Nicotinate-curcumin improves NASH by inhibiting the AKR1B10/ACCα-mediated triglyceride synthesis.

BACKGROUND: Nonalcoholic steatohepatitis (NASH) is a prevalent chronic liver condition. However, the potential therapeutic benefits and underlying mechanism of nicotinate-curcumin (NC) in the treatment of NASH remain uncertain. METHODS: A rat model of NASH induced by a high-fat and high-fructose diet was treated with nicotinate-curcumin (NC, 20, 40 mg·kg- 1), curcumin (Cur, 40 mg·kg- 1) and metformin (Met, 50 mg·kg- 1) for a duration of 4 weeks. The interaction between NASH, Cur and Aldo-Keto reductase family 1 member B10 (AKR1B10) was filter and analyzed using network pharmacology. The interaction of Cur, NC and AKR1B10 was analyzed using molecular docking techniques, and the binding energy of Cur and NC with AKR1B10 was compared. HepG2 cells were induced by Ox-LDL (25 µg·ml- 1, 24 h) in high glucose medium. NC (20µM, 40µM), Cur (40µM) Met (150µM) and epalrestat (Epa, 75µM) were administered individually. The activities of ALT, AST, ALP and the levels of LDL, HDL, TG, TC and FFA in serum were quantified using a chemiluminescence assay. Based on the changes in the above indicators, score according to NAS standards. The activities of Acetyl-CoA and Malonyl-CoA were measured using an ELISA assay. And the expression and cellular localization of AKR1B10 and Acetyl-CoA carboxylase (ACCα) in HepG2 cells were detected by Western blotting and immunofluorescence. RESULTS: The results of the animal experiments demonstrated that NASH rat model induced by a high-fat and high-fructose diet exhibited pronounced dysfunction in liver function and lipid metabolism. Additionally, there was a significant increase in serum levels of FFA and TG, as well as elevated expression of AKR1B10 and ACCα, and heightened activity of Acetyl-CoA and Malonyl-CoA in liver tissue. The administration of NC showed to enhance liver function in rats with NASH, leading to reductions in ALT, AST and ALP levels, and decrease in blood lipid and significant inhibition of FFA and TG synthesis in the liver. Network pharmacological analysis identified AKR1B10 and ACCα as potential targets for NASH treatment. Molecular docking studies revealed that both Cur and NC are capable of binding to AKR1B10, with NC exhibiting a stronger binding energy to AKR1B10. Western blot analysis demonstrated an upregulation in the expression of AKR1B10 and ACCα in the liver tissue of NASH rats, accompanied by elevated Acetyl-CoA and Malonyl-CoA activity, and increased levels of FFA and TG. The results of the HepG2 cell experiments induced by Ox-LDL suggest that NC significantly inhibited the expression and co-localization of AKR1B10 and ACCα, while also reduced levels of TC and LDL-C and increased level of HDL-C. These effects are accompanied by a decrease in the activities of ACCα and Malonyl-CoA, and levels of FFA and TG. Furthermore, the impact of NC appears to be more pronounced compared to Cur. CONCLUSION: NC could effectively treat NASH and improve liver function and lipid metabolism disorder. The mechanism of NC is related to the inhibition of AKR1B10/ACCα pathway and FFA/TG synthesis of liver.

A duplex nested RT-PCR method for monitoring porcine epidemic diarrhea virus and porcine delta-coronavirus.

