LD50 Values Research Articles

The Effect of Two Novel Substituted Thiazole and Thiadiazine Derivatives on Experimental Type-1 Diabetes Mellitus

Thiazole and thiadiazine derivatives are heterocyclic compounds containing nitrogen and sulfur. They have a wide range of medicinal applications. The present study aimed to investigate the anti-hyperglycemic and antioxidant properties of two novel thiazole and thiadiazine derivatives using streptozotocin (STZ)-induced diabetic mice. The two synthesized compounds significantly reduced hyperglycemia and restored pancreatic insulin secretion in the treated diabetic mice. Also, the two compounds lead to a decrease in the serum triglyceride level and an increase in pancreatic SOD activity in the treated diabetic mice. The LD50 value of the two compounds using the IP injection route was greater than 300 mg/kg body weight. Further studies on these two compounds, especially mechanisms of action, are required to develop them into potential anti-diabetic drugs.

Cheminformatics approach to identify andrographolide derivatives as dual inhibitors of methyltransferases (nsp14 and nsp16) of SARS-CoV-2

The Covid-19 pandemic outbreak has accelerated tremendous efforts to discover a therapeutic strategy that targets severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to control viral infection. Various viral proteins have been identified as potential drug targets, however, to date, no specific therapeutic cure is available against the SARS-CoV-2. To address this issue, the present work reports a systematic cheminformatic approach to identify the potent andrographolide derivatives that can target methyltransferases of SARS-CoV-2, i.e. nsp14 and nsp16 which are crucial for the replication of the virus and host immune evasion. A consensus of cheminformatics methodologies including virtual screening, molecular docking, ADMET profiling, molecular dynamics simulations, free-energy landscape analysis, molecular mechanics generalized born surface area (MM-GBSA), and density functional theory (DFT) was utilized. Our study reveals two new andrographolide derivatives (PubChem CID: 2734589 and 138968421) as natural bioactive molecules that can form stable complexes with both proteins via hydrophobic interactions, hydrogen bonds and electrostatic interactions. The toxicity analysis predicts class four toxicity for both compounds with LD50 value in the range of 500–700 mg/kg. MD simulation reveals the stable formation of the complex for both the compounds and their average trajectory values were found to be lower than the control inhibitor and protein alone. MMGBSA analysis corroborates the MD simulation result and showed the lowest energy for the compounds 2734589 and 138968421. The DFT and MEP analysis also predicts the better reactivity and stability of both the hit compounds. Overall, both andrographolide derivatives exhibit good potential as potent inhibitors for both nsp14 and nsp16 proteins, however, in-vitro and in vivo assessment would be required to prove their efficacy and safety in clinical settings. Moreover, the drug discovery strategy aiming at the dual target approach might serve as a useful model for inventing novel drug molecules for various other diseases.

Comparing Sensitivity of Different Bee Species to Pesticides: A TKTD modeling approach.

Risk assessment for bees is mainly based on data for honey bees; however, risk assessment is intended to protect all bee species. This raises the question of whether data for honey bees are a good proxy for other bee species. This issue is not new and has resulted in several publications in which the sensitivity of bee species is compared based on the values of the 48-h median lethal dose (LD50) from acute test results. When this approach is used, observed differences in sensitivity may result both from differences in kinetics and from inherent differences in species sensitivity. In addition, the physiology of the bee, like its overall size, the size of the honey stomach (for acute oral tests), and the physical appearance (for acute contact tests) also influences the sensitivity of the bee. The recently introduced Toxicokinetic-Toxicodynamic (TKTD) model that was developed for the interpretation of honey bee tests (Bee General Uniform Threshold Model for Survival [BeeGUTS]) could integrate the results of acute oral tests, acute contact tests, and chronic tests within one consistent framework. We show that the BeeGUTS model can be calibrated and validated for other bee species and also that the honey bee is among the more sensitive bee species. In addition, we found that differences in sensitivity between species are smaller than previously published comparisons based on 48-h LD50 values. The time-dependency of the LD50 and the specifics of the bee physiology are the main causes of the wider variation found in the published literature. Environ Toxicol Chem 2024;43:1431-1441. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Determination of lethal dose (LD50) and sensitivity of fenugreek (Trigonella foenum-graecum) to sodium azide for induction of mutation

