TRPM8 has a key role in experimental colitis-induced visceral hyperalgesia in mice

BACKGROUND

Transient receptor potential channel melastatin 8 (TRPM8) is activated by cold temperatures and cooling agents (menthol and icilin). Recent studies showed TRPM8 is expressed in visceral organs and peripheral sensory pathways. However, the role of TRPM8 in visceral hyperalgesia is poorly understood in pathological states such as inflammatory bowel disease. Hence, we investigated the distribution of TRPM8 and its involvement in visceral hyperalgesia in experimental colitis mice.

METHODS

TRPM8 immunoreactivity was detected using immunohistochemical staining with fluorescein-conjugated tyramide amplification. Visceral hyperalgesia was measured by the intracolonic administration of TRPM8 agonist, WS-12, in control and dextran sodium sulfate (DSS)-induced colitis mice.

KEY RESULTS

TRPM8 immunoreactivity in the distal colon was much higher than in the transverse and proximal colon under physiological conditions. TRPM8 immunoreactivity markedly increased in the distal colon mucosa of DSS-induced colitis mice compared with control mice. The number of TRPM8 nerve fibers in mucosa of DSS- or 2,4,6-trinitrobenzene sulfonic acid-induced colitis model mice drastically increased compared with control mice. TRPM8 immunoreactivities colocalized with the calcitonin gene-related peptide- and substance P-immunoreactive nerve fibers in the mucosa. Intracolonic administration of WS-12 induced behavioral visceral pain-like responses. The numbers of these responses in the colitis model mice were 3 times higher than in control mice, and were decreased by pretreatment with the TRPM8 channel blocker AMTB.

CONCLUSIONS & INFERENCES

Increased expression of TRPM8 may contribute to the visceral hyperalgesia of experimental colitis.

Echinolactones C and D: Two Illudalane Sesquiterpenoids Isolated from the Cultured Mycelia of the Fungus Echinodontium japonicum

Echinolactones C and D, two compounds with an illudalane sesquiterpenoid skeleton, were isolated from the cultured mycelia of the basidiomycetous fungus Echinodontium japonicum (Echinodontiaceae). The structures of echinolactones C and D were determined by 1D and 2D NMR spectroscopy. Their biological activities were determined using antimicrobial activity and lettuce seedling assays.

Three Sesquiterpenoids, Fascicularones E, F, and G Produced by the Fungus Hypholoma fasciculare

Three new sesquiterpenoids, fascicularones E, F, and G, were isolated from the liquid culture extract of the fungus Hypholoma fasciculare. Their structures were established based on spectroscopic data.

Antarones A and B, Two Polyketides from an Endophytic Penicillium antarcticum

Two new polyketides, antarones A and B, were isolated from the endophytic fungus Penicillium antarcticum. Their structures were determined by spectroscopic methods. Their general toxicity and cytotoxicity were evaluated, respectively, by brine shrimp lethality and cytotoxicity assay with human cancer cell lines. Neither antarones A nor B exhibited activity at the concentration of 100 μM.

Protoilludane-Type Sesquiterpenes, Echinocidins A and B, from a Mycelial Culture of Echinodontium tsugicola

Two novel protoilludane sesquiterpenoids, echinocidins A (3) and B, (4) have been isolated from an artificial liquid culture of the basidiomycetous fungus Echinodontium tsugicola and their structures clarified spectroscopically. Echinocidin A (3) accelerated primary root growth to 117% and echinocidin B to 180% of controls at a concentration of 100 ppm.

New Eremophilane-Type Sesquiterpenoids, Eremoxylarins A and B from Xylariaceous Endophytic Fungus YUA-026

Two new eremophilane sesquiterpenes, eremoxylarins A and B, were isolated from the xylariaceous endophytic fungus YUA-026. Their structures were determined by spectroscopic methods. Eremoxylarins A and B showed antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa.

