Magnetic Fluorescent Quantum Dots Nanocomposites in Food Contaminants Analysis: Current Challenges and Opportunities.

The presence of food contaminants can cause foodborne illnesses, posing a severe threat to human health. Therefore, a rapid, sensitive, and convenient method for monitoring food contaminants is eagerly needed. The complex matrix interferences of food samples and poor performance of existing sensing probes bring significant challenges to improving detection performances. Nanocomposites with multifunctional features provide a solution to these problems. The combination of the superior characteristics of magnetic nanoparticles (MNPs) and quantum dots (QDs) to fabricate magnetic fluorescent quantum dots (MNPs@QDs) nanocomposites are regarded as an ideal multifunctional probe for food contaminants analysis. The high-efficiency pretreatment and rapid fluorescence detection are concurrently integrated into one sensing platform using MNPs@QDs nanocomposites. In this review, the contemporary synthetic strategies to fabricate MNPs@QDs, including hetero-crystalline growth, template embedding, layer-by-layer assembly, microemulsion technique, and one-pot method, are described in detail, and their advantages and limitations are discussed. The recent advances of MNPs@QDs nanocomposites in detecting metal ions, foodborne pathogens, toxins, pesticides, antibiotics, and illegal additives are comprehensively introduced from the perspectives of modes and detection performances. The review ends with current challenges and opportunities in practical applications and prospects in food contaminants analysis, aiming to promote the enthusiasm for multifunctional sensing platform research.

CMAS and ST3GAL4 Play an Important Role in the Adsorption of Influenza Virus by Affecting the Synthesis of Sialic Acid Receptors.

Influenza A viruses (IAVs) initiate infection by attaching Hemagglutinin (HA) on the viral envelope to sialic acid (SA) receptors on the cell surface. Importantly, HA of human IAVs has a higher affinity for α-2,6-linked SA receptors, and avian strains prefer α-2,3-linked SA receptors, whereas swine strains have a strong affinity for both SA receptors. Host gene CMAS and ST3GAL4 were found to be essential for IAV attachment and entry. Loss of CMAS and ST3GAL4 hindered the synthesis of sialic acid receptors, which in turn prevented the adsorption of IAV. Further, the knockout of CMAS had an effect on the adsorption of swine, avian and human IAVs. However, ST3GAL4 knockout prevented the adsorption of swine and avian IAV and the impact on avian IAV was more distinct, whereas it had no effect on the adsorption of human IAV. Collectively, our findings demonstrate that knocking out CMAS and ST3GAL4 negatively regulated IAV replication by inhibiting the synthesis of SA receptors, which also provides new insights into the production of gene-edited animals in the future.

Resistant cutoff values and optimal scheme establishments for florfenicol against Escherichia coli with PK-PD modeling analysis in pigs.

Florfenicol, a structural analog of thiamphenicol, has broad-spectrum antibacterial activity against gram-negative and gram-positive bacteria. This study was conducted to investigate the epidemiological, pharmacokinetic-pharmacodynamic cutoff, and the optimal scheme of florfenicol against Escherichia coli (E. coli) with PK-PD integrated model in the target infectious tissue. 220 E. coli strains were selected to detect the susceptibility to florfenicol, and a virulent strain P190, whose minimum inhibitory concentration (MIC) was similar to the MIC50 (8 µg/ml), was analyzed for PD study in LB and ileum fluid. The MIC of P190 in the ileum fluid was 0.25 times lower than LB. The ratios of MBC/MIC were four both in the ileum and LB. The characteristics of time-killing curves also coincided with the MBC determination. The recommended dosages (30 mg/kg·body weight) were orally administrated in healthy pigs, and both plasma and ileum fluid were collected for PK study. The main pharmacokinetics (PK) parameters including AUC24 hr , AUC0-∞ , Tmax , T1/2 , Cmax , CLb, and Ke were 49.83, 52.33 µg*h/ml, 1.32, 10.58 hr, 9.12 µg/ml, 0.50 L/hr*kg, 0.24 hr-1 and 134.45, 138.71 µg*hr/ml, 2.05, 13.01 hr, 16.57 µg/ml, 0.18 L/hr*kg, 0.14 hr-1 in the serum and ileum fluid, respectively. The optimum doses for bacteriostatic, bactericidal, and elimination activities were 29.81, 34.88, and 36.52 mg/kg for 50% target and 33.95, 39.79, and 42.55 mg/kg for 90% target, respectively. The final sensitive breakpoint was defined as 16 µg/ml. The current data presented provide the optimal regimens (39.79 mg/kg) and susceptible breakpoint (16 µg/ml) for clinical use, but these predicted data should be validated in the clinical practice.

