Rapid screening, isolation, and activity evaluation of potential xanthine oxidase inhibitors in Polyporus umbellatus and mechanism of action in the treatment of gout.

INTRODUCTION: Studies show that Polyporus umbellatus has some pharmacological effects in enhancing immunity and against gout. OBJECTIVES: We aimed to establish new techniques for extraction, biological activity screening, and preparation of xanthine oxidase inhibitors (XODIs) from P. umbellatus. METHODS: First, the extraction of P. umbellatus was investigated using the back propagation (BP) neural network genetic algorithm mathematical regression model, and the extraction variables were optimised to maximise P. umbellatus yield. Second, XODIs were rapidly screened using ultrafiltration, and the change of XOD activity was tested by enzymatic reaction kinetics experiment to reflect the inhibitory effect of active compounds on XOD. Meanwhile, the potential anti-gout effects of the obtained active substances were verified using molecular docking, molecular dynamics simulations, and network pharmacology analysis. Finally, with activity screening as guide, a high-speed countercurrent chromatography (HSCCC) method combined with consecutive injection and two-phase solvent system preparation using the UNIFAC mathematical model was successfully developed for separation and purification of XODIs, and the XODIs were identified using MS and NMR. RESULTS: The results verified that polyporusterone A, polyporusterone B, ergosta-4,6,8(14),22-tetraen-3-one, and ergosta-7,22-dien-3-one of P. umbellatus exhibited high biological affinity towards XOD. Their structures have been further identified by NMR, indicating that the method is effective and applicable for rapid screening and identification of XODIs. CONCLUSION: This study provides new ideas for the search for natural XODIs active ingredients, and the study provide valuable support for the further development of functional foods with potential therapeutic benefits.

Homogeneous Polyporus polysaccharide exerts anti-bladder cancer effects via autophagy induction.

CONTEXT: Polyporus polysaccharide (PPS), the leading bioactive ingredient extracted from Polyporus umbellatus (Pers.) Fr. (Polyporaceae), has been demonstrated to exert anti-bladder cancer and immunomodulatory functions in macrophages. OBJECTIVE: To explore the effects of homogeneous Polyporus polysaccharide (HPP) on the proliferation and autophagy of bladder cancer cells co-cultured with macrophages. MATERIALS AND METHODS: MB49 bladder cancer cells and RAW264.7 macrophages were co-cultured with or without HPP intervention (50, 100, or 200 µg/mL) for 24 h. The cell counting kit-8 (CCK-8) assay and 5-ethynyl-2″-deoxyuridine (EdU) staining evaluated MB49 cell proliferation. Monodansylcadaverine (MDC) staining and transmission electron microscopy (TEM) observed autophagosomes. Western blotting detected the expression levels of autophagy-related proteins and PI3K/Akt/mTOR pathway proteins. RESULTS: HPP inhibited the proliferation of MB49 cells co-cultured with RAW264.7 cells but not MB49 cells alone. HPP altered the expression of autophagy-related proteins and promoted the formation of autophagosomes in MB49 cells in the co-culture system. Autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CQ) not only antagonized HPP-induced autophagy but also attenuated the inhibitory effects of HPP on MB49 cell proliferation in the co-culture system. HPP or RAW264.7 alone was not sufficient to induce autophagy in MB49 cells. In addition, HPP suppressed the protein expression of the PI3K/Akt/mTOR pathway in MB49 cells in the co-culture system. DISCUSSION AND CONCLUSIONS: HPP induced bladder cancer cell autophagy by regulating macrophages in the co-culture system, resulting in the inhibition of cancer cell proliferation. The PI3K/Akt/mTOR pathway was involved in HPP-induced autophagy in the co-culture system.

Regiospecific 7-hydroxylation of ten-carbon monoterpenes by detoxifying CYP5035S7 monooxygenase of the white-rot fungus Polyporus arcularius.