BACKGROUND: Porcine epidemic diarrhea virus (PEDV) and porcine delta-coronavirus (PDCoV) are economically important pathogens that cause diarrhea in sows and acute death of newborn piglets. Moreover, the emerging PDCoV was reported to infect children. The current situation is that vaccine prevention has not met expectations, and emergency containment strategies following outbreaks cannot prevent the damages and losses already incurred. Therefore, a more sensitive detection method, that is both convenient and enables accurate and effective sequencing, that will provide early warning of PEDV and PDCoV is necessary. This will enable active, effective, and comprehensive prevention and control, which will possibly reduce disease occurrences. RESULTS: Duplex nested RT-PCR (dnRT-PCR) is an ideal method to achieve early warning and monitoring of PEDV and PDCoV diseases, and to additionally investigate any molecular epidemiological characteristics. In this study, two pairs of primers were designed for each virus based upon the highly conserved N protein sequences of both PEDV and PDCoV strains retrieved from the NCBI Genbank. After optimization of the reaction conditions, the dnRT-PCR assay amplified a 749-bp fragment specific to PEDV and a 344-bp fragment specific to PDCoV. Meanwhile, the specificity and sensitivity of the primers and clinical samples were tested to verify and establish this dnRT-PCR method. The limit of detection (LoD)for both PEDV and PDCoV was 10 copies/µL. The results showed that among 251 samples, 1 sample contained PEDV infection, 19 samples contained a PDCoV infection, and 8 samples were infected with both viruses, following the use of dnRT-PCR. Subsequently, the positive samples were sent for sequencing, and the sequencing results confirmed that they were all positive for the viruses detected using dnRT-PCR, and conventional RT-PCR detection was conducted again after the onset of disease. As these results were consistent with previous results, a detection method for PEDV and PDCoV using dnRT-PCR was successfully established. In conclusion, the dnRT-PCR method established in this study was able to detect both PEDV and PDCoV, concomitantly. CONCLUSIONS: The duplex nested RT-PCR method represents a convenient, reliable, specific, sensitive and anti-interference technique for detecting PEDV and PDCoV, and can additionally be used to simultaneously determine the molecular epidemiological background.

Safety assessment of MPTA: An oral acute and 90-day sub-chronic toxicity study in Sprague-Dawley rats.

MPTA is a novel extract product derived from Macleaya cordata (Willd.) R. Br., which has good anti-inflammatory and antioxidant activity. The aim of this study was to investigate the acute oral toxicity and 90-day sub-chronic oral toxicity of MPTA. In the acute toxicity study, 50 SD rats of both sexes were randomly divided into 5 groups and dosed in a gradient from 197.53 mg/kg to 1000.00 mg/kg bw. Toxic effects were observed up to 14 days and LD50 was calculated. In a subchronic toxicity test, male and female SD rats were orally dosed repeatedly with 96.40, 19.28, 3.86 mg/kg bw of MPTA for 90 days. In addition, a control group was set up in the subchronic study. The acute toxicity test showed that the oral LD50 of MPTA was 481.99 mg/kg with a 95% confidence interval of 404.24-574.70 mg/kg. MPTA did not appear to induce toxic effects in the longer term in terms of food and water consumption, weight gain, haematological and clinical biochemical parameters and pathological examination. The first data on the potential toxicity of MPTA was provided to highlight the safety of short-term to longer-term oral administration of MPTA, and the experimental results yield and establish a NOEAL of 96.40 mg/kg/d for MPTA.

Cryptochrome 2 from Lilium × formolongi Regulates Photoperiodic Flowering in Transgenic Arabidopsis thaliana.

The photoperiodic flowering pathway is essential for plant reproduction. As blue and ultraviolet-A light receptors, cryptochromes play an important role in the photoperiodic regulation of flowering. Lilium × formolongi is an important cut flower that flowers within a year after seed propagation. Floral induction is highly sensitive to photoperiod. In this study, we isolated the CRYPTOCHROME2 gene (LfCRY2) from L. × formolongi. The predicted LfCRY2 protein was highly homologous to other CRY2 proteins. The transcription of LfCRY2 was induced by blue light. LfCRY2 exhibits its highest diurnal expression during the floral induction stage under both long-day and short-day photoperiods. Overexpression of LfCRY2 in Arabidopsis thaliana promoted flowering under long days but not short days, and inhibited hypocotyl elongation under blue light. Furthermore, LfCRY2 was located in the nucleus and could interact with L. × formolongi CONSTANS-like 9 (LfCOL9) and A. thaliana CRY-interacting basic-helix-loop-helix 1 (AtCIB1) in both yeast and onion cells, which supports the hypothesis that LfCRY2 hastens the floral transition via the CIB1-CO pathway in a manner similar to AtCRY2. These results provide evidence that LfCRY2 plays a vital role in promoting flowering under long days in L. × formolongi.