Tilmicosin enteric granules and premix to pigs: Antimicrobial susceptibility testing and comparative pharmacokinetics.

The purpose of this study was to compare the pharmacokinetics and relative bioavailability of tilmicosin enteric granules and premix after oral administration at a dose of 40 mg/kg in pigs. Three kinds of different respiratory pathogens were selected for determination of minimal inhibitory concentration (MIC) to tilmicosin. Eight healthy pigs were assigned to a two-period, randomized crossover design. A modified rapid, sensitive HPLC method was used for determining the concentrations of tilmicosin in plasma. Pharmacokinetic parameters were calculated by using WinNonlin 5.2 software. The MIC90 of tilmicosin against Haemophilus parasuis, Actinbacillus pleuropneumoniae, and Pasteurella multocida were all 8 µg/ml. These results indicated that these common pig respiratory bacteria are sensitive to tilmicosin. The main parameters of time to reach maximum plasma concentration (Tmax ), elimination half-life (t1/2ß ), mean residence time (MRT), and apparent volume of distribution (VF ) were 2.03 ± 0.37 hr, 29.31 ± 5.56 hr, 25.22 ± 2.57 hr, 4.06 ± 1.04 L/kg, and 3.05 ± 0.08 hr, 17.06 ± 1.77 hr, 15.55 ± 1.37 hr, 2.95 ± 0.62 L/kg after the orally administrated tilmicosin enteric granules and premix. The relative bioavailability of tilmicosin enteric granules to premix was 114.97 ± 7.19%, according to the AUC0-t values. These results demonstrated that tilmicosin enteric granules produced faster tilmicosin absorption, slower elimination, larger tissue distribution, and higher bioavailability compared to the tilmicosin premix. The present study results manifest that tilmicosin enteric granules can be used as a therapeutic alternative to premix in clinical treatment.

Sus scrofa miR-204 and miR-4331 Negatively Regulate Swine H1N1/2009 Influenza A Virus Replication by Targeting Viral HA and NS, Respectively.

The prevalence of swine pandemic H1N1/2009 influenza A virus (SIV-H1N1/2009) in pigs has the potential to generate novel reassortant viruses, posing a great threat to human health. Cellular microRNAs (miRNAs) have been proven as promising small molecules for regulating influenza A virus replication by directly targeting viral genomic RNA. In this study, we predicted potential Sus scrofa (ssc-, swine) miRNAs targeting the genomic RNA of SIV-H1N1/2009 by RegRNA 2.0, and identified ssc-miR-204 and ssc-miR-4331 to target viral HA and NS respectively through dual-luciferase reporter assays. The messenger RNA (mRNA) levels of viral HA and NS were significantly suppressed when newborn pig trachea (NPTr) cells respectively overexpressed ssc-miR-204 and ssc-miR-4331 and were infected with SIV-H1N1/2009, whereas the suppression effect could be restored when respectively decreasing endogenous ssc-miR-204 and ssc-miR-4331 with inhibitors. Because of the importance of viral HA and NS in the life cycle of influenza A virus, ssc-miR-204 and ssc-miR-4331 exhibited an inhibition effect on SIV-H1N1/2009 replication. The antiviral effect was sequence-specific of SIV-H1N1/2009, for the target sites in HA and NS of H5N1 or H9N2 influenza A virus were not conserved. Furthermore, SIV-H1N1/2009 infection reversely downregulated the expression of ssc-miR-204 and ssc-miR-4331, which might facilitate the virus replication in the host. In summary, this work will provide us some important clues for controlling the prevalence of SIV-H1N1/2009 in pig populations.

Expression and biochemical characterization of recombinant human epididymis protein 4.

