1.Experimental study on the molluscicidal activity of surfactin against Oncomelania hupensis.
Chinese Journal of Schistosomiasis Control 2023;35(4):394-397
OBJECTIVE:
To evaluate the molluscicidal activity of surfactin against Oncomelania hupensis, so as to provide the experimental basis for use of Bacillus for killing O. hupensis.
METHODS:
O. hupensis snails were collected from schistosomiasisendemic foci of Wuhu City on September 2022, and Schistosoma japonicum-infected snails were removed. Then, 60 snails were immersed in surfactin at concentrations of 2, 1, 0.5, 0.25, 0.125 mg/mL and 0.062 5 mg/mL for 24, 48, 72 hours at 26 °C, while ultrapure water-treated snails served as controls. The median lethal concentration (LC50) of surfactin against O. hupensis snails was estimated. O. hupensis snails were immersed in surfactin at a concentration of 24 h LC50 and ultrapure water, and then stained with propidium iodide (PI). The PI uptake in haemocyte was observed in O. hupensis snails using fluorescence microscopy.
RESULTS:
The mortality of O. hupensis was 5.0% following immersion in surfactin at a concentration of 0.062 5 mg/mL for 24 h, and the mortality was 100.0% following immersion in surfactin at a concentration of 2 mg/mL for 72 h, while no snail mortality was observed in the control group. There were significant differences in the mortality of O. hupensis in each surfactin treatment groups at 24 (χ2 = 180.150, P < 0.05), 48 h (χ2 = 176.786, P < 0.05) and 72 h (χ2 = 216.487, P < 0.05), respectively. The average mortality rates of O. hupensis were 38.9% (140/360), 62.2% (224/360) and 83.3% (300/360) 24, 48 h and 72 h post-immersion in surfactin, respectively (χ2 = 150.264, P < 0.05), and the 24, 48 h and 72 h LC50 values of surfactin were 0.591, 0.191 mg/mL and 0.054 mg/mL against O. hupensis snails. Fluorescence microscopy showed more numbers of haemocytes with PI uptake in 0.5 mg/mL surfactintreated O. hupensis snails than in ultrapure water-treated snails for 24 h, and there was a significant difference in the proportion of PI uptake in haemocytes between surfactin-and ultrapure water-treated snails (χ2 = 6.690, P < 0.05).
CONCLUSIONS
Surfactin is active against O. hupensis snails, which may be associated with the alteration in the integrity of haemocyte membrane.
Animals
;
Molluscacides/pharmacology*
;
Snails
;
Schistosoma japonicum
;
Lethal Dose 50
;
Water
2.Characteristic profiles of biofilm, enterotoxins and virulence of Staphylococcus aureus isolates from dairy cows in Xinjiang Province, China
Yehui WU ; Jing LI ; Mengfan QIAO ; Dan MENG ; Qingling MENG ; Jun QIAO ; Xingxing ZHANG ; Lixia WANG ; Kuojun CAI ; Jinsheng ZHANG ; Zaichao ZHANG ; Weiwei YU ; Xuepeng CAI
Journal of Veterinary Science 2019;20(6):e74-
As an important zoonotic pathogen, Staphylococcus aureus has led to serious mastitis and endometritis in infected dairy cows. In this study, a total of 164 strains of S. aureus were isolated from dairy cows in Xinjiang Province, China, and subjected to assays to determine drug susceptibility and biofilm (BF) formation ability. Enterotoxin-related genes were detected, and the transcription levels of genes related to BF formation were determined by using reverse transcription-quantitative polymerase chain reaction. Moreover, the pathogenicity of isolates with different BF formation abilities was determined by measuring their hemolysis activity, half lethal dose (LD₅₀) and organ bacterial load. The results showed that 86.0% of S. aureus isolates could form BF. Among them, 42.1% of the strains had weak BF formation ability, and most strains with a strong BF formation ability were ica gene carriers. The S. aureus isolates displayed multidrug resistance and their drug resistance was positively correlated with their BF formation ability. Moreover, 96.3% of the S. aureus isolates carried enterotoxin genes. Among them, the detection rates of the novel enterotoxin genes were higher than those of conventional enterotoxin genes. Furthermore, isolates with a strong BF formation ability had higher LD50 but lower hemolysis ability and organ bacterial load than those of the isolates with weak or no BF ability. However, isolates without BF ability produced more severe pathological changes than those of isolates with strong BF formation ability. These findings suggest that higher BF ability and presence of novel enterotoxin genes are important characteristics of S. aureus isolates from dairy cows in Xinjiang Province, China, and such isolates may pose potential threats to food safety.
Bacterial Load
;
Biofilms
;
China
;
Drug Resistance
;
Drug Resistance, Microbial
;
Drug Resistance, Multiple
;
Endometritis
;
Enterotoxins
;
Female
;
Food Safety
;
Hemolysis
;
Lethal Dose 50
;
Mastitis
;
Polymerase Chain Reaction
;
Staphylococcus aureus
;
Staphylococcus
;
Virulence
3.Foeniculum vulgare as Valuable Plant in Management of Women's Health
Journal of Menopausal Medicine 2019;25(1):1-14
This review paper evaluates use of Foeniculum vulgare extracts as a popular female plant in management of different ailments of women. Information in this paper was gathered from accessible sources (PubMed, Science Direct, Springer, Wiley, and Google), and traditional books (Persian or English modern traditional books), unpublished data (R&D reports, thesis and dissertation) by keywords based on the words F. vulgare or fennel and women. Efficacy of oral fennel oil in management of dysmenorrhea, premenstrual syndrome, amenorrhea, menopause, lactation, and polycystic ovary syndrome were confirmed according to results of clinical studies. Results of clinical efficacy of fennel oil on menstrual bleeding is complicated, but results of one meta-analysis study revealed that fennel oil significantly increased means of bleeding in the first menstrual periodic cycle (P = 0.001), while fennel oil had no significant effect on bleeding in the second menstrual cycle (P = 0.67). Topical and vaginal fennel extract (5%) exhibited good efficacy in treatment of sexual function, vaginal atrophy, and hirsutism. Fennel had no effect on bone density, or body mass index of menopause women. Results of clinical studies introduce fennel as a valuable medicinal plant in management of women's ailments, but understanding the mechanism of action could be the subject of future studies.
Amenorrhea
;
Atrophy
;
Body Mass Index
;
Bone Density
;
Dysmenorrhea
;
Female
;
Foeniculum
;
Hemorrhage
;
Hirsutism
;
Humans
;
Lactation
;
Lethal Dose 50
;
Menopause
;
Menstrual Cycle
;
Phytoestrogens
;
Plants
;
Plants, Medicinal
;
Polycystic Ovary Syndrome
;
Premenstrual Syndrome
;
Treatment Outcome
;
Women's Health
4.Sequential method for determining the maximum dose of mivacurium continuously infused for intraoperative neuromonitoring in thyroid surgery.
Yongjie CHEN ; Lianjun HUANG ; Yang LI ; Li TONG ; Xiaochen WANG ; Keshi HU ; Zeguo FENG
Journal of Southern Medical University 2018;38(12):1472-1475
OBJECTIVE:
To determine the maximum dose of continuously infused mivacurium for intraoperative neuromonitoring and observe its adverse effects in thyroid surgery.
METHODS:
Twenty-eight patients undergoing thyroid surgery with intraoperative neuromonitoring received continuous infusion of mivacurium at the initial rate of 5.43 μg?kg?min, and the infusion rate for the next patient was adjusted based on the response of the previous patient according to the results of neurological monitoring. The depth of anesthesia was maintained with sevoflurane and remifentanil during the surgery. The LD50 and 95% of mivacurium were calculated using Brownlee's up-and-down sequential method.
RESULTS:
The LD50 of continuously infused mivacurium was 8.94 μg?kg?min (95% : 8.89- 8.99 μg?kg?min) during thyroid surgery, which did not affect neurological function monitoring. Transient chest skin redness occurred after induction in 9 patients (32.1%). None of the patients experienced intubation difficulties or showed intraoperative body motions during the surgery.
CONCLUSIONS
In patients undergoing thyroid surgery under anesthesia maintained by inhalation and intravenous infusion, the LD50 of mivacurium was 8.94 μg?kg?min (95% : 8.89-8.99 μg?kg?min) for continuous infusion, which does not cause serious adverse effects during the operation.
Anesthesia
;
Anesthetics, Inhalation
;
Anesthetics, Intravenous
;
Humans
;
Intraoperative Neurophysiological Monitoring
;
methods
;
Lethal Dose 50
;
Mivacurium
;
administration & dosage
;
adverse effects
;
Neuromuscular Nondepolarizing Agents
;
administration & dosage
;
adverse effects
;
Remifentanil
;
Sevoflurane
;
Thyroid Gland
;
surgery
5.Evaluation of acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. in Wistar rats.
Jeremiah Oshiomame UNUOFIN ; Gloria Aderonke OTUNOLA ; Anthony Jide AFOLAYAN
Journal of Integrative Medicine 2018;16(5):335-341
OBJECTIVEThis study investigated the acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. (AEVM) in rats for evaluating its safety profile.
METHODSAEVM for the acute (2000 and 5000 mg/kg) and subacute (200, 400 and 600 mg/kg) toxicity studies was administered orally to rats according the guidelines 425 and 407 of Organization for Economic Cooperation and Development, respectively. Food and water intake as well as body and organ weight of animals were recorded. Signs of toxicity were assessed, and hematological, biochemical and histopathological analyses were performed.
RESULTSIn the acute toxicity study, a single dose of the aqueous extract at 2000 or 5000 mg/kg caused no mortality in the animals, suggesting that the median lethal dose is greater than 5000 mg/kg. In the subacute toxicity study, administration of the extract for 28 d, at all doses, caused no significant changes in the body weights or organ weights of rats in the treated groups when compared with the control group. In addition, hematological and biochemical parameters also revealed no toxic effects of the extract on rats. Histological sections of the heart, liver and kidney from test animals showed no signs of degeneration.
CONCLUSIONThese results showed that AEVM at dosage levels up to 600 mg/kg is nontoxic and could also offer protection on some body tissues. AEVM could, therefore, be considered safe.
Animals ; Female ; Heart ; drug effects ; Kidney ; drug effects ; Lethal Dose 50 ; Liver ; drug effects ; Male ; Plant Extracts ; toxicity ; Plant Leaves ; Rats, Wistar ; Toxicity Tests, Acute ; Toxicity Tests, Subacute ; Vernonia ; toxicity
6.Antibacterial and Pharmacological Evaluation of Fluoroquinolones: A Chemoinformatics Approach.
Damini SOOD ; Neeraj KUMAR ; Aarushi SINGH ; Meena Kishore SAKHARKAR ; Vartika TOMAR ; Ramesh CHANDRA
Genomics & Informatics 2018;16(3):44-51
Fluoroquinolone (FQ) antibiotics are an important class of synthetic antibacterial agents. These are the most extensively used drugs for treating bacterial infections in the field of both human and veterinary medicine. Herein, the antibacterial and pharmacological properties of four fluoroquinolones: lomefloxacin, norfloxacin, ciprofloxacin, and ofloxacin have been studied. The objective of this study was to analyze the antibacterial characteristics of the different fluoroquinolones. Also, the pharmacological properties of the compounds including the Lipinski rule of five, absorption, distribution, metabolism, and excretion, LD50, drug likeliness, and toxicity were evaluated. We found that among all four FQ molecules, ofloxacin showed the highest antibacterial activity through in silico assays with a strong interaction (−38.52 kJ/mol) with the antibacterial target protein (topoisomerase-II DNA gyrase enzyme). The pharmacological and pharmacokinetic analysis also showed that the compounds ciprofloxacin, ofloxacin, lomefloxacin and norfloxacin have good pharmacological properties. Notably, ofloxacin was found to possess an IGC50 (concentration needed to inhibit 50% growth) value of 0.286 μg/L against the Tetrahymena pyriformis protozoa. It also tested negative for the Ames toxicity test, showing its non-carcinogenic character.
Absorption
;
Anti-Bacterial Agents
;
Bacterial Infections
;
Ciprofloxacin
;
Computer Simulation
;
DNA Gyrase
;
Fluoroquinolones*
;
Humans
;
Lethal Dose 50
;
Metabolism
;
Norfloxacin
;
Ofloxacin
;
Tetrahymena pyriformis
;
Toxicity Tests
;
Veterinary Medicine
7.A serine/threonine phosphatase 1 of Streptococcus suis type 2 is an important virulence factor.
Lihua FANG ; Jingjing ZHOU ; Pengcheng FAN ; Yunkai YANG ; Hongxia SHEN ; Weihuan FANG
Journal of Veterinary Science 2017;18(4):439-447
Streptococcus suis is regarded as one of the major pathogens of pigs, and Streptococcus suis type 2 (SS2) is considered a zoonotic bacterium based on its ability to cause meningitis and streptococcal toxic shock-like syndrome in humans. Many bacterial species contain genes encoding serine/threonine protein phosphatases (STPs) responsible for dephosphorylation of their substrates in a single reaction step. This study investigated the role of stp1 in the pathogenesis of SS2. An isogenic stp1 mutant (Δstp1) was constructed from SS2 strain ZJ081101. The Δstp1 mutant exhibited a significant increase in adhesion to HEp-2 and bEnd.3 cells as well as increased survival in RAW264.7 cells, as compared to the parent strain. Increased survival in macrophage cells might be related to resistance to reactive oxygen species since the Δstp1 mutant was more resistant than its parent strain to paraquat-induced oxidative stress. However, compared to parent strain virulence, deletion of stp1 significantly attenuated virulence of SS2 in mice, as shown by the nearly double lethal dose 50 value and the lower bacterial load in organs and blood in the murine model. We conclude that Stp1 has an essential role in SS2 virulence.
Animals
;
Bacterial Load
;
Humans
;
Lethal Dose 50
;
Macrophages
;
Meningitis
;
Mice
;
Oxidative Stress
;
Parents
;
Phosphoprotein Phosphatases
;
Reactive Oxygen Species
;
Streptococcus suis*
;
Streptococcus*
;
Swine
;
Virulence*
8.Biodistribution and Postmortem Redistribution of Emamectin Benzoate in Intoxicated Mice.
Wei-wei TANG ; Yu-cai LIN ; Yan-xu LU
Journal of Forensic Medicine 2016;32(1):26-30
OBJECTIVE:
To investigate the lethal blood level, the target organs and tissues, the toxicant storage depots and the postmortem redistribution in mice died of emamectin benzoate poisoning.
METHODS:
The mice model of emamectin benzoate poisoning was established via intragastric injection. The main poisoning symptoms and the clinical death times of mice were observed and recorded dynamically in the acute poisoning group as well as the sub-acute poisoning death group. The pathological and histomorphological changes of organs and tissues were observed after poisoning death. The biodistribution and postmortem redistribution of emamectin benzoate in the organs and tissues of mice were assayed by the enzyme-linked immunosorbent assay (ELISA) at 0h, 24h, 48h and 72h after death. The lethal blood concentrations and the concentrations of emamectin benzoate were detected by high performance liquid chromatography (HPLC) at different time points after death.
RESULTS:
The symptoms of nervous and respiratory system were observed within 15-30 min after intragastric injection. The average time of death was (45.8 ± 7.9) min in the acute poisoning group and (8.0 ± 1.4) d in the sub-acute poisoning group, respectively. The range of acute lethal blood level was 447.164 0-524.463 5 mg/L. The pathological changes of the organs and tissues were observed via light microscope and immunofluorescence microscope. The changes of emamectin benzoate content in the blood, heart, liver, spleen, lung, kidney and brain of poisoning mice showed regularity within 72 h after death (P < 0.05).
CONCLUSION
The target organs of emamectin benzoate poisoning include heart, liver, kidney, lung, brain and contact position (stomach). The toxicant storage depots are kidney and liver. There is emamectin benzoate postmortem redistribution in mice.
Animals
;
Autopsy
;
Chromatography, High Pressure Liquid
;
Dose-Response Relationship, Drug
;
Enzyme-Linked Immunosorbent Assay
;
Ivermectin/toxicity*
;
Lethal Dose 50
;
Mice
;
Postmortem Changes
;
Tissue Distribution
9.Toxic potential of palytoxin.
Jiří PATOCKA ; Ramesh C GUPTA ; Qing-hua WU ; Kamil KUCA
Journal of Huazhong University of Science and Technology (Medical Sciences) 2015;35(5):773-780
This review briefly describes the origin, chemistry, molecular mechanism of action, pharmacology, toxicology, and ecotoxicology of palytoxin and its analogues. Palytoxin and its analogues are produced by marine dinoflagellates. Palytoxin is also produced by Zoanthids (i.e. Palythoa), and Cyanobacteria (Trichodesmium). Palytoxin is a very large, non-proteinaceous molecule with a complex chemical structure having both lipophilic and hydrophilic moieties. Palytoxin is one of the most potent marine toxins with an LD50 of 150 ng/kg body weight in mice exposed intravenously. Pharmacological and electrophysiological studies have demonstrated that palytoxin acts as a hemolysin and alters the function of excitable cells through multiple mechanisms of action. Palytoxin selectively binds to Na(+)/K(+)-ATPase with a Kd of 20 pM and transforms the pump into a channel permeable to monovalent cations with a single-channel conductance of 10 pS. This mechanism of action could have multiple effects on cells. Evaluation of palytoxin toxicity using various animal models revealed that palytoxin is an extremely potent neurotoxin following an intravenous, intraperitoneal, intramuscular, subcutaneous or intratracheal route of exposure. Palytoxin also causes non-lethal, yet serious toxic effects following dermal or ocular exposure. Most incidents of palytoxin poisoning have manifested after oral intake of contaminated seafood. Poisonings in humans have also been noted after inhalation, cutaneous/systemic exposures with direct contact of aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing Cnidarian zoanthids. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide.
Acrylamides
;
chemistry
;
isolation & purification
;
toxicity
;
Animals
;
Anthozoa
;
pathogenicity
;
physiology
;
Dinoflagellida
;
pathogenicity
;
physiology
;
Dogs
;
Guinea Pigs
;
Haplorhini
;
Humans
;
Lethal Dose 50
;
Marine Toxins
;
chemistry
;
isolation & purification
;
toxicity
;
Mice
;
Rabbits
;
Rats
;
Seaweed
;
pathogenicity
;
physiology
;
Shellfish Poisoning
;
physiopathology
;
Sodium-Potassium-Exchanging ATPase
;
metabolism
10.Biological activities and acute oral toxicity of citronella and lemongrass oil.
Ji Yong PARK ; Jin Yoon KIM ; Seung Hee JANG ; Hae Jung KIM ; Seung Jin LEE ; Seung Chun PARK
Korean Journal of Veterinary Research 2015;55(1):13-20
This study was performed to investigate the antibacterial, antioxidant, and termite repellent effects of citronella oil (CiO) and lemongrass oil (LO). When the antibacterial activity against Staphylococcus (S.) aureus with various levels of antibacterial resistance were tested, a 0.05% concentration of CiO and LO completely inhibited the growth of all tested S. aureus strains. Evaluation of the antioxidant effect demonstrated that the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of CiO was 2~3 times greater than that of LO. Among trial products made with various combinations of CiO and LO, a CiO : LO ratio of 6 : 4 had the most potent termite repellent effects. Assessment of acute toxicity of the trial product showed that the LD50 was more than 2,000 mg/kg. Based on the above results, CiO and LO have antibacterial, antioxidant, and termite repellent activities. Therefore, both compounds could be potential termites repellent reagents.
Antioxidants
;
Cymbopogon*
;
Indicators and Reagents
;
Isoptera
;
Lethal Dose 50
;
Staphylococcus

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