Design, Synthesis, and Antifungal Activity of Novel Chalcone Derivatives Containing a Piperazine Fragment

In an attempt to find the biorational pesticides, 20 novel chalcone derivatives containing a piperazine fragment were designed and synthesized. Their fungicidal activities and preliminarily action mechanism against Rhizoctonia solani were evaluated. Strikingly, the biological activity of compound D2 was obtained by optimizing the structure of the system. Subsequently, the practical value of compound D2 was ascertained by the relative surveys on in vivo anti-R. solani and anti-Colletotrichum gloeosporioides. The results revealed by scanning electron microscopy demonstrated that compound D2 could induce irregular and shrivelled growth of mycelium and rupture of the mycelium surface. This study indicates that chalcone derivatives containing a piperazine skeleton had better inhibitory effect on plant fungi, providing further complementary research on new pesticides.

Synthesis, Characterization and Biomedical Application of Silver Nanoparticles

Silver nanoparticles (AgNPs) have been employed in various fields of biotechnology due to their proven properties as an antibacterial, antiviral and antifungal agent. AgNPs are generally synthesized through chemical, physical and biological approaches involving a myriad of methods. As each approach confers unique advantages and challenges, a trends analysis of literature for the AgNPs synthesis using different types of synthesis were also reviewed through a bibliometric approach. A sum of 10,278 publications were analyzed on the annual numbers of publication relating to AgNPs and biological, chemical or physical synthesis from 2010 to 2020 using Microsoft Excel applied to the Scopus publication database. Furthermore, another bibliometric clustering and mapping software were used to study the occurrences of author keywords on the biomedical applications of biosynthesized AgNPs and a total collection of 224 documents were found, sourced from articles, reviews, book chapters, conference papers and reviews. AgNPs provides an excellent, dependable, and effective solution for seven major concerns: as antibacterial, antiviral, anticancer, bone healing, bone cement, dental applications and wound healing. In recent years, AgNPs have been employed in biomedical sector due to their antibacterial, antiviral and anticancer properties. This review discussed on the types of synthesis, how AgNPs are characterized and their applications in biomedical field.

A review on processing methods and functions of wheat germ-derived bioactive peptides

Wheat germ protein is a potential resource to produce bioactive peptides. As a cheap, safe, and healthy nutritional factor, wheat germ-derived bioactive peptides (WGBPs) provide benefits and great potential for biomedical applications. The objective of this review is to reveal the current research status of WGBPs, including their preparation methods and biological functions, such as antibacterial, anti-tumor, immune regulation, antioxidant, and anti-inflammatory properties, etc. We also reviewed the information in terms of the preventive ability of WGBPs to treat serious infectious diseases, to offer their reference to further research and application. Opinions on future research directions are also discussed. Through the review of previous research, we find that there are still some scientific issues in the basic research and industrialization process of WGBPs that deserve further exploration. Firstly, based on current complex enzymolysis, the preparation and production of WGBPs need to be combined with other advanced technology to achieve efficient and large-scale production. Secondly, studies on the bioavailability, biosafety, and mechanism against different diseases of WGBPs need to be carried out in different in vitro and in vivo models. More human experimental evidence is also required to support its industrial application as a functional food and nutritional supplement.HighlightsThe purification and identification of wheat germ-derived bioactive peptides.The main biological activities and potential mechanisms of wheat germ hydrolysates/peptides.Possible absorption and transport pathways of wheat germ hydrolysate/peptide.Wheat germ peptide shows a variety of health benefits according to its amino acid sequence.Current food applications and future perspectives of wheat germ protein hydrolysates/peptide.

Study on the mechanism of ErtongKe granules in the treatment of cough using network pharmacology and molecular docking technology

BACKGROUND

The etiology and pathogenesis of cough are complex. As a Chinese patent medicine that has been on the market, ErtongKe (ETK) granules have a good effect in treating acute and chronic cough in children. The purpose of this research was to determine the bioactive components and possible action mechanisms of ETK in the treatment of cough using an integrated network pharmacology method.

METHODS

The Traditional Chinese Medicine Systems Pharmacology (TCMSP) and Swiss target prediction databases were used to screen the potential components and associated targets of ETK. The Genecards database was then used to gather targets interacting with cough. An analysis of the signaling pathways associated with ETK for cough treatment was carried out using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) enrichment analysis methods. Cytoscape 3.8.1 was used to design the protein-protein interaction (PPI) and compound-target-pathway networks. Finally, the important genes and active components of ETK were confirmed using Auto Dock vina and Discovery studio software.

RESULTS

Total 242 active components of ETK were screened, 1,173 potential targets related to the ingredients and 4,400 targets related to cough were collected separately. Moreover, 600 candidate targets and 39 signaling pathways were determined. We also screened out the following core components, including tuberostemonone, quercetin, kaempferol, praeruptorin E, stigmasterol, oroxylin A, and other potentially active ingredients. At the same time, 8 core targets, including JUN, PIK3CA, PIK3R1, MAPK14, EGFR, SRC, AKT1, and MAPK1, and 20 key pathways, including the cAMP signaling pathway, calcium signaling pathway, and PI3K-Akt signaling pathway among others, were also selected. All the 8 core targets were verified by molecular docking.

CONCLUSIONS

This research established that ETK exerts anti-cough activity by modulating several targets and pathways through multiple components. Additionally, the pooled results shed light on ETK compounds being investigated as potential antitussives.

Analysis of role of rat cerebral pericytes in cerebral vasospasm after subarachnoid hemorrhage and molecular mechanism of neurovascular injury

To investigate mechanism of pericytes in the early stage of subarachnoid haemorrhage (SAH) and its associated microvascular spasm and neurovascular injury, 100 healthy 8-week-old Sprague-Dawley male rats were taken as subjects and divided into four groups: group A (sham operation, control group), group B (SAH operation group), group C (SAH operation group treated with scutellarin), and group D (SAH operation group treated with L-nitro-arginine). 72 hours after the operation, the rats were conducted assessment of neurological impairment, observation of microangiography, detection of blood-brain barrier permeability, observation of skull base haemorrhage, identification of pericyte culture, and measurement of blood nitric oxide. The results showed that neurological impairment score, degree of micro-vasoconstriction, and BBB permeability of group C were significantly better than those of group B and D (P<0.05), there was no significant difference between group C and group A (P>0.05). There were significantly fewer blood clots in the brain of group C, and the order of expression levels of α-smooth muscle actin (α-SMA) in perioperative cells of the four groups from highest to lowest were D, B, C, and A. Nitric oxide concentration inhibited expression of α-SMA in pericytes after SAH at both protein and mRNA levels. The detection results of nitric oxide in the blood of four groups of rats confirmed that pericyte phenotype conversion and actin α-SMA expression could be prevented by upregulation of nitric oxide in serum, so as to relieve pathological symptoms after SAH operation.

Discovery of zeylenone from Uvaria grandiflora as a potential botanical fungicide

BACKGROUND

Botanical pesticides play an important role in organic agricultural practices and are widely used in integrated pest management (IPM). Uvaria grandiflora was mainly reported as traditional medicines and possessed antibacterial, antioxidant, and antiprotozoal activities. Therefore, important biological activities of U. grandiflora may suggest that they have the potential to be used as botanical pesticides.

RESULTS

The extract of U. grandiflora exhibited broad-spectrum inhibitory activity toward phytopathogenic fungi and oomycetes, particularly against Colletotrichum musae and Phytophthora capsici, and its secondary metabolite zeylenone also displayed strong antifungal and anti-oomycete activities against phytopathogens. Particularly, half maximal effective concentration (EC₅₀ ) values of zeylenone against Phytophthora capsici and C. musae were 6.98 and 3.37 μg mL^-1 , showing better inhibitory effects than those of commercial fungicides (azoxystrobin and osthole). Additionally, the pot experiments showed that the extract of U. grandiflora could effectively control Pseudoperonospora cubensis, Phytophthora infestans, Phytophthora capsici and Podosphaera xanthii. In the field experiment, 5% microemulsion of U. grandiflora extract exhibited 79.72% efficacy against cucumber powdery mildew at 87.5 g ha^-1 on the 14th day after two sprayings, which was better than that of 21.5% trifloxystrobin and 21.5% fluopyram SC at 200.9 g ha^-1 . Surprisingly, 5% microemulsion of U. grandiflora extract could promote cucumber growth significantly. Furthermore, the action mechanism analysis indicated that zeylenone may damage the cytoderm and affect energy metabolism of Phytophthora capsici.

CONCLUSION

It is the first time that the extract of U. grandiflora and zeylenone have been discovered leading to broad application prospects in the development as botanical fungicides. © 2021 Society of Chemical Industry.

