Andrographolide Inhibits Expression of NLPR3 Inflammasome in Canine Mononuclear Leukocytes.

Inflammasomes are multiprotein complexes that trigger processes through caspase-1 activation, leading to the maturation of proinflammatory cytokines, such as IL-1ß and IL-18. The gene encoding the inflammasome stimulatory protein NLRP3 is conserved in canines. Caspase-1/4 homologues have been identified in multiple carnivores, including canines, and caspase-1 activity has been shown in humans. The NLRP3 inflammasome has also been described in some canine inflammatory diseases. Andrographolide, a labdane diterpene, is the principal active ingredient in the herb Andrographis paniculate. The objective of this study was to determine the effect of andrographolide on the gene expression of the components of the NLRP3 inflammasome, proinflammatory cytokines, and IL-1ß secretion in canine peripheral blood mononuclear cells. For this, MTT assays and real-time PCR were employed to assess the cytotoxicity and gene expression. Further, an ELISA test was performed to measure the IL-1ß concentration. The findings reveal that andrographolide significantly reduces the expression of NLRP3, caspase-1/4, IL-1ß, and IL-18. Additionally, it decreases the secretion of IL-1ß and other proinflammatory cytokines, including IL-6, IL-8, and TNF-α. The results show that andrographolide decreases the expression of NLRP3, caspase-1/4, IL-1ß, and IL-18. Andrographolide also reduces proinflammatory cytokines expression, and decreases IL-1ß secretion. This indicates that andrographolide can interfere with the activation and function of the inflammasome, resulting in a decrease in the inflammatory response in canines. Research in this area is still budding, and more studies are necessary to fully understand andrographolide's mechanisms of action and its therapeutic potential in relation to the NLRP3 inflammasome in dogs.

An exploratory double-blind, randomized, placebo-controlled study to assess the efficacy of CitruSlim on body composition and lipid parameters in obese individuals.

The prevalence of obesity in developing and developed countries has been well recognized, and the worldwide obesity rates have nearly tripled since 1975, according to the World Health Organization. CitruSlim, a standardized product containing a blend of Citrus bergamia and Eurycoma longifolia, can reduce cortisol, cholesterol, triglycerides, and hyperglycemia. These properties can contribute to reduction in body weight or body mass index (BMI) in obese patients. A randomized, double-blind, placebo-controlled clinical study was designed to evaluate the efficacy and tolerability of CitruSlim in body weight management in obese individuals, and the results were compared with that of placebo. A total of 97 participants were allocated, randomized, and treated with CitruSlim high-dose (HD, 400 mg), CitruSlim low-dose (LD, 200 mg), and placebo for 112 days. At the end of the study, CitruSlim HD and CitruSlim LD significantly reduced BMI compared to the placebo group and were well tolerated; however, it did not improve parameters associated with dyslipidemia and metabolic disturbances. The study findings suggested that CitruSlim was effective in reducing body weight in obese patients.

Andrographolide, an Anti-Inflammatory Multitarget Drug: All Roads Lead to Cellular Metabolism.

Andrographolide is a labdane diterpene and the main active ingredient isolated from the herb Andrographis paniculata. Andrographolide possesses diverse biological effects including anti-inflammatory, antioxidant, and antineoplastic properties. Clinical studies have demonstrated that andrographolide could be useful in therapy for a wide range of diseases such as osteoarthritis, upper respiratory diseases, and multiple sclerosis. Several targets are described for andrographolide, including the interference of transcription factors NF-κB, AP-1, and HIF-1 and signaling pathways such as PI3K/Akt, MAPK, and JAK/STAT. In addition, an increase in the Nrf2 (nuclear factor erythroid 2-related factor 2) signaling pathway also supports its antioxidant and anti-inflammatory properties. However, this scenario could be more complex since recent evidence suggests that andrographolide targets can modulate glucose metabolism. The metabolic effect of andrographolide might be the key to explaining the diverse therapeutic effects described in preclinical and clinical studies. This review discusses some of the most recent evidence about the anti-inflammatory and metabolic effects of andrographolide.

Efficacy of andrographolide in not active progressive multiple sclerosis: a prospective exploratory double-blind, parallel-group, randomized, placebo-controlled trial.