In a previous study, we identified CYP5035S7 of the white-rot fungus Polyporus arcularius with a broad activity towards monoterpenes such as p-cymene. Therefore, in this study we aimed at further exploring the substrate scope of detoxifying CYP5035S7 towards terpenes and semi-preparatively isolating some of the products via whole-cell biotransformation, in order to obtain information about the enzyme's reactivity. We noticed a clear preference for the monoterpene skeleton and elucidated a distinct regioselectivity pattern based on key structural and electronic features of its substrates. This study illustrates how minimal characterisation effort may already suffice to provide vital information on enzymatic reactivity by the comparison of structural derivatives.

Evolution and enrichment of CYP5035 in Polyporales: functionality of an understudied P450 family.

Bioprospecting for innovative basidiomycete cytochrome P450 enzymes (P450s) is highly desirable due to the fungi's enormous enzymatic repertoire and outstanding ability to degrade lignin and detoxify various xenobiotics. While fungal metagenomics is progressing rapidly, the biocatalytic potential of the majority of these annotated P450 sequences usually remains concealed, although functional profiling identified several P450 families with versatile substrate scopes towards various natural products. Functional knowledge about the CYP5035 family, for example, is largely insufficient. In this study, the families of the putative P450 sequences of the four white-rot fungi Polyporus arcularius, Polyporus brumalis, Polyporus squamosus and Lentinus tigrinus were assigned, and the CYPomes revealed an unusual enrichment of CYP5035, CYP5136 and CYP5150. By computational analysis of the phylogeny of the former two P450 families, the evolution of their enrichment could be traced back to the Ganoderma macrofungus, indicating their evolutionary benefit. In order to address the knowledge gap on CYP5035 functionality, a representative subgroup of this P450 family of P. arcularius was expressed and screened against a test set of substrates. Thereby, the multifunctional enzyme CYP5035S7 converting several plant natural product classes was discovered. Aligning CYP5035S7 to 102,000 putative P450 sequences of 36 fungal species from Joint Genome Institute-provided genomes located hundreds of further CYP5035 family members, which subfamilies were classified if possible. Exemplified by these specific enzyme analyses, this study gives valuable hints for future bioprospecting of such xenobiotic-detoxifying P450s and for the identification of their biocatalytic potential. KEY POINTS: • The P450 families CYP5035 and CYP5136 are unusually enriched in P. arcularius. • Functional screening shows CYP5035 assisting in the fungal detoxification mechanism. • Some Polyporales encompass an unusually large repertoire of detoxification P450s.

Quantitative Analysis of Polysaccharide Composition in Polyporus umbellatus by HPLC-ESI-TOF-MS.

Polyporus umbellatus is a well-known and important medicinal fungus in Asia. Its polysaccharides possess interesting bioactivities such as antitumor, antioxidant, hepatoprotective and immunomodulatory effects. A qualitative and quantitative method has been established for the analysis of 12 monosaccharides comprising polysaccharides of Polyporus umbellatus based on high-performance liquid chromatography coupled with electrospray ionization-ion trap-time of flight-mass spectrometry. The hydrolysis conditions of the polysaccharides were optimized by orthogonal design. The results of optimized hydrolysis were as follows: neutral sugars and uronic acids 4 mol/L trifluoroacetic acid (TFA), 6 h, 120 °C; and amino sugars 3 mol/L TFA, 3 h, 100 °C. The resulting monosaccharides derivatized with 1-phenyl-3-methyl-5-pyrazolone have been well separated and analyzed by the established method. Identification of the monosaccharides was carried out by analyzing the mass spectral behaviors and chromatography characteristics of 1-phenyl-3-methyl-5-pyrazolone labeled monosaccharides. The results showed that polysaccharides in Polyporus umbellatus were composed of mannose, glucosamine, rhamnose, ribose, lyxose, erythrose, glucuronic acid, galacturonic acid, glucose, galactose, xylose, and fucose. Quantitative recoveries of these monosaccharides in the samples were in the range of 96.10-103.70%. This method is simple, accurate, and sensitive for the identification and quantification of monosaccharides, and can be applied to the quality control of Polyporusumbellatus as a natural medicine.

Green seaweeds (Ulva fasciata sp.) as nitrogen source for fungal cellulase production.