Systematic identification of compounds in Macleaya microcarpa by high-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry combined with mass spectral fragmentation behavior of Macleaya alkaloids.

RATIONALE: Macleaya microcarpa (Maxim.) Fedde belongs to the genus Macleaya of the Papaveraceae family. Benzylisoquinoline alkaloids (BIAs) are considered the main bioactive constituents of M. microcarpa. METHODS: Using high-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (HPLC/QTOFMS/MS) we identified BIAs in the aerial parts of M. microcarpa in the early flowering stage. Target profiling and identification of BIAs in the extracted samples from the fresh aerial parts of M. microcarpa were exclusively based on a personal, accurate, mass database of known compounds and the mass spectral fragmentation behavior of Macleaya alkaloids. RESULTS: A total of 97 alkaloids, comprising 7 benzyltetrahydroisoquinolines, 1aporphine, 9 tetraprotoberberines, 3 protoberberines, 2 N-methyltetrahydroprotoberberines, 4 protopines, 47 dihydrobenzophenanthridines, and 24 benzophenanthridines, were identified from the fresh aerial parts of M. microcarpa, and 77 of these were detected for the first time in M. microcarpa. In addition, some of the screened alkaloids were related to the biosynthetic pathways of sanguinarine and chelerythrine. CONCLUSIONS: The integrated method is sensitive and reliable for screening and identifying trace or ultra-trace isoquinoline alkaloids and has contributed to a better understanding of BIAs in the fresh aerial parts of M. microcarpa.

Pharmacokinetics of sanguinarine, chelerythrine, and their metabolites in broiler chickens following oral and intravenous administration.

Sanguinarine (SA) and chelerythrine (CHE) are the main active components of the phytogenic livestock feed additive, Sangrovit®. However, little information is available on the pharmacokinetics of Sangrovit® in poultry. The goal of this work was to study the pharmacokinetics of SA, CHE, and their metabolites, dihydrosanguinarine (DHSA) and dihydrochelerythrine (DHCHE), in 10 healthy female broiler chickens following oral (p.o.) administration of Sangrovit® and intravenous (i.v.) administration of a mixture of SA and CHE. The plasma samples were processed using two different simple protein precipitation methods because the parent drugs and metabolites are stable under different pH conditions. The absorption and metabolism of SA following p.o. administration were fast, with half-life (t1/2 ) values of 1.05 ± 0.18 hr and 0.83 ± 0.10 hr for SA and DHSA, respectively. The maximum concentration (Cmax ) of DHSA (2.49 ± 1.4 µg/L) was higher that of SA (1.89 ± 0.8 µg/L). The area under the concentration vs. time curve (AUC) values for SA and DHSA were 9.92 ± 5.4 and 6.08 ± 3.49 ng/ml hr, respectively. Following i.v. administration, the clearance (CL) of SA was 6.79 ± 0.63 (L·h-1 ·kg-1 ) with a t1/2 of 0.34 ± 0.13 hr. The AUC values for DHSA and DHCHE were 7.48 ± 1.05 and 0.52 ± 0.09 (ng/ml hr), respectively. These data suggested that Sangrovit® had low absorption and bioavailability in broiler chickens. The work reported here provides useful information on the pharmacokinetic behavior of Sangrovit® after p.o. and i.v. administration in broiler chickens, which is important for the evaluation of its use in poultry.

