Low-dose thiram exposure elicits dysregulation of the gut microbial ecology in broiler chickens.

Thiram, a typical fungicide pesticide, is widely used in agricultural production. The presence of thiram residues is not only due to over-utilization, but is also primarily attributed to long-term accumulation. However, there is a paucity of information regarding the impact of prolonged utilization of thiram at low doses on the gut microbiota, particularly with respect to gut fungi. Our objective is to explore the effect of thiram on broilers from the perspective of gut microbiota, which includes both bacteria and fungi. We developed a long-term low-dose thiram model to simulate thiram residue and employed 16 S rRNA and ITS gene sequencing to investigate the diversity and profile of gut microbiota between group CC (normal diet) and TC (normal diet supplemented with 5 mg/kg thiram). The results revealed that low doses of thiram had a detrimental effect on broiler's growth performance, resulting in an approximate reduction of 669.33 g in their final body weight at day 45. Our findings indicated that low-dose thiram had a negative impact on the gut bacterial composition, leading to a notable reduction in the abundance of Merdibacter, Paenibacillus, Macrococcus, Fournierella, and Anaeroplasma (p < 0.05) compared to the CC group. Conversely, the relative level of Myroides was significantly increased (p < 0.05) in response to thiram exposure. In gut fungi, thiram significantly enhanced the diversity and richness of gut fungal populations (p < 0.05), as evidenced by the notable increase in alpha indices, i.e. ACE (CC: 346.49 ± 117.27 vs TC: 787.27 ± 379.14, p < 0.05), Chao 1 (CC: 317.63 ± 69.13 vs TC: 504.85 ± 104.50, p < 0.05), Shannon (CC: 1.28 ± 1.19 vs TC: 5.39 ± 2.66, p < 0.05), Simpson (CC: 0.21 ± 0.21 vs TC: 0.78 ± 0.34, p < 0.05). Furthermore, the abundance of Ascomycota, Kickxellomycota, and Glomeromycota were significantly increased (p < 0.05) by exposure to thiram, conversely, the level of Basidiomycota was decreased (p < 0.05) in the TC group compared to the CC group. Overall, this study demonstrated that low doses of thiram induced significant changes in the composition and abundance of gut microbiota in broilers, with more pronounced changes observed in the gut fungal community as compared to the gut bacterial community. Importantly, our findings further emphasize the potential risks associated with low dose thiram exposure and have revealed a novel discovery indicating that significant alterations in gut fungi may serve as the crucial factor contributing to the detrimental effects exerted by thiram residues.

Pilot-scale production of soybean oligopeptides and antioxidant and antihypertensive effects in vitro and in vivo.

Soybean oligopeptides (SOP) with low molecular weights were prepared by two-step enzymatic hydrolysis on a pilot-scale. Peptide and free amino acid contents of SOP were 82.5 ± 1.13 % and 3.7 ± 0.28 % respectively. The molecular weight distribution of SOP was mainly bellow 1,000 Da (85.4 %), 56.7 % of which were 140-500 Da. SOP showed strong stability to proteolytic digestion by pepsin and trypsin. The antioxidant activities and in vitro and in vivo antihypertensive effects of SOP were evaluated. Results showed that SOP exhibited 1,1-diphenyl-2-picrylhydrazyl radical scavenging effect (IC50 = 4.5 ± 0.13 mg/mL), and significantly inhibited lipid peroxidation in linoleic acid oxidation system (IC50 = 1.2 ± 0.09 mg/mL). SOP had potent angiotensin I-converting enzyme inhibitory activity (IC50 = 1.1 ± 0.06 mg/mL), and antihypertensive effect in spontaneously hypertensive rats at a dose of 200 mg/kg. This study indicated that SOP could be a natural antioxidative or antihypertensive compound in the medicine and food industries.

Isolation and identification of antioxidative peptides from pilot-scale black-bone silky fowl (Gallus gallus domesticus Brisson) muscle oligopeptides.

BACKGROUND: A pilot-scale production was developed to produce oligopeptide powder from black-bone silky fowl (Gallus gallus domesticus Brisson) muscle (BSFP) by two-step enzymatic hydrolysis and multistage separation. The resultant BSFP was assessed for antioxidant activities against four free radicals (hydroxyl, 1,1-dipheny-2-picrylhydrazyl (DPPH), superoxide and peroxyl) and against the peroxidation of linoleic acid in a lipid peroxidation model system. After separation by reversed-phase high-performance liquid chromatography (RP-HPLC), five major fractions of BSFP were tested for DPPH radical scavenging activity and subjected to mass spectrometry to identify the active peptides. RESULTS: BSFP showed potential antioxidant activity in four assay systems. Three RP-HPLC fractions produced higher antioxidant effect than BSFP, with Fraction 4 showing the strongest activity. A total of 18 peptides were identified, and two peptides - Leu-Trp-Arg and Asn-Met - had strong scavenging activity, with IC50 values of 2.28 ± 0.05 and 4.65 ± 0.09 mg mL(-1) , respectively. Asn-Met is a novel antioxidative peptide that has not been previously reported. CONCLUSIONS: The results showed that the pilot-scale production of BSFP was a practical way to produce peptides with high value and potential antioxidant activity. BSFP and its antioxidative peptides can be a source of natural antioxidant and used as a food additive.

