Three novel umami peptides derived from the alcohol extract of the Pacific oyster(Crassostrea gigas):identification,characterizations and interactions with T1R1/T1R3 taste receptors

Oyster(Crassostrea gigas),the main ingredient of oyster sauce,has a strong umami taste.In this study,three potential umami peptides,FLNQDEEAR(FR-9),FNKEE(FE-5),and EEFLK(EK-5),were identified and screened from the alcoholic extracts of the oyster using nano-HPLC-MS/MS analysis,i Umami-Scoring Card Method(i Umami-SCM)database and molecular docking(MD).Sensory evaluation and electronic tongue analysis were further used to confirm their tastes.The threshold of the three peptides ranged from 0.38 to 0.55 mg/m L.MD with umami receptors T1R1/T1R3 indicated that the electrostatic interaction and hydrogen bond interaction were the main forces involved.Besides,the Phe592 and Gln853 of T1R3 were the primary docking site for MD and played an important role in umami intensity.Peptides with two Glu residues at the terminus had stronger umami,especially at the C-terminus.These results contribute to the understanding of umami peptides in oysters and the interaction mechanism between umami peptides and umami receptors.

Emerging structures and dynamic mechanisms ofγ-secretase for Alzheimer’s disease

γ-Secretase,called“the proteasome of the membrane,”is a membrane-embedded protease complex that cleaves 150+peptide substrates with central roles in biology and medicine,including amyloid precursor protein and the Notch family of cell-surface receptors.Mutations inγ-secretase and amyloid precursor protein lead to early-onset familial Alzheimer’s disease.γ-Secretase has thus served as a critical drug target for treating familial Alzheimer’s disease and the more common late-onset Alzheimer’s disease as well.However,critical gaps remain in understanding the mechanisms of processive proteolysis of substrates,the effects of familial Alzheimer’s disease mutations,and allosteric modulation of substrate cleavage byγ-secretase.In this review,we focus on recent studies of structural dynamic mechanisms ofγ-secretase.Different mechanisms,including the“Fit-Stay-Trim,”“Sliding-Unwinding,”and“Tilting-Unwinding,”have been proposed for substrate proteolysis of amyloid precursor protein byγ-secretase based on all-atom molecular dynamics simulations.While an incorrect registry of the Notch1 substrate was identified in the cryo-electron microscopy structure of Notch1-boundγ-secretase,molecular dynamics simulations on a resolved model of Notch1-boundγ-secretase that was reconstructed using the amyloid precursor protein-boundγ-secretase as a template successfully capturedγ-secretase activation for proper cleavages of both wildtype and mutant Notch,being consistent with biochemical experimental findings.The approach could be potentially applied to decipher the processing mechanisms of various substrates byγ-secretase.In addition,controversy over the effects of familial Alzheimer’s disease mutations,particularly the issue of whether they stabilize or destabilizeγ-secretase-substrate complexes,is discussed.Finally,an outlook is provided for future studies ofγ-secretase,including pathways of substrate binding and product release,effects of modulators on familial Alzheimer’s disease mutations of theγ-secretase-substrate complexes.Comprehensive understanding of the functional mechanisms ofγ-secretase will greatly facilitate the rational design of effective drug molecules for treating familial Alzheimer’s disease and perhaps Alzheimer’s disease in general.

Comprehensive Assessment of Anxiolytic Properties in 4-HPAA Derivatives: Bridging in Vivo Validation and Molecular Docking Analyses