Characterization of in vitro metabolites of three tetrahydroprotoberberine alkaloids in rat liver S9 by high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

RATIONALE: Tetrahydroberberine (THB), tetrahydrocoptisine (THCP) and tetrahydrocolumbamine (THCB) belong to the tetrahydroprotoberberine (THPB) alkaloids. Most of them have been extensively studied because of their pharmacological activities such as anti-hypertension, anti-arrhythmia, antimicrobial activity and antioxidant. However, limited information on the pharmacokinetics and metabolism of the three alkaloids has been reported. The purpose of this study was to investigate the in vitro metabolism of THB, THCP and THCB in rat liver S9 by using a rapid and accurate high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC/QqTOF-MS) method. METHODS: The incubation mixture was processed with 15% trichloroacetic acid. Chromatographic separation of the three THPB alkaloids and their metabolites was achieved by HPLC/QqTOF-MS and accurate mass measurements of metabolites were automatically performed through data-dependent acquisition in only a 30-min analysis. The detailed structural elucidations of these metabolites were performed by comparing the changes in their accurate molecular masses, elemental compositions and product ions with those of the parent drug. RESULTS: Five, five and four metabolites of THB, THCP and THCB were identified in rat liver S9, respectively. The results show that O-demethylenation of the 9,10-vicinal methoxyl group was the main metabolic pathway of THB and THCB and that demethylenation of the two methylenedioxy groups was the main metabolic pathway of THCP. In addition, minor oxidation and methylation reactions could occur for these alkaloids in rat liver S9. CONCLUSIONS: This was the first investigation of the in vitro metabolism of THB, THCP and THCB in rat liver S9 by using a sensitive and accurate HPLC/QqTOF-MS method. The tentatively proposed metabolic pathways of the three alkaloids will provide a basis for further studies of the in vivo metabolism of the three compounds in animals and humans.

Medicinal plants of the genus Macleaya (Macleaya cordata, Macleaya microcarpa): A review of their phytochemistry, pharmacology, and toxicology.

In the genus Macleaya, Macleaya cordata and Macleaya microcarpa have been recognized as traditional herbs that are primarily distributed in China, North America, and Europe and have a long history of medicinal usage. These herbs have been long valued and studied for detumescence, detoxification, and insecticidal effect. This review aims to provide comprehensive information on botanical, phytochemical, pharmacological, and toxicological studies on plants in the genus Macleaya. Plants from the genus of Macleaya provide a source of bioactive compounds, primarily alkaloids, with remarkable diversity and complex architectures, thereby having attracted attention from researchers. To date, 291 constituents have been identified and/or isolated from this group. These purified compounds and/or crude extract possess antitumor, anti-inflammatory, insecticidal, and antibacterial activities in addition to certain potential toxicities. Macleaya species hold potential for medicinal applications. However, despite the pharmacological studies on these plants, the mechanisms underlying the biological activities of active ingredients derived from Macleaya have not been thoroughly elucidated to date. Additionally, there is a need for research focusing on in vivo medical effects of Macleaya compounds and, eventually, for clinical trials.

[Research strategies for feed additives and veterinary medicines from side products of Chinese medicine resources industrialization].

The global antimicrobial resistance has been a big challenge to the human health for years. It has to make balance between the safety of animal products and the use of antimicrobials in animal husbandry. Any methods that can minimize or even phase out the use of antimicrobials in animal husbandry should be encouraged. We herein describe the research strategies for feed additives and veterinary medicines from the side products of Chinese medicine resources industrialization. Killing two birds with one stone-besides the major purposes, the rational utilization of non-medicinal parts and wastes of industrialization of Chinese herbal medicines is also achieved under the proposed strategies.

Identification of allocryptopine and protopine metabolites in rat liver S9 by high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry.