Whey acidic proteins (WAP) belong to a large gene family of antibacterial peptides that perform critical immune system functions. The function of human epididymis protein 4 (HE4), a 124-amino acid long polypeptide that has two whey acidic protein four-disulfide core (WFDC) domains, is not well studied. Here, a fusion gene encoding the HE4 protein fused to an IgG1 Fc domain was constructed. The recombinant HE4 protein was expressed as a secretory protein in Pichia pastoris and mammalian HEK293-F cells and was subsequently purified. Our data suggested that the HE4 protein produced by these two expression systems bound to both gram-negative and gram-positive bacteria, but demonstrated slightly inhibitory activity towards the growth of Staphylococcus aureus. Moreover, HE4 exhibited proteinase inhibitory activity towards trypsin, elastase, matrix metallopeptidase 9, and the secretory proteinases from Bacillus subtilis. The effects of glycosylation on the biochemical characterization of HE4 were also investigated. LC-ESI-MS glycosylation analysis showed that the high-mannose glycosylated form of HE4 expressed by P. pastoris has lower biological activity when compared to its complex-glycosylated form produced from HEK293-F cells. The implications of this are discussed, which may be provide theoretical basis for its important role in the development of cancer and innate immune system.

Highly efficient production of peptides: N-glycosidase F for N-glycomics analysis.

Peptide: N-glycosidase F (PNGase F) is an asparagine amidase produced by Flavobacterium meningosepticum that serves as a useful tool in the research on protein N-glycosylation. However, native PNGase F purified from F. meningosepticum and recombinant PNGase F expressed in Escherichia coli are obtained only at low levels, with the culture yield being no more than 15mg/L. Here, we report the efficient production of large amounts of recombinant PNGase F. First, a codon-optimized sequence encoding F. meningosepticum PNGase F was cloned into the pPICZaA vector, which was used to transform Pichia pastoris GS115. Clones were screened directly by dot blotting with an anti-6His-tag antibody, and then protein expression was induced in glass tubes to conduct validation assays. The clone expressing the highest level of PNGase F was selected for fermentation at a 5-L scale, and then the recombinant enzyme produced was purified in a single step using affinity chromatography, which yielded 800mg of the protein per liter of culture. The partly glycosylated recombinant PNGase F exhibited an identical specific activity as commercially available PNGase F when using RNase B or other N-glycoproteins as substrates. Thus, the method developed in this study can facilitate the large-scale production and use of PNGase F in the rapidly developing research field of N-glycomics.

Genetic characterization of H1N2 swine influenza virus isolated in China and its pathogenesis and inflammatory responses in mice.

In 2009, two H1N2 influenza viruses were isolated from trachea swabs of pigs in Hubei in China. We compared these sequences with the other 18 complete genome sequences of swine H1N2 isolates from China during 2004 to 2010 and undertook extensive analysis of their evolutionary patterns. Six different genotypes - two reassortants between triple reassortant (TR) H3N2 and classical swine (CS) H1N1 virus, three reassortants between TR H1N2, Eurasian avian-like H1N1 swine virus and H9N2 swine virus, and one reassortant between H1N1, H3N2 human virus and CS H1N1 virus - were observed in these 20 swine H1N2 isolates. The TR H1N2 swine virus is the predominant genotype, and the two Hubei H1N2 isolates were located in this cluster. We also used a mouse model to examine the pathogenesis and inflammatory responses of the two isolates. The isolates replicated efficiently in the lung, and exhibited a strong inflammatory response, serious pathological changes and mortality in infected mice. Given the role that swine can play as putative "genetic mixing vessels" and the observed transmission of TR H1N2 in ferrets, H1N2 influenza surveillance in pigs should be increased to minimize the potential threat to public health.

Molecular characteristics of the porcine TIMD4 gene and its association analysis.

As a member of the T cell immunoglobulin domain and mucin domain (TIM) gene family, TIMD4 plays an important role in the immune response. To understand its function more precisely, we isolated it and analyzed its subcellular localization, expression pattern, and associations. The porcine TIMD4 gene included nine exons and eight introns with an open reading frame of 1086 bp encoding 361 amino acids. It had relatively high levels in liver, lymph, and spleen. The fusion protein was localized mainly in the cytoplasm of pig kidney cells (PK15). The promoter region contained a TATA box and GATA3 consensus sites. A single nucleotide polymorphism was identified in intron 3 of the porcine TIMD4 gene, and analysis indicated that it had significant associations with the 17-day red blood cell count (p = 0.0106), hemoglobin (p = 0.0149), and hematocrit (p = 0.0063) and with 32-day hemoglobin (p = 0.0140).

Reaction temperature alters chorzoxazone metabolism in carp (Cyprinus carpio) hepatic microsomes.