In developing countries, local enzyme production can help decrease the dependency of imported enzymes for bioconversion of e.g. cellulosic feedstocks, but the use of conventional nitrogen sources contributes significantly to such enzyme production cost. Use of local resources is therefore important to consider. Green seaweeds are marine macroalgae that are rich in nitrogen, but not exploited for their nitrogen content. Cellulase production was accomplished by using cocoa pod husk (CPH) and green seaweed (GS) (Ulva fasciata sp.) as growth substrates for Polyporus ciliatus CBS 366.74 in submerged cultivation. The nitrogen concentration of GS was comparable to that of CPH with 0.6% w/v peptone at 4% w/v substrate concentration. A decline of cellulase activity in peptone supplemented GS growth media indicated nitrogen sufficiency of GS to serve as a potential nitrogen source for the fungal growth and cellulase production. Comparison of enzyme production on CPH growth media supplemented with either GS or peptone based on equivalent carbon to nitrogen ratios was done for two Polyporus strains namely; P. ciliatus CBS 366.74 and P. brumalis CBS 470.77. Peptone could be substituted by up to 0.6% w/v with GS at inclusion levels of 50-100% of substrate concentration to attain satisfactory cellulase productivity. However, the cellulase productivity response varied among the two Polyporus species. This study demonstrated that green seaweeds may be used as alternative nitrogen sources for fungal cellulase production.

[A landscape of transcriptome analysis of three sclerotia growth stages in Polyporus umbellatus].

Polyporus umbellatus,a traditional Chinese precious medicine as long been used for eliminating dampness,diuresis and have effect on cancer,getting more and more popularly in China recently. And the developmental metabolic process of the medicinal fungus,P. umbellatus,has been gotten more attention. This study is for the first time to explore the three sclerotial growth stages in P. umbellatus,named " white Polyporus"( initial phase), " grey Polyporus"( developmental phase) and " black Polyporus"( mature phase),by utilizing the de novo transcriptome assembly analysis technology. Finally,we obtained 88. 12 Gb sequence containing85 235 unigenes( ≥200 bp) assembled and 100% were annotated. We identified genes differentially expressed among the three stages of the sclerotia and screened out MFSgst,ERG4/ERG24,WD40,Rho A,CYP450,PKS,GSase and CHS1,which may contribute to the production of medicinal secondary metabolites and the defense mechanism against the environmental stress and biological invasion. We did the qRT-PCR trial to verify our results,which is in line with expectations. Our results are purposed to unearth the molecular mechanism of the accumulation of active constituents in different stages of Polyporus sclerotia which can be applied in the production and protection of Polyporus effectively.

[Molecular identification of Armillaria gallica by PCR-RFLP analysis].

Armillaria gallica is a symbiotic fungus in the cultivation process of Gastrodia elata and Polyporus.The rhizomorph of A. gallica invades the stalk of the G. elata or the Sclerotium of the Polyporus,and is digested and utilized by the latter,becoming their important source of nutrition. Different nature of A. gallica affects the growth of G. elata and Polyporus. The authors collected A. gallica from 13 commercially available regions and screened two A. gallica,A and B,at the genetic and metabolic levels,in order to distinguish between the two A. gallica market. We have established convenient and effective DNA molecular identification method.By comparing the sequence differences between the A. gallica type A and type B invertase genes,PCR-RFLP primers were designed based on differential fragment. Primer ZTM.F/ZTM.R can amplified A. gallica type A and B,producing a band of about 304 bp in length. The restriction endonuclease EcoR V could recognize the difference sequence of A and B types of A. gallica. The type B was digested to form two fragments,thereby specifically identifying the A. gallica as type B. The established methods of PCR-RFLP is an accurate identification method for A. gallica. Therefore,in the cultivation process of G. elata and Polyporus,suitable strains can be selected according to different needs of variety,growth stage and ecological environment,and the yield and quality can be improved according to local conditions.

[Study on polysaccharide content and monosaccharide composition of Polyporus umbellatus from different production areas].

