A sensitive liquid chromatography-electrospray tandem mass spectrometric method for lancemaside A and its metabolites in plasma and a pharmacokinetic study in mice

Comprehensive metabolomics analysis based on UPLC-Q/TOF-MSE and the anti-COPD effect of different parts of Celastrus orbiculatus Thunb

The root, stem and leaf of Celastrus orbiculatus Thunb. (COT) have all been used as Chinese folk medicine. Aiming at revealing the secondary metabolites and screening the anti-COPD effect of COT, the comprehensive phytochemical and bioassay studies were performed. Based on the ultra-high performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MSE), the screening analysis of components in COT was conducted with the UNIFI platform, the metabolomics of the three parts were analyzed with multivariate statistical analysis. Cigarette smoke extract (CSE)-stimulated inflammatory model in A549 cells was used to investigate the biological effect of the three parts. A total of 120 compounds were identified or tentatively characterized from COT. Metabolomics analysis showed that the three parts of COT were differentiated, and there were 13, 8 and 5 potential chemical markers discovered from root, stem and leaf, respectively. Five robust chemical markers with high responses could be used for further quality control in different parts of COT. The root, stem and leaf of COT could evidently reduce the levels of pro-inflammatory factors in a dose-dependent way within a certain concentration range. The stem part had a stronger anti-COPD effect than root and leaf parts. This study clarified the structural diversity of secondary metabolites and the various patterns in different parts of COT, and provided a theoretical basis for further utilization and development of COT.

Chemical Metabolism of Xenobiotics by Gut Microbiota

Among the gut microbiota's newly explored roles in human biology is the ability to modify the chemical structures of foreign compounds (xenobiotics). A growing body of evidence has now provided sufficient acumen on the role of the gut microbiota on xenobiotic metabolism, which could have an intense impact on the therapy for various diseases in the future. Gut microbial xenobiotic metabolites have altered bioavailability, bioactivity and toxicity and can intervene with the actions of human xenobiotic-metabolizing enzymes to affect the destiny of other ingested molecules. These modifications are diverse and could lead to physiologically important consequences. In the current manuscript we aim to review the data currently available on how the gut microbiota directly modifies drugs, dietary compounds, chemicals, pollutants, pesticides and herbal supplements.

Mechanisms of gastrointestinal microflora on drug metabolism in clinical practice

Considered as an essential “metabolic organ”, intestinal microbiota plays a key role in human health and the predisposition to diseases. It is an aggregate genome of trillions of microorganisms residing in the human gastrointestinal tract. Since the 20th century, researches have showed that intestinal microbiome possesses a variety of metabolic activities that are able to modulate the fate of more than 30 approved drugs and immune checkpoint inhibitors. These drugs are transformed to bioactive, inactive, or toxic metabolites by microbial direct action or host-microbial co-metabolism. These metabolites are responsible for therapeutic effects exerted by these drugs or side effects induced by these drugs, even for death. In view of the significant effect on the drugs metabolism by the gut microbiota, it is pivotal for personalized medicine to explore additional drugs affected by gut microbiota and their involved strains for further making mechanism clear through suitable animal models. This review mainly focus on specific mechanisms involved, with reference to the current literature about drugs metabolism by related bacteria or its enzymes available.

Codonopsis lanceolata attenuates allergic lung inflammation by inhibiting Th2 cell activation and augmenting mitochondrial ROS dismutase (SOD2) expression

Allergic asthma is a chronic inflammatory disease induced by the inhalation of allergens, which trigger the activation of T helper type 2 (Th2) cells that release Th2 cytokines. Recently, herbal medicines are being considered a major source of novel agents to treat various diseases. In the present study, we evaluated the anti-asthmatic effects of a Codonopsis lanceolata extract (CLE) and the mechanisms involved in its anti-inflammatory effects. Treatment with CLE reduced infiltration of inflammatory cells, especially eosinophils, and the production of mucus in lung tissues. Levels of Th2 cytokines, such as IL-4, IL-5, and IL-13, and chemokines were also decreased following treatment with CLE. Moreover, Th2 cell proportion in vivo and differentiation in vitro were reduced as evidenced by the decreased expression of GATA3⁺. Furthermore, the expression of superoxide dismutase (SOD)2, a mitochondrial ROS (mROS) scavenger, was increased, which was related to Th2 cell regulation. Interestingly, treatment with CLE increased the number of macrophages in the lungs and enhanced the immune-suppressive property of macrophages. Our findings indicate that CLE has potential as a novel therapeutic agent to inhibit Th2 cell differentiation by regulating mROS scavenging.