The study aimed to study the influence of different reaction temperatures on the carp (Cyprinus carpio) hepatic CYPs activity. Six groups of carp hepatic microsomes were incubated with probe drug (chorzoxazone) at 5, 10, 15, 20, 25 and 30°C separately. According to the principle of enzyme kinetics theory, the Michaelis constant (K (m)) value and maximum reaction velocity (V (max)) of CYPs (with CZX as probe) were obtained. The CYPs activity at different reaction temperatures was compared. In results, the K (m) values were separately 44.62, 31.35, 26.59, 21.75, 16.39, 29.69 µM, and the V (max) were separately 0.231, 0.234, 0.265, 0.294, 0.315, 0.239 nmol min(-1)mg(-1) at 5, 10, 15, 20, 25, 30°C. Results indicated that the enzyme CYPs activity was much higher at 25°C. It was also demonstrated that reaction temperature could affect the CYPs activity significantly. Therefore, this experiment builded a theoretical basis for the variations of fish pharmacokinetic parameters at different water temperatures and contributed to further research on the influence of water temperature on fish drug metabolism.

Molecular characterization of Tob1 in muscle development in pigs.

Cell proliferation is an important biological process during myogenesis. Tob1 encoded a member of the Tob/BTG family of anti-proliferative proteins. Our previous LongSAGE (Long Serial Analysis of Gene Expression) analysis suggested that Tob1 was differentially expressed during prenatal skeletal muscle development. In this study, we isolated and characterized the swine Tob1 gene. Subsequently, we examined Tob1 chromosome assignment, subcellular localization and dynamic expression profile in prenatal skeletal muscle (33, 65 and 90 days post-conception, dpc) from Landrace (lean-type) and Tongcheng pigs (obese-type). The Tob1 gene was mapped to pig chromosome 12 (SSC12). The Tob1 protein was distributed throughout the nucleus and cytoplasm of PK15 cells. During prenatal skeletal muscle development, Tob1 was up-regulated and highly expressed in skeletal muscle at 90 dpc in Tongcheng pigs but peaked at 65 dpc in Landrace pigs. This result suggested that there were different proliferation patterns during myogenesis between Tongcheng and Landrace pigs. During postnatal skeletal muscle development, the expression of Tob1 increased with aging, indicating that the proliferation potential of myoblasts decreased in postnatal muscle development. In tissues of adult wuzhishan miniature pigs, the Tob1 gene was highly expressed in skeletal muscle. The expression of Tob1 was significantly increased at day 6 during C2C12 differentiation time, suggesting a possible role in skeletal muscle development. Therefore, this study indicated that Tob1 perhaps played an important role in skeletal muscle development.

Differential expression and correlation analysis of miRNA-mRNA profiles in swine testicular cells infected with porcine epidemic diarrhea virus.

The variant virulent porcine epidemic diarrhea virus (PEDV) strain (YN15) can cause severe porcine epidemic diarrhea (PED); however, the attenuated vaccine-like PEDV strain (YN144) can induce immunity in piglets. To investigate the differences in pathogenesis and epigenetic mechanisms between the two strains, differential expression and correlation analyses of the microRNA (miRNA) and mRNA in swine testicular (ST) cells infected with YN15, YN144, and mock were performed on three comparison groups (YN15 vs Control, YN144 vs Control, and YN15 vs YN144). The mRNA and miRNA expression profiles were obtained using next-generation sequencing (NGS), and the differentially expressed (DE) (p-value < 0.05) mRNA and miRNA were obtained using DESeq R package. mRNAs targeted by DE miRNAs were predicted using the miRanda algortithm. 8039, 8631 and 3310 DE mRNAs, and 36, 36, and 22 DE miRNAs were identified in the three comparison groups, respectively. 14,140, 15,367 and 3771 DE miRNA-mRNA (targeted by DE miRNAs) interaction pairs with negatively correlated expression patterns were identified, and interaction networks were constructed using Cytoscape. Six DE miRNAs and six DE mRNAs were randomly selected to verify the sequencing data by real-time relative quantitative reverse transcription polymerase chain reaction (qRT-PCR). Based on bioinformatics analysis, we discovered the differences were mostly involved in host immune responses and viral pathogenicity, including NF-κB signaling pathway and bacterial invasion of epithelial cells, etc. This is the first comprehensive comparison of DE miRNA-mRNA pairs in YN15 and YN144 infection in vitro, which could provide novel strategies for the prevention and control of PED.

Optimisation of the Conversion and Extraction of Arctigenin From Fructus arctii Into Arctiin Using Fungi.

