Effects of Monascus purpureus on ripe Pu-erh tea in different fermentation methods and identification of characteristic volatile compounds.

The present study aimed to explore the key volatile compounds (VCs) that lead to the formation of characteristic flavors in ripe Pu-erh tea (RIPT) fermented by Monascus purpureus (M. purpureus). Headspace solid-phase microextraction coupled with gas chromatography/mass spectrometry (HS-SPME-GC-MS), orthogonal partial least square-discriminant analysis (OPLS-DA) were employed for a comprehensive analysis of the VCs present in RIPT fermented via different methods and were further identified by odor activity value (OAV). The VCs 1,2-dimethoxybenzene, 1,2,3-trimethoxybenzene, (E)-linalool oxide (pyranoid), methyl salicylate, linalool, ß-ionone, ß-damascenone were the key characteristic VCs of RIPT fermented by M. purpureus. OAV and Gas chromatography-olfactometry (GC-O) further indicated that ß-damascenone was the highest contribution VCs to the characteristic flavor of RIPT fermented by M. purpureus. This study reveals the specificities and contributions of VCs present in RIPT under different fermentation methods, thus providing new insights into the influence of microorganisms on RIPT flavor.

Early prediction of body composition parameters on metabolically unhealthy in the Chinese population via advanced machine learning.

Background: Metabolic syndrome (Mets) is considered a global epidemic of the 21st century, predisposing to cardiometabolic diseases. This study aims to describe and compare the body composition profiles between metabolic healthy (MH) and metabolic unhealthy (MU) phenotype in normal and obesity population in China, and to explore the predictive ability of body composition indices to distinguish MU by generating machine learning algorithms. Methods: A cross-sectional study was conducted and the subjects who came to the hospital to receive a health examination were enrolled. Body composition was assessed using bioelectrical impedance analyser. A model generator with a gradient-boosting tree algorithm (LightGBM) combined with the SHapley Additive exPlanations method was adapted to train and interpret the model. Receiver-operating characteristic curves were used to analyze the predictive value. Results: We found the significant difference in body composition parameters between the metabolic healthy normal weight (MHNW), metabolic healthy obesity (MHO), metabolic unhealthy normal weight (MUNW) and metabolic unhealthy obesity (MUO) individuals, especially among the MHNW, MUNW and MUO phenotype. MHNW phenotype had significantly lower whole fat mass (FM), trunk FM and trunk free fat mass (FFM), and had significantly lower visceral fat areas compared to MUNW and MUO phenotype, respectively. The bioimpedance phase angle, waist-hip ratio (WHR) and free fat mass index (FFMI) were found to be remarkably lower in MHNW than in MUNW and MUO groups, and lower in MHO than in MUO group. For predictive analysis, the LightGBM-based model identified 32 status-predicting features for MUNW with MHNW group as the reference, MUO with MHO as the reference and MUO with MHNW as the reference, achieved high discriminative power, with area under the curve (AUC) values of 0.842 [0.658, 1.000] for MUNW vs. MHNW, 0.746 [0.599, 0.893] for MUO vs. MHO and 0.968 [0.968, 1.000] for MUO and MHNW, respectively. A 2-variable model was developed for more practical clinical applications. WHR > 0.92 and FFMI > 18.5 kg/m2 predict the increased risk of MU. Conclusion: Body composition measurement and validation of this model could be a valuable approach for the early management and prevention of MU, whether in obese or normal population.

A Nomogram Model for Predicting the Polyphenol Content of Pu-Erh Tea.

To investigate different contents of pu-erh tea polyphenol affected by abiotic stress, this research determined the contents of tea polyphenol in teas produced by Yuecheng, a Xishuangbanna-based tea producer in Yunnan Province. The study drew a preliminary conclusion that eight factors, namely, altitude, nickel, available cadmium, organic matter, N, P, K, and alkaline hydrolysis nitrogen, had a considerable influence on tea polyphenol content with a combined analysis of specific altitudes and soil composition. The nomogram model constructed with three variables, altitude, organic matter, and P, screened by LASSO regression showed that the AUC of the training group and the validation group were respectively 0.839 and 0.750, and calibration curves were consistent. A visualized prediction system for the content of pu-erh tea polyphenol based on the nomogram model was developed and its accuracy rate, supported by measured data, reached 80.95%. This research explored the change of tea polyphenol content under abiotic stress, laying a solid foundation for further predictions for and studies on the quality of pu-erh tea and providing some theoretical scientific basis.

MiR-92a regulates PTEN/Akt signaling axis to promote paclitaxel resistance in ovarian cancer cells.

