184 research outputs found

    Herbal Remedies for Combating Irradiation: a Green Antiirradiation Approach

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    Plants play important roles in human life not only as suppliers of oxygen but also as a fundamental resource to sustain the human race on this earthly plane. Plants also play a major role in our nutrition by converting energy from the sun during photosynthesis. In addition, plants have been used extensively in traditional medicine since time immemorial. Information in the biomedical literature has indicated that many natural herbs have been investigated for their efficacy against lethal irradiation. Pharmacological studies by various groups of investigators have shown that natural herbs possess significant radioprotective activity. In view of the immense medicinal importance of natural product based radioprotective agents, this review aims at compiling all currently available information on radioprotective agents from medicinal plants and herbs, especially the evaluation methods and mechanisms of action. In this review we particularly emphasize on ethnomedicinal uses, botany, phytochemistry, mechanisms of action and toxicology. We also describe modern techniques for evaluating herbal samples as radioprotective agents. The usage of herbal remedies for combating lethal irradiation is a green antiirradiation approach for the betterment of human beings without high cost, side effects and toxicity

    The genome of the Tiger Milk mushroom, Lignosus rhinocerotis, provides insights into the genetic basis of its medicinal properties

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    BACKGROUND The sclerotium of Lignosus rhinocerotis (Cooke) Ryvarden or Tiger milk mushroom (Polyporales, Basidiomycota) is a valuable folk medicine for indigenous peoples in Southeast Asia. Despite the increasing interest in this ethnobotanical mushroom, very little is known about the molecular and genetic basis of its medicinal and nutraceutical properties. RESULTS The de novo assembled 34.3 Mb L. rhinocerotis genome encodes 10,742 putative genes with 84.30% of them having detectable sequence similarities to others available in public databases. Phylogenetic analysis revealed a close evolutionary relationship of L. rhinocerotis to Ganoderma lucidum, Dichomitus squalens, and Trametes versicolor in the core polyporoid clade. The L. rhinocerotis genome encodes a repertoire of enzymes engaged in carbohydrate and glycoconjugate metabolism, along with cytochrome P450s, putative bioactive proteins (lectins and fungal immunomodulatory proteins) and laccases. Other genes annotated include those encoding key enzymes for secondary metabolite biosynthesis, including those from polyketide, nonribosomal peptide, and triterpenoid pathways. Among them, the L. rhinocerotis genome is particularly enriched with sesquiterpenoid biosynthesis genes. CONCLUSIONS The genome content of L. rhinocerotis provides insights into the genetic basis of its reported medicinal properties as well as serving as a platform to further characterize putative bioactive proteins and secondary metabolite pathway enzymes and as a reference for comparative genomics of polyporoid fungi.This research is supported by High Impact Research Grant UM.C/625/1/HIR/ MoE/E20040-20001 from the University of Malaya/Ministry of Education, Malaysia. H-YYY is supported by the postgraduate research grant (PPP) PV024/ 2012A from University of Malaya, Malaysia. Y-HC is a recipient of Australian Research Council Discovery Early Career Researcher Award (ARC DECRA)

    The genome of the Tiger Milk mushroom, Lignosus rhinocerotis, provides insights into the genetic basis of its medicinal properties

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    BACKGROUND: The sclerotium of Lignosus rhinocerotis (Cooke) Ryvarden or Tiger milk mushroom (Polyporales, Basidiomycota) is a valuable folk medicine for indigenous peoples in Southeast Asia. Despite the increasing interest in this ethnobotanical mushroom, very little is known about the molecular and genetic basis of its medicinal and nutraceutical properties. RESULTS: The de novo assembled 34.3 Mb L. rhinocerotis genome encodes 10,742 putative genes with 84.30% of them having detectable sequence similarities to others available in public databases. Phylogenetic analysis revealed a close evolutionary relationship of L. rhinocerotis to Ganoderma lucidum, Dichomitus squalens, and Trametes versicolor in the core polyporoid clade. The L. rhinocerotis genome encodes a repertoire of enzymes engaged in carbohydrate and glycoconjugate metabolism, along with cytochrome P450s, putative bioactive proteins (lectins and fungal immunomodulatory proteins) and laccases. Other genes annotated include those encoding key enzymes for secondary metabolite biosynthesis, including those from polyketide, nonribosomal peptide, and triterpenoid pathways. Among them, the L. rhinocerotis genome is particularly enriched with sesquiterpenoid biosynthesis genes. CONCLUSIONS: The genome content of L. rhinocerotis provides insights into the genetic basis of its reported medicinal properties as well as serving as a platform to further characterize putative bioactive proteins and secondary metabolite pathway enzymes and as a reference for comparative genomics of polyporoid fungi. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-635) contains supplementary material, which is available to authorized users

    WOOD PLASTIC COMPOSITES MADE FROM CORN HUSK FIBER AND RECYCLED POLYSTYRENE FOAM

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    This research is a preliminary study on the preparation of wood plastic composites (WPC) from corn husk fiber (CHF) and recycled polystyrene foam (rPS). The effects of fiber content and alkaline treatment on tensile, thermal, water absorption and morphological properties of the composites were investigated. The rPS/CHF composites were prepared using melt compounding and compression moulding processes. The results showed that an increase of fiber content increased the tensile strength, modulus, and thermal stability (Td50%) of composites. However, the water absorption of composites increased vastly as the fiber content increases. The addition of more fiber also caused an earlier thermal degradation to composites. Alkaline treatment has improved the tensile strength, modulus, thermal stability (Td10%), and also reduced water absorption of rPS/CHF composites. The WPS prepared from rPS and treated CHF shows better tensile and thermal properties with lower water absorption

