Systematically identifying the hepatoprotective ingredients of schisandra lignan extract from pharmacokinetic and pharmacodynamic perspectives.

BACKGROUND: Herbal medicines (HMs) have been proven to be productive sources of leads for the development of drugs. To date approximately 150 lignans have been identified from Schisandra sphenanthera. Hepatoprotective activity is a well-known characteristic of schisandra lignans, yet the authentic types of active lignans are still not well known. PURPOSE: The present study aimed to develop a reliable and efficient strategy for identifying the hepatoprotective ingredients of schisandra lignan extract (SLE). METHODS: SLEs were prepared by extracting Schisandra sphenanthera powder using 10%, 50% and 90% ethanol (w/w 1:10) combining 5-fold volume of ethyl acetate. The schisandra lignans in SLEs were qualitatively analyzed based on liquid chromatography hybrid ion trap time-of-flight mass spectrometry (LCMS-IT-TOF). Preparative liquid chromatography (PLC) was used to collect ingredient fractions. The hepatoprotective activity of schisandra lignans was systematically investigated on in vivo and in vitro models. RESULTS: The SLE extracted by 50% ethanol and 5-fold volume of ethyl acetate (50%SLE) had the highest lignan content and exhibited significantly stronger hepatoprotective activity than other SLEs (P <  0.01). The hepatoprotective effect of 50%SLE mainly attributed to the SLE segment which collected from 12 to 22 min by PLC. Schisantherin A (Sth A) was confirmed as the most promising hepatoprotective drug in Schisandra sphenanthera due to high content in crude materials, high exposure level in vivo and high efficiency on APAP-induced hepatotoxicity. CONCLUSION: The hepatoprotective ingredients of SLEs were systematically investigated based on the presently developed approach, and Sth A was identified as the optimum hepatoprotective candidate in Schisandra sphenanthera.

Low Cerebral Exposure Cannot Hinder the Neuroprotective Effects of Panax Notoginsenosides.

A bidirectional route of communication between the gastrointestinal tract and the central nervous system, termed the "gut-brain axis," is becoming increasingly relevant to treatment of cerebral damage. Panax Notoginsenoside extract (PNE) is popular for prevention and treatment of cardio-cerebrovascular ischemic diseases although plasma and cerebral exposure levels are extremely low. To date, the mechanisms underlying the neuroprotective effects of PNE remain largely unknown. In the present study, the neuroprotective effects of PNE were systematically studied via investigation of the regulation by PNE of the gastrointestinal microbial community and γ aminobutyric acid (GABA) receptors. The results demonstrated that pretreatment with PNE exerted a remarkable neuroprotective effect on focal cerebral ischemia/reperfusion (I/R) injury in rats, and the efficiency was attenuated in germ-free rats. Pretreatment with PNE could significantly prevent downregulation of Bifidobacterium longum (B.L) caused by I/R surgery, and colonization by B.L could also exert neuroprotective effects. More importantly, both PNE and B.L could upregulate the expression of GABA receptors in the hippocampus of I/R rats, and coadministration of a GABA-B receptor antagonist could significantly attenuate the neuroprotective effects of PNE and B.L. The study above suggests that the neuroprotective effects of PNE may be largely attributable to its regulation of intestinal flora, and oral treatment with B.L was also useful in therapy of ischemia/reperfusion injury (I/R) by upregulating GABA-B receptors.

Qualitatively and quantitatively investigating the regulation of intestinal microbiota on the metabolism of panax notoginseng saponins.