Gut microbiota: a new angle for traditional herbal medicine research

Traditional Herbal Medicine (THM) has been used for thousands of years, and is popular worldwide due to its effectiveness in a variety of diseases.

Bi-directional drug-microbiome interactions of anti-diabetics

Type 2 diabetes (T2D) has become a global epidemic. Although several drugs are available to manage T2D, problems associated with person-to-person variability in drug efficacy and potential side-effects remain unresolved. Owing to the emerging role of the gut microbiome in obesity and T2D, the interaction between gut microbes and anti-diabetic drugs and its influence on drugs' functions remains of immediate research interest. On one hand, drugs can manipulate gut microbiome composition and metabolic capacity. Conversely, the metabolic activities of the microbiome and its metabolites can also influence drug metabolism and effects. Hence, understanding this bi-directional drug-microbiome interaction and how it influences the clinical outcomes of antidiabetic drugs can pave the way to develop next-generation strategies to ameliorate diabetes. This review presents evidences demonstrating the putative interactions between anti-diabetic drugs and the gut microbiome, and discusses the potential of microbiome modulators to manipulate drug-microbiome interactions and the drug metabolism.

Optimization and validation of extraction and quantification methods of antimalarial triterpenic esters in Keetia leucantha plant and plasma

The aim of this study is to develop validated methods for the extraction and quantification of antimalarial triterpene esters from Keetia leucantha and from plasma samples. These compounds, showing in vitro and in vivo antiplasmodial activities, were optimally extracted from Keetia leucantha twigs using ultrasounds with dichloromethane and from plasma using protein precipitation with acetonitrile. We then developed and validated HPLC-UV quantification methods, which proved to be selective, accurate, linear, true and precise, both in plant and plasma samples for the eight triterpenic esters in mixture. Based on the total error concept as decision criteria, the validated dosage ranges of the triterpene esters mixture were set between 14.68 and 73.37 μg/mL in plants and 15.90 and 106.01 μg/mL in plasma injected solutions, corresponding to 7.95 and 53.01 μg/mL in plasma. These reliable methods were used to determine effectively triterpene esters content in collected samples, that seems highly variable in plant extracts, and will be helpful to further investigate pharmacokinetics parameters of these interesting bioactive compounds.

Pharmacokinetics in Vitro and in Vivo of Two Novel Prodrugs of Oleanolic Acid in Rats and Its Hepatoprotective Effects against Liver Injury Induced by CCl4

Oleanolic acid (OA) is a well-known pentacyclic triterpenoid compound, which has been used as a dietary supplement and is supplied as an over-the-counter drug for the treatment of human liver diseases. These are reasons for the low bioavailability of OA which have restricted its wider application. In this study, two OA prodrugs (1,3-cyclic propanyl phosphate esters of OA) were designed and synthesized. The hepatoprotective effects of these prodrugs were evaluated against carbon tetrachloride (CCl4) induced liver injury in mice; the levels of alanine aminotransferase (ALT), lactic dehydrogenase (LDH), and aspartate aminotransferase (AST) were significantly increased, and the level of the hepatic malondialdehyde (MDA) was increased. The metabolism, in vitro, of the prodrugs was studied by incubation in rat liver microsome; the plasma pharmacokinetics and the biodistribution in vivo after intravenous (iv) injection to six rats were investigated, respectively. The prodrugs diminished gradually with time; most of the parent drugs were released within 30 min in vitro, and the presumed mechanism of the in vitro metabolism was confirmed. The plasma-concentration data in vivo was analyzed by a compartmental method: both the prodrugs and the corresponding released parent drugs existed at up to 48 h in rats. The t1/2 improved after intravenous administration in rats compared with direct injection of the parent drugs. All analyte concentrations were highest in the liver, and most of the prodrugs were excreted in feces (>47.11%). Therefore, 1,3-cyclic propanyl phosphate esters of OA can serve as a promising lead candidate for drugs.

