Cytotoxic effects of new geranyl chalcone derivatives isolated from the leaves of Artocarpus communis in SW 872 human liposarcoma cells

Breadfruit (Artocarpus communis Moraceae) is cultivated in tropical and subtropical regions as a traditional starch crop and also has potential medicinal properties. The aim of this work was to study the in vitro anticancer activity of compounds isolated from the leaves of Artocarpus communis. Three new geranyl chalcone derivatives including isolespeol (1), 5'-geranyl-2',4',4-trihydroxychalcone (2), and 3,4,2',4'-tetrahydroxy-3'-geranyldihydrochalcone (3), together with two known compounds lespeol (4) and xanthoangelol (5), were isolated from the leaves of Artocarpus communis. The structures of 1- 5 were elucidated by spectroscopy and through comparison with data reported in the literature. The effects of geranyl chalcone derivatives (1- 5) on the viability of human cancer cells (including SW 872, HT-29, COLO 205, Hep3B, PLC5, Huh7, and HepG2 cells) were investigated. The results indicate that isolespeol (1) showed the highest inhibitory activity with an IC 50 value of 3.8 muM in SW 872 human liposarcoma cells. Treatment of SW 872 human liposarcoma cells with isolespeol (1) caused the loss of mitochondrial membrane potential (DeltaPsim). Western blotting revealed that isolespeol (1) stimulated increased protein expression of Fas, FasL, and p53. The expression ratios of pro- and antiapoptotic Bcl-2 family members were also changed by isolespeol (1) treatment to subsequently induce the activation of caspase-9 and caspase-3, which was followed by cleavage of poly (ADP-ribose) polymerase (PARP). These results demonstrate that isolespeol (1) induces apoptosis in SW 872 cells through Fas- and mitochondria-mediated pathways.     

15N2–DNA–stable isotope probing of diazotrophic methanotrophs in soil

Nucleic acid stable isotope probing (SIP) is a powerful tool that can identify and characterize the microorganisms that mediate specific soil processes and explore the flow of C and N through functional groups in the soil food web. While ¹³C–SIP has been used successfully in a range of applications, methodological constraints have limited the applicability of ¹⁵N-labelled compounds in nucleic acid SIP. However, ¹⁵N–DNA–SIP can now be achieved and this method when used with ¹⁵N₂ provides a powerful new tool for characterizing free-living diazotrophs in natural ecosystems. A diverse array of non-cultivated diazotrophs have been observed in soil and yet the characteristics of these organisms and their environmental significance remain almost completely unknown. ¹⁵N₂–DNA–SIP can identify those diazotrophs that are active in situ while providing access to gene sequences and genome fragments that can yield insights on their evolutionary history and functional capacities. Further insights on the ecology of free-living diazotrophs in soil can be provided by performing ¹⁵N₂–DNA–SIP on microcosms in which the response of the diazotrophic community is determined in relation to experimental manipulation. We describe the use of ¹⁵N₂–DNA–SIP to explore linkages between different C sources and N-fixation by specific diazotroph populations in soil. Methane addition to soil was observed to stimulate N-fixation and the organisms that were found to be responsible for this activity were Type II methanotrophs most closely related to the genus Methylocystis. This report provides insights on the use of nucleic acid SIP to identify and characterize microorganisms that mediate specific soil processes and represents the first time that a specific group of methanotrophs has been shown to mediate N-fixation while in the soil environment.     