In order to provide scientific basics for exploitation and sufficient application of Polyporus umbellatus resources and study the monosaccharide composition of P. umbellatus polysaccharides,the anthrone-sulfuric acid method was applied to compare polysaccharide content of P. umbellatus from 17 producing areas. The monosaccharides were derived by 1-phenyl-3-methyl-5-pyrazolone( PMP) and the derivatives were identified by UPLC-MS/MS and the content of each monosaccharide component was determined simultaneously. The results demonstrated that there was a certain difference in total polysaccharide content of P. umbellatus from different regions,and the content of total P. umbellatus polysaccharide from Shaanxi province and Sichuan province( 1. 15% and 1. 90%) was relatively higher than that of others areas. Polysaccharides from P. umbellatus was mainly composed of eight monosaccharides,including glucose,glucuronic acid,galactose,ribose,xylose,arabinose,mannose and fucose. The contents of glucose( 17. 65 mg·g-1) was higher than others. The ribose was the lowest( 0. 13 mg·g-1). In addition,fructose,rhamnose and galacturonic acid were also detected in some samples. Furthermore,the results of cluster analysis( CA) and principal component analysis( PCA) indicated that totally 17 batches of P. umbellatus polysaccharide could be classified into three clusters,samples collected from Wuchang in Heilongjiang province were clustered into one group separately. The study can provide a basis for rational utilization of P. umbellatus resources,and also implies the sequence of monosaccharide linking and pharmacological activity of P. umbellatus polysaccharides.

Influence of light on lignin-degrading activities of fungal genus Polyporus s. str.

Six strains belonging to five species of Polyporus (P. arcularius, P. arcularioides, P. tricholoma, P. cfr. tricholoma, and P. varius), collected from an Atlantic Forest area in Misiones (Argentina), where species usually grow exposed to high temperatures and humidity, were identified by morphological and molecular analyses. P. tricholoma (BAFC 4536) and P. arcularioides (BAFC 4534) were selected by their lignin-degrading enzyme production, their ability to produce primordial of basidiomes under submerged fermentation, and the decrease in lignin content caused in Poplar wood (up to 29% after 45 days). Among several variables evaluated with a Plackett-Burman design (glucose, copper, vanillic acid and manganese concentration, incubation period, and light incidence), the most important factor affecting laccase and Mn-peroxidase (MnP) production by both strains, was light incidence. Light induced fruit body development but diminished laccase and MnP production. Moreover, a modified isoenzymatic laccase pattern was observed, showing additional isoenzymes when fungi were cultivated under darkness and differences in optimal temperature. Although the studied strains did not produce high laccase and MnP titers (uppermost detected 4230 and 90 U L-1 , respectively), their laccases showed thermal stability and optimal temperature above 70 °C, representing an interesting source in the search of thermo-tolerant enzymes for biotechnological applications.

[Molecular cloning and prokaryotic expression of a type II ribosome inactivating protein from Polyporus umbellatus].

A type Ⅱ ribosome inactivating protein (RIP) gene was cloned from Polyporus umbellatus sclerotia by RT-PCR method. The full open reading frame cDNA sequence of this gene was 873 bp in length and encoded a 290-aa protein with a molecular weight of 32.33 kDa and an isoelectric point of 5.58. Multiple sequence alignment revealed that the deduced amino acids possessed conserved domains of RICIN superfamily protein. A neighbor joining phylogenetic analysis suggests that PuRIP was closely related to RIP in Marasmius oreades. Real time PCR results showed that this gene expressed in all tested tissues of P. umbellatus. Meanwhile, the expression of this gene was significantly up-regulated in the part infected by Armillaria mellea. This result suggested that this PuRIP might played important role with potential biotic stress tolerance of P. umbellatus. Otherwise, we successfully constructed the pET15b-PuRIP plasmid, produced and purified the His-PuRIP fusion protein, which would provide the basic material for polyclonal antibody preparation and gene function research.

[Correlative analysis advance of chemical constituents of Polyporus umbellatus and Armillaria mellea].