The present experiment was conducted in the year 2021 at Sri Karan Narendra Agriculture University, Jobner, Rajasthan, to determine the optimum dose (LD50) and duration of the chemical mutagen treatment for the induction of desirable mutation. A set of 100 pre-soaked fenugreek seeds were treated with 12 different concentrations of sodium azide, viz. 0.3 mM, 0.6 mM, 1 mM, 2 mM, 3 mM, 4 mM, 5 mM, 6 mM, 7 mM, 8 mM, 9 mM and 10 mM for three different durations, viz. 3 h, 6 h and 9 h. Results showed that a dose-dependent decreasing tendency was observed in germination percentage, survival percentage, root length and shoot length with increasing concentration and duration of sodium azide treatment. Almost all the mutagenic treatments resulted in decrease in germination percentage, survival percentage and seedling height (root and shoot length) with increasing concentrations and duration of mutagen in laboratory conditions. Also, the LD50 value was observed as an 8 mM sodium azide concentration for 6 h in fenugreek. The mutagen treatments given at 9 h duration were detrimental for fenugreek. They cannot be used for mutation induction as they are utterly lethal after a 3 mM sodium azide concentration. So, lower treatments of mutagens have influenced less biological damage and would be suitable for inducing desirable mutations.

Insecticidal Activity of Essential Oils and Their Synergistic Effect on Improving the Efficacy of β-Cypermethrin against Blattella germanica.

We screened the contact activity of 32 commercial essential oils (EOs) and their synergistic effect with β-cypermethrin against Blattella germanica. Results showed that the most effective EOs against B. germanica were from Illicium verum, Syzygium aromaticum, and Cinnamomum camphora, with LD50 values of less than 500 μg/insect. The most potent synergistic effects of β-cypermethrin on B. germanica were from Dysphania ambrosioides and Mentha canadensis. Both oils have a co-toxic factor of 133.33. The results of the major compound testing of the EOs showed that trans-anisaldehyde and thymol have the best insecticidal activity against B. germanica, with LD50 values of 141.30 and 138.61 μg/insect, respectively. The compounds with the best synergistic effect on β-cypermethrin were γ-terpinene and linalool at a concentration of 0.5%. The co-toxic factors for γ-terpinene and linalool were 150 and 133.33, respectively, which were similar to the synergistic effect observed with 2% piperonyl butoxide.

Safety, Analgesic, and Anti-Inflammatory Effects of Aqueous and Methanolic Leaf Extracts of Hypericum revolutum subsp. keniense

In light of the enduring obstacles encountered in analgesia and anti-inflammatory therapeutics despite the strides made in contemporary medical sciences, the quest for alternative efficacious strategies is an imperative pursuit. Thus, this study investigated the safety profiles, as well as the analgesic and anti-inflammatory attributes, of aqueous and methanolic leaf extracts derived from Hypericum revolutum subsp. keniense—a botanical entity entrenched in historical ethnomedicinal practices in the Kenyan context. The assessment of acute oral toxicity of these extracts was conducted in accordance with the Up- and-Down method advocated by the Organisation for Economic Cooperation and Development (OECD), utilizing Swiss albino mice as the experimental subjects. Subsequent investigation entailed the evaluation of antinociceptive and anti-inflammatory properties employing the acetic acid-induced writhing and carrageenan-induced paw oedema methodologies, respectively, in the same murine model. The findings of this study evince the safety of both aqueous and methanolic extracts, with LD50 values surpassing 2000 mg/kg body weight and the absence of discernible signs of toxicity. Furthermore, a notable dose-dependent (P<0.05) manifestation of analgesic effects was observed for both extracts, with the aqueous variant demonstrating heightened potency compared to its methanolic counterpart (P<0.05). Moreover, the anti-inflammatory efficacy escalated significantly with escalating extract doses and prolonged treatment duration (P<0.05), wherein the aqueous extract showcased superior effectiveness vis- à-vis the methanolic extract across all dosage regimens and temporal checkpoints (P<0.05). Therefore, this investigation underscores the latent promise of the examined extracts as reservoirs of safe and efficacious analgesic and anti-inflammatory agents, thereby meriting further meticulous exploration. Subsequent research endeavours ought to pivot towards elucidating the phytochemical constituents underpinning the observed effects, alongside unravelling their mechanistic underpinnings across a spectrum of animal models and clinical milieus.