Luteolin ameliorates experimental lung fibrosis both in vivo and in vitro: implications for therapy of lung fibrosis

Lonicera japonica (Caprifoliaceae) has been known as an anti-inflammatory herb in traditional Chinese medicine for thousands of years and is used constantly for upper respiratory tract infections. Luteolin, an active flavonoid compound isolated from Lonicera japonica, has a spectrum of biological activities, especially with antioxidative and anti-inflammatory properties. However, whether luteolin has a direct inhibitory effect on lung fibrosis has not been established. In this study, we examined the effects of luteolin on lung fibrosis both in vivo and in vitro. We found that oral administration of luteolin (10 mg/kg) efficiently suppressed the neutrophil infiltration as well as TNF-α and IL-6 elevation in the bronchoalveolar lavage fluid in bleomycin-instilled C57BL/6J mice. Luteolin also alleviated collagen deposition, TGF-β1 expression, and lung fibrosis upon bleomycin instillation. A similar tendency was observed in both early and delayed luteolin-treated groups. Next, our in vitro studies showed that luteolin inhibited TGF-β1-induced α-SMA, type I collagen, and vimentin expression in primary cultured mouse lung fibroblasts. Moreover, luteolin significantly blocked TGF-β1-mediated epithelial marker (E-cadherin) downregulation and mesenchymal cell markers (fibronectin and vimentin) upregulation, as well as retaining epithelial morphology in human alveolar epithelial-derived A549 cells. Additionally, luteolin could attenuate TGF-β1-induced Smad3 phosphorylation in both lung fibroblasts and A549 cells. These findings suggest that luteolin has a potent antifibrotic activity; this effect was mediated, at least in part, by inhibition of lung inflammation and suppression of myofibroblast differentiation as well as epithelial-to-mesenchymal transition.     

Study on the antiinflammatory activity of methanol extract from seagrass Zostera japonica

Methanolic extracts from the seagrass Zostera japonica were extracted successively using n-hexane (n-C(6)H(14)), dichloromethane (CH(2)Cl(2)), ethyl acetate (EtOAc), and water to give the n-C(6)H(14) (16.8%), CH(2)Cl(2) (40.6%), EtOAc (34.1%), and H(2)O (8.5%) soluble fractions, respectively. We have demonstrated that the hexane fraction has the highest capacity to inhibit proIL-1beta expression as compared to other fractions in lipopolysaccharides (LPS)-stimulated J774A.1 murine macrophages. Further analysis of the composition and antiinflammatory activity of the subfraction H5 from hexane fraction showed that it had the best antiinflammatory capacity and that it's major constituents were fatty acids, including palmitic acid methyl ester (21.5%), palmitic acid (24.02%), linoleic acid methyl ester (13.09%), oleic acid methyl ester (8.41%), and linoleic acid (7.93%), respectively. H5 inhibited LPS-induced TNFalpha, IL-1beta, and IL-6 in a dose-dependent manner, suggesting that H5 is bioactive in antiinflammation in vitro. This study is the first to report the antiinflammatory activity of extracts obtained from the seagrass Z. japonica.     

Frictional afterslip following the 2005 Nias-Simeulue earthquake, Sumatra

Continuously recording Global Positioning System stations near the 28 March 2005 rupture of the Sunda megathrust [moment magnitude (Mw) 8.7] show that the earthquake triggered aseismic frictional afterslip on the subduction megathrust, with a major fraction of this slip in the up-dip direction from the main rupture. Eleven months after the main shock, afterslip continues at rates several times the average interseismic rate, resulting in deformation equivalent to at least a M(w) 8.2 earthquake. In general, along-strike variations in frictional behavior appear to persist over multiple earthquake cycles. Aftershocks cluster along the boundary between the region of coseismic slip and the up-dip creeping zone. We observe that the cumulative number of aftershocks increases linearly with postseismic displacements; this finding suggests that the temporal evolution of aftershocks is governed by afterslip.     

