Antiarthritic effect of bee venom: Inhibition of inflammation mediator generation by suppression of NF-?B through interaction with the p50 subunit

Anti-inflammatory and arthritic effects of thiacremonone, a novel sulfur compound isolated from garlic via inhibition of NF-kappaB

INTRODUCTION

Sulfur compounds isolated from garlic exert anti-inflammatory properties. We recently isolated thiacremonone, a novel sulfur compound from garlic. Here, we investigated the anti-inflammatory and arthritis properties of thiacremonone through inhibition of NF-kappaB since NF-kappaB is known to be a target molecule of sulfur compounds and an implicated transcription factor regulating inflammatory response genes.

METHODS

The anti-inflammatory and arthritis effects of thiacremone in in vivo were investigated in 12-O-tetradecanoylphorbol-13-acetate-induced ear edema, carrageenan and mycobacterium butyricum-induced inflammatory and arthritis models. Lipopolysaccharide-induced nitric oxide (NO) production was determined by Griess method. The DNA binding activity of NF-kappaB was investigated by electrophoretic mobility shift assay. NF-kappaB and inducible nitric oxide synthetase (iNOS) transcriptional activity was determined by luciferase assay. Expression of iNOS and cyclooxygenase-2 (COX-2) was determined by western blot.

RESULTS

The results showed that topical application of thiacremonone (1 or 2 microg/ear) suppressed the 12-O-tetradecanoylphorbol-13-acetate-induced (1 microg/ear) ear edema. Thiacremonone (1-10 mg/kg) administered directly into the plantar surface of hind paw also suppressed the carrageenan (1.5 mg/paw) and mycobacterium butyricum (2 mg/paw)-induced inflammatory and arthritic responses as well as expression of iNOS and COX-2, in addition to NF-kappaB DNA-binding activity. In further in vitro study, thiacremonone (2.5-10 microg/ml) inhibited lipopolysaccharide (LPS, 1 microg/ml)-induced nitric oxide (NO) production, and NF-kappaB transcriptional and DNA binding activity in a dose dependent manner. The inhibition of NO by thiacremonone was consistent with the inhibitory effect on LPS-induced inducible nitric oxide synthase (iNOS) and COX-2 expression, as well as iNOS transcriptional activity. Moreover, thiacremonone inhibited LPS-induced p50 and p65 nuclear translocation, resulting in an inhibition of the DNA binding activity of the NF-kappaB. These inhibitory effects on NF-kappaB activity and NO generation were suppressed by reducing agents dithiothreitol (DTT) and glutathione, and were abrogated in p50 (C62S)-mutant cells, suggesting that the sulfhydryl group of NF-kappaB molecules may be a target of thiacremonone.

CONCLUSIONS

The present results suggested that thiacremonone exerted its anti-inflammatory and anti-arthritic properties through the inhibition of NF-kappaB activation via interaction with the sulfhydryl group of NF-kappaB molecules, and thus could be a useful agent for the treatment of inflammatory and arthritic diseases.

A new onset of systemic lupus erythematosus developed after bee venom therapy

Lupus is a systemic autoimmune disease of an unknown origin, and systemic lupus erythematosus (SLE) can be triggered by numerous stimuli. Bee venom therapy is an alternative therapy that is believed to be effective for various kinds of arthritis. We present here a case of a 49-year-old female who experienced a new onset lupus after undergoing bee venom therapy, and this looked like a case of angioedema. The patient was successfully treated with high dose steroids and antimalarial drugs. We discuss the possibility of bee venom contributing to the development of SLE, and we suggest that such treatment should be avoided in patients with lupus.

Inflexinol inhibits colon cancer cell growth through inhibition of nuclear factor-kappaB activity via direct interaction with p50

Kaurane diterpene compounds have been known to be cytotoxic against several cancer cells through inhibition of nuclear factor-kappaB (NF-kappaB) activity. Here, we showed that inflexinol, a novel kaurane diterpene compound, inhibited the activity of NF-kappaB and its target gene expression as well as cancer cell growth through induction of apoptotic cell death in vitro and in vivo. These inhibitory effects on NF-kappaB activity and on cancer cell growth were suppressed by the reducing agents DTT and glutathione and were abrogated in the cells transfected with mutant p50 (C62S). Sol-gel biochip and surface plasmon resonance analysis showed that inflexinol binds to the p50 subunit of NF-kappaB. These results suggest that inflexinol inhibits colon cancer cell growth via induction of apoptotic cell death through inactivation of NF-kappaB by a direct modification of cysteine residue in the p50 subunit of NF-kappaB.

Bee venom suppresses LPS-mediated NO/iNOS induction through inhibition of PKC-alpha expression

ETHNOPHARMACOLOGICAL RELEVANCE

Bee venom (BV) is a traditional Korean medicine that has been widely used with satisfactory results in the treatment of some immune-related diseases, especially rheumatoid arthritis.

