Ascorbic acid reduces HMGB1 secretion in lipopolysaccharide-activated RAW 264.7 cells and improves survival rate in septic mice by activation of Nrf2/HO-1 signals.

High mobility group box 1 (HMGB1) is now recognized as a late mediator of sepsis. We tested hypothesis that ascorbic acid (AscA) induces heme oxygenase (HO)-1 which inhibits HMGB1 release in lipopolysaccharide (LPS)-stimulated cells and increases survival of septic mice. AscA increased HO-1 protein expression in a concentration- and time-dependent manner via Nrf2 activation in RAW 264.7 cells. HO-1 induction by AscA was significantly reduced by Nrf2 siRNA-transfected cells. Mutation of cysteine to serine of keap-1 proteins (C151S, C273S, and C288S) lost the ability of HO-1 induction by AscA, due to failure of translocation of Nrf-2 to nucleus. The PI3 kinase inhibitor, LY294002, inhibited HO-1 induction by AscA. Oxyhemoglobin (HbO2), LY294002, and ZnPPIX (HO-1 enzyme inhibitor) reversed effect of AscA on HMGB1 release. Most importantly, administration of AscA (200mg/kg, i.p.) significantly increased survival in LPS-induced endotoxemic mice. In cecal ligation and puncture (CLP)-induced septic mice, AscA reduced hepatic injury and serum HMGB1 and plasminogen activator inhibitor (PAI)-1 in a ZnPPIX-sensitive manner. In addition, AscA failed to increase survival in Nrf2 knockout mice by LPS. Thus, we concluded that high dose of AscA may be useful in the treatment of sepsis, at least, by activation of Nrf2/HO-1 signals.

Inhibitory effects of seaweed extracts on the growth of the vaginal bacterium Gardnerella vaginalis.

Of 44 species of seaweed screened for potential anti-Gardnerella vaginalis activity, 27 (61.4%) showed antimicrobial activity by the agar disk-diffusion method. Among them, the strongest activities against the pathogen were exhibited by Chlorophyta, with Ulva pertusa producing an 11.3-mm zone of inhibition at 5 mg disk⁻¹. The MIC values of U. pertusa extracts against both G. vaginalis KCTC 5096 and KCTC 5097, the main cause of vaginosis, were 312 µg ml⁻¹, while the MIC values against both Candida albicans KCTC 7270 and KCTC 7965, the main cause of candidiasis, were 2.5 mg ml⁻¹. Against Lactobacillus gasseri KCTC 3173 and Lactobacillus jensenii KCTC 5194, members of the normal vaginal microflora, no inhibitory effect was seen even at 10 mg ml⁻¹. To identify the primary active compounds, a U. pertusa powder was successively fractionated according to polarity, and the main active agents against G. vaginalis KCTC 5096 were determined to be nitrogenous compounds (156 µg ml⁻¹ of the MIC value). According to these results, it was suggested that extracts of the seaweed U. pertusa are valuable for the development of natural therapeutic agents for treating women with bacterial vaginosis.

Antibacterial effect of grapefruit seed extract (GSE) on Makgeolli-brewing microorganisms and its application in the preservation of fresh Makgeolli.

UNLABELLED: To develop a new preservation method, the antimicrobial activity of grapefruit seed extract (GSE) against Makgeolli-brewing microorganisms and food-borne pathogens was assessed, and a general analysis and sensory evaluation of fresh Makgeolli with added GSE was made. The minimum inhibitory concentration (MIC) values of GSE against 10 strains of Makgeolli-brewing microorganism were 0.0122 to 1.5625 µL/mL. The MIC values against 6 strains of food-borne pathogens were 0.0061 to 0.7813 µL/mL. On addition of 0.1% (v/v) and 0.2% GSE in bottled fresh Makgeolli, no significant difference in the pH, or the contents of total acids, ethanol, or methanol in the Makgeolli, were observed compared with control Makgeolli (with no GSE), during the preservation period (8 weeks) at 10 °C. In the Makgeolli with 0.1% and 0.2% GSE, the total bacterial counts decreased significantly by 4.9% (P < 0.01) and 11.2% (P < 0.001), respectively, versus the control. The decreases in yeast count were significantly lessened by 15.33% and 15.24% (both P < 0.001), respectively, after 8 weeks of storage, compared with the control. In the sensory evaluation of Makgeolli with 0.1% and 0.2% GSE, the refreshment and overall acceptability received significantly better scores than the control (P < 0.01), with no change in sweetness, bitterness, sourness, turbidity, color, or odor. These results suggest that GSE controls the growth of Makgeolli-brewing microorganisms and extends the shelf life (ca. 2 wk), without decreasing overall acceptance. PRACTICAL APPLICATION: A new preservation method for fresh Makgeolli by adding grapefruit seed extract (GSE) was developed. As fresh Makgeolli contains live microorganisms, the preservation period is 1 wk, which is relatively short. GSE controls the growth of Makgeolli-brewing and Makgeolli-spoiling microorganisms. 0.1% to 0.2% GSE is optimum for prolonging the shelf life (2 wk) of bottled fresh Makgeolli, and has no adverse effect on overall acceptability. We demonstrated that GSE is an effective natural additive that prolongs the shelf life of fresh Makgeolli with no significant loss in quality.

