Highly selective antibacterial activity of novel alkyl quinolone alkaloids from a Chinese herbal medicine, Gosyuyu (Wu-Chu-Yu), against Helicobacter pylori in vitro

Helicobacter pylori infection in humans and phytotherapy, probiotics, and emerging therapeutic interventions: a review

The global prevalence of Helicobacter pylori (H. pylori) infection remains high, indicating a persistent presence of this pathogenic bacterium capable of infecting humans. This review summarizes the population demographics, transmission routes, as well as conventional and novel therapeutic approaches for H. pylori infection. The prevalence of H. pylori infection exceeds 30% in numerous countries worldwide and can be transmitted through interpersonal and zoonotic routes. Cytotoxin-related gene A (CagA) and vacuolar cytotoxin A (VacA) are the main virulence factors of H. pylori, contributing to its steep global infection rate. Preventative measures should be taken from people's living habits and dietary factors to reduce H. pylori infection. Phytotherapy, probiotics therapies and some emerging therapies have emerged as alternative treatments for H. pylori infection, addressing the issue of elevated antibiotic resistance rates. Plant extracts primarily target urease activity and adhesion activity to treat H. pylori, while probiotics prevent H. pylori infection through both immune and non-immune pathways. In the future, the primary research focus will be on combining multiple treatment methods to effectively eradicate H. pylori infection.

Traditional Chinese medicine Euodiae Fructus: botany, traditional use, phytochemistry, pharmacology, toxicity and quality control

Euodiae Fructus, referred to as "Wuzhuyu" in Chinese, has been used as local and traditional herbal medicines in many regions, especially in China, Japan and Korea, for the treatment of gastrointestinal disorders, headache, emesis, aphtha, dermatophytosis, dysentery, etc. Substantial investigations into their chemical and pharmacological properties have been performed. Recently, interest in this plant has been focused on the different structural types of alkaloids like evodiamine, rutaecarpine, dehydroevodiamine and 1-methyl-2-undecyl-4(1H)-quinolone, which exhibit a wide range of pharmacological activities in preclinical models, such as anticancer, antibacterial, anti-inflammatory, anti-cardiovascular disease, etc. This review summarizes the up-to-date and comprehensive information concerning the botany, traditional uses, phytochemistry, pharmacology of Euodiae Fructus together with the toxicology and quality control, and discusses the possible direction and scope for future research on this plant.

Zuogui Jiangtang Shuxin formula Ameliorates diabetic cardiomyopathy mice via modulating gut-heart axis

BACKGROUND

There is growing evidence demonstrating that the gut microbiota plays a crucial role in multiple endocrine disorders, including diabetic cardiomyopathy (DCM). Research shows that the Chinese herb reduces disease occurrence by regulating gut microbiota. Zuogui Jiangtang Shuxin formula (ZGJTSXF), a Chinese medicinal formula, has been clinically used for treatment of DCM for many years. However, there is still no clear understanding of how ZGJTSXF treatment contributes to the prevention and treatment of DCM through its interaction with gut microbiota and metabolism.

METHODS

In this study, mice models of DCM were established, and ZGJTSXF's therapeutic effects were assessed. Specifically, serum glycolipid, echocardiography, histological staining, myocardial apoptosis rate were assessed. Using 16s rRNA sequencing and high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), we determined the impact of ZGJTSXF on the structure of gut microbiota and content of its metabolite TMAO. The mechanism of ZGJTSXF action on DCM was analyzed using quantitative real-time PCR and western blots.

RESULTS

We found that ZGJTSXF significantly ameliorated DCM mice by modulating gut-heart axis: ZGJTSXF administration improved glycolipid levels, heart function, cardiac morphological changes, inhibited cardiomyocytes apoptosis, and regulate the gut microbiota in DCM mice. Specifically, ZGJTSXF treatment reverse the significant changes in the abundance of certain genera closely related to DCM phenotype, including Lactobacillus, Alloprevotella and Alistipes. Furthermore, ZGJTSXF alleviated DCM in mice by blunting TMAO/PERK/FoxO1 signaling pathway genes and proteins.

CONCLUSION

ZGJTSXF administration could ameliorate DCM mice by remodeling gut microbiota structure, reducing serum TMAO generation and suppressing TMAO/PERK/FoxO1 signaling pathway.

Anti-Helicobacter pylori, anti-Inflammatory, and Antioxidant Activities of Trunk Bark of Alstonia boonei (Apocynaceae)

An ulcer is an erosion of the gastric mucosa that occurs following an imbalance between the aggression and protective factors and/or an infection with Helicobacter pylori (H. pylori). About 90-100% of duodenal ulcers and 70-80% of gastric ulcers are caused by H. pylori. The objective of this work was to evaluate in vitro the anti-H. pylori activity and then the anti-inflammatory and antioxidant properties of aqueous and methanol extracts of Alstonia boonei. The anti-H. pylori tests (CMI and antiureasic activity) were determined using the agar well diffusion method, the microbroth dilution method, and the measurement of ammonia production by the indophenol method; the anti-inflammatory properties were evaluated by inhibition of proteinases, denaturation of albumin, production of NO by macrophages, cell viability, and hemolysis of red blood cells by heat; then, the antioxidant properties were evaluated by the FRAP method (ferric reducing antioxidant power) and the DPPH (1,1-diphenyl-2-picrylhydrazyl) test. The results show that the best trapping of the DPPH radical was obtained with the methanol extract (EC₅₀ = 8.91 μg/mL) compared to the aqueous extract (EC₅₀ = 19.86 μg/mL). The methanol extract also showed greater iron-reducing activity than the aqueous extract and vitamin C. Furthermore, at the concentration of 200 μg/mL, the methanol extract showed a percentage (96.34%) strains of H. pylori higher than that of the aqueous extract (88.52%). The MIC₉₀ of the methanol extract was lower than that of the aqueous extract. The methanol extract showed a higher percentage inhibition (85%) of urease than the aqueous extract (73%). The methanol extract at a concentration of 1000 μg/mL showed the greatest ability to inhibit proteinase activity, albumin denaturation, and red blood cell hemolysis; on the other hand, maximum cell viability and greater production of nitrite oxide by macrophages were obtained with the aqueous extract. Aqueous and methanol extracts of Alstonia boonei possess anti-H. pylori which would probably be linked to their antioxidant and anti-inflammatory properties.