AIM OF THE STUDY

The purpose of this study is to elucidate the molecular mechanism underlying the anti-inflammatory effects of BV, which is used in the treatment of various inflammatory diseases in traditional Korean medicine. We evaluated the anti-inflammatory effect of BV on NO generation and iNOS expression by LPS in rat C6 glioma cells.

MATERIAL AND METHODS

BV was obtained from the National Institute of Agricultural Science and Technology (NIAST) of Korea. Nitrite measurement, Immuno blot analysis, Reverse transcriptase-PCR and Electrophoretic mobility shift assay (EMSA) were used for assessment.

RESULTS

BV suppressed the LPS-induced NO generation and iNOS expression, and it also inhibited the expressions of LPS-induced pro-inflammatory molecules including Cox-2 and IL-1 beta in rat C6 glioma cells. Then, BV inhibited LPS-induced expression of PKC-alpha and MEK/ERK, not p38 and JNK. Moreover, inhibition of LPS-induced iNOS expression by BV was dependent on transcriptional activities of AP-1/NF-kappaB through MEK/ERK pathway.

CONCLUSION

These results indicate that BV suppresses LPS-induced iNOS activation through regulation of PKC-alpha. Accordingly, BV exerts a potent suppressive effect on pro-inflammatory responses in rat C6 glioma cells.

Adenosine analogs and electromagnetic fields inhibit prostaglandin E2 release in bovine synovial fibroblasts

OBJECTIVE

To investigate the role of adenosine analogs and electromagnetic field (EMF) stimulation on prostaglandin E(2) (PGE(2)) release and cyclooxygenase-2 (COX-2) expression in bovine synovial fibroblasts (SFs).

METHODS

SFs isolated from synovia were cultured in monolayer. Saturation and binding experiments were performed by using typical adenosine agonists: N6-cyclohexyladenosine (CHA, A(1)), 2-[p-(2-carboxyethyl)-phenetyl-amino]-5'-N-ethylcarboxamidoadenosine (CGS 21680, A(2A)), 5'-N-ethylcarboxamidoadenosine (NECA, non-selective), N6-(3-iodobenzyl)2-chloroadenosine-5'-N-methyluronamide (Cl-IB-MECA, A(3)). SFs were treated with TNF-alpha (10 ng/ml) and lipopolysaccharide (LPS) (1 microg/ml) to activate inflammatory response. Adenosine analogs were added to control and TNF-alpha- or LPS-treated cultures both in the absence and in the presence of adenosine deaminase (ADA) which is used to deplete endogenous adenosine. Parallel cultures were exposed to EMFs (75 Hz, 1.5 mT) during the period in culture (24h). PGE(2) release was measured by immunoassay. COX-2 expression was evaluated by RT-PCR.

RESULTS

TNF-alpha and LPS stimulated PGE(2) release. All adenosine agonists, except for Cl-IB-MECA, significantly inhibited PGE(2) production. EMFs inhibited PGE(2) production in the absence of adenosine agonists and increased the effects of CHA, CGS 21680 and NECA. In ADA, the inhibition on PGE(2) release induced by CHA, CGS and NECA was stronger than in the absence of ADA and the EMF-inhibitory effect was lost. Changes in PGE(2) levels were associated to modification of COX-2 expression.

CONCLUSIONS

This study supports anti-inflammatory activities of A(1) and A(2A) adenosine receptors and EMFs in bovine SFs. EMF activity appears mediated by an EMF-induced up-regulation of A(2A) receptors. Biophysical and/or pharmacological modulation of adenosine pathways may play an important role to control joint inflammation.

Inductively coupled plasma mass spectrometry determination of metals in honeybee venom

Inductively coupled plasma mass spectrometry (ICP-MS) technique was used to analyze the contamination of selected 20 metals in 32 samples of honeybee venom and to demonstrate differences in the content of these elements. Among the analyzed metal microelements (Al, Co, Cu, Zn, Mn, Mo, B, V, Sr and Ni), macro-elements (Ca, Mg, K and Na) and toxic metals (As, Ba, Pb, Cd, Sb and Cr) were identified. The presented results showed that the metal levels in honeybee venom are much lower than the tolerable upper intake levels for the elements. Also the toxic metal contamination is much lower than the permissible levels for drugs established by the United States Pharmacopeia and the European Pharmacopeia. As opposed to the pharmacopeial tests for metals, a multi-element ICP-MS method has been developed. In order to confirm data obtained, the following steps and parameters were taken into account for the validation of the method: calibration verification, recovery, accuracy, precision, detection limit (LOD), quantitation limit (LOQ), spectral and matrix interference and comparison between ICP-MS and GFAAS (graphite furnace atomic absorption spectrometry) for Mn. All steps of validation proved the accuracy of the results. This is most likely the first study in which the metal content in honeybee venom was evaluated by ICP-MS.

