated neuroinflammatory diseases.

Morusinol extracted from Morus alba inhibits arterial thrombosis and modulates platelet activation for the treatment of cardiovascular disease.

UNLABELLED: Morus alba (white mulberry) has been used in traditional Chinese medicine as an anti-headache, diuretic, expectorant, and anti-diabetic agent. In previous studies, extracts of Morus alba demonstrated favorable biological properties, such as antioxidant activity, suppression of lipoxygenase (LOX)-1, cytotoxicity against cancer cells, and inhibition of the invasion and migration of cancer cells. AIM: This study further evaluated the effects of morusinol, a flavonoid derived from Morus alba root bark, on platelet aggregation and thromboxane B(2) (TXB(2) formation in vitro and thrombus formation in vivo. METHODS: The antiplatelet potential of morusinol was measured using in vitro rabbit platelet aggregation and TXB(2) formation assays. Arterial thrombus formation was investigated using an in vivo ferric chloride (FeCl(3)-induced thrombosis model. RESULTS: Morusinol significantly inhibited collagen- and arachidonic acid-induced platelet aggregation and TXB(2) formation in cultured platelets in a concentration-dependent manner. Thrombus formation was reduced by 32.1, 42.0, and 99.0% for collagen-induced TXB(2) formation, and 8.0, 24.1, and 29.2% for arachadonic acid-induced TXB(2) formation, with 5, 10, and 30 µg/mL morusinol, respectively. Moreover, oral morusinol (20 mg/kg) or aspirin (20 mg/kg) for three days significantly increased the time to occlusion in vivo by 20.3±5.0 or 6.8±2.9 min, respectively, compared with the control (1% CMC, carboxymethyl cellulose). CONCLUSION: Taken together, these results indicate that morusinol may significantly inhibit arterial thrombosis in vivo due to antiplatelet activity. Thus, morusinol may exert beneficial effects on transient ischemic attacks or stroke via the modulation of platelet activation.