Displaying publications 1 - 20 of 54 in total

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  1. Fung SY, Tan NH
    Indian J. Exp. Biol., 2013 Dec;51(12):1063-9.
    PMID: 24579371
    The major hemorrhagin from C. purpureomaculatus (mangrove pit viper) venom was purified to homogeneity and termed Maculatoxin. Maculatoxin has a molecular weight of 38 kDa as determined by SDS-PAGE. It is an acidic protein (pI= 4.2) and exhibited proteolytic and hemorrhagic activities (MHD10 = 0.84 microg in mice) but was not lethal to mice at a dose of 1 microg/g. The hemorrhagic activity of Maculatoxin was completely inactivated by EDTA and partially inhibited by ATP and citrate. The N-terminal sequence of Maculatoxin (TPEQQRFPPTYIDLGIFVDHGMYAT) shares a significant degree of homology with the metalloprotease domain of other venom hemorrhagins. Indirect ELISA showed anti-Maculatoxin cross reacted with protein components of many snake venoms. In the double-sandwich ELISA, however, anti-Maculatoxin cross-reacted only with venoms of certain species of the Trimeresurus (Asia lance-head viper) complex, and the results support the recent proposed taxonomy changes concerning the Trimeresurus complex.
  2. Fung SY, Lee ML, Tan NH
    Toxicon, 2015 Mar;96:38-45.
    PMID: 25615711 DOI: 10.1016/j.toxicon.2015.01.012
    Snake venom LAAOs have been reported to exhibit a wide range of pharmacological activities, including cytotoxic, edema-inducing, platelet aggregation-inducing/platelet aggregation-inhibiting, bactericidal and antiviral activities. A heat-stable form of l-amino acid oxidase isolated from king cobra (Ophiophagus hannah) venom (OH-LAAO) has been shown to exhibit very potent cytotoxicity against human tumorigenic cells but not in their non-tumorigenic counterparts, and the cytotoxicity was due to the apoptosis-inducing effect of the enzyme. In this work, the molecular mechanism of cell death induced by OH-LAAO was investigated. The enzyme exerts its apoptosis-inducing effect presumably via both intrinsic and extrinsic pathways as suggested by the increase in caspase-8 and -9 activities. Oligonucleotide microarray analysis showed that the expression of a total of 178 genes was significantly altered as a result of oxidative stress induced by the hydrogen peroxide generated by the enzyme. Of the 178 genes, at least 27 genes are involved in apoptosis and cell death. These alterations of gene expression was presumably caused by the direct cytotoxic effect of H2O2 generated during the enzymatic reaction, as well as the non-specific oxidative modifications of signaling molecules that eventually lead to apoptosis and cell death. The very substantial up-regulation of cytochrome P450 genes may also contribute to the potent cytotoxic action of OH-LAAO by producing excessive reactive oxygen species (ROS). In conclusion, the potent apoptosis inducing activity of OH-LAAO was likely due to the direct cytotoxic effect of H2O2 generated during the enzymatic reaction, as well as the non-specific oxidation of signalling molecules.
  3. Fung SY, Tan NH, Sim SM
    Trop Biomed, 2010 Dec;27(3):366-72.
    PMID: 21399576 MyJurnal
    The protective effects of Mucuna pruriens seed extract (MPE) against the cardio-respiratory depressant and neuromuscular paralytic effects induced by injection of Calloselasma rhodostoma (Malayan pit viper) venom in anaesthetized rats were investigated. While MPE pretreatment did not reverse the inhibitory effect of the venom on the gastrocnemius muscle excitability, it significantly attenuated the venom-induced cardio-respiratory depressant effects (p < 0.05). The protection effects may have an immunological mechanism, as indicated by the presence of several proteins in the venom that are immunoreactive against anti-MPE. However, we cannot rule out the possibility that the pretreatment may exert a direct, non-immunological protective action against the venom.
  4. Tan KY, Tan CH, Fung SY, Tan NH
    J Proteomics, 2015 Apr 29;120:105-25.