RATIONALE: Allocryptopine (AL) and protopine (PR) have been extensively studied because of their anti-parasitic, anti-arrhythmic, anti-thrombotic, anti-inflammatory and anti-bacterial activity. However, limited information on the pharmacokinetics and metabolism of AL and PR has been reported. Therefore, the purpose of the present study was to investigate the in vitro metabolism of AL and PR in rat liver S9 using a rapid and accurate high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (HPLC/QqTOFMS) method. METHODS: The incubation mixture was processed with 15% trichloroacetic acid (TCA). Multiple scans of AL and PR metabolites and accurate mass measurements were automatically performed simultaneously through data-dependent acquisition in only a 30-min analysis. The structural elucidations of these metabolites were performed by comparing their changes in accurate molecular masses and product ions with those of the precursor ion or metabolite. RESULTS: Eight and five metabolites of AL and PR were identified in rat liver S9, respectively. Among these metabolites, seven and two metabolites of AL and PR were identified in the first time, respectively. The demethylenation of the 2,3-methylenedioxy, the demethylation of the 9,10-vicinal methoxyl group and the 2,3-methylenedioxy group were the main metabolic pathways of AL and PR in liver S9, respectively. In addition, the cleavage of the methylenedioxy group of the drugs and subsequent methylation or O-demethylation were also the common metabolic pathways of drugs in liver S9. In addition, the hydroxylation reaction was also the metabolic pathway of AL. CONCLUSIONS: This was the first investigation of in vitro metabolism of AL and PR in rat liver S9. The detailed structural elucidations of AL and PR metabolites were performed using a rapid and accurate HPLC/QqTOFMS method. The metabolic pathways of AL and PR in rat were tentatively proposed based on these characterized metabolites and early reports. Copyright © 2016 John Wiley & Sons, Ltd.

[A new 6,6a-offbenzophenanthridine alkaloid from Macleaya cordata].

A new alkaloid was isolated from the leaves of Macleaya cordata with 95% ethanol extracted and its isolation was by column chromatography and preparation HPLC. The new structure was elucidated as 6'-hydroxy-2',3'-dimethoxyarnottianamide on the basis of its spectroscopic date.

[Study on Alkaloids of Fruit from Macleaya cordata].

Objective: To study the alkaloids from the fruit of Macleaya cordata. Methods: The alkaloids were isolated and purified by silica gel column chromatography and preparative high performance liquid chromatography,and the structures were elucidated based on the spectral data. Results: Eight alkaloids were obtained from the fraction of ethanol extract and identified as 6-cyanodihydrosanguinarine( 1),6-acetonyldihydrosanguinarine( 2),6-acetonyldihydrochelerythrine( 3),chelerythrine( 4),dihydrochelerythrine( 5),13,14-dehydrogen-N-methyl-coptisine( 6),N-methyl-canadine( 7) and berberine( 8). Conclusion: Compounds 1 and 6 are new nature products,and compound 7 is isolated from this plant for the first time.

[Chemical Constituents from the Roots of Macleaya cordata].

Objective: To investigate the chemical constituents from the roots of Macleaya cordata. Methods: The compounds were isolated and purified by silica gel,recrystallization and semi-preparative HPLC, their structures were eclucidated by physicochemistry properties, MS and NMR. Results: Seven compounds were isolated and identified as 6-cyanodihydrochelerythrine (1),6-cyanodihydrochelilutine (2),dihydrochelirubine (3),6-methoxynorchelerythrine (4),dihydrosanguinarine (5),6-actonyldihydrosanguinarine (6) and stigmasterol (7). Conclusion: Compounds 1,2 are new natural compounds and compound 4 is obtained from Macleaya cordata for the first time.

Ascorbic Acid-Initiated Tandem Radical Cyclization of N-Arylacrylamides to Give 3,3-Disubstituted Oxindoles.

An ascorbic acid-promoted and metal-free tandem room temperature cyclization of N-arylacrylamides with 4-nitrobenzenediazonium generated in situ was developed. This reaction proceeds smoothly through a radical mechanism and provides an environmentally friendly alternative approach to biologically active 3-alkyl-3-benzyloxindoles, avoiding the use of excess oxidants and light irradiation.

Structural speculation and identification of alkaloids in Macleaya cordata fruits by high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry combined with a screening procedure.