Medicinal Polyporus umbellatus is the dry sclerotia of P. umbellatus, with the effect of diuresis; Armillaria mellea is a parasitic fungus which can infect plants up to 300 genera, with sedative, anticonvulsant and some other biological activities. As the medicinal value of P. umbellatus and A. mellea is increasingly wide concerned, the market quantity demanded of them is gradually increased and the demand outstrips the supply. The symbiotic A. mellea and P. umbellatus are both the medicinal and edible fungi with diverse activities, including hypoglycemic action, improve immunity and antitumor and so on. The growth of the sclerotia forming from the mycelium of P. umbellatus is related to the infection of the symbiotic A. mellea and their secondary products. In this study, by comparing the chemical constituents of the mycelium and sclerotia of P. umbellatus and A. mellea, we found that they all produced steroids and nitrogen-containing heterocycles. The sclerotia of P. umbellatus and A. mellea also produced triterpenes secondary metabolites. In addition, the mycelium and infected sclerotia of P. umbellatus mainly produced different steroids, and the sclerotia produced some other special secondary metabolites, such as long-chain fatty acids, ceramides, phenol and so on. By analyzing above all kinds of differences, speculated that these may be caused by the infection of the symbiotic A. mellea which mainly produced sesquiterpenes, diterpenes and other secondary metabolites. The contents and types of compounds of P. umbellatus and A. mellea are closely related to their symbiosis and reproduction, therefore, many symbiosis mechanisms should be found by utilizing more molecular biology technology to elucidate this complex symbiotic infection and provide scientific basis for improving the yield and quality of P. umbellatus and A. mellea.

[Molecular cloning and characterization of two kind of heat-shock protein gene from Polyporus umbellatus].

With RT-PCR approaches, the full-length cDNA of two heat shock protein genes were cloned from total RNA of the Polyporus umbellatus sclerotium. The full open reading frame cDNA sequence of the Hsp90 was 2 091 bp, encoding 696 amino acid residues with a predicted molecular mass of 78.9 kDa. The full open reading frame cDNA sequence of the Hsp70 was 1 944 bp, encoding 647 amino acid residues with a predicted molecular mass of 70.5 kDa. The Hsp90 and Hsp70 protein contained the conservative structure domain, respectively. Phylogenetic analysis showed that Hsp90 and Hsp90 from Trametes versicolor were clustered into one group, Hsp70 and Hsp70 from Fistulina hepatica were clustered into one group. Real-time PCR analysis showed that, the expression of Hsp90 and Hsp70 in the infected part by Amillariella mellea was upregulated. The expression profiling of Hsp90 and Hsp70 showed same patterns underbiotic stress. The results indicate that these two genes may play an important role in response to Amillariella mellea infection.

Diversity Analysis of Polyporus umbellatus in China Using Inter-simple Sequence Repeat (ISSR) Markers.

Polyporus (P.) umbellatus, an endangered medicinal fungus in China, is distributed throughout most areas of the country. Thirty-seven natural P. umbellatus samples collected from 12 provinces in China were subjected to the inter-simple sequence repeat (ISSR) assay to investigate the genetic diversity within and among the 11 natural populations. Nine ISSR primers selected from 100 primers produced 88 discernible DNA bands, with 46 being polymorphic. The frequency of polymorphism varied from 19.57 to 93.48% with an average of 61.26% across all populations. At the population level, the within-population variance was much greater (92.04%) than the between-population variance (7.96%) as revealed by analysis of molecular variance. Eleven P. umbellatus populations were grouped into two major clusters, and the clustering pattern displayed four groups using the unweighted pair-group method with an arithmetic mean dendrogram. Principal coordinate analysis further indicated that the genetic diversity of P. umbellatus strains was unevenly distributed and displayed a clustered distribution pattern instead. Within these clusters, subgrouping (Henan and Hubei) and cluster II (Jilin and Heilongjiang) related to the geographic distribution were evident. The present study provides the first global overview of P. umbellatus diversity analysis in China, which may open up new opportunities in comparative genetic research on this medicinal fungus in other countries.

[Molecular cloning and characterization of four small GTPase genes from medicinal fungus Polyporus umbellatus].

