Comparative Metabolism Study of Five Protoberberine Alkaloids in Liver Microsomes from Rat, Rhesus Monkey, and Human.

Protoberberine alkaloids including berberine, palmatine, jatrorrhizine, coptisine, and epiberberine are major components in many medicinal plants. They have been widely used for the treatment of cancer, inflammation, diabetes, depression, hypertension, and various infectious areas. However, the metabolism of five protoberberine alkaloids among different species has not been clarified previously. In order to elaborate on the in vitro metabolism of them, a comparative analysis of their metabolic profile in rat, rhesus monkey, and human liver microsomes was carried out using ultrahigh-performance liquid chromatography coupled with a high-resolution linear trap quadrupole-Orbitrap mass spectrometer (UHPLC-electrospray ionization-Orbitrap MS) for the first time. Each metabolite was identified and semiquantified by its accurate mass data and peak area. Fifteen metabolites were characterized based on accurate MS/MS spectra and the proposed MS/MS fragmentation pathways including demethylation, hydroxylation, and methyl reduction. Among them, the content of berberine metabolites in human liver microsomes was similar with those in rhesus monkey liver microsomes, whereas berberine in rat liver microsomes showed no demethylation metabolites and the content of metabolites showed significant differences with that in human liver microsomes. On the contrary, the metabolism of palmatine in rat liver microsomes resembled that in human liver microsomes. The content of jatrorrhizine metabolites presented obvious differences in all species. The HR-ESI-MS/MS fragmentation behavior of protoberberine alkaloids and their metabolic profile in rat, rhesus monkey, and human liver microsomes were investigated for the first time. The results demonstrated that the biotransformation characteristics of protoberberine alkaloids among different species had similarities as well differences that would be beneficial for us to better understand the pharmacological activities of protoberberine alkaloids.

Promiscuous Pathogenicity Islands and Phylogeny of Pathogenic Streptomyces spp.

Approximately 10 Streptomyces species cause disease on underground plant structures. The most economically important of these is potato scab, and the most studied of these pathogens is Streptomyces scabiei (syn. S. scabies). The main pathogenicity determinant of scab-causing Streptomyces species is a nitrated diketopiperazine, known as thaxtomin A (ThxA). In the pathogenic species Streptomyces turgidiscabies, ThxA biosynthetic genes reside on a mobile pathogenicity island (PAI). However, the mobilization of PAIs in other Streptomyces species remains uncharacterized. Here, we investigated the mobilization of the PAI of S. scabiei 87-22. Based on whole genome sequences, we inferred the evolutionary relationships of pathogenic Streptomyces species and discovered that Streptomyces sp. strain 96-12, a novel pathogenic species isolated from potatoes in Egypt, was phylogenetically grouped with nonpathogenic species rather than with known pathogenic species. We also found that Streptomyces sp. strain 96-12 contains a PAI that is almost identical to the PAI in S. scabiei 87-22, despite significant differences in their genome sequences. This suggested direct or indirect in vivo mobilization of the PAI between S. scabiei and nonpathogenic Streptomyces species. To test whether the S. scabiei 87-22 PAI could, indeed, be mobilized, S. scabiei 87-22 deletion mutants containing antibiotic resistance markers in the PAI were mated with Streptomyces diastatochromogenes, a nonpathogenic species. The PAI of S. scabiei was site-specifically inserted into the aviX1 gene of S. diastatochromogenes and conferred pathogenicity in radish seedling assays. Our results demonstrated that S. scabiei, the earliest described Streptomyces pathogen, could be the source of a PAI responsible for the emergence of novel pathogenic species.

Pharmacokinetic-Pharmacodynamic Analysis on Inflammation Rat Model after Oral Administration of Huang Lian Jie Du Decoction.