Biology of quinoline and quinazoline alkaloids

Quinoline and quinazoline alkaloids, two important classes of N-based heterocyclic compounds, have attracted scientific and popular interest worldwide since the 19th century. More than 600 compounds have been isolated from nature to date. To build on our two prior reviews, we reexamined the promising molecules described in previous reports and provided updated literature on novel quinoline and quinazoline alkaloids isolated over the past 5 years. This chapter reviews and discusses 205 molecules with a broad range of bioactivities, including antiparasitic and insecticidal, antibacterial and antifungal, cardioprotective, antiviral, anti-inflammatory, and other effects. This survey should provide new clues or possibilities for the discovery of new and better drugs from the original naturally occurring quinoline and quinazoline alkaloids.

Application of traditional Chinese medicine in treatment of Helicobacter pylori infection

Helicobacter pylori (H. pylori) has a high rate of infection and antibiotic resistance and poses a serious threat to human life. One of the main strategies to overcome drug resistance is to develop new treatment plans. Traditional Chinese medicine (TCM) that is commonly used to treat many diseases in China can reduce drug resistance and increase the eradication rate of H. pylori. In this paper, we review the research progress on TCM in the treatment of H. pylori infection. The mechanism of action of TCM is reviewed and research and applications of TCM in the treatment of H. pylori are demonstrated. Finally, we discuss problems confronting the use of TCM for the treatment of H. pylori infection and propose possible solutions. In addition, the plans of TCM in H. pylori treatment were also screened: Dampness-heat syndrome in the spleen and stomach, deficiency of spleen and stomach, and cold-heat complicated syndrome, and the effective components therein are studied. The antibacterial effect of TCM is relatively slow; for rapid improvement of the treatment effect of refractory H. pylori gastritis, we provide an appropriate treatment regime combining TCM and Western medicine with immune-regulatory and synergistic antibacterial effects.

Potential utility of nano-based treatment approaches to address the risk of Helicobacter pylori

INTRODUCTION

Helicobacter pylori (H. pylori) has occupied a significant place among infectious pathogens and it has been documented as a leading challenge due to its higher resistance to the commonly used drugs, higher adaptability, and lower targeting specificity of the available drugs.

AREAS COVERED

New treatment strategies are urgently needed in order to improve the current advancement in modern medicine. Nanocarriers have gained an advantage of drug encapsulation and high retention time in the stomach with a prolonged drug release rate at the targeted site. This article aims to highlight the recent advances in nanotechnology with special emphasis on metallic, polymeric, lipid, membrane coated, and target-specific nanoparticles (NPs), as well as, natural products for treating H. pylori infection. We discussed a comprehensive approach to understand H. pylori infection and elicits to rethink about the increasing threat posed by H. pylori and its treatment strategies.

EXPERT OPINION

To address these issues, nanotechnology has got huge potential to combat H. pylori infection and has made great progress in the field of biomedicine. Moreover, combinatory studies of natural products and probiotics in conjugation with NPs have proven efficiency against H. pylori infection, with an advantage of lower cytotoxicity, minimal side effects, and stronger antibacterial potential.[Figure: see text].

Herbal Medicine, Gut Microbiota, and COVID-19

Coronavirus Disease 19 (COVID-19) is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has grown to a worldwide pandemic with substantial mortality. The symptoms of COVID-19 range from mild flu-like symptoms, including cough and fever, to life threatening complications. There are still quite a number of patients with COVID-19 showed enteric symptoms including nausea, vomiting, and diarrhea. The gastrointestinal tract may be one of the target organs of SARS-CoV-2. Angiotensin converting enzyme 2 (ACE2) is the main receptor of SARS-CoV-2 virus, which is significantly expressed in intestinal cells. ACE2 links amino acid malnutrition to microbial ecology and intestinal inflammation. Intestinal flora imbalance and endotoxemia may accelerate the progression of COVID-19. Many herbs have demonstrated properties relevant to the treatment of COVID-19, by supporting organs and systems of the body affected by the virus. Herbs can restore the structure of the intestinal flora, which may further modulate the immune function after SARS-CoV-2 infection. Regulation of intestinal flora by herbal medicine may be helpful for the treatment and recovery of the disease. Understanding the role of herbs that regulate intestinal flora in fighting respiratory virus infections and maintaining intestinal flora balance can provide new ideas for preventing and treating COVID-19.

Presence of the Hmq System and Production of 4-Hydroxy-3-Methyl-2-Alkylquinolines Are Heterogeneously Distributed between Burkholderia cepacia Complex Species and More Prevalent among Environmental than Clinical Isolates

The Burkholderia cepacia complex (Bcc) comprises several species of closely related, versatile bacteria. Some Bcc strains produce 4-hydroxy-3-methyl-2-alkylquinolines (HMAQs), analogous to the 4-hydroxy-2-alkylquinolines of Pseudomonas aeruginosa. Using in silico analyses, we previously estimated that the hmqABCDEFG operon, which encodes enzymes involved in the biosynthesis of HMAQs, is carried by about one-third of Bcc strains, with considerable inter- and intraspecies variability. In the present study, we investigated by PCR, using consensus primers, the distribution of hmqABCDEFG in a collection of 312 Bcc strains (222 of clinical and 90 of environmental origins) belonging to 18 Bcc species. We confirmed that this operon is not distributed evenly among Bcc species. Among the 30% of strains bearing the hmqABCDEFG operon, we found that 92% of environmental isolates and 82% of clinically isolated Bcc strains produce levels of HMAQs detectable by liquid chromatography-mass spectrometry in at least one of the tested culture conditions. Among the hmqABCDEFG-positive but HMAQ-negative strains, none expressed the hmqA gene under the specified culture conditions. Interestingly, the hmqABCDEFG operon is more prevalent among plant root environment species (e.g., Burkholderia ambifaria and Burkholderia cepacia) and absent in species commonly found in chronically colonized individuals with cystic fibrosis (e.g., Burkholderia cenocepacia and Burkholderia multivorans), suggesting a role for the Hmq system in niche adaptation. We investigated the impact of the Hmq system on plant growth promotion and found that Pisum sativum root development by B. ambifaria required a functional HMAQ system.