    PMID: 25748141 DOI: 10.1016/j.jprot.2015.02.012
    Previous studies showed that venoms of the monocled cobra, Naja kaouthia from Thailand and Malaysia are substantially different in their median lethal doses. The intraspecific venom variations of N. kaouthia, however, have not been fully elucidated. Here we investigated the venom proteomes of N. kaouthia from Malaysia (NK-M), Thailand (NK-T) and Vietnam (NK-V) through reverse-phase HPLC, SDS-PAGE and tandem mass spectrometry. The venom proteins comprise 13 toxin families, with three-finger toxins being the most abundant (63-77%) and the most varied (11-18 isoforms) among the three populations. NK-T has the highest content of neurotoxins (50%, predominantly long neurotoxins), followed by NK-V (29%, predominantly weak neurotoxins and some short neurotoxins), while NK-M has the least (18%, some weak neurotoxins but less short and long neurotoxins). On the other hand, cytotoxins constitute the main bulk of toxins in NK-M and NK-V venoms (up to 45% each), but less in NK-T venom (27%). The three venoms show different lethal potencies that generally reflect the proteomic findings. Despite the proteomic variations, the use of Thai monovalent and Neuro polyvalent antivenoms for N. kaouthia envenomation in the three regions is appropriate as the different venoms were neutralized by the antivenoms albeit at different degrees of effectiveness.
  5. Yap MK, Fung SY, Tan KY, Tan NH
    Acta Trop., 2014 May;133:15-25.
    PMID: 24508616 DOI: 10.1016/j.actatropica.2014.01.014
    The proteome of Naja sumatrana (Equatorial spitting cobra) venom was investigated by shotgun analysis and a combination of ion-exchange chromatography and reverse phase HPLC. Shotgun analysis revealed the presence of 39 proteins in the venom while the chromatographic approach identified 37 venom proteins. The results indicated that, like other Asiatic cobra venoms, N. sumatrana contains large number of three finger toxins and phospholipases A2, which together constitute 92.1% by weight of venom protein. However, only eight of the toxins can be considered as major venom toxins. These include two phospholipases A2, three neurotoxins (two long neurotoxins and a short neurotoxin) and three cardiotoxins. The eight major toxins have relative abundance of 1.6-27.2% venom proteins and together account for 89.8% (by weight) of total venom protein. Other venom proteins identified include Zn-metalloproteinase-disintegrin, Thaicobrin, CRISP, natriuretic peptide, complement depleting factors, cobra venom factors, venom nerve growth factor and cobra serum albumin. The proteome of N. sumatrana venom is similar to proteome of other Asiatic cobra venoms but differs from that of African spitting cobra venom. Our results confirm that the main toxic action of N. sumatrana venom is neurotoxic but the large amount of cardiotoxins and phospholipases A2 are likely to contribute significantly to the overall pathophysiological action of the venom. The differences in toxin distribution between N. sumatrana venom and African spitting cobra venoms suggest possible differences in the pathophysiological actions of N. sumatrana venom and the African spitting cobra venoms, and explain why antivenom raised against Asiatic cobra venom is not effective against African spitting cobra venoms.
  6. Tang EL, Rajarajeswaran J, Fung SY, Kanthimathi MS
    PMID: 24517259 DOI: 10.1186/1472-6882-13-347
    Coriandrum sativum is a popular culinary and medicinal herb of the Apiaceae family. Health promoting properties of this herb have been reported in pharmacognostical, phytochemical and pharmacological studies. However, studies on C. sativum have always focused on the aerial parts of the herb and scientific investigation on the root is limited. The aim of this research was to investigate the antioxidant and anticancer activities of C. sativum root, leaf and stem, including its effect on cancer cell migration, and its protection against DNA damage, with special focus on the roots.
  7. Yap MK, Tan NH, Sim SM, Fung SY
    Toxicon, 2013 Jun;68:18-23.