To investigate the function and possible mechanism of miR-92a in malignant behaviors such as paclitaxel resistance in ovarian cancer (OC) cells. The miR-92a and PTEN expression were detected by real-time PCR (RT-PCR). The cell viability and apoptosis were detected by MTT, colony formation and flow cytometry assay, respectively. Dual-luciferase reporter assay was adopted to verify the targeting relationship between miR-92a and PTEN. Besides, we measured the relative protein levels of PTEN and p-AKT/AKT by Western blot. MiR-92a was significantly highly expressed in OC cells, and its high expression could notably enhance paclitaxel resistance, cell proliferation and colony formation, as well as inhibit apoptosis in SKOV3-Tax cells. Further luciferase reporter assay and expression detection showed that miR-92a could target and regulate PTEN and that there was a targeted relationship between them. In addition, further exploration of the mechanism revealed that miR-92a regulated PTEN/Akt signaling pathway. MiR-92a not only promotes the proliferation, colony formation and paclitaxel resistance of SKOV3-Tax cells in OC, but also inhibits apoptosis, and it may be related to the regulation of the PTEN/Akt signaling pathway. MiR-92a serves as a potential biomarker for the malignant biological behavior of OC cells.

Integrated genomics and transcriptomics reveal the extreme heavy metal tolerance and adsorption potentiality of Staphylococcus equorum.

In this study, we successfully isolated 11 species of cadmium-tolerant bacterium from Pu-erh rhizosphere soil, of which Staphylococcus equorum PU1 showed the highest cadmium tolerance, with a minimum inhibitory concentration (MIC) value of 500 mg/L. The cadmium removal efficiency of PU1 in 400 mg/L cadmium medium reached 58.7 %. Based on the Nanopore PromethION and Illumina NovaSeq platforms, we successfully obtained the complete PU1 genome with a size of 2,705,540 bp, which encoded 2729 genes. We further detected 82 and 44 indel mutations in the PU1 genome compared with the KS1039 and KM1031 genomes from the database. Transcriptional analysis showed that the expression of 11 genes in PU1 increased with increasing cadmium concentrations (from 0 to 200, then to 400 mg/L), which encoded cadmium resistance, cadmium transport, and mercury resistance genes. In addition, some genes showed differential expression patterns with changes in cadmium concentration, including quinone oxidoreductase-like protein, ferrous iron transport protein, and flavohemoprotein. Gene Ontology (GO) functions, including oxidation reduction process and oxidoreductase activity functions, and KEGG pathways, including glycolysis/gluconeogenesis and biosynthesis of secondary metals, were also considered closely related to the extreme cadmium tolerance of PU1. This study provides novel insight into the cadmium tolerance mechanism of bacteria.

Effects of Lightning on Rhizosphere Soil Properties, Bacterial Communities, and Active Components of Camellia sinensis var. assamica.

Lightning rods have been developed to prevent damage caused by lightning to organisms. However, the biological effect of the current transmitted into the soil through lightning rods is unknown. In this study, we analyzed the effects of lightning on soil properties, the microbial community, and the active components of Pu-erh tea (Camellia sinensis var. assamica) near lightning rods. The results showed that the contents of organic matter and available potassium, copper, and calcium in rhizosphere soil near the lightning rod were significantly higher than those in control soil (P < 0.05), while the contents of total potassium, phosphorus, iron, magnesium, and aluminum decreased. Lightning significantly increased the bacterial diversity of Pu-erh rhizosphere soil compared to control soil samples (P < 0.05). Sphingomonas, Nitrospira, and Reyranella were significantly enriched in soil samples near the lightning rod compared to soil samples far from the lightning rod. Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that adenosine/AMP kinase, chitodextrinase, flavorubredoxin, nucleotide metabolism, and carbohydrate digestion and absorption were significantly enriched in the rhizosphere soil samples near the lightning rod compared to the control samples (P < 0.05). ß diversity analysis indicated the grounding of the lightning rod contributed to the community differentiation of rhizosphere bacteria. Amino acids, polyphenols, and soluble sugar increased in Pu-erh tea near the lightning rod, while the contents of catechin and anthocyanin decreased in Pu-erh tea near the lightning rod compared with the control sample (P < 0.05). Significant correlations were found among microbial indicators, soil properties, and Pu 'er tea components. This study serves as the first report on the effects of lightning rods on soil properties, microecology, and plant metabolism, which promotes the understanding of the biological effects of lightning, and provides a reference for the rational use of lightning resources.

Evolution analysis of flavor-active compounds during artificial fermentation of Pu-erh tea.

For the urgent need for fermentation control and product quality improvement of Pu-erh tea, gas chromatography-mass spectrometry and odor activity value (OAV) were used to comprehensively investigate the flavor-active compounds during artificial fermentation of Pu-erh tea. A flavor wheel was constructed to expound the sensory attributes evolution during fermentation. With an increased total volatiles content, 43 were significantly up-regulated and 30 were down-regulated among 131 detected volatiles. Key active compounds of three aroma types, namely fresh fragrance, fruit-fungus fragrance and stale-Qu fragrance, were analyzed based on OAV. ß-damascenone was firstly found contributing most to the aroma of Pu-erh tea, followed by 1,2,3-methoxybenzene and (E,E)-2,4-nonadienal. γ-terpinene, linalool, 1,2,4-trimethoxybenzene, 1,2,3-trimethoxybenzene, and 4-ethylveratrol were identified as the potential markers responsible for aroma differences among three fermentation stages. Finally the metabolic evolution of key flavor-active compounds were systematically summarized. This study provides significant guidance in fermentation control and new product development of Pu-erh tea.

Hypolipidemic, anti-inflammatory, and anti-atherosclerotic effects of tea before and after microbial fermentation.