IMPORTANCE Environmental bacteria belonging to the various closely related species forming the Burkholderia cepacia complex (Bcc) can infect plants and animals, including humans. Their pathogenicity is regulated by intercellular communication, or quorum sensing, allowing them to collaborate instead of acting individually. Bcc organisms generally exploit interacting quorum sensing systems based on N-acyl-homoserine lactones as signaling molecules. Several Bcc strains also carry an hmqABCDEFG operon responsible for the biosynthesis of 4-hydroxy-3-methyl-2-alkylquinolines (HMAQs), molecules analogous to the Pseudomonas quinolone signal (PQS) system of P. aeruginosa. Our finding that the prevalences of the Hmq system and HMAQ production are very different between various Bcc species suggests a key role in niche adaptation or pathogenicity. This is supported by a significant reduction in plant growth promotion in the absence of HMAQ production for a beneficial Bcc strain.

Evodiamine Inhibits Helicobacter pylori Growth and Helicobacter pylori-Induced Inflammation

Helicobacter pylori (H. pylori) classified as a class I carcinogen by the World Health Organization (WHO) plays an important role in the progression of chronic gastritis and the development of gastric cancer. A major bioactive component of Evodia rutaecarpa, evodiamine, has been known for its anti-bacterial effect and anti-cancer effects. However, the inhibitory effect of evodiamine against H. pylori is not yet known and the inhibitory mechanisms of evodiamine against gastric cancer cells are yet to be elucidated concretely. In this study, therefore, anti-bacterial effect of evodiamine on H. pylori growth and its inhibitory mechanisms as well as anti-inflammatory effects and its mechanisms of evodiamine on H. pylori-induced inflammation were investigated in vitr. Results of this study showed the growth of the H. pylori reference strains and clinical isolates were inhibited by evodiamine. It was considered one of the inhibitory mechanisms that evodiamine downregulated both gene expressions of replication and transcription machineries of H. pylori. Treatment of evodiamine also induced downregulation of urease and diminished translocation of cytotoxin-associated antigen A (CagA) and vacuolating cytotoxin A (VacA) proteins into gastric adenocarcinoma (AGS) cells. This may be resulted from the reduction of CagA and VacA expressions as well as the type IV secretion system (T4SS) components and secretion system subunit protein A (SecA) protein which are involved in translocation of CagA and VacA into host cells, respectively. In particular, evodiamine inhibited the activation of signaling proteins such as the nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) and the mitogen-activated protein kinase (MAPK) pathway induced by H. pylori infection. It consequently might contribute to reduction of interleukin (IL)-8 production in AGS cells. Collectively, these results suggest anti-bacterial and anti-inflammatory effects of evodiamine against H. pylori.

Phytotherapeutic modalities for the management of Helicobacter pylori associated peptic ulcer

Due to an imbalance between aggressive factors known as hydrochloric acid (HCl), pepsin, leukotrienes, refluxed bile, defensive factors and reactive oxygen species, the peptic ulcer is formed in the stomach and duodenum which mostly include the function of prostaglandins, mucus bicarbonate barrier, enzymatic antioxidants, and some growth factors. H. pylori infection remained one of the considerable causes of peptic ulcer as it caused hypochlorhydria and struck off the defense mechanism of the stomach. The nonsteroidal anti-inflammatory drugs (NSAIDs) and stress are the most prevailing causes of peptic ulcer disease. Lack of physical exercise, little rest and due to poor leisure cause the peptic ulcer disease. Candies, chocolate, coffee, cigarettes, stress, and alcohol are the cause of peptic ulceration and suppression of acid in the stomach due to the utilization of antacid medication. Most of the ancient medical practices in the traditional alternative medicinal system include Unani, Ayurveda, Siddha, Homeopathy, Naturopathy, Chinese customary medicine, African conventional medicine, and Native American medicine. Without a hostile effect, the rate of curing the disease is the significance of natural products research. Peptic ulcer disease is the widespread nature of peptic ulcer in all class of population, which mostly may be due to rapidly changing the food habits and stress, causing the imbalance between gastric offensive and defensive factors. Curcuma longa is the most effective plant for the cure of peptic ulcer. Curcuma longa has anti-inflammatory and antioxidant activity. Curcuma longa remarkably reduces the level of inflammatory mediator (IL1) and (TNF) which was increased during the formation of an ulcer. In the rhizome of Curcuma longa, yellow pigment is present and widely used for the treatment of ulcer and decrease the inflammatory response. Symptoms include abdominal pain after taking a meal, nausea, vomiting, Anorexia and lose weight.

Naturally-Occurring Alkaloids of Plant Origin as Potential Antimicrobials against Antibiotic-Resistant Infections

Antibiotic resistance is now considered a worldwide problem that puts public health at risk. The onset of bacterial strains resistant to conventional antibiotics and the scarcity of new drugs have prompted scientific research to re-evaluate natural products as molecules with high biological and chemical potential. A class of natural compounds of significant importance is represented by alkaloids derived from higher plants. In this review, we have collected data obtained from various research groups on the antimicrobial activities of these alkaloids against conventional antibiotic-resistant strains. In addition, the structure–function relationship was described and commented on, highlighting the high potential of alkaloids as antimicrobials.