Simultaneous determination of 3-O-acetyloleanolic acid and oleanolic acid in rat plasma using liquid chromatography coupled to tandem mass spectrometry

3-O-Acetyloleanolic acid (OAA) is a triterpenoid compound, and exerts an apoptosis in cancer cell lines, an inhibition of both atopic and allergic contact dermatitis in murine model, and a suppression of inflammatory bone loss in mice. OAA can be converted into oleanolic acid (OA) by hydrolysis in vivo, and OA exhibits several pharmacological effects as well. A liquid chromatographic method using tandem mass spectrometry (MS/MS) was developed for the simultaneous determination of OAA and OA in rat plasma. After liquid-liquid extraction with ethylacetate, both substances were chromatographed on a reversed phase column with a mobile phase of 0.1% formic acid aqueous solution and acetonitrile (1:9, v/v). The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods. This analytical method was successfully applied to monitor plasma concentrations of both substances over time following an intravenous administration of OAA in rats.

LFP-20, a porcine lactoferrin peptide, ameliorates LPS-induced inflammation via the MyD88/NF-κB and MyD88/MAPK signaling pathways

LFP-20 is one of the 20 amino acid anti-microbial peptides identified in the N terminus of porcine lactoferrin. Apart from its extensively studied direct anti-bacterial activity, its potential as an activator of immune-related cellular functions is unknown. Therefore, this study investigated its anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated pig alveolar macrophages in vitro and systemic inflammation in an in vivo mouse model. We found that the inhibitory effects of LFP-20 on production of pro-inflammatory cytokines were independent of its LPS-binding activity. However, they were associated with NF-κB and MAPK-dependent signaling. Furthermore, LFP-20 might directly influence MyD88 levels to block its interaction with NF-κB and MAPK-dependent signaling molecules that might alter LPS-mediated inflammatory responses in activated macrophages. Taken together, our data indicated that LFP-20 prevents the LPS-induced inflammatory response by inhibiting MyD88/NF-κB and MyD88/MAPK signaling pathways, and sheds light on the potential use of LFP-20 in the therapy of LPS-mediated sepsis.

Gut Microbiota-Mediated Drug-Antibiotic Interactions

Xenobiotic metabolism involves the biochemical modification of drugs and phytochemicals in living organisms, including humans and other animals. In the intestine, the gut microbiota catalyzes the conversion of hydrophilic drugs into absorbable, hydrophobic compounds through hydroxyzation and reduction. Drugs and phytochemicals are transformed into bioactive (sulfasalazine, lovastatin, and ginsenoside Rb1), bioinactive (chloramphenicol, ranitidine, and metronidazole), and toxic metabolites (nitrazepam), thus affecting the pharmacokinetics of the original compounds. Antibiotics suppress the activities of drug-metabolizing enzymes by inhibiting the proliferation of gut microbiota. Antibiotic treatment might influence xenobiotic metabolisms more extensively and potently than previously recognized and reduce gut microbiota-mediated transformation of orally administered drugs, thereby altering the systemic concentrations of intact drugs, their metabolites, or both. This review describes the effects of antibiotics on the metabolism of drugs and phytochemicals by the gut microbiota.

Isolation, characterization, and in rats plasma pharmacokinetic study of a new triterpenoid saponin from Dianthus superbus

One new oleanolic acid triterpenoid saponin, 3-O-β-D-glucopyranosyl olean-11, 13(18)-diene-23,28-dioic acid, (hereafter referred to as DS-1) was isolated from the traditional Chinese medicinal plant Dianthus superbus (D. superbus). DS-1 plays an important role in the bioactivity of D. superbus. Thus, a sensitive, reliable and accurate reversed-phased liquid chromatography with tandem mass spectrometry (LC-MS/MS) in negative ion mode was developed and validated for the quantification and pharmacokinetic study of DS-1 in rats plasma. The pharmacokinetic profile showed that DS-1 was rapidly absorbed and eliminated in plasma, indicating that significant accumulation of the compound in biological specimen is unlikely. In addition, poor absorption into systemic circulation was observed after oral administration of DS-1, resulting in low absolute bioavailability (0.92 %).