BACKGROUND: Multiple sclerosis (MS) is a chronic immune mediated disease and the progressive phase appears to have significant neurodegenerative mechanisms. The classification of the course of progressive MS (PMS) has been re-organized into categories of active vs. not active inflammatory disease and the presence vs. absence of gradual disease progression. Clinical trial experience to date in PMS with anti-inflammatory medications has shown limited effect. Andrographolide is a new class of anti-inflammatory agent, that has been proposed as a potential drug for autoimmune disorders, including MS. In the present trial, we perform an exploratory pilot study on the efficacy and safety of andrographolide (AP) compared to placebo in not active PMS. METHODS: A pilot clinical trial using 140 mg oral AP or placebo twice daily for 24 months in patients with not active primary or secondary progressive MS was conducted. The primary efficacy endpoint was the mean percentage brain volume change (mPBVC). Secondary efficacy endpoints included 3-month confirmed disability progression (3-CDP) and mean EDSS change. RESULTS: Forty-four patients were randomized: 23 were assigned to the AP group, and 21 were assigned to the placebo group. The median baseline EDSS of both groups was 6.0. Annualized mPBVC was - 0.679% for the AP group and - 1.069% for the placebo group (mean difference: -0.39; 95% CI [- 0.836-0.055], p = 0.08, relative reduction: 36.5%). In the AP group, 30% had 3-CDP compared to 41% in the placebo group (HR: 0.596; 95% CI [0.200-1.777], p = 0.06). The mean EDSS change was - 0.025 in the AP group and + 0.352 in the placebo group (mean difference: 0.63, p = 0.042). Adverse events related to AP were mild rash and dysgeusia. CONCLUSIONS: AP was well tolerated and showed a potential effect in reducing brain atrophy and disability progression, that need to be further evaluated in a larger clinical trial. TRIAL REGISTRATION: ClinicalTrials.gov NCT02273635 retrospectively registered on October 24th, 2014.

Andrographolide activates the canonical Wnt signalling pathway by a mechanism that implicates the non-ATP competitive inhibition of GSK-3ß: autoregulation of GSK-3ß in vivo.

Wnt/ß-catenin signalling is an important pathway that regulates multiple biological processes, including cell adhesion and determination of cell fate during animal development; in the adult nervous system it regulates the structure and function of synapses. Wnt-signalling dysfunction is associated with several neurodegenerative diseases such as schizophrenia and Alzheimer's disease. The use of natural compounds is an interesting strategy in the search for drugs with the therapeutic potential to activate this signalling pathway. In the present study, we report that andrographolide (ANDRO), a component of Andrographis paniculata, is a potent activator of Wnt signalling. Our results indicate that ANDRO activates this pathway, inducing the transcription of Wnt target genes by a mechanism that bypasses Wnt ligand binding to its receptor. In vitro kinase assays demonstrate that ANDRO inhibits glycogen synthase kinase (GSK)-3ß by a non-ATP-competitive, substrate-competitive mode of action. In silico analyses suggest that ANDRO interacts with the substrate-binding site of GSK-3ß. Finally, we demonstrated that the increase seen in the levels of GSK-3ß phosphorylated at Ser9 is the result of an autoregulatory mechanism of the kinase in vivo, although not through activation of protein phosphatase type 1. Our results suggest that ANDRO could be used as a potential therapeutic drug for disorders caused by Wnt-signalling dysfunction such as neurodegenerative diseases.

Andrographolide Stimulates Neurogenesis in the Adult Hippocampus.

Andrographolide (ANDRO) is a labdane diterpenoid component of Andrographis paniculata widely used for its anti-inflammatory properties. We have recently determined that ANDRO is a competitive inhibitor of glycogen synthase kinase-3ß (GSK-3ß), a key enzyme of the Wnt/ß-catenin signaling cascade. Since this signaling pathway regulates neurogenesis in the adult hippocampus, we evaluated whether ANDRO stimulates this process. Treatment with ANDRO increased neural progenitor cell proliferation and the number of immature neurons in the hippocampus of 2- and 10-month-old mice compared to age-matched control mice. Moreover, ANDRO stimulated neurogenesis increasing the number of newborn dentate granule neurons. Also, the effect of ANDRO was evaluated in the APPswe/PS1ΔE9 transgenic mouse model of Alzheimer's disease. In these mice, ANDRO increased cell proliferation and the density of immature neurons in the dentate gyrus. Concomitantly with the increase in neurogenesis, ANDRO induced the activation of the Wnt signaling pathway in the hippocampus of wild-type and APPswe/PS1ΔE9 mice determined by increased levels of ß-catenin, the inactive form of GSK-3ß, and NeuroD1, a Wnt target gene involved in neurogenesis. Our findings indicate that ANDRO stimulates neurogenesis in the adult hippocampus suggesting that this drug could be used as a therapy in diseases in which neurogenesis is affected.