Synthesis and Antimicrobial Activity of Novel 4-Hydroxy-2-quinolone Analogs

Alkyl quinolone has been proven to be a privileged scaffold in the antimicrobial drug discovery pipeline. In this study, a series of new 4-hydroxy-2-quinolinone analogs containing a long alkyl side chain at C-3 and a broad range of substituents on the C-6 and C-7 positions were synthesized. The antibacterial and antifungal activities of these analogs against Staphylococcus aureus, Escherichia coli, and Aspergillus flavus were investigated. The structure-activity relationship study revealed that the length of the alkyl chain, as well as the type of substituent, has a dramatic impact on the antimicrobial activities. Particularly, the brominated analogs 3j with a nonyl side chain exhibited exceptional antifungal activities against A. flavus (half maximal inhibitory concentration (IC₅₀) = 1.05 µg/mL), which surpassed that of the amphotericin B used as a positive control. The antibacterial activity against S. aureus, although not as potent, showed a similar trend to the antifungal activity. The data suggest that the 4-hydroxy-2-quinolone is a promising framework for the further development of new antimicrobial agents, especially for antifungal treatment.

Plants against Helicobacter pylori to combat resistance: An ethnopharmacological review

Worldwide, Helicobacter pylori (H. pylori) is regarded as the major etiological agent of peptic ulcer and gastric carcinoma. Claiming about 50 percent of the world population is infected with H. pylori while therapies for its eradication have failed because of many reasons including the acquired resistance against its antibiotics. Hence, the need to find new anti-H.pylori medications has become a hotspot with the urge of searching for alternative, more potent and safer inhibitors. In the recent drug technology scenario, medicinal plants are suggested as repositories for novel synthetic substances. Hitherto, is considered as ecofriendly, simple, more secure, easy, quick, and less toxic traditional treatment technique. This review is to highlight the anti-H. pylori medicinal plants, secondary metabolites and their mode of action with the aim of documenting such plants before they are effected by cultures and traditions that is expected as necessity.

Treatment strategies and preventive methods for drug-resistant Helicobacter pylori infection

The infection and drug resistance rates of Helicobacter pylori (H. pylori) are high and must be prevented and treated by better strategies. Based on recent research advances in this field as well as the results from our team and those on traditional Chinese medicine, we review the causes of drug resistance, and prevention and treatment strategies for drug-resistant H. pylori infection, with an aim to make suggestions for the development of new drugs, such as establishment of new target identification and screening systems, modification of existing drug structures, use of new technologies, application of natural products, and using a commercial compound library. This article may provide reference for eradication of drug-resistant H. pylori.

Facile access to evodiakine enabled by aerobic copper-catalyzed oxidative rearrangement

Oxidation as a fundamentally important method for the synthesis of complex structures is difficult to achieve in a selective manner. Evodiakine, a complex natural product possessing an unprecedented ring system (6/5/5/7/6), has a high oxidation state without a practical solution. Herein, we report the first synthesis of evodiakine via aerobic copper-catalyzed late-stage functionalization of evodiamine.

Antiulcer Agents: From Plant Extracts to Phytochemicals in Healing Promotion

In this narrative review, we have comprehensively reviewed the plant sources used as antiulcer agents. From traditional uses as herbal remedies, we have moved on to preclinical evidence, critically discussing the in vitro and in vivo studies focusing on plant extracts and even isolated phytochemicals with antiulcerogenic potential. A particular emphasis was also paid to Helicobacter pylori activity, with emphasis on involved mechanisms of action. Lastly, the issue of safety profile of these plant products has also been addressed.

Natural Products for the Prevention and Management of Helicobacter pylori Infection

Helicobacter pylori is the main pathogen that induces chronic gastritis, peptic ulcers, atrophic gastritis, and other gastric disorders, and it is classified as a group I carcinogen. To eradicate H. pylori infection, triple therapy consisting of two antibiotics and a proton pump inhibitor is the most widely recommended first-line therapeutic strategy. Antimicrobial resistance to antibiotics contained in triple therapy could lead to therapeutic regimen failures. Recent studies showed that many natural products, including fruits, vegetables, spices, and medicinal plants, possess inhibitory effects on H. pylori, indicating their potential to be alternatives to prevent and manage H. pylori infection. This review summarizes the effects of natural products on H. pylori infection and highlights the mechanisms of action.

Biologically active quinoline and quinazoline alkaloids part I

Quinoline and quinazoline alkaloids, two important classes of N-based heterocyclic compounds, have attracted tremendous attention from researchers worldwide since the 19th century. Over the past 200 years, many compounds from these two classes were isolated from natural sources, and most of them and their modified analogs possess significant bioactivities. Quinine and camptothecin are two of the most famous and important quinoline alkaloids, and their discoveries opened new areas in antimalarial and anticancer drug development, respectively. In this review, we survey the literature on bioactive alkaloids from these two classes and highlight research achievements prior to the year 2008 (Part I). Over 200 molecules with a broad range of bioactivities, including antitumor, antimalarial, antibacterial and antifungal, antiparasitic and insecticidal, antiviral, antiplatelet, anti-inflammatory, herbicidal, antioxidant and other activities, were reviewed. This survey should provide new clues or possibilities for the discovery of new and better drugs from the original naturally occurring quinoline and quinazoline alkaloids.

Antiulcer properties of fruits and vegetables: A mechanism based perspective

Gastric ulcer is the damage caused to mucosal layer of the stomach under the action of various factors like high levels of acid and pepsin, invasion by Helicobacter pylori, etc. Although most cases have been controlled and the rate of ulcer occurrence has reduced over the last few decades, gastric ulcer still holds a prime concern today. A range of palliative medicines comprising proton pump inhibitors, H2 receptor antagonists, COX-2 inhibitors (coxibs) is widely in use and patients have also been administered with acid suppression therapies. But these remedies aggravate the condition of patients causing severe side effects, or rather impart temporary relief. Therefore, it is highly imperative to develop safe and effective therapies for the treatment of gastric ulcer. Nature provides us various fruits and vegetables that can combat gastric ulcer through multiple mechanisms; predominantly via antioxidant, anti-inflammatory, antisecretory, antimicrobial, anticholinergic and cytoprotective activity, inhibition of small intestinal propulsion etc. Various phytochemicals from fruits and vegetables such as phenolics, flavonoids, tannins and saponins play a vital role in the prevention and cure of gastric ulcer. This review is a compendium of all fruits and vegetables known for their profound antiulcer effect and their underlying mechanisms of action.