Four small GTPase genes which may be relative to sclerotial development were firstly cloned from medicinal fungus Polyporus umbellatus using rapid amplification of cDNA end PCR (RACE) method. The results showed that full-length cDNA of PuRhoA was 698 bp contained 585 bp ORF, which was predicted to encode a 194 amino acid protein with a molecular weight of 21.75 kD with an isoelectric point (pI) of 6.44; the full length cDNA of PuRhoA2 was 837 bp in length and encoded a 194 amino acid protein with a molecular weight of 21.75 kD and an isoelectric point (pI) of 6.33; the full length cDNA of Puypt1 was 896 bp in length and encoded a 204-aa protein with a molecular weight of 22.556 kD and an isoelectric point (pI) of 5.75; the full length cDNA of PuRas was 803 bp in length and encoded a 212-aa protein with a molecular weight of 23.821 kD and an isoelectric point (pI) of 5.2. There are fani acyl transferase enzyme catalytic site and myrcene-transferase enzyme catalytic site in PuRhoA1 while the PuRhoA2 only possess myrcene-transferase enzyme catalytic site. Puypt1 contains the Rab1-Ypt1 conserved domain of small GTPase family and PuRas contains the fani acyl transferase enzyme catalytic site. According to the phylogenetic analysis all these four small GTPase clustered with basidiomycete group. Quantitative real-time PCR analysis revealed that Puypt1, PuRas and PuRhoA1 transcripts were significantly higher in the beginning of sclerotial formation than that in the mycelia, whereas the transcripts levels of PuRhoA2 gene were particularly lower in sclerotia than that in mycelia, suggesting that these four genes might be involved in P umbellatus selerotial development.

[Molecular cloning and characterization of two oxidative stress related genes from medicinal fungus Polyporus umbellatus].

OBJECTIVE: To clone the NADPH gene (PuNOX) and Glyoxal oxidase gene (PuGLOX) from a medicinal fungus Polyporus umbellatus, and to carry out the bioinformatic analysis. METHODS: We used the Rapid Amplification of cDNA ends (RACE) technique to obtain the full length cDNA of these two genes. We used a series of bioinformatic tools to characterize physiochemical properties of the two deduced protein. The analyses of multiple alignment and phylogenetic trees were performed using Bioeditor and MEGA 5.0 softwares. RESULTS: The entire cDNA of PuNOX and PuGLOX were 1674 bp, 1723 bp in length and encoded a 557-amino acid protein and 515-amino acid protein with a molecular weight of 63.845 kDa and 55.891 kDa and the isoelectric point of 5.58 and 4.82, respectively. PuNOX had high identities (74 to 80%) with NADPH peroxidase from other fungus. From the evolutionary tree, PuNOX was closely related to that of Pleurotus ostreatus. PuGLOX had high identities (> 50%) with Glyoxal oxidases from various fungus. Phylogenetic tree analysis suggested that PuGLOX was closely related to that of Phanerochaete chrysosporium. CONCLUSION: Molecular characterization of the two oxidative stress related genes will be useful for further functional determination of the genes involved in the sclerotium development of Polyporus umbellatus.

[Habitat suitability assessment of medicinal Polyporus umbellatusin China based on Maxent modeling].

Geographic distribution of Polyporus umbellatus was predicted by using distribution records. Based on 42 distribution records from 12 provinces and bioclimatic data (1950-2000), georaphic distribution of P. umbellatus was modeled using Maxent. The results showed thatthe Receiver Operating Characteristic (ROC) curve analysis method was used to assess the accuracy of MAXENT model and the area under ROC curve (AUC) value of MAXENT was 0. 960 which suggested that the result of assessment was dependable. The geographic distribution pattern of were divided into three distribution block based on distribution values of 0.5-0.8: small area of Heilongjiang, Jilin, Liaoning and Hebei province, the board area of Yunnan, Guizhou and Sichuan, the southeast area of Tibet and the most area of Shanxi and Shannxi, the southeast board area of Shannxi, Gansu and Ningxia. Jackknife Test showed that average precipitation in warm seasons had the greatest contribution to the distribution gain of P. umbellatus, followed by mean temperature of driest quarter and annual mean temperature. The object suggests the potential distribution areasof P. umbellatus which is useful for the habitat conservation and introduction of P. umbellatus.

Khz-cp (crude polysaccharide extract obtained from the fusion of Ganoderma lucidum and Polyporus umbellatus mycelia) induces apoptosis by increasing intracellular calcium levels and activating P38 and NADPH oxidase-dependent generation of reactive oxygen species in SNU-1 cells.

