Bee venom at different concentrations modulates the aeroallergen-induced activation of nasal polyp epithelial cells

Bee venom (BV) has long been used as an oriental traditional medicine for the control of pain and inflammation. However, BV's anti-inflammatory mechanisms remain unclear. This study aimed to clarify the potential clinical efficacy of BV concerning the anti-inflammatory effect on nasal epithelial cell inflammation. Nasal polyp epithelial cells were obtained from patients. Cells were exposed to Alternaria alternata, Aspergillus nigra, Dermatophagoides pteronyssinus, Dermatophagoides farina and lipopolysaccharide with or without various concentrations of BV. Interleukin (IL)-6, IL-8, and granulocyte macrophage colony-stimulating factor were measured to determine the activation of epithelial cells. Nuclear factor-ĸB (NF-ĸB) and activator protein 1 expression and activity were determined with Western blot analysis and ELISA. Cytotoxicity of BV was measured using a CellTiter-96® aqueous cell proliferation assay kit. Cell survival was significantly decreased at BV concentrations exceeding 5 µg/ml. Fungi-induced cytokine production was more effectively inhibited by BV than house dust mite. Alternaria enhanced NF-ĸB expression, which was strongly inhibited by BV. BV appears to be relatively safe, and is of potential value for the treatment of airway inflammation and/or immunologic diseases.

The inhibitory effect of chimeric decoy oligodeoxynucleotide against NF-κB and Sp1 in renal interstitial fibrosis

The pathophysiology of chronic renal disease is characterized by a progressive loss of renal function and deposition of the extracellular matrix, leading to widespread tissue fibrosis. Much of the matrix in chronic renal disease is synthesized by interstitial myofibroblasts, recruited from resident fibroblasts and circulating precursors. These changes are believed to be derived from epithelial-mesenchymal transition (EMT) of tubuloepithelial cells. To develop a novel therapeutic approach for treating renal fibrosis, we examined the simultaneous inhibition of the transcription factors NF-κB and Sp1 in a mouse model of unilateral ureteral obstruction (UUO). To simultaneously inhibit both NF-κB and Sp1, we developed chimeric (Chi) decoy oligodeoxynucleotide (ODN) which contained binding sequences for both NF-κB and Sp1 in a single decoy molecule to enhance the effective use of decoy ODN strategy. Chi decoy ODN significantly attenuated tubulointerstitial fibrosis in a mouse model of UUO compared to scrambled decoy ODN, as demonstrated by the reduced interstitial volume, macrophage infiltration, and fibrosis-related gene expression. Interestingly, Chi decoy ODN also regulated EMT-related gene expression, leading to the inhibition of renal fibrotic changes in vivo and in vitro. The present study demonstrates the feasibility of Chi decoy ODN treatment for preventing renal fibrosis and EMT processes. This strategy might be useful to improve the clinical outcome after chronic renal disease.

Ascochlorin inhibits growth factor-induced HIF-1α activation and tumor-angiogenesis through the suppression of EGFR/ERK/p70S6K signaling pathway in human cervical carcinoma cells

Ascochlorin, a non-toxic prenylphenol compound derived from the fungus Ascochyta viciae, has been shown recently to have anti-cancer effects on various human cancer cells. However, the precise molecular mechanism of this anti-cancer activity remains to be elucidated. Here, we investigated the effects of ascochlorin on hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) expression in human epidermoid cervical carcinoma CaSki cells. Ascochlorin inhibited epidermal growth factor (EGF)-induced HIF-1α and VEGF expression through multiple potential mechanisms. First, ascochlorin selectively inhibited HIF-1α expression in response to EGF stimulation, but not in response to hypoxia (1% O(2)) or treatment with a transition metal (CoCl(2)). Second, ascochlorin inhibited EGF-induced ERK-1/2 activation but not AKT activation, both of which play essential roles in EGF-induced HIF-1α protein synthesis. Targeted inhibition of epidermal growth factor receptor (EGFR) expression using an EGFR-specific small interfering RNA (siRNA) diminished HIF-1α expression, which suggested that ascochlorin inhibits HIF-1α expression through suppression of EGFR activation. Finally, we showed that ascochlorin functionally abrogates in vivo tumor angiogenesis induced by EGF in a Matrigel plug assay. Our data suggest that ascochlorin inhibits EGF-mediated induction of HIF-1α expression in CaSki cells, providing a potentially new avenue of development of anti-cancer drugs that target tumor angiogenesis.