Pharmacokinetics Studies of 12 Alkaloids in Rat Plasma after Oral Administration of Zuojin and Fan-Zuojin Formulas

Zuojin formula (ZJ) is a traditional Chinese medicine (TCM) prescription consisted of Coptidis Rhizoma (CR) and Euodiae Fructus (EF), and has been used to treat gastrointestinal (GI) disease for more than 700 years. Fan-Zuojin formula (FZJ) is a related TCM prescription also consisted of CR and EF with the opposite proportion. In recent years, ZJ was getting more attention for its antitumor potential, but the indeterminate pharmacokinetic (PK) behavior restricted its clinical applications, and the PK differences between ZJ and FZJ were also largely unknown. Consequently it is necessary to carry out a full-scale PK study to demonstrate the physiological disposition of ZJ, as well as the comparative PK study between ZJ and FZJ to illustrate the compatibility dose effects. Therefore a liquid chromatographic–tandem mass spectrometry (LC–MS/MS) method was established and validated for the determinations of coptisine, epiberberine, palmatine, berberine, 8-oxocoptisine, 8-oxoepiberberine, noroxyhydrastinine, corydaldine, dehydroevodiamine, evodiamine, wuchuyuamide-I, and evocarpine in rat plasma. PK characteristics of 12 alkaloids after oral administration of ZJ and FZJ were compared, and the result was analyzed and discussed with the help of an in silico study. Then an integrated PK study was carried out with the AUC-based weighting method and the total drug concentration method. The established method has been successfully applied to reveal the PK profiles of the 12 alkaloids in rat plasma after oral administration of ZJ and FZJ. The results showed that: (1) double peaks were observed in the plasma concentration-time (C–T) curves of the alkaloids after ZJ administration; but the C–T curves approximately matched the two-compartment model after FZJ administration; (2) There were wide variations in the absorption levels of these alkaloids; and even for a certain alkaloid, the dose modified systemic exposure levels and elimination rate also varied significantly after administration of ZJ and FZJ extracts. The results could be interpreted as follows: firstly, inhibition effect on GI motility caused by the high content CR alkaloids (especially berberine) in ZJ could delay the T_max, and increase the absorption and systemic exposure levels of the other alkaloids, and also lead to the double peak phenomenon of these alkaloids. However, for quaternary protoberberine alkaloids (QPA), double peaks were primarily caused by the different Ka value in two intestinal absorption sites; Secondly, absorption was the major obstacle to the systemic exposure level of the alkaloids from CR and EF. In silico and PK studies suggested that the absorption of these alkaloids, except QPAs, mainly depended on their solubility rather than permeability; Thirdly, EF could promote the absorption and accelerate the elimination of QPAs, and had a greater influence on the former than the latter. At last the integrated PK analysis suggested that berberine and dehydroevodiamine could be regarded as the representative components to reflect the PK behaviors of CR and EF alkaloids after administration of ZJ and FZJ. In conclusion, the absorption, elimination and systemic exposure level of these alkaloids were mainly influenced by the proportion of EF and CR, the pharmacological effect on GI motility, and the physicochemical property of these alkaloids. These findings would be helpful for a better understanding of the activities and clinical applications of ZJ, FZJ and other related TCM prescriptions.

Understanding the Molecular Mechanisms of the Interplay Between Herbal Medicines and Gut Microbiota

Herbal medicines (HMs) are much appreciated for their significant contribution to human survival and reproduction by remedial and prophylactic management of diseases. Defining the scientific basis of HMs will substantiate their value and promote their modernization. Ever-increasing evidence suggests that gut microbiota plays a crucial role in HM therapy by complicated interplay with HM components. This interplay includes such activities as: gut microbiota biotransforming HM chemicals into metabolites that harbor different bioavailability and bioactivity/toxicity from their precursors; HM chemicals improving the composition of gut microbiota, consequently ameliorating its dysfunction as well as associated pathological conditions; and gut microbiota mediating the interactions (synergistic and antagonistic) between the multiple chemicals in HMs. More advanced experimental designs are recommended for future study, such as overall chemical characterization of gut microbiota-metabolized HMs, direct microbial analysis of HM-targeted gut microbiota, and precise gut microbiota research model development. The outcomes of such research can further elucidate the interactions between HMs and gut microbiota, thereby opening a new window for defining the scientific basis of HMs and for guiding HM-based drug discovery.

Divergent Synthesis of Quinolone Natural Products from Pseudonocardia sp. CL38489

Two divergent synthetic routes are reported offering access to four quinolone natural products from Pseudonocardia sp. CL38489. Key steps to the natural products involved a regioselective epoxidation, an intramolecular Buchwald-Hartwig amination and a final acid-catalysed 1,3-allylic-alcohol rearrangement to give two of the natural products in one step. This study completes the synthesis of all eight antibacterial quinolone natural products reported in the family. In addition, this modular strategy enables an improved synthesis towards two natural products previously reported.

Development and validation of an UPLC-ESI-MS/MS method for determination of dehydroevodiamine, limonin, evodiamine, and rutaecarpine in Evodiae Fructus

Objective:

Evodiae Fructus (EF), one of the most widely used traditional Chinese medicines, mainly consists of alkaloids, is widely used for the treatments of headache and gastrointestinal disorders. In this study, a sensitive and reliable UPLC-ESI-MS/MS method was developed for qualitative determination of dehydroevodiamine, limonin, evodiamine, and rutaecarpine.