Evaluation on the traditional safe use of Kochiae Fructus oriented by antioxidant properties and oral safety of its ethanolic extract

Kochiae Fructus (KF) is a traditional Chinese medicine, which has been used to delay aging and treat inflammation, such as rubella, eczema, cutaneous pruritus, etc. In order to fully understand the traditional medicinal value of KF, we evaluated the antioxidant properties and oral safety of its ethanolic extract. Considering flavonoids and phenolics in medicinal plants generally have strong antioxidant activity, we firstly detected the total flavonoids and phenolics contents of KFEE and its fractions. Secondly, we evaluated the antioxidant activities of KFEE and its fractions. Finally, we evaluated the oral safety of KFEE by the acute and 28-day subacute toxicities. The n-butanol fraction (ENBF) possessed the highest phenolics and flavonoids with values of 77.30 ± 3.17 mg gallic acid equivalents/g and 228.81 ± 7.56 mg rutin equivalents/g, respectively. The results of antioxidant tests showed that ENBF possessed potent antioxidant ability. Among them, the high antioxidation capacity observed in ENBF could be attributed to its rich content of flavonoids and phenolics. The results of toxicological studies showed that the LD50 value of KFEE was 6000 mg/kg BW, and the no observed adverse effect level (NOAEL) of KFEE was 600 mg/kg BW. According to the standards of the American Academy of Sciences for the classification of toxic substances, KFEE can be classified as practically non-toxic substance, which provided valuable evidence for the oral safety of KF as a natural aging delay medicine.

Alocasia macrorrhiza rhizome lectin inhibits growth of pathogenic bacteria and human lung cancer cell in vitro and Ehrlich ascites carcinoma cell in vivo in mice

Cancer and antibiotic resistance represent significant global challenges, affecting public health and healthcare systems worldwide. Lectin, a carbohydrate-binding protein, displays various biological properties, including antimicrobial and anticancer activities. This study focused on anticancer and antibacterial properties of Alocasia macrorrhiza lectin (AML). AML, with a molecular weight of 11.0 ± 1.0 kDa was purified using Ion-exchange chromatography, and the homotetrameric form was detected by gel-filtration chromatography. It agglutinates mouse erythrocytes, that was inhibited by 4-Nitrophenyl-α-d-mannopyranoside. Maximum hemagglutination activity was observed below 60 °C and within a pH range from 8 to 11. Additionally, it exhibited moderate toxicity against brine shrimp nauplii with LD50 values of 321 μg/ml and showed antibacterial activity against Escherichia coli and Shigella dysenteriae. In vitro experiments demonstrated that AML suppressed the proliferation of mice Ehrlich ascites carcinoma (EAC) cells by 35 % and human lung cancer (A549) cells by 40 % at 512 μg/ml concentration. In vivo experiments involved intraperitoneal injection of AML in EAC-bearing mice for five consecutive days at doses of 2.5 and 5.0 mg/kg/day, and the results indicated that AML inhibited EAC cell growth by 37 % and 54 %, respectively. Finally, it can be concluded that AML can be used for further anticancer and antibacterial studies.