Anxiety is a significant mental health issue that substantially affects an individual’s quality of life. Feelings of uneasiness, irritability, and sleep disturbances characterize it. 4-Hydroxyphenyl acetic acid (4-HPAA) is identified in brain cells as a physiological byproduct of tyramine. This study hypothesizes that 4-HPAA may regulate anxiety due to its anxiolytic properties, acting as a modulator of the GABAergic system, which plays a crucial role in the pathophysiology of anxiety disorders. Our study aims to enhance the anxiolytic effects of 4-HPAA through chemical modification to improve its pharmacokinetic properties. Three derivatives, namely Isopropyl-4-hydroxy-[phenyl] acetate (IHPA), Isopropyl-4-hydroxy-[phenyl] acetate (MPAA), and 4-methoxyphenyl acetate (MPHA), have been synthesized from 4-HPAA. This assessment will use well-established animal models, specifically the Elevated Plus-Maze (EPM) and Zero Maze (EZM) tests, selected for their validity in replicating anxiety-like symptoms in animals. Chronic caffeine administration via drinking water (0.3 g/l for 14 days) was employed to induce an anxiety state for testing purposes. IHPA and MPAA demonstrated significant anxiolyticactivity when tested in the EPM and EZM experiments. Molecular docking simulations using AutoDock Vina indicated that 4-HPAA derivatives had docking scores ranging from −5.8 to −4.8 kcal/mol, compared to the standard anxiolytic medication Diazepam, which scored −7.1 kcal/mol. These scores suggest a potential for 4-HPAA derivatives to interact effectively with the Gamma-aminobutyric acid (GABA_A) receptor. In conclusion, our in vivo and in silico analyses indicate a promising anxiolytic potential for 4-HPAA derivatives.

Medicinal chemistry strategies towards the development of non-covalent SARS-CoV-2 Mpro inhibitors

The main protease(M^(pro))of SARS-CoV-2 is an attractive target in anti-COVID-19 therapy for its high conservation and major role in the virus life cycle.The covalent M^(pro)inhibitor nirmatrelvir(in combination with ritonavir,a pharmacokinetic enhancer)and the non-covalent inhibitor ensitrelvir have shown efficacy in clinical trials and have been approved for therapeutic use.Effective antiviral drugs are needed to fight the pandemic,while non-covalent M^(pro)inhibitors could be promising alternatives due to their high selectivity and favorable druggability.Numerous non-covalent M^(pro)inhibitors with desirable properties have been developed based on available crystal structures of M^(pro).In this article,we describe medicinal chemistry strategies applied for the discovery and optimization of non-covalent M^(pro)inhibitors,followed by a general overview and critical analysis of the available information.Prospective viewpoints and insights into current strategies for the development of non-covalent M^(pro)inhibitors are also discussed.

Xanthine oxidase inhibitors from Archidendron clypearia(Jack.) I.C. Nielsen: Results from systematic screening of Vietnamese medicinal plants

Objective: To screen Vietnamese medicinal plants for xanthine oxidase(XO) inhibitory activity and to isolate XO inhibitor(s) from the most active plant. Methods: The plants materials were extracted by methanol. The active plant materials were fractionated using different organic solvents, including n-hexane, ethyl acetate, and n-butanol. Bioassay-guided fractionation and column chromatography were used to isolate compounds. The compounds structures were elucidated by analysis of spectroscopic data, including IR, MS, and NMR. Results: Three hundreds and eleven methanol extracts(CME) belonging to 301 Vietnamese herbs were screened for XO inhibitory activity. Among these plants, 57 extracts displayed XO inhibitory activity at 100 μg/m L with inhibition rates of over 50%. The extracts of Archidendron clypearia, Smilax poilanei, Linociera ramiflora and Passiflora foetida exhibited the greatest potency with IC_(50) values below 30 μg/m L. Chemical study performed on the extract of Archidendron clypearia resulted in the isolation of six compounds, including 1-octacosanol, docosenoic acid, daucosterol, methyl gallate, quercitrin and(-)-7-O-galloyltricetiflavan. The compound(-)-7-O-galloyltricetiflavan showed the most potent XO inhibitory activity with an IC_(50) value of 25.5 μmol/L. Conclusions: From this investigation, four Vietnamese medicinal plants were identified to have XO inhibitory effects with IC_(50) values of the methanol extracts below 30 μg/m L. Compound(-)-7-O-galloyltricetiflavan was identified as an XO inhibitor from Archidendron clypearia with IC_(50) value of 25.5 μmol/L.

