3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:1518-1528.

Sulfur doped in carbon matrix can tether metal atoms to form high-loading atomically dispersed supported metal catalysts.

ABSTRACT:Cardiotonic pills are a type of cardiovascular herbal medicine. To identify suitable pharmacokinetic (PK) marker(s) for indicating systemic exposure to cardiotonic pills, we examined the in vivo PK properties of putatively active phenolic acids from the component herb Danshen (Radix Salviae miltiorrhizae). We also performed in vitro and in silico assessments of permeability and solubility. Several phenolic acids were investigated, including tanshinol (TSL); protocatechuic aldehyde (PCA); salvianolic acids A, B, and D; rosmarinic acid; and lithospermic acid. Plasma TSL exhibited the appropriate PK properties in dogs, including dose-dependent systemic exposure in area under concentration-time curve (AUC) and a 0.5-h elimination half-life. In rats, more than 60% of i.v. TSL was excreted intact into the urine. In humans, we found a significant correlation between the urinary recovery of TSL and its plasma AUC. The absorption rate and bioavailability of TSL were not significantly different whether cardiotonic pills were given p.o. or sublingually. The gender specificity in plasma AUC disappeared after body-weight normalization, but the renal excretion of TSL was significantly greater in women than in men. PCA was predicted to be highly permeable according to in vitro and in silico studies; however, extensive presystemic hepatic elimination and degradation in the erythrocytes led to extremely low plasma levels and poor dose proportionality. Integrated in vivo, in vitro, and in silico studies on the other phenolic acids showed poor gut permeability and nearly undetectable levels in plasma and urine. In conclusion, plasma and urinary TSL are promising PK markers for cardiotonic pills at the tested dose levels.The use of herbal therapies is escalating worldwide. However, the basis for the therapeutic effects is often poorly interpreted, and the safety, dose, and potential herb-drug interactions require better estimation (Fugh-Berman, 2000;De Smet, 2002;Lazar, 2004). Unlike most synthetic drugs, herbal medicinal products usually contain numerous chemical constituents, especially traditional Chinese medicines that often use a combination of multiple herbs.Determining which constituents of an herbal product have favorable drug-like properties will extend our knowledge of the basis for pharmacological efficacy and safety. An herbal constituent can be defined as drug-like when it possesses the desired potency, a wide safety margin, and appropriate pharmacokinetic (PK) properties and exists in adequate abundance in the herbal product. A deficit in these properties limits the usefulness of the herbal constituent for the herbal product. For a drug, the pharmacologic effect is attained when the drug or its active metabolite reaches and sustains an adequate concentration at an appropriate site of action; this hypothesis should also be applied to the herbal product. Both the dose levels and fates of active constituents in the body govern their target-site concentrations after administration of an herbal product. The releva...

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