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1.
J Food Sci Technol ; 58(6): 2078-2088, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33967306

ABSTRACT

Sea cucumbers are considered healthy and high in nutritive value. Conversely however, limited consumption of sea cucumbers has been reported in many parts of the world. This study was done to produce a ready-to-prepare soup mix incorporating the sea cucumber aiming to popularize the sea cucumber consumption. The highly abundant low-value Bohadschia vitiensis in the coastal waters of Sri Lanka was selected to prepare this soup mix. Fresh B. vitiensis samples (n = 250) were collected from major sea cucumber landing sites of the northwest coast. Out of the seven compositions prepared initially, three compositions; 20%, 40% and 60% were selected. The best composition among these was selected through a sensory test performed using a semi-trained panel (n = 30) at the University of Sri Jayewardenepura, Sri Lanka. The initial chemical and microbial qualities of the selected soup mix were analyzed and the best packaging material was selected. Results showed that the soup mix with 40% sea cucumber flour was the best composition as it reported significantly higher sensory scores than the other two mixes (p ≤ 0.05, Friedman). This soup mix exhibited high protein (21.43 ± 1.21%), low fat (4.98 ± 0.23%) and its oxygen radical absorbance capacity was 1.04 ± 0.13 mg Trolox equivalents/g. Coliforms and Staphylococcus aureus colonies were absent in the soup mix. The total plate count (1.9 × 102 CFU/g), yeast and mold count (0.7 × 102 CFU/g) and the heavy metal contents were within the safe limit for human consumption. The Polyester-Aluminum-PE was selected as the best packaging material which ensured 6 weeks storage time at room temperature.

2.
J Ayurveda Integr Med ; 12(2): 261-268, 2021.
Article in English | MEDLINE | ID: mdl-33731265

ABSTRACT

BACKGROUND: The excessive formation of Advanced Glycation End-products (AGEs) by non-enzymatic glycation mediates many health complications in the human body and the formation of AGEs largely accelerated under the hyperglycaemic condition. OBJECTIVE: The prospect of the study to assess the strength of inhibiting the rapid AGE formations in four Ayurvedic medicinal plants, namely; Salacia reticulata (stems), Syzygium cumini (barks), Artocarpus heterophyllus (mature leaves) and, Cassia auriculata (flowers). MATERIALS AND METHODS: Herbal decoctions of four medicinal plant materials were prepared by simmering with hot water as prescribed by the Ayurvedic medicine. The effectiveness of the decoctions was analyzed in vitro based on their Anti-AGE formation activity, glycation reversing, and anti-oxidant potentials. RESULTS: According to the results, the decoctions of S. reticulata, A. heterophyllus and C. auriculata indicated the strong Anti-AGE forming (IC50: 23.01 ± 2.70, 32.01 ± 2.09, 43.66 ± 2.11 mg/mL, respectively), glycation reversing (EC50: 183.15 ± 7.67, 91.85 ± 1.93, 252.35 ± 4.03 mg/mL, respectively) and antioxidant potentials in terms of total polyphenol content (TPC), total flavonoid content (TFC), ferric ion reducing power (FRAP), ABTS and DPPH radical scavenging activities. However, the decoction of S. cumini reported the significantly high (p < 0.05) Anti-AGE forming, (IC50: 9.75 ± 0.32 mg/mL), glycation reversing (EC50: 66.45 ± 4.51 mg/mL), and antioxidant potentials against the decoctions of the other three plant materials. CONCLUSION: S. cumini bark extract was identified as the best source in controlling the formation of AGEs excessively. Further, the other three plant extracts can also be effectively used as potential therapeutic agents to control the pathological conditions associated with AGEs-mediated health complications.