Immunomodulatory effect of ethanol-soluble polypeptides from Atlantic cod (Gadus morhua)

There are many active substances in Atlantic cod(Gadus morhua)explaining the variety of biological activities.In order to study the immunomodulatory activity and the mechanism of Atlantic cod peptides at the cellular level.In this study,cod peptides were isolated by 80%ethanol extraction method,the isolated ethanol-soluble cod peptides(CP-ES)were investigated and their immunomodulatory activity was verified.Additionally,CP-ES showed lower molecular weight and more hydrophobic amino acids.CP-ES could promote the proliferation of spleen lymphocytes and T lymphocytes in mice,suggesting that CP-ES may regulate adaptive immunity.It promoted the release of NO and the expression of iNOS,TNF-α,IL-6 and IL-1βgenes in macrophages,suggesting that CP-ES may regulate innate immunity.CP-ES could promote the expression of TLR2 gene,and the peptides identified in CP-ES were docked with TLR2 to predict the peptides playing a major role in CP-ES.These results suggested that CP-ES may regulate the immune activity of both innate and adaptive lines.

Development status of novel spectral imaging techniques and application to traditional Chinese medicine

Traditional Chinese medicine(TCM)is a treasure of the Chinese nation,providing effective solutions to current medical requisites.Various spectral techniques are undergoing continuous development and provide new and reliable means for evaluating the efficacy and quality of TCM.Because spectral techniques are noninvasive,convenient,and sensitive,they have been widely applied to in vitro and in vivo TCM evaluation systems.In this paper,previous achievements and current progress in the research on spectral technologies(including fluorescence spectroscopy,photoacoustic imaging,infrared thermal imaging,laser-induced breakdown spectroscopy,hyperspectral imaging,and surface enhanced Raman spectroscopy)are discussed.The advantages and disadvantages of each technology are also presented.Moreover,the future applications of spectral imaging to identify the origins,components,and pesticide residues of TCM in vitro are elucidated.Subsequently,the evaluation of the efficacy of TCM in vivo is presented.Identifying future applications of spectral imaging is anticipated to promote medical research as well as scientific and technological explorations.

Targeting biosignatures of hyperglycemia and oxidative stress in diabetes comorbid depressive rats: effectiveness of hydroethanolic extract of the whole plant of Ludwigia octovalvis

Background:The prime objective of the current research was to evaluate the whole plant hydroalcoholic extract of Ludwigia octovalvis(HLO)against hyperglycemia,and oxidative stress biomarkers in rats induced with diabetes comorbid depression,diabetes comorbid depression(streptozotocin-nicotinamide+electric footshocks).Methods:2,2-Diphenyl-1-picrylhydrazyl assay of HLO versus ascorbic acid was done.Effects of 200 and 400 mg/kg body weight/day HLO doses versus 25 mg/kg body weight/day metformin was studied through insulin,glucose,superoxide dismutase,lipid peroxidation,catalase,and behavioral assessment(forced swim and open field tests).Results:IC50 values of HLO and ascorbic acid were 33.52 and 27.86μg/mL respectively.Both the HLO doses showed intended results with respect to oxidative stress biomarkers in diabetes comorbid depression rats in comparison to metformin.Open field test showed better results for HLO in diabetes comorbid depression rats.However,hypoglycemic effects,and forced swim test performance of metformin was slightly higher than the 400 mg dose,followed by the 200 mg dose of HLO.Ethyl gallate,gallic acid,β-sitosterol,and quercetin in HLO might resulted in attenuating diabetic as well as depression biomarkers.Conclusion:Inhibition of glucosidase and lipase activity,and AMP-activated protein kinase phosphorylation might be the possible biochemical changes occurred in HLO treated rats.

Assessment of the effects of intrastromal injection of adipose-derived stem cells in keratoconus patients