Melittin has an inhibitory effect on TNF-α-induced migration of human aortic smooth muscle cells by blocking the MMP-9 expression

Matrix metalloproteinases-9 (MMP-9) plays an important role in the pathogenesis of atherosclerosis and migration of vascular smooth muscle cells (VSMCs) after an arterial injury. In this study, we investigated the potential molecular mechanisms underlying the anti-atheroscleroic effects of melittin, a major component of bee venom, in human aortic smooth muscle cells (HASMCs). Melttin significantly suppressed MMP-9 and MMP-2 secretion, as well as TNF-α-induced MMP-9 expression in the HASMCs. In addition, we found that the inhibitory effects of melittin on TNF-α-induced MMP-9 protein expression are associated with the inhibition of MMP-9 transcription levels. Mechanistically, Melittin suppressed TNF-α-induced MMP-9 activity by inhibiting the phosphorylation of p38 and ERK1/2, but did not affect the phosphorylation of JNK and Akt. Reporter gene and western blotting assays showed that melittin inhibits MMP-9 transcriptional activity by blocking the activation of NF-κB via IκBα signaling pathway. Moreover, the matrigel migration assay showed that melittin reduced TNF-α-induced HASMC migration. These results suggest that melittin suppresses TNF-α-induced HASMC migration through the selective inhibition of MMP-9 expression and provide a novel role of melittin in the anti-atherosclerotic action.

Alpha-lipoic acid attenuates atherosclerotic lesions and inhibits proliferation of vascular smooth muscle cells through targeting of the Ras/MEK/ERK signaling pathway

An infectious burden has been suggested to be associated with atherosclerosis in humans, based on the shared and underlying inflammatory responses during infection and atherosclerosis. However, the efficacy of anti-atherogenic drugs is yet to be tested against atherosclerosis in a scenario involving an infectious burden. We have examined alpha-lipoic acid (ALA) for anti-atherogenic effects in a hypercholesterolemic diet-induced atherosclerotic mouse model with inflammatory stimulation. C57BL/6 mice were fed with a hypercholesterolemic diet for 12 weeks to induce atherosclerosis. Lipopolysaccharide was intraperitoneally injected for the 1st week of study to simulate underlying infectious burden during development of atherosclerosis. ALA treatment alleviated atherosclerotic pathologies and reduced serum cholesterol and inflammatory cytokines. Consistently, atherosclerotic markers were improved by ALA treatment. In addition, ALA attenuated the proliferation and migration of vascular smooth muscle cells upon platelet-derived growth factor stimulation through the targeting of the Ras-MEK1/2-ERK1/2 pathway. This study demonstrates the efficacy of ALA on atherosclerosis with immunological complication, by showing that ALA modulates multiple pathogenic aspects of atherosclerosis induced by a hypercholesterolemic diet with inflammatory stimulation consisting of hypercholesterolemia, inflammation and VSMC activation.

Skin sensitization study of bee venom (Apis mellifera L.) in guinea pigs and rats

BACKGROUND

Bee venom (Apis mellifera L., BV) possessing a rich source of pharmacologically active substances has the potential to be used as a cosmetic ingredient for antiaging, antiinflammatory and antibacterial functions. The aim of this study was to assess the skin sensitization of BV on experimental animals using the Buehler test.

MATERIALS AND METHODS

Guinea pigs were randomly allocated into three groups of BV-sensitization, positive control-sensitization, and ethyl alcohol-sensitization group for induction and challenge. On the other hand, two groups of rats were administered with BV at doses of 0 and 1500 mg/kg. Clinical signs, mortality and body weight changes were continually monitored during the study period.

RESULTS

No treatment-related clinical signs or body weight changes were observed in both animal models. The average skin reaction evaluated by erythema and edema on the challenge sites, and sensitization rate in the BV-sensitization group of guinea pigs were substantially low compared with those in positive control group, representing a negligible sensitizing potential of BV.

CONCLUSION

It was concluded that BV was well tolerated and exhibited no dermal irritation potential in guinea pigs and rats. Our findings may provide a developmental basis of BV for a cosmetic ingredient or external application for topical uses.