Materials and Methods:

Chromatographic separations were accomplished on a Phenomenex Kinetex XB-C18 column (2.1 × 150 mm, 1.7 μm) by using a gradient elution profile with a mobile phase consisting of 0.5% formic acid in water (A) and acetonitrile (B). Detection was performed using multiple reactions monitoring mode under ESI in the positive ion mode.

Results:

The results showed good linearity over the investigated concentration ranges (R²>0.9900) for the analytes. The limit of quantitations (LOQs) were 6.88 ng/mL for dehydroevodiamine, 18.6 ng/mL for limonin, 6.24 ng/mL for evodiamine, and 2.56 ng/mL for rutaecarpine, respectively. Intraday and interday precisions (relative standard deviations, %) were <5% and accuracies ranged from 92% to 106%.

Conclusion:

The validated method was successfully applied to assay the contents of the four compounds in EF samples from different regions, with which just 10 min was needed to analyze each sample.

Simultaneous Quantification of Limonin, Two Indolequinazoline Alkaloids, and Four Quinolone Alkaloids in Evodia rutaecarpa (Juss.) Benth by HPLC-DAD Method

A simple and efficient HPLC-DAD (225 nm) method was developed and validated for the simultaneous determination of limonin and six key alkaloids (evodiamine, rutaecarpine, 1-methyl-2-undecyl-4(1H)-quinolone, evocarpine, 1-methy-2-[(6Z,9Z)]-6,9-pentadecadienyl-4-(1H)-quinolone, and dihydroevocarpine) in Evodia rutaecarpa (Juss.) Benth, which has been widely used as one of the Traditional Chinese Medicines. The chromatographic separation was carried out on a Hypersil BDS C18 column, and gradient elution was employed with a mobile phase containing acetonitrile and water. Contents of the analytes in 18 batches of samples were analyzed by ultrasonic extraction with ethanol and water mixture (80 : 20, v/v) followed by HPLC analysis. Separation of the seven analytes was achieved within 60 min with good linearity (r > 0.999). The RSD of both the intraday and interday precision was below 1.85%. The accuracy at different concentrations was within the range of 97.91 to 100.49%. Hierarchical clustering analysis was performed to differentiate and classify the samples based on the contents of the seven constituents. This study indicated that the quality control of E. rutaecarpa could be simplified to the measurement of four constituents, and that limonin, 1-methyl-2-undecyl-4(1H)-quinolone, and dihydroevocarpine should also be served as the chemical markers together with evodiamine for the quality control of Evodia rutaecarpa (Juss.) Benth.

Quinolone alkaloids with antibacterial and cytotoxic activities from the fruits of Evodia rutaecarpa

Five new quinolone alkaloids, euocarpines A-E (16-20), four new natural products (1, 4, 12, and 14), and eleven known natural products were isolated from the fruits of Evodia rutaecarpa (Juss.) Benth. The structures of the new compounds were elucidated based on spectroscopic evidence. All compounds were evaluated for their antibacterial activity against three strains and for their cytotoxic activity against four human tumor cell lines. The results revealed that 5, 7-11, 13, 14, and 16-20 exhibited moderate antibacterial activities (MIC values: 4-128 μg/mL), and 9, 11, 14, and 17 exhibited moderate cytotoxic activities against HepG-2, Hela, BEL7402, and BEL7403 (IC50 values: 15.85-56.36 μM).

Kampo medicines for gastrointestinal tract disorders: a review of basic science and clinical evidence and their future application

Treatment with kampo, the Japanese traditional medicine, is a form of pharmacological therapy that combines modern Western and traditional Asian medical practices. In Japan, various traditional medicines are often combined with Western medicines and prescribed for patients with diseases such as gastroesophageal reflux disease, functional dyspepsia, chronic gastritis, irritable bowel syndrome, and post-operative ileus. Based on numerous past observations, Japanese traditional medicines are thought to be particularly useful in the treatment of medically unexplained physical symptoms such as nausea, abdominal discomfort, and anorexia. However, the detailed mechanism by which they mediate their pharmacological action is yet unknown. In addition, the clinical evidence to support their use is insufficient. This review focuses on the basic evidence of the pharmacological action and the clinical efficacies of kampo medicines accumulated over several past decades. In addition, we introduce both the current novel insights into kampo medicines and the therapeutic approach employed when they are used to treat various disorders of the gastrointestinal tract.

Pharmacological actions of multi-target-directed evodiamine

Evodiamine, a naturally occurring indole alkaloid, is one of the main bioactive ingredients of Evodiae fructus. With respect to the pharmacological actions of evodiamine, more attention has been paid to beneficial effects in insults involving cancer, obesity, nociception, inflammation, cardiovascular diseases, Alzheimer's disease, infectious diseases and themoregulative effects. evodiamine has evolved a superior ability to bind various proteins, so we also argue that it is good starting point for multi-target drugs. This review is primarily addressed to the description of the recent advances in the biological activity studies of evodiamine, with a focus on pharmacological mechanism. The present review also includes the pharmacokinetics and the detailed exploration of target-binding properties of evodiamine in an attempt to provide a direction for further multi-target drug design.

Alternative therapies for Helicobacter pylori: probiotics and phytomedicine

Helicobacter pylori is a common human pathogen infecting about 30% of children and 60% of adults worldwide and is responsible for diseases such as gastritis, peptic ulcer and gastric cancer. Treatment against H. pylori is based on the use of antibiotics, but therapy failure can be higher than 20% and is essentially due to an increase in the prevalence of antibiotic-resistant bacteria, which has led to the search for alternative therapies. In this review, we discuss alternative therapies for H. pylori, mainly phytotherapy and probiotics. Probiotics are live organisms or produced substances that are orally administrated, usually in addition to conventional antibiotic therapy. They may modulate the human microbiota and promote health, prevent antibiotic side effects, stimulate the immune response and directly compete with pathogenic bacteria. Phytomedicine consists of the use of plant extracts as medicines or health-promoting agents, but in most cases the molecular mode of action of the active ingredients of these herbal extracts is unknown. Possible mechanisms include inhibition of H. pylori urease enzyme, disruption of bacterial cell membrane, and modulation of the host immune system. Other alternative therapies are also reviewed.