Andrographolide reduces cognitive impairment in young and mature AßPPswe/PS-1 mice.

Alzheimer's disease (AD) is a neurodegenerative disorder in which the amyloid-ß (Aß) oligomers are a key factor in synaptic impairment and in spatial memory decline associated with neuronal dysfunction. This impairment includes synaptic failure associated with the loss of synaptic proteins that contribute to AD progression. Interestingly, the use of natural compounds is an emergent conceptual strategy in the search for drugs with therapeutic potentials for treating neurodegenerative disorders. In the present study, we report that andrographolide (ANDRO), which is a labdane diterpene extracted from Andrographis paniculata, increases slope of field excitatory postsynaptic potentials (fEPSP) in the CA1 region of hippocampal slices and inhibits long-term depression (LTD), protecting the long-term potentiation (LTP) against the damage induced by Aß oligomers in vitro, most likely by inhibiting glycogen synthase kinase-3ß (GSK-3ß). Additionally, ANDRO prevents changes in neuropathology in two different age groups (7- and 12-month-old mice) of an AßPPswe/PS-1 Alzheimer's model. ANDRO reduces the Aß levels, changing the ontogeny of amyloid plaques in hippocampi and cortices in 7-month-old mice, and reduces tau phosphorylation around the Aß oligomeric species in both age groups. Additionally, we observed that ANDRO recovers spatial memory functions that correlate with protecting synaptic plasticity and synaptic proteins in two different age groups. Our results suggest that ANDRO could be used in a potential preventive therapy during AD progression.

Delphinidin activates NFAT and induces IL-2 production through SOCE in T cells.

Delphinidin is an anthocyanidin that possesses antioxidant and anti-inflammatory effects; however, some reports suggest that delphinidin has pro-inflammatory properties. For this reason, we assessed the effect of delphinidin on cytokine production in T cells. We demonstrated that delphinidin increased the cytosolic-free Ca(2+) concentration by releasing Ca(2+) from intracellular stores and increasing Ca(2+) entry. The putative Ca(2+) release activated Ca(2+) (CRAC) channel inhibitors BTP2 and gadolinium reduced the calcium entry stimulated by the anthocyanidin. Delphinidin induced nuclear factor of activated T cells (NFAT) translocation and NFAT-Luc activity in Jurkat cells and was dependent on the CRAC channel and calcineurin pathway. Delphinidin increased the mRNA expression and production of IL-2 in Jurkat cells and was inhibited by BTP2 and cyclosporine A. Using peripheral blood lymphocytes, we demonstrated that delphinidin increased the production of IL-2 and IFN-γ and was inhibited by BTP2. Taken together, our results suggest that delphinidin exerts immunostimulatory effects on T cells by increasing cytokine production through CRAC channel and NFAT activation.

Hypoglycemic effect of lupin seed γ-conglutin in experimental animals and healthy human subjects.

A lupin seed γ-conglutin-enriched preparation was tested in a glucose overload trial with both murine models and adult healthy volunteers. The results with rats showed a dose-dependent significant decrease of blood glucose concentration, which confirmed previous findings obtained with the purified protein. Moreover, three test-product doses equivalent to 630, 315, and 157.5 mg γ-conglutin, orally administered 30 min before the carbohydrate supply, showed a relevant hypoglycemic effect in human trials. Insulin concentrations were not significantly affected. The general hematic parameters did not change at all. This is the first report on the glucose-lowering effect of lupin γ-conglutin in human subjects.