Integration of Transcriptomic and Proteomic Data Reveals the Possible Action Mechanism of the Antimicrobial Zhongshengmycin Against Didymella segeticola, the Causal Agent of Tea Leaf Spot

Tea leaf spot, caused by the fungal phytopathogen Didymella segeticola, is an important foliar disease that can cause huge losses in the production and quality of tea, and there are no effective management measures to control the disease. This study screened a natural antimicrobial chemical for its activity against D. segeticola and studied its mode of action. Antifungal activity of the Streptomyces-derived antimicrobial zhongshengmycin (ZSM) against D. segeticola strain GZSQ-4 was assayed in vitro via the mycelial growth rate method. Optical microscopy and scanning and transmission electron microscopy were used to observe the morphological effects on hyphae treated with ZSM, with these studies complemented by transcriptomic, proteomic, and bioinformatic studies to identify the differentially expressed genes or differentially expressed proteins in hyphae treated with ZSM. Correlation analysis of transcriptomic and proteomic data were used to reveal the mode of action. The results indicated that ZSM could inhibit the growth of hyphae in vitro with a half-maximal effective concentration of 5.9 μg/ml, inducing some morphological changes in organelles, septa, and extracellular polysaccharides, targeting ribosomes to disturb translation, affecting the biosynthesis of some hyphal proteins at the messenger RNA and protein levels, and revealing correlations between findings from transcriptomes and proteomes.

Light-dependent reactions of animal circadian photoreceptor cryptochrome

Circadian rhythms are endogenous autonomous 24-h oscillations that are generated by a transcription-translation feedback loop (TTFL). In the positive arm of the TTFL, two transcription factors activate the expression of two genes of the negative arm as well as circadian clock-regulated genes. The circadian clocks are reset through photoreceptor proteins by sunlight in the early morning to keep synchrony with the geological clock. Among animal circadian photoreceptors, Drosophila Cryptochrome (DmCRY) has some unique properties because Drosophila has a single cryptochrome (CRY) that appears to have functions which are specific to organs or tissues, or even to a subset of cells. In mammals, CRYs are not photoreceptors but function in the TTFL, while insects have a light-insensitive mammalian-like CRY or a Drosophila-like photoreceptor CRY (or both). Here, we postulate that as being just one CRY in Drosophila, DmCRY might play different roles in different tissues/organs in a context-dependent manner. In addition to being a circadian photoreceptor/protein, attributing also a magnetoreception function to DmCRY has increased its workload. Considering that DmCRY senses photons as a photoreceptor but also can regulate many different events in a light-dependent manner, differential protein-protein interactions (PPIs) of DmCRY might play a critical role in the generation of such diverse outputs. Therefore, we need to add novel approaches in addition to the current ones to study multiple and context-dependent functions of DmCRY by adopting recently developed techniques. Successful identification of transient/fast PPIs on a scale of minutes would enhance our understanding of light-dependent and/or magnetoreception-associated reactions.

An Investigation of Cutting Performance and Action Mechanism in Ultrasonic Vibration-Assisted Milling of Ti6Al4V Using a PCD Tool

A polycrystalline diamond (PCD) tool is employed in cutting various titanium alloys because of its excellent properties. However, improving the cutting performance of titanium alloys is still a challenge. Here, an experimental investigation on the influence of ultrasonic vibration-assisted machining (UVAM) of Ti6Al4V titanium alloy on the cutting performance and action mechanism was studied using a PCD tool. Cutting force, machined surface, surface adhesion, and wear morphology were analyzed. The results indicated that UVAM can effectively improve cutting performance. It was found that there was serious adhesion and wear of slight fragments close to the cutting edge after ultrasonic-assisted dry milling. Furthermore, the action mechanism of UVAM in improving cutting performance was discussed and analyzed from the perspective of intermittent cutting.

Chemical Structure and Anticoagulant Property of a Novel Sulfated Polysaccharide from the Green Alga Cladophora oligoclada

Marine macroalgae are efficient producers of sulfated polysaccharides. The algal sulfated polysaccharides possess diverse bioactivities and peculiar chemical structures, and represent a great potential source to be explored. In the present study, a heparinoid-active sulfated polysaccharide was isolated from the green alga Cladophora oligoclada. Results of chemical and spectroscopic analyses indicated that the sulfated polysaccharide was composed of →6)-β-d-Galp-(1→, β-d-Galp-(1→, →6)-α-d-Glcp-(1→ and →3)-β-d-Galp-(1→ units with sulfate esters at C-2/C-4 of →6)-β-d-Galp-(1→, C-6 of →3)-β-d-Galp-(1→ and C-3 of →6)-α-d-Glcp-(1→ units. The branches consisting of β-d-Galp-(1→ and →6)-β-d-Galp-(1→ units were located in C-3 of →6)-β-d-Galp-(1→ units. The sulfated polysaccharide exhibited potent anticoagulant activity in vitro and in vivo as evaluated by activated partial thromboplastin time (APTT), thrombin time, and the fibrinogen level. For the APTT, the signal for clotting time was more than 200 s at 100 μg/mL in vitro and at 15 mg/kg in vivo. The obvious thrombolytic activity of the sulfated polysaccharide in vitro was also found. The mechanism analysis of anticoagulant action demonstrated that the sulfated polysaccharide significantly inhibited the activities of all intrinsic coagulation factors, which were less than 1.0% at 50 μg/mL, but selectively inhibited common coagulation factors. Furthermore, the sulfated polysaccharide strongly stimulated the inhibition of thrombin by potentiating antithrombin-III (AT-III) or heparin cofactor-II, and it also largely promoted the inhibition of factor Xa mediated by AT-III. These results revealed that the sulfated polysaccharide from C. oligoclada had potential to become an anticoagulant agent for prevention and therapy of thrombotic diseases.

Systems Pharmacology-Based Dissection of Anti-Cancer Mechanism of Traditional Chinese Herb Saussurea involucrata

Cancer has the highest mortality in humans worldwide, and the development of effective drugs remains a key issue. Traditional Chinese medicine Saussurea involucrata (SI) exhibits a series of effects, such as anti-cancer, but the action mechanisms are still unclear. Here, systems pharmacology was applied to reveal its anti-cancer mechanism. First, we screened the active compounds of SI. Then, the compound–target network, target–disease network, and target–pathway network were constructed. DAVID was applied for GOBP analysis and KEGG pathway enrichment analysis on cancer-related targets. Seven potential compounds and 187 targets were identified. The target–disease classification network showed that compounds mainly regulated proteins related to cancer, nervous system diseases, and cardiovascular system diseases. Also, SI anti-tumor effect mainly associated with the regulation of NO production, angiogenesis, MAPK, and PKB from GOBP enrichment. Additionally, KEGG pathway enrichment indicated that targets involved in anti-inflammatory action, inhibiting angiogenesis and anti-proliferation or inducing apoptosis. Experimental validation showed that four active compounds could inhibit cell proliferation and promote apoptosis in A549 (except for kaempferol), PC-3, and C6 cells. This study not only provides experimental evidence for further research on SI in cancer treatment but also promotes the development of potential drugs of SI in modern medicine.

Pine Rosin as a Valuable Natural Resource in the Synthesis of Fungicide Candidates for Controlling Fusarium oxysporum on Cucumber

To improve the effect of pine rosin in plant fungicides, four series of dehydroabietyl-1,3,4-thiadiazole derivatives from the natural product rosin were synthesized. Based on the evaluation of the in vitro antifungal activity against Sclerotinia sclerotiorum, Botrytis cinerea, Fusarium oxysporum, and Magnaporthe oryzae, rosin-based 1,3,4-thiadiazole compounds containing thiophene heterocycles were screened. Notably, compound 3e [dehydroabietyl-(1,3,4-thiadiazol-2-yl)-5-nitrothiophene-2-carboxamide] exhibited excellent antifungal property against F. oxysporum with an EC₅₀ of 0.618 mg/L, which was lower than that of the positive control carbendazim (0.649 mg/L). The in vivo antifungal activity results showed that 3e exerted a protective effect on cucumber plants. Physiological and biochemical studies showed that the primary mechanism of action of compound 3e on F. oxysporum was it changed the mycelial morphology, increased the cell membrane permeability, and inhibited the synthesis of ergosterol in the mycelia. Furthermore, the quantitative structure-activity relationship studies revealed that the frontier orbital energy in the molecule had a key role in the antifungal activity through the conjugation and electrostatic interaction between compound 3e and the receptors of the target. Thus, the present study highlighted the application of rosin-based fungicidal candidates and exploited efficient plant pesticides for sustainable crop production.