JNK pathway is involved in the inhibition of inflammatory target gene expression and NF-kappaB activation by melittin

Background

Bee venom therapy has been used to treat inflammatory diseases including rheumatoid arthritis in humans and in experimental animals. We previously found that bee venom and melittin (a major component of bee venom) have anti-inflammatory effect by reacting with the sulfhydryl group of p50 of nuclear factor-kappa B (NF-κB) and IκB kinases (IKKs). Since mitogen activated protein (MAP) kinase family is implicated in the NF-κB activation and inflammatory reaction, we further investigated whether activation of MAP kinase may be also involved in the anti-inflammatory effect of melittin and bee venom.

Methods

The anti-inflammatory effects of melittin and bee venom were investigated in cultured Raw 264.7 cells, THP-1 human monocytic cells and Synoviocytes. The activation of NF-κB was investigated by electrophoretic mobility shift assay. Nitric oxide (NO) and prostaglandin E₂ (PGE₂) were determined either by Enzyme Linked Immuno Sorbent Assay or by biochemical assay. Expression of IκB, p50, p65, inducible nitric oxide synthetase (iNOS), cyclooxygenase-2 (COX-2) as well as phosphorylation of MAP kinase family was determined by Western blot.

Results

Melittin (0.5–5 μg/ml) and bee venom (5 and 10 μg/ml) inhibited lipopolysaccharide (LPS, 1 μg/ml) and sodium nitroprusside (SNP, 200 μM)-induced activation of c-Jun NH2-terminal kinase (JNK) in RAW 264.7 cells in a dose dependent manner. However, JNK inhibitor, anthra [1,9-cd]pyrazole-6 (2H)-one (SP600215, 10–50 μM) dose dependently suppressed the inhibitory effects of melittin and bee venom on NF-κB dependent luciferase and DNA binding activity via suppression of the inhibitory effect of melittin and bee venom on the LPS and SNP-induced translocation of p65 and p50 into nucleus as well as cytosolic release of IκB. Moreover, JNK inhibitor suppressed the inhibitory effects of melittin and bee venom on iNOS and COX-2 expression, and on NO and PGE₂ generation.

Conclusion

These data show that melittin and bee venom prevent LPS and SNP-induced NO and PGE₂ production via JNK pathway dependent inactivation of NF-κB, and suggest that inactivation of JNK pathways may also contribute to the anti-inflammatory and anti-arthritis effects of melittin and bee venom.

Effects of melittin on the production of matrix metalloproteinase-1 and -3 in rheumatoid arthritic fibroblast-like synoviocytes

Bee venom (BV) has been used in patients with rheumatoid arthritis, a condition characterized by rheumatoid joint destruction mediated, in large part, by matrix metalloproteinases (MMPs). We investigated the effects of melittin, a major component of bee venom, on the production of MMPs in human rheumatoid arthritic fibroblast-like synoviocytes (FLS). Lipopolysaccharide (LPS)-stimulated MMP3 production was significantly inhibited by melittin, which also inhibited LPS-induced DNA binding by nuclear factor kappaB (NF-kappaB). Mellitin had no effect on IL-1beta- or TNF-alpha-induced MMP1 or MMP3 production and did not decrease LPS-induced secretion of MMP1. Taken together, these findings suggest that melittin may exert its anti-rheumatoid effects, at least in part, by inhibiting MMP3 production, most likely through inhibition of NF-kappaB activity.

Effects of bee venom on cholecystokinin octapeptide-induced acute pancreatitis in rats

OBJECTIVES

Bee venom (BV) has frequently been used as a remedy for inflammatory diseases. The aim of this study was to investigate the effect of BV on cholecystokinin octapeptide (CCK-8)-induced acute pancreatitis (AP) in rats.

METHODS

The BV pretreatment group: 0.25 mg/kg BV was administered subcutaneously, followed by 75 mug/kg CCK-8 subcutaneously 3 times after 1, 3, and 5 hours. This whole procedure was repeated for 5 days.

CONTROL GROUP

CCK-8 subcutaneously 3 times after 1, 3, and 5 hours for 5 days. The BV posttreatment group: CCK-8 subcutaneously 3 times at an interval of 2 hours for 3 days, and then 0.25 mg/kg of BV was administered subcutaneously.

CONTROL GROUP

CCK-8 subcutaneously 3 times at an interval of 2 hours for 3 days.

RESULTS

The BV pretreatment and posttreatment ameliorated many of the examined laboratory parameters (the pancreatic weight [PW]/body weight [BW] ratio, the serum amylase and lipase activity) and reduced histological damages in pancreas. Furthermore, BV pretreatment reduced the production of tumor necrosis factor-alpha, interleukin 1, and interleukin 6 and also decreased pancreatic nuclearfactor-kappaB binding activity compared with saline-treated group in the AP model. The BV also increased heat shock protein 60 (HSP60) and heat shock protein 72 (HSP72) compared with the saline-treated group in the AP model.