Seasonal variation of antibacterial activities in the green alga Ulva pertusa Kjellman.

The present study was performed to screen out the extracts of algae and assess the seasonal variation in antimicrobial activity of Ulva pertusa against Gardnerella vaginalis. Seasonal variation in antibacterial activity was observed, with the extracts showing no activity during summer and autumn, and showing antibacterial activity from early winter (December) to middle spring (April). The maximum value of antimicrobial activity (6.5 mm inhibition zone at 5 mg disk(-1)) of U. pertusa against G. vaginalis was observed in April. Otherwise, for both chlorophyll a and b, the highest content (2.87 mg g(-1) and 1.37 mg g(-1)) was observed in March 2009. These results may reflect variation in cellular chemical compositions such as secondary metabolite(s) rather than chlorophyll and biological activities according to season.

Inhibition of oral pathogens and collagenase activity by seaweed extracts.

Fifty-seven species of common seaweed from the Coast of Korea were screened for antimicrobial (i.e. inhibition of Prevotella intermedia and Porphyromonas gingivalis growth) activity. As a source of bioactive compounds, seaweeds can produce many secondary metabolites with a variety of activities. Using the agar diffusion method, only 17 species (29.8%) showed inhibitory activity. Of these, methanol extracts of Enteromorpha linza, Sargassum sagamianum, and Ulva pertusa showed strong inhibitory effects against both P. intermedia and P. gingivalis. The MIC values of E. linza, S. sagamianum, and U. pertusa extracts against P. intermedia were 625, 78 and 625 microg ml(-1) and those against P. gingivalis were 312, 156 and 625 microg ml(-1), respectively. When these three species' extracts were separated into five fractions according to their polarity, the main active agents were determined to be phenolic compounds. We then compared the antimicrobial activities of these phenolic compounds against various periodontal pathogens using a MIC test. Phenolic compound containing extracts at concentrations of 10 to 100 microg ml(-1) showed a moderate to significant inhibitory effect on collagenase 1,2 and 3 activity.

Anti-inflammatory action of methanol extract of Carthamus tinctorius involves in heme oxygenase-1 induction.

ETHNOPHARMACOLOGICAL RELEVANCE: The methanol extracts of Carthamus tinctorius (MEC) have long been used in traditional medicine as anti-inflammatory agent, however, the molecular mechanism by which MEC shows anti-inflammatory action is not investigated. AIM OF THE STUDY: Induction of heme oxygenase-1 (HO-1) by many medicinal herbs has been reported excellent anti-inflammatory action. Thus, the aim of the study is to explore whether anti-inflammatory action of MEC is related with HO-1 induction in RAW 264.7 cells. MATERIALS AND METHODS: The present study was designed to investigate as to MEC induces HO-1 expression so that it reduces inflammation by suppression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in cells activated with lipopolysaccharide (LPS). RESULTS: Expression of HO-1 protein by MEC in macrophages was increased in a concentration- and time-dependent manner. Treatment with MEC significantly inhibited upregulation of both iNOS and COX-2 in LPS-activated macrophages and consequently reduced production of NO and PGE(2), respectively. The reduced expression of iNOS and COX-2 by MEC was reversed by siHO-1 RNA transfection. In addition, NF-E2-related factor (Nrf2) was translocated from cytosol to nucleus by MEC. The binding of NF-κB as well as NF-κB luciferase activity was also significantly diminished by MEC. Finally, tumor necrosis factor (TNF)-α-mediated VCAM-1 expression in endothelial cell was significantly inhibited by MEC. CONCLUSIONS: The present results show that MEC induces HO-1 expression via Nrf2 translocation and inhibits NF-κB activity, which may be responsible for anti-inflammatory action. Therefore, we propose that anti-inflammatory action of MEC involves at least HO-1 induction.