BACKGROUND: Khz-cp is a crude polysaccharide extract that is obtained after nuclear fusion in Ganoderma lucidum and Polyporus umbellatus mycelia (Khz). It inhibits the growth of cancer cells. METHODS: Khz-cp was extracted by solvent extraction. The anti-proliferative activity of Khz-cp was confirmed by using Annexin-V/PI-flow cytometry analysis. Intracellular calcium increase and measurement of intracellular reactive oxygen species (ROS) were performed by using flow cytometry and inverted microscope. SNU-1 cells were treated with p38, Bcl-2 and Nox family siRNA. siRNA transfected cells was employed to investigate the expression of apoptotic, growth and survival genes in SNU-1 cells. Western blot analysis was performed to confirm the expression of the genes. RESULTS: In the present study, Khz-cp induced apoptosis preferentially in transformed cells and had only minimal effects on non-transformed cells. Furthermore, Khz-cp was found to induce apoptosis by increasing the intracellular Ca2+ concentration ([Ca2+]i) and activating P38 to generate reactive oxygen species (ROS) via NADPH oxidase and the mitochondria. Khz-cp-induced apoptosis was caspase dependent and occurred via a mitochondrial pathway. ROS generation by NADPH oxidase was critical for Khz-cp-induced apoptosis, and although mitochondrial ROS production was also required, it appeared to occur secondary to ROS generation by NADPH oxidase. Activation of NADPH oxidase was shown by the translocation of the regulatory subunits p47phox and p67phox to the cell membrane and was necessary for ROS generation by Khz-cp. Khz-cp triggered a rapid and sustained increase in [Ca2+]i that activated P38. P38 was considered to play a key role in the activation of NADPH oxidase because inhibition of its expression or activity abrogated membrane translocation of the p47phox and p67phox subunits and ROS generation. CONCLUSIONS: In summary, these data indicate that Khz-cp preferentially induces apoptosis in cancer cells and that the signaling mechanisms involve an increase in [Ca2+]i, P38 activation, and ROS generation via NADPH oxidase and mitochondria.

Decolorization and degradation mechanism of Amaranth by Polyporus sp. S133.

Polyporus sp. S133 decolorized the Amaranth in 72 h (30 mg L(-1)) under static and shaking conditions. Liquid medium containing glucose has shown the highest decolorization of Amaranth by Polyporus sp. S133. When the effect of increasing inoculum concentration on decolorization of Amaranth was studied, maximum decolorization was observed with 15 % inoculum concentration. Significant increase in the enzyme production of laccase (102.2 U L(-1)) was observed over the period of Amaranth decolorization compared to lignin peroxidase and manganese peroxidase. Germination rate of Sorghum vulgare and Triticum aestivum was less with Amaranth treatment as compared to metabolites obtained after its decolorization. Based on the metabolites detected by GC-MS, it was proposed that Amaranth was bio-transformed into two intermediates, 1-hydroxy-2-naphthoic acid and 1,4-naphthaquinone. Overall findings suggested the ability of Polyporus sp. S133 for the decolorization of azo dye and ensured the ecofriendly degradation of Amaranth.

Molecular characterization of manganese peroxidases from white-rot fungus Polyporus brumalis.

The cDNAs of six manganese-dependent peroxidases (MnPs) were isolated from white-rot fungus Polyporus brumalis. The MnP proteins shared similar properties with each other in terms of size (approximately 360-365 amino acids) and primary structure, showing 62-96 % amino acid sequence identity. RT-PCR analysis indicated that these six genes were predominantly expressed in shallow stationary culture (SSC) in a liquid medium. Gene expression was induced by treatment with dibutyl phthalate (DBP) and wood chips. Expression of pbmnp4 was strongly induced by both treatments, whereas that of pbmnp5 was induced only by DBP, while pbmnp6 was induced by wood chips only. Then, we overexpressed pbmnp4 in P. brumalis under the control of the GPD promoter. Overexpression of pbmnp4 effectively increased MnP activity; the transformant that had the highest MnP activity also demonstrated the most effective decolorization of Remazol Brilliant Blue R dye. Identification of MnP cDNAs can contribute to the efficient production of lignin-degradation enzymes and may lead to utilization of basidiomycetous fungi for degradation of lignin and numerous recalcitrant xenobiotics.