Intelligent identification of picking periods of Lu'an Guapian tea by an indicator displacement colorimetric sensor array combined with machine learning.

Lu'an Gua Pian (LAGP) tea is one of the most famous green teas in China. The quality of green tea is related to its picking periods, especially the green tea before Qingming Festival (usually April 6th) is highly praised as precious in the market. In this work, a simple and cheap indicator displacement colorimetric sensor array combined with smartphone was developed to rapidly identify LAGP picked during different picking periods. First, the chemical component contents of LAGP picked before and after Qingming Festival were analyzed. Second, a well-designed colorimetric sensor array was proposed based on the tea component contents differences. Finally, machine learning was used to process the array data taken by a smartphone. By comparison, the accuracy of the best model for the prediction set was 97%. Meanwhile, the multi-channel advantages of the sensing array were demonstrated by an ablation experiment. In addition, the method achieved an AGREE analysis score of 0.88, indicating that it was environmental-friendly.

Inhibition of matrix metalloproteinase-9 expression by docosahexaenoic acid mediated by heme oxygenase 1 in 12-O-tetradecanoylphorbol-13-acetate-induced MCF-7 human breast cancer cells.

Matrix metalloproteinase-9 (MMP-9) plays a crucial role in tumor metastasis. Previous studies showed that polyunsaturated fatty acids exhibit an anti-cancer effect in various human carcinoma cells, but the effect of docosahexaenoic acid (DHA) and linoleic acid (LA) on metastasis of breast cancer cells is not fully clarified. We studied the anti-metastasis potential of DHA and LA in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced MCF-7 cells. We found that TPA (100 ng/ml) induced MMP-9 enzyme activity both dose- and time-dependently, and 200 µM DHA and LA significantly inhibited MMP-9 mRNA and protein expression, enzyme activity, cell migration, and invasion. Treatment with PD98059 (10 µM), wortmannin (10 µM), and GF109203X (0.5 µM) decreased TPA-induced MMP-9 protein expression and enzyme activity. TPA-induced activation of ERK1, Akt, and PKCδ was attenuated by DHA, whereas LA attenuated only ERK1 activation. GF109203X also suppressed ERK1 activation. EMSA showed that DHA, LA, PD98059, and wortmannin decreased TPA-induced NF-κB and AP-1 DNA-binding activity. Furthermore, DHA rather than LA dose-dependently increased HO-1 expression. HO-1 siRNA alleviated the inhibition by DHA of TPA-induced MMP-9 protein expression and enzyme activity in MCF-7 cells, and HO-1 knockdown reversed the DHA inhibition of cell migration. These results suggest that DHA and LA have both similar and divergent signaling pathways in the suppression of TPA-induced MCF-7 metastasis.

[Recent progresses in studies on bioactive lignans from plants].

Lignans are widely existed in natural world with a variety of structures and bioactivities, including anti-tumor, antiinflammatory, anti-viral and hepatoprotective properties. Along with the development of new techniques in phytochemistry and application of advanced drug screening methods, a variety of lignans have been identified and their bioactivities revealed. In this review, we summarized the activities of six different types of lignans, including arylnaphthalene, dibenzylbutyrolactone, tetrahydrofuran, dibenzylbutane, dibenzocyclooctadiene and neolignan, in order to provide an updated overview of this research field.

Vasorelaxant effect of euxanthone in the rat thoracic aorta.

This study was undertaken to investigate the effect of euxanthone on isolated rat thoracic aorta. Euxanthone concentration-dependently relaxed high K+-induced sustained contractions with IC50 values of 32.28+/-1.73 microM and this inhibition was antagonized by increasing the Ca2+ concentration in the medium. These results indicated that euxanthone may have calcium antagonistic property. Euxanthone also relaxed norepinephrine (NE)-induced sustained contractions with IC50 values of 32.50+/-2.15 microM and this relaxant effect was unaffected by the removal of endothelium or by the presence of propranolol, indomethacin, glibenclamide or N(omega)-nitro-L-arginine. Moreover, euxanthone inhibited both the phasic and tonic contractions induced by NE in a concentration-dependent manner and showed more potent inhibition on phasic contraction (P < 0.01). Pre-treatment with euxanthone inhibited vascular contraction induced by phorbol 12, 13-dibutyrate (PDBu), a protein kinase C (PKC) agonist, in either the presence or absence of Ca2+ in the solution with IC50 values of 20.15+/-1.56 and 18.30+/-1.62 microM, respectively. However, when the tissues were treated with euxanthone after the PDBu-induced contraction had reached a steady state, the tension was not affected by euxanthone. This study also showed that the inhibitory effect of pre-treatment of euxanthone was more potent than the post-treatment after the tension had reached a steady state. These results suggested that the vasorelaxation of euxanthone may be through multiple pathways involved PKC-mediated signal pathway and calcium-independent pathway besides the direct inhibition of calcium influx and its vasorelaxant effect is more active on calcium-independent pathway and more sensitive to the initial stage of contraction.

