Effects of intravenous cariporide on release of norepinephrine and myoglobin during myocardial ischemia/reperfusion in rabbits

Aims

To examine the effects of cariporide, a Na⁺/H⁺ exchanger-1 inhibitor, on cardiac norepinephrine (NE) and myoglobin release during myocardial ischemia/reperfusion by applying a microdialysis technique to the rabbit heart.

Main methods

In anesthetized rabbits, two dialysis probes were implanted into the left ventricular myocardium and were perfused with Ringer's solution. Cariporide (0.3 mg/kg) was injected intravenously, followed by occlusion of the left circumflex coronary artery. During 30-min coronary occlusion followed by 30-min reperfusion, four consecutive 15-min dialysate samples (two during ischemia and two during reperfusion) were collected in vehicle and cariporide-treated groups. Dialysate myoglobin and NE concentrations were measured by immunochemistry and high-performance liquid chromatography, respectively.

Key findings

Dialysate myoglobin and NE concentrations increased significantly during myocardial ischemia/reperfusion in both vehicle and cariporide-treated groups (P < 0.01 vs. baseline). In cariporide-treated group, dialysate myoglobin concentrations were significantly lower than those in vehicle group throughout ischemia/reperfusion (P < 0.01 at 0–15 min of ischemia, P < 0.05 at 15–30 min of ischemia, P < 0.01 at 0–15 min of reperfusion, and P < 0.01 at 15–30 min of reperfusion). However, dialysate NE concentrations in cariporide-treated group were lower than those in vehicle group only during ischemia (P < 0.01 at 0–15 min of ischemia, and P < 0.05 at 15–30 min of ischemia).

Significance

When administered before ischemia, cariporide reduces myoglobin release during ischemia/reperfusion and decreases NE release during ischemia.     

Marine Hydroquinone Zonarol Prevents Inflammation and Apoptosis in Dextran Sulfate Sodium-Induced Mice Ulcerative Colitis

Background and Aim

We previously identified an anti-inflammatory compound, zonarol, a hydroquinone isolated from the brown algae Dictyopteris undulata as a marine natural product. To ascertain the in vivo functions of zonarol, we examined the pharmacological effects of zonarol administration on dextran sulfate sodium (DSS)-induced inflammation in a mouse model of ulcerative colitis (UC). Our goal is to establish a safe and effective cure for inflammatory bowel disease (IBD) using zonarol.

Methods and Results

We subjected Slc:ICR mice to the administration of 2% DSS in drinking water for 14 days. At the same time, 5-aminosalicylic acid (5-ASA) at a dose of 50 mg/kg (positive control) and zonarol at doses of 10 and 20 mg/kg, were given orally once a day. DSS-treated animals developed symptoms similar to those of human UC, such as severe bloody diarrhea, which were evaluated by the disease activity index (DAI). Treatment with 20 mg/kg of zonarol, as well as 5-ASA, significantly suppressed the DAI score, and also led to a reduced colonic ulcer length and/or mucosal inflammatory infiltration by various immune cells, especially macrophages. Zonarol treatment significantly reduced the expression of pro-inflammatory signaling molecules, and prevented the apoptosis of intestinal epithelial cells. Finally, zonarol protected against in vitro lipopolysaccharide (LPS)-induced activation in the RAW264.7 mouse macrophage cell line.

Conclusions

This is the first report that a marine bioproduct protects against experimental UC via the inhibition of both inflammation and apoptosis, very similar to the standard-of-care sulfasalazine, a well-known prodrug that releases 5-ASA. We believe that the oral administration of zonarol might offer a better treatment for human IBDs than 5-ASA, or may be useful as an alternative/additive therapeutic strategy against UC, without any evidence of side effects.     

Suppression of Microbial Metabolic Pathways Inhibits the Generation of the Human Body Odor Component Diacetyl by Staphylococcus spp

Diacetyl (2,3-butanedione) is a key contributor to unpleasant odors emanating from the axillae, feet, and head regions. To investigate the mechanism of diacetyl generation on human skin, resident skin bacteria were tested for the ability to produce diacetyl via metabolism of the main organic acids contained in human sweat. l-Lactate metabolism by Staphylococcus aureus and Staphylococcus epidermidis produced the highest amounts of diacetyl, as measured by high-performance liquid chromatography. Glycyrrhiza glabra root extract (GGR) and α-tocopheryl-l-ascorbate-2-O-phosphate diester potassium salt (EPC-K1), a phosphate diester of α-tocopherol and ascorbic acid, effectively inhibited diacetyl formation without bactericidal effects. Moreover, a metabolic flux analysis revealed that GGR and EPC-K1 suppressed diacetyl formation by inhibiting extracellular bacterial conversion of l-lactate to pyruvate or by altering intracellular metabolic flow into the citrate cycle, respectively, highlighting fundamentally distinct mechanisms by GGR and EPC-K1 to suppress diacetyl formation. These results provide new insight into diacetyl metabolism by human skin bacteria and identify a regulatory mechanism of diacetyl formation that can facilitate the development of effective deodorant agents.     

