Bisdemethoxycurcumin Reduces Methicillin-Resistant Staphylococcus aureus Expression of Virulence-Related Exoproteins and Inhibits the Biofilm Formation.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen of nosocomial infection, which is resistant to most antibiotics. Presently, anti-virulence therapy and anti-biofilm therapy are considered to be promising alternatives. In the current work, we investigated the influence of bisdemethoxycurcumin (BDMC) on the virulence-related exoproteins and the biofilm formation using a reference strain and clinic isolated strains. Western blotting, quantitative RT-PCR, and tumor necrosis factor (TNF) release assay were performed to assess the efficacy of BDMC in reducing the expression of Staphylococcus enterotoxin-related exoproteins (enterotoxin A, enterotoxin B) and α-toxin in MRSA. The anti-biofilm activity of BDMC was evaluated through a biofilm inhibition assay. The study suggests that sub-inhibitory concentrations of BDMC significantly inhibited the expression of sea, seb, and hla at the mRNA level in MRSA. Moreover, the expression of virulence-related exoproteins was significantly decreased by down-regulating accessory gene regulator agr, and the inhibition of biofilms formation was demonstrated by BDMC at sub-inhibitory concentrations. Consequently, the study suggests that BDMC may be a potential natural antibacterial agent to release the pressure brought by antibiotic resistance.

Eleutheroside K Isolated from Acanthopanax henryi (Oliv.) Harms Inhibits the Expression of Virulence-Related Exoproteins in Methicillin-Resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus (S.) aureus (MRSA) is a representative pathogen that produces numerous virulence factors involving manifold cytotoxins and exotoxins. The present study was designed to investigate the influence of Eleutheroside K (ETSK), a single compound isolated from the leaves of Acanthopanax (A.) henryi (Oliv.) Harms, on the exotoxins secreted by MRSA. The transcription and translation of the exotoxins (α-hemolysin and staphylococcal enterotoxins) related to virulence in S. aureus were determined via quantitative RT-PCR and western blot analysis. The effect of ETSK on the production of tumor necrosis factor (TNF)-α was evaluated using enzyme-linked immunosorbent assay. As a result, ETSK at sub-MIC concentrations could reduce the protein expression of α-hemolysin and enterotoxin, and the expression of genes that regulate virulence factors was also inhibited. In addition, the TNF-inducing activity of S. aureus was attenuated by ETSK in a dose-dependent manner. These results revealed that ETSK not only reduced the protein and gene expression levels of related exotoxins but also suppressed the ability of S. aureus to induce macrophages to release cytokines. This study indicated that the inhibition of MRSA infection by ETSK may be achieved by reducing the virulence of S. aureus and highlighted the potential of ETSK as an innovative strategy for the prevention and treatment of MRSA infections.

Cryptotanshinone Induces Cell Cycle Arrest and Apoptosis of NSCLC Cells through the PI3K/Akt/GSK-3ß Pathway.

Cryptotanshinone (CTT) is a natural product and a quinoid diterpene isolated from the root of the Asian medicinal plant, Salvia miltiorrhizabunge. Notably, CTT has a variety of anti-cancer actions, including the activation of apoptosis, anti-proliferation, and reduction in angiogenesis. We further investigated the anti-cancer effects of CTT using MTS, LDH, and Annexin V assay, DAPI staining, cell cycle arrest, and Western blot analysis in NSCLC cell lines. NSCLC cells treated with CTT reduced cell growth through PI3K/Akt/GSK3ß pathway inhibition, G0/G1 cell cycle arrest, and the activation of apoptosis. CTT induced an increase of caspase-3, caspase-9, poly-ADP-ribose polymerase (PARP), and Bax, as well as inhibition of Bcl-2, survivin, and cellular-inhibitor of apoptosis protein 1 and 2 (cIAP-1 and -2). It also induced G0/G1 phase cell cycle arrest by decreasing the expression of the cyclin A, cyclin D, cyclin E, Cdk 2, and Cdk 4. These results highlight anti-proliferation the latent of CTT as natural therapeutic agent for NSCLC. Therefore, we investigated the possibility of CTT as an anti-cancer agent by comparing with GF, which is a representative anti-cancer drug.

Polygalacin D induces apoptosis and cell cycle arrest via the PI3K/Akt pathway in non-small cell lung cancer.