Huang-Lian-Jie-Du Decoction (HLJDD) is a classical Traditional Chinese Medicine (TCM) formula with heat-dissipating and detoxifying effects. It is used to treat inflammation-associated diseases. However, no systematic pharmacokinetic (PK) and pharmacodynamic (PD) data concerning the activity of HLJDD under inflammatory conditions is available to date. In the present study, the concentration-time profiles and the hepatic clearance rates (HCR) of 41 major components in rat plasma in response to the oral administration of a clinical dose of HLJDD were investigated by LC-QqQ-MS using a dynamic multiple reaction monitoring (DMRM) method. Additionally, the levels of 7 cytokines (CKs) in the plasma and the body temperature of rats were analyzed. Furthermore, a PK-PD model was established to describe the time course of the hemodynamic and anti-inflammatory effects of HLJDD. As one of the three major active constituents in HLJDD, iridoids were absorbed and eliminated more easily and quickly than alkaloids and flavonoids. Compared with the normal controls, the flavonoids, alkaloids and iridoids in inflamed rats exhibited consistently changing trends of PK behaviors, such as higher bioavailability, slower elimination, delays in reaching the maximum concentration (Tmax) and longer substantivity. The HCR of iridoids was different from that of alkaloids and flavonoids in inflamed rats. Furthermore, excellent pharmacodynamic effects of HLJDD were observed in inflamed rats. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1ß, IL-10, and macrophage inflammatory protein-2 (MIP-2) and body temperature significantly decreased after the administration of HLJDD. Based on PK-PD modeling with the three-phase synchronous characterization of time-concentration-effect, flavonoids exhibited one mechanism of action in the anti-inflammatory process, while iridoids and alkaloids showed another mechanism of action. Taken together, the results demonstrated that HLJDD may restrain inflammation synergistically via its major constituents (alkaloids, flavonoids and iridoids). A correlation between the exposure concentration of different types of compounds and their anti-inflammatory effects in the body was shown. This study provides a comprehensive understanding of the anti-inflammatory activity of HLJDD.

Metabolic fate analysis of Huang-Lian-Jie-Du Decoction in rat urine and feces by LC-IT-MS combining with LC-FT-ICR-MS: a feasible strategy for the metabolism study of Chinese medical formula.

1. Huang-Lian-Jie-Du Decoction (HLJDD) is widely used for the treatment of hypertension, diabetes, inflammation and neural system diseases in clinic. In the present study, the comprehensive metabolic profile of HLJDD was demonstrated reliably and rapidly followed by the metabolic pathway analysis of six typical pure compounds (four alkaloids, one flavonoid and one iridoid) in HLJDD using LC-IT-MS combined with high resolution LC-FT-ICR-MS. 2. Totally, 85 compounds, including 32 prototype components and 53 biotransformed metabolites were detected and characterized in the urine and feces after oral administration of HLJDD and six pure compounds to rats, respectively. Among them, 17 prototypes were identified definitely with standard references. 3. Hydroxylation, demethylation and glucuronidation reactions of alkaloids, as well as glucuronidation and sulfonation reactions of iridoids and flavonoids, were observed as the major metabolic pathways of HLJDD. Flavonoids, iridoids and their metabolites were mainly excreted from urine. However, amount of alkaloids were detected in feces. 4. In general, the distinctive metabolic process of three kinds of representative components in HLJDD was clarified. The in vivo metabolic network of HLJDD was demonstrated. Meanwhile, the investigation of representative pure compounds in metabolic study provided a valuable strategy to elucidate the full-scale metabolic fate of HLJDD. This might be helpful to understand the in vivo mechanism of Traditional Chinese medicine (TCM).

[LC-FT-ICR-MS analysis of the prototypes and metabolites in rat plasma after administration of huang-lian-jie-du decoction].

To obtain chemical constituent information of rat plasma after oral administration of Huang-Lian-Jie-Du Decoction (HLJDD), a LC-FT-ICR-MS method has been established, and both positive and negative ions scan modes were include in the analysis. By comparing their retention time, high resolution mass data of HLJDD extracts, blank plasma and dosed plasma, 38 constituents, including 22 prototype compounds and 16 metabolites, were detected in rat plasma after oral administration of HLJDD. In the 22 prototype compounds, 16 constituents were determined unambiguously by comparing with references. In the analysis of metabolites, phase II reactions like glucuronidation and sulfation were the major biotransformation pathways of HLJDD. M11 was observed as the only phase I metabolite in present experiment. The results will be beneficial for the further pharmacokinetics and pharmacological evaluations of HLJDD.