Antibacterial Potential by Rupture Membrane and Antioxidant Capacity of Purified Phenolic Fractions of Persea americana Leaf Extract

The present research focused on evaluating the antibacterial effect and the mechanism of action of partially purified fractions of an extract of Persea americana. Furthermore, both its antioxidant capacity and composition were evaluated. The extract was fractionated by vacuum liquid chromatography. The antimicrobial effect against Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 11229), Pseudomonas aeruginosa (ATCC 15442), and Salmonella choleraesuis (ATCC 1070) was analyzed by microdilution and the mechanism of action by the Sytox green method. The antioxidant capacity was determined by DPPH, FRAP, and ABTS techniques and the composition by Rp-HPLC-MS. All fractions showed a concentration-dependent antibacterial effect. Fractions F3, F4, and F5 (1000 µg/mL) showed a better antibacterial effect than the extract against the bacteria mentioned. The F3 fraction showed inhibition of 95.43 ± 3.04% on S. aureus, F4 showed 93.30 ± 0.52% on E. coli, and F5 showed 88.63 ± 1.15% on S. choleraesuis and 86.46 ± 3.20% on P. aeruginosa. The most susceptible strain to the treatment with the extract was S. aureus. Therefore, in this strain, the bacterial membrane damage induced by the extract and fractions was evidenced by light fluorescence microscopy. Furthermore, the extract had better antioxidant action than each fraction. Finally, sinensitin was detected in F3 and cinnamoyl glucose, caffeoyl tartaric acid, and cyanidin 3-O-(6′′-malonyl-3′′-glucosyl-glucoside) were detected in F4; esculin and kaempferide, detected in F5, could be associated with the antibacterial and antioxidant effect.

Natural-Derived Polysaccharides From Plants, Mushrooms, and Seaweeds for the Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease impairing the gastrointestinal tract, and its incidence and prevalence have been increasing over time worldwide. IBD greatly reduces peoples' quality of life and results in several life-threatening complications, including polyp, toxic colonic dilatation, intestinal perforation, gastrointestinal bleeding, and cancerization. The current therapies for IBD mainly include drugs for noncritical patients and operation for critical patients. However, continuous use of these drugs causes serious side effects and increased drug resistance, and the demand of effective and affordable drugs with minimal side effects for IBD sufferers is urgent. Natural-derived polysaccharides are becoming a research hotspot for their therapeutic effects on IBD. This study focuses on the research progress of various natural polysaccharides from plants, seaweeds, and mushrooms for the treatment of IBD during recent 20 years. Regulation of oxidative stress, inflammatory status, gut microbiota, and immune system and protection of the intestinal epithelial barrier function are the underlying mechanisms for the natural-derived polysaccharides to treat IBD. The excellent efficacy and safety of polysaccharides make them promising candidates for IBD therapy.

Transcriptome Analysis on the Mechanism of Ethylicin Inhibiting Pseudomonas syringae pv. actinidiae on Kiwifruit

Bacterial canker disease caused by Pseudomonas syringae pv. actinidiae (Psa) is a devastating disease of kiwifruit, which is severely limiting the development of the kiwifruit industry. Ethylicin is a broad-spectrum plant biomimetic fungicide. However, its application in the control of kiwifruit bacterial canker is rarely reported, and the mechanism of ethylicin on Psa remains unknown. In this study, we investigated the effect of ethylicin on Psa in vitro and in vivo and found that ethylicin can inhibit the growth of Psa and prevent the cankering in the plant stem. Mechanism investigation indicated that ethylicin acted by limiting the movement of Psa, destroying the cell membrane of Psa, and inhibiting the formation of Psa biofilm. In addition, it was also found through transcriptomics research that ethylicin can up-regulate the expression of genes related to protein export and biofilm formation-Pseudomonas aeruginosa and down-regulate the expression of genes related to flagellar assembly in Psa. This study concluded that ethylicin can effectively inhibit Psa growth, and it could help to gain a better understanding of the mechanisms of ethylicin inhibiting Psa and provide practical data for the application of ethylicin as a highly potent agent for controlling the bacterial canker disease of kiwifruit.

The Antimicrobial Peptide Melectin Shows Both Antimicrobial and Antitumor Activity via Membrane Interference and DNA Binding

Purpose

Increasingly complex diseases require novel drugs for their treatment. Antimicrobial peptides (AMPs) are promising candidate treatments due to their broad existence and special characteristics. However, the current understanding of AMPs is not sufficient to allow them to be produced commercially for clinical use.

Materials and Methods

Melectin, from the venom of the cleptoparasitic bee Melecta albifrons, does not exhibit sequence homology with other wasp venom peptides. To investigate this more deeply, we explored the antibacterial and antitumor activities of Melectin and related mechanisms.

Results

Our results demonstrate that Melectin possesses antimicrobial properties against standard sensitive/clinical drug-resistant bacteria strains as well as antitumor activity. It has an α-helix form and exhibits moderate cytotoxicity. Its action mechanisms are involved with membrane interfering and DNA binding. The membrane interfering effect was distinct between different phospholipid compositions.

Conclusion

We found that Melectin may serve as a new potential template in the battle against multidrug resistance, and our study indicated that there are promising prospects for medically applicable drugs based on AMPs.

Transcriptomic, Biochemical, and Morphological Study Reveals the Mechanism of Inhibition of Pseudopestalotiopsis camelliae-sinensis by Phenazine-1-Carboxylic Acid

Gray blight disease is one of the most destructive diseases of tea plants and occurs widely in the tea-growing areas of the world. It is caused by several fungal phytopathogens, of which Pseudopestalotiopsis camelliae-sinensis is the main pathogen in China. The environmentally friendly antimicrobial, phenazine-1-carboxylic acid (PCA), a metabolite of the natural soil-borne bacteria Pseudomonas spp., can inhibit a range of fungal crop diseases. In this study, we determined that PCA was active against Ps. camelliae-sinensis in vitro. We studied the mode of action of PCA on hyphae using a microscopic investigation, transcriptomics, biochemical methods, and molecular docking. The results of scanning and transmission electron microscopy indicated that PCA caused developmental deformity of mycelia and organelle damage, and it significantly decreased the accumulation of exopolysaccharides on the hyphal surface. The transcriptome revealed that 1705 and 1683 differentially expressed genes of Ps. camelliae-sinensis treated with PCA were up-regulated or down-regulated, respectively, with genes associated with ribosome biogenesis, oxidative phosphorylation, and encoding various proteins of N-glycan biosynthesis being significantly up-regulated. Up-regulation of nine genes related to N-glycan biosynthesis of Ps. camelliae-sinensis in response to PCA treatment was confirmed by reverse transcription qPCR. The enzymatic activity of catalase and superoxide dismutase of hyphae was significantly decreased by PCA treatment. Our results indicated that exposure to PCA resulted in expression changes in oxidoreductase genes, accumulation of reactive oxygen species, and decreased activity of catalase, with concomitant damage to the fungal cell membrane and cell wall.

Deep Brain Stimulation for Alzheimer's Disease: Stimulation Parameters and Potential Mechanisms of Action

Deep brain stimulation (DBS) is a neurosurgical technique that regulates neuron activity by using internal pulse generators to electrodes in specific target areas of the brain. As a blind treatment, DBS is widely used in the field of mental and neurological diseases, although its mechanism of action is still unclear. In the past 10 years, DBS has shown a certain positive effect in animal models and patients with Alzheimer's disease (AD), but there are also different results that may be related to the stimulation parameters of DBS. Based on this, determining the optimal stimulation parameters for DBS in AD and understanding its mechanism of action are essential to promote the clinical application of DBS in AD. This review aims to explore the therapeutic effect of DBS in AD, and to analyze its stimulation parameters and potential mechanism of action. The keywords "Deep brain stimulation" and "Alzheimer's Disease" were used for systematic searches in the literature databases of Web of Science and PubMed (from 1900 to September 29, 2020). All human clinical studies and animal studies were reported in English, including individual case studies and long-term follow-up studies, were included. These studies described the therapeutic effects of DBS in AD. The results included 16 human clinical studies and 14 animal studies, of which 28 studies clearly demonstrated the positive effect of DBS in AD. We analyzed the current stimulation parameters of DBS in AD from stimulation target, stimulation frequency, stimulation start time, stimulation duration, unilateral/bilateral treatment and current intensity, etc., and we also discussed its potential mechanism of action from multiple aspects, including regulating related neural networks, promoting nerve oscillation, reducing β-amyloid and tau levels, reducing neuroinflammation, regulating the cholinergic system, inducing the synthesis of nerve growth factor.