Effects of Aristotelia chilensis berry juice on cyclooxygenase 2 expression, NF-kB, NFAT, ERK1/2 and PI3K/Akt activation in colon cancer cells / Efecto de un concentrado del fruto de Aristotelia chilensis sobre la expresión de cicloxigenasa 2, NF-kB, NFAT, ERK1/2 y activación de PI3K/Akt en células de cancer de colon

Aristotelia chilensis is a native berry from southern Chile with a high content of anthocyanins, compounds that exhibit antioxidant and anti-inflammatory properties. In the present study, we evaluated the effects of A. chilensis berry juice on cyclooxygenase (COX)-2 expression, intracellular signaling pathways, and cell viability in colon cancer cells. The treatment of Caco-2 cells with A. chilensis diluted juice for 24 h reduced the protein and mRNA expression of COX-2, as well as the TNF-Ą-induced NF-kB luciferase activity and NFAT activation. In contrast, 4 h after administration, A. chilensis transiently reduced the cytoplasmic IkBa levels and increased ERK1/2 and Akt phosphorylation as well as c-fos expression. At concentrations that reduced COX-2 expression, A. chilensis did not affected Caco-2 cell viability. Our results suggest a potential anti-carcinogenic and anti-inflammatory effect of A. chilensis.

Aristotelia chilensis es un berrie originario del sur de Chile, que posee un alto contenido de antocianinas, compuestos con propiedades antioxidantes y anti-inflamatorias. En este estudio, se evaluó los efectos de un concentrado de A. chilensis sobre expresión de ciclooxigenasa (COX)-2, vías de señalización y viabilidad en células de cáncer de colon. El tratamiento de células Caco-2 con A. chilensis por 24 h redujo la expresión de la proteína y mRNA de COX-2, y disminuyó la actividad luciferasa regulada por NF-kB o NFAT. El tratamiento de células Caco-2 por 4 h con A. chilensis redujo transitoriamente los niveles citoplasmáticos de IkBa, aumentó la fosforilación de ERK1/2 y Akt y la expresión de c-fos. A. chilensis no afectó la viabilidad celular, a concentraciones que redujo la expresión de COX-2. Los resultados sugieren un potencial efecto anticancerígeno y antiinflamatorio de A. chilensis.

Andrographolide reduces IL-2 production in T-cells by interfering with NFAT and MAPK activation.

The nuclear factor of activated T cells (NFAT) is a transcription factor essential for cytokine production during T-cell activation and is the target of several immunosuppressive drugs. Andrographolide is a diterpenic labdane that possesses anti-inflammatory and immunomodulatory effects. Several studies propose that andrographolide can reduce the immune response through inhibition of the nuclear factor kappa B (NF-kappaB) and mitogen-activated protein kinases (MAPK) such as extracellular signal regulated kinase 1/2 (ERK1/2) pathways. Moreover, andrographolide reduces IFN-gamma and IL-2 production induced by concanavalin A in murine T-cell. Nevertheless, the mechanisms involved in the decrease of cytokine production are unknown. In the present study, we determined that andrographolide reduced IL-2 production in Jurkat cells stimulated with phorbol myristate acetate and ionomycin (PMA/Ionomycin). We then showed that andrographolide reduced NFAT luciferase activity and interfered with its nuclear distribution, with these effects being linked to an increase in c-jun-N-terminal kinase (JNK) phosphorylation. Additionally, reduction of NF-kappaB activity in Jurkat cells treated with andrographolide was observed. Using Western blotting, we demonstrated that andrographolide decreased ERK1 and ERK5 phosphorylation induced by anti-CD3 or PMA/Ionomycin. Andrographolide did not affect cell viability at concentration of 10 and 50 muM; however, our results suggest that andrographolide increase early apoptosis at 100 muM. We concluded that andrographolide can exert immunomodulatory effects by interfering with NFAT activation and ERK1 and ERK5 phosphorylation in T-cells.

Release of acetylcholinesterase (AChE) from beta-amyloid plaques assemblies improves the spatial memory impairments in APP-transgenic mice.

The major protein constituent of amyloid deposits in Alzheimer's disease (AD) is the amyloid-beta-peptide (Abeta). Amyloid deposits contain "chaperone molecules" which play critical roles in amyloid formation and toxicity. In the present work, we test an analog of hyperforin (IDN 5706) which releases the AChE from both the Abeta fibrils and the AChE-Abeta burdens in transgenic mice. Hyperforin is an acylphloroglucinol compound isolated from Hypericum perforatum (St. John's Wort), which is able to prevent the Abeta-induced spatial memory impairments and Abeta neurotoxicity. Altogether this gathered evidence indicates the important role of AChE in the neurotoxicity of Abeta plaques and finding new compounds which decrease the AChE-Abeta interaction may be a putative therapeutic agent to fight the disease.