    Single layer microwave absorber based on rice husk-mwcnts composites

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    In this paper, rice husk (RH) and multi-walled carbon nanotubes (MWCNTs) composite have been fabricated as single layer microwave absorber. The MWCNTs with various weight ratio composites with RH have been prepared. Three different weight ratio 3 wt% MWCNTs, 5 wt% MWCNTs, and 15 wt% MWCNTs of the RH-CNTs have been designed and fabricated. Moreover, the dielectric properties of different RH-CNTs specimens have been verified by using rectangular waveguide transmission line technique. Furthermore, the microwave absorption of these RH-CNTs has been analyzed using free space measurement and CST Microwave Studio (CST-MWS). The dielectric properties and microwave absorption of different RH-CNTs were investigated in 8.2-12.4 GHz (X-band). From the measurement, the dielectric properties parameter of RH-CNTs is analyzed. The dielectric constant and loss factor of the RH-CNTs composite increases with increasing of MWCNTs weight ratio. However, the magnetic properties of RH-CNTs remain constant, ur= 1-j0. The measurement and simulation result show that such RH-CNTs composites has excellent microwave absorption up to 33 dB in a certain frequency rang

    Specific, sensitive and rapid detection of human plasmodium knowlesi infection by loop-mediated isothermal amplification (LAMP) in blood samples

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    <p>Abstract</p> <p>Background</p> <p>The emergence of <it>Plasmodium knowlesi </it>in humans, which is in many cases misdiagnosed by microscopy as <it>Plasmodium malariae </it>due to the morphological similarity has contributed to the needs of detection and differentiation of malaria parasites. At present, nested PCR targeted on <it>Plasmodium </it>ssrRNA genes has been described as the most sensitive and specific method for Plasmodium detection. However, this method is costly and requires trained personnel for its implementation. Loop-mediated isothermal amplification (LAMP), a novel nucleic acid amplification method was developed for the clinical detection of <it>P. knowlesi</it>. The sensitivity and specificity of LAMP was evaluated in comparison to the results obtained via microscopic examination and nested PCR.</p> <p>Methods</p> <p>LAMP assay was developed based on <it>P. knowlesi </it>genetic material targeting the apical membrane antigen-1 (AMA-1) gene. The method uses six primers that recognize eight regions of the target DNA and it amplifies DNA within an hour under isothermal conditions (65°C) in a water-bath.</p> <p>Results</p> <p>LAMP is highly sensitive with the detection limit as low as ten copies for AMA-1. LAMP detected malaria parasites in all confirm cases (n = 13) of <it>P. knowlesi </it>infection (sensitivity, 100%) and none of the negative samples (specificity, 100%) within an hour. LAMP demonstrated higher sensitivity compared to nested PCR by successfully detecting a sample with very low parasitaemia (< 0.01%).</p> <p>Conclusion</p> <p>With continuous efforts in the optimization of this assay, LAMP may provide a simple and reliable test for detecting <it>P. knowlesi </it>malaria parasites in areas where malaria is prevalent.</p

    Low-frequency optical phonon modes and carrier mobility in the halide perovskite CH3NH3PbBr3 using terahertz time-domain spectroscopy

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    As a light absorber in photovoltaic applications, hybrid organic-inorganic halide perovskites should have long and balanced diffusion lengths for both the separated electrons and holes before recombi- nation, which necessitates high carrier mobility. In polar semiconductors, the room-temperature carrier mobility is often limited by the scattering between carriers and the lowest-frequency optical phonon modes. Using terahertz time-domain spectroscopy, we examine the temperature evolution of these phonon modes in CH 3 NH 3 PbBr 3 and obtained high carrier mobility values using Feynman’s polaron theory. This method allows us to estimate the upper limit of carrier mobilities without the need to create photogenerated free carriers, and can be applied to other heteropolar semiconductor systems with large polarons

    Heterologous expression of cytotoxic sesquiterpenoids from the medicinal mushroom Lignosus rhinocerotis in yeast

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    Background: Genome mining facilitated by heterologous systems is an emerging approach to access the chemical diversity encoded in basidiomycete genomes. In this study, three sesquiterpene synthase genes, GME3634, GME3638, and GME9210, which were highly expressed in the sclerotium of the medicinal mushroom Lignosus rhinocerotis, were cloned and heterologously expressed in a yeast system. Results: Metabolite profile analysis of the yeast culture extracts by GC-MS showed the production of several sesquiterpene alcohols (C 15 H 26 O), including cadinols and germacrene D-4-ol as major products. Other detected sesquiterpenes include selina-6-en-4-ol, ß-elemene, ß-cubebene, and cedrene. Two purified major compounds namely (+)-torreyol and a-cadinol synthesised by GME3638 and GME3634 respectively, are stereoisomers and their chemical structures were confirmed by 1 H and 13 C NMR. Phylogenetic analysis revealed that GME3638 and GME3634 are a pair of orthologues, and are grouped together with terpene synthases that synthesise cadinenes and related sesquiterpenes. (+)-Torreyol and a-cadinol were tested against a panel of human cancer cell lines and the latter was found to exhibit selective potent cytotoxicity in breast adenocarcinoma cells (MCF7) with IC 50 value of 3.5 ± 0.58 µg/ml while a-cadinol is less active (IC 50 = 18.0 ± 3.27 µg/ml). Conclusions: This demonstrates that yeast-based genome mining, guided by transcriptomics, is a promising approach for uncovering bioactive compounds from medicinal mushrooms
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