[Needle-embedding treatment for hemifacial spasm: research progress]

The articles regarding needle-embedding treatment for hemifacial spasm published before September 30, 2019 were searched from SinoMed, Wanfang, CNKI, VIP and PubMed database, and were analyzed and summarized from treatment methods, acupoint selection, stage differentiation and action mechanism. As a result, 45 Chinese articles were obtained. The needle-embedding treatment was divided into intradermal needling and acupoint thread-embedding; the top five acupoints were Sibai (ST 2), Taiyang (EX-HN 5), Dicang (ST 4), Jiache (ST 6) and spasm trigger points. The basic research of needle-embedding treatment for hemifacial spasm is weak, and the literature regarding stage differentiation is insufficient, which are in need of further study.

Preparation of a functional yogurt with Ligustrum robustum (Rxob.) Blume and its action mechanism

A functional yogurt was prepared with Ligustrum robustum (Rxob.) Blume extract (LRE), while its antioxidant and hypoglycemic activities were evaluated and its action mechanism was further explored. With the cofermentation of LRE, the yogurt showed the fine quality characteristics, including pH, titratable acidity, texture, syneresis susceptibility, color, microbiological content, and chemical composition. Meanwhile, the yogurt exhibited the remarkable antioxidant capability to enhance the activities of antioxidant enzymes and reduce the malondialdehyde level in animal serums. In addition, the yogurt showed the obvious hypoglycemic activity to inhibit the decrease of glucose tolerance and the increase of postprandial hyperglycemia of diabetes mice. Furthermore, using the analysis of molecular docking, the main compounds of LRE could combine tightly with α-amylase and α-glucosidase by hydrogen bond and hydrophobic interaction, so as to change their spatial structure and inhibit their biocatalytic activity in glucose metabolism. All present results suggested that LRE showed the potential value to be used as supplement to enhance the quality and functions of yogurt in food industry. PRACTICAL APPLICATION: The hypoglycemic and antioxidant activities of a functional yogurt cofermented with LRE were found and its relative action mechanism was also explored. This work provide the experimental and theoretical basis for the application of this yogurt as nutraceuticals to protect human health in food industry.

[Effect of Biochar on Soil Enzyme Activity & the Bacterial Community and Its Mechanism]

Biochar-based fertilizers can improve the mineralization of carbon and nitrogen in soil and enhance the soil micro-ecological environment due to particular physical and chemical properties. It is of great significance to explore the underlying mechanism of biochar-based fertilizer in the regulation of soil microorganisms and soil enzyme activity to improve soil quality. Field experiments were conducted to investigate the effects of different biochar-based fertilizer rates[0 (CK2), 0.6 (T1), 0.9 (T2), 1.2 (T3), and 1.5 (T4) t·hm^-2]on soil nutrients, soil enzyme activity, and bacterial community structure. The results showed that with the application of biochar-based fertilizer, soil bulk density decreased, while the pH value, available P, available K, organic matter content, and the C/N ratio increased by 0.32%-5.83%, 14.09%-23.16%, 0%-38.70%, 7.49%-14.16%, and 4.06%-10.13%, respectively, compared to that of the CK2 treatment. With increasing rates of biochar-based fertilizer, the enzyme activity first increased and then decreased. Invertase (INV), urease (URE), catalase (CAT), and neutral phosphatase (NPH) activity under the application of biochar-based fertilizer were 63.73%-166.37%, 117.52%-174.03%, 12.98%-23.59%, and 60.84%-119.71% higher than that of CK2, respectively. The corresponding bacterial diversity was significantly improved, especially with regard to the increase in the abundance of growth promoting bacteria, such as Gemmatimonadetes and Proteobacteria, and decreased the abundance of Acidobacteria and Actinobacteria. The correlation analysis showed that soil C/N ratio was the key factor affecting soil enzyme activity, and there was a significant positive correlation between soil enzyme activity and bacterial diversity. There were significantly positive correlations among the activities of the above four soil enzymes and the relative abundance of Gemmatimonadetes (P<0.01), with CAT being the key factor affecting the bacterial community structure. This study revealed a relationship between soil enzyme activity and microbial colonies, which provides a theoretical basis and mechanism for applying biochar to regulate the soil enzyme and micro-ecological environment.

Multifunctional Role of Polyvinylpyrrolidone in Pharmaceutical Formulations

Polyvinylpyrrolidone (PVP), a non-ionic polymer, has been employed in multifarious fields such as paper, fibers and textiles, ceramics, and pharmaceutics due to its superior properties. Especially in pharmacy, the properties of inertness, non-toxicity, and biocompatibility make it a versatile excipient for both conventional formulations and novel controlled or targeted delivery systems, serving as a binder, coating agent, suspending agent, pore-former, solubilizer, stabilizer, etc. PVP with different molecular weights (MWs) and concentrations is used in a variety of formulations for different purposes. In this review, PVP-related researches mainly in recent 10 years were collected, and its main pharmaceutical applications were summarized as follows: (i) improving the bioavailability and stability of drugs, (ii) improving the physicomechanical properties of preparations, (iii) adjusting the release rate of drugs, and (iv) prolonging the in vivo circulation time of liposomes. Most of these applications could be explained by the viscosity, solubility, hydrophilicity, and hydrogen bond-forming ability of PVP, and the specific action mechanisms for each application were also tried to figure out. The effect of PVP on bioavailability improvement establishes it as a promising polymer in the emerging controlled or targeted formulations, attracting growing interest on it. Therefore, given its irreplaceability and tremendous opportunities for future developments, this review aims to provide an informative reference about current roles of PVP in pharmacy for interested readers.

[Mechanism and experimental verification of Sijunzi Decoction in treatment of ulcerative colitis based on network pharmacology]

To explore the mechanism of Sijunzi Decoction in the treatment of ulcerative colitis(UC) based on network pharmacology. The active components and corresponding targets of Sijunzi Decoction were extracted with Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP), and the targets were standardized with the help of Uniprot database. The related targets of UC were obtained through GeneCards database and Disgenet database, and the intersection targets of drugs and diseases were screened by R language. The visual regulation network of &quot;active ingredient-disease target&quot; of Sijunzi Decoction was constructed by Cytoscape software, and the protein-protein interaction network was constructed by STRING database. The functional enrichment analysis of gene ontology(GO) and the enrichment analysis of Kyoto encyclopedia of genes and genomes(KEGG) pathway were carried out on Bioconductor platform, and some of the targets were verified by animal experiments. Through database analysis, a total of 135 active components of Sijunzi Decoction, 114 predicted targets and 80 common targets with UC were obtained. The core target proteins included interleukin 6(IL-6), caspase-3(CASP3), vascular endothelial growth factor A(VEGFA), epidermal growth factor receptor(EGFR) and so on. GO functional enrichment analysis involved 102 items, which mainly affected transcription factor activity, enzyme activity, receptor activity and biochemical process regulation. KEGG pathway enrichment analysis showed that 120 items were involved in human cytomegalovirus infection, cancer, apoptosis, inflammation and other pathways. Mouse experiments showed that Sijunzi Decoction could down-regulate the expression of target proteins IL-6 and caspase-3 and inhibit intestinal epithelial cell apoptosis. The treatment of UC with Sijunzi Decoction is the result of the interaction among multi-components, multi-targets and multi-pathways. It is proved by experiments that Sijunzi Decoction may play an effective role by regulating the expression of IL-6 and caspase-3, and getting involved in apoptosis, inflammation and other pathways.

Targeted and Intracellular Antibacterial Activity against S. agalactiae of the Chimeric Peptides Based on Pheromone and Cell-Penetrating Peptides

The significance of the complex bacterial ecosystem in the human body and the impediment of the mammalian membrane against many antibiotics together emphasize the necessity to develop antimicrobial agents with precise antimicrobial and cell-penetrating activities. A simple and feasible method for generating dual-function antimicrobial peptides inspired by highly hydrophobic peptide pheromone and cationic cell-penetrating peptides is presented. Furthermore, the extension of the peptide candidate library is achieved by modifying the charged domain. The bacteria-selective peptides L1, L2, L10, and L11 kill Streptococcus agalactiae by disrupting the membrane structure, and the targeted mechanism is suggested where the peptides offset the entrapment of S. agalactiae rather than of other bacteria. Moreover, L2 and L10 possess intracellular antibacterial activity and carrier property, which is mainly dependent on endocytosis. Given their suitable biocompatibility, high tolerance, no drug resistance, and effective antimicrobial capacity in a mouse mastitis model, L2 and L10 can be powerful weapons against S. agalactiae pathogen infection.

Integrated Network Pharmacology Analysis and Experimental Validation to Reveal the Mechanism of Anti-Insulin Resistance Effects of Moringa oleifera Seeds

Background and Purpose

Insulin resistance (IR) is one of the factors that results in metabolic syndrome, type 2 diabetes mellitus and different aspects of cardiovascular diseases. Moringa oleifera seeds (MOS), traditionally used as an antidiabetic food and traditional medicine in tropical Asia and Africa, have exhibited potential effects in improving IR. To systematically explore the pharmacological mechanism of the anti-IR effects of MOS, we adopted a network pharmacology approach at the molecular level.