CONCLUSIONS

These findings suggest that the anti-inflammatory effect of BV in CCK-8-induced AP seems to be mediated by inhibiting nuclear factor-kappaB binding activity, and that BV may have a protective effect against AP.

Preventive effect of water containing magnesium ion on paw edema in adjuvant-induced arthritis rat

We demonstrate the preventive effect of bittern water (BW), which enables the effective intake of magnesium ion (Mg(2+)), on paw edema in adjuvant-induced arthritis (AA) rat. BW (five kinds; BW-1, 2, 3, 4, 5) containing 10-200 mg/l Mg(2+) was used in this study. Arthritis was induced by the injection of 50 microl of a suspension of 10 mg/ml heat-killed butyricum (Mycobacterium butyricum) in Bayol F oil into the plantar region of the right hind foot and tail of rats. Paw edema of the right and left hind feet of AA rats were reduced by the administration of BW for 14 d after adjuvant injection in comparison with those of AA rats administered purified water. The preventive effect increased with the increasing Mg(2+) content of the BW. In addition, a combination of indomethacin (IM, 2 mg/kg) and BW-5 (200 mg/l Mg(2+)) prevented paw edema of the right and left hind feet of AA rats in comparison with IM alone. The fate of plasma IM after the oral administration of the combined IM (2 mg/kg/d) and BW-5 was similar to that after the administration of IM alone. In conclusion, the oral administration of Mg(2+) to AA rats potently prevents the development of inflammation, and the combination of IM and Mg(2+) may provide an effective therapy of arthritic edema.

Melittin induces Bcl-2 and caspase-3-dependent apoptosis through downregulation of Akt phosphorylation in human leukemic U937 cells

Melittin (MEL), a major polypeptide in bee venom (BV), is known to inhibit proliferation and induce apoptosis in cancer cells. However, the molecular mechanisms involved in MEL-induced apoptosis have not been fully elucidated, especially in human leukemic cells. In the present study, we report that MEL induces apoptosis in leukemic U937 cells through downregulating Akt signal pathways. Furthermore, MEL-induced apoptosis was accompanied by downregulation of Bcl-2 and activation of caspase-3. The induction of apoptosis also was accompanied by the downregulation of the inhibitor of apoptosis protein (IAP) family proteins. Treatment of U937 cells with the caspase-3 inhibitor, z-DEVD-fmk, was capable of significantly restoring cell viability in MEL-treated cells. Additionally, the caspase-3 mediated apoptotic response was significantly attenuated in Bcl-2-overexpressing U937 cells treated with MEL. These results indicate that downregulation of Bcl-2 plays a major role in activation of caspase-3 following MEL exposure. MEL also triggered downregulation of Akt. LY294002 (an inhibitor of Akt) significantly decreased cell viability and increased the proportion of cells with sub-G1 phase DNA content. The results indicated that key regulators in MEL-induced apoptosis in human leukemic U937 cells include Bcl-2 and caspase-3, which are controlled through the Akt signaling pathway.

Cytotoxicity of honeybee (Apis mellifera) venom in normal human lymphocytes and HL-60 cells

Whole bee venom (BV) is used to treat inflammatory diseases in Korean traditional medicine. Various studies have demonstrated anti-inflammatory and anticancer effects of BV. The toxicity of individual components of BV has been widely studied, although few studies have reported on the toxicity of BV. We sought to evaluate the cytotoxicity of BV in normal human lymphocytes and HL-60 cells. When cells were treated with BV at concentrations of 1 or 5 microg/ml, BV induced cell death in a time-dependent manner until 24 h, but these cytotoxic effects ended thereafter. When cells were treated with BV at a concentration of 10 microg/ml, however, viability decreased until 72 h, which may have been due to the half-life of BV. Whole BV also inhibited proliferation in these cells. BV induced DNA fragmentation and micronuclei in HL-60 cells and DNA fragmentation in human lymphocytes. Phosphate and tensin homolog (PTEN) up-regulation in HL-60 cells may induce S-phase cell cycle arrest. Forkhead transcription factor (FKHR and FKHRL1) up-regulation in human lymphocytes by whole BV treatment may be involved in the repair of damaged DNA and reduce genotoxicity. Based on these results, whole BV may exert cytotoxicity in these two cells in a different fashion.

