Characterization of hyperglycemia due to sub-chronic administration of red ginseng extract via comparative global proteomic analysis.

Ginseng (Panax ginseng Meyer) is commonly used as an herbal remedy worldwide. Few studies have explored the possible physiological changes in the liver although patients often self-medicate with ginseng preparations, which may lead to exceeding the recommended dose for long-term administration. Here, we analyzed changes in the hepatic proteins of mouse livers using quantitative proteomics after sub-chronic administration of Korean red ginseng (KRG) extract (control group and 0.5, 1.0, and 2.0 g/kg KRG) using tandem mass tag (TMT) 6-plex technology. The 1.0 and 2.0 g/kg KRG groups exhibited signs of liver injury, including increased levels of aspartate transaminase (AST) and alanine aminotransferase (ALT) in the serum. Furthermore, serum glucose levels were significantly higher following KRG administration compared with the control group. Based on the upregulated proteins found in the proteomic analysis, we found that increased cystathionine beta-synthase (CBS) and cystathionine gamma-lyase (CSE) levels promoted greater hydrogen sulfide (H2S) synthesis in the liver. This investigation provides novel evidence that sub-chronic administration of KRG can elevate H2S production by increasing protein expression of CBS and CSE in the liver.

Characterization of red ginseng-drug interaction by CYP3A activity increased in high dose administration in mice.

Ginseng (Panax ginseng Meyer) is a popular traditional herbal medicine used worldwide. Patients often take ginseng preparations with other medicines where the ginseng dose could exceed the recommended dose during long-term administration. However, ginseng-drug interactions at high doses of ginseng are poorly understood. This study showed the possibility of herb-drug interactions between the Korean red ginseng (KRG) extract and cytochrome P450 (CYP) substrates in higher administration in mice. The CYP activities were determined in vivo after oral administration of KRG extract doses of 0.5, 1.0, and 2.0 g/kg for 2 or 4 weeks by monitoring the concentration of five CYP substrates/metabolites in the blood. The area under the curve for OH-midazolam/midazolam catalysed by CYP3A was increased significantly by the administration of 2.0 g/kg KRG extract for 2 and 4 weeks. CYP3A-catalysed midazolam 1'-hydroxylation also increased significantly in a dose- and time-dependent manner in the S9 fraction of mouse liver which was not related to induction by transcription. Whereas CYP2D-catalysed dextromethorphan O-deethylation decreased in a dose- and time-dependent manner in vivo. In conclusion, interactions were observed between KRG extract and CYP2D and CYP3A substrates at subchronic-high doses of KRG administration in mice.

Characterization of osthenol metabolism in vivo and its pharmacokinetics.

Osthenol, a prenylated coumarin, is a C8-prenylated derivative of umbelliferone isolated from the root of Angelica koreana and Angelica dahurica, an intermediate and is known as a major metabolite of desmethyl-osthole.The various pharmacological effects of osthenol have been reported. In previous studies, we investigated five hydroxylated metabolites by cytochromes P450 (CYP) and glucuronide conjugates of osthenol by uridine diphosphate-glucuronosyltransferases (UGTs). However, osthenol have very few studies have been reported on its pharmacokinetic (PK) profiling, we reported the PK parameters in mouse of osthenol through this study.After oral (5 and 20 mg/kg) and intravenous (5 mg/kg) administration, the concentration of osthenol in plasma was determined by LC-MS/MS. The quantitative method was validated in terms of linearity, accuracy, and precision. When 5 and 20 mg/kg of osthenol were orally administered, the bioavailability (BA) was found to be very low at 0.43 and 0.02%, respectively.In fact, osthenol was mostly metabolized to a two-Phase II conjugates, a sulfonyl and glucuronyl-osthenol, in the blood, which was determined by LC-HR/MS analysis of the blood sample. Because osthenol is rapidly metabolized to two conjugates by first-pass effect the BA of osthenol is low after oral administration.

Assessing Drug Interaction and Pharmacokinetics of Loxoprofen in Mice Treated with CYP3A Modulators.

Loxoprofen (LOX) is a non-selective cyclooxygenase inhibitor that is widely used for the treatment of pain and inflammation caused by chronic and transitory conditions. Its alcoholic metabolites are formed by carbonyl reductase (CR) and they consist of trans-LOX, which is active, and cis-LOX, which is inactive. In addition, LOX can also be converted into an inactive hydroxylated metabolite (OH-LOXs) by cytochrome P450 (CYP). In a previous study, we reported that CYP3A4 is primarily responsible for the formation of OH-LOX in human liver microsomes. Although metabolism by CYP3A4 does not produce active metabolites, it can affect the conversion of LOX into trans-/cis-LOX, since CYP3A4 activity modulates the substrate LOX concentration. Although the pharmacokinetics (PK) and metabolism of LOX have been well defined, its CYP-related interactions have not been fully characterized. Therefore, we investigated the metabolism of LOX after pretreatment with dexamethasone (DEX) and ketoconazole (KTC), which induce and inhibit the activities of CYP3A, respectively. We monitored their effects on the PK parameters of LOX, cis-LOX, and trans-LOX in mice, and demonstrated that their PK parameters significantly changed in the presence of DEX or KTC pretreatment. Specifically, DEX significantly decreased the concentration of the LOX active metabolite formed by CR, which corresponded to an increased concentration of OH-LOX formed by CYP3A4. The opposite result occurred with KTC (a CYP3A inhibitor) pretreatment. Thus, we conclude that concomitant use of LOX with CYP3A modulators may lead to drug-drug interactions and result in minor to severe toxicity even though there is no direct change in the metabolic pathway that forms the LOX active metabolite.

Identification of sulfonyl-loxoprofen as novel phase 2 conjugate in rat.

Loxoprofen is a prodrug that exerts strong analgesic and anti-inflammatory effects through its active trans-alcohol metabolite, which is produced in the liver by carbonyl reductase. Previous metabolic studies have evaluated loxoprofen, but its sulfate and taurine conjugates have not yet been studied. We characterized the metabolomic profile of loxoprofen in rat plasma, urine, and feces using high-resolution mass spectrometry. We identified 17 metabolites of loxoprofen in the three different biological matrices, 13 of which were detected in plasma and feces and 16 in urine. Amongst these metabolites, two novel taurine conjugates (M12 and M13) and two novel acyl glucuronides (M14, M15) were identified for the first time in rats. In addition, we detected three novel sulfate conjugates (M9, M10, and M11) of loxoprofen. Further study of these metabolites of loxoprofen is essential in order to assess their potency and toxicity.