A UPLC-MS/MS method for in vivo and in vitro pharmacokinetic studies of psoralenoside, isopsoralenoside, psoralen and isopsoralen from Psoralea corylifolia extract

ETHNOPHARMACOLOGICAL RELEVANCE

The dried fruit of Psoralea corylifolia L. has been used to prevent and treat vitiligo, osteoporosis, arthralgia and asthma in Traditional Chinese Medicine for some 1600 years. Psoralen (P), isopsoralen (IP), psoralenoside (PO) and isopsoralenoside (IPO) are the major coumarins and coumarin-related benzofuran glycosides in Psoraleae Fructus, which have been reported to show estrogen-like activity, osteoblastic proliferation accelerating activity, antitumor effects and antibacterial activity. The first aim of this study is to develop a rapid, sensitive and selective ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) approach for simultaneous determination of PO, IPO, P and IP in rat plasma and samples collected from in vitro incubation experiments. The second aim is to investigate the pharmacokinetic properties of PO, IPO, P and IP after oral administration of Psoralea corylifolia extract (PCE) to rats. The third aim is to confirm the biotransformation of PO to P or IPO to IP under gastrointestinal conditions.

MATERIALS AND METHODS

A UPLC-MS/MS method with a C18 column and a mobile phase of methanol-0.1% aqueous formic acid was validated according to the criteria in FDA guidelines about bioanalytical method, which was developed to investigate the pharmacokinetic behavior of PO, IPO, P and IP from PCE and the metabolic pathways of PO to P or IPO to IP.

RESULTS

The criteria for establishment of a new UPLC-MS/MS method including selectivity, linearity, accuracy, precision, extraction recovery, matrix effect and stability were validated. This method was successfully applied to the quantitative determination of PO, IPO, P and IP in biological samples collected from both in vitro incubations and in vivo rat experiments. After oral administration of PCE to rat, pharmacokinetic parameters of these four compounds indicated that in vivo biotransformation may occur between PO and P or IPO and IP. Purified benzofuran glycosides fraction (PBGF), containing only PO and IPO, was orally administered to rats to further confirm the biotransformation of PO to P or IPO to IP under gastrointestinal conditions. An in vitro incubation study elucidated that PO and IPO were metabolized to P and IP by intestinal microflora through de-glucosylation.

CONCLUSIONS

This paper developed a rapid, sensitive and selective UPLC-MS/MS method for simultaneous determination of PO, IPO, P and IP from PCE in biological samples, and investigated on their comprehensive in vivo and in vitro pharmacokinetic studies. These obtained results showed that the metabolism by intestinal bacteria plays an important role in pharmacological effects of orally administered PCE.

Inhibitory effect of echinocystic acid on 12-O-tetradecanoylphorbol-13-acetate-induced dermatitis in mice

The rhizome of Codonopsis lanceolata (family Campanulaceae), which contains lancemaside A as a main constituent, is frequently used in the traditional Chinese medicine for the treatment of inflammatory diseases. Lancemaside A exhibits anti-inflammatory effect in vitro and in vivo. However, orally administered lancemaside A is metabolized to echinocystic acid by the intestinal microflora and the metabolite is absorbed into the blood. Therefore, to understand whether echinocystic acid is effective against skin inflammatory diseases, we assessed its inhibitory effect against 12-O-tetra decanoylphorbol-13-acetate (TPA)-induced ear inflammation in mice. Topically administered echinocystic acid potently suppressed TPA-induced ear swelling. The suppression rates at 0.05 and 0.10 % concentrations were 65 and 73 %, respectively. Echinocystic acid also inhibited TPA-induced myeloperoxidase activity, as well as COX-2, iNOS, TNF-α and IL-1β expressions. Echinocystic acid inhibited NF-κB in TPA-treated mouse ears, as well as in lipopolysaccharide-stimulated peritoneal macrophages. Its potency is comparable with that of dexamethasone. These findings indicate that echinocystic acid may ameliorate inflammatory diseases, such as dermatitis.