The possibility of microbial cellulose for dressing and scaffold materials

In recent years, natural polymers such as cellulose, alginate and chitosan have been used worldwide as biomedical materials and devices, as they offer more advantages over synthetic polymers. The aim of this study was to clarify the usefulness of microbial cellulose (MC) for use as a dressing and scaffold material. For evaluating the biodegradability and toxicity of MC, we divided the rats (n = 12) into two groups (the implanted group and the non-implanted group). In the implanted group, we implanted the film type of MC in the backs of six rats. In the non-implanted group, however, we did not implant the film type of MC in the backs of the six rats. Four weeks later, we compared two groups by the gross, histological and biochemical characteristics by using blood and tissue samples. To evaluate the wound healing effects of MC, three full-thickness skin defects were made on the backs of each rat (n = 20). Three wounds on the backs of the same rats were treated with other dressing materials, namely, Vaseline gauze (group Con), Algisite M(®) (group Alg) and MC (group MC). We analysed the gross, histological and biochemical characteristics by western blotting. MC was found to be biodegradable and non-toxic. On day 3, the MC film was visible under the subcutaneous tissue; however, after 4 weeks, no remnants of the film were visible under the subcutaneous tissue. Furthermore, there was no evidence of MC-induced toxicity. Moreover, group MC showed more rapid wound healing compared with group Con. On day 14 after skin excision, group MC showed greater decrease in wound size compared with group Con (33% versus 7·2%). The wound healing effects were also substantiated by the histological findings (greater reduction in inflammation and rapid collagen deposition as well as neovascularisation) and western blotting (decreased expression of vascular endothelial growth factor and transforming growth factor-β1 in group MC on day 14 after skin excision, unlike group Con). This study showed that, in addition to having wound healing effects, MC is biodegradable and non-toxic and can, therefore, be used as a dressing and scaffold material.

The Protective Effect of Apamin on LPS/Fat-Induced Atherosclerotic Mice

Apamin, a peptide component of bee venom (BV), has anti-inflammatory properties. However, the molecular mechanisms by which apamin prevents atherosclerosis are not fully understood. We examined the effect of apamin on atherosclerotic mice. Atherosclerotic mice received intraperitoneal (ip) injections of lipopolysaccharide (LPS, 2 mg/kg) to induce atherosclerotic change and were fed an atherogenic diet for 12 weeks. Apamin (0.05 mg/kg) was administered by ip injection. LPS-induced THP-1-derived macrophage inflammation treated with apamin reduced expression of tumor necrosis factor (TNF)-α, vascular cell adhesion molecule (VCAM)-1, and intracellular cell adhesion molecule (ICAM)-1, as well as the nuclear factor kappa B (NF-κB) signaling pathway. Apamin decreased the formation of atherosclerotic lesions as assessed by hematoxylin and elastic staining. Treatment with apamin reduced lipids, Ca(2+) levels, and TNF-α in the serum from atherosclerotic mice. Further, apamin significantly attenuated expression of VCAM-1, ICAM-1, TGF-β1, and fibronectin in the descending aorta from atherosclerotic mice. These results indicate that apamin plays an important role in monocyte/macrophage inflammatory processing and may be of potential value for preventing atherosclerosis.

Protective effect of melittin on inflammation and apoptosis in acute liver failure

Acute hepatic failure remains an extremely poor prognosis and still results in high mortality. Therefore, better treatment is urgently needed. Melittin, a major component of bee venom, is known to inhibit inflammatory reactions induced by lipopolysaccharide (LPS) or tumor necrosis factor (TNF)-α in various cell types. However, there is no evidence of the anti-inflammatory and anti-apoptotic effect of melittin on liver cells. In the present study, we investigated the effects of melittin on D: -galactosamine (GalN)/lipopolysaccharide (LPS)-induced acute hepatic failure. Acute liver injury was induced with GalN/LPS to determine in vivo efficacy of melittin. Mice were randomly divided into four groups: sterile saline treated group (NC), melittin only treated group (NM), GalN/LPS-treated group (GalN/LPS), and GalN/LPS treated with melittin group (M+GalN/LPS). Mice were given intraperitoneal GalN/LPS with or without melittin treatment. Liver injury was assessed biochemically and histologically. Inflammatory cytokines in the serum, apoptosis of hepatocytes, and cleavage of caspase-3 in the liver were determined. The expression of TNF-α and interleukin (IL)-1β were increased in the GalN/LPS group. However, treatment of melittin attenuated the increase of inflammatory cytokines. The M+GalN/LPS group showed significantly fewer apoptotic cells compared to the GalN/LPS group. Melittin significantly inhibited the expression of caspase and bax protein levels as well as cytochrome c release in vivo. In addition, melittin prevented the activation of the transcription factor nuclear factor-kappa B (NF-κB) induced by GalN/LPS. These results clearly indicate that melittin provided protection against GalN/LPS-induced acute hepatic failure through the inhibition of inflammatory cytokines and apoptosis.