RATIONALE: Alkaloids with significant therapeutic effects are the main active constituents of Macleaya cordata, which is a perennial herb plant in the Papaveraceae family. A systematic and novel method for speculating and identifying the structures of alkaloids in M. cordata fruits by high-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (HPLC/Q-TOF-MS) with a screening procedure was reported. METHODS: Investigation of mass spectral fragmentation of alkaloids was carried out based on the tandem mass spectrometry (MS/MS) data analyses of eight reference substances. The skeletons of alkaloids were determined by their ultraviolet spectra (UV) and MS/MS data. The substituent groups of the alkaloids were acquired through a screening procedure developed in our laboratory and MS/MS data. The substituent linkage sites were deduced by MS/MS fragmentation behavior, as well as biosynthetic pathways of related alkaloids. RESULTS: The structures of 21 alkaloids were speculated in this study, 10 of which were reported for the first time in M. cordata. Furthermore, benzyltetrahydroisoquinoline and N-methyltetrahydroprotoberberine-type alkaloids were discovered, which indirectly proved that the biosynthetic pathways of benzophenanthridine alkaloids reported in Eschscholtzia california existed in M. cordata as well. CONCLUSIONS: HPLC/Q-TOF-MS combined with a screening procedure was a systematic and reliable method for speculating and elucidating the structures of alkaloids. This study might be useful for the identification of other compounds in herbal medicines.

Exploring the Anti-inflammatory Effects of Protopine Total Alkaloids of Macleaya Cordata (Willd.) R. Br.

Macleaya cordata (Willd). R. Br. is a Chinese medicinal plant commonly used externally to treat inflammatory-related diseases such as arthritis, sores, and carbuncles. This study aimed to evaluate the anti-inflammatory activity of protopine total alkaloids (MPTAs) in Macleaya cordata (Willd.) R. Br. in vivo tests in rats with acute inflammation showed that MPTA (2.54 and 5.08 mg/kg) showed significant anti-inflammatory activity 6 h after carrageenan injection. Similarly, MPTA (3.67 and 7.33 mg/kg) showed significant anti-inflammatory activity in the mouse ear swelling test. In addition, the potential mechanisms of the anti-inflammatory effects of MPTA were explored based on network pharmacology and molecular docking. The two main active components of MPTA, protopine and allocryptopine, were identified, and the potential targets and signaling pathways of MPTA's anti-inflammatory effects were initially revealed using tools and databases (such as SwissTargetPrediction, GeneCards, and STRING) combined with molecular docking results. This study provides the basis for the application of MPTA as an anti-inflammatory agent.

Acute, chronic, and genotoxic studies on the protopine total alkaloids of the Macleaya cordata (willd.) R. Br. in rodents.

The protopine alkaloids are widely distributed within the opium poppy family and have a wide range of pharmacological effects. MPTA is a product of the protopine total alkaloids extracted from the Macleaya cordata (Willd.) R. Br. Previously, we reported good anti-inflammatory activity of MPTA as well as oral acute and sub-chronic toxicity studies in rats. In order to perform a systematic toxicological safety assessment of MPTA, oral acute toxicity, genotoxicity (bone marrow cell chromosome aberration test, sperm abnormality test, bone marrow cell micronucleus test, and rat teratogenicity test), and chronic toxicity in mice were performed in this study. In the oral acute toxicity test, the LD50 in ICR mice was 481.99 mg/kg, with 95% confidence limits ranging from 404.27 to 574.70 mg/kg. All three mutagenicity tests tested negative in the range of 60.25-241.00 mg/kg. The results of the teratogenicity test in rats showed no reproductive or embryonic developmental toxicity at only 7.53 mg/kg, which can be considered as a no observed effect level (NOEL) for the teratogenicity test. Therefore, MPTA is safe for use at the doses tested, but attention should be paid to the potential risk to pregnant animals and the safety evaluation and toxicity mechanisms in target animals should be further investigated.

Preclinical safety evaluation of Macleaya Cordata extract: A re-assessment of general toxicity and genotoxicity properties in rodents.