Polygalacin D (PGD) is a bioactive compound isolated from Platycodon grandiflorum (Jacq.) and it has a similar structure to platycodin D, which is a well known anticancer agent. In the present study, we investigated the anti-proliferative effects of PGD using NSCLC cell lines. We evaluated the effects of PGD on proliferation, apoptosis and cell cycle arrest in A549 and H460 cells. PGD significantly induced apoptosis and nuclear condensation in both cell lines. Furthermore, PGD upregulated the cleavage of apoptotic proteins such as caspase-3, -9 and PARP. Additionally, treatment with PGD suppressed the expression of the IAP family of proteins including survivin, cIAP-1 and cIAP-2. Furthermore, PGD induced G0/G1-phase arrest in both cell lines. After treatment with PGD, the expression of TIMP-1, CDK2, cyclin A and cyclin E was reduced at the protein level. In addition, PGD blocked the PI3K/Akt pathway by inhibiting the phosphorylation of GSK3ß, Akt and the expression of PI3K. Our results indicated that the anti-proliferative properties of PGD may result from the regulation of the PI3K/Akt pathway, which plays a critical role in cell survival and growth.

MAPKs and NF­κB pathway inhibitory effect of bisdemethoxycurcumin on phorbol­12­myristate­13­acetate and A23187­induced inflammation in human mast cells.

Inflammation­associated damage may occur in any tissue following infection, exposure to toxins, following ischemia, and in allergic and auto­immune reactions. Inflammation may also result from mast cell degranulation induced by the intracellular calcium concentration. The inflammatory process may be inhibited by compounds that affect mast cells. Bisdemethoxycurcumin [1,7­bis(4­hydroxyphenyl) hepta­1,6­diene­3,5­dione, BDCM] is the active component of turmeric. It has anticancer, antioxidant and antibacterial properties. To investigate the molecular mechanism associated with the anti­inflammatory activity of BDCM, human mast cell line 1 (HMC­1) cells were treated with phorbol­12­myristate­13­acetate (PMA) and calcium ionophore A23187 (A23187) to induce the inflammatory process. Various HMC­1 cells were pretreated with BDCM prior to stimulation of inflammation. BDCM inhibited the inflammation­triggered production of cytokines including interleukin (IL)­6, IL­8, and tumor necrosis factor (TNF)­α. BDCM inhibition extended to the gene level. In activated HMC­1 cells, phosphorylation levels of extracellular signal­regulated kinase, c­jun N­terminal kinase and p38 mitogen­activated protein kinase were decreased by treatment with BDCM. BDCM also inhibited nuclear factor­(NF)­κB activation and IκB degradation. In conclusion, BDCM suppresses the expression of TNF­α, IL­8, and IL­6 by inhibiting the NF­κB and mitogen activated protein kinase signaling pathways.

Araliasaponin II isolated from leaves of Acanthopanax henryi (Oliv.) Harms inhibits inflammation by modulating the expression of inflammatory markers in murine macrophages.

Araliasaponin II (AS II) is a bioactive compound isolated from Acanthopanax henryi (Oliv.) Harms, a plant widely used in traditional oriental medicine. The present study investigated the anti­inflammatory effects of AS II using murine macrophages. The effects of AS II on inflammatory mediator and cytokine production in lipopolysaccharide (LPS)­stimulated RAW 264.7 cells was evaluated. Nitric oxide (NO) and cytokine production were determined using the Griess reagent and an ELISA kit. The expression levels of cytokines, inducible NO synthase (iNOS) and cyclooxygenase­2 (COX­2) mRNA were examined by reverse transcription­quantitative polymerase chain reaction. The expression levels of iNOS, COX­2 and toll­like receptor (TLR)­4 protein were examined by western blotting. Translocation of nuclear factor­κB (NF­κB) and TLR­4 expression were visualized by immunofluorescence staining. AS II markedly inhibited the production of NO and prostaglandin E2, and reduced iNOS and COX­2 expression at the transcriptional and translational levels. AS II downregulated the expression of interleukin­6 and tumor necrosis factor­α at the protein and mRNA levels. Furthermore, pre­treatment with AS II significantly suppressed the TLR­4­NF­κB signaling pathway; this effect may be cause by AS II competing with LPS for binding to TLR­4 and subsequently inhibiting translocation of the NF­κB/p65 protein to the nucleus. The results suggested that the anti­inflammatory properties of AS II may result from inhibiting pro­inflammatory mediators by suppressing the initiation of the inflammatory response and inhibiting TLR-4-NF-κB signaling pathways.