Edwarsiella ictaluri: Pathogenicity and LD50 in Pangasius nasutus

This study focuses on pathogenicity and LD50 of Pangasius nasutus against Edwardsiella ictaluri. Pangasius nasutus or ‘patin buah’ is a native freshwater species of peninsular Malaysia and can be found in Pahang River. The market price for this species is high as it tastes better compared to other catfish. Edwardsiella ictaluri is a pathogenic bacteria and the causative agent that cause enteric septicemia of catfish (ESC) in the Pangasius species. However, the prevention measures against Edwardsiella ictaluri are still unknown for Pangasius nasutus due to the lack of research and study. Therefore, the objective of this study is to identify Edwardsiella ictaluri isolated from Pangasius nasutus cultured in Pahang River using polymerase chain reaction (PCR) and to determine the pathogenicity and LD50 of Pangasius nasutus against Edwardsiella ictaluri through injection method. There are four different concentrations of Edwardsiella ictaluri (1×1010, 1×109, 1×108, 1×107) that were injected intraperitoneally including normal saline water as control to a total of 50 Pangasius nasutus. Observation of clinical signs and mortality were carried out for 30 days and LD50 was determined. The earliest clinical sign was observed at concentration of 1×1010 cfu/ml at 2 hours post-infection of Edwardsiella ictaluri where pale liver and congested kidney can be observed after dissection. Other clinical signs observed are inflammation on tail and fin, hemorrhagic fin, hemorrhagic upper mandible, discoloration, and inflammation on the lower part of body. The first mortality of Pangasius nasutus was at concentration 1×1010 cfu/ml at 2 hours of post infection. The highest cumulative mortality was recorded at concentration 1×1010 cfu/ml with 100% of mortality rate. From the result, the value of LD50 of Edwardsiella ictaluri calculated was 1×106 cfu/ml. From this study, it can be concluded that Edwardsiella ictaluri does affect the survivability Pangasius nasutus in Malaysia.

Computational analysis of 3D printing: Selecting the better among newly released materials.

Resin-based three-dimensional (3D) printing finds extensive application in the field of dentistry. Although studies of cytotoxicity, mechanical and physical properties have been conducted for newly released 3D printing resins such as Crowntec (Saremco), Temporary Crown Resin (Formlabs) and Crown & Bridge (Nextdent), the resistance of these materials to esterases in saliva has not been demonstrated at the molecular level. Therefore, in this study, the binding affinities and stability of these new 3D printing resins to the catalytic sites of esterases were investigated using molecular docking and molecular mechanics with Poisson-Bolzmann and surface area solvation (MM/PBSA) methods after active pocket screening. Toxicity predictions of the materials were also performed using ProTox-II and Toxtree servers. The materials were analyzed for mutagenicity, cytotoxicity, and carcinogenicity, and LD50 values were predicted from their molecular structures. The results indicated that out of the three novel 3D printing materials, Nexdent exhibited reduced binding affinity to esterases, indicating enhanced resistance to enzymatic degradation and possessing a superior toxicity profile.

QseC regulates chemotaxis, biofilm formation, motility, and virulence in Aeromonas veronii TH0426

Aeromonas veronii is an important fish and human pathogen that causes significant economic losses in aquaculture. The two-component system QseBC has been shown to regulate virulence in various pathogens, but its functional role in A. veronii is unclear. In this study, we constructed in-frame deletion mutants of qseC in A. veronii TH0426 and complemented strains to determine the effects on pathogenesis-related phenotypes and global gene expression. Deletion of qseC did not significantly impact growth curves or colony morphology compared to wild-type A. veronii TH0426. However, the ΔqseC mutant displayed impaired swimming motility, with flagella staining and TEM images showing severe flagella detachment compared to intact flagella in wild-type cells. Crystal violet assays and confocal microscopy revealed that deletion of qseC significantly increased biofilm formation in A. veronii, with the ΔqseC mutant forming 2.07 times more biofilm than wild-type. Altered structural parameters indicative of increased heterogeneity were observed in the ΔqseC biofilm compared to wild-type using ISA analysis. Furthermore, the ΔqseC mutant showed enhanced adhesion to and invasion of epithelioma papulosum cyprini (EPC) cells in vitro. Using a zebrafish infection model, the ΔqseC mutant exhibited attenuated virulence with an 8.5-fold increase in LD50 value compared to wild-type A. veronii TH0426. Bacterial load enumeration in the blood, liver, spleen, and kidney of ΔqseC-infected carp over a 48-h period revealed significantly reduced bacterial counts compared to wild-type. In vivo competition assays indicated the ΔqseC mutant had reduced fitness in carp tissues compared to wild-type A. veronii. RNA sequencing revealed 2364 differentially expressed genes in the ΔqseC mutant compared to wild-type strain TH0426. KEGG pathway enrichment analysis indicated these genes were involved in chemotaxis, flagellar assembly, biofilm formation, protein secretion, and other pathways. Overall, this study demonstrates that QseC plays a vital regulatory role in controlling chemotaxis, flagellar motility, biofilm formation and virulence in the fish and human pathogen A. veronii.