Melittin inhibits atherosclerosis in LPS/high-fat treated mice through atheroprotective actions

AIM

Atherosclerosis is influenced by multiple environmental factors that involve a complex interaction between blood components and the arterial wall and is characterized by inflammatory reactions. Melittin has been used in treatment of various chronic inflammatory diseases. We investigated the effects of melittin regulated atherosclerotic changes in an animal model of atherosclerosis.

METHODS

Atherosclerotic mice were induced by intraperitoneal (i.p) injection of lipopolysaccharide (LPS, 2 mg/kg) three times a week and an atherogenic diet for 12 weeks.

RESULTS

Melittin (0.1 mg/kg) treatment was administered with i.p injection. Melittin treatment showed that total cholesterol and triglyceride levels decreased in atherosclerotic mice however, high-density lipoprotein cholesterol (HDL-C) levels were higher in atherosclerotic mice treated with melittin than in atherosclerotic mice. H&E staining showed that heart and descending aorta were significantly recovered by melittin, compared to atherosclerotic mice. In addition, melittin decreased the expression levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule (ICAM)-1, fibronectin and transforming growth factor (TGF)-β1 in atherosclerotic mice. In vitro, melittin decreased LPS-induced THP-1 cells-derived macrophages TNF-α and IL-1β expression levels and nuclear factor (NF)-κB signal pathway.

CONCLUSIONS

These results demonstrate that melittin has an anti-atherogenic effect by suppression of pro-inflammatory cytokines and adhesion molecules.

Melittin attenuates liver injury in thioacetamide-treated mice through modulating inflammation and fibrogenesis

Liver fibrosis represents a process of healing and scarring in response to chronic liver injury. Following injury, an acute inflammation response takes place resulting in moderate cell necrosis and extracellular matrix damage. Melittin, the major bioactive component in the venom of honey bee Apis mellifera, is a 26-residue amphipathic peptide with well-known cytolytic, antimicrobial and proinflammatory properties. However, the molecular mechanisms responsible for the anti-inflammatory activity of melittin have not been elucidated in liver fibrosis. We investigated whether melittin ameliorates liver inflammation and fibrosis in thioacetamide (TAA)-induced liver fibrosis. Two groups of mice were treated with TAA (200 mg/L, in drinking water), one of the groups of mice was co-treated with melittin (0.1 mg/kg) for 12 weeks while the other was not. Hepatic stellate cells (HSCs) were cultured with tumor necrosis factor α in the absence or presence of melittin. Melittin suppresses the expression of proinflammatory cytokines through the nuclear factor (NF)- κB signaling pathway. Moreover, melittin reduces the activity of HSCs in vitro, and decreases the expression of fibrotic gene responses in TAA-induced liver fibrosis. Taken together, melittin prevents TAA-induced liver fibrosis by inhibiting liver inflammation and fibrosis, the mechanism of which is the interruption of the NF- κB signaling pathway. These results suggest that melittin could be an effective agent for preventing liver fibrosis.

Ascochlorin suppresses TGF-β1-induced PAI-1 expression through the inhibition of phospho-EGFR in rat kidney fibroblast cells

Fibrosis is induced by the excessive and abnormal deposition of extracellular matrix (ECM) with various growth factors in tissues. Transforming growth factor-β1 (TGF-β1), the growth factor involved in fibrosis, modulates ECM synthesis and accumulation. TGF-β1 enhances the production of stimulators of ECM synthesis such as plasminogen activator inhibitor type 1 (PAI-1). As such, PAI-1 expression directly influences the proteolysis, invasion, and accumulation of ECM. It was shown in this study that ascochlorin, a prenylpenl antiobiotic, prevents the expression of profibrotic factors, such as PAI-1 and collagen type I, and that the TGF-β1-induced PAI-1 promoter activity is inhibited by ascochlorin. Ascochlorin abolishes the phosphorylation of the EGFR-MEK-ERK signaling pathway to regulate the TGF-β1-induced expression of PAI-1 without the inhibition of TβRII phosphorylation. Furthermore, the MEK inhibitor and EGFR siRNA block PAI-1 expression, and the Raf-1, MEK, and ERK signaling pathways for the regulation of PAI-1 expression. Ascochlorin suppresses the matrix metalloproteinases (MMPs) activity to activate the heparin-binding EGF-like growth factor (HB-EGF), to induce the phosphorylation of EGFR, and the MMPs inhibitor suppresses EGFR phosphorylation and the PAI-1 mRNA levels. These results suggest that ascochlorin prevents the expression of PAI-1 via the inhibition of an EGFR-dependent signal transduction pathway activated by MMPs.