·AIM: To evaluate the efficacy and safety of intrastromal transplantation of adipose-derived stem cells(ASCs) in keratoconus patients.·METHODS: This study was conducted on 8 eyes of 8 patients with moderate to severe keratoconus. In the patients, ophthalmic assessments including visual acuity, refraction, slit lamp examination, fundoscopy, corneal topography, and confocal microscopy were performed. Autologous stem cells were used. The isolated stem cells were injected into the corneal stroma by using femtosecond laser. Surgical procedure was similar to intracorneal ring implantation. All patients were re-assessed 1, 3, and 6mo after surgery.·RESULTS: The baseline mean visual acuity was 0.48±0.18 and improved to 0.66±0.17 after surger y and final acuity increased by 1.85±0.80 lines(P=0.001).The mean spherical refraction of patients improved 0.34 ± 0.35 D(P=0.039), and the mean cylindrical refraction of patients improved 0.84±0.23 D(P=0.016). The mean flat keratometry decreased 0.78±0.71 D(P=0.017), and the mean steep keratometry decreased 0.59±0.68 D(P=0.023). The mean central corneal thickness of patients improved of 6.29±4.47 μm(P=0.03). The mean keratocyte density at the anterior and middle stroma of cornea increased(P<0.05) but remained stable at the posterior stroma after 6mo. All patients had no complications and their corneas remained transparent. ·CONCLUSION: Intrastromal transplantation of ASCs has positive effects on vision and refractive parameters in most patients with keratoconus. After six months, visual acuity improved moderately, corneal parameters reduced slightly, and stromal keratocytes density increased. This modality is safe, and patients do not have any complications.

Role of baricitinib in COVID-19 patients:A systematic review and meta-analysis

BACKGROUND Recent studies have indicated the use of baricitinib in coronavirus disease 2019(COVID-19)patients.However,the use of baricitinib in COVID-19 patients is unclear so far.AIM To determine the precise role of baricitinib in the mortality of COVID-19 patients.METHODS The relevant studies were searched in PubMed,Google scholar,and Clinical trials registries till July 13,2021 and sorted out based on inclusion and exclusion criteria.The quality of studies was assessed using Newcastle-Ottawa Scale.A random-effect model was used,and the pooled estimate was calculated as the odds ratio with a 95%confidence interval using Rev Man 5.RESULTS A total of 11 studies(4 observational and 7 clinical trials)were found relevant for analysis.The overall estimate measure in terms of odds ratio for observational studies was 0.42[0.11,1.67],whereas for clinical trials it was 0.37[0.09,1.46],indicating a non-significant reduction in COVID-19 patient deaths in the baricitinib group versus the non-baricitinib group.CONCLUSION More studies are required to confirm the role of baricitinib in the deaths of COVID-19 patients.

Pharmacodynamics of frigid zone plant Taxus cuspidata S.et Z.against skin melanin deposition,oxidation,inflammation and allergy

Background:Taxus cuspidata S.et Z.is a precious species of frigid zone plant belonging to the Taxaceae family,which possesses anticancer,anti-inflammatory,hypoglycemic,and antibacterial pharmacological properties.While taxane extracted from Taxus chinensis has been reported to elicit antioxidant activities,whether Taxus cuspidata S.et Z.has skin-protective actions against injuries remained unknown.This study aims to explore the pharmacological effects of three Taxus extracts on skin melanin deposition,oxidation,inflammation,and allergy so as to provide new ideas for the prevention and treatment of various diseases related to skin damage.Methods:Skin melanin deposition was evaluated by measuring melanin content in the skin of guinea pigs by alkali lysis method.Antioxidant capacity was evaluated by measuring superoxide dismutase(SOD)concentration and glutathione(GSH)content in skin tissue homogenates of Kunming mice by SOD assay kit and micro reduced GSH assay kit.The quantitative real-time polymerase chain reaction(qRT-PCR)and western blotting were used to examine the levels of both SOD and recombinant glutathione peroxidase 4(GPX4).Skin inflammation was evaluated by xylene-induced ear swelling test and egg-white-induced paw swelling test in mice.In a mouse model of skin allergy induced by 4-aminopyridine(4-AP),allergy was determined by licking body counts and histamine concentrations in tissue homogenates using enzyme-linked immunosorbent assay(ELISA)kits.Two proinflammatory factors tumor necrosis factor(TNF)-αand interleukin(IL)-1βwere measured by qRT-PCR.Hematoxylin and eosin(HE)staining was conducted to assess the degree of skin lesion.Results:All three Taxus extracts including Taxus chinensis essential oil,Taxus chinensis extract and Taxus chinensis extract compound reduced the melanin deposits in the back skin relative to the non-treated control animals,of which Taxus chinensis essential oil produced the greatest effect.In contrast,the three Taxus extracts elevated SOD and GSH levels in the skin tissues,and the highest increase was seen with Taxus chinensis essential oil.Three Taxus extracts,especially Taxus chinensis essential oil,effectively reduce the rate of ear and paw swelling.All three Taxus extracts reduced the number of body licks,the levels of TNF-αand IL-1β,and the histamine content in tissue homogenates of mice and alleviated skin damage.Consistently,Taxus chinensis essential oil yielded the greatest magnitude of decreases.Conclusion:While all three Taxus extracts possessed the anti-skin melanin deposition,oxidation,and allergy properties,Taxus chinensis essential oil produced the superior effects.