Subinhibitory concentrations of punicalagin reduces expression of virulence-related exoproteins by Staphylococcus aureus.

Staphylococcus aureus produces a number of virulence factors. The major virulence factors exhibited by S aureus include various antigens, enzymes, cytotoxins and exotoxins (e.g. hemolysins, enterotoxins and toxic shock syndrome toxin). In this report, we show the influence of punicalagin on the secretion of exoprotein from S aureus by western blotting, tumor necrosis factor (TNF) release assay and quantitative RT-PCR. When added to S aureus cultures at an OD600 of 0.9, graded subinhibitory concentrations of punicalagin reduced the production of α-toxin, SEA and SEB in methicillin-resistant Staphylococcus aureus in a dose-dependent manner. Consistently, punicalagin reduced TNF-inducing activity by S aureus culture supernatants. Here, the transcriptional level of agr (accessory gene regulator) in S aureus was inhibited by punicalagin, suggesting that the reduced transcription may affect the secretion of exotoxins. These findings suggest that the expression of α-toxin and enterotoxins in S aureus is sensitive to the action of punicalagin, which may be an advantageous candidate in the treatment of toxigenic staphylococcal disease.

Anti-inflammatory effect of salidroside on phorbol-12-myristate-13-acetate plus A23187-mediated inflammation in HMC-1 cells.

Salidroside [2-(4-hydroxyphenyl)ethyl ß-D-gluco-pyranoside (SAS)] has been identified as the most potent ingredient of the plant Rhodiola rosea L. Previous studies have demonstrated that it possesses a number of pharmacological properties, including anti-aging, anti-fatigue, antioxidant, anticancer and anti-inflammatory properties. In this study, to ascertain the molecular mechanisms responsible for the anti-inflammatory activity of SAS, we used phorbol-12-myristate-13-acetate (PMA) plus A23187 to induce inflammation in human mast cell line-1 (HMC-1). The HMC-1 cells were treated with SAS prior to being stimulated with PMA plus A23187. Pro-inflammatory cytokine production was measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR). Western blot analysis was used to examine the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB). SAS inhibited the mRNA expression and production of interleukin (IL)-6, IL-8 and tumor necrosis factor (TNF). In cells stimulated with PMA plus A23187, SAS suppressed the phosphorylation of extracellular signal-regulated kinase (ERK)1/2 and c-jun N-terminal kinase 1/2 (JNK1/2), but not that of p38 MAPK. SAS suppressed the expression of NF-κB in the nucleus. On the whole, our results suggest that SAS exerts an anti-inflammatory effect by inhibiting the production of pro-inflammatory cytokines through the blocking of the NF-κB and MAPK signaling pathways.

Anti­inflammatory effects of Ciwujianoside C3, extracted from the leaves of Acanthopanax henryi (Oliv.) Harms, on LPS­stimulated RAW 264.7 cells.

The present study aimed to investigate the unknown mechanisms underlying the anti­inflammatory activity of Ciwujianoside C3 (CJS C3), extracted from the leaves of Acanthopanax henryi Harms, on lipopolysaccharide (LPS)­stimulated RAW 264.7 cells. Cells were treated with CJS C3 for 1 h prior to the addition of 200 ng/ml LPS. Cell viability was measured using the MTS assay. Nitric oxide levels were determined by Griess assay. Proinflammatory cytokine production was measured by enzyme­linked immunosorbent assay. The expression levels of cyclooxygenase (COX)­2, inducible nitric oxide synthase (iNOS), and mitogen­activated protein kinases (MAPKs) were investigated by western blotting, reverse transcription (RT)­polymerase chain reaction (PCR) and RT­quantitative PCR. Nuclear factor (NF)­κB/p65 localization, and interaction of the TLR4 receptor with LPS was examined by immunofluorescence assay. The results indicated that CJS C3 exhibited no cytotoxicity at the measured concentrations. Treatment with CJS C3 inhibited NO production, proinflammatory cytokine levels, including interleukin (IL)­6, tumor necrosis factor (TNF)­α, and prostaglandin E2 (PGE2), and protein and mRNA expression levels of iNOS and COX­2. Furthermore, CJS C3 suppressed phosphorylation of extracellular signal­regulated kinases and c­jun N­terminal kinases. It was also able to suppress activation of NF­κB via inhibition of the TLR4 signaling pathway. These results suggested that CJS C3 exerts inhibitory effects on LPS­induced PGE2, NO, IL­6 and TNF­α production. In addition, iNOS and COX­2 expression was decreased in murine macrophages. These inhibitory effects may be achieved via suppression of MAPKs and NF­κB phosphorylation following inhibition of the TLR4 signaling pathway.