Isoimperatorin, cimiside E and 23-O-acetylshengmanol-3-xyloside from Cimicifugae rhizome inhibit TNF-α-induced VCAM-1 expression in human endothelial cells: involvement of PPAR-γ upregulation and PI3K, ERK1/2, and PKC signal pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: The methanol extract of Cimicifugae Rhizome has been traditionally used in various disorders including inflammation. AIM OF THE STUDY: The aim of the study is to explore whether anti-inflammatory action of 3 active compounds, two triterpenoid glycosides (cimiside E, 23-O-actylshengmanol-3-xyloside) and one furanocoumarin (isoimperatorin), isolated from Cimicifugae Rhizome is related with peroxisome proliferator-activated receptor-γ (PPAR-γ) expression in human umbilical endothelial cell line, EA.hy926 cells. MATERIALS AND METHODS: Cell viability and production of reactive oxygen species were performed. In addition, adhesion of monocyte into endothelial cells and western blot for expression of adhesion molecules and signal proteins were investigated in tumor necrosis factor-α (TNF-α)-activated cells. RESULTS: Pretreatment of test compounds significantly reduced reactive oxygen species (ROS) production and expression of vascular cell adhesion molecule-1 (VCAM-1), but not intercellular cell adhesion molecule-1 (ICAM-1). Three compounds all dose-dependently increased not only PPAR-γ expression in EA.hy926 cells but inhibited TNF-α-induced phosphorylation of Akt, extracellular-signal-regulated kinase (ERK) and protein kinase C (PKC) with different specificity. Finally, they prevented TNF-α-induced adhesion of U937 monocytic cells to EA.hy926 cells. CONCLUSIONS: The present results show that cimiside E, 23-O-actylshengmanol-3-xyloside, isoimperatorin isolated from Cimicifugae Rhizome selectively inhibits TNF-α-induced expression of VCAM-1 at least by upregulation of PPAR-γ, and signals for ERK1/2, PI3K, and PKC are involved in this effect.

Palmatine from Coptidis rhizoma reduces ischemia-reperfusion-mediated acute myocardial injury in the rat.

The aim of the present study was to evaluate the protective effect of palmatine, one of active ingredients of Coptidis rhizoma, against myocardial ischemia-reperfusion (I/R) injury is due to its antioxidant and anti-inflammatory action. Adult male rats were subjected to 30 min of ischemia and 6 or 24h of reperfusion. Rats were randomized to receive vehicle or palmatine 1h before reperfusion. Infarct size, myocardial function, and the antioxidant enzyme activity, such as malonaldehyde (MDA), lactate dehydrogenase (LDH), creatine phosphokinase (CK), superoxide dismutase (SOD) and catalase (CAT) were measured. Palmatine significantly improved I/R-induced myocardial dysfunction by increasing the values of the first derivative (+/-dp/dt) of left ventricular pressure and decreased infarct size by 50% (P<0.01 versus vehicle). As expected, palmatine markedly inhibited the increase of LDH, CK, and MDA contents in I/R rat serum, and it also significantly inhibited the decline of the activity of SOD and CAT in I/R cardiac tissues. In addition, COX-2 and iNOS expression in I/R myocardium was significantly reduced. Interestingly, palmatine increased heme oxygenase (HO)-1 induction in human aortic endothelial cells. We concluded that palmatine protects hearts from I/R injury in rats possibly by reducing oxidative stress and modulating inflammatory mediators.

Anti-apoptotic effect of magnolol in myocardial ischemia and reperfusion injury requires extracellular signal-regulated kinase1/2 pathways in rat in vivo.

Magnolol, an active component extracted from Magnolia officinalis, has been reported to have protective effect on ischemia and reperfusion (I/R)-induced injury in experimental animals. The aim of the present investigation was to further evaluate the mechanism(s) by which magnolol reduces I/R-induced myocardial injury in rats in vivo. Under anesthesia, left anterior descending (LAD) coronary artery was occluded for 30 min followed by reperfusion for 24 h (for infarct size and cardiac function analysis). In some experiments, reperfusion was limited to 1 h or 6 h for analysis of biochemical and molecular events. Magnolol and DMSO solution (vehicle) were injected intra-peritoneally 1 h prior to I/R insult. The infarct size was measured by TTC technique and heart function was monitored by Millar Catheter. Apoptosis related events such as p-ERK, p-Bad, Bcl-xl and cytochrome c expression were evaluated by Western blot analysis and myocardial caspase-3 activity was also measured. Magnolol (10 mg/kg) reduced infarct size by 50% (P < 0.01 versus vehicle), and also improved I/R-induced myocardial dysfunction. Left ventricular systolic pressure and positive and negative maximal values of the first derivative of left ventricular pressure (dP/dt) were significantly improved in magnolol-treated rats. Magnolol increased the expression of phosphor ERK and Bad which resulted in inhibition of myocardial apoptosis as evidenced by TUNEL analysis and DNA laddering experiments. Application of PD 98059, a selective MEK1/2 inhibitor, strongly antagonized the effect of magnolol. Taken together, we concluded that magnolol inhibits apoptosis through enhancing the activation of ERK1/2 and modulation of the Bcl-xl proteins which brings about reduction of infarct size and improvement of cardiac function in I/R-induced injury.