    PMID: 23537711 DOI: 10.1016/j.toxicon.2013.02.017
    Existing protocols for antivenom treatment of snake envenomations are generally not well optimized due partly to inadequate knowledge of the toxicokinetics of venoms. The toxicokinetics of Naja sputatrix (Javan spitting cobra) venom was investigated following intravenous and intramuscular injections of the venom into rabbits using double-sandwich ELISA. The toxicokinetics of the venom injected intravenously fitted a two-compartment model. When the venom was injected intramuscularly, the serum concentration-time profile exhibited a more complex absorption and/or distribution pattern. Nevertheless, the terminal half-life, volume of distribution by area and systemic clearance of the venom injected intramuscularly were not significantly different (p > 0.05) from that of the venom injected intravenously. The systemic bioavailability of the venom antigens injected by intramuscular route was 41.7%. Our toxicokinetic finding is consistent with other reports, and may indicate that some cobra venom toxins have high affinity for the tissues at the site of injection. Our results suggest that the intramuscular route of administration doesn't significantly alter the toxicokinetics of N. sputatrix venom although it significantly reduces the systemic bioavailability of the venom.
  8. Leong PK, Tan NH, Fung SY, Sim SM
    Trans. R. Soc. Trop. Med. Hyg., 2012 Dec;106(12):731-7.
    PMID: 23062608 DOI: 10.1016/j.trstmh.2012.07.009
    Cross neutralisation of venoms by antivenom raised against closely-related species has been well documented. The spectrum of paraspecific protection of antivenom raised against Asiatic Naja and Bungarus (krait) venoms, however, has not been fully investigated. In this study, we examined the cross neutralisation of venoms from common Southeast Asian cobras and kraits by two widely used polyvalent antivenoms produced in India: Vins Polyvalent Antivenom (VPAV) and Bharat Polyvalent Antivenom (BPAV), using both in vitro and in vivo mouse protection assays. BPAV was only moderately effective against venoms of N. kaouthia (Thailand) and N. sumatrana, and either very weakly effective or totally ineffective against the other cobra and krait venoms. VPAV, on the other hand, neutralised effectively all the Southeast Asian Naja venoms tested, as well as N. naja, B. candidus and Ophiophagus hannah venoms, but the potency ranges from effective to weakly effective. In an in vivo rodent model, VPAV also neutralised the lethality of venoms from Asiatic Naja and B. candidus. In anesthetised rat studies, both antivenoms effectively protected against the N. kaouthia venom-induced cardio-respiratory depressant and neuromuscular blocking effects. Overall, our results suggest that VPAV could be used as alternative antivenom for the treatment of elapid envenomation in Southeast Asian regions including Malaysia, Thailand and certain regions of Indonesia.
  9. Tan CH, Tan KY, Fung SY, Tan NH
    BMC Genomics, 2015;16:687.
    PMID: 26358635 DOI: 10.1186/s12864-015-1828-2
    The king cobra (Ophiophagus hannah) is widely distributed throughout many parts of Asia. This study aims to investigate the complexity of Malaysian Ophiophagus hannah (MOh) venom for a better understanding of king cobra venom variation and its envenoming pathophysiology. The venom gland transcriptome was investigated using the Illumina HiSeq™ platform, while the venom proteome was profiled by 1D-SDS-PAGE-nano-ESI-LCMS/MS.
  10. Tan NH, Fung SY, Yap YH
    PMID: 21983189 DOI: 10.1016/j.cbpb.2011.09.009
    A thrombin-like enzyme (termed albolabrase) was isolated in purified form from the venom of Cryptelytrops albolabris (white-lipped tree viper) using high performance anion ion exchange and gel filtration chromatography. The molecular mass of albolabrase was 33.7 kDa as determined by SDS-PAGE and 35.8 kDa as determined by Superose gel filtration chromatography. The N-terminal sequence was determined to be VVGGDECNINE which is homologous to many snake venom thrombin-like enzymes. Albolabrase exhibits both arginine ester hydrolase and arginine amidase activities and the enzyme is fastidious towards tripeptide chromogenic anilide substrates. The fibrinogen clotting activity was optimum at 3mg/mL bovine fibrinogen, and showed distinct species differences in the following decreasing order: bovine fibrinogen>dog fibrinogen≈human fibrinogen>goat fibrinogen. The enzyme failed to clot both rabbit and cat fibrinogens. Reversed-phase HPLC analysis on the breakdown products of fibrinogenolytic action of albolabrase indicated that the enzyme belongs to the AB class of snake venom thrombin-like enzyme. In the indirect ELISA, IgG anti-albolabrase reacted extensively with most crotalid venoms, except with Tropidolaemus wagleri and Calloselasma rhodostoma venoms. The double sandwich ELISA, however, showed that anti-albolabrase reacted strongly only with venoms from the Trimeresurus complex, and that the results support the proposed new taxonomy changes concerning the Trimeresurus complex.