Lancemaside A inhibits microglial activation via modulation of JNK signaling pathway

Microglial activation plays an important role in neurodegenerative diseases. Thus, controlling microglial activation is considered to be a promising therapeutic target for neurodegenerative diseases. In the present study, we found that lancemaside A, a triterpenoid saponin isolated from Codonopsislanceolata, inhibited iNOS and proinflammatory cytokines in LPS-stimulated BV2 microglial cells. By analyzing molecular mechanisms underlying the anti-inflammatory effects of lancemaside A, we found that lancemaside A selectively inhibited LPS-induced JNK phosphorylation among the three types of MAP kinases. A JNK-specific inhibitor, SP600125, like lancemaside A, significantly inhibited not only NO, TNF-α, and IL-6 productions, but also NF-κB and AP-1 activities, suggesting that JNK inhibition is largely involved in the anti-inflammatory mechanism of lancemaside A. Interestingly, both the lancemaside A and SP600125 inhibited ROS production by suppressing the expression and/or phosphorylation of NADPH oxidase subunit proteins, such as p47(phox), p67(phox), and gp91(phox). The antioxidant effects of lancemaside A and SP600125 appear to be related with an increase of hemeoxygenase-1 expression by both agents. Finally, we demonstrated the neuroprotective effects of lancemaside A and SP600125 in microglia-neuron coculture systems. Collectively, our data suggest that JNK pathway plays a key role mediating anti-inflammatory effects of lancemaside A in LPS-stimulated microglia.

Lancemaside A isolated from Codonopsis lanceolata and its metabolite echinocystic acid ameliorate scopolamine-induced memory and learning deficits in mice

The rhizome of Codonopsis lanceolata (family Campanulaceae), which contains lancemaside A as a main constituent, has been used as herbal medicine to treat inflammation, insomnia, and hypomnesia. Lancemaside A and echinocystic acid, which is its metabolite by intestinal microflora, potently inhibited acetylcholinesterase activity in a dose-dependent manner, with IC₅₀ value 13.6 μM and 12.2 μM, respectively. Its inhibitory potency is comparable with that of donepezil (IC₅₀=10.9 μM). Lancemaside A and echinocystic acid significantly reversed scopolamine-induced memory and learning deficits on passive avoidance task. Lancemaside A orally administered 5h before treatment with scopolamine reversed scopolamine-induced memory and learning deficits more potently than one orally administered 1h before. Echinocystic acid more potently reversed it than lancemaside A. Lancemaside A and echinocystic acid significantly reversed scopolamine-induced memory and learning deficits on the Y-maze and Morris water maze tasks. Lancemaside A and echinocystic acid also increased the expression of brain-derived neurotrophic factor (BDNF) and phosphorylated cAMP response element binding protein (p-CREB). Based on these findings, orally administered lancemaside A may be metabolized to echinocystic acid, which may be absorbed into the blood and ameliorate memory and learning deficits by inhibiting AChE activity and inducing BDNF and p-CREB expressions.

Pleckstrin homology domain of Akt kinase: a proof of principle for highly specific and effective non-enzymatic anti-cancer target

While pharmacological inhibition of Akt kinase has been regarded as a promising anti-cancer strategy, most of the Akt inhibitors that have been developed are enzymatic inhibitors that target the kinase active site of Akt. Another key cellular regulatory event for Akt activation is the translocation of Akt kinase to the cell membrane from the cytoplasm, which is accomplished through the pleckstrin homology (PH) domain of Akt. However, compounds specifically interacting with the PH domain of Akt to inhibit Akt activation are currently limited. Here we identified a compound, lancemaside A (LAN-A), which specifically binds to the PH domain of Akt kinase. First, our mass spectra analysis of cellular Akt kinase isolated from cells treated with LAN-A revealed that LAN-A specifically binds to the PH domain of cellular Akt kinase. Second, we observed that LAN-A inhibits the translocation of Akt kinase to the membrane and thus Akt activation, as examined by the phosphorylation of various downstream targets of Akt such as GSK3β, mTOR and BAD. Third, in a co-cultured cell model containing human lung epithelial cancer cells (A549) and normal human primary lung fibroblasts, LAN-A specifically restricts the growth of the A549 cells. LAN-A also displayed anti-proliferative effects on various human cancer cell lines. Finally, in the A549-luciferase mouse transplant model, LAN-A effectively inhibited A549 cell growth with little evident cytotoxicity. Indeed, the therapeutic index of LAN-A in this mouse model was >250, supporting that LAN-A is a potential lead compound for PH domain targeting as a safe anti-cancer Akt inhibitor.