Luteolin potentiates the effects of aminoglycoside and ß-lactam antibiotics against methicillin-resistant Staphylococcus aureus in vitro.

Methicillin-resistant Staphylococcus aureus (MRSA) infection has become a serious clinical problem worldwide, and alternative natural or combination drug therapies are required for its treatment. The aim of the present study was to examined the antimicrobial activity of luteolin (LUT) against MRSA. Luteolin is a polyphenolic flavonoid compound with a wide spectrum of biological activities. The antimicrobial activities of LUT and the antibiotics ampicillin (AM), oxacillin (OX) and gentamicin (GT), used alone or in combination, were evaluated against five clinical MRSA isolates and two reference strains using a minimum inhibitory concentration (MIC) assay, MTT colorimetric assay, checkerboard dilution test and time-kill assay. The MIC of LUT against all strains was found to be 62.5 µg/ml. The combinations of LUT and antibiotics exhibited a synergistic effect against MRSA in the majority of cases, as determined by the checkerboard method. Time-kill curves revealed that a combination of LUT with AM, OX or GT significantly reduced bacterial counts, which dropped below the lowest detectable limit after 24 h. These results indicate that LUT potentiates the effects of ß-lactam and aminoglycoside antibiotics against MRSA.

Hepatoprotective Effect and Synergism of Bisdemethoycurcumin against MCD Diet-Induced Nonalcoholic Fatty Liver Disease in Mice.

Nonalcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome, has become one of the most common causes of chronic liver disease over the last decade in developed countries. NAFLD includes a spectrum of pathological hepatic changes, such as steatosis, steatohepatitis, advanced fibrosis, and cirrhosis. Bisdemethoxycurcumin (BDMC) is polyphenolic compounds with a diarylheptanoid skeleton, curcumin close analogues, which is derived from the Curcumae Longae Rhizoma. While the rich bioavailability research of curcumin, BDMC is the poor studies. We investigated whether BDMC has the hepatoprotective effect and combinatory preventive effect with silymarin on methionine choline deficient (MCD)-diet-induced NAFLD in C57BL/6J mice. C57BL/6J mice were divided into five groups of normal (normal diet without any treatment), MCD diet (MCD diet only), MCD + silymarin (SIL) 100 mg/kg group, MCD + BDMC 100 mg/kg group, MCD + SIL 50 mg/kg + BDMC 50 mg/kg group. Body weight, liver weight, liver function tests, histological changes were assessed and quantitative real-time polymerase chain reaction and Western blot analyses were conducted after 4 weeks. Mice lost body weight on the MCD-diet, but BDMC did not lose less than the MCD-diet group. Liver weights decreased from BDMC, but they increased significantly in the MCD-diet groups. All liver function test values decreased from the MCD-diet, whereas those from the BDMC increased significantly. The MCD- diet induced severe hepatic fatty accumulation, but the fatty change was reduced in the BDMC. The BDMC showed an inhibitory effect on liver lipogenesis by reducing associated gene expression caused by the MCD-diet. In all experiments, the combinations of BDMC with SIL had a synergistic effect against MCD-diet models. In conclusion, our findings indicate that BDMC has a potential suppressive effect on NAFLD. Therefore, our data suggest that BDMC may act as a novel and potent therapeutic agent against NAFLD.

The Mechanism Underlying the Antibacterial Activity of Shikonin against Methicillin-Resistant Staphylococcus aureus.

Shikonin (SKN), a highly liposoluble naphthoquinone pigment isolated from the roots of Lithospermum erythrorhizon, is known to exert antibacterial, wound-healing, anti-inflammatory, antithrombotic, and antitumor effects. The aim of this study was to examine SKN antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). The SKN was analyzed in combination with membrane-permeabilizing agents Tris and Triton X-100, ATPase inhibitors sodium azide and N,N'-dicyclohexylcarbodiimide, and S. aureus-derived peptidoglycan; the effects on MRSA viability were evaluated by the broth microdilution method, time-kill test, and transmission electron microscopy. Addition of membrane-permeabilizing agents or ATPase inhibitors together with a low dose of SKN potentiated SKN anti-MRSA activity, as evidenced by the reduction of MRSA cell density by 75% compared to that observed when SKN was used alone; in contrast, addition of peptidoglycan blocked the antibacterial activity of SKN. The results indicate that the anti-MRSA effect of SKN is associated with its affinity to peptidoglycan, the permeability of the cytoplasmic membrane, and the activity of ATP-binding cassette (ABC) transporters. This study revealed the potential of SKN as an effective natural antibiotic and of its possible use to substantially reduce the use of existing antibiotic may also be important for understanding the mechanism underlying the antibacterial activity of natural compounds.