  11. Fung SY, Tan NH, Sim SM, Aguiyi JC
    PMID: 21785646 DOI: 10.1155/2012/486390
    Mucuna pruriens Linn. (velvet bean) has been used by native Nigerians as a prophylactic for snakebite. Rats pretreated with M. pruriens seed extract (MPE) have been shown to protect against the lethal and cardiovascular depressant effects of Naja sputatrix (Javan spitting cobra) venoms, and the protective effect involved immunological neutralization of the venom toxins. To investigate further the mechanism of the protective effect of MPE pretreatment against cobra venom toxicity, the actions of Naja sputatrix venom on spontaneously beating rat atria and aortic rings isolated from both MPE pretreated and untreated rats were studied. Our results showed that the MPE pretreatment conferred protection against cobra venom-induced depression of atrial contractility and atrial rate in the isolated atrial preparations, but it had no effect on the venom-induced contractile response of aortic ring preparation. These observations suggested that the protective effect of MPE pretreatment against cobra venom toxicity involves a direct protective action of MPE on the heart function, in addition to the known immunological neutralization mechanism, and that the protective effect does not involve action on blood vessel contraction. The results also suggest that M. pruriens seed may contain novel cardioprotective agent with potential therapeutic value.
  12. Lee ML, Tan NH, Fung SY, Sekaran SD
    PMID: 21059402 DOI: 10.1016/j.cbpc.2010.11.001
    The major l-amino acid oxidase (LAAO, EC 1.4.3.2) of king cobra (Ophiophagus hannah) venom is known to be an unusual form of snake venom LAAO as it possesses unique structural features and unusual thermal stability. The antibacterial effects of king cobra venom LAAO were tested against several strains of clinical isolates including Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli using broth microdilution assay. For comparison, the antibacterial effects of several antibiotics (cefotaxime, kanamycin, tetracycline, vancomycin and penicillin) were also examined using the same conditions. King cobra venom LAAO was very effective in inhibiting the two Gram-positive bacteria (S. aureus and S. epidermidis) tested, with minimum inhibitory concentration (MIC) of 0.78μg/mL (0.006μM) and 1.56μg/mL (0.012μM) against S. aureus and S. epidermidis, respectively. The MICs are comparable to the MICs of the antibiotics tested, on a weight basis. However, the LAAO was only moderately effective against three Gram-negative bacteria tested (P. aeruginosa, K. pneumoniae and E. coli), with MIC ranges from 25 to 50μg/mL (0.2-0.4μM). Catalase at the concentration of 1mg/mL abolished the antibacterial effect of LAAO, indicating that the antibacterial effect of the enzyme involves generation of hydrogen peroxide. Binding studies indicated that king cobra venom LAAO binds strongly to the Gram-positive S. aureus and S. epidermidis, but less strongly to the Gram-negative E. coli and P. aeruginosa, indicating that specific binding to bacteria is important for the potent antibacterial activity of the enzyme.
  13. Kong BH, Tan NH, Fung SY, Pailoor J
    Front Pharmacol, 2016;7:246.