Apis mellifera venom and melittin block neither NF-kappa B-p50-DNA interactions nor the activation of NF-kappa B, instead they activate the transcription of proinflammatory genes and the release of reactive oxygen intermediates

Many alternative treatment approaches, originating from Asia, are becoming increasingly popular in the Western hemisphere. Recently, an article published in a renowned journal reported that venom of apis mellifera (bee venom (BV)) and melittin mediate immune-modulating effects by blocking the activation of the transcription factor NF-kappaB. Such a modus operandi would corroborate the many claims of beneficial effects of BV treatment and give immediate credit to this form of therapy. Fibroblast-like synoviocytes from rheumatoid arthritis patients and dermal fibroblast cells and white blood cells from healthy volunteers were used to study the effects of BV and melittin on the activation of NF-kappaB and a series of genes that are markers of inflammation. EMSAs demonstrate that neither BV nor melittin blocked IL-1beta-induced NF-kappaB activation; neither did they affect phosphorylation or degradation of IkappaB. Contrary to published data, even high concentrations of BV and melittin were without any effect on NF-kappaB-p50-DNA interactions. More importantly, in fibroblast-like synoviocytes, but also in dermal fibroblasts as well as in mononuclear cells exposed to BV or melittin, mRNA levels of several proinflammatory genes are significantly increased, and Western blot data show elevated cyclooxygenase-2 protein levels. Furthermore, exposure to BV higher than 10 mug/ml resulted in disintegration of all cell types tested. In addition, large quantities of oxygen radicals are produced in a dose-dependent manner in leukocytes exposed to BV. Taken together, data presented in this work do not corroborate an earlier report regarding the effectiveness of BV as an inhibitor of the transcription factor NF-kappaB.

Melittin, a major bioactive component of bee venom toxin, inhibits PDGF receptor beta-tyrosine phosphorylation and downstream intracellular signal transduction in rat aortic vascular smooth muscle cells

Studies previously reported that melittin, a major bioactive component of bee venom, inhibits vascular smooth muscle cell (VSMC) proliferation through suppression of nuclear factor (NF)-kappaB and Akt activation and through enhancement of proapoptotic protein expression. In this study, the effects of melittin were investigated on the tyrosine phosphorylation of platelet-derived growth factor (PDGF) beta receptor (Rbeta) and its downstream intracellular signal transduction. When combined with PDGF-Rbeta inhibitor, melittin exhibited a synergic inhibitory effect on PDGF-BB-induced rat aortic VSMC proliferation. In addition, melittin inhibited PDGF-Rbeta phosphorylation in a concentration-dependent manner. Accordingly, the downstream signal transduction of PDGF-Rbeta, such as ERK1/2, Akt, and PLCgamma1 phosphorylation, was also inhibited by melittin in the same manner. These findings suggest that, in addition to suppressing NF-kappaB activation, the antiproliferative effect of melittin in VSMC may be mediated, at least in part, by the inhibition of PDGF-Rbeta tyrosine phosphorylation and its downstream intracellular signal transduction.

Bee venom and melittin reduce proinflammatory mediators in lipopolysaccharide-stimulated BV2 microglia

Bee venom (BV), well known as a traditional Oriental medicine, has been shown to exhibit anti-arthritic and anti-carcinogenic effects. However, the molecular mechanisms responsible for the anti-inflammatory activity of BV have not been elucidated in microglia. In the present study, we investigated the anti-inflammatory effect of BV and its major component, melittin (MEL), on lipopolysaccharide (LPS)-stimulated BV2 microglia. Our results indicate that BV and MEL suppress LPS-induced nitric oxide (NO) and inducible NO synthase (iNOS) expression in a dose-dependent manner, without causing cytotoxicity in BV2 microglia. Moreover, BV and MEL suppressed LPS-induced activation of nuclear factor kappa B (NF-kappaB) by blocking degradation of IkappaBalpha and phosphorylation of c-Jun N-terminal kinase (JNK) and Akt, which resulted in inhibition of iNOS expression. Our data also indicate that BV and MEL exert anti-inflammatory effects by suppressing the transcription of cyclooxygenase (COX)-2 genes and proinflammatory cytokines, such as interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)-alpha. BV and MEL also attenuated the production of prostaglandin E(2) (PGE(2)). These results demonstrate that BV and MEL possess a potent suppressive effect on proinflammatory responses of BV2 microglia and suggest that these compounds may offer substantial therapeutic potential for treatment of neurodegenerative diseases that are accompanied by microglial activation.

Inhibitory effects of melittin on the production of lipopolysaccharide-induced matrix metalloproteinase 3 in human osteoarthritic chondrocytes

In continuation of our previous study which explored the effect of bee venom (BV) on the global gene expression profiles in lipopolysaccharide (LPS)-treated human chondrosarcoma cells, we investigated herein the effect of melittin, a major component of BV, on the productions of matrix metalloproteinases (MMPs) 1, 3, and 13 in primary cultured human arthritic chondrocytes. Increased generations of MMPs 1, 3, and 13 were observed by MMPs stimulating agents LPS, tumor necrosis factor alpha (TNF-alpha), and interleukin 1beta (IL-1beta). The generations of LPS (1 microg/ml)-induced MMPs 1 and 13 were not decreased by melittin, whereas that of LPS-stimulated MMP 3 was significantly inhibited by melittin. IL-1beta (10ng/ml) and TNF-alpha (10ng/ml)-induced MMPs 1, 3 and 13, however, were not decreased by melittin. Immunoblot analysis revealed that melittin exerted no effect on the LPS-stimulated expression levels of MMPs 1 and 13 but attenuated the LPS-induced MMP 3, which is consistent with the enzyme-linked immunosorbent assay (ELISA) data. Taken together, these findings suggest melittin may exert its anti-arthritic effect, at least in part, by inhibiting LPS-stimulated MMP 3 production in human osteoarthritic chondrocytes.