ETHNOPHARMACOLOGICAL RELEVANCE: Intestinal microflora plays crucial roles in modulating pharmacokinetic characteristics and pharmacological actions of active ingredients in traditional Chinese medicines (TCMs). However, the exact impact of altered intestinal microflora affecting the biotransformation of TCMs remains poorly understood. AIMS OF THE STUDY: This study aimed to reveal the specific enterobacteria which dominate the metabolism of panax notoginseng saponins (PNSs) via exploring the relationship between bacterial community structures and the metabolic profiles of PNSs. MATERIALS AND METHODS: 2, 4, 6-Trinitrobenzenesulphonic acid (TNBS)-challenged and pseudo germ-free (pseudo GF) rats, which prepared by treating TNBS and antibiotic cocktail, respectively, were employed to investigate the influence of intestinal microflora on the PNS metabolic profiles. Firstly, the bacterial community structures of the conventional, TNBS-challenged and pseudo GF rat intestinal microflora were compared via 16S rDNA amplicon sequencing technique. Then, the biotransformation of protopanaxadiol-type PNSs (ginsenoside Rb1, Rb2 and Rd), protopanaxatriol-type PNSs (ginsenoside Re, Rf, Rg1 and notoginsenoside R1) and Panax notoginseng extract (PNE) in conventional, TNBS-challenged and pseudo GF rat intestinal microbiota was systematically studied from qualitative and quantitative angles based on LC-triple-TOF/MS system. Besides, glycosidases (ß-glucosidase and ß-xylosidase), predominant enzymes responsible for the deglycosylation of PNSs, were measured by the glycosidases assay kits. RESULTS: Significant differences in the bacterial community structure on phylum, class, order, family, and genera levels were observed among the conventional, TNBS-challenged and pseudo GF rats. Most of the metabolites in TNBS-challenged rat intestinal microflora were identified as the deglycosylation products, and had slightly lower exposure levels than those in the conventional rats. In the pseudo GF group, the peak area of metabolites formed by loss of glucose, xylose and rhamnose was significantly lower than that in the conventional group. Importantly, the exposure levels of the deglycosylated metabolites were found have a high correlation with the alteration of glycosidase activities and proteobacteria population. Several other metabolites, which formed by oxidation, dehydrogenation, demethylation, etc, had higher relative exposure in pseudo GF group, which implicated that the up-regulation of Bacteroidetes could enhance the activities of some redox enzymes in intestinal microbiota. CONCLUSION: The metabolism of PNSs was greatly influenced by intestinal microflora. Proteobacteria may affect the deglycosylated metabolism of PNSs via regulating the activities of glycosidases. Besides, up-regulation of Bacteroidetes was likely to promote the redox metabolism of PNSs via improving the activities of redox metabolic enzymes in intestinal microflora.

Development of a novel sectional multiple filtering scheme for rapid screening and classifying metabolites of ziyuglycoside II in rat liver and excreta specimen based on high-resolution mass spectrometry.

Ziyuglycoside II, one of the major effective ingredients of Sanguisorba officinalis L., had various pharmacological activities including anticancer, anti-inflammation and anti-oxidation, etc. Better understanding of the pharmacology and toxicology of ziyuglycoside II requires the detailed elucidation of its biologic fates in vivo. Herein, the metabolic fate of ziyuglycoside II in rats was investigated based on liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS). To accelerate and simplify the process of metabolite identification from complicated biological matrix, the sectional multiple filtering (SMF) scheme was designed according to the relationship among the molecular weight (MW), mass defect (MD) and retention time (tR) of the metabolites. SMF-I (MW: 700-850Da, MD: 0.40-0.45Da, tR: 4.0-10.0min), SMF-II (MW: 550-700Da, MD: 0.30-0.40Da, tR: 6.0-14.0min) and SMF-III (MW: 400-550Da, MD at 0.25-0.35Da, tR at 9.5-16.0min) were built and utilized to screen phase II conjugations and phase I redox metabolites and deglycosylated derivatives, respectively. As a result, dozens of metabolites, including glucuronic conjugates, hydroxylation, oxidization, dehydration and deglycosylation products, were rapidly discovered, classified and structural identified in rat urine and feces based on SMF scheme and accurate MS(1)/MS(2) information. Obviously, the SMF technique showed superior efficiency and selectivity in ziyuglycoside II metabolite identification. More importantly, SMF would find its extensive application in, but not limited to, the metabolic study for single drug or homologous compounds in traditional Chinese medicine.