Protective effect of ixerisoside A against UVB-induced pro-inflammatory cytokine production in human keratinocytes.

Human skin is the first line of defense for the protection of the internal organs of the body from different stimuli. Ultraviolet B (UVB), one of the harmful radiations for skin, is widely known to induce abnormally increased cytokine release from keratinocytes leading to inflammatory skin disorders. IL-6 and IL-8 induce an acute-phase response and stimulate leukocyte infiltration in the skin. Previous studies have shown that chronic exposure to UVB radiation increases cyclooxygenase-2 (COX­2) expression through various cell signaling pathways, resulting in skin cancer. Recent studies have shown that the activation of extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38 MAPK is strongly correlated with acute inflammation and development of skin cancer caused by an increased expression of COX-2. Ixerisoside A (IXA) is an active constituent of Ixeris dentata of the Compositae (Asteraceae) family. The effect of IXA on skin inflammation has yet to be elucidated. To determine the anti-inflammatory effects of IXA, we examined its effect on UVB-induced pro-inflammatory cytokine production in human keratinocytes (HaCaT cells) by observing these cells in the presence or absence of IXA. In this study, pro-inflammatory cytokine production was determined by enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (rt-pcr), and western blot analysis to evaluate the activation of mitogen-activated protein kinases (MAPKs). IXA inhibited UVB-induced production of the pro-inflammatory cytokines IL-6 and IL-8 in a dose-dependent manner. Moreover, IXA inhibited the expression of COX-2, ERK, JNK, and p38 MAPKs, indicating that the secretion of the pro-inflammatory cytokines IL-6 and IL-8, and COX-2 expression was inhibited by blocking MAPK phosphorylation. These results indicated that IXA potentially protects against UVB-induced skin inflammation.

Puerarin ameliorates hepatic steatosis by activating the PPARα and AMPK signaling pathways in hepatocytes.

Non-alcoholic fatty liver disease (NAFLD) is characterized by the hepatic manifestation of metabolic syndrome and is the leading cause of chronic liver disease. Steatohepatitis plays a critical role in the process resulting in liver fibrosis and cirrhosis. Puerarin is a herbal product widely used in Asia, and is believed to have therapeutic benefits for alleviating the symptoms of steatohepatitis. The present study was designed to investigate the effects and mechanisms of action of puerarin in reducing lipid accumulation in oleic acid (OA)-treated HepG2 cells. Hepatocytes were treated with OA with or without puerarin to observe lipid accumulation by Oil Red O staining. We also examined hepatic lipid contents (e.g., triacylglycerol and cholesterol) following treatment with puerarin. Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR) were used to measure sterol regulatory element binding protein (SREBP)-1, fatty acid synthase (FAS), peroxisome proliferator-activated receptor α (PPARα) and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) protein and mRNA expression, respectively. Our results revealed that puerarin suppressed OA-induced lipid accumulation, and reduced the triacylglycerol and cholesterol levels. Furthermore, puerarin decreased the expression levels of lipogenic enzymes, such as FAS and SREBPs, and increased the expression levels of PPARα, which are critical regulators of hepatic lipid metabolism through the AMPK signaling pathway. These results indicate that puerarin has the same ability to activate AMPK, and reduce SREBP-1 and FAS expression, thus inhibiting hepatic lipogenesis and increasing hepatic antioxidant activity. We found that puerarin exerted a regulatory effect on lipid accumulation by decreasing lipogenesis in hepatocytes. Therefore, puerarin extract may have therapeutic benefits in the treatment of fatty liver and lipid-related metabolic disorders.

Curcumin reverse methicillin resistance in Staphylococcus aureus.

