DMPK

Ethnopharmacological relevance: A wealth of information is emerging about the impact of gut microbiota on human health and diseases such as cardiovascular diseases, obesity and diabetes. As we learn more, we find out the gut microbiota has the potential as new territory for drug targeting. Some novel therapeutic approaches could be developed through reshaping the commensal microbial structure using combinations of different agents. The gut microbiota also affects drug metabolism, directly and indirectly, particularly towards the orally administered drugs. Herbal products have become the basis of traditional medicines such as traditional Chinese medicine and also been being considered valuable materials in modern drug discovery. Of note, low oral bioavailability but high bioactivity is a conundrum not yet solved for some herbs. Since most of herbal products are orally administered, the herbs' constituents are inevitably exposed to the intestinal microbiota and the interplays between herbal constituents and gut microbiota are expected. Emerging explorations of herb–microbiota interactions have an opportunity to revolutionize the way we view herbal therapeutics. The present review aims to provide information regarding the health promotion and/or disease prevention by the interplay between traditional herbs with low bioavailability and gut microbiota through gut microbiota via two different types of mechanisms: (1) influencing the composition of gut microbiota by herbs and (2) metabolic reactions of herbal constituents by gut microbiota. Materials and methods: The major data bases (PubMed and Web of Science) were searched using

The influence of some metallic therapeutic compounds on the pharmacokinetics of orally administered norfloxacin in healthy human volunteers has been examined. The in vitro availability of norfloxacin in dissolution media containing these metallic compounds was also studied. Peak saliva concentration (Cmax) and bioavailability (AUC0_9) of norfloxacin were reduced by approx. 35-fold, 3-5 fold and 40-50% when co-administered with ferrous sulphate, magnesium trisilicate and potassium citrate, respectively. Concomitant administration with sodium bicarbonate and aluminium hydroxide did not significantly modify the pharmacokinetics of norfloxacin but calcium carbonate reduced its bioavailability by 47%. The absorption and elimination rates of norfloxacin were not affected by the metallic compounds, except potassium citrate which decreased both the absorption and elimination of the drug. There was some degree of correlation between the saliva, urine and in vitro results. Based on the data obtained, it was evident that norfloxacin formed unabsorbable and/or antibacterially inactive/less active complexes with Fe 2+, Mg 2+ and AI 3+. Complex formation, adsorption and pH-mediated effects were proposed as factors responsible for the alteration of the pharmacokinetics of norfloxacin by the co-administered agents. There was no clearly discernible link between the valency of the metal ion and its influence on norfloxacin pharmacokinetics.