3.
J Virol ; 89(17): 8783-92, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26063435

ABSTRACT

UNLABELLED: Viruses exploit molecules on the target membrane as receptors for attachment and entry into host cells. Thus, receptor expression patterns can define viral tissue tropism and might to some extent predict the susceptibility of a host to a particular virus. Previously, others and we have shown that respiratory pathogens of the genus Gammacoronavirus, including chicken infectious bronchitis virus (IBV), require specific α2,3-linked sialylated glycans for attachment and entry. Here, we studied determinants of binding of enterotropic avian gammacoronaviruses, including turkey coronavirus (TCoV), guineafowl coronavirus (GfCoV), and quail coronavirus (QCoV), which are evolutionarily distant from respiratory avian coronaviruses based on the viral attachment protein spike (S1). We profiled the binding of recombinantly expressed S1 proteins of TCoV, GfCoV, and QCoV to tissues of their respective hosts. Protein histochemistry showed that the tissue binding specificity of S1 proteins of turkey, quail, and guineafowl CoVs was limited to intestinal tissues of each particular host, in accordance with the reported pathogenicity of these viruses in vivo. Glycan array analyses revealed that, in contrast to the S1 protein of IBV, S1 proteins of enteric gammacoronaviruses recognize a unique set of nonsialylated type 2 poly-N-acetyl-lactosamines. Lectin histochemistry as well as tissue binding patterns of TCoV S1 further indicated that these complex N-glycans are prominently expressed on the intestinal tract of various avian species. In conclusion, our data demonstrate not only that enteric gammacoronaviruses recognize a novel glycan receptor but also that enterotropism may be correlated with the high specificity of spike proteins for such glycans expressed in the intestines of the avian host. IMPORTANCE: Avian coronaviruses are economically important viruses for the poultry industry. While infectious bronchitis virus (IBV), a respiratory pathogen of chickens, is rather well known, other viruses of the genus Gammacoronavirus, including those causing enteric disease, are hardly studied. In turkey, guineafowl, and quail, coronaviruses have been reported to be the major causative agent of enteric diseases. Specifically, turkey coronavirus outbreaks have been reported in North America, Europe, and Australia for several decades. Recently, a gammacoronavirus was isolated from guineafowl with fulminating disease. To date, it is not clear why these avian coronaviruses are enteropathogenic, whereas other closely related avian coronaviruses like IBV cause respiratory disease. A comprehensive understanding of the tropism and pathogenicity of these viruses explained by their receptor specificity and receptor expression on tissues was therefore needed. Here, we identify a novel glycan receptor for enteric avian coronaviruses, which will further support the development of vaccines.


Subject(s)
Coronavirus Infections/veterinary , Coronavirus, Turkey/metabolism , Receptors, Virus/metabolism , Viral Tropism/genetics , Animals , Chickens/virology , Coronavirus Infections/virology , Enteritis/virology , Galactans/metabolism , Infectious bronchitis virus/metabolism , Intestines/virology , Poultry Diseases/virology , Protein Binding/genetics , Turkeys/virology
4.
Virus Res ; 194: 37-48, 2014 Dec 19.
Article in English | MEDLINE | ID: mdl-25451062

ABSTRACT

Avian coronaviruses of the genus Gammacoronavirus are represented by infectious bronchitis virus (IBV), the coronavirus of chicken. IBV causes a highly contagious disease affecting the respiratory tract and, depending on the strain, other tissues including the reproductive and urogenital tract. The control of IBV in the field is hampered by the many different strains circulating worldwide and the limited protection across strains due to serotype diversity. This diversity is believed to be due to the amino acid variation in the S1 domain of the major viral attachment protein spike. In the last years, much effort has been undertaken to address the role of the avian coronavirus spike protein in the various steps of the virus' live cycle. Various models have successfully been developed to elucidate the contribution of the spike in binding of the virus to cells, entry of cell culture cells and organ explants, and the in vivo tropism and pathogenesis. This review will give an overview of the literature on avian coronavirus spike proteins with particular focus on our recent studies on binding of recombinant soluble spike protein to chicken tissues. With this, we aim to summarize the current understanding on the avian coronavirus spike's contribution to host and tissue predilections, pathogenesis, as well as its role in therapeutic and protective interventions.


Subject(s)
Infectious bronchitis virus/physiology , Spike Glycoprotein, Coronavirus/metabolism , Viral Tropism , Virus Attachment , Virus Internalization , Animals , Chickens
5.
Article in English | MEDLINE | ID: mdl-25070289

