Dendrobium officinale polysaccharides

Dendrobium officinale polysaccharide (DOP) is widely recognized for its excellent pharmacological activities, however, the in-depth pharmacokinetic characteristic remains unrevealed, significantly hindering its further development. It was hypothesized that Bacteroides predominantly mediates the in vivo metabolism of DOP via polysaccharide utilization loci (PULs), and the resulting oligosaccharides can be directly absorbed by the intestine. To verify this hypothesis, metagenomic sequencing analysis was first employed, confirming that DOP stimulates an upregulation of PULs associated with carbohydrate metabolism within the gut microbiota dominated by Bacteroides. The metabolized oligosaccharides were correlated with highly expressed endo-β-1,4-mannanase from Bacteroides. Further utilizing fluorescent labeling techniques, it was demonstrated that oligosaccharides derived from DOP metabolism are directly absorbed by intestinal tissues. Unabsorbed metabolites subsequently undergo disordered metabolism by gut microbiota into small molecules such as short-chain fatty acids. Collectively, these findings provide novel evidence for elucidating the pharmacological activities of DOP and offer new insights into pharmacokinetic research for other polysaccharides.

Phthalate esters (PAEs), widely employed as plasticizers, have garnered significant attention due to their multiple entry pathways into the environment, posing substantial threats to ecosystems. While current reviews predominantly focus on acute or high-dose toxicity in isolated environments or organisms, the present review addresses the critical knowledge gap. The present review encompasses peer-reviewed studies listed in the Web of Science from January 2017 to December 2024, excluding repetitive, irrelevant studies and those with invalid or incomplete data. Six common PAEs (BBP: butyl benzyl phthalate; DBP: di-n-butyl phthalate; DEHP: di(2-ethylhexyl) phthalate; DEP: diethyl phthalate; DMP: dimethyl phthalate; DOP: di-n-octyl phthalate) were listed as priority control contaminants by the US EPA. We comprehensively examine the environmental distribution and ecotoxicological impacts of these six PAEs. The toxicity differences among six PAEs were evaluated by integrating several indicators, such as oxidative stress, developmental disruption, endocrine dysfunction, metabolic alterations, reproductive impairment, and neurotoxicity. The mixture interactions were also examined because environmental exposure typically involves multiple PAEs and co-contaminants rather than single compounds. The PAE concentrations range from 0.00220 to 25.1 mg kg^-1 and vary significantly with geographic location and soil cultivation type. Both aquatic organisms (e.g., fish and invertebrates) and soil organisms (e.g., earthworms and nematodes) exhibit pronounced toxic responses to various PAEs. The combined toxicity of PAEs with other environmental contaminants revealed synergistic/antagonistic effects-a critical consideration that is frequently overlooked in ecological risk assessments. The evidence presented provides a robust scientific foundation for updating current PAE regulations to address real-world exposure scenarios involving complex mixtures and long-term effects.