Pharmacokinetics and tissue residues of hydrochloric acid albendazole sulfoxide and its metabolites in crucian carp (Carassius auratus) after oral administration.

The pharmacokinetics and residues elimination of hydrochloric acid albendazole sulfoxide (ABZSO) and its metabolites were studied in healthy crucian carp (Carassius auratus, 250 ± 30 g) kept at water temperatures of 10 °C and 25 °C. The concentrations of ABZSO and its metabolites concentration in plasma and tissues were determined using high-performance liquid chromatography (HPLC) using an ultraviolet detector. The results revealed that the plasma concentration of ABZSO in plasma was significantly higher than that of albendazole sulfone (ABZSO(2)), whereas albendazole-2-aminosulfone (ABZ-SO(2)NH(2)) was not detected. The plasma concentrations of ABZSO and its main metabolite ABZSO(2) concentration-time data were fitted using a single-compartment model at 10 °C and 25 °C. The absorption half-life (t1/2ka) of ABZSO was 3.86 h at 10 °C and 1.29 h at 25 °C, whereas the elimination half-life (t1/2ke) was 16.34 h at 10 °C and 6.72 h at 25 °C; the maximum plasma concentration (C(max)) and the time-point of maximum plasma concentration (T(p)) were calculated as 3.20 µg mL(-1) and 10.58 h at 10 °C, 4.39 µg mL(-1) and 3.80 h at 25 °C. The distribution volume (V(d)/F) of ABZSO was estimated to be 1.99 L kg(-1) at 10 °C and 1.53 L kg(-1) at 25 °C; the total body clearance (CL(b)) of ABZSO were computed as 0.08 and 0.19 L/(h kg) at 10 and 25 °C, respectively; the areas under the concentration-time curve (AUC) was 118.22 µg mL(-1)h at 10 °C and 63.12 µg mL(-1)h at 25 °C. The [Formula: see text] of ABZSO(2) was found to be 6.39 °C at 10 °C and 3.73 h at 25 °C, whereas the [Formula: see text] was 12.86 h at 10 °C and 6.56 h at 25 °C; the C(max) and T(p) of ABZSO(2) was calculated as 0.78 µg mL(-1) and 12.82 h at 10 °C, 1.03 µg mL(-1) and 7.04 h at 25 °C, respectively; the V(d)/F of ABZSO(2) were estimated to be 6.43 L kg(-1) at 10 °C and 4.61 Lkg(-1) at 25 °C; the CL(b) of ABZSO(2) were computed as 0.34 and 0.49 L/(h kg) at 10 °C and 25 °C, respectively; the AUC of ABZSO(2) were 28.86 µg mL(-1)h at 10 °C and 20.52 µg mL(-1)h at 25 °C. It was demonstrated that ABZSO(2) was the main metabolite of ABZSO. The concentrations of ABZSO and its main metabolite (ABZSO(2)) were detected in muscle, skin, liver and kidney, whereas ABZ-SO(2)NH(2) was only detected in liver and kidney. The ABZSO and it metabolite (ABZSO(2)) could still be detected at 4 d time-point after administration at both temperatures in all tissues. The results revealed that the depletion of ABZSO and its metabolite (ABZSO(2)) in crucian carp was slower with a long half-life time, especially at lower water temperature.

Preparation and evaluation of danofloxacin mesylate microspheres and its pharmacokinetics in pigs.

Danofloxacin mesylate gelatin microspheres (DFM-GMS) were prepared by an emulsion chemical crosslinking technique. Distribution of particle size, morphologic characteristics, drug content, and drug stability were evaluated. In-vitro study showed that the release of danofloxacin mesylate (DFM) from microspheres was much slower than from the raw material (DFM) in the release medium. Pharmacokinetic characteristics were evaluated following intramuscular injection of DFM-GMS or DFM in pigs at dosage of 2.5 mg/kg body weight. Elimination half-life (t(1/2ß)) of the drug was 24.32 h for DFM-GMS, and 6.61 h for DFM (P < 0.01). Overall, DFM-GMS could be applied as a long-acting and lung targeting dosage form of DFM for clinical application.