Methods

By incorporating compound screening and target prediction, a feasible compound-target-pathway network pharmacology model was established to systematically predict the potential active components and mechanisms of the anti-IR effects of MOS. Biological methods were then used to verify the results of the network pharmacology analysis.

Results

Our comprehensive systematic approach successfully identified 32 bioactive compounds in MOS and 44 potential targets of these compounds related to IR, as well as 37 potential pathways related to IR. Moreover, the network pharmacology analysis revealed that glycosidic isothiocyanates and glycosidic benzylamines were the major active components that improved IR by acting on key targets, such as SRC, PTPN1, and CASP3, which were involved in inflammatory responses and insulin-related pathways. Further biological research demonstrated that the anti-IR effects of MOS were mediated by increasing glucose uptake and modulating the expression of SRC and PTPN1.

Conclusion

Our study successfully predicts the active ingredients and potential targets of MOS for improving IR and helps to illustrate mechanism of action at a systemic level. This study not only provides new insights into the chemical basis and pharmacology of MOS but also demonstrates a feasible method for discovering potential drugs from traditional medicines.

Jaburetox, a urease-derived peptide: Effects on enzymatic pathways of the cockroach Nauphoeta cinerea

Jaburetox is a recombinant peptide derived from one of the Canavalia ensiformis urease isoforms. This peptide induces several toxic effects on insects of different orders, including interference on muscle contractility in cockroaches, modulation of UDP-N-acetylglucosamine pyrophosphorylase (UAP) and nitric oxide synthase (NOS) activities in the central nervous system of triatomines, as well as activation of the immune system in Rhodnius prolixus. When injected, the peptide is lethal for R. prolixus and Triatoma infestans. Here, we evaluated Jaburetox toxicity to Nauphoeta cinerea cockroaches, exploring the effects on the central nervous system through the activities of UAP, NOS, acid phosphatases (ACP), and acetylcholinesterase (AChE). The results indicated that N. cinerea is not susceptible to the lethal effect of the peptide. Moreover, both in vivo and in vitro treatments with Jaburetox inhibited NOS activity, without modifying the protein levels. No alterations on ACP activity were observed. In addition, the enzyme activity of UAP only had its activity affected at 18 hr after injection. The peptide increased the AChE activity, suggesting a mechanism involved in overcoming the toxic effects. In conclusion, our findings indicate that Jaburetox affects the nitrinergic signaling as well as the AChE and UAP activities and establishes N. cinerea as a Jaburetox-resistant model for future comparative studies.

Gut microbes in cardiovascular diseases and their potential therapeutic applications

Microbial ecosystem comprises a complex community in which bacteria interact with each other. The potential roles of the intestinal microbiome play in human health have gained considerable attention. The imbalance of gut microbial community has been looked to multiple chronic diseases. Cardiovascular diseases (CVDs) are leading causes of morbidity worldwide and are influenced by genetic and environmental factors. Recent advances have provided scientific evidence that CVD may also be attributed to gut microbiome. In this review, we highlight the complex interplay between microbes, their metabolites, and the potential influence on the generation and development of CVDs. The therapeutic potential of using intestinal microbiomes to treat CVD is also discussed. It is quite possible that gut microbes may be used for clinical treatments of CVD in the near future.

[Prescription compatibility connotation and action mechanism of Siwu Decoction in treating primary dysmenorrhea]

The aim of this paper was to study the prescription compatibility connotation in the treatment of primary dysmenorrhea(PD) and verify the mechanism as predicted by network pharmacology of Siwu Decoction(SWD). Mice PD model was constructed by using estradiol benzoate-oxytocin. PD mice were randomly divided into 8 groups, namely normal group, model group, positive group, complete formula group, Rehmanniae Radix Praeparata-free group, Paeoniae Radix Alba-free group, volatile oil-free group, Chuan-xiong Rhizoma and Angelicae Sinensis Radix-free group. Latent time, writhing times, inhibition rate, prostaglandin F_2_α(PGF_2_α) and prostaglandin E_2(PGE_2) levels in serum, endothelin-1, Ca~(2+), expression levels of prostaglandin synthase 2 G/H(PTGS2), estrogen receptor(ESR1), glucocorticoid receptor gene(NR3 C1) mRNA and protein expression levels in the uterus homogenate and pathological changes of uterine tissue were index to explore the prescription compatibility connotation and verify the mechanism of SWD in the treatment of PD. Compared with the extraction liquid of the whole recipe, the effect of Rehmanniae Radix Praeparata-free group and Paeoniae Radix Alba-free group with volatile oil were slightly lower, the effect of essential oil-free group was significantly lower, and the effect of Chuanxiong Rhizoma and Angelicae Sinensis Radix-free group was worse than that of the whole recipe. The relative expression levels of PTGS2 protein and mRNA were significantly reduced by the SWD. The relative expressions of protein and mRNA of ESR1, NR3 C1 were significantly increased. SWD treats PD by regulating the expression of key proteins PTGS2, ESR1 and NR3 C1.Its main medicinal herbs were Angelicae Sinensis Radix and Chuanxiong Rhizoma. Active components were mainly in volatile oil, but Paeo-niae Radix Alba and Rehmanniae Radix Praeparata also had some contributions.

Antifungal Application of Rosin Derivatives from Renewable Pine Resin in Crop Protection

In the current work, we synthesized two series of dehydroabietyl amide derivatives from natural product rosin and evaluated their antifungal effects on Valsa mali, Phytophthora capsici, Botrytis cinerea, Sclerotinia sclerotiorum, and Fusarium oxysporum. In vitro and in vivo antifungal activities results indicated that rosin-based amide compounds containing thiophene heterocycles had better inhibitory effects on B. cinerea. In particular, compound 5b (5-fluoro-2-thiophene dehydroabietyl amide) exhibited the excellent antifungal properties against B. cinerea with an EC₅₀ of 0.490 mg/L, which was lower compared to the positive control penthiopyrad (0.562 mg/L). Physiological and biochemical studies showed that the primary action mechanism of compound 5b on B. cinerea changes mycelial morphology, increases cell membrane permeability, and inhibits the TCA pathway in respiratory metabolism. Furthermore, QSAR and SAR studies revealed that charge distribution of rosin-based amides derivatives have a key role in the antifungal activity through the hydrogen bonding, conjugation, and electrostatic interaction between the compounds and the receptors of the target. To sum up, this study contributes to the development of rosin-based antifungal agents with a novel structure and preferable biological activity.

The Regulatory Functions of Circular RNAs in Digestive System Cancers

Circular ribonucleic acids (circRNAs), which are a type of covalently closed circular RNA, are receiving increasing attention. An increasing amount of evidence suggests that circRNAs are involved in the biogenesis and development of multiple diseases such as digestive system cancers. Dysregulated circRNAs have been found to act as oncogenes or tumour suppressors in digestive system cancers. Moreover, circRNAs are related to ageing and a wide variety of processes in tumour cells, such as cell apoptosis, invasion, migration, and proliferation. Moreover, circRNAs can perform a remarkable multitude of biological functions, such as regulating splicing or transcription, binding RNA-binding proteins to enable function, acting as microRNA (miRNA) sponges, and undergoing translated into proteins. However, in digestive system cancers, circRNAs function mainly as miRNA sponges. Herein, we summarise the latest research progress on biological functions of circRNAs in digestive system cancers. This review serves as a synopsis of potential therapeutic targets and biological markers for digestive system cancer.

Improved synthetic route of exo-16,17-dihydro-gibberellin A5-13-acetate and the bioactivity of its derivatives towards Arabidopsis thaliana

BACKGROUND

The use of exo-16,17-dihydro-gibberellin A5-13-acetate (DHGA₅ ) in agriculture has been limited by its low synthetic yield. This study was aimed at optimizing the synthetic route of DHGA₅ , designing and synthesizing new derivatives with strong plant growth inhibitory activities.

RESULTS

Previous synthetic methods were replaced with a shorter, milder and faster reaction route with higher yield (76.3%) of DHGA₅ . Based on this novel route, a series of new derivatives were designed and synthesized using DHGA₅ as a lead compound and characterized and evaluated for biological activities in Arabidopsis thaliana. Among the 15 tested derivatives, compound 14j showed a lower medium inhibition concentration (IC₅₀ , 73 μm) in Arabidopsis than that of DHGA₅ (91 μm). Gibberellin deficient mutant assay further revealed that 14j had very different activities compared to DHGA₅ as it specifically inhibits gibberellin biosynthetic pathways. In addition, 14j does not influence the interaction between gibberellin receptors (GID1) and the master growth repressor (RGA) based on yeast two-hybrid assay.