Quinolones: from antibiotics to autoinducers

Since quinine was first isolated, animals, plants and microorganisms producing a wide variety of quinolone compounds have been discovered, several of which possess medicinally interesting properties ranging from antiallergenic and anticancer to antimicrobial activities. Over the years, these have served in the development of many synthetic drugs, including the successful fluoroquinolone antibiotics. Pseudomonas aeruginosa and related bacteria produce a number of 2-alkyl-4(1H)-quinolones, some of which exhibit antimicrobial activity. However, quinolones such as the Pseudomonas quinolone signal and 2-heptyl-4-hydroxyquinoline act as quorum-sensing signal molecules, controlling the expression of many virulence genes as a function of cell population density. Here, we review selectively this extensive family of bicyclic compounds, from natural and synthetic antimicrobials to signalling molecules, with a special emphasis on the biology of P. aeruginosa. In particular, we review their nomenclature and biochemistry, their multiple properties as membrane-interacting compounds, inhibitors of the cytochrome bc(1) complex and iron chelators, as well as the regulation of their biosynthesis and their integration into the intricate quorum-sensing regulatory networks governing virulence and secondary metabolite gene expression.

Anti-inflammatory and anti-infectious effects of Evodia rutaecarpa (Wuzhuyu) and its major bioactive components

This article reviews the anti-inflammatory relative and anti-infectious effects of Evodia rutaecarpa and its major bioactive components and the involvement of the nitric oxide synthases, cyclooxygenase, NADPH oxidase, nuclear factor kappa B, hypoxia-inducible factor 1 alpha, reactive oxygen species, prostaglandins, tumor necrosis factor, LIGHT, amyloid protein and orexigenic neuropeptides. Their potential applications for the treatment of endotoxaemia, obesity, diabetes, Alzheimer's disease and their uses as cardiovascular and gastrointestinal protective agents, analgesics, anti-oxidant, anti-atherosclerosis agents, dermatological agents and anti-infectious agents are highlighted. Stimulation of calcitonin gene-related peptide release may partially explain the analgesic, cardiovascular and gastrointestinal protective, anti-obese activities of Evodia rutaecarpa and its major bioactive components.

The Traditional Japanese Medicine Rikkunshito Promotes Gastric Emptying via the Antagonistic Action of the 5-HT(3) Receptor Pathway in Rats

The traditional Japanese medicine rikkunshito ameliorates the nitric oxide-associated delay in gastric emptying. Whether rikkunshito affects gastric motility associated with 5-hydroxytryptamine (serotonin: 5-HT) receptors or dopamine receptors is unknown. We examined the effects of rikkunshito on the delay in gastric emptying induced by 5-HT or dopamine using the phenol red method in male Wistar rats. 5-HT (0.01–1.0 mg kg⁻¹, i.p.) dose dependently delayed gastric emptying, similar to the effect of the 5-HT₃ receptor agonist 1-(3-chlorophenyl) biguanide (0.01–1.0 mg kg⁻¹, i.p.). Dopamine also dose dependently delayed gastric emptying. The 5-HT₃ receptor antagonist ondansetron (0.04–4.0 mg kg⁻¹) and rikkunshito (125–500 mg kg⁻¹) significantly suppressed the delay in gastric emptying caused by 5-HT or 1-(3-chlorophenyl) biguanide. Hesperidin (the most active ingredient in rikkunshito) suppressed the 5-HT-induced delayed gastric emptying in a dose-dependent manner, the maximum effect of which was similar to that of ondansetron (0.4 mg kg⁻¹). The improvement obtained by rikkunshito or ondansetron in delaying gastric emptying was completely blocked by pretreatment with atropine. Rikkunshito appears to improve delay in gastric emptying via the antagonistic action of the 5-HT₃ receptor pathway.

Determination of dehydroevodiamine in Evodia rutaecarpa (Juss.) Benth by high performance liquid chromatography and classification of the samples by using hierarchical clustering analysis

A simple, sensitive and accurate liquid chromatographic method with photodiode-array detection was developed for determination of dehydroevodiamine with detection wavelength at 368 nm and column temperature at 30 degrees C. The separation was carried out on an Agilent Zorbax SB-C(18) column (250 mm x 4.6 mm, 5 microm) together with a C(18) guard column. The mobile phase was acetonitrile-water (containing 30 mM sodium acetate trihydrate and 0.15% acetic acid) in the ratio of 30:70 (v/v) delivered at a flow rate of 1 mL/min. Excellent linear behavior was observed over the concentration range investigated, with correlation coefficient (R(2))=0.9998. This validated method was applied to determine the contents of dehydroevodiamine in 36 samples from different regions of China, and hierarchical clustering analysis was firstly used to classify and differentiate Evodia rutaecarpa samples. The analysis is specific and can be successfully applied to analyze E. rutaecarpa which is helpful for quality control of the herb.

Quality evaluation of Evodia rutaecarpa (Juss.) Benth by high performance liquid chromatography with photodiode-array detection

A simple, sensitive and accurate HPLC-DAD method was developed for simultaneous determination of wuchuyuamide-I, quercetin, limonin, evodiamine and rutaecarpine in Evodia rutaecarpa that has been widely used as one of the traditional Chinese medicines (TCMs). Chromatographic separations were performed on a reverse-phase C(18) column with the gradient elution of acetonitrile-water and the simultaneous detection at five wavelengths. Good linear behaviors over the investigated concentration ranges were observed with the values of r higher than 0.999 for all the analytes. The recoveries measured at three levels varied from 98.77 to 102.36%. The validated method was successfully applied for the simultaneous determination of the five chemical constituents in 36 batches of samples collected from different regions or time that were investigated and authenticated as E. rutaecarpa (Juss.) Benth. Hierarchical clustering analysis (HCA) and principal components analysis (PCA) were performed to differentiate and classify the samples based on the contents of the five characteristic constituents. The total contents of evodiamine and rutaecarpine in different samples were calculated and the blending method proposed was demonstrated to be very useful in saving resources and in guiding rational herb use.