Antibiotics attenuate anti-scratching behavioral effect of ginsenoside Re in mice

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Panax ginseng CA Meyer (ginseng) has been used for diabetes, cancer, stress and allergic diseases in the traditional Chinese medicine.

AIM OF THE STUDY

To understand the role of intestinal microflora in the pharmacological effect of ginsenoside Re, which is a main constituent of ginseng, we investigated its anti-scratching behavioral effect in the mice treated with or without antibiotics.

MATERIALS AND METHODS

Ginsenoside Re was orally administered to the mice treated with antibiotics (cefadroxil, oxytetracycline and erythromycin mixture (COE), streptomycin or/and tetracycline) and then investigated the relationship between ginsenoside Re-metabolizing β-glucosidase and α-rhamnosidase activities of intestinal microflora and its antiscratching behavioral effect. The anti-scratching behavioral effects of ginsenosides were investigated in the increments of 1 h and 6 h after their oral administrations. The scratching behavioral frequency was measured for 1 h after treatment with histamine.

RESULTS

Ginsenoside Re inhibited histamine-induced scratching behavior in mice. The anti-scratching behavioral effect of ginsenoside Re was more potent 6 h after its oral administration than 1 h after. However, its inhibitory effect was significantly attenuated in mice treated with COE, but it nearly was not affected in mice treated with streptomycin and/or tetracycline. Treatment with COE also significantly lowered fecal ginsenoside Re-metabolizing β-glucosidase and α-rhamnosidase activities in mice, as well as fecal metabolic activity of ginsenoside Re to ginsenoside Rh1. The anti-scratching behavioral effect of ginsenoside Rh1, a metabolite of ginsenoside Re by intestinal microflora, was superior to that of ginsenoside Re. Ginsenoside Rh1 potently inhibited the expression of IL-4 and TNF-α, as well as the activation of NF-κB and c-jun activation in histamine-stimulated scratching behavioral mice.

CONCLUSION

Ginsenoside Re may be metabolized to ginsenoside Rh1 by intestinal microflora, which enhances its anti-scratching behavioral effect by inhibiting NF-κB and c-jun activations.

Echinocystic acid ameliorates lung inflammation in mice and alveolar macrophages by inhibiting the binding of LPS to TLR4 in NF-κB and MAPK pathways

Orally administered lancemaside A, which is isolated from Codonopsis lanceolata (family Campanulaceae), showed anti-colitic effect in mice. However, its metabolite echinocystic acid was absorbed into the blood. Therefore, its anti-inflammatory effects were investigated in lipopolysaccharide (LPS)-stimulated alveolar macrophages in vitro and acute lung injury in vivo. Alveolar macrophages from mice were stimulated with LPS and were treated with echinocystic acid. Acute lung injury was induced by intratracheal administration of LPS in mice. Mice were treated with echinocystic acid or dexamethasone. Echinocystic acid potently suppressed the production of the pro-inflammatory cytokines, TNF-α and IL-1β, as well as of the activations of NF-κB and MAPKS, in LPS-stimulated alveolar macrophages. Echinocystic acid also down-regulated the production of inflammatory markers, which included inducible nitric oxide synthase and cyclooxygenase-2, as well as the inflammatory mediators, nitric oxide and prostaglandin E(2), in LPS-stimulated alveolar macrophages. Echinocystic acid also inhibited the activation of IL-1 receptor-associated kinases, and the activation of mitogen-activated protein kinases in LPS-stimulated alveolar macrophages. Furthermore, echinocystic acid potently inhibited the interaction between LPS and TLR4 in alveolar macrophages transfected with or without MyD88 siRNA, although it did not inhibit the binding in the macrophages transfected with TLR4 siRNA. Echinocystic acid suppressed LPS-induced acute lung inflammation in mice, as well as the expression of pro-inflammatory cytokines, such as IL-1β and TNF-α, and their transcription factor, NF-κB. On the basis of these findings, echinocystic acid, a metabolite of lancemaside A, may express anti-inflammatory effects by inhibiting the binding of LPS to TLR4 on macrophages.