Macleaya cordata extract (MCE) is widely used for its diverse pharmacological actions and beneficial effects on farm animals. Modern pharmacological studies have shown that it has anti-inflammatory, anti-cancer, and anti-bacterial activities, and is gradually becoming a long-term additive veterinary drug used to improve animal intestinal health and growth performance. Although some evidence points to the DNA mutagenic potential of sanguinarine (SAN), a major component of MCE, there is a lack of sufficient basic toxicological information on the oral route, posing a potential safety risk for human consumption of food of animal origin. In this study, we assessed the acute oral toxicity, repeated 90-day oral toxicity and 180-day chronic toxicity of MCE in rats and mice and re-evaluated the genotoxicity of MCE using a standard combined in vivo and ex vivo assay. In the oral acute toxicity test, the LD50 for MCE in rats and mice was 1,564.55 mg/kg (95% confidence interval 1,386.97-1,764.95 mg/kg) and 1,024.33 mg/kg (95% confidence interval 964.27-1,087.30 mg/kg), respectively. The dose range tested had no significant effect on hematology, clinical chemistry, and histopathological findings in rodents in the long-term toxicity assessment. The results of the bacterial reverse mutation, sperm abnormality and micronucleus test showed negative results and lack of mutagenicity and teratogenicity; the results of the rat teratogenicity test showed no significant reproductive or embryotoxicity. The results indicate that MCE was safe in the dose range tested in this preclinical safety assessment. This study provides data to support the further development of maximum residue limits (MRLs) for MCE.

Natural selenium stress influences the changes of antibiotic resistome in seleniferous forest soils.

BACKGROUND: Metal(loid)s can promote the spread and enrichment of antibiotic resistance genes (ARGs) in the environment through a co-selection effect. However, it remains unclear whether exposure of microorganisms to varying concentrations of selenium (Se), an essential but potentially deleterious metal(loid) to living organisms, can influence the migration and distribution of ARGs in forest soils. RESULTS: Precisely 235 ARGs conferring resistance to seven classes of antibiotics were detected along a Se gradient (0.06-20.65 mg kg-1) across 24 forest soils. (flor)/(chlor)/(am)phenicol resistance genes were the most abundant in all samples. The total abundance of ARGs first increased and then decreased with an elevated available Se content threshold of 0.034 mg kg-1 (P = 2E-05). A structural equation model revealed that the dominant mechanism through which Se indirectly influences the vertical migration of ARGs is by regulating the abundance of the bacterial community. In addition, the methylation of Se (mediated by tehB) and the repairing of DNA damages (mediated by ruvB and recG) were the dominant mechanisms involved in Se resistance in the forest soils. The co-occurrence network analysis revealed a significant correlated cluster between Se-resistance genes, MGEs and ARGs, suggesting the co-transfer potential. Lelliottia amnigena YTB01 isolated from the soil was able to tolerate 50 µg mL-1 ampicillin and 1000 mg kg-1 sodium selenite, and harbored both Se resistant genes and ARGs in the genome. CONCLUSIONS: Our study demonstrated that the spread and enrichment of ARGs are enhanced under moderate Se pressure but inhibited under severe Se pressure in the forest soil (threshold at 0.034 mg kg-1 available Se content). The data generated in this pilot study points to the potential health risk associated with Se contamination and its associated influence on ARGs distribution in soil.

Effect of Dietary Ramie Powder (Boehmeria nivea) at Various Levels on Growth Performance, Carcass and Meat Qualities, Biochemical Indices, and Antioxidative Capacity of Linwu Ducks.

Current experiment was designed to check the effect of dietary supplementation of ramie powder on the growth performance, carcass and meat qualities and antioxidative capacity of Linwu ducks. A total of 312 ducks at 21-day-age were equally divided into 4 groups, fed with control diet, control diet supplemented of 3, 6, or 12% ramie powder, respectively. The results showed that dietary supplementation of 6 and 12% ramie powder increased the final weight and daily body weight gain (P < 0.05), and dietary supplementation of 6% ramie improved the cooking loss of the leg meat 45-mins-postmortem compared with the control group (P < 0.05). Moreover, dietary supplementation of 6% ramie powder promoted the antioxidative capacity of the ducks by increasing the serum activities of superoxide dismutase and glutathione (P < 0.05), as well as the mRNA expressions of glutathione peroxidase 1 in the breast meat and superoxide dismutase 1 in the leg meat (P < 0.05). This experiment demonstrated that dietary supplementation of ramie powder showed beneficial efficacy on the growth performance of Linwu ducks. It corroborated the potential of dietary ramie being used as poultry feed ingredient and suggested that 6% was the proper supplementation rate of ramie powder in Linