Antibacterial Mode of Action of the Essential Oil Obtained from Chamaecyparis obtusa Sawdust on the Membrane Integrity of Selected Foodborne Pathogens

U ovom je radu ispitan mehanizam antibakterijskog učinka esencijalnog ulja dobivenog iz piljevine pačempresa (Chamaecyparis obtusa) na patogene bakterije u hrani. Esencijalno je ulje dobiveno mikrovalnom ekstrakcijom i hidrodestilacijom piljevine pačempresa. Vrijednosti su minimalne inhibitorne koncentracije esencijalnog ulja što su sprečavale rast bakterija u hrani, poput Bacillus cereus ATCC 13061, Listeria monocytogenes ATCC 7644, Staphylococcus aureus ATCC 12600, Salmonella Typhimurium ATCC 43174 i Escherichia coli ATCC 43889, bile u rasponu od 62,5 do 500 μg/mL, a vrijednosti minimalne baktericidne koncentracije u rasponu od 125 do 1000 μg/mL. Potvrđeno je da je esencijalno ulje u minimalnoj inhibitornoj koncentraciji sprečavalo rast stanica ispitanih bakerija. Osim toga, pretražnom su elektronskom mikroskopijom pronađene bitne morfološke promjene ili puknuća stanične membrane bakterija B. cereus ATCC 13061 i E. coli ATCC 43889, čime je potvrđen inhibicijski utjecaj esencijalnog ulja iz piljevine pačempresa. Oslobađanje velikih količina izvanstaničnog adenozin 5’-trifosfata (ATP) i materijala koji se apsorbira na valnoj duljini od 260 nm, te gubitak iona kalija iz stanice negativno djeluju na Gram-pozitivnu bakteriju B. cereus ATCC 13061 i Gram-negativnu bakteriju E. coli ATCC 43889, što potvrđuje učinak esencijalnog ulja na staničnu membranu. Iz dobivenih se rezultata može zaključiti da esencijalno ulje dobiveno iz piljevine pačempresa ima antibakterijsku aktivnost širokog spektra, te da djeluje na integritet stanične membrane i morfološka svojstva bakterija izoliranih iz hrane.The present study examines the possible antibacterial mechanism of action of the essential oil obtained from Chamaecyparis obtusa (COEO) sawdust against foodborne pathogenic bacteria. The COEO was obtained by microwave-assisted hydrodistillation of C. obtusa sawdust. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of COEO against the tested foodborne pathogens including Bacillus cereus ATCC 13061, Listeria monocytogenes ATCC 7644, Staphylococcus aureus ATCC 12600, Salmonella Typhimurium ATCC 43174 and Escherichia coli ATCC 43889 were found in the range from 62.5 to 500 μg/mL and from 125 to 1000 μg/mL, respectively. At the MIC concentrations, the COEO had potential inhibitory effect on the cell viability of the tested bacteria. In addition, the scanning electron microscopic analysis confirmed the inhibitory effect of COEO by revealing significant morphological alterations or rupture of the cell membranes of B. cereus ATCC 13061 and E. coli ATCC 43889. Moreover, the mode of action of COEO on the cell membrane of both Gram-positive B. cereus ATCC 13061 and Gram-negative E. coli ATCC 43889 bacteria was confirmed by marked release of extracellular adenosine 5’-triphosphate (ATP) and cellular material that absorbs at 260 nm, and by efflux of potassium ions. These findings suggest that COEO holds a broad-spectrum antibacterial efficacy, confirming its influence on the membrane integrity and morphological characteristics of tested foodborne pathogens

SplitEE: Early Exit in Deep Neural Networks with Split Computing

Deep Neural Networks (DNNs) have drawn attention because of their outstanding performance on various tasks. However, deploying full-fledged DNNs in resource-constrained devices (edge, mobile, IoT) is difficult due to their large size. To overcome the issue, various approaches are considered, like offloading part of the computation to the cloud for final inference (split computing) or performing the inference at an intermediary layer without passing through all layers (early exits). In this work, we propose combining both approaches by using early exits in split computing. In our approach, we decide up to what depth of DNNs computation to perform on the device (splitting layer) and whether a sample can exit from this layer or need to be offloaded. The decisions are based on a weighted combination of accuracy, computational, and communication costs. We develop an algorithm named SplitEE to learn an optimal policy. Since pre-trained DNNs are often deployed in new domains where the ground truths may be unavailable and samples arrive in a streaming fashion, SplitEE works in an online and unsupervised setup. We extensively perform experiments on five different datasets. SplitEE achieves a significant cost reduction ($>50\%$) with a slight drop in accuracy ($<2\%$) as compared to the case when all samples are inferred at the final layer. The anonymized source code is available at \url{https://anonymous.4open.science/r/SplitEE_M-B989/README.md}.Comment: 10 pages, to appear in the proceeding AIMLSystems 202

A diterpenoid sugiol from Metasequoia glyptostroboides with α-glucosidase and tyrosinase inhibitory potential

Nowadays use of plant derived natural compounds have become a topic of increasing interest in food and medicine industries due to their multitude of biological and therapeutic properties. In this study, a diterpenoid compound sugiol, isolated from Metasequoia glyptostroboideswas evaluated for α-glucosidase and tyrosinase inhibitory efficacy in terms of its potent anti-diabetic and anti-melanogenesis potential, respectively. As a result, sugiol at the concentration range of (100-10,000 µg/mL) and (20-500 µg/mL) showed potent efficacy on inhibiting α-glucosidase and tyrosinase enzymes in vitro ranging from 12.34-63.47% and 28.22-67.43%, respectively. These findings confirm the therapeutic potential of diterpenoid compound sugiol from M. glyptostroboides as a novel candidate for using in food and medicine industry which may have practical potential to cure skin and diabetes mellitus type-2 related disorders

Isolation and preliminary characterization of a bacteriocin-producer Bacillus strain inhibiting methicillin resistant Staphylococcus aureus

In a multivalent approach to discover new antimicrobial substance, a total of 160 Bacilli were isolated from termitarium soil, characterized on the basis of their morphological and physiological characters and screened for their antimicrobial activity by agar well diffusion method against certain drug resistant pathogenic bacteria such as Staphylococcus aureus, Methicillin resistant Staphylococcus aureus and common food contaminating bacteria Listeria monocytogenes. After preliminary screening, sixteen isolates showed inhibitory activity against test pathogens. Among them Bacillus isolate TSH58 exhibited maximum inhibitory activity against MRSA, Staphylococcus aureus and Listeria monocytogenes. Based on morphological, physiological, biochemical and 16S rDNA characteristics isolate TSH58 was identified as a member of the Bacillus cereus species group. Various nutrient sources and culture conditions were optimized, the partially purified antimicrobial metabolite was subjected to various treatments such as heat, pH and proteolytic enzymes. Complete loss in the activity observed when the crude metabolite was treated with proteolytic enzymes suggesting its proteinaceous nature and termed as bacteriocin like inhibitory substance (BLIS). Minimal inhibitory concentration of the partially purified bacteriocin determined by microtiter plate assay was 80 μg/ml for MRSA and 40 μg/ml for L. monocytogenes. Tricine SDS PAGE analysis revealed that the partially purified bacteriocin produced by the Bacillus strain TSH58 had an apparent molecular weight of about 4.0 KDa

Experimental strategy of animal trial for the approval of anti-diabetic agents prior to their use in pre-human clinical trials

Although several naturally available drugs have been historically used for the treatment of diabetes mellitus throughout the world, few of them have been validated by scientific criteria. Before approval of any drug developed it should pass through animal trial prior to clinical human trial, which should followed by some standard ethical rules. Recently, a large diversity of animal models have been developed to better understand the pathogenesis of diabetes mellitus, and new drugs have been introduced in the market to treat this autoimmune disease. In the present article, we demonstrated some standard handling procedure of animal trial for the approval of anti-diabetic drug, which could be helpful for both academics and industrial scientific community to conduct the animal experiments. This research also contributes in the field of ethnopharmacology to design new strategies for the development of novel drugs to treat this serious condition of diabetes mellitus that constitutes a global public health. Video Clip of Methodology:  Handling and caring of mice: 2 min 30 sec   Full Screen   Alternate Inducing diabetes in mice and observing blood glucose level: 1 min 47 sec   Full Screen   Alternate Drug administration and observation of blood glucose level: 2 min 11 sec   Full Screen   Alternat

Imiquimod-induced psoriasis-like skin inflammation in mouse model

Psoriasis is a skin disorder characterized by skin inflammation and plaques. Induction of psoriasis in animal model include following steps: a) Selection of animal model, b) Hair removing from the back or ear, c) treatment of skin with Aldara, a cream containing 5% imiquimod and d) Observation. Imiquimod-induced skin inflammation in animal model resembles with psoriasis. Video Clip of Methodology: Psoriaisis-like skin: 9 min 10 sec   Full Screen   Alternat