Revealing the compositions of the intestinal microbiota of three Anguillid eel species using 16S rDNA sequencing

Anguilla japonica, A. marmorata and A. bicolor pacifica are important eel species for aquaculture in Taiwan. In the past, seldom studies focused on the intestinal microbiome of them or the probiotics used in their cultivation. Probiotics are microbes that can improve the health of organisms, and the microbes isolated from the intestines of organisms might be the potential probiotics. Therefore, the aim of this study was to collect the intestinal mucus samples of these three eel species for investigating the autochthonous microbiome using 16S rDNA sequencing. The diversity, abundance of the intestinal microbiome and compositions of all the libraries were identified. Moreover, the composition of intestinal microbiome of eel was suggested that it would be affected by the waters and the characteristics of different eel species. Furthermore, most of the identified predominant genera of the intestinal microbiome of these three eel species, such as Cetobacterium, Clostridium, Shewanella, Acinetobacter and Bacteroides, seemed to have great potential as the probiotics. In the future, more studies shall be conducted to promote the practical application of these candidate probiotics for improving the techniques of eel farming.     

Molecular characterization,comparison of screening methods,and evaluation of cross‐pathogenicity of black rot (Xanthomonas campestris pv. campestris) strains from cabbage,choy sum,leafy mustard and pak choi from Taiwan

Choy sum (Brassica rapa var. parachinensis), leafy mustard (Brassica juncea) and pak choi (B. rapa var. chinensis) are highly nutritious components of diets in Taiwan and other Asian countries, and bacterial black rot caused by Xanthomonas campestris pv. campestris (Xcc) is a major biotic constraint in these crops. As very little was known about the Xcc strains from these crops in these regions, including their cross‐pathogenicity and aggressiveness on different hosts, Xcc strains were obtained from cabbage (Brassica oleracea var. capitata), choy sum, leafy mustard and pak choi crops in Taiwan. Two previously published PCR‐based assays reliably distinguished the Xcc strains from other Xanthomonas species and subspecies. Phylogenetic analysis based on repetitive sequence‐based PCR assays placed the Xcc strains in a clade distinct from other Xanthomonas species, and also showed host specificity. Although all of the Xcc strains from the different host species were pathogenic on all five Brassica test species in both a detached leaf assay and an intact plant assay, in the intact plant assay they showed differences in virulence or aggression on the different test hosts. The Xcc strains from leafy mustard and pak choi were consistently highly aggressive on all the test host genotypes, but the strains from choy sum and cabbage were less aggressive on leafy mustard and choy sum. The intact plant assay proved more discriminating and reliable than the detached leaf assay for comparing the aggressiveness of Xcc strains on different host genotypes, and so, with the new Xcc strains isolated in this study, will be useful for screening leafy brassica germplasm accessions for resistance to black rot.     

Apoptosis induction in BEFV-infected Vero and MDBK cells through Src-dependent JNK activation regulates caspase-3 and mitochondria pathways

Our previous report demonstrated that bovine ephemeral fever virus (BEFV)-infected cultured cells could induce caspase-dependent apoptosis. This study aims to further elucidate how BEFV activates the caspase cascade in bovine cells. BEFV replicated and induced apoptosis in Vero and Madin-Darby bovine kidney (MDBK) cells, and a kinetic study showed a higher efficiency of replication and a greater apoptosis induction ability of BEFV in Vero cells. Src and c-Jun N-terminal kinase (JNK) inhibitor, but not extracellular signal-regulated kinase (ERK) or p38 inhibitor, alleviated BEFV-mediated cytopathic effect and apoptosis. In BEFV-infected Vero and MDBK cells, BEFV directly induced Src tyrosine-418 phosphorylation and JNK phosphorylation and kinase activity, which was inhibited specifically by SU6656 and SP600125, respectively. The caspase cascade and its downstream effectors, Poly (ADP-ribose) polymerase (PARP) and DFF45, were also activated simultaneously upon BEFV infection. In addition, cytochrome c, but not Smac/DIABLO, was released gradually from mitochondria after BEFV infection. SU6656 suppressed Src, JNK, and caspase-3 and -9 activation, as well as PARP and DFF45 cleavage; SP600125 reduced JNK and caspase-3 and -9 activation, as well as PARP and DFF45 cleavage. Taken together, these results strongly support the hypothesis that a Src-dependent JNK signaling pathway plays a key role in BEFV-induced apoptosis. The molecular mechanism identified in our study may provide useful information for the treatment of BEFV.