    PMID: 27555822 DOI: 10.3389/fphar.2016.00246
    Lignosus also known as "Tiger Milk Mushroom," is classified in the family Polyporaceae and mainly consumed for its medicinal properties in Southeast Asia and China. The sclerotium is known as the part with medicinal value and often used by the natives to treat a variety of ailments. Lignosus tigris Chon S. Tan, one of the species of the Malaysia Tiger Milk mushroom, has recently been successfully cultivated in laboratory. Earlier studies have demonstrated the L. tigris cultivar E sclerotia exhibited beneficial biomedicinal properties. This study evaluated the potential toxicity of L. tigris E sclerotia in a 28-day sub-acute oral administration in Sprague Dawley (SD) rats. L. tigris E sclerotial powder was administered orally at three different doses of 250, 500, and 1000 mg/kg to the SD rats once daily, consecutively for 28-days. Body weight of the rats was recorded and general behavior, adverse effects, and mortality were observed daily throughout the experimental period. At the end of the experiment, blood hematology and biochemistry, relative organ weights, and histopathological analysis were performed. Results showed that there were no mortality nor signs of toxicity throughout the 28-day sub-acute toxicity study. Oral administration of the L. tigris E sclerotial powder at daily dose up to 1000 mg/kg had no significant effects in body weight, relative organ weight, blood hematological and biochemistry, gross pathology, and histopathology of the organs. L. tigris E sclerotial powder did not cause any treatment-related adverse effect in the rats at different treatment dosages up to 1000 mg/kg. As the lethal dose for the rats is above 1000 mg/kg, the no-observed-adverse-effect level (NOAEL) dose is more than 1000 mg/kg.
  14. Tang EL, Tan CH, Fung SY, Tan NH
    J Proteomics, 2016 10 04;148:44-56.
    PMID: 27418434 DOI: 10.1016/j.jprot.2016.07.006
    The venom of Malayan pit viper (Calloselasma rhodostoma) is highly toxic but also valuable in drug discovery. However, a comprehensive proteome of the venom that details its toxin composition and abundance is lacking. This study aimed to unravel the venom complexity through a multi-step venomic approach. At least 96 distinct proteins (29 basic, 67 acidic) in 11 families were identified from the venom. The venom consists of mainly snake venom metalloproteinases (SVMP, 41.17% of total venom proteins), within which the P-I (kistomin, 20.4%) and P-II (rhodostoxin, 19.8%) classes predominate. This is followed by C-type lectins (snaclec, 26.3%), snake venom serine protease (SVSP, 14.9%), L-amino acid oxidase (7.0%), phospholipase A2 (4.4%), cysteine-rich secretory protein (2.5%), and five minor toxins (nerve growth factor, neurotrophin, phospholipase B, 5' nucleotidase and phosphodiesterase, totaling 2.6%) not reported in the proteome hitherto. Importantly, all principal hemotoxins unveiled correlate with the syndrome: SVSP ancrod causes venom-induced consumptive coagulopathy, aggravated by thrombocytopenia caused by snaclec rhodocytin, a platelet aggregation inducer, while P-II rhodostoxin mediates hemorrhage, exacerbated by P-I kistomin and snaclec rhodocetin that inhibit platelet plug formation. These toxins exist in multiple isoforms and/or complex subunits, deserving further characterization for the development of an effective, polyspecific regional antivenom.

    BIOLOGICAL SIGNIFICANCE: Advents in proteomics and bioinformatics have vigorously propelled the scientific discoveries of toxins from various lineages of venomous snakes. The Malayan pit viper, Calloselasma rhodostoma, is a medically important species in Southeast Asia as its bite can cause envenomation, while the venom is also a source of bioactive compounds for drug discovery. Detailed profiling of the venom, however, is inadequate possibly due to the complex nature of the venom and technical limitation in separating the constituents into details. Integrating a multi-step fractionation method, this study successfully revealed a comprehensive and quantitative profile of the composition of the venom of this medically important venomous snake. The relative abundance of the various venom proteins is determined in a global profile, providing useful information for understanding the pathogenic roles of the different toxins in C. rhodostoma envenomation. Notably, the principal hemotoxins were identified in great details, including the variety of toxin subunits and isoforms. The findings indicate that these toxins are the principal targets for effective antivenom neutralization, and should be addressed in the production of a pan-regional polyspecific antivenom. In addition, minor toxin components not reported previously in the venom were also detected in this study, enriching the current toxin database for the venomous snakes.

  15. Fung SY, Lee SS, Tan NH, Pailoor J
    J Ethnopharmacol, 2017 Jul 12;206:236-244.
