[Genetic characterization analysis of the whole genome sequence of Coxsackievirus A8 associated with hand, foot and mouth disease in China]

Objective: To study the genomic sequence of Coxsackievirus A8 (CV-A8) associated with hand, foot and mouth disease (HFMD) from 2013 to 2018 in China and to analyze the genetic evolution of each coding region of the full-length genome. Methods: The genome sequences of 11 CV-A8 strains isolated from patients with HFMD in different regions of China from 2013 to 2018 were determined. Sequence alignment and genetic evolution analysis were performed by Sequencher 5.0 and MEGA 7.0 software, etc. Results: Sequence alignment showed that the genome length of 11 CV-A8 strains ranged from 7 393 bp to 7 400 bp. There was no base insertion or deletion in the coding region compared with the prototype strain, but there were individual base insertion or deletion in the non-coding region. The nucleotide and amino acid similarities in the VP1 region of 11 CV-A8 strains were 78.3%-98.6% and 92.6%-99.7%, respectively, and the nucleotide and amino acid sequences identities with the CV-A8 prototype strain were 78.3%-98.2% and 92.6%-99.7%, respectively. Based on the phylogenetic analysis of VP1 region sequences, the CV-A8 can be divided into five genotypes: A, B, C, D and E. The 11 CV-A8 strains in this study belonged to genotypes C (1 strain), D (2 strains) and E (8 strains). The nucleotide and amino acid similarities of 11 CV-A8 full-length genomes were 81.3%-98.8% and 95.9%-99.5%, respectively. The phylogenetic tree of the P2 region showed that the eight E genotypes CV-A8 had the closest evolutionary distance with CV-A4, CV-A14, and CV-A16. The phylogenetic tree of the P3 region showed that the eight E genotypes CV-A8 had a close evolutionary distance with CV-A5, CV-A16, CV-A14 and CV-A4. Conclusions: The 11 CV-A8 stains in this study showed significant intra-genotype diversity in capsid region and recombinant diversity in non-capsid region which indicated that CV-A8 quasispecies were still undergoing dynamics variation. CV-A8 may become an important pathogen of HFMD and the monitoring of CV-A8 needs to be further strengthened.

Dietary polyphenols and type 2 diabetes: current insights and future perspectives

Significant evidence suggests that polyphenol-rich diets have the ability to protect against diabetes. Since several previous reviews focused on the nutrition and health effects including type 2 diabetes of polyphenols in 2007-2008, a number of related original publications have been pulished in this field. This review summarizes important advances related to influence of dietary polyphenols and polyphenol-rich diets on preventing and managing type 2 diabetes, as well as diabetes-mediated changes in bioactivities of dietary polyphenols. It appears that anthocyanins or anthocyanin-rich food intake is related to the risk of type 2 diabetes, but there is no association for other polyphenol subclasses. It is discussed that procyanidins are more active when administered individually than when mixed with food. The benefits of dietary polyphenols for type 2 diabetes can be summarized as: protection of pancreatic β-cells against glucose toxicity, anti-inflammatory and antioxidant effects, inhibition of α-amylases or α- glucosidases and thus decrease of starch digestion, and inhibition of advanced glycation end products formation. Moreover, type 2 diabetes also significantly influences the benefits of dietary polyphenols, although there are very limited studies have been conducted so far. How type 2 diabetes impacts the pharmacology of dietary polyphenols is not well understood. Comprehension of type 2 diabetes-mediated changes in pharmacokinetics and bioactivity of dietary polyphenols might lead to improve the benefits of these phytochemicals and subsequent clinical outcomes for type 2 diabetics.

Cytotoxicity of Marchantia convoluta leaf extracts to human liver and lung cancer cells

The cytotoxicity of three extracts (petroleum ether, ethyl acetate and n-butanol) from a plant used in folk medicine, Marchantia convoluta, to human non-small cell lung carcinoma (H1299) and liver carcinoma (HepG2) cell lines was tested. After 72-h incubation of lung and liver cancer cell cultures with varying concentrations of extracts (15 to 200 microg/mL), cytotoxicity was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and reported in terms of cell viability. The extracts that showed a significant cytotoxicity were subjected to gas chromatography-mass spectrometry analysis to identify the components. The ethyl acetate, but not the petroleum ether or n-butanol extract, had a significant cytotoxicity against lung and liver carcinoma cells with IC50 values of 100 and 30 microg/mL, respectively. A high concentration of ethyl acetate extract (100 microg/mL) rapidly reduced the number of H1299 cells. At lower concentrations of ethyl acetate extract (15, 30, and 40 microg/mL), the numbers of HepG2 cells started to decrease markedly. Gas chromatography-mass spectrometry analysis of the ethyl acetate extract revealed the presence of several compounds such as phytol (23.42%), 1,2,4-tripropylbenzene (13.09%), 9-cedranone (12.75%), ledene oxide (7.22%), caryophyllene (1.82%), and caryophyllene oxide (1.15%). HPLC analysis result showed that there were no flavonoids in ethyl acetate extract, but flavonoids are abundant in n-butanol extract. Further studies are needed regarding the identification, toxicity, and mechanism of action of active compounds.