Fusapyridons A and B, Novel Pyridone Alkaloids from an Endophytic Fungus, Fusarium sp. YG-45

Through our screening for new natural compounds, two 3,4,5-trisubstituted N-methyl-2-pyridone alkaloids, fusapyridons A (1) and B (2), along with the known compounds sambutoxin (3), Ndemethylsambutoxin (4), (-)-oxysporidinone (5), and the dimethyl ketal of oxysporidinone (6) were isolated from the fermentation extract of Fusarium sp. YG-45. Their structures were determined by spectroscopic analyses including NMR, MS, UV and IR. Compound 1 showed antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus.

A Polyketide Metabolite from an Endophytic Fusarium equiseti in a Medicinal Plant

A new polyketide, fusaequisin A (1), was isolated from rice cultures of Fusarium equiseti SF-3-17, an endophytic fungus previously discovered during screening of medicinal plants in Cameroon. The structure of 1 was determined using spectroscopic methods. Fusaequisin A (1) exhibited moderate antimicrobial activity against Staphylococcus aureus NBRC 13276 and Pseudomonas aeruginosa ATCC 15442 at a concentration of 200 μg per disk.

Two Drimane-type Sesquiterpenes, Strobilactones A and B, from the Liquid Culture of the Edible Mushroom Strobilurus ohshimae

Two novel drimane sesquiterpenoids, strobilactones A (3) and B (4), were isolated fromthe organic extract of a liquid culture of Strobilurus ohshimae. The structures of 3 and 4 were determined by spectroscopic methods. Compounds 3 and 4 exhibit cell growth inhibitory activities against cultured COLO 201 cells. Compound 4 also shows antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa.

A Cleistanthane Diterpene From a Marine-derived Fusarium Species Under Submerged Fermentation

A cleistanthane-type diterpene, compound 1, was isolated from the marine-derived Fusarium sp. FH-146. The structure of 1 was determined by 1D and 2D NMR spectroscopy. Compound 1 showed moderate antimicrobial, cytotoxic, and phytotoxic activities

Stimulatory Effect of Ferulic Acid on the Production of Extracellular Xylanolytic Enzymes byAspergillus kawachii

Production of extracellular beta-1,4-xylanase, alpha-L-arabinofuranosidase, feruloyl esterase, and acetyl xylan esterase from Aspergillus kawachii was higher in a culture supplemented with ferulic acid than in a counterpart. Culture supernatant grown on oat spelt xylan supplemented with ferulic acid exhibited an increase in ferulic acid-releasing activity from insoluble arabinoxylan relative as compared to that from the ferulic acid-free culture.

Molecular cloning and characterisation of the methionine sulphoxide reductase A (msrA) gene locus in Campylobacter lari organisms

The methionine sulphoxide reductase A (msrA) gene and its adjacent genetic loci from urease-negative (UN) Campylobacter lari RM2100 and urease-positive thermophilic Campylobacter (UPTC)CF89-12 strains appear to be composed of a msrA structure gene (507 base pairs [bp]) and another five-gene cluster (approximately 6300 bp) in the same strand and direction. A primer pair (F1/R4-msrA) for polymerase chain reaction (PCR) amplification was designed to generate a product of approximately 900 bp of the msrA gene, including its adjacent genetic loci for the thermophilic Campylobacter organisms and generate an amplicon with 16 C. lari isolates (n = 4 for UN C. lari; n = 12 for UPTC). Following direct nucleotide sequencing, sequence analysis and nucleotide sequence alignment analysis, the putative full-length msrA gene from the 16 C. lari isolates showed high nucleotide sequence similarities (91.8-100%) to each other and relatively low similarity (69.3-71.8%) to three reference C. jejuni and C. coli strains. In addition, the msrA gene was transcribed in both the UPTC CF89-12 and NCTC12893 cells using reverse transcription PCR. An immunoreactively positive signal was identified in the UPTC CF89-12 and NCTC12893 cells with anti-UPTC MsrA synthetic peptide antibodies.