Evaluation of in silico model predictions for mammalian acute oral toxicity and regulatory application in pesticide hazard and risk assessment

The United States Environmental Protection Agency (USEPA) uses the lethal dose 50% (LD50) value from in vivo rat acute oral toxicity studies for pesticide product label precautionary statements and environmental risk assessment (RA). The Collaborative Acute Toxicity Modeling Suite (CATMoS) is a quantitative structure-activity relationship (QSAR)-based in silico approach to predict rat acute oral toxicity that has the potential to reduce animal use when registering a new pesticide technical grade active ingredient (TGAI). This analysis compared LD50 values predicted by CATMoS to empirical values from in vivo studies for the TGAIs of 177 conventional pesticides. The accuracy and reliability of the model predictions were assessed relative to the empirical data in terms of USEPA acute oral toxicity categories and discrete LD50 values for each chemical. CATMoS was most reliable at placing pesticide TGAIs in acute toxicity categories III (>500–5000 mg/kg) and IV (>5000 mg/kg), with 88% categorical concordance for 165 chemicals with empirical in vivo LD50 values ≥ 500 mg/kg. When considering an LD50 for RA, CATMoS predictions of 2000 mg/kg and higher were found to agree with empirical values from limit tests (i.e., single, high-dose tests) or definitive results over 2000 mg/kg with few exceptions.

Milk protein polymorphisms and casein haplotypes in Blanco Orejinegro cattle of Colombia

The aim was to determine the genetic variation in the CSN1S1, CSN2, CSN1S2, CSN3 and LGB genes in Blanco Orejinegro cattle. 419 animals from 15 herds were genotyped with GGP Bovine 150 K (n= 70) and 50 K (n= 349) chips. Information was obtained from 43 SNPs in the mentioned genes and protein variants *B, *C and *D of αS1-CN; *A1, *A2, *B, *H2 and *F of β-CN; *A and *D of αS2-CN, *A, *A1, *B, *I and *H of κ-CN and *A, *B, *C, *D, *E, *F and *H of β-LG were reconstructed. Allele and genotypic frequencies were estimated for SNPs and for protein variants; Hardy-Weinberg equilibrium and FST values were evaluated for each of the SNPs under different structuring criteria. LD values and haplotypic frequencies were estimated for caseins. The most frequent variants were CSN1S1*B (0.804), CSN2*A2 (0.509), CSN1S2*A (0.997), CSN3*A (0.679) and β-LG*B (0.657). None of the variants showed deviations from HWE, but the CSN2*A2 allele showed a slight increasing trend over time. The FST values were low (0.035) regardless of the structuring criteria. Twenty-eight CSN1S1-CSN2-CSN1S2-CSN3 haplotypes were found, 22 of them with frequencies <5%; the three most frequent were BB-A1A2-AA-AA-AA-AA (16.6%), BB-A1A2-AA-AA-AA-AB (14.1%) and BB-A2A2-AA-AA-AA (10.1%). A good potential of BON cattle to produce high quality milk with functional value was reported.

The influence of eyelid pressure and eye contour factors on rigid corneal contact lens fitting

PurposeThis study aimed to investigate the impact of eyelid pressure (ELP) and eye contour factors on rigid corneal contact lens fitting. MethodsThis prospective cross-sectional study involved 20 participants (one eye per person). Rigid corneal contact lenses with three different base curves were selected for each participant. The base curves were calculated according to the average keratometry value. The original value and its variations (+0.1 mm and − 0.1 mm) were considered. Eye contour factors, lens decentration under natural eye position (LD I) and full eyelid exposure (LD II), and lens vertical movement were taken by a Canon camera mounted on a digital slit lamp biomicroscope. Upper and lower ELPs were measured by a novel blepharo-tensiometer. ResultsThe mean values of LD I, LD II, and lens vertical movement significantly increased as the base curve increased (P＜0.001, ＜0.001, and = 0.005). Upper ELP was positively correlated with lens vertical movement of the three base curves (P = 0.047, 0.001, and 0.004). Furthermore, upper ELP (odds ratio [OR]: 1.039; 95 % confidence [CI]: 1.009–1.069; P = 0.009) and flat keratometry values (OR: 0.873; 95 % CI: 0.786–0.969; P = 0.011) independently influenced lens vertical movement. ConclusionsELP and base curve independently influenced rigid corneal contact lens fitting. Thus, ELP should be considered during rigid corneal contact lens fitting in clinical practice.

Comparative toxicological-hygienic assessment, structural-morphological, physicochemical characteristics, and virucidal properties of new nanopowder materials TiO2 and TiO2@Ag

In order to address safety concerns related to the acquisition and utilization of TiO2 and TiO2@Ag nanomaterials, as well as to investigate their disinfectant and biological effects, the structural-morphological, morpho­metry, toxicological, cytotoxic, and virucidal properties of these specified nanomaterials have been studied through experiments conducted on laboratory animals and in vitro. It has been demonstrated that the TiO2@Ag nanocomposite exhibited distinct physicochemical characteristics: it consisted of TiO2 nanoparticles ranging in size from 13 nm to 20 nm and Ag nanoparticles ranging from 35 nm to 40 nm with 4.0 wt% of silver localized on the surface of titanium dioxide. The purity of the modification of synthesized nano-TiO2 and nano-TiO2@Ag has been confirmed. Acute intraperitoneal administration of nanopowders revealed LD50 values of 4783.30 mg/kg for nano-TiO2 and 724.44 mg/kg for nano-TiO2@Ag. A slight accumulation was observed upon repeated (28-fold) intragastric administration of nano-TiO2. The cumulative dose administered, which equated to 15.9 multiples of the LD50 (76040 mg/kg), did not result in animal mortality but led to retardation in body weight gain. TiO2 and TiO2@Ag nanopowders do not irritate the skin, induce mild conjunctival irritation, and may exhibit a weak sensitizing effect. Nano-TiO2 and nano-TiO2@Ag powders accumulate in the tissues of internal organs and cause damage to the liver, kidneys, and lungs of laboratory animals upon intraperitoneal administration. The most characteristic morphological signs of the toxic effect of nano-TiO2 on liver tissue were observed at a level of 67.7% (cytoplasmic vacuolization in hepatocytes), while in the case of nano-TiO2@Ag initial necrotic changes were at a level of 70.0% (hepatocytes with pyknotic nuclei). Immunoassay analysis has demonstrated that TiO2@Ag and TiO2 nanomaterials at concentrations of 30 µg/ml can enhance the functional activity of peripheral blood mononuclear cells in vitro by increasing the production of cytokines IL-1, IL-6, TNF-α, and IL-4 in donors (p<0.05). This indicates the potential for chronic inflammation and allergic reactions among synthesis operators. In the study of the impact of nanomaterials on murine germ cells, it has been established that they affect the activity of mitochondrial enzymes and exert a damaging effect on mitochondrial membranes and overall cell integrity. Estimated approximate safe exposure levels in the workplace air are 0.3 mg/m3 for nano-TiO2 and 0.2 mg/m3 for nano-TiO2@Ag. Nano-TiO2@Ag and nano-TiO2 at a concentration of 100 µg/ml exhibit pronounced extracellular virucidal activity against human adenovirus serotype 2. The TiO2@Ag nanocomposite has a less damaging effect on Нер-2 cells compared to nano-TiO2.

Evaluation of Medicago sativa ethanol leaf extract for antidiarrheal activity in Wistar rats

Aim: Medicago sativa leaf is traditionally used for the treatment of gastrointestinal disorders in Nigeria. This research investigates the in vivo antidiarrheal activity of M. sativa (Alfalfa) leaf extract in Wistar rats. Method: The study employed three models: castor oil-induced diarrhea, gastrointestinal motility (charcoal meal), and castor oil-induced intestinal fluid accumulation. The phytochemical analysis as well acute toxicity tests were carried out in the leaf extract. Results: The results demonstrate a dose-dependent and significant antidiarrheal effect of M. sativa leaf extract. In the castor oil-induced diarrhea model, the extract reduced fecal frequency, delayed onset, and lowered severity, with the highest effect at 600 mg/kg compared to a positive control (Loperamide). Gastrointestinal motility was inhibited by the extract in a dose-dependent manner, achieving maximum effect at 600 mg/kg, comparable to atropine sulfate. The castor oil-induced intestinal fluid accumulation model revealed a significant decrease in fluid volume at 600 mg/kg, exhibiting a potent inhibitory effect. The oral LD50 values obtained were greater than 5000 mg/kg in rats Conclusion: This study provides compelling evidence of Medicago sativa leaf extract's potential as an antidiarrheal agent in Wistar rats. Further investigations could explore its mechanism of action and safety profile, contributing valuable insights to the development of novel antidiarrheal therapies.

Pathogenicity of Aeromonas veronii Isolated from Diseased Macrobrachium rosenbergii and Host Immune-Related Gene Expression Profiles.

Aeromonas veronii is widespread in aquatic environments and is responsible for infecting various aquatic animals. In this study, a dominant strain was isolated from the hepatopancreas of diseased Macrobrachium rosenbergii and was named JDM1-1. According to its morphological, physiological, and biochemical characteristics and molecular identification, isolate JDM1-1 was identified as A. veronii. The results of artificial challenge showed isolate JDM1-1 had high pathogenicity to M. rosenbergii with an LD50 value of 8.35 × 105 CFU/mL during the challenge test. Histopathological analysis revealed severe damage in the hepatopancreas and gills of the diseased prawns, characterized by the enlargement of the hepatic tubule lumen and gaps between the tubules as well as clubbing and degeneration observed at the distal end of the gill filament. Eight virulence-related genes, namely aer, ompA, lip, tapA, hlyA, flgA, flgM, and flgN, were screened by PCR assay. In addition, virulence factor detection showed that the JDM1-1 isolate produced lipase, lecithinase, gelatinase, and hemolysin. Furthermore, the mRNA expression profiles of immune-related genes of M. rosenbergii following A. veronii infection, including ALF1, ALF2, Crustin, C-lectin, and Lysozyme, were assessed, and the results revealed a significant upregulation in the hepatopancreas and intestines at different hours post infection. This study demonstrates that A. veronii is a causative agent associated with massive die-offs of M. rosenbergii and contributes valuable insights into the pathogenesis and host defense mechanisms of A. veronii invasion.

A New Insight Into Toxicity of Database Compounds from Ginger (Zingiber officinale) by Modelling Study

Dengue haemorrhagic fever (DHF) is an infectious disease caused by the dengue virus. The dengue virus is transmitted through female mosquitoes, especially Aedes aegypti and Aedes albopictus. Indonesia is a dengue endemic country, and almost all provinces in Indonesia are infected with dengue. However, targeted antiviral drugs against dengue virus (DENV) are not yet available. This study aimed to determine the potential of three compounds isolated from ginger (Zingiber officinale) as dengue NS2B/NS3 inhibitors, and to predict the physicochemical properties (drug-likeness) and potential toxicity of drug candidates. Ginger isolates in the form of [8]-gingerol, [6]-paradol, shogaol were obtained from the Natural Discovery Database (NADI). Toxicity and drug-likeness predictions were performed using ProTox-II and SwissADME, and Molecular Operating Environment (MOE) 2022.0901 was used for the molecular docking process. Results: The results showed that the ginger compound (Zingiber officinale), [8]-Gingerol, [6]-Paradol, and Shogaol, had binding free energy of -7.18, -7.10 and -6.88 kcal/mol, respectively. It is indicated that three compounds had potentiality to inhibit the NS2B/NS3 protein complex with a binding free energy that was almost equivalent to that of the positive control, panduratin A, and similar to that of the positive control, which can be seen in superimposition. In addition, three compounds isolated from ginger met the drug-likeness parameters. Based on the analysis of in silico toxicity studies, the three compounds isolated from ginger showed different levels of toxicity. Therefore, based on the safety level of oral use, the [8]-gingerol compound is safer to develop as a dengue antiviral drug, where the LD50 value of [8]-gingerol is 2.580 mg/kg with a class V toxicity level that is practically nontoxic.

Detection of selective sweep in European wild sheep breeds.