    PMID: 28587826 DOI: 10.1016/j.jep.2017.05.037
    ETHNOPHARMACOLOGICAL RELEVANCE: Ophiocordyceps sinensis (Berk.) G.H. Sung, J.M. Sung, Hywel-Jones & Spatafora is one of the most renowned traditional Chinese medicine used as tonic, renal, respiratory and reproductive health, promote longevity and overall improvement in quality of life. Natural production of O. sinensis is limited due to its extreme specificity in host range and confined geographic distribution. Therefore, cultivation of the fungus was developed to meet high demand for commercialization as nutraceutical. O. sinensis fruiting body has recently been successfully cultivated in large scale using rice based solid medium, providing wider source options for consumers and scientific researchers.

    AIMS OF THE STUDY: The present study aims to establish safety profile for the consumption of cultivated fruiting body of O. sinensis (FBOS) by 28-days sub-acute toxicity study in Sprague Dawley rats.

    MATERIALS AND METHODS: Rats were orally administered with cultivated FBOS at three graded doses (250, 500 and 1000mg/kg), once daily for 28 consecutive days. Control group received distilled water. General observations (gross behavioral changes and toxic symptoms) and body weight of each animal were monitored daily. Haematological, serum biochemical and histopathological analysis were carried out at the end of the experiment (Day 29).

    RESULTS: No behavioral changes, toxic symptoms or death was observed in rats throughout the dosing period. Cultivated FBOS treatment up to 1000mg/kg did not cause any adverse effect on the growth of the animals. Results from haematology and serum biochemistry revealed no toxic effect following cultivated FBOS treatment at three graded doses for 28 days. In addition, no treatment related histopathological changes were noted in heart, spleen, kidney, lung and liver of the animals.

    CONCLUSION: The present study revealed that oral administration of cultivated FBOS for 28 days, at dosage up to 1000mg/kg did not pose toxicological concern in rats. Therefore, the no-observed-adverse-effect level (NOAEL) dose of cultivated FBOS in 28-days subacute toxicity study is higher than 1000mg/kg.

  16. Lee SS, Tan NH, Pailoor J, Fung SY
    Front Pharmacol, 2017;8:594.
    PMID: 28919858 DOI: 10.3389/fphar.2017.00594
    Twenty-eight days subacute toxicity studies performed in rats using sclerotial powder of Lignosus cameronensis cultivar was conducted to assess its safety for consumption prior to other scientific investigations on its medicinal benefits, nutraceutical or pharmaceutical application of the mushroom. The study was conducted at 250, 500, and 1000 mg/kg sclerotial powder of L. cameronensis cultivar (n = 5 for each respective dose, on both male and female groups) while control groups received only distilled water. At the end of the study (29th day), the animals were sacrificed followed by blood and organs collection for analysis. Subacute toxicity studies done shows that sclerotial powder of L. cameronensis cultivar at 250, 500, and 1000 mg/kg did not induce treatment related changes on behavioral patterns, gross physical appearance, growth pattern, body weight gain, values of hematological and clinical biochemical panels as well as histopathological findings on kidney, spleen, heart, lung and liver of the experimental rats. The no-observed-adverse-effect level dose for sclerotial powder of L. cameronensis cultivar in 28-days sub-acute toxicity study is determined to be 1000 mg/kg.
  17. Tang ELH, Tan NH, Fung SY, Tan CH
    Toxicon, 2019 Aug 22;169:91-102.