Transformation of peptides to small molecules in medicinal chemistry:Challenges and opportunities

Peptides are native binders involved in numerous physiological life procedures,such as cellular signaling,and serve as ready-made regulators of biochemical processes.Meanwhile,small molecules compose many drugs owing to their outstanding advantages of physiochemical properties and synthetic convenience.A novel field of research is converting peptides into small molecules,providing a convenient portable solution for drug design or peptidomic research.Endowing properties of peptides onto small molecules can evolutionarily combine the advantages of both moieties and improve the biological druggability of molecules.Herein,we present eight representative recent cases in this conversion and elaborate on the transformation process of each case.We discuss the innovative technological methods and research approaches involved,and analyze the applicability conditions of the approaches and methods in each case,guiding further modifications of peptides to small molecules.Finally,based on the aforementioned cases,we summarize a general procedure for peptide-to-small molecule modifications,listing the technological methods available for each transformation step and providing our insights on the applicable scenarios for these methods.This review aims to present the progress of peptide-to-small molecule modifications and propose our thoughts and perspectives for future research in this field.

Stiffness-tunable biomaterials provide a good extracellular matrix environment for axon growth and regeneration

Neuronal growth, extension, branching, and formation of neural networks are markedly influenced by the extracellular matrix—a complex network composed of proteins and carbohydrates secreted by cells. In addition to providing physical support for cells, the extracellular matrix also conveys critical mechanical stiffness cues. During the development of the nervous system, extracellular matrix stiffness plays a central role in guiding neuronal growth, particularly in the context of axonal extension, which is crucial for the formation of neural networks. In neural tissue engineering, manipulation of biomaterial stiffness is a promising strategy to provide a permissive environment for the repair and regeneration of injured nervous tissue. Recent research has fine-tuned synthetic biomaterials to fabricate scaffolds that closely replicate the stiffness profiles observed in the nervous system. In this review, we highlight the molecular mechanisms by which extracellular matrix stiffness regulates axonal growth and regeneration. We highlight the progress made in the development of stiffness-tunable biomaterials to emulate in vivo extracellular matrix environments, with an emphasis on their application in neural repair and regeneration, along with a discussion of the current limitations and future prospects. The exploration and optimization of the stiffness-tunable biomaterials has the potential to markedly advance the development of neural tissue engineering.

DNA G-Quadruplexes as Targets for Natural Product Drug Discovery

DNA guanine(G)-quadruplexes(G4s)are unique secondary structures formed by two or more stacked Gtetrads in G-rich DNA sequences.These structures have been found to play a crucial role in highly transcribed genes,especially in cancer-related oncogenes,making them attractive targets for cancer therapeutics.Significantly,targeting oncogene promoter G4 structures has emerged as a promising strategy to address the challenge of undruggable and drug-resistant proteins,such as MYC,BCL2,KRAS,and EGFR.Natural products have long been an important source of drug discovery,particularly in the fields of cancer and infectious diseases.Noteworthy progress has recently been made in the discovery of naturally occurring DNA G4-targeting drugs.Numerous DNA G4s,such as MYC-G4,BCL2-G4,KRAS-G4,PDGFR-b-G4,VEGF-G4,and telomeric-G4,have been identified as potential targets of natural products,including berberine,telomestatin,quindoline,sanguinarine,isaindigotone,and many others.Herein,we summarize and evaluate recent advancements in natural and nature-derived DNA G4 binders,focusing on understanding the structural recognition of DNA G4s by small molecules derived from nature.We also discuss the challenges and opportunities associated with developing drugs that target DNA G4s.