In wild animal populations, there is a differentiation between populations due to natural selection. The direction and pressure of natural selection in the wild sheep are different in the various geographic areas. Linkage disequilibrium studies showed that regions of the genome in whole wild sheep are under natural selection and that natural selection can affect immune or reproductive or metabolic traits. The study aimed to identify genomic regions under natural selection in wild sheep. For this purpose, the genetic information of 24 European wild sheep and 24 Sardinian wild sheep was used. The genotypes were determined using Illumina 50K SNPChip arrays based on Oar_4.0 version of the sheep genome. After quality control steps, finally, 31,560 SNP markers were analyzed. The value of LD was calculated by calculating the r2 statistic between all pairs of locations through PLINK software. To identify signs of selection based on linkage disequilibrium methods, an extended haplotype homozygosity test of XP-EHH crossing population and iHS intrapopulation was used. The results of iHS studies showed that in European and Sardinian wild sheep, the highest iHS coefficient under natural selection was observed on 3 and 2 chromosome numbers, respectively. Also, the results of XP-EHH studies showed that the largest XP-EHH coefficients under natural selection in European wild sheep compared to Sardinian and vice versa in Sardinian wild sheep compared to European wild sheep were observed on 3 and 16 chromosome numbers, respectively. In addition, the results of gene cycle studies showed that COPB1, SEC24D, ZDHHC17, BBS4, RFX3, SLC26A8, CAMK2D, GRIA1, GRM1, GRID2, PPP2R1A, CPEB4, PLEKHA5 and KIF13A, VPS39, VPS53, DTNBP1, DYNC1I1, FAM91A genes are under natural selection in Sardinian and European wild sheeps, respectively. The direction and selection pressure of natural selection in the two breeds of wild sheep is different due to different geographic conditions.

Abstract 6015: Effect of antineoplastic drugs on cell-to-cell communication in the progression of colorectal cancer

Abstract Background: In the past few years, there has been notable progress in colorectal cancer research, resulting in novel development and delivery of drugs specifically designed for individual patient requirements. However, one of the major roadblocks in designing and treating colorectal cancer is the drug resistance found in advanced stages. Thus, there is a profound need to establish new methods to overcome this barrier. Previous work illustrated that cell-to-cell communications are dysfunctional for multitude of reasons in colorectal cancer cells. Restoration of cell-to-cell communication is a mean to deliver antineoplastic drugs via bystanding effect. Prior research has demonstrated that restoring gap junctions of cell-to-cell communication in breast cancer cells enhances the efficacy of cisplatin, a drug previously deemed resistant. Hence, this study seeks to assess the potency and efficacy of antineoplastic agents known to show resistance in colorectal cancer, with the intention to investigate how gap junctions can increase the efficacy of antineoplastic agents via restoration of cell-to-cell communication. Method: We assessed cell viability utilizing the RealTime Glo MT Cell Viability assay (Promega, Inc.). Four specific colorectal cancer cell lines, Caco2, HT-29, SW620, and SW480, were used. Four antineoplastic agents, doxorubicin, cediranib, nilotinib, and erlotinib, were selected for the study and subsequently in the combination study of gap junction enhancer. The lethal dose at 50% (LD50) was calculated for each antineoplastic agent in each cell line. Results: The results show significant variation of LD50. HT-29 cells dosed with doxorubicin showed LD50 of 8.9 µM, 1.6 µM, and 0.5 µM at 24 hours, 36 hours, and 48 hours of exposure, respectively. HT-29 cells dosed with erlotinib showed LD50 of 15.8 µM and 8.9 µM at 48 hours and 60 hours of exposure, respectively. SW620 dosed with doxorubicin showed LD50 is 0.5 µM at 36 hours of exposure. SW620 dosed with erlotinib showed LD50 of 15.8 µM and 0.5 µM at 48 hours and 60 hours of exposure, respectively. Caco2 cells dosed with cediranib showed LD50 of 2.8 µM and 1.6 µM at 36 hours and 48 hours of exposure, respectively. Conclusion: The findings from this study revealed varying LD50 values for these cell lines when treated with the four distinct drugs. This enabled us to determine a foundational effect of these drugs on these cell lines, which had not been previously identified. Discovering this foundational effect will allow us to investigate the synergy effect when combined with gap junction enhancer by setting a baseline effect using these results. Citation Format: Tomas Lugo, Annelise Nguyen. Effect of antineoplastic drugs on cell-to-cell communication in the progression of colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6015.