CONCLUSION

The optimized synthetic route provides a promising method for large-scale preparation of DHGA₅ . Our biological assays indicate that 14j likely acts on gibberellin signaling elements other than GID1. These results indicate that novel plant growth regulators can be developed. © 2019 Society of Chemical Industry.

Baseline Sensitivity and Action Mechanism of Propamidine Against Alternaria brassicicola, the Causal Agent of Dark Leaf Spot on Cabbage

In the current study, a total of 53 isolates of Alternaria brassicicola collected from Shaanxi Province of China were characterized for their sensitivity to propamidine. The EC₅₀ (50% effective concentration) values for propamidine inhibiting mycelial growth and spore germination ranged from 0.515 to 3.247 µg/ml and 0.393 to 2.982 µg/ml, with average EC₅₀ values of 1.327 ± 0.198 µg/ml and 1.106 ± 0.113 µg/ml, respectively. In greenhouse experiments, propamidine at 100 µg/ml provided >90% efficacy against dark leaf spot on cabbage, which was higher than the efficacy obtained by azoxystrobin at the same concentration. After treatment with propamidine, fungal growth distortions were observed in the form of excess mycelial branching, thickened cell walls, decreased cell membrane permeability, and increased chitin content. Interestingly, colony color faded after treatment with propamidine compared with that of the untreated parental isolates. Importantly, the expressions of melanin biosynthesis-associated genes Amr1, Scd1, Brn1, and Brn2 were downregulated at different levels. The obtained baseline sensitivity and control efficacy data suggested that propamidine inhibited not only growth of A. brassicicola but also melanin biosynthesis, which could reduce the biocompatibility of A. brassicicola in the field. These biological characteristics encourage further investigation of the mechanism of action of propamidine against A. brassicicola.

[Short peptides: regulation of skin function during aging.]

Short peptides are applied for supporting skin function during ageing, because they can permeate the intact stratum corneum of the epidermis and affect the cells of the dermis. Short peptides are part of natural metabolism of cells and many of them have geroprotective properties. In the review we are considering the base sorts of peptides that are used for normalized skin fibroblasts function: matrikines, carnosine, collagen peptides, cytokine and growth factor analogs, defensins, immunoprotective peptides and polyfunctional peptides. Polyfunctional peptides (AcSDKP, KED, AEDG, AED) have geroprotective properties, slow apoptosis and stimulate skin cell proliferation, also increase functional activity of skin fibroblasts, normalize intracellular matrix hemostasis. Polyfunctional peptides are the antioxidants and immunoprotectors and can activate microcirculation in dermis. Peptide regulation of skin function during ageing are the fast-developing and prospective area in molecular gerontology.

[Network pharmacology research on high frequency use of Tibetan medicine in treatment of HAPC based on data mining]

Based on the results of previous data mining,the mechanism of high frequency use of Tibetan medicine in the treatment of high altitude polycythemia(HAPC) was analyzed in this study by network pharmacology. The author obtained the high frequency use data on Tibetan medicine Terminalia chebula,Aucklandia lappa,Crocus sativus and Myristica fragrans for the treatment of HAPC by data mining in the previous period. The first five main active ingredients of each high frequency Tibetan medicine were screened out by reviewing comprehensive literature and TCMSP database. The potential targets of each medicine were screened by PharmMapper and Drug Bank database,and then the targets were imported into MAS 3. 0 database to obtain the corresponding path information. The KEGG database was used for path annotation and GO function enrichment analysis. Finally,Cystoscope 3. 4. 0 software was used to construct " compound-target-path" network for four high-frequency Tibetan medicines. Among them,the target points of four herbs related to HAPC were 16(T. chebula),20(A. lappa),20(C. sativus),and 15(M. fragrans). The common target points included BHMT,F2,ADH5,AKR1 C2,GSK3 B,INSR and PDE4 B,involving pathways related to T. chebula(17),A. lappa(17),C. sativus(24) and M. fragrans(14),and the common pathway was metabolism of xenobiotics by cytochrome P450. The results showed that high-frequency Tibetan medicine had common pathways and targets in treating HAPC,such as T. chebula,A. lappa,C. sativus and M. fragrans.The medicines could reduce hemoglobin and enhance immunity by mediating cell proliferation and oxidative stress,exerting anti-inflammatory effects and participating in regulating blood vessels,showing therapeutic effects for HAPC. In this study,the multi-component,multi-target and multi-pathway mechanism of Tibetan medicine in preventing and treating HAPC was analyzed from the information level,providing a useful reference for further study of Tibetan medicine in preventing and treating plateau diseases from the multi-dimensional perspective.

Discovery of N-Aryl-pyridine-4-ones as Novel Potential Agrochemical Fungicides and Bactericides

A series of N-aryl-pyridine-4-one derivatives were designed and synthesized using maltol and antidesmone as lead compounds, and then their fungicidal/bactericidal activities and possible mechanism of action against Colletotrichum musae were explored. Most of these compounds exhibited significant fungicidal activity in vitro. Especially, compound 23 has more than 90% inhibitory activity against nine plant pathogenic fungi at 50 μg mL^-1, which is superior to azoxystrobin. Moreover, an in vivo bioassay also demonstrated that compound 23 exhibited high-efficiency broad-spectrum antifungal activity and can effectively control postharvest diseases of mango. In addition, it was found that compounds 22 and 23 can also effectively control rice bacterial leaf blight in pot experiments, which was even more effective than zhongshengmycin. Preliminary mechanism studies revealed that compound 23 may cause cell membrane and mitochondria destruction. These findings indicate that compound 23 can be used to develop potential agrochemical fungicides and bactericides.

Polygonum multiflorum-Induced Liver Injury: Clinical Characteristics, Risk Factors, Material Basis, Action Mechanism and Current Challenges

Polygonum multiflorum Thunb. (PM), called Heshouwu in China, is a popular Chinese medicine in clinical practice. Several clinical studies have been conducted to evaluate the traditional therapeutic claims and to study the potential therapeutic activity of PM in dyslipidemia and neurodegenerative diseases, highlighting available clinical evidence. In recent years, reports on clinical adverse reactions of Raw Radix P. multiflorum (RPM) and P. multiflorum Praeparata (PMP) have been on the increase, especially with respect to liver injury. Most liver injury cases had been assessed for causality using RUCAM (Roussel Uclaf Causality Assessment Method) in this paper. However, the components of PM responsible for the reported hepatotoxic effects have not yet been identified. Moreover, many of the reports are contradictory, while studies on the mechanism involved in PM-induced liver damage are not comprehensive. This study was aimed at reviewing the status of research on liver injury due to PM, including clinical characteristics, risk factors, material basis research and mechanism of action, with a view to understanding PM-induced hepatotoxicity, and taking reasonable and effective measures to prevent it. In short, quality control is still one of the major safety problems in TCM drug safety concerns. The model of safety monitoring and risk management of PM drugs is not yet developed. Indeed, the characteristics and risk factors associated with PM require both proper understanding and control of the risk by strengthening standardization of clinical applications, basic science research, quality control in manufacturing, active monitoring methodology and enhancement of international communication and cooperation. Measures should also be encouraged and implemented to promote healthy development of the TCM industry.

Synthesis of Thiazolium-Labeled 1,3,4-Oxadiazole Thioethers as Prospective Antimicrobials: In Vitro and in Vivo Bioactivity and Mechanism of Action

In this study, a type of thiazolium-labeled 1,3,4-oxadiazole thioether bridged by diverse alkyl chain lengths was constructed. The antimicrobial activity of the fabricated thioether toward plant pathogenic bacteria and fungi was then screened. Antibacterial evaluation indicated that title compounds possess specific characteristics that enable them to severely attack three phytopathogens, namely, Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Xanthomonas axonopodis pv. citri with minimal EC₅₀ values of 0.10, 3.27, and 3.50 μg/mL, respectively. Three-dimensional quantitative structure-activity relationship models were established to direct the following excogitation for exploring higher active drugs. The in vivo study against plant bacterial diseases further identified the prospective application of title compounds as alternative antibacterial agents. The proteomic technique, scanning electron microscopy patterns, and fluorescence spectrometry were exploited to investigate the antibacterial mechanism. Additionally, some target compounds performed superior inhibitory actions against three tested fungal strains. In view of their simple molecular architecture and highly efficient bioactivity, these substrates could be further explored as promising surrogates for fighting against plant microbial infections.