Protective effects of melittin on transforming growth factor-β1 injury to hepatocytes via anti-apoptotic mechanism

Melittin is a cationic, hemolytic peptide that is the main toxic component in the venom of the honey bee (Apis mellifera). Melittin has multiple effects, including anti-bacterial, anti-viral and anti-inflammatory, in various cell types. However, the anti-apoptotic mechanisms of melittin have not been fully elucidated in hepatocytes. Apoptosis contributes to liver inflammation and fibrosis. Knowledge of the apoptotic mechanisms is important to develop new and effective therapies for treatment of cirrhosis, portal hypertension, liver cancer, and other liver diseases. In the present study, we investigated the anti-apoptotic effect of melittin on transforming growth factor (TGF)-β1-induced apoptosis in hepatocytes. TGF-β1-treated hepatocytes were exposed to low doses (0.5 and 1 μg/mL) and high dose (2 μg/mL) of melittin. The low doses significantly protected these cells from DNA damage in TGF-β1-induced apoptosis compared to the high dose. Also, melittin suppressed TGF-β1-induced apoptotic activation of the Bcl-2 family and caspase family of proteins, which resulted in the inhibition of poly-ADP-ribose polymerase (PARP) cleavage. These results demonstrate that TGF-β1 induces hepatocyte apoptosis and that an optimal dose of melittin exerts anti-apoptotic effects against TGF-β1-induced injury to hepatocytes via the mitochondrial pathway. These results suggest that an optimal dose of melittin can serve to protect cells against TGF-β1-mediated injury.

Effect of NF-κB decoy oligodeoxynucleotide on LPS/high-fat diet-induced atherosclerosis in an animal model

Atherosclerosis is a chronic inflammatory process occurring in the walls of arteries, in large part due to the accumulation of inflammatory cells. This study was conducted to determine the effect of nuclear factor (NF)-κB decoy oligodeoxynucleotide (ODN) in an atherosclerosis animal model. The mice received i.p. injections of lipopolysaccharide (LPS, 2 mg/kg) three times a week to induce atherosclerotic change, and fed an atherogenic diet for 12 weeks. NF-κB decoy ODN (0.4 mg/kg) was injected into the tail vein. Treatment with NF-κB decoy ODN decreased pro-inflammatory cytokines, tumour necrosis factor (TNF)-α and interleukin (IL)-1β and inflammatory markers, vascular adhesion molecule (VCAM)-1 and intercellular adhesion molecule (ICAM)-1, in the LPS/Fat-induced mice. In addition, the expression of proteins related to fibrosis, transforming growth factor (TGF)-β1 and fibronectin were markedly decreased in the mice treated with NF-κB decoy ODN compared with the LPS/Fat-induced mice without decoy ODN treatment. These data suggest that NF-κB decoy ODN may exert an inhibitory effect on the expression levels of pro-inflammatory cytokines and cell adhesion molecules in atherosclerotic mice.

Melittin enhances apoptosis through suppression of IL-6/sIL-6R complex-induced NF-κB and STAT3 activation and Bcl-2 expression for human fibroblast-like synoviocytes in rheumatoid arthritis

OBJECTIVE

Resistance to apoptosis of fibroblast-like synoviocytes (FLS) is considered as a major characteristic in RA. This study was designed to identify whether melittin has a pro-apoptotic effect in IL-6/sIL6R-stimulated human FLS by investigating the expression of mitochondrial apoptosis-related genes, nuclear factor-κB (NF-κB), and signal transducer and activators of transcription (STAT) activation.

METHODS

Cell viability was determined using a MTT assay after melittin treatment. Expressions of STAT3 and mitochondrial apoptosis-related genes induced by the IL-6/sIL-6R complex were determined by real time-polymerase chain reaction and western blotting. The expression of NF-κB p65 following IL-6 stimulation was determined by western blot analysis. The effects of melittin on the expression of apoptosis-related genes and the transcription factors NF-κB p65 and STAT3 were assessed in FLS. Apoptosis of FLS was determined by TUNEL-labeling to detect DNA strand breaks and DNA fragmentation assays. Caspase-3 activity was determined by a colorimetric assay.