[Chemical constituents in roots of Polygala fallax and their anti-oxidation activities in vitro].

OBJECTIVE: To study the chemical constituents in roots of P. fallax and their anti-oxidation activities in vitro. METHOD: Column chromatographic techniques were employed for isolation and purification of chemical constituents of the plant. The structures were elucidated on the basis of the spectral evidence and the physical and chemical character. The isolated compounds were screened with four anti-oxidation models in vitro. RESULT: Seven xanthones, 1,7-dihydroxy-2,3-methylenedioxyxanthone (1), 1-methoxy-2,3-methylenedioxyxanthone (2), 3-hydroxy-1,2-dimethoxyxanthone (3), 1,6,7-trihydroxy-2,3-dimethoxyxanthone (4), 7-hydroxy-1-methoxy-2,3-methylenedioxyxanthone (5), 1,3-dihydroxy-2-methoxyxanthone (6) and 1,3,7-trihydroxy-2-methoxyxanthone (7), were isolated from the roots of P. fallax. And compounds 1 - 7 showed different anti-oxidation activities in the different pharmacological models. CONCLUSION: Compounds 2, 3, 5 and 7 were isolated from this plant for the first time. Xanthones from this plant showed anti-oxidation activities. The pharmacological activities of the pure compounds from this plant were also reported for the first time.

Distribution variations of multi allergens at asthmatic children's homes.

Increasing asthma prevalence is evident in many countries and childhood asthma has also become one of the most common chronic diseases in children. Exposure to indoor allergens has been be attributed to a significant increase in asthma occurrence. Meanwhile, allergen distribution varies widely among different countries. This brief investigation reports the distribution of common indoor allergens, such as mite (Dermatophagoides pteronyssinus, Der p 1 and Der p 2), cat (Felis domesticus, Fel d 1), and German cockroach allergens (Blattella germanica, Bla g 1) at different sites of asthmatic children in Taiwan. Approximately 40 asthmatic children's homes participated in this study and the cohort was followed prospectively for approximately 6 months, starting in December until the following May. Dust samples were collected from each child's mattress, and bedroom and living room floors. All samples were analyzed with monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA). Statistical difference of Der p 1 concen trations is observed among those on the mattress, bedroom and living room floor, except for in May. Seasonal variation in Der p 1 levels on the mattress and bedroom floor is also significant (P < 0.025 and 0.001, respectively). Distributional variation seems to be significant for most allergens among sites within homes in most seasons. Therefore, if only one sample is to be taken, the month of May would be a more ideal choice of study period, and detailed sampling across sites appears to be necessary should the true environmental exposure of allergens be desired.

Xanthones from the roots of Polygala caudata and their antioxidation and vasodilatation activities in vitro.

Three new xanthones, 2-hydroxy-1,6,7-trimethoxyxanthone (1), 1,4-dimethoxy-2,3-methylenedioxyxanthone (2), and 7-hydroxy-1,2-dimethoxyxanthone (3), together with five known compounds, 2,7-dihydroxy-1-methoxyxanthone (4), 1-methoxy-2,3-methylenedioxyxanthone (5), 7-hydroxy-1-methoxyxanthone (6), euxanthone (1,7-dihydroxyxanthone) (7), and gentitein (1,3,7-trihydroxyxanthone) (8), were isolated from the roots of Polygala caudata. Their structures were established on the basis of spectral evidence. In the antioxidation activity screening in vitro with luminol chemiluminescence methods, compounds 1 - 5 and 7 and 8 showed H2O2 scavenger activity, with a scavenging effect of 58.4 - 94.5% at 10 microg/mL, and 26.0 - 84.7% at 2 microg/mL. Compounds 4 and 8 also exhibited scavenging effects on the reactive oxygen free radicals produced by macrophage respiratory bursts, with a scavenging effect of 71.7% and 63.4% at 10 microg/mL, 41.2% and 47.8% at 2 microg/mL, respectively. In the vasodilatation assay, compounds 4 - 7 exhibited relaxing activity on the contractions evoked by KCl in Wistar rat thoracic aorta rings in a dose-dependent manner.