Fructus arctii is commonly used in Chinese medicine, and arctiin and arctigenin are its main active ingredients. Arctiin has low bioavailability in the human body and needs to be converted into arctigenin by intestinal microbes before it can be absorbed into the blood. Arctigenin has antiviral, anti-inflammatory, and anti-tumour effects and its development has important value. In this study, we used external microbial fermentation with Aspergillus awamori and Trichoderma reesei to process and convert arctiin from F. arctii powder into arctigenin, hence increasing its bioavailability. We developed a fermentation process by optimising the carbon and nitrogen source/ratio, fermentation time, pH, liquid volume, inoculation volume, and substrate solid-liquid ratio. This allowed for an arctiin conversion rate of 99.84%, and the dissolution rate of the final product was 95.74%, with a loss rate as low as 4.26%. After the fermentation of F. arctii powder, the average yield of arctigenin is 19.51 mg/g. Crude fermented F. arctii extract was purified by silica gel column chromatography, and we observed an arctigenin purity of 99.33%. Our technique effectively converts arctiin and extracts arctigenin from F. arctii and provides a solid basis for further development and industrialisation.

Activation of reactive oxygen species-mediated mitogen-activated protein kinases pathway regulates both extrinsic and intrinsic apoptosis induced by arctigenin in Hep G2.

OBJECTIVES: Arctigenin (ARG) has been proved to inhibit the viability of hepatocellular carcinoma (HCC) via inducing apoptosis. However, the precise mechanism remains unknown. The present study was aimed to further investigate the mechanism of ARG against HCC in vitro and in vivo. METHODS: Arctigenin was applied in vitro and in vivo. Western blotting, immunohistochemistry, etc., were used to investigate the mechanisms. KEY FINDINGS: The time-dependent enhancement of Bax/Bcl-2 ratio, cytochrome c release, Fas and FasL levels, caspase cascade activation and the loss in the mitochondrial out membrane potential indicated that both intrinsic and extrinsic apoptotic pathways were triggered by ARG. Moreover, Jun NH2-terminal kinase (JNK) and p38 phosphorylated time-dependently. And inhibition of the phosphorylation of either p38 or JNK led to a significant reduction in HepG2 apoptosis, owing to the crucial roles of p38 and JNK played in regulating the apoptosis pathways. In addition, ARG increased the generation of reactive oxygen species (ROS) in HepG2 cells, while the antioxidant N-acetyl cysteine almost reversed ARG-induced JNK and p38 activation, and dramatically decreased cell apoptosis. In vivo, ARG increased the cell apoptosis in tumour tissues, and p-p38, p-JNK and Bax were significantly upregulated. CONCLUSIONS: Our findings demonstrated that ARG induced apoptosis in HCC via ROS-mediated mitogen-activated protein kinases apoptosis pathway.

Pharmacokinetics of Arctigenin and Fructus Arctii Powder in Piglets.

Fructus arctii, also known as great power seed, is the dried fruit of Arctium lappa of the family Compositae. It is a commonly used veterinary herbal medicine, and arctigenin is the main active ingredient. The aim of this study was to characterize the absorption, distribution, metabolism, and excretion of arctigenin and Fructus arctii powder in piglets. These data were used to provide a theoretical reference for the development and clinical use of new veterinary drugs. Sixteen healthy piglets (mean weight 30.0 ± 5.0 kg) were divided into two groups. One group was administered 2.0 mg/kg body weight (bw) arctigenin intravenously, and the other was administered 1.0 g/kg.bw Fructus arctii powder by gavage. Blood samples were collected from the anterior vena cava at different time points, and the concentration of arctigenin in the plasma of the piglets was determined using high-performance liquid chromatography (HPLC). Arctigenin conformed to a two-compartment model with no absorption, and the main pharmacokinetic parameters were as follows: distribution half-life (t 1/2α)-0.166 ± 0.022 h; elimination half-life (t 1/2ß)-3.161 ± 0.296 h; apparent volume of distribution (V d)-0.231 ± 0.033 L/kg; clearance rate (CLb)-0.057 ± 0.003 L/(h.kg); and area under the curve (AUC)-1.189 ± 0.057 g.h/mL. The pharmacokinetic parameters of arctigenin following oral administration of the Fructus arctii powder were as follows: absorption half-life (t 1/2ka)-0.274 ± 0.102 h, t 1/2α-1.435 ± 0.725 h, t 1/2ß-63.467 ± 29.115 h, V d-1.680 ± 0.402 L/kg, CLb-0.076 ± 0.028 L/(h kg), peak time (t max)-0.853 ± 0.211 h, peak concentration (C max)-0.430 ± 0.035 g/mL, and AUC-14.672 ± 4.813 g/mL. These results indicated that intravenous arctigenin was sparingly distributed in tissues. In contrast, orally administered Fructus arctii powder was rapidly absorbed, more widely distributed, and more slowly eliminated than the intravenous arctigenin, which may indicate its sustained pharmacological effects.