ABSTRACT

Total mercury (Hg), cadmium (Cd) and lead (Pb) levels were determined in the muscle of four commercialised exported fish species Thunnus albacares (yellowfin tuna), Xiphias gladius (swordfish), Makaira indica (black marlin) and Lutjanus sp (red snapper) collected from the Indian Ocean, Sri Lanka, during July 2009-March 2010 and measured by atomic absorption spectrophotometry. Results show that swordfish (n = 176) contained the highest total Hg (0.90 ± 0.51 mg/kg) and Cd (0.09 ± 0.13 mg/kg) levels, whereas yellowfin tuna (n = 140) contained the highest Pb levels (0.11 ± 0.16 mg/kg). The lowest total Hg (0.16 ± 0.11 mg/kg), Cd (0.01 ± 0.01 mg/kg) and Pb (0.04 ± 0.04 mg/kg) levels were found in red snapper (n = 28). Black marlin (n = 24) contained moderate levels of total Hg (0.49 ± 0.37), Cd (0.02 ± 0.02) and Pb (0.05 ± 0.05). Even though there are some concerns during certain months of the year, this study demonstrates the safety of main export fish varieties in terms of total Hg, Cd and Pb.


Subject(s)
Cadmium/analysis , Fishes , Food Contamination/analysis , Lead/analysis , Mercury/analysis , Muscles/chemistry , Seafood/analysis , Animals , Commerce , Humans , Indian Ocean , Perciformes , Spectrophotometry, Atomic , Sri Lanka , Water Pollutants, Chemical
6.
Sci Rep ; 3: 3058, 2013 Oct 28.
Article in English | MEDLINE | ID: mdl-24162312

ABSTRACT

The emergence of the novel H7N9 influenza A virus (IAV) has caused global concerns about the ability of this virus to spread between humans. Analysis of the receptor-binding properties of this virus using a recombinant protein approach in combination with fetuin-binding, glycan array and human tissue-binding assays demonstrates increased binding of H7 to both α2-6 and α2-8 sialosides as well as reduced binding to α2-3-linked SIAs compared to a closely related avian H7N9 virus from 2008. These differences could be attributed to substitutions Q226L and G186V. Analysis of the enzymatic activity of the neuraminidase N9 protein indicated a reduced sialidase activity, consistent with the reduced binding of H7 to α2-3 sialosides. However, the novel H7N9 virus still preferred binding to α2-3- over α2-6-linked SIAs and was not able to efficiently bind to epithelial cells of human trachea in contrast to seasonal IAV, consistent with its limited human-to-human transmission.


Subject(s)
Fetuins/metabolism , Hemagglutinins/metabolism , Influenza A Virus, H7N9 Subtype/metabolism , Neuraminidase/metabolism , Epithelial Cells/metabolism , Fetuins/chemistry , HEK293 Cells , Hemagglutinins/genetics , Humans , Lung/metabolism , Lung/pathology , Lung/virology , Mutation , Neuraminidase/genetics , Polysaccharides/metabolism , Protein Binding , Recombinant Proteins/biosynthesis , Recombinant Proteins/genetics , Trachea/metabolism , Trachea/pathology , Trachea/virology
7.
Virus Res ; 177(2): 127-37, 2013 Nov 06.
Article in English | MEDLINE | ID: mdl-24041648

ABSTRACT

The spike protein is the major viral attachment protein of the avian coronavirus infectious bronchitis virus (IBV) and ultimately determines viral tropism. The S1 subunit of the spike is assumed to be required for virus attachment. However, we have previously shown that this domain of the embryo- and cell culture adapted Beaudette strain, in contrast to that of the virulent M41 strain, is not sufficient for binding to chicken trachea (Wickramasinghe et al., 2011). In the present study, we demonstrated that the lack of binding of Beaudette S1 was not due to absence of virus receptors on this tissue nor due to the production of S1 from mammalian cells, as S1 proteins expressed from chicken cells also lacked the ability to bind IBV-susceptible embryonic tissue. Subsequently, we addressed the contribution of the S2 subunit of the spike in IBV attachment. Recombinant IBV Beaudette spike ectodomains, comprising the entire S1 domain and the S2 ectodomain, were expressed and analyzed for binding to susceptible embryonic chorio-allantoic membrane (CAM) in our previously developed spike histochemistry assay. We observed that extension of the S1 domain with the S2 subunit of the Beaudette spike was sufficient to gain binding to CAM. A previously suggested heparin sulfate binding site in Beaudette S2 was not required for the observed binding to CAM, while sialic acids on the host tissues were essential for the attachment. To further elucidate the role of S2 the spike ectodomains of virulent IBV M41 and chimeras of M41 and Beaudette were analyzed for their binding to CAM, chicken trachea and mammalian cell lines. While the M41 spike ectodomain showed increased attachment to both CAM and chicken trachea, no binding to mammalian cells was observed. In contrast, Beaudette spike ectodomain had relatively weak ability to bind to chicken trachea, but displayed marked extended host range to mammalian cells. Binding patterns of chimeric spike ectodomains to these tissues and cells indicate that S2 subunits most likely do not contain an additional independent receptor-binding site. Rather, the interplay between S1 and S2 subunits of spikes from the same viral origin might finally determine the avidity and specificity of virus attachment and thus viral host range.