Curcumin, a natural polyphenolic flavonoid extracted from the rhizome of Curcuma longa L., was shown to possess superior potency to resensitize methicillin-resistant Staphylococcus aureus (MRSA) to antibiotics. Previous studies have shown the synergistic activity of curcumin with ß-lactam and quinolone antibiotics. Further, to understand the anti-MRSA mechanism of curcumin, we investigated the potentiated effect of curcumin by its interaction in diverse conditions. The mechanism of anti-MRSA action of curcumin was analyzed by the viability assay in the presence of detergents, ATPase inhibitors and peptidoglycan (PGN) from S. aureus, and the PBP2a protein level was analyzed by western blotting. The morphological changes in the curcumin-treated MRSA strains were investigated by transmission electron microscopy (TEM). We analyzed increased susceptibility to MRSA isolates in the presence of curcumin. The optical densities at 600 nm (OD600) of the suspensions treated with the combinations of curcumin with triton X-100 and Tris were reduced to 63% and 59%, respectively, compared to curcumin without treatment. N,N'-dicyclohexylcarbodiimide (DCCD) and sodium azide (NaN3) were reduced to 94% and 55%, respectively. When peptidoglycan (PGN) from S. aureus was combined with curcumin, PGN (0-125 µg/mL) gradually blocked the antibacterial activity of curcumin (125 µg/mL); however, at a concentration of 125 µg/mL PGN, it did not completely block curcumin. Curcumin has a significant effect on the protein level of PBP2a. The TEM images of MRSA showed damage of the cell wall, disruption of the cytoplasmic contents, broken cell membrane and cell lysis after the treatment of curcumin. These data indicate a remarkable antibacterial effect of curcumin, with membrane permeability enhancers and ATPase inhibitors, and curcumin did not directly bind to PGN on the cell wall. Further, the antimicrobial action of curcumin involved in the PBP2a-mediated resistance mechanism was investigated.

The Antibacterial Assay of Tectorigenin with Detergents or ATPase Inhibitors against Methicillin-Resistant Staphylococcus aureus.

Tectorigenin (TTR) is an O-methylated isoflavone derived from the rhizome of Belamacanda chinensis (L.) DC. It is known to perform a wide spectrum of biological activities such as antioxidant, anti-inflammatory, anti-tumor. The aim of this study is to examine the mechanism of antibacterial activity of TTR against methicillin-resistant Staphylococcus aureus (MRSA). The anti-MRSA activity of TTR was analyzed in combination assays with detergent, ATPase inhibitors, and peptidoglycan (PGN) derived from S. aureus. Transmission electron microscopy (TEM) was used to monitor survival characteristics and changes in S. aureus morphology. The MIC values of TTR against all the tested strains were 125 µ g/mL. The OD(600) of each suspension treated with a combination of Triton X-100, DCCD, and NaN3 with TTR (1/10 × MIC) had been reduced from 68% to 80%, compared to the TTR alone. At a concentration of 125 µ g/mL, PGN blocked antibacterial activity of TTR. This study indicates that anti-MRSA action of TTR is closely related to cytoplasmic membrane permeability and ABC transporter, and PGN at 125 µ g/mL directly bind to and inhibit TTR at 62.5 µ g/mL. These results can be important indication in study on antimicrobial activity mechanism against multidrug resistant strains.

Tetrandrine suppresses pro-inflammatory mediators in PMA plus A23187-induced HMC-1 cells.

Tetrandrine (TET), a bis-benzylisoquinoline alkaloid from the root of Stephania tetrandra, is known to possess antitumor activity in various malignant neoplasms. However, the precise mechanism of TET-mediated immune modulation remains to be clarified. One of the possible mechanisms for its protective properties is by downregulation of the inflammatory responses. In the present study, the human mast cell line (HMC-1) was used to investigate this effect. TET significantly inhibited the induction of inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8 by phorbol 12-myristate 13-acetate (PMA) plus A23187. Moreover, TET attenuated expression of cyclooxygenase (COX)-2. In activated HMC-1 cells, the phosphorylation of extra-signal response kinase (ERK1/2) and c-jun N-terminal Kinase (JNK1/2), but not p38 mitogen-activated protein kinase, was decreased by treatment of the cells with TET. TET inhibited PMA plus A23187-induced nuclear factor (NF)-κB activation, IκB degradation and phosphorylation. Furthermore, TET suppressed the expression of TNF-α, IL-8, IL-6 and COX-2 through suppression of the ERK1/2, JNK1/2, IκBα degradation and phosphorylation, and NF-κB activation. These results indicated that TET exerted a regulatory effect on inflammatory reactions mediated by mast cells.