RESULTS

IL-6/sIL-6R induced the activation of the transcription factors, STAT3, NF-κB p65 (nucleus), and Bcl-2. Melittin increased the expression of pro-apoptosis-related molecules, namely caspase-3, caspase-9, Apaf-1, and cytosolic cytochrome c, in a dose-dependent manner after treatment with IL-6/sIL-6R. Melittin inhibited STAT3 activation, translocation of NF-κB p65 into the nucleus, and expression of anti-apoptotic genes such as Bcl-2 and mitochondrial cytochrome c.

CONCLUSIONS

The pro-apoptotic effects of melittin likely result from inhibition of the activation of the transcription factors, STAT3 and NF-κB p65, and regulation of mitochondrial apoptosis-related genes. Melittin is thus a promising therapeutic option for RA as it induces apoptosis in apoptosis-resistant synoviocytes.

4-O-methylascochlorin, methylated derivative of ascochlorin, stabilizes HIF-1α via AMPK activation

Chemopreventive or anticancer agents induce cancer cells to apoptosis through the activation of adenosine AMP-activated protein kinase (AMPK), which plays a major role as energy sensors under ATP-deprived condition or ROS generation. In this study, we compared the effects of ascochlorin (ASC), from the fungus Ascochyta viciae, and its derivatives on AMPK activity. We also examined a regulatory mechanism for hypoxia-inducible factor-1α (HIF-1α) stabilization in response to 4-O-methylascochlorin (MAC). We found that AMPK activation was mainly involved with MAC, but not ASC and 4-O-carboxymethylascochlorin (AS-6), indicating that the substitution of 4-O-methyl group from 4-O-hydroxyl group of ASC is important in the activation of AMPK and the expression of HIF-1α. MAC-stabilized HIF-1α via AMPK activation triggered by lowering the intracellular ATP level, not by ROS generation, increases glucose uptake and the expression of vascular endothelial growth factor (VEGF) and glucose transporter 1 (GLUT-1), major target genes of HIF-1α. Moreover, MAC-induced AMPK activity suppressed survival factors, including mTOR and ERK1/2 or translational regulators, including p70S6K and 4E-BP1. Our data suggest that AMPK is a key determinant of MAC-induced HIF-1α expression in response to energy stress, further implying its involvement in MAC-induced apoptosis.

Biological effects of treatment of an animal skin wound with honeybee (Apis mellifera. L) venom

BACKGROUND

Wound healing is a dynamic and complex process of tissue repair, which involves a number of cellular and molecular events. It progresses from an inflammatory response to re-epithelialisation and, finally, to the formation of a permanent scar. The pharmacological activities of honeybee (Apis mellifera L.) venom (BV) have been used in wound healing for centuries.

METHODS

To study wound healing, full-thickness skin defects were produced on the dorsal area of mice. We measured the relative sizes and conducted histological assays of the wounds on days 3, 5 and 7. The expressions of transforming growth factor (TGF)-β1, fibronectin, vascular endothelial growth factor (VEGF) and collagen-I mRNA in the wound healing area was measured by reverse transcription polymerase chain reaction (RT-PCR). The amount of TGF-β1, fibronectin, VEGF and collagen-I was determined using immunohistochemical staining.

RESULTS

The wound sizes were small in the BV group compared with the control and Vaseline groups. The BV group demonstrated decreased TGF-β1, fibronectin and VEGF mRNA levels and increased collagen-I mRNA levels. The expressions of TGF-β1, fibronectin and VEGF proteins were significantly lower in the BV group compared with the control group, while the expression of collagen-I was increased in the BV group as indicated by immunohistochemical staining.

CONCLUSION

These data suggested that BV had significant wound-healing activity. The results from this study indicated that the effects of BV on wound healing may involve biological mechanisms associated with the expressions of TGF-β1, fibronectin, VEGF and collagen-I.

p53-independent induction of G1 arrest and p21WAF1/CIP1 expression by ascofuranone, an isoprenoid antibiotic, through downregulation of c-Myc

Ascofuranone has been shown to have antitumor activity, but the precise molecular mechanism by which it inhibits the proliferation of cancer cells remains unclear. Here, we study the effects of ascofuranone on cell cycle progression in human cancer cells and find that ascofuranone induces G(1) arrest without cytoxicity with upregulation of p53 and p21(WAF1/CIP1) while downregulating c-Myc and G(1) cyclins. Chromatin immunoprecipitation assay and RNA interference studies with cells deficient in p53 and p21 show that ascofuranone induces p21(WAF1/CIP1) expression and subsequent G(1) arrest through the release of p21(WAF1/CIP1) promoter from c-Myc-mediated transcriptional repression, independent of p53. Ascofuranone-induced p21(WAF1/CIP1) associates with CDK2 and prevents CDK2-cyclin E complex formation, leading to the inactivation of E2F transcriptional activity. These results suggest that ascofuranone upregulates p21(WAF1/CIP1) through p53-independent suppression of c-Myc expression, leading to cytostatic G(1) arrest. Thus, ascofuranone represents a unique natural antitumor compound that targets c-Myc independent of p53.

The protective effect of bee venom against ethanol-induced hepatic injury via regulation of the mitochondria-related apoptotic pathway

Alcohol consumption increases apoptosis of hepatocytes. Death of hepatocytes is a characteristic feature of chronic liver disease for various causes. Bee venom (Apis mellifera) has been traditionally used for the treatment of various chronic diseases, such as chronic inflammatory arthritis and chronic liver disease. However, the precise mechanism for bee venom in chronic liver disease is not still cleared. To assess the effects of bee venom in chronic liver disease, we investigated the potential role of the bee venom in the ethanol-induced hepatocyte apoptosis. Bee venom treatment inhibited the apoptotic cell morphology and increased the cell viability in ethanol-induced hepatocyte apoptosis. With ethanol treatment, bee venom-treated hepatocytes increased activity of Bcl-2 and Bcl-xL, reduced activity of Bax, Caspase and PARP. In conclusion, bee venom treatment in ethanol-induced hepatocyte apoptosis occurred through the regulation of Bcl family with subsequent inactivation of the Caspase and PARP. These results suggest that bee venom could be an effective agent to reduce ethanol-induced hepatocyte apoptosis.

Melittin suppresses PMA-induced tumor cell invasion by inhibiting NF-kappaB and AP-1-dependent MMP-9 expression

Matrix metalloproteinase-9 (MMP-9) plays an important role in the invasion and metastasis of cancer cells. In this study, we examined the inhibitory effect of bee venom (BV) and its major peptides, melittin and apamin, on PMA-induced invasion induced by MMP-9 expression in Caki-1 renal cancer cells. BV and melittin, but not apamin, significantly suppressed PMA-induced invasion by inhibiting MMP-9 expression in Caki-1 cells. Furthermore, as evidenced by MMP-9 promoter assays, melittin inhibited MMP-9 gene expression by blocking the PMA-stimulated activations of activator protein-1 (AP-1) and nuclear factor-kappa B (NF-kappaB). In addition, melittin suppressed the PMA-induced phosphorylations of ERK and JNK mitogen-activated protein kinases, upstream factors involved in Ap-1 and NF-kappaB. These results suggest that the suppression of MMP-9 expression contributes to the anti-tumor properties of melittin.

Bee venom protects hepatocytes from tumor necrosis factor-alpha and actinomycin D

Honeybee (Apis mellifera) venom (BV) has a broad array of therapeutic applications in traditional medicine to treat variety of diseases. It is also known that BV possesses anti-inflammatory and anticancer effect and that it can inhibit proliferation and induces apoptosis in cancer cells, but there is no evidence of information regarding anti-apoptosis of BV on hepatocytes. In the present study, we investigated the anti-apoptotic effect of BV on tumor necrosis factor (TNF)-alpha with actinomycin (Act) D induces apoptosis in hepatocytes. TNF-alpha/Act D-treated hepatocytes were exposed to different low concentration (1, 10 and 100 ng/mL) of BV. Our results showed statistically significant inhibition in DNA damage caused by BV treatment compared to corresponding TNF-alpha/Act D-treated hepatocytes. BV suppressed TNF-alpha/Act Dtreated activation of bcl-2 family and caspase family, which resulted in inhibition of cytochrome c release and PARP cleavage. These results demonstrate that low concentration BV possess a potent suppressive effect on anti-apoptotic responses of TNF-alpha/Act D-treated hepatocytes and suggest that these compounds may contribute substantial therapeutic potential for the treatment of liver diseases.

Bee venom suppresses PMA-mediated MMP-9 gene activation via JNK/p38 and NF-kappaB-dependent mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Bee venom has been used for the treatment of inflammatory diseases such as rheumatoid arthritis and for the relief of pain in traditional oriental medicine.

AIM OF THE STUDY

The purpose of this study is to elucidate the effects of bee venom on MMP-9 expression and determine possible mechanisms by which bee venom relieves or prevents the expression of MMP-9 during invasion and metastasis of breast cancer cells. We examined the expression and activity of MMP-9 and possible signaling pathway affected in PMA-induced MCF-7 cells.