Subject(s)
Coronavirus Infections/virology , Host Specificity , Infectious bronchitis virus/physiology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Virus Attachment , Animals , Cell Line , Chick Embryo , Coronavirus Infections/metabolism , Humans , Infectious bronchitis virus/chemistry , Infectious bronchitis virus/genetics , Protein Structure, Tertiary , Receptors, Virus/metabolism , Spike Glycoprotein, Coronavirus/genetics
8.
Article in English | MEDLINE | ID: mdl-24779931

ABSTRACT

Mercury (Hg) is a global environmental pollutant that has been the cause of many public health concerns. It is transferred through trophic level and bio magnification in the food chain. Total Hg level was measured by cold vapour atomic absorption spectrometry in muscle tissue of 176 Swordfish (Xiphiasgladius) samples ranging from 11.8-112.0 kg total weight and 45-278 cm total length, collected from major fish landing sites in Sri Lanka during July 2009 to March 2010. Total Hg concentration varied between 0.18-2.58 mg/kg wet weight (ww), with a mean value ± standard deviation of 0.90 ± 0.52 mg/kg ww. Of the investigated samples 32% exceeded Hg limits as set by the European Union and Sri Lankan legislation (1 mg/kg, ww). Hg concentration of swordfish showed a significant positive relationship (P value < 0.05) with the fish length and weight. Consequently, consumption of larger fish leads to an increase in the exposure level for consumers.


Subject(s)
Body Size , Mercury/chemistry , Perciformes , Water Pollutants, Chemical/chemistry , Animals , Food Analysis , Food Contamination/analysis , Sri Lanka
9.
J Virol ; 85(17): 8903-12, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21697468

ABSTRACT

The binding of viruses to host cells is the first step in determining tropism and pathogenicity. While avian infectious bronchitis coronavirus (IBV) infection and avian influenza A virus (IAV) infection both depend on α2,3-linked sialic acids, the host tropism of IBV is restricted compared to that of IAV. Here we investigated whether the interaction between the viral attachment proteins and the host could explain these differences by using recombinant spike domains (S1) of IBV strains with different pathogenicities, as well as the hemagglutinin (HA) protein of IAV H5N1. Protein histochemistry showed that S1 of IBV strain M41 and HA of IAV subtype H5N1 displayed sialic acid-dependent binding to chicken respiratory tract tissue. However, while HA bound with high avidity to a broad range of α2,3-linked sialylated glycans, M41 S1 recognized only one particular α2,3-linked disialoside in a glycan array. When comparing the binding of recombinant IBV S1 proteins derived from IBV strains with known differences in tissue tropism and pathogenicity, we observed that while M41 S1 displayed binding to cilia and goblet cells of the chicken respiratory tract, S1 derived from the vaccine strain H120 or the nonvirulent Beaudette strain had reduced or no binding to chicken tissues, respectively, in agreement with the reduced abilities of these viruses to replicate in vivo. While the S1 protein derived from the nephropathogenic IBV strain B1648 also hardly displayed binding to respiratory tract cells, distinct binding to kidney cells was observed, but only after the removal of sialic acid from S1. In conclusion, our data demonstrate that the attachment patterns of the IBV S proteins correlate with the tropisms and pathogenicities of the corresponding viruses.


Subject(s)
Coronavirus/pathogenicity , Host-Pathogen Interactions , Membrane Glycoproteins/metabolism , Receptors, Virus/metabolism , Viral Envelope Proteins/metabolism , Viral Tropism , Animals , Chickens , Hemagglutinin Glycoproteins, Influenza Virus/metabolism , Influenza A Virus, H5N1 Subtype/pathogenicity , Protein Binding , Respiratory Mucosa/virology , Spike Glycoprotein, Coronavirus
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