Ethyl acetate fraction of Garcina epunctata induces apoptosis in human promyelocytic cells (HL-60) through the ROS generation and G0/G1 cell cycle arrest: a bioassay-guided approach

Number of deaths due to cancer diseases is increasing in the world. There is an urgent need to develop alternative therapeutic measures against the disease. Our study reports the cytotoxicity activity of Garcina epunctata (gutifferae) in human promyelocytic leukemia cells (HL-60) and prostate cancer cells (PC-3) was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Changes in mitochondrial membrane potential (MMP), reactive oxygen species (ROS) and morphological changes associated with apoptosis were examined by flow cytometry and Hoescht staining respectively. The results of in vitro antiproliferative screening of fractions and extract from G. epunctata indicated that three fractions inhibited the viability of PC-3 cells with IC₅₀ varied from 50 to 88 μ/ml while two fractions inhibited the proliferation of HL-60 cells with IC₅₀ range between 47.5 and 12 μg/ml. Among the entire fraction tested, Hex-EtOAc (75:25) showed cytotoxic effects on the two cell lines and EtOAc fraction was most active only HL-60 cells (12 μg/ml). Treatment of HL-60 cells with G. epunctata (20, 50, 100 μg/ml) for 24 h led to a significant dose-dependent increase in the percentage of cells in sub-G1 phase by analysis of the content of DNA in cells, and a number of apoptotic bodies containing nuclear fragments were observed in cells treated with 100 μg/ml. The EtOAc fraction of G. epunctata treatment significantly arrested HL-60 cells at the G0/G1 phase (p<0.05) and ROS was significantly elevated as well as the loss of membrane mitochondrial potential in a concentration dependant manner. The results demonstrated that the EtOAc fraction of G. epunctata inhibited the proliferation of HL-60 cells, leading to cell cycle arrest and programmed cell death, which was confirmed to occur through the mitochondrial pathway.

Cytotoxicity and modes of action of four naturally occuring benzophenones: 2,2',5,6'-tetrahydroxybenzophenone, guttiferone E, isogarcinol and isoxanthochymol

INTRODUCTION

The emergence of drug-resistant cancer cells drastically reduces the efficacy of many antineoplasic agents and, consequently, increases the frequency of therapeutic failure. Benzophenones are known to display many pharmacological properties including cytotoxic activities. The present study was aimed at investigating the cytotoxicity and the modes of action of four naturally occurring benzophenones 2,2',5,6'-tetrahydroxybenzophenone (1), isogarcinol (2), isoxanthochymol (3) and guttiferone E (4) on a panel of eleven cancer cell lines including various sensitive and drug-resistant phenotypes.

METHODS

The cytotoxicity of the compounds was determined using a resazurin reduction assay, whereas the caspase-Glo assay was used to detect the activation of caspases 3/7, caspase 8 and caspase 9 in cells treated with compounds 2-4. Flow cytometry was used for cell cycle analysis and detection of apoptotic cells, analysis of mitochondrial membrane potential (MMP) as well as measurement of reactive oxygen species (ROS).

RESULTS

The four tested benzophenones inhibited the proliferation of all tested cancer cell lines including sensitive and drug-resistant phenotypes. Collateral sensitivity of cancer cells to compounds 1-4 was generally better than to doxorubicin. Compound 2 showed the best activity with IC50 values below or around 1 μM against HCT116 colon carcinoma cells (p53+/+) (0.86 μM) and leukemia CCRF-CEM (1.38 μM) cell lines. Compounds 2-4 strongly induced apoptosis in CCRF-CEM cells via caspases 3/7, caspase 8 and caspase 9 activation and disruption of MMP.

CONCLUSIONS

The studied benzophenones are cytotoxic compounds that deserve more detailed exploration in the future, to develop novel anticancer drugs against sensitive and otherwise drug-resistant phenotypes.

Polyketide Metabolites from the Endophytic Fungus Microdiplodia sp. KS 75-1

Through our screening for new natural compounds, four new polyketide metabolites, 7,8-dihydonivefuranone A (1), 6(7)-dehydro-8-hydroxyterrefuranone (2), 8-hydroxyterrefuranone (3), and 6-hydroxyterrefuranone (4) were isolated from the fermentation extract of Microdiplodia sp. KS 75–1, together with the known compounds nivefuranones A (5) and B (6); their structures were determined by spectroscopic (NMR, UV and IR) and MS analysis.. Compounds 1, 2, 4 and 5 showed antimicrobial activity against Candida albicans and Staphylococcus aureus.