Store-operated calcium entry mediates intracellular alkalinization, ERK1/2, and Akt/PKB phosphorylation in bovine neutrophils.

Neutrophil's responses to G protein-coupled chemoattractants are highly dependent on store-operated calcium (Ca(2+)) entry (SOCE). Platelet-activating factor (PAF), a primary chemoattractant, simultaneously increases cytosolic-free Ca(2+), intracellular pH (pH(i)), ERK1/2, and Akt/protein kinase B (PKB) phosphorylation. In this study, we looked at the efficacy of several putative SOCE inhibitors and whether SOCE mediates intracellular alkalinization, ERK1/2, and Akt/PKB phosphorylation in bovine neutrophils. We demonstrated that the absence of external Ca(2+) and the presence of EGTA reduced the intracellular alkalinization and ERK1/2 phosphorylation induced by PAF, apparently via SOCE influx inhibition. Next, we tested the efficacy of several putative SOCE inhibitors such as 2-aminoethoxydiphenyl borate (2-APB), capsaicin, flufenamic acid, 1-{beta-[3-(4-methoxy-phenyl)propoxy]-4-methoxyphenethyl}-1H-imidazole hydrochloride (SK&F 96365), and N-(4-[3,5-bis(trifluoromethyl)-1H-pyrazol-1-yl]phenyl)-4-methyl-1,2,3-thiadiazole-5-carboxamide (BTP2) on Ca(2+) entry induced by PAF or thapsigargin. 2-APB was the most potent SOCE inhibitor, followed by capsaicin and flufenamic acid. Conversely, SK&F 96365 reduced an intracellular calcium ([Ca(2+)](i)) peak but SOCE partially. BTP2 did not show an inhibitory effect on [Ca(2+)](i) following PAF stimuli. 2-APB strongly reduced the pH(i) recovery, whereas the effect of flufenamic acid and SK&F 96365 was partial. Capsaicin and BTP2 did not affect the pH(i) changes induced by PAF. Finally, we observed that 2-APB reduced the ERK1/2 and Akt phosphorylation completely, whereas the inhibition with flufenamic acid was partial. The results suggest that 2-APB is the most potent SOCE inhibitor and support a key role of SOCE in pH alkalinization and PI-3K-ERK1/2 pathway control. Finally, 2-APB could be an important tool to characterize Ca(2+) signaling in neutrophils.

14-deoxyandrographolide as a platelet activating factor antagonist in bovine neutrophils.

14-Deoxyandrographolide (14-DAP) is a labdane diterpene isolated from Andrographis paniculata with previously reported calcium channel blocking activity. Its potential platelet activating factor (PAF) antagonistic activity in bovine neutrophils was assessed. 14-DAP, in concentrations between 10-100 microM, reduced the extracellular acidification rate and the intracellular alkalinization in a dose-dependent manner. In addition, 14-DAP reduced PAF-induced calcium flux in the presence of extracellular calcium, and tyrosine phosphorylation of a 44 kDa protein corresponding to the MAPK(ERK1). However, 14-DAP reduced the 3H-PAF binding with a Ki of 7.8 x 10 (- 9)M, and a Hill slope of 0.63, suggesting that there is more than one binding site for 14-DAP. We concluded that 14-DAP is an effective antagonist of PAF-mediated processes in bovine neutrophils, probably by virtue of its calcium channel blocking property.

Andrographolide inhibits IFN-gamma and IL-2 cytokine production and protects against cell apoptosis.

Andrographolide is the main labdane diterpene present in Andrographis paniculata. Two lines of evidence report immunostimulant and anti-inflammatory properties for andrographolide in different models. Using murine T-cells in vitro we demonstrated that andrographolide and to a lesser extent, 14-deoxyandrographolide (14-DAP), reduced significantly, in a dose-dependent manner, the IFN-gamma production induced by concanavaline A (CON-A), with an IC50 of 1.7 +/- 0.07 microM and 35.8 +/- 0.50 microM, respectively. Andrographolide, but not 14-DAP, inhibited partially the IL-2 production induced by CON-A. Andrographolide at doses of 5 and 10 microM reduced the extracellular-signal-regulated protein kinase (ERK1/2) phosphorylation induced by CON-A, whereas 14-DAP only reduced ERK1 and partially the ERK2 phosphorylation. The inhibition of ERK1/2 phosphorylation was associated to a decrease in the IFN-gamma production, due that UO126, a specific ERK1/2 inhibitor, also reduced the IFN-gamma production in murine T-cells induced by CON-A. Additionally, andrographolide and to a lesser extent 14-DAP, at doses of 50 microM and 100 microM, respectively, reduced the apoptosis induced by hydrocortisone and PMA in thymocytes, which was associated to a decrease in caspase-3 like activity. We conclude that both diterpenic labdanes isolated from A. paniculata can exert potent immunosuppressant effects without affecting the viability of the cells.

