Association between caffeine consumption and bone mineral density in children and adolescent: Observational and Mendelian randomization study.

BACKGROUND: Coffee is the most commonly consumed beverage among children and adolescences. Caffeine was demonstrated to be associated with bone metabolism. However, the relationship between caffeine intake and BMD in children and adolescents remains unclear. This study aimed to identified relationship between caffeine consumption and bone mineral density (BMD) in children and adolescents. METHODS: Based on National Health and Nutrition Examination Survey (NHANES), we conducted an epidemiological cross-section study to measure the relationship between caffeine consumption and BMD in children and adolescents by multivariate linear regression models. Then, five methods of Mendelian randomization (MR) analyses were performed to estimate their causal relationship between coffee and caffeine intake and BMD in children and adolescents. MR-Egger and inverse-variance weighted (IVW) were used to evaluate the heterogeneity effect of instrumental variables (IVs). RESULTS: In epidemiological studies, individuals with the highest quartile of caffeine intake do not have a significant change in femur neck BMD (ß = 0.0016, 95% CI: -0.0096, 0.0129, P = 0.7747), total femur BMD (ß = 0.0019, P = 0.7552), and total spine BMD (ß = 0.0081, P = 0.1945) compared with the lowest quartile. In MR analysis, the IVW-random effect indicates no causal relationship between coffee consumption and TB- BMD (ß = 0.0034, P = 0.0910). Other methods of MR analyses and sensitivity analysis reveals consistent findings. Similarly, the fixed-effects IVW method shows no causal association between caffeine intake and TB-BMD in children and adolescents (ß = 0.0202, P = 0.7828). CONCLUSIONS: Our study does not support a causal relationship between caffeine consumption and BMD in children and adolescents. However, more studies are needed to verify our findings, such as its underlying molecular mechanisms and the long-term impact of early caffeine exposure at a younger age.

Mechanism of Wuyao-Ginseng Medicine Pair in the Prevention and Treatment of Diarrhea-Type Irritable Bowel Syndrome Based on Gene Expression Omnibus Chip Data.

Based on a Gene Expression Omnibus (GEO) chip analysis combined with network pharmacology and molecular docking technology, in this study we explored the molecular targets and mechanism of the wuyao-ginseng medicine pair in the prevention and treatment of diarrhea-type irritable bowel syndrome (IBS-D). The Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) was used to search for the chemical constituents and targets of wuyao and ginseng. The UniProt database was used to search for the target gene name. In the GEO database, IBS was searched to obtain GSE36701 and GSE14841 microarray data. We imported the intersection targets into the STRING database to construct a protein-protein interaction (PPI) network. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (Go) pathway analyses were performed using the Metascape database. A total of 30 active ingredients of wuyao-ginseng, 171 drug targets, 1257 IBS differentially expressed genes, and 20 drug-disease intersection genes were obtained from the GEO data. We screened the results and obtained the core active ingredients beta-sitosterol, DMPEC, Boldine, etc.; the core targets NCOA2, EGFR, VEGFA, etc.; and the key pathways P13K-Akt, MAPK, etc. The wuyao-ginseng medicine pair may be involved in inflammation-related signaling pathways, acting on disease targets such as NCOA2, EGFR, and VEGFA as well as pathways such as P13K-Akt and MAPK, thereby playing a key role in the prevention and treatment of IBS-D.

[Effect of phosphorus stress on chlorophyll biosynthesis, photosynthesis and biomass partitioning pattern of Fraxinus mandchurica seedlings].

Phosphorus is essential to forest trees for their growth and development, because of its important role in many metabolic processes of trees. But, most part of phosphorus in soils of Northeastern China is immobile and unavailable, and thus, many forest trees often suffer from phosphorus stress which affects the biomass accumulation of forest trees. The aim of this study is to understand how the chlorophyll biosynthesis, photosynthesis and biomass partitioning of Fraxinus mandchurica seedlings response to phosphorus stress. Sand culture experiment showed that when the seedlings were under phosphorus stress, their 5-aminolevulinic acid (ALA) biosynthesis rate and porphobilinogen (PBG) synthase activity were reduced, but no significant changes in chlorophyll a and b, total chlorophyll and carotenoid contents were found. The nitrogen content in leaves and roots and the phosphorus content in all parts of seedlings were reduced under phosphorus stress, and the reduction of N content in leaves induced the decrease of maximum quantum efficiency of PS II (Fv/Fm) efficiency of PS II photochemistry (phi(PS II)), electron transport rate (E(TR)), and maximum photosynthesis rate (Amax). The effect of phosphorus stress on chlorophyll biosynthesis didn't affect photosynthesis. Under phosphorus stress, the total biomass decreased, but more biomass was partitioned into roots.