Fenolni sastav i antioksidativna svojstva esencijalnog ulja dobivenog iz piljevine pačempresa mikrovalnom ekstrakcijom i hidrodestilacijom

Reactive oxygen species and free radicals play a major role in food deterioration. Current research is directed towards finding naturally occurring antioxidants of plant origin. In the present study, the chemical composition analysis of the essential oil obtained from sawdust of Chamaecyparis obtusa (COEO) was conducted by gas chromatography coupled with mass spectroscopy (GC-MS). Further, the phenolic content and antioxidant capacity of the COEO were investigated using different radical scavenging assays. The COEO obtained from the dried sawdust material using a microwave-assisted hydrodistillation technique resulted in the determination of 46 different compounds by GC-MS analysis, representing 98.94 % of total oil content. The COEO was characterised by the presence of mono- and sesquiterpene hydrocarbons, oxygenated mono- and sesquiterpenes, steroids, diterpenes and indole derivatives. At the highest tested concentration range, the COEO showed antioxidant capacity, i.e. the inhibition of DPPH, nitric oxide, superoxide and hydroxyl radicals of 80.16, 82.93, 72.99 and 71.62 %, respectively. Moreover, the COEO displayed concentration-dependent reducing power ability and remarkable inhibitory effect on ferric ion-induced lipid peroxidation in bovine brain extract. In addition, the COEO yielded (6.13±0.05) mg of gallic acid per g of dry mass. The present study confirms that the C. obtusa essential oil has potent antioxidant, lipid peroxidation inhibition and radical scavenging abilities; therefore, it might be used as a natural antioxidant to prevent food deterioration.Reaktivni spojevi kisika i slobodni radikali glavni su uzrok propadanja hrane, pa su najnovija istraživanja usmjerena na pronalazak prirodnih antioksidanasa biljnoga podrijetla. U ovom je radu plinskom kromatografijom i masenom spektrometrijom analiziran kemijski sastav esencijalnog ulja dobivenog iz piljevine pačempresa (Chamaecyparis obtusa). Udjel fenolnih spojeva i antioksidativna svojstva dobivenog ulja ispitani su pomoću različitih mehanizama uklanjanja slobodnih radikala. U esencijalnom je ulju pačempresa dobivenom mikrovalnom ekstrakcijom i hidrodestilacijom sušene piljevine pomoću plinske kromatografije i masene spektrometrije određeno 46 spojeva koji čine 98,94 % ukupnog sastava ulja. Ulje sadržava mono- i seskviterpene, oksigenizirane mono- i seskviterpene, steroide, diterpene i derivate indola. Pri najvećoj je koncentraciji esencijalno ulje pačempresa inhibiralo 80,16 % DPPH radikala, 82,93 % dušikovog monoksida, 72,99 % superoksida i 71,62 % hidroksilnih radikala. Osim toga, utvrđeno je da je reducirajuća snaga ulja ovisila o njegovoj koncentraciji, te da je ulje znatno inhibiralo peroksidaciju lipida kataliziranu ionima željeza(II) u goveđem ekstraktu. Ulje je sadržavalo (6,13±0,05) mg galne kiseline po gramu suhe tvari. Ovo istraživanje potvrđuje da esencijalno ulje pačempresa ima jaka antioksidativna svojstva, te dobru sposobnost inhibicije peroksidacije lipida i uklanjanja slobodnih radikala, pa se može upotrijebiti kao prirodni antioksidans u svrhu očuvanja svježine hrane

Antiviral mode of action of Lactobacillus plantarum YML009 on Influenza virus H1N1

The development of resistance against antiviral agents has augmented a threat to public health sector. Consequently there is an expanding demand for the development of unconventional antiviral agents that could efficiently replace the existent in-use drugs. The probiotic strains of lactic acid bacteria (LAB) have earned the status of being efficient, economical and safe nutraceutical in health care armamentarium. A total of 2272 LAB strains were screened against H1N1 virus. The isolate YML009 displayed a pronounced antiviral activity. Sequencing and biochemical assays identified the isolate as Lactoballius plantarum which, exhibited resistance to the damage caused by the acidic conditions such as gastric juice and 5% bile salt. The anti-H1N1 activity of the strain was confirmed by hemagglutination assay and was found to display enhanced efficacy in comparison to the commercially available antiviral drug. This is a primary report on anti-influenza activity of a bacterium L. plantarum YML009.