Andrographolide interferes with binding of nuclear factor-kappaB to DNA in HL-60-derived neutrophilic cells.

1. Andrographolide, the major active component from Andrographis paniculata, has shown to possess anti-inflammatory activity. Andrographolide inhibits the expression of several proinflammatory proteins that exhibit a nuclear factor kappa B (NF-kappaB) binding site in their gene. 2. In the present study, we analyzed the effect of andrographolide on the activation of NF-kappaB induced by platelet-activating factor (PAF) and N-formyl-methionyl-leucyl-phenylalanine (fMLP) in HL-60 cells differentiated to neutrophils. 3. PAF (100 nM) and fMLP (100 nM) induced activation of NF-kappaB as determined by degradation of inhibitory factor B alpha (IkappaB alpha) using Western blotting in cytosolic extracts and by binding to DNA using electrophoretic mobility shift assay (EMSA) in nuclear extracts. 4. Andrographolide (5 and 50 microM) inhibited the NF-kappaB-luciferase activity induced by PAF. However, andrographolide did not reduce phosphorylation of p38 MAPK or ERK1/2 and did not change IkappaB alpha degradation induced by PAF and fMLP. 5. Andrographolide reduced the DNA binding of NF-kappaB in whole cells and in nuclear extracts induced by PAF and fMLP. 6. Andrographolide reduced cyclooxygenase-2 (COX-2) expression induced by PAF and fMLP in HL-60/neutrophils. 7. It is concluded that andrographolide exerts its anti-inflammatory effects by inhibiting NF-kappaB binding to DNA, and thus reducing the expression of proinflammatory proteins, such as COX-2.

Andrographolide interferes with T cell activation and reduces experimental autoimmune encephalomyelitis in the mouse.

Andrographolide is a bicyclic diterpenoid lactone derived from extracts of Andrographis paniculata, a plant indigenous to South Asian countries that shows anti-inflammatory properties. The molecular and cellular bases for this immunomodulatory capacity remain unknown. Here, we show that andrographolide is able to down-modulate both humoral and cellular adaptive immune responses. In vitro, this molecule was able to interfere with T cell proliferation and cytokine release in response to allogenic stimulation. These results were consistent with the observation that T cell activation by dendritic cells (DCs) was completely abolished by exposing DCs to andrographolide during antigen pulse. This molecule was able to interfere with maturation of DCs and with their ability to present antigens to T cells. Furthermore, in vivo immune responses such as antibody response to a thymus-dependent antigen and delayed-type hypersensitivity were drastically diminished in mice by andrographolide treatment. Finally, the ability of andrographolide to inhibit T cell activation was applied to interfere with the onset of experimental autoimmune encephalomyelitis (EAE), an inflammatory demyelinating disease of the central nervous system that is primarily mediated by CD4(+) T cells and serves as an animal model for human multiple sclerosis. Treatment with andrographolide was able to significantly reduce EAE symptoms in mice by inhibiting T cell and antibody responses directed to myelin antigens. Our data suggest that andrographolide is able to efficiently block T cell activation in vitro, as well as in vivo, a feature that could be useful for interfering with detrimental T cell responses.

Determination of specific receptor sites for platelet activating factor in bovine neutrophils.

