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.

Phytochemical investigation on the aerial parts of Veratrum versicolor f. viride Nakai and their biological activities.

Veratrum spp. have traditionally been used in folk medicine to treat various pathologies. In this study, nine compounds, comprising one simple phenolic compound (1), three stilbenoids (2-4), and five flavonoids (5-9), were isolated from the aerial parts of Veratrum versicolor f. viride Nakai. The structures of these compounds were elucidated by spectroscopic analyses and comparison with reported data. Together, all reported compounds were isolated from V. versicolor f. viride for the first time in the study. Among them, two flavone aglycone tricetins (7 and 9) have never been isolated from the genus Veratrum or the family Melanthiaceae. The ethanol extract and isolated compounds were assessed for their inhibitory effects on elastase, tyrosinase, and melanin synthesis. Compounds 5 and 7 inhibited elastase (IC50: 292.25 ± 14.39 and 800.41 ± 5.86 µM, respectively), whereas compounds 2-5 inhibited tyrosinase with IC50 values in the range of 6.42 ~ 51.19 µM, respectively. In addition, compounds 3-6 and 8 exhibited dose-dependent inhibition (70.4% ~ 91.0%) of melanogenesis at a concentration of 100 µM.

Identification of p-Coumaric Acid and Ethyl p-Coumarate as the Main Phenolic Components of Hemp (Cannabis sativa L.) Roots.

Hemp (Cannabis sativa L.) contains a variety of secondary metabolites, including cannabinoids, such as psychoactive (-)-trans-Δ9-tetrahydrocannabinol. The present study was conducted to identify the major phenolic components contained in hemp root, which has been relatively under-researched compared to other parts of hemp. The aqueous ethanol extract of hemp roots was fractionated into methylene chloride (MC), ethyl acetate (EA), and water (WT) fractions, and high-performance liquid chromatography with photodiode array detection (HPLC-DAD) analysis was performed. The main ultraviolet (UV)-absorbing phenolic compound contained in the EA fraction was identified as p-coumaric acid by comparing the retention time and UV absorption spectrum with a standard. Silica gel column chromatography was performed to isolate a hydrophobic derivative of p-coumaric acid contained in the MC fraction. Nuclear magnetic resonance (NMR) analysis identified the isolated compound as ethyl p-coumarate. For comparative purposes, ethyl p-coumarate was also chemically synthesized by the esterification reaction of p-coumaric acid. The content of p-coumaric acid and ethyl p-coumarate in the total extract of hemp root was estimated to be 2.61 mg g-1 and 6.47 mg g-1, respectively, by HPLC-DAD analysis. These values correspond to 84 mg Kg-1 dry root and 216 mg Kg-1 dry root, respectively. In conclusion, this study identified p-coumaric acid and ethyl p-coumarate as the main phenolic compounds contained in the hemp roots.

Lotus Seed Green Embryo Extract and a Purified Glycosyloxyflavone Constituent, Narcissoside, Activate TRPV1 Channels in Dorsal Root Ganglion Sensory Neurons.

Several studies have documented the broad-spectrum bioactivities of a lotus seed (Plumula nelumbinis [PN]) green embryo extract. However, the specific bioactive components and associated molecular mechanisms remain largely unknown. This study aimed to identify the ion channel-activating mechanisms of PN extracts. Using fluorometric imaging and patch-clamp recordings, PN extracts were screened for calcium channel activation in dorsal root ganglion (DRG) neurons. The TRPV1 channels in DRG neurons were strongly activated by the PN extract (mean amplitude of 131 ± 45 pA at 200 µg/mL) and its purified glycosyloxyflavone narcissoside (401 ± 271 pA at 100 µM). Serial treatment with a 200 µg/mL PN extract in TRPV1-overexpressing HEK293T cells induced robust desensitization to 10 ± 10% of the initial current amplitude. Thus, we propose that the PN extract and narcissoside function as TRPV1 agonists. This new finding may advance our knowledge regarding the traditional and scientific functions of PN in human health and disease.

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.

Monoterpenoids from the Fruits of Amomum tsao-ko Have Inhibitory Effects on Nitric Oxide Production.

In our search for novel plant-derived inhibitors of nitric oxide (NO) with potential for treating inflammatory diseases, the phytochemicals of Amomum tsao-ko fruits were investigated, leading to the isolation of one bicyclic nonane (1), three menthene skeleton monoterpenoids (2-4), and two acyclic monoterpenoids (5 and 6). Their structures were identified using one- and two-dimensional nuclear magnetic resonance spectroscopy, and mass spectrometry. To the best of our knowledge, compounds 2-5 were obtained from the genus Amomum for the first time. All isolates were tested for their ability to inhibit lipopolysaccharide-stimulated NO overproduction in RAW264.7 cells. Compound 4 was found to inhibit NO production. Western blotting analysis indicated that active compound 4 can regulate inducible NO synthase expression. In addition, lipopolysaccharide-induced interleukin 1 beta and interleukin-6 overproduction was reduced in a concentration-dependent manner.

Diterpenoids and phenolic analogues from the roots of Aralia continentalis.

Two new compounds, including a nor-pimarane diterpenoid (continentanol, 1) and a phenolic derivative (aralianic acid, 2), along with the known diterpenoids (3-11), polyacetylenes (12-15), phenolic components (16-28), and phytosterols (29 and 30), were isolated from roots of Aralia continentalis. The structures of the new compounds were established by spectroscopic data interpretation, particularly HRESIMS, 1 D and 2 D NMR data including HSQC and HMBC. Also, those of the known compounds were identified by spectral comparison with those of the reported values.[Formula: see text].