Buxu Tongyu Granule Alleviates Myocardial Ischemia by Activating Vascular Smooth Muscle Cell Soluble Guanylate Cyclase to Inhibit Abnormal Vasomotion

Myocardial ischemia is a serious threat to human health,and vascular dysfunction is its main cause.Buxu Tongyu(BXTY)Granule is an effective traditional Chinese medicine(TCM)for treating myocardial ischemia.However,the underlying mechanism of BXTY is still unclear.In this study,we demonstrate that BXTY ameliorates myocardial ischemia by activating the soluble guanylate cyclase(sGC)-30,50-cyclic guanosine monophosphate(cGMP)-protein kinase G(PKG)signaling pathway in vascular smooth muscle cells(VSMCs)to dilate the arteries.BXTY was given by gavage for ten consecutive days before establishing an animal model of acute myocardial ischemia in mice via the intraperitoneal injection of pituitrin.The results showed that BXTY alleviated the symptoms of myocardial ischemia induced by pituitrin in mice,including electrocardiogram abnormalities and changes in plasma enzymes.In addition,BXTY dilated pre-constricted blood vessels and inhibited the vasoconstriction of the superior mesenteric artery in a dose-dependent but endothelial-independent manner.These effects were eliminated by preincubating vascular rings with the sGC inhibitors NS 2028 or ODQ,or with the PKG inhibitor KT 5823.Moreover,BXTY increased the protein expression of sGC-b1 and the intracellular second messenger cGMP level in mouse aortic vascular smooth muscle cells(MOVAs).NS 2028 or ODQ reversed these effects of BXTY.The expression level of the cGMP downstream effector protein PKG-1 increased after treating MOVAs with BXTY.NS 2028,ODQ,or KT 5823 also reversed this effect of BXTY.In conclusion,BXTY can improve the symptoms of acute myocardial ischemia in mice,and activating the sGC-cGMP-PKG pathway in VSMCs to induce vasodilation is its key pharmacodynamic mechanism.

Medicinal chemistry strategies in the discovery and optimization of HBV core protein allosteric modulators(2018-2022 update)

Despite the improving coverage of preventative vaccines,hepatitis B remains a severe global public health problem,with more than 250 million patients living with hepatitis B virus(HBV)infection.Current available therapies,including nucleos(t)ide analogs and peginterferon,can control HBV replication but fail to eliminate covalently closed circular DNA(cccDNA)and achieve a cure.The HBV core protein(Cp)is a well-conserved structural protein,self-assembling to form the viral capsid.It involves in or modulates almost every stage of the HBV lifecycle,which makes it an attractive target for the development of new anti-HBV therapies.HBV core protein allosteric modulators(CpAMs)have become a hotspot in recent years.Herein,we provide a concise report focusing on the various medicinal chemistry strategies involved in the latest research(2018-2022)of HBV CpAMs,including high throughput screening(HTS),virtual screening(VS),drug repositioning,natural products,substitution decorating approach,scaffold hopping,molecular hybridization,prodrug strategy and conformational constraint strategy,to provide guidance for further development of new and effective anti-HBV drugs.

Neurocircuit regeneration by extracellular matrix reprogramming

The brain's extracellular matrix(ECM),which is comprised of protein and glycosaminoglycan(GAG)scaffolds,constitutes 20%-40% of the human brain and is considered one of the largest influencers on brain cell functioning(Soles et al.,2023).Synthesized by neural and glial cells,the brain's ECM regulates a myriad of homeostatic cellular processes,including neuronal plasticity and firing(Miyata et al.,2012),cation buffering(Moraws ki et al.,2015),and glia-neuron interactions(Anderson et al.,2016).Considering the diversity of functions,dynamic remodeling of the brain's ECM indicates that this understudied medium is an active participant in both normal physiology and neurological diseases.