Anti-inflammatory effects of tectroside on UVB-induced HaCaT cells.

Ultraviolet B (UVB) irradiation causes skin damage and inflammation by inducing the secretion of various cytokines, which are immune regulators produced by cells. To prevent skin inflammation, keratinocytes that have been irreversibly damaged by UVB must be eliminated through apoptosis. Ixeris dentata (I. dentata) (family Asteraceae) is a perennial medicinal herb indigenous to Korea. It is used in Korea, China and Japan to treat indigestion, pneumonia, diabetes, hepatitis, contusions and tumors. Guaiane-type sesquiterpene lactones were isolated from the whole extract of I. dentata. This led to the isolation of the anti-inflammatory sesquiterpene lactone compound tectroside (TES), which was tested on a human keratinocyte cell line. To determine the anti-inflammatory effects of TES, we examined its influence on UVB-induced pro-inflammatory cytokine production in human keratinocytes (HaCaT cells) by observing these cells in the presence or absence of TES. In the present study, pro-inflammatory cytokine production was determined by performing enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction and western blot analysis to evaluate the activation of mitogen-activated protein kinases (MAPKs). TES inhibited UVB-induced production of the pro-inflammatory cytokines interleukin (IL)-6 and IL-8 in a dose-dependent manner. In addition, TES inhibited the expression of cyclooxygenase (COX)-2 and the phosphorylation of c-Jun NH2-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) MAPKs, suggesting that it inhibits the secretion of the pro-inflammatory cytokines IL-6 and IL-8 and COX-2 expression by blocking MAPK phosphorylation. These results suggest that TES can potentially protect against UVB-induced skin inflammation.

The anti-inflammatory effect of Cheongseoikki-tang ethanol extract on allergic reactions mediated by bone marrow-derived mast cells.

OBJECTIVE: Cheongseoikki-tang (CIT, Korean), also called Qingshu Yiqi decoction () and Seisho-ekki-to (Japanese), is well known as an effective traditional combination of herbs for treating cardiovascular diseases. This study was to research its effects on bone marrow-derived mast cell (BMMC)-mediated allergy and inflammation mechanisms. METHODS: In this study, the biological effect of Cheongseoikki-tang ethanol extract (CITE) was evaluated, focusing on its effects on the production of allergic mediators by phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187 (A23187)-stimulated BMMCs. These allergic mediators included interleukin-6 (IL-6), prostaglandin D2 (PGD2), leukotriene C4 (LTC4), and ß-hexosaminidase (ß-hex). RESULTS: Our data revealed that CITE inhibited the production of IL-6, PGD2, LTC4, and ß-hex induced by PMA plus A23187 (P<0.05). CONCLUSION: These findings indicate that CITE has the potential for use in the treatment of allergy.

Synergistic antibacterial effect of curcumin against methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) are spread among infected patients, with infection rates increasing at an alarming rate. Furthermore, increased resistance to antibiotics has resulted in serious challenges in the treatment of infectious diseases worldwide. Under the selection pressure of exposure to antibiotics, microorganisms evolve to survive against the new conditions imposed by therapy. Therefore, there exists a need to develop alternative natural or combination drug therapies. Curcumin (CCM), a natural polyphenolic flavonoid isolated from the rhizome of a plant, Curcuma longa Linné., has been found to possess many beneficial biological activities. The aim of this study was to investigate the synergistic effect of curcumin and antibiotics as well as to determine the antibacterial activity of CCM against specific MRSA strains. The antibacterial activity of CCM was assessed by the broth microdilution method (by calculating the minimal inhibitory concentration [MIC]), checkerboard dilution test, and time-kill assay. Antimicrobial activity of CCM was observed against all tested strains. The MICs of CCM against 10 strains of S. aureus ranged from 125 to 250 µg/ml. In the checkerboard test, CCM markedly reduced the MICs of the antibiotics oxacillin (OXI), ampicillin (AMP), ciprofloxacin (CIP), and norfloxacin (NOR) used against MRSA. The time-kill curves showed that a combined CCM and OXI treatment reduced the bacterial counts below the lowest detectable limit after 24h. This study suggested that CCM reduced the MICs of several antibiotics tested, notably of OXI, AMP, CIP, and NOR, and that CCM in combination with antibiotics could lead to the development of new combination of antibiotics against MRSA infection.