Dehydrozingerone Inspired Discovery of Potential Broad-Spectrum Fungicidal Agents as Ergosterol Biosynthesis Inhibitors

A series of dehydrozingerone derivatives were synthesized, and their fungicidal activities and action mechanism against Colletotrichum musae were evaluated. The bioassay result showed that most compounds exhibited excellent fungicidal activity in vitro at 50 μg mL^-1. Compounds 13, 16, 18, 19, and 27 exhibited broad-spectrum fungicidal activity; especially, compounds 19 and 27 were found to have more potent fungicidal activity than azoxystrobin. The EC₅₀ values of compounds 19 and 27 against Rhizoctonia solani were 0.943 and 0.161 μg mL^-1 respectively. Moreover, compound 27 exhibited significant in vitro bactericidal activity against Xanthomonas oryzae pv. oryzae, with an EC₅₀ value of 11.386 μg mL^-1, and its curative effect (49.64%) and protection effect (51.74%) on rice bacterial blight disease was equivalent to that of zhongshengmycin (42.90%, 40.80% respectively). Compound 27 could also effectively control gray mold (87.10%, 200 μg mL^-1) and rice sheath blight (100%, 200 μg mL^-1; 82.89%, 100 μg mL^-1) in vivo. Preliminary action mechanism study showed that compound 27 mainly acted on the cell membrane and significantly inhibited ergosterol biosynthesis in Colletotrichum musae.

Identification of Racemic and Chiral Carbazole Derivatives Containing an Isopropanolamine Linker as Prospective Surrogates against Plant Pathogenic Bacteria: In Vitro and In Vivo Assays and Quantitative Proteomics

Recent observations on the emergence of drug-resistant plant pathogenic bacteria have highlighted and elicited an acute campaign to develop novel, highly efficient antibiotic surrogates for managing bacterial diseases in agriculture. Thus, a type of racemic and chiral carbazole derivative containing an isopropanolamine pattern was systematically synthesized to discover low-cost and efficient antibacterial candidates. Screening results showed that compounds 2f, 6c, and 2j could significantly suppress the growth of tested plant pathogens, namely Xanthomonas oryzae pv oryzae, X. axonopodis pv citri, and Pseudomonas syringae pv actinidiae, and provided the corresponding EC₅₀ values of 1.27, 0.993, and 0.603 μg/mL, which were significantly better than those of existing commercial drugs. In vivo studies confirmed their prospective applications for controlling plant bacterial diseases. Label-free quantitative proteomics analysis indicated that compound 2f could dramatically induce the up- and down-regulation of a total of 247 differentially expressed proteins, which was further validated by the parallel reaction monitoring technique. Moreover, fluorescence spectra and SEM images were obtained to further explore the antibacterial mechanism.

Micronized and Heat-Treated Lactobacillus plantarum LM1004 Stimulates Host Immune Responses Via the TLR-2/MAPK/NF-κB Signalling Pathway In Vitro and In Vivo

Although nanometric dead Lactobacillus plantarum has emerged as a potentially important modulator of immune responses, its underlying mechanism of action has not been fully understood. This study aimed to identify the detailed biochemical mechanism of immune modulation by micronized and heat-treated L. plantarum LM1004 (MHT-LM1004, <1 μm in size). MHT-LM1004 was prepared from L. plantarum LM1004 via culture in a specifically designed membrane bioreactor and heat treatment. MHT-LM1004 was shown to effectively induce the secretion of TNF-α and IL-6 and the mRNA expression of inducible nitric oxide synthase (iNOS). MHT-LM1004 enhanced the expression of TLR-2, phosphorylation of MAPKs (ERK), and nuclear translocation of NF-κB in a dose-dependent manner. Oral administration of MHT-LM1004 (4 × 10⁹ or 4 × 10¹¹ cells/kg mouse body weight) increased the splenocyte proliferation and serum cytokine levels. These results suggested that MHT-LM1004 effectively enhances early innate immunity by activating macrophages via the TLR-2/MAPK/NF-κB signalling pathway and that this pathway is one of the major routes in immune modulation by the Lactobacillus species.

Plant-Derived Alkaloids: The Promising Disease-Modifying Agents for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) represents a group of intestinal disorders with self-destructive and chronic inflammation in the digestive tract, requiring long-term medications. However, as many side effects and drug resistance are frequently encountered, safer and more effective agents for IBD treatment are urgently needed. Over the past few decades, a variety of natural alkaloids made of plants or medicinal herbs have attracted considerable interest because of the excellent antioxidant and anti-inflammatory properties; additionally, these alkaloids have been reported to reduce the colonic inflammation and damage in a range of colitic models. In this review paper, we summarize the recent findings regarding the anti-colitis activity of plant-derived alkaloids and emphasize their therapeutic potential for the treatment of IBD; obvious improvement of the colonic oxidative and pro-inflammatory status, significant preservation of the epithelial barrier function and positive modulation of the gut microbiota are the underlying mechanisms for the plant-derived alkaloids to treat IBD. Further clinical trials and preclinical studies to unravel the molecular mechanism are essential to promote the clinical translation of plant-derived alkaloids for IBD.

Rational Optimization and Action Mechanism of Novel Imidazole (or Imidazolium)-Labeled 1,3,4-Oxadiazole Thioethers as Promising Antibacterial Agents against Plant Bacterial Diseases

The emergence and widespread occurrence of plant bacterial diseases that cause global production constraints have become major challenges to agriculture worldwide. To promote the discovery and development of new bactericides, imidazole-labeled 1,3,4-oxadiazole thioethers were first fabricated by integrating the crucially bioactive scaffolds of the imidazole motif and 1,3,4-oxadiazole skeleton in a single molecular architecture. Subsequently, a superior antibacterial compound A₆ was gradually discovered possessing excellent competence against plant pathogens Xanthomonas oryzae pv oryzae and Xanthomonas axonopodis pv citri with EC₅₀ values of 0.734 and 1.79 μg/mL, respectively. These values were better than those of commercial agents bismerthiazol (92.6 μg/mL) and thiodiazole copper (77.0 μg/mL). Further modifying the imidazole moiety into the imidazolium scaffold led to the discovery of an array of potent antibacterial compounds providing the corresponding minimum EC₅₀ values of 0.295 and 0.607 μg/mL against the two strains. Moreover, a plausible action mechanism for attacking pathogens was proposed based on the concentration dependence of scanning electron microscopy, transmission electron microscopy, and fluorescence microscopy images. Given the simple molecular structures, easy synthetic procedure, and highly efficient bioactivity, imidazole (or imidazolium)-labeled 1,3,4-oxadiazole thioethers can be further explored and developed as promising indicators for the development of commercial drugs.

Potential of Plant-sourced Phenols for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an uncontrolled chronic inflammatory intestinal disorder, which requires medications for long-term therapy. Facing the challenges of severe side effects and drug resistance of conventional medications, to develop the strategies meet the stringent safety and effectiveness in the long-term treatment are urgent in the clinics. In this regard, a growing body of evidence confirms plant-sourced phenols, such as flavonoids, catechins, stilbenes, coumarins, quinones, lignans, phenylethanoids, cannabinoid phenols, tannins, phenolic acids and hydroxyphenols, exert potent protective benefits with fewer undesirable effects in conditions of acute or chronic intestinal inflammation through improvement of colonic oxidative and pro-inflammatory status, preservation of the epithelial barrier function and modulation of gut microbiota. In this review, the great potential of plant-sourced phenols and their action mechanisms for the treatment or prevention of IBD in recent research are summarized, which may help further development of new preventive/adjuvant regimens for IBD.

Molecular basis and mechanism underlying the insecticidal activity of venoms and toxins from Latrodectus spiders

Latrodectus species are among the most venomous of spiders, with abundant toxic proteinaceous components in their venomous glands and other tissues, as well as their eggs. To date, several proteinaceous toxins with insecticidal potential, including α-insectotoxin and δ-insectotoxin, two of the most potent known insecticidal toxins, have been purified and characterized by comprehensively utilizing conventional biochemical techniques. This has greatly enhanced our knowledge of the molecular basis and mechanism of action of their toxicity. Application of proteomic and transcriptomic techniques further revealed the synergistic action of multiple Latrodectus proteinaceous toxins and toxin-like components. Insecticidal toxins from Latrodectus spiders have great potential in insect pest control; however, more studies are needed to further reveal their mechanisms of action and understand their structures and properties before any practical application, for example, the insecticidal toxin-containing fusion proteins with oral activity. Here, we review current knowledge of the molecular basis and mechanism of action underlying the insecticidal activity of venoms and toxins from Latrodectus spiders, and examine their potential application in insect pest control. © 2018 Society of Chemical Industry.

Biosynthesis of Metal Nanoparticles via Microbial Enzymes: A Mechanistic Approach

During the last decade, metal nanoparticles (MtNPs) have gained immense popularity due to their characteristic physicochemical properties, as well as containing antimicrobial, anti-cancer, catalyzing, optical, electronic and magnetic properties. Primarily, these MtNPs have been synthesized through different physical and chemical methods. However, these conventional methods have various drawbacks, such as high energy consumption, high cost and the involvement of toxic chemical substances. Microbial flora has provided an alternative platform for the biological synthesis of MtNPs in an eco-friendly and cost effective way. In this article we have focused on various microorganisms used for the synthesis of different MtNPs. We also have elaborated on the intracellular and extracellular mechanisms of MtNP synthesis in microorganisms, and have highlighted their advantages along with their challenges. Moreover, due to several advantages over chemically synthesized nanoparticles, the microbial MtNPs, with their exclusive and dynamic characteristics, can be used in different sectors like the agriculture, medicine, cosmetics and biotechnology industries in the near future.

Antifungal Activity and Action Mechanism of Ginger Oleoresin Against Pestalotiopsis microspora Isolated From Chinese Olive Fruits

Pestalotiopsis microspora (P. microspora) is one of dominant pathogenic fungi causing rotten disease in harvested Chinese olive (Canarium album Lour.) fruits. The purposes of this study were to evaluate the antifungal activities of ginger oleoresin (GO) against P. microspora and to illuminate the underlying action mechanisms. The in vitro assays indicate that GO exhibited strong antifungal activity against mycelial growth of P. microspore, and with 50%-inhibition concentration (EC₅₀) and 90%-inhibition concentration (EC₉₀) at 2.04 μL GO and 8.87 μL GO per mL propylene glycol, respectively, while the minimal inhibitory concentration (MIC) and minimal fungicidal concentration were at 10 μL GO and 30 μL GO per mL propylene glycol, respectively. Spore germination of P. microspora was inhibited by GO in a dose-dependent manner, and with 100% inhibition rate at the concentration of 8 μL GO per mL propylene glycol. Compared to the control, the cellular membrane permeability of P. microspora increased due to severe leakage of intercellular electrolytes, soluble proteins, and total sugars with the treatments (EC₅₀, EC₉₀) by GO during incubation. In addition, analysis of fatty acid contents and compositions in cellular membrane by GC-MS indicated that GO could significantly promote the degradation or peroxidation of unsaturated fatty acids in P. microspore, resulting in the enhancement of membrane fluidity. Moreover, observations of microstructure further showed the damage to plasma membrane and morphology of P. microspora caused by GO, which resulted in distortion, sunken and shriveled spores and mycelia of the pathogen. Furthermore, in vivo assay confirmed that over 3 MIC GO treatments remarkably suppressed disease development in P. microspore inoculated-Chinese olive fruit. These results demonstrate that owing to its strong antifungal activity, GO can be used as a promising antifungal agent to inhibit the growth of pathogenic fungi in Chinese olives.

A network pharmacology approach to determine the synergetic mechanisms of herb couple for treating rheumatic arthritis

Purpose

The purpose of this study was to investigate the therapeutic mechanism(s) of Clematis chinensis Osbeck/Notopterygium incisum K.C. Ting ex H.T (CN).

Methods

A network pharmacology approach integrating prediction of ingredients, target exploration, network construction, module partition and pathway analysis was used.

Results

This approach successfully helped to identify 12 active ingredients of CN, interacting with 13 key targets (Akt1, STAT3, TNFsf13, TP53, EPHB2, IL-10, IL-6, TNF, MAPK8, IL-8, RELA, ROS1 and STAT4). Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that CN-regulated pathways were mainly classified into signal transduction and immune system.

Conclusion

The present work may help to illustrate the mechanism(s) of action of CN, and it may provide a better understanding of antirheumatic effects.

The antibacterial activity and modes of LI-F type antimicrobial peptides against Bacillus cereus in vitro

AIMS

LI-Fs are a family of highly potent cyclic lipodepsipeptide antibiotics with a broad antimicrobial spectrum (Gram-positive bacteria and fungi). In this study, LI-F-type antimicrobial peptides (AMP-jsa9) composing of LI-F03a, LI-F03b, LI-F04a, LI-F04b and LI-F05b were isolated from Paenibacillus polymyxa JSA-9. To better understand the antimicrobial mechanism of AMP-jsa9, the potency and action(s) of AMP-jsa9 against Bacillus cereus were examined.

METHODS AND RESULTS

Flow cytometry, confocal laser microscopy, scanning electron microscopy, transmission electron microscopy (TEM) and atomic force microscopy observation, as well as determination of peptidoglycan and cell wall-associated protein and other methods were used. The results indicate that AMP-jsa9 exhibits strong, broad-spectrum antimicrobial activity. Moreover, AMP-jsa9 targets the cell wall and membrane of B. cereus to impair membrane integrity, increase membrane permeability and enhance cytoplasm leakage (e.g. K⁺ , protein, nucleic acid). This leads to bacterial cells with irregular, withered and coarse surfaces. In addition, AMP-jsa9 is also able to bind to DNA and break down B. cereus biofilms.

CONCLUSIONS

In this study, the action mechanism of LI-Fs against B. cereus was clarified in details.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study provide a theoretical basis for utilizing AMP-jsa9 or similar analogues as natural and effective preservatives in the food and feed industries. These efforts could also stimulate research activities interested in understanding the specific effects of other antimicrobial agents.

Effects of collagen peptides intake on skin ageing and platelet release in chronologically aged mice revealed by cytokine array analysis

Action mechanisms underlying various biological activities of collagen peptides (CPs) remained to be elucidated. Cytokines may play an important role in mediating these health benefits of CPs. This study aimed to systemically examine the cytokines in skin and blood regulated by CPs intake. Thirteen‐month‐old female Kunming mice were administered with CPs for 2 months (0 or 400 mg/kg bodyweight/day). The cytokines in skin and plasma were analysed using a 53‐cytokine array and corresponding ELISA kits. In skin, CPs intake significantly down‐regulated placenta growth factor (PIGF‐2), insulin‐like growth factor (IGF)‐binding protein (IGFBP) ‐2 and IGFBP‐3, and up‐regulated platelet factor 4 (PF4), serpin E1 and transforming growth factor (TGF)‐β₁. CPs treatment also increased the type I collagen mRNA and protein levels and improved the aged skin collagen fibres. In plasma, nine cytokines were significantly down‐regulated by CPs intake compared to the model group: fibroblast growth factor (FGF)‐2, heparin‐binding (HB) epidermal growth factor (EGF)‐like growth factor (HB‐EGF), hepatocyte growth factor (HGF), platelet‐derived growth factor (PDGF)‐AB/BB, vascular endothelial growth factor (VEGF), chemokine (C‐X‐C motif) ligand 1 (KC), matrix metalloproteinase (MMP)‐9, interleukin (IL)‐1α and IL‐10; 2 cytokines were significantly up‐regulated, including TGF‐β₁ and serpin F1. Furthermore, CPs intake significantly decreased the level of platelet release indicators in the plasma and washed platelets, including PF4, granule membrane protein (GMP)‐140, β‐thromboglobulin and serotonin. These results provide a mechanism underlying anti‐skin ageing by CPs intake and highlight potential application of CPs as a healthcare supplement to combat cancer and cardiovascular disease by inhibiting platelet release.

Exploring New Mechanisms for Effective Antimicrobial Materials: Electric Contact-Killing Based on Multiple Schottky Barriers

The increasing threat of multidrug-resistance organisms is a cause for worldwide concern. Progressively microorganisms become resistant to commonly used antibiotics, which are a healthcare challenge. Thus, the discovery of new antimicrobial agents or new mechanisms different from those used is necessary. Here, we report an effective and selective antimicrobial activity of microstructured ZnO (Ms-ZnO) agent through the design of a novel star-shaped morphology, resulting in modulation of surface charge orientation. Specifically, we find that Ms-ZnO particles are composed of platelet stacked structure, which generates multiple Schottky barriers due to the misalignment of crystallographic orientations. We also demonstrated that this effect allows negative charge accumulation in localized regions of the structure to act as "charged domain walls", thereby improving the antimicrobial effectiveness by electric discharging effect. We use a combination of field emission scanning electron microscopy (FE-SEM), SEM-cathodoluminescence imaging, and Kelvin probe force microscopy (KPFM) to determine that the antimicrobial activity is a result of microbial membrane physical damage caused by direct contact with the Ms-ZnO agent. It is important to point out that Ms-ZnO does not use the photocatalysis or the Zn²⁺ released as the main antimicrobial mechanism, so consequently this material would show low toxicity and robust stability. This approach opens new possibilities to understand both the physical interactions role as main antimicrobial mechanisms and insight into the coupled role of hierarchical morphologies and surface functionality on the antimicrobial activity.