MATERIAL AND METHODS

Bee venom was obtained from the National Institute of Agricultural Science and Technology of Korea. Matrigel invasion assay, wound-healing assay, zymography assay, western blot assay, electrophoretic mobility shift assay and luciferase gene assay were used for assessment.

RESULTS

Bee venom inhibited cell invasion and migration, and also suppressed MMP-9 activity and expression, processes related to tumor invasion and metastasis, in PMA-induced MCF-7 cells. Bee venom specifically suppressed the phosphorylation of p38/JNK and at the same time, suppressed the protein expression, DNA binding and promoter activity of NF-kappaB. The levels of phosphorylated ERK1/2 and c-Jun did not change. We also investigated MMP-9 inhibition by melittin, apamin and PLA(2), representative single component of bee venom. We confirmed that PMA-induced MMP-9 activity was significantly decreased by melittin, but not by apamin and phospholipase A(2). These data demonstrated that the expression of MMP-9 was abolished by melittin, the main component of bee venom.

CONCLUSION

Bee venom inhibits PMA-induced MMP-9 expression and activity by inhibition of NF-kappaB via p38 MAPK and JNK signaling pathways in MCF-7 cells. These results indicate that bee venom can be a potential anti-metastatic and anti-invasive agent. This useful effect may lead to future clinical research on the anti-cancer properties of bee venom.

Bee Venom Inhibits Hepatic Fibrosis Through Suppression of Pro-Fibrogenic Cytokine Expression

Bee venom (BV) has a long tradition of use for the control of pain and inflammation in various chronic diseases. Carbon tetrachloride ( CCl4) is known to induce hepatotoxicity after being metabolized to the highly reactive trichloromethyl free radical and its peroxy radical. The purpose of the current study was to examine whether BV regulates the pro-inflammation and fibrosis related genes against a mouse model of hepatic fibrosis induced by CCl4and ethanol-treated hepatocytes (ETH). Test mice were administered with CCl4(2 ml/mg) and hepatocytes were treated with 25 mM ethanol. BV was added to the final concentration of 0.05–0.5 mg/kg and 1–100 ng/ml for in vivo and in vitro testing, respectively. Fibrotic livers and ETH were used for the measurement of hepatocyte necrosis, pro-inflammatory cytokines and fibrogenic genes. BV suppressed CCl4-induced hepatocyte necrosis markers of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). It also inhibited the secretion of interleukin (IL)-1β and tumor necrosis factor (TNF)-α. Moreover, BV inhibited CCl4-induced expression of transforming growth factor (TGF)-β1, α-smooth muscle actin (SMA) and fibronectin. Similarly, ETH exhibited significant suppression of IL-1β, TNF-α, TGF-β1 and fibronectin when cultured with BV. These results suggest that BV possesses anti-fibrogenic properties that are mediated by the suppression of pro-inflammatory cytokines and fibrogenic gene expression. BV has substantial therapeutic potential for the treatment of fibrotic diseases.

Bee Venom Reduces Atherosclerotic Lesion Formation via Anti-Inflammatory Mechanism

The components of bee venom (BV) utilized in the current study were carefully scrutinized with chromatography. Despite its well documented anti-inflammatory property, there are no reports regarding the influence of BV on the expression of cellular adhesion molecules in the vascular endothelium. A great amount of information exists concerning the effects of an atherogenic diet on atherosclerotic changes in the aorta, but little is known about the molecular mechanisms and the levels of gene regulation involved in the anti-inflammatory process induced by BV. The experimental atherosclerosis was induced in mice by a lipopolysaccharide (LPS) injection and an atherogenic diet. The animals were divided into three groups, the NC groups of animals that were fed with a normal diet, the LPS/fat group was fed with the atherogenic diet and received intraperitoneal injections of LPS, and the LPS/fat + BV group was given LPS, an atherogenic diet and intraperitoneal BV injections. At the end of each treatment period, the LPS/fat + BV group had decreased levels of total cholesterol (TC) and triglyceride (TG) in their serum, compared to the LPS/fat group. The LPS/fat group had significant expression of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in the serum, compared with the NC group ( p < 0.05). The amount of cytokines reduced consistently in the BV treatment groups compared with those in LPS/fat group. BV significantly reduced the amount of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), transforming growth factor-β1 (TGF-β1) and fibronectin in the aorta, compared with the LPS/fat group ( p < 0.05). A similar pattern was also observed in the heart. In conclusion, BV has anti-atherogenic properties via its lipid-lowering and anti-inflammatory mechanisms.