    PMID: 31445943 DOI: 10.1016/j.toxicon.2019.08.004
    The intraspecific geographical venom variations of Calloselasma rhodostoma from Malaysia (CR-M), Indonesia (CR-I), Thailand (CR-T) and Vietnam (CR-V) were investigated through 1D SDS-PAGE and nano-ESI-LCMS/MS. The venom antigenicity, procoagulant activities and neutralization using Thai C. rhodostoma Monovalent Antivenom (CRMAV) were also investigated. SDS-PAGE patterns of the venoms were relatively similar with minor variations. Proteomic analysis revealed that snake venom metalloproteinases (SVMPs, particularly P-I class), serine proteases (SVSPs) and snaclecs dominated the venom protein composition (68.96-81.80%), followed by L-amino acid oxidase (LAAO) and phospholipase A2 (PLA2) (7.37-11.08% and 5.18-13.81%, respectively), corroborating C. rhodostoma envenoming effects (hemorrhage, consumptive coagulopathy, thrombocytopenia and local tissue necrosis). Other proteins of lower abundances (2.82-9.13%) identified include cysteine-rich secretory proteins (CRISP), phospholipase B, phosphodiesterase, nerve growth factor, 5'-nucleotidase, aminopeptidase and hyaluronidase. All four venoms exhibited strong procoagulant effects which were neutralized by CRMAV to different extents. CRMAV immunoreactivity was high toward venoms of CR-M, CR-I and CR-T but relatively low for CR-V venom. Among the venom samples from different locales, CR-V venom proteome has the smallest SVMP composition while SVSP, PLA2 and phosphodiesterase were more abundant in the venom. These variations in C. rhodostoma venom protein composition could partly explain the differences seen in immunoreactivity. (198 words).
  18. Tan CH, Tan NH, Sim SM, Fung SY, Gnanathasan CA
    Toxicon, 2015 Jan;93:164-70.
    PMID: 25451538 DOI: 10.1016/j.toxicon.2014.11.231
    The hump-nosed pit viper, Hypanle hypnale, contributes to snakebite mortality and morbidity in Sri Lanka. Studies showed that the venom is hemotoxic and nephrotoxic, with some biochemical and antigenic properties similar to the venom of Calloselasma rhodostoma (Malayan pit viper). To further characterize the complexity composition of the venom, we investigated the proteome of a pooled venom sample from >10 Sri Lankan H. hypnale with reverse-phase high performance liquid chromatography (rp-HPLC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and peptide sequencing (tandem mass-spectrometry and/or N-terminal sequencing). The findings ascertained that two phospholipase A2 subtypes (E6-PLA2, W6-PLA2) dominate the toxin composition by 40.1%, followed by snake venom metalloproteases (36.9%), l-amino acid oxidase (11.9%), C-type lectins (5.5%), serine proteases (3.3%) and others (2.3%). The presence of the major toxins correlates with the venom's major pathogenic effects, indicating these to be the principal target toxins for antivenom neutralization. This study supports the previous finding of PLA2 dominance in the venom but diverges from the view that H. hypnale venom has low expression of large enzymatic toxins. The knowledge of the composition and abundance of toxins is essential to elucidate the pathophysiology of H. hypnale envenomation and to optimize antivenom formulation in the future.
  19. Yap HY, Fung SY, Ng ST, Tan CS, Tan NH
    Int J Med Sci, 2015;12(1):23-31.
    PMID: 25552915 DOI: 10.7150/ijms.10019
    Lignosus rhinocerotis (Cooke) Ryvarden (Polyporales, Basidiomycota), also known as the tiger milk mushroom, has received much interest in recent years owing to its wide-range ethnobotanical uses and the recent success in its domestication. The sclerotium is the part with medicinal value. Using two-dimensional gel electrophoresis coupled with mass spectrometry analysis, a total of 16 non-redundant, major proteins were identified with high confidence level in L. rhinocerotis sclerotium based on its genome as custom mapping database. Some of these proteins, such as the putative lectins, immunomodulatory proteins, superoxide dismutase, and aegerolysin may have pharmaceutical potential; while others are involved in nutrient mobilization and the protective antioxidant mechanism in the sclerotium. The findings from this study provide a molecular basis for future research on potential pharmacologically active proteins of L. rhinocerotis.
  20. Lee SS, Tan NH, Fung SY, Sim SM, Tan CS, Ng ST
    PMID: 25256382 DOI: 10.1186/1472-6882-14-359
    The sclerotium of Lignosus rhinocerotis (Cooke) Ryvarden (Tiger Milk mushroom) is used as a traditional medicine to relieve cough, asthma and chronic hepatitis. The traditional uses of the sclerotium are presumably related to its anti-inflammatory effect. The present study was carried out to evaluate the anti-inflammatory activity of the sclerotial powder of L. rhinocerotis (Cooke) Ryvarden (Tiger Milk mushroom) cultivar TM02.
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