Isolation of Tannin-Degrading Lactobacilli from Humans and Fermented Foods

Lactobacilli with tannase activity were isolated from human feces and fermented foods. A PCR-based taxonomic assay revealed that the isolates belong to Lactobacillus plantarum, L. paraplantarum, and L. pentosus. Additional studies on a range of Lactobacillus species from established culture collections confirmed that this enzymatic activity is a phenotypic property common to these three species.     

Hydrolysis of newspaper polysaccharides under sulfate reducing and methane producing conditions

The initial decomposition rates of cellulose and hemicellulose were measured using toluene to specifically inhibit the microbial uptake of hydrolysis products during the degradation of newspaper under sulfate reducing and methane producing conditions. The amount of glucose and xylose accumulation in the first 2 weeks of incubation period was higher in the sulfate reducing condition compared to the methane producing condition. It was estimated that 28 and 6% of initially loaded cellulose in the sulfate reducing condition and the methane producing condition was hydrolyzed, respectively. Accordingly, the newspaper-cellulose hydrolysis rate constant was estimated to be 6.7 times higher in sulfate reducing condition than in methane producing condition. Based on the glucose accumulation patterns, when sulfate reducing bacteria (SRB) were inhibited by anthraquinone and molybdate (Na₂MoO₄), it may be suggested that SRB might have contributed to the hydrolysis of cellulose, while their effect on the hydrolysis of hemicellulose could not be elucidated.     

Cytoplasmic pH in the action of epidermal growth factor (EGF) in cultured porcine thyroid cells

We demonstrate measurement of cytoplasmic pH (pHi), using 2',7'-bis(2-carboxyethyl)-5 (and 6-) carboxyfluorescein (BCECF), and internalized fluorescent pHi indicator, in thyroid cells. Using cultured porcine thyroid cells, we studied the effects of epidermal growth factor (EGF) on pHi and [3H] thymidine incorporation; 10 nM EGF alkalinizes thyroid cells and stimulates thymidine incorporation. The results indicate that Na+/H+ exchange or cell alkalinization may function as a transmembrane signal transducer in the action of EGF in the thyroid cells.     

Toxicity of gentamicin in organ culture of fetal rat intestine.

The effect of gentamicin in the culture of fetal rat intestine was studied. Fetal rat intestine was cultured with gentamicin or kanamycin at the concentration between 4 to 200 micrograms/ml. Kanamycin did not have influence on lactase, maltase and ALP activities. On the other hand, gentamicin caused decrease of lactase and ALP activities at the concentration of 40 and 200 micrograms/ml compared with the activities at 4 micrograms/ml. Maltase activities did not decrease with gentamicin. Our data suggest that gentamicin could affect lactase and ALP activities and lower concentration should be used in the culture.     

Growth inhibition by danazol in a human endometrial cancer cell line with estrogen-independent progesterone receptors

Since we recently found that danazol, an isoxazol derivative of ethinyltestosterone, has a growth-inhibitory effect on human endometrial cancer cells in primary culture, the effects of danazol on a human endometrial cancer cell line (IK-90 cells), which contains estrogen-independent progesterone receptors (PR), were investigated in the present study. The addition of danazol (1 nM-1 microM) in culture medium caused a decrease in the growth of IK-90 cells in a dose-dependent manner. Competitive binding studies showed that danazol effectively binds to PR in IK-90 cells, and the binding affinity for PR was estimated to be 6.0% of that of R5020. The addition of 1 microM danazol in culture medium resulted in a rapid and significant increase in nuclear PR with a concomitant decrease in cytoplasmic PR in the cells. These findings suggest that danazol has a growth-inhibitory effect on human endometrial adenocarcinoma cells directly through PR system in the cells.     

Structural Alteration of Humic Acids by Pseudomonas spp. from Deep Terrestrial Subsurface Diatomite Formations in Northernmost Japan

Bacterial utilization of humic acids (HAs) was examined under aerobic conditions using Pseudomonas spp. from diatomite from a depth of 250 m below ground level in the Horonobe Underground Research Laboratory. HA decolorization and bacterial aggregation were observed during cultivation when an auxiliary carbon source was added. High-performance size-exclusion chromatography showed that high-molecular-weight HAs were produced. Fourier transform infrared spectroscopy indicated that carboxyl groups and polysaccharide-related substances in HAs were eliminated, while aliphatic structural units and amide groups were added to HAs. These results suggested that Pseudomonas spp. utilize and alter the molecular structure of HAs under aerobic conditions caused by the construction of underground facilities.