BACKGROUND: Microbial fermentation significantly affects the flavor and efficacy of tea. It is generally believed that fermented tea is more effective in lowering lipids, while unfermented tea can more effectively inhibit inflammation. However, there is not sufficient evidence to support this claim. To systematically compare the hypolipidemic, anti-inflammatory, and anti-atherosclerotic effects of tea before and after microbial fermentation, hyperlipidemic rats and inflammatory injury cells were treated with Monascus purpureus-fermented pu-erh tea water extract (MPT) and sun-dried green tea water extract (SGT), respectively. RESULTS: MPT, with higher levels of theabrownins, flavonoids, gallic acid (GA), and lovastatin, was more effective in reducing serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and inflammatory cytokines (TNF-α, IL-1ß, and IL-6), while SGT, with higher levels of tea polyphenols, amino acids, (-)-epigallocatechin gallate (EGCG), and theaflavins, was more effective in increasing serum high-density lipoprotein cholesterol (HDL-C) in hyperlipidemic rats. The foam cells on the arterial wall of the rats in the MPT group were visibly less, and the thrombosis time was longer than that in the SGT group. Cell experiments showed that MPT was more effective in protecting endothelial cells from damage than SGT. CONCLUSION: Surprisingly, Monascus purpureus-fermented pu-erh tea not only had better hypolipidemic and anti-atherosclerotic effects than its raw material (sun-dried green tea), but also was superior in anti-inflammatory effects to the latter, which was possibly attributable to the great changes in functional ingredients during microbial fermentation.

Anthocyanin Cyanidin-3-Glucoside Attenuates Platelet Granule Release in Mice Fed High-Fat Diets.

Platelet granule release is considered an important target for preventing and treating cardiovascular diseases (CVDs). Cyanidin-3-glucoside (Cy-3-g) is a predominant bioactive anthocyanin compound in many edible plants and has been reported to be protective against CVDs by attenuating platelet dysfunction. However, direct evidence of the action of Cy-3-g on platelet granule secretion in purified platelets from in vivo assays is still poor. In the present study, we demonstrated that dietary supplementation of purified Cy-3-g reduces serum lipid levels and facilitates down-regulation of the platelet granule release of substances such as P-selectin, CD40L, 5-HT, RANTES and TGF-ß1 in gel-filtered platelets, in addition to attenuating serum PF4 and ß-TG levels in mice fed high-fat diets. These results provide evidence that Cy-3-g protects against thrombosis and CVDs by inhibiting purified platelet granule release in vivo.

Synthesis of a highly active oxidation catalyst with improved distribution of titanium coordination states.

A facile strategy is proposed to construct a highly active oxidation catalyst with optimally distributed titanium coordination states containing "TiO4" and "TiO6" species. The "TiO6" species in TS-1(+) shows a superior catalytic oxidation activity, which is 2-3 times that of "TiO4" species in TS-1.

Plant food anthocyanins inhibit platelet granule secretion in hypercholesterolaemia: Involving the signalling pathway of PI3K-Akt.

Controlling platelet granule secretion has been considered an effective strategy to dampen thrombosis and prevent atherosclerosis. Anthocyanins are natural plant pigments and possess a wide range of biological activities, including cardiovascular protective activity. In the present study we explored the effects and the potential mechanisms of anthocyanins on platelet granule secretion in hypercholesterolemia. In a randomised, double-blind clinical trial, 150 hypercholesterolaemic individuals were treated with purified anthocyanins (320 mg/day) or placebo for 24 weeks. Anthocyanins consumption significantly reduced plasma levels of ß-thromboglobulin (ß-TG), soluble P-selectin, and of Regulated on Activation Normal T cell Expressed and Secreted (RANTES) as compared with the placebo. A minor reduction in platelet factor 4 (PF4) and transforming growth factor ß1 (TGF-ß1) levels were also observed. In in vitro experiments, we observed that puriÓ¿ed anthocyanin mixture, as well as its two main anthocyanin components, delphinidin-3-glucoside (Dp-3-g) and cyanidin-3-glucoside (Cy-3g) directly inhibited platelet á-granule, dense granule, and lysosome secretion evaluated by P-selectin, RANTES, ß-TG, PF4, TGF-ß1, serotonin, ATP, and CD63 release. Further, anthocyanins inhibited platelet PI3K/Akt activation and consequently attenuated eNOS phosphorylation and cGMP production, thus interrupting MAPK activation. LY294002, a PI3K inhibitor, did not cause additional inhibitory efficacy, indicating that anthocyanin-induced effects may be involved in inhibition of the PI3K/Akt signalling pathway. These results provide evidence that by inhibiting platelet granule secretion, anthocyanins may be a potent cardioprotective agent.

Enhanced catalytic activity of titanosilicates controlled by hydrogen-bonding interactions.

A typical volcano-shaped curve has been found in heterogeneous catalytic systems containing titanosilicates for the first time. A new reactive intermediate with double H-bonds is proposed. Systematic results clearly evidence another H-bond formed between the high-electronegativity atom of the H-bond acceptor and the H(end) atom of Ti-Oα-Oß-H(end).