A comprehensive study of celastrol metabolism in vivo and in vitro using ultra-high-performance liquid chromatography coupled with hybrid triple quadrupole time-of-flight mass spectrometry.

Celastrol has attracted great attention owing to its anti-arthritis, antioxidant, and anticancer activities. Nevertheless, its metabolism in vivo (rats) and in vitro (rat liver microsomes and intestinal flora) has not been comprehensively characterized. In this study, ultra-high-performance liquid chromatography coupled with hybrid triple quadrupole time-of-flight mass spectrometry was used as a rapid and sensitive approach for studying the metabolism of celastrol in vivo and in vitro. A total of 43 metabolites were identified and characterized. These include 26 metabolites in vivo, and 28 metabolites in vitro (nine metabolites in rat liver microsomes and 24 metabolites in rat intestinal flora). Additionally, the celastrol-biotransformation capacity of the intestinal tract was confirmed to exceed that of the liver. Furthermore, the metabolic profile of celastrol is summarised. The information obtained from this study may provide a basis for understanding the pharmacological mechanisms of celastrol and will be beneficial for clinical applications.

Preparation, evaluation and metabolites study in rats of novel Isoginkgetin-loaded TPGS/soluplus mixed nanomicelles.

At present, cancer is one of the most lethal diseases in the world, and researchers are committed to developing effective anticancer drugs. Isoginkgetin (IGG) is a kind of biflavone with the potential to treat cancer due to the features of altering the cell cycle and inhibiting tumor cell infiltration. However, its solubility, absorbability and bioavailability are poor, so in this study, IGG was prepared into mixed nanomicelles and evaluated in vitro and in vivo. After condition optimization, IGG-loaded TPGS/soluplus mixed nanomicelles with particle size of 62.34 ± 1.10 nm, entrapment efficiency of 96.92 ± 0.66% and drug loading of 2.42 ± 0.02% were successfully prepared. The physicochemical properties of the nanomicelles were stable within 60 days, and the cytotoxicity of the nanomicelles was significantly higher than that of IGG. The metabolism results showed that 32 kinds of metabolites of IGG and 21 kinds of IGG-loaded nanomicelles were detected. The metabolites of IGG can only be detected in feces of rats, while the metabolites of IGG-loaded nanomicelles can be detected in plasma, bile, urine and feces. All these indicated that after prepared into nanomicelles, the stability, solubility, cytotoxicity and bioavailability of IGG were increased significantly, which provided a new choice for the development of new drugs.