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.

Combretum quadrangulare Extract Attenuates Atopic Dermatitis-Like Skin Lesions through Modulation of MAPK Signaling in BALB/c Mice.

Atopic dermatitis (AD) is a chronic inflammatory disease. Combretum quadrangulare (C. quadrangulare) is used as a traditional medicine to improve various pathologies in Southeast Asia. In this study, we investigated the effects of C. quadrangulare ethanol extract (CQ) on 1-chloro-2,4-dinitrobenzene (DNCB)-induced AD like skin lesions in BALB/c mice. After administration with CQ (100, 200, and 400 mg/kg) for 6 weeks, AD symptoms, protein expression, immunoglobulin E (IgE), thymus and activation-regulated chemokine (TARC), and ceramidase level were measured in skin lesions of DNCB-induced BALB/c mice. CQ group improved the dermatitis score, skin pH, transepidermal water loss (TEWL), and skin hydration. Furthermore, histological analysis revealed that CQ attenuated the increased epidermal thickness and infiltration of mast cells caused by DNCB. CQ also increased the expression of filaggrin, and reduced the expression of ceramidase, serum IgE level, and the number of eosinophils. CQ effectively inhibited cytokines and chemokines such as interleukin (IL)-6, IL-13, TARC, and thymic stromal lymphopoietin (TSLP) at the mRNA levels, as well as the activation of mitogen-activated protein kinase (MAPK), including extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38 in the skin lesions. Taken together, these findings demonstrate that CQ may be an effective treatment of AD-like skin lesions by inhibiting the expression of inflammatory mediators via the MAPK signaling pathways.

Skin-Related Properties and Constituents from the Aerial Parts Extract of Persicaria senticosa.

In the course of screening for cosmetic ingredients by measuring antioxidant and antiwrinkle and whitening and anti-inflammatory activities, skin-related activity was tested using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, elastase inhibition, tyrosinase inhibition, and nitric oxide assay. Several Polygonaseae extracts were found to show potent activity. The results showed that the Persicaria senticosa methanolic extract has the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ABTS radical scavenging activities (IC50 61.0 and 17.5 µg/mL). In the elastase inhibition assay and nitric oxide assay, the IC50 of methanolic extract of Persicaria senticosa was 739.7 µg/mL and 71.8 µg/mL. The Persicaria senticosa 70% ethanolic extract partitioned with n-hexane, CH2Cl2, EtOAc, n-BuOH, and aqueous fractions. The purification of EtOAc soluble layer was by column chromatography separation and MPLC analysis of Compounds 1-7. It was identified as loliolide (1), quercetin-3-O-glucoside (2), quercetin-3-O-glucuronide (3), 4-methoxy caftraric acid (4), kaempferol-3-(6-methylglucuronide) (5), quercetin-3-(6-methylglucuronide) (6), and quercetin (7). Structure was elucidated by a combination of 1D and 2D NMR and MS spectrometry as well as comparison with reported literatures. Radical scavenging effect on DPPH, tyrosinase inhibition, and nitric oxide assay on several compounds from Persicaria senticosa was found to show potent activity. The results showed that Compound 7 has the NO assay (IC5029.7 µM). For DPPH, the IC50 of Compounds 2, 3, 5, and 7 was 39.6, 31.2, 37.0, and 22.7 µM. In tyrosinase inhibitory activity, the IC50 of Compound 7 was 14.3 µM.

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.

Coixlachryside B: a new benzoxazinoid glycoside from the roots of Coix lachryma-jobi var. ma-yuen (Gramineae).

Coix lachryma-jobi L. var. ma-yuen has been a source of food and traditional folk medicine in some parts of Asia for thousands of years; however, the roots of this plant have not been phytochemically investigated. Herein, we report the isolation of a new benzoxazinoid glycoside, coixlachryside B (1), along with ten known compounds (2-11), from the roots of C. lachryma-jobi var. ma-yuen using a variety of chromatographic methods. Among the known compounds, the absolute configuration of compound 4 was determined. The structures of all compounds were elucidated by interpreting NMR spectroscopic data, and experimental and calculated electronic circular dichroism spectra.

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.

Salvia plebeia Extract Inhibits Xanthine Oxidase Activity In Vitro and Reduces Serum Uric Acid in an Animal Model of Hyperuricemia.

Hyperuricemia is a clinical condition characterized by an elevated level of serum uric acid and is a key risk factor for the development of gout and metabolic disorders. The existing urate-lowering therapies are often impractical for certain patient populations, providing a rationale to explore new agents with improved safety and efficacy. Here, we discovered that Salvia plebeia extract inhibited the enzyme activity of xanthine oxidase, which is a key enzyme generating uric acid in the liver. In an animal model of hyperuricemia, S. plebeia extract reduced serum urate to the levels observed in control animals. The urate-lowering effect of S. plebeia extract in vivo was supported by the identification of compounds that inhibit xanthine oxidase enzyme activity in vitro. Nepetin, scutellarein, and luteolin contributed significantly to S. plebeia bioactivity in vitro. These compounds showed the highest potency against xanthine oxidase with IC50 values of 2.35, 1.74, and 1.90 µM, respectively, and were present at moderate quantities. These observations serve as a basis for further elaboration of the S. plebeia extracts for the development of new therapeutics for hyperuricemia and related diseases.