Osteochondral destruction in the hand following bee stings: a case report of an infant

We report an infant who developed arthritis with osteochondral destruction in a hand after being stung by bees. The clinical findings resembled those reported as "beekeeper's arthropathy", but the radiological findings were more severe. Histology of the resected specimen revealed fibrous granulation tissue with infiltration of inflammation cells.

Inhibitory effect of snake venom toxin fromVipera lebetina turanicaon hormone-refractory human prostate cancer cell growth: induction of apoptosis through inactivation of nuclear factor κB

We investigated whether the snake venom toxin (SVT) from Vipera lebetina turanica inhibits cell growth of human prostate cancer cells by inducing apoptosis and also studied possible signaling pathways involved in this cell death. SVT inhibited growth of PC-3 and DU145 cells, androgen-independent prostate cancer cells, but not LNCaP cells, a human androgen-dependent prostate cancer cell. Cells were arrested in the G(2)-M phase by SVT with a concomitant decrease in the expression of the G(2)-M phase regulatory protein cyclin B1 and were also arrested in the G(1)-S phase with decreasing expression of cyclin-dependent kinase 4, cyclin D1 and cyclin E. In addition to the growth-inhibitory effect, SVT increased the induction of apoptotic cell death. Untreated PC-3 cells show high DNA binding activity of nuclear factor kappaB (NF-kappaB), an antiapoptotic transcriptional factor, but this was inhibited by SVT and accompanied by a significant inhibition of p50 translocation into the nucleus, as well as phosphorylation of inhibitory kappaB. Consistent with the induction of apoptosis and inhibition of NF-kappaB, this toxin increased the expression of proapoptotic proteins such as p53, Bax, caspase-3, and caspase-9, but down-regulated antiapoptotic protein Bcl-2. However, SVT did not show an inhibitory effect on cell growth and caspase-3 activity in cells carrying mutant p50 and inhibitory kappaB kinase plasmids. Confocal microscopy analysis showed that SVT is taken up into the nucleus of the cells. These findings suggest that a nanogram concentration range of SVT from V. lebetina turanica could inhibit hormone-refractory human prostate cancer cell growth, and the effect may be related to NF-kappaB signal-mediated induction of apoptosis.

Key regulators in bee venom-induced apoptosis are Bcl-2 and caspase-3 in human leukemic U937 cells through downregulation of ERK and Akt

Bee venom (BV) has been known to inhibit proliferation and induce apoptosis in cancer cells. However, the molecular mechanisms involved in BV-induced apoptosis are still uncharacterized in human leukemic cells. In the present study, we report that BV induces apoptosis in leukemic U937 cells through downregulation of ERK and Akt signal pathway. Furthermore, BV-induced apoptosis was accompanied by downregulation of Bcl-2, activation of caspase-3 and a subsequent poly(ADP-ribose)polymerase (PARP) cleavages. The induction of apoptosis also was accompanied by the downregulation of the inhibitor of apoptosis protein (IAP) family proteins. Caspase-3 inhibitor, z-DEVD-fmk, was significantly capable of restoring cell viability and BV-induced apoptosis through caspase-3 activation was significantly attenuated in Bcl-2-overexpressing cells. These results indicate that downregulation of Bcl-2 plays a major role in the initiation as an activator of a caspase-3 involved with BV-induced apoptosis. BV also triggered the activation of p38 MAPK and JNK, and downregulation of ERK and Akt. PD98059 (an inhibitor of ERK) or LY294002 (an inhibitor of Akt), but not an inhibitor of p38 MAPK and JNK, significantly decreased cell viability and increased lactate dehydrogenase (LDH) release. The results indicated that key regulators in BV-induced apoptosis are Bcl-2 and caspase-3 in human leukemic U937 cells through downregulation of the ERK and Akt signal pathway.

Melittin inhibits inflammatory target gene expression and mediator generation via interaction with IkappaB kinase

We previously found that bee venom (BV) and melittin (a major component of BV) has anti-inflammatory effect by reacting with the sulfhydryl group of p50 of NF-kappaB. Since the sulfhydryl group is present in IkappaB kinase (IKKalpha and IKKbeta), anti-inflammatory effect of melittin via interaction with IKKs was investigated. We first examined binding of melittin to IKKs using surface plasmon resonance analyzer. Melittin binds to IKKalpha (K(d) = 1.34 x 10(-9) M) and IKKbeta (K(d) = 1.01 x 10(-9) M). Consistent with the high binding affinity, melittin (5 and 10 microg/ml) and BV (0.5, 1 and 5 microg/ml) suppressed sodium nitroprusside, TNF-alpha and LPS induced-IKKbeta and IKKbeta activities, IkappaB release, and NF-kappaB activity as well as the expressions of iNOS and COX-2, and the generation of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) in Raw 264.7 mouse macrophages and synoviocytes obtained from rheumatoid arthritis patients. The binding affinities of melittin to mutant IKKs, was reduced, and the inhibitory effect of melittin on IKK and NF-kappaB activities, and NO and PGE(2) generation were abrogated by the reducing agents or in Raw 264.7 transfected with mutant plasmid IKKalpha (C178A) or IKKbeta (C179A). These results suggest that melittin binding to the sulfhydryl group of IKKs resulted in reduced IKK activities, IkappaB release, NF-kappaB activity and generation of inflammatory mediators, indicating that IKKs may be also anti-inflammatory targets of BV.