OBJECTIVE: To identify and characterize a platelet activating factor (PAF) receptor in bovine neutrophils by use of radioligand binding, reverse transcription-polymerase chain reaction (RT-PCR) assay, and western blot analysis. ANIMALS: 4 healthy adult cows. PROCEDURE: Bovine neutrophil membranes were isolated for association, dissociation, and saturation binding experiments with PAF labeled with hydrogen 3 (3H-PAF). The RT-PCR assay was performed with appropriate human primers, and western blot analysis was developed with a polyclonal antibody obtained from a peptide of bovine PAF receptor. RESULTS: Analysis of kinetic binding data supported a single class of PAF receptor. Binding of 3H-PAF to membrane preparations was selectively displaced by PAF and a nonhydrolyzable analogue of guanine triphosphate (Gpp[NH]p) and by lyso-PAF (a biologically inactive analogue of PAF) to a lesser extent. Among other PAF receptor antagonists, 14-deoxyandrographolide and WEB 2086 were the most effective in inhibiting 3H-PAF binding sites in neutrophil membranes; 2 lignans, schisandrin-A and gamma-schisandrin were also effective, but 2 gingkolides (BN52020 and BN52021) only mildly inhibited 3H-PAF binding. Results of RT-PCR assay and western blot analysis of neutrophil crude membranes confirmed the presence of a PAF receptor. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that bovine neutrophils express only 1 type of PAF receptor, and it is likely that this receptor is involved in inflammatory responses. The most effective PAF antagonists were 14-deoxyandrographolide and WEB 2086; these PAF antagonists may be potentially useful in the treatment of inflammatory processes in cattle.

Platelet-activating factor increases pH(i) in bovine neutrophils through the PI3K-ERK1/2 pathway.

1. Platelet-activating factor (PAF) is known to stimulate a variety of neutrophil activities, including chemotaxis, phagocytosis, degranulation, reactive oxygen species production and intracellular pH increase. The purpose of this study was to investigate the effect of PAF on pH((i)), specifically if these changes in pH are the result of phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathway activation in bovine neutrophils. 2. PAF caused intracellular alkalinization in 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester-loaded bovine neutrophils. This phenomenon seems to be mediated by amiloride-sensitive Na(+)/H(+) exchange, and is inhibited by WEB2086 (a selective PAF receptor antagonist), genistein (a tyrosine kinase inhibitor), wortmannin and LY294002 (PI3K inhibitors), and PD98059 and UO126 (MEK inhibitors). 3. PAF 100 nm induced an increase in tyrosine phosphorylation of proteins 62, 44 and 21 kDa with a maximum response at 2 min of incubation. 4. Unlike human neutrophils, bovine neutrophils are strongly stimulated by PAF via phosphorylation of ERK1/2 (extracellular-signal-regulated protein kinase) with an EC(50) of 30 and 13 nm, respectively. 5. PAF MAPK activation was also inhibited by WEB2086, pertussis toxin (PTX), genistein, wortmannin, LY294002, PD98059 and UO126 in bovine neutrophils. The ERK1/2 activation is dependent on PI3K pathway, because protein kinase B was phosphorylated by PAF and inhibited by wortmannin and LY294002, but not by U0126. 6. Our results suggest that PAF induces intracellular alkalinization via PI3K-MAPK activation. This effect is upstream regulated by PAF receptor, PTX-sensitive G protein, tyrosine kinase, PI3K and MEK1/2 in bovine neutrophils.

Effect of 14-deoxyandrographolide on calcium-mediated rat uterine smooth muscle contractility.

In this study, the effect of 14-deoxyandrographolide (14-DAP) on calcium channel-dependent rat uterine smooth muscle contraction was evaluated. Using a tissue bath preparation, 14-DAP was able to reduce the contractile response to 0.3 and 3.0 mm of CaCl(2), with an IC(50) of 1.24 +/- 0.23 x 10(-5) m and 5.94 +/- 0.29 x 10(-5) m, respectively. 14-DAP shifted the CaCl(2) cumulative dose response curve to the right, increasing the EC(50) from 2.08 +/- 0.20 x 10(-4) m to 4.22 +/- 0.22 x 10(-4) m (5 micrometer 14-DAP) and 2.5 +/- 1.0 x 10(-3) m (50 micrometer 14-DAP). In order to determine if 14-DAP had any effect on intracellular calcium, the relaxant response to 14-DAP following contraction by oxytocin, PGF(2alpha) and vanadate in Ca(+2)-free solution was compared with that of isoproterenol and phenylbutazone. While isoproterenol and phenylbutazone relaxed the smooth muscle in a dose-dependent manner, 14-DAP did not have any effect on either the oxytocin, PGF(2alpha) or vanadate-induced smooth muscle contraction. Based on these data, it appears that 14-DAP is an uterine smooth muscle relaxant which produces a selective blockade of voltage operated calcium channels.