The pharmacokinetic-pharmacodynamic modeling and cut-off values of tildipirosin against Haemophilus parasuis.

The goal of this study was to establish the epidemiological, pharmacodynamic cut-off values, optimal dose regimens for tildipirosin against Haemophilus parasuis. The minimum inhibitory concentrations (MIC) of 164 HPS isolates were determined and SH0165 whose MIC (2 µg/ml ) were selected for PD analysis. The ex vivo MIC in plasma of SH0165 was 0.25 µg/ml which was 8 times lower than that in TSB. The bacteriostatic, bactericidal and elimination activity (AUC24h/MIC) in serum were 26.35, 52.27 and 73.29 h based on the inhibitory sigmoid Emax modeling. The present study demonstrates that 97.9% of the wild-type (WT) isolates were covered when the epidemiological cut-off value (ECV) was set at 8 µg/ml. The parameters including AUC24h, AUC, T1/2, Cmax, CLb and MRT in PELF were 19.56, 60.41, 2.32, 4.02, 56.6, and 2.63 times than those in plasma, respectively. Regarding the Monte Carlo simulation, the COPD was defined as 0.5 µg/ml in vitro, and the optimal doses to achieve bacteriostatic, bactericidal and elimination effect were 1.85, 3.67 and 5.16 mg/kg for 50% target, respectively, and 2.07, 4.17 and 5.78 mg/kg for 90% target, respectively. The results of this study offer a more optimised alternative for clinical use and demonstrated that 4.17 mg/kg of tildipirosin by intramuscular injection could have an effect on bactericidal activity against HPS. These values are of great significance for the effective treatment of HPS infections, but it also be deserved to be validated in clinical practice in the future research.

Corrigendum: Evaluation of Marbofloxacin in Beagle Dogs After Oral Dosing: Preclinical Safety Evaluation and Comparative Pharmacokinetics of Two Different Tablets.

[This corrects the article on p. 306 in vol. 9, PMID: 29692725.].

Bioequivalence evaluation of two 5% ceftiofur hydrochloride sterile suspension in pigs.

The purpose of this study was to evaluate the bioequivalence of 5% ceftiofur hydrochloride sterile suspension in two formulations, a test formulation (Saifukang 5% CEF, Hvsen) and a reference formulation (Excenel®RTU 5% CEF, Pfizer). Twenty-four healthy pigs were assigned to a two-period, two-treatment crossover parallel trial, and both formulations were administered at a single intramuscular dose of 5 mg/kg weight, with a 7-day washout period. Blood samples were collected consecutively for up to 144 hr after administration. The concentrations of ceftiofur- and desfuroylceftiofur-related metabolites in the plasma were determined by high-performance liquid chromatography. In addition, the major pharmacokinetic parameters (Cmax, AUC0-t and AUC0-∞) were computed and compared via analysis of variance, with 90% confidence intervals. Bioequivalence evaluation of Tmax was statistically analyzed with the nonparametric test. The comparison values between test and reference formulation for AUC0-t, AUC0-∞, Cmax, and Tmax were 376.7 ± 75.3 µg·hr/ml, 390.5 ± 78.6 µg·hr/ml, 385.9 ± 79.2 µg·hr/ml, 402.7 ± 80.4 µg·hr/ml, 34.6 ± 5.5 µg/ml, 36.1 ± 6.2 µg/ml, 1.27 ± 0.18 hr, and 1.26 ± 0.21 hr, respectively, and we observed no significant differences between the two formulations. The 90% CI values were within the recommended range of 80-125% (P>0.05), and the relative bioavailability of the test product was 96.47 ± 10.92% according to AUC0-t values. Based on our results, the two formulations exhibit comparable pharmacokinetic profiles, and the test product is bioequivalent to the reference formulation.

Evaluation of Marbofloxacin in Beagle Dogs After Oral Dosing: Preclinical Safety Evaluation and Comparative Pharmacokinetics of Two Different Tablets.