Two new acylgluconic acids from the nearly ripe fruits of Evodia rutaecarpa

Two new acylgluconic acids, trans-feruloylgluconic acid (1) and trans-caffeoylgluconic acid (2), together with three known compounds, myo-inositol (3), phthalic acid dibutyl ester (4), and wuzhuyuamide-I (5), were isolated from the water soluble part of the dried nearly ripe fruits of Evodia rutaecarpa (Juss.) Benth. Their structures were determined by spectroscopic methods, including IR, UV, ESITOFMS, HRSIMS, 1D and 2D NMR spectral analyses.

Alkyl, aryl, alkylarylquinoline, and related alkaloids

The Rutaceae continues to be the primary source of new alkyl-, aryl-, and alkylarylquinolin/ones. In the past 17 years, the overall distribution of these alkaloid types within the family has changed little since the chemosystematics reviews by Waterman (270), Mester (40), and da Silva et al. (279). Alkylquinolones dominate the reported isolations with about 51% of the total, with arylquinolones (16%), alkylquinolines (15%), alkylarylquinolines (11%), arylquinolines (3%), alkylarylquinolones (2%), and quinolines (2%) as the significant structural groups contributing to the remainder of this class of alkaloids. The alkyl-, aryl-, and alkylarylquinolin/one alkaloids occur in 50 species belonging to 24 genera and 6 subfamilies. Despite the intensive chemical exploration of many species from other plants in the Rutales family, but not in the family Rutaceae, the first alkaloid alkylquinolone from a simaroubaceous plant (160) was not reported until 1997. Although many additional alkaloids have been reported, some of new structural types (Bo.4), substantial biosynthetic work on plant-derived alkylquinolin/ones has not yet been carried out. The biosynthesis of some of these alkaloids in bacteria was firmly established as being derived from anthranilic acid. Outside of the Rutales, alkyl-, aryl-, and alkylarylquinolin/ones have not been found, except for simple quinoline (A.1; only one) and 2-methylquinoline derivatives in the Zygophyllaceae, and only an atypical quinolone derivative (Ao.1) in the Asteraceae family. A few 3-phenylquinolines (2), 3-(1H-indol-3-yl)quinoline (1), and quinoline-quinazoline (1) alkaloids have been reported from only a single genus in the Zygophyllaceae. Tryptophan-derived quinolines in higher plants are confined to a few 2-carboxylicquinolin/ones (6) and 4-carbaldehydequinolines (5); the former found in the Ephedraceae (5), Boraginaceae (1), Fagaceae (1), Ginkgoaceae (1), Plumbaginaceae (1), Solanaceae (1), and Apiaceae (1), and the latter in the Moraceae (3), Alliaceae (1), and Pontederiacae (1). The number of quinolones derived from glycine and a polyketide is also limited. 5-Alkyl-2-methylquinolin-4(1H)-ones (8) occur in the Euphorbiaceae, and 5-alkyaryl-2-methylquinolin-4(1H)-ones ((3) in the Sterculiaceae. Alkylquinolin/ones are well-known as typical alkaloids of three Proteobacteria and three Actinobacteria; the genus Pseudomonas yielded the majority (46%) of the total number of alkaloids reported (39). 2-Carboxylicquinolin/ones (4) and 4-carbaldehydequinolines (6) are minor constituents in both divisions of bacteria. More interesting are the quinolactacins (7), in which the second nitrogen is derived from L-valine or L-isoleucine, recently reported to occur only in the fungus Penicillium. Many of these diverse alkaloids have served directly as medicines or as lead compounds for the synthesis (258) of derivatives with an improved biological profile. It is apparent from the summary view of the alkyl-, aryl-, and alkylarylquinolin/ones reported in the Rutaceae that they help to confirm the affinity between Rutoideae tribes and provide firm support for placing the Spathelioideae and the Dictyolomatoideae close to the more primitive Zanthoxyleae tribe. On the other hand, the bacteria and fungi are needed for more substantial chemical studies. When more data become available, it is likely that useful systematic correlations will emerge. More detailed studies regarding the biosynthetic pathways of the alkyl-, aryl-, and alkylarylquinolin/ones in the Rutaceae and in bacteria are needed. Such studies would clarify the differences in the pathways based on their derivation from anthranilic acid in bacteria and in rutaceous plants. Finally, this survey indicates that the Rutaceae, and various bacterial and fungal species offer considerable potential for the discovery of new or known alkaloids with significant and possibly valuable biological activities.

Quinolone alkaloids from evodiae fructus and their inhibitory effects on monoamine oxidase

1-Methyl-2-undecyl-4(1H)-quinolone (1) was previously isolated as a selective MAO-B inhibitor from the Evodiae Fructus. Further bioassay-guided purification led to the identification of five known quinolone alkaloids, 1-methyl-2-nonyl-4(1H)-quinolone (2), 1-methyl-2-[(Z)-6-undecenyl]-4(1H)-quinolone (3), evocarpine (4), 1-methyl-2-[(6Z,9Z)-6,9-pentadecadienyl]-4(1H)-quinolone (5), and dihydroevocarpine (6). All the isolates showed more potent inhibitory effects against MAO-B compared to MAO-A. The most MAO-B selective compound 5 among the isolates inhibited MAO-B in a competitive manner, according to kinetic analyses by Lineweaver-Burk reciprocal plots.

Anti-TB activity of Evodia elleryana bark extract

An ethyl acetate extract of bark from Evodia elleryana produced significant growth inhibition of Mycobacterium tuberculosis at concentrations only minimally inhibitory to human T cells. The crude extract yielded 95% inhibition of TB at 50 microg/ml. The crude extract yielded 29% growth inhibition of human T-cells in culture at that concentration.