Study of the interaction between Apis mellifera venom and micro-heterogeneous systems

The bee venom, used in treatment of inflammatory and articular diseases, is a complex mixture of peptides and enzymes and the presence of tryptophan allows the investigation by fluorescence techniques. Steady state and time-resolved fluorescence spectroscopy were used to study the interaction between bee venom extracted from Apis mellifera and three micro heterogeneous systems: sodium dodecylsulphate (SDS) micelles, sodium dodecylsulphate-poly(ethylene oxide) (SDS-PEO) aggregates, and the polymeric micelles LUTROL F127, formed by poly(ethylene oxide)-poly(propylene oxide)- poly(ethylene oxide). Fluorescence parameters in buffer solution were typical of peptides containing tryptophan exposed to the aqueous medium, and they gradually changed upon the addition of surfactant and polymeric micelles, demonstrating the interaction of the peptides with the micro heterogeneous systems. Quenching experiments were carried out using the N-alkylpyridinium ions (ethyl, hexyl, and dodecyl) as quenchers. In buffer solution the quenching has low efficiency and is independent of the alkyl chain length of the quencher. In the presence of the micro heterogeneous systems the extent of static and dynamic quenching enhanced, showing that both fluorophore and quenchers reside in the microvolume of the aggregates. The more hydrophobic quencher (dodecyl pyridinium ion) provides higher values for K (SV) and dynamic quenching constants, and SDS-PEO aggregates are most efficient to promote interaction between peptides and alkyl pyridinium ions. The results proved that bee venom interacts with drug delivery micelles of the copolymer LUTROL F127.

Enhanced expression of mRNA for nuclear factor kappaB1 (p50) in CD34+ cells of the bone marrow in rheumatoid arthritis

Bone marrow CD34+ cells from rheumatoid arthritis (RA) patients have abnormal capacities to respond to tumor necrosis factor (TNF)-α and to differentiate into fibroblast-like cells producing matrix metalloproteinase (MMP)-1. We explored the expression of mRNA for nuclear factor (NF)κB in RA bone marrow CD34+ cells to delineate the mechanism for their abnormal responses to TNF-α. CD34+ cells were purified from bone marrow samples obtained from 49 RA patients and 31 osteoarthritis (OA) patients during joint operations via aspiration from the iliac crest. The mRNAs for NFκB1 (p50), NFκB2 (p52) and RelA (p65) were examined by quantitative RT-PCR. The expression of NFκB1 mRNA in bone marrow CD34+ cells was significantly higher in RA than in OA, whereas there was no significant difference in the expression of mRNA for NFκB2 and RelA. The expression of NFκB1 mRNA was not correlated with serum C-reactive protein or with the treatment with methotrexate or oral steroid. Silencing of NFκB1 by small interfering RNA abrogated the capacity of RA bone marrow CD34+ cells to differentiate into fibroblast-like cells and to produce MMP-1 and vascular endothelial growth factor upon stimulation with stem cell factor, granulocyte-macrophage colony stimulating factor and TNF-α without influencing their viability and capacity to produce β2-microglobulin. These results indicate that the enhanced expression of NFκB1 mRNA in bone marrow CD34+ cells plays a pivotal role in their abnormal responses to TNF-α and, thus, in the pathogenesis of RA.

Dihydrocucurbitacin B, isolated from Cayaponia tayuya, reduces damage in adjuvant-induced arthritis

23,24-Dihydrocucurbitacin B, from the anti-rheumatic plant Cayaponia tayuya, was tested on arthritis induced by adjuvant to corroborate the anti-inflammatory properties of this plant. Arthritis was induced in Lewis rats; the resulting arthritic rats were then treated with dihydrocucurbitacin B (1 mg/kg orally, daily, 1 week). The effect of dihydrocucurbitacin B on the synthesis, release, and activity of pro-inflammatory enzymes (elastase, cyclooxygenase-2, and nitric oxide synthase-2) as well as its effect on different mediators (tumor necrosis factor-alpha and interleukin-1beta) were determined. Dihydrocucurbitacin B modified the evolution of the clinical symptoms, reducing the swelling and bone and tissue damage along with the development of the disease, modifying the cell infiltration and the expression of both nitric oxide synthase-2 and cyclooxygenase-2. In addition, it decreased the tumor necrosis factor-alpha and interleukin-1beta production in lymphocytes, but did not modify it in macrophages.