The current study evaluates a tested marbofloxacin tablet (MBT) (Petsen), in terms of bioavailability and pharmacokinetics (PK) in a comparison of the commercialized and standard tablet (Marbocyl) in beagle dogs. Four different bacterial species were selected for the determination of the minimal inhibitory concentration (MIC) against marbofloxacin (MBF). Target animal safety studies were conducted with a wide spectrum of dosages of Petsen. Pharmacokinetics and bioavailability of Petsen were observed after the oral administration of a recommended dosage of 2 mg/kg. The MIC90 of MBF against Staphylococcus aureus, Escherichia coli, Pasteurella multocida, and Streptococcus were 2.00, 4.00, 0.25, and 0.50 µg/ml, respectively. These results showed that the MBT has an expected antimicrobial activity in vitro. The main parameters of t1/2ß, Clb, AUC0-∞, Cmax, and Ke were 22.14 h, 0.15 L/h, 13.27 µg.h/ml, 0.95 µg/ml, 0.09 h-1, and 16.47 h, 0.14 L/h, 14.10 µg.h/ml, 0.97 µg/ml, 0.11 h-1 after the orally administrated Petsen and Marbocyl, while no biologically significant changes and toxicological significance have been found by their comparison. These findings indicate that the Petsen had a slow elimination, high bioavailability and kinetically similar to the commercialized Marbocyl. Furthermore, no statistically significant differences were distinguished on the continuous gradient dosages of 2, 6, and 10 mg/kg in the term of the clinical presentation. The present study results displayed that the tested MBT (Petsen) was safe, with limited toxicity, which was similar to the commercialized tablet (Marbocyl), could provide an alternative MBT as a veterinary medicine in beagle dogs.

Comparative Pharmacokinetics and Preliminary Pharmacodynamics Evaluation of Piscidin 1 Against PRV and PEDV in Rats.

Antimicrobial peptide (Piscidin-1) is an effective natural polypeptide, which has great influence and potential on porcine epidemic diarrhea virus (PEDV) and pseudorabies virus (PRV). As an alternative antibiotic substitute, Piscidin-1 was subjected for pharmacokinetics study with three administration routes (i.v, i.m, and p.o) after a single dose of 2 mg/kg in rats and preliminary pharmacodynamics including antiviral activity in cell against PEDV and PRV. Based on 50 percent tissue culture infective dose (TCID50), there were about 2 and 10% virus survived ratios for Piscidin-1 against PRV and PEDV, respectively. The plaque test showed 1 and 2 µg/ml Piscidin-1 could eliminate 95% PRV and 85% PEDV, respectively. The main pharmacokinetics parameters of Cmax, AUC0-∞, Ke, t1/2, Tmax, MRT, and Clb in plasma were not applicable value, 25.9 µg*h/ml, 0.041 h-1, 16.97 h, not available value, 22.77 h, 0.067 L/h*kg after i.v administration, 2.37 µg/ml, 18.95 µg*h/ml, 0.029 h-1, 23.50 h, 0.33 h, 30.12 h, 0.095 L/h*kg after i.m administration and 0.73 µg/ml, 9.63 µg*h/ml, 0.036 h-1, 19.46 h, 0.50 h, 26.76 h, 0.171 L/h*kg after p.o administration. The bioavailability values after i.m and p.o administrations were calculated as 73.17 and 37.18%, respectively. The i.m administration was selected for pharmacokinetics study in ileum content against PEDV. The main pharmacokinetic parameters of Cmax, AUC0-∞, Ke, t1/2, Tmax, MRT, and Clb in ileum content were 1.67 µg/ml, 78.40 µg*h/ml, 0.034 h-1, 20.16 h, 8.12 h, 36.45 h, 0.026 L/h*kg. The Cmax values in plasma (2.37 µg/ml) and ileum content (1.67 µg/ml) were higher than the effective inhibitory concentration determined in the plaque test, and this indicates that Piscidin-1 might have effective inhibition effect against PRV and PEDV after administration of 2 mg/kg i.m. The results of this study represent the first investigations toward the pharmacokinetic characteristics of piscidin-1 in plasma upon three different administration routes, among which i.m. resulted in the highest bioavailability (73.17%). Furthermore, the pharmacokinetics study of ileum content indicated Piscidin-1 might have good effect against PEDV and could be regarded as an alternative antibiotic in clinical veterinary in the future study.