Systematic review and meta-analysis of Saccharomyces boulardii in adult patients

This article reviews the evidence for efficacy and safety of Saccharomyces boulardii(S.boulardii) for various disease indications in adults based on the peerreviewed,randomized clinical trials and pre-clinical studies from the published medical literature(Medline,Clinical Trial websites and meeting abstracts) between 1976 and 2009.For meta-analysis,only randomized,blinded controlled trials unrestricted by language were included.Pre-clinical studies,volunteer studies and uncontrolled studies were excluded from the review of efficacy and meta-analysis,but included in the systematic review.Of 31 randomized,placebo-controlled treatment arms in 27 trials(encompassing 5029 study patients),S.boulardii was found to be significantly efficacious and safe in 84% of those treatment arms.A meta-analysis found a significant therapeutic efficacy for S.boulardii in the prevention of antibiotic-associated diarrhea(AAD)(RR = 0.47,95% CI:0.35-0.63,P < 0.001).In adults,S.boulardii can be strongly recommended for the prevention of AAD and the traveler's diarrhea.Randomized trials also support the use of this yeast probiotic for prevention of enteral nutrition-related diarrhea and reduction of Heliobacter pylori treatment-related symptoms.S.boulardii shows promise for the prevention of C.difficile disease recurrences;treatment of irritable bowel syndrome,acute adult diarrhea,Crohn's disease,giardiasis,human immunodeficiency virus-related diarrhea;but more supporting evidence is recommended for these indications.The use of S.boulardii as a therapeutic probiotic is evidence-based for both efficacy and safety for several types of diarrhea.

Comparison of pediatric and adult antibiotic-associated diarrhea and Clostridium difficile infections

Antibiotic-associated diarrhea(AAD) and Clostridum difficile infections(CDI) have been well studied for adult cases, but not as well in the pediatric population. Whether the disease process or response to treatments differs between pediatric and adult patients is an important clinical concern when following global guidelines based largely on adult patients. A systematic review of the literature using databases Pub Med(June 3, 1978-2015) was conducted to compare AAD and CDI in pediatric and adult populations and determine significant differences and similarities that might impact clinical decisions. In general, pediatric AAD and CDI have a more rapid onset of symptoms, a shorter duration of disease and fewer CDI complications(required surgeries and extended hospitalizations) than in adults. Children experience more community-associated CDI and are associated with smaller outbreaks than adult cases of CDI. The ribotype NAP1/027/BI is more common in adults than children. Children and adults share some similar risk factors, but adults have more complex risk factor profiles associated with more co-morbidities, types of disruptive factors and a wider range of exposures to C. difficile in the healthcare environment. The treatment of pediatric and adult AAD is similar(discontinuing or switching the inciting antibiotic), but other treatment strategies for AAD have not been established. Pediatric CDI responds better to metronidazole, while adult CDI responds better to vancomycin. Recurrent CDI is not commonly reported for children. Prevention for both pediatric and adult AAD and CDI relies upon integrated infection control programs, antibiotic stewardship and may include the use of adjunctive probiotics. Clinical presentation of pediatric AAD and CDI are different than adult AAD and CDI symptoms. These differences should be taken into account when rating severity of disease and prescribing antibiotics.

Naturally derived anti-hepatitis B virus agents and their mechanism of action

Despite that some approved drugs and genetically engineered vaccines against hepatitis B virus(HBV)are available for HBV patients,HBV infection is still a severe public health problem in the world.All the approved therapeutic drugs(including interferonalpha and nucleoside analogues)have their limitations.No drugs or therapeutic methods can cure hepatitis B so far.Therefore,it is urgently needed to discover and develop new anti-HBV drugs,especially nonnucleoside agents.Naturally originated compounds with enormous molecular complexity and diversity offer a great opportunity to find novel anti-HBV lead compounds with specific antiviral mechanisms.In this review,the natural products against HBV are discussed according to their chemical classes such as terpenes,lignans,phenolic acids,polyphenols,lactones,alkaloids and flavonoids.Furthermore,novel mode of action or new targets of some representative anti-HBV natural products are also discussed.The aim of this review is to report new discoveries and updates pertaining to anti-HBV natural products in the last 20years,especially novel skeletons and mode of action.Although many natural products with various skeletons have been reported to exhibit potent anti-HBV effects to date,scarcely any of them are found in the list of conventional anti-HBV drugs worldwide.Additionly,in anti-HBV mechanism of action,only a few references reported new targets or novel mode of action of antiHBV natural products.