Melittin inhibits vascular smooth muscle cell proliferation through induction of apoptosis via suppression of nuclear factor-kappaB and Akt activation and enhancement of apoptotic protein expression

In the present study, we have investigated the bee venom (BV) and melittin (a major component of BV)-mediated antiproliferative effect and defined its mechanisms of action in cultured rat aortic vascular smooth muscle cell(s) (VSMC). BV and melittin ( approximately 0.4-0.8 microg/ml) effectively inhibited 5% fetal bovine serum-induced and 50 ng/ml platelet-derived growth factor BB (PDGF-BB)-induced VSMC proliferation. The regulation of apoptosis has attracted much attention as a possible means of eliminating excessively proliferating VSMC. In the present study, the treatment of BV and melittin strongly induced apoptosis of VSMC. To investigate the antiproliferative mechanism of BV and melittin, we examined the effect of melittin on nuclear factor kappaB (NF-kappaB) activation, the PDGF-BB-induced IkappaBalpha phosphorylation, and its degradation were potently inhibited by melittin and whether DNA binding activity and nuclear translocation of NF-kappaB p50 subunit in response to the action of PDGF-BB were potently attenuated by melittin. In further investigations, melittin markedly inhibited the PDGF-BB-induced phosphorylation of Akt and weakly inhibited phosphorylation of extracellular signal-regulated kinase 1/2, upstream signals of NF-kappaB. Treatment of melittin also potently induced proapoptotic protein p53, Bax, and caspase-3 expression but decreased antiapoptotic protein Bcl-2 expression. These results suggest the antiproliferative effects of BV and melittin in VSMC through induction of apoptosis via suppressions of NF-kappaB and Akt activation and enhancement of apoptotic signaling pathway.

Cobrotoxin Inhibits NF-κB Activation and Target Gene Expression through Reaction with NF-κB Signal Molecules

Cobrotoxin is known to bind with cysteine residues of biological molecules such as nicotine acetylcholine receptor. Cobrotoxin may modify IKKs and p50 through protein-protein interaction since cysteine residues are present in the kinase domains of IKKalpha and IKKbeta and in the p50 of NF-kappaB. Our surface plasmon resonance analysis showed that cobrotoxin directly binds to p50 (K(d) = 1.54 x 10(-)(5) M), IKKalpha (K(d) = 3.94 x 10(-)(9) M) and IKKbeta (K(d) = 3.4 x 10(-)(8) M) with high binding affinity. Moreover, these protein-protein interactions suppressed the lipopolysaccharide (LPS, 1 microg/mL)- and the sodium nitroprusside (SNP, 200 microM)-induced DNA binding activity of NF-kappaB and NF-kappaB-dependent luciferase activity in astrocytes and Raw 264.7 macrophages. These inhibitory effects were correlated with the inhibition of IkappaB release and p50 translocation. Inhibition of NF-kappaB by cobrotoxin resulted in reductions in the LPS-induced expressions of COX-2, iNOS, cPLA(2), IL-4, and TNF-alpha in astrocytes and in COX-2 expression induced by SNP, LPS, and TNF-alpha in astrocytes. Moreover, these inhibitory effects of cobrotoxin were reversed by adding reducing agents, dithiothreitol and glutathione. In addition, cobrotoxin did not have any inhibitory effect on NF-kappaB activity in cells carrying mutant p50 (C62S), IKKalpha (C178A), and IKKbeta (C179A), with the exception of IKKbeta (K44A) mutant plasmid. Confocal microscopic analysis showed that cobrotoxin is uptaken into the nucleus of cells. These results demonstrate that cobrotoxin directly binds to the sulfhydryl groups of p50 and IKKs, and that this results in reduced IkappaB release and the translocation of p50, thereby inhibiting the activation of NF-kappaB.

Survey of the year 2004 commercial optical biosensor literature

The year 2004 represents a milestone for the biosensor research community: in this year, over 1000 articles were published describing experiments performed using commercially available systems. The 1038 papers we found represent an approximately 10% increase over the past year and demonstrate that the implementation of biosensors continues to expand at a healthy pace. We evaluated the data presented in each paper and compiled a 'top 10' list. These 10 articles, which we recommend every biosensor user reads, describe well-performed kinetic, equilibrium and qualitative/screening studies, provide comparisons between binding parameters obtained from different biosensor users, as well as from biosensor- and solution-based interaction analyses, and summarize the cutting-edge applications of the technology. We also re-iterate some of the experimental pitfalls that lead to sub-optimal data and over-interpreted results. We are hopeful that the biosensor community, by applying the hints we outline, will obtain data on a par with that presented in the 10 spotlighted articles. This will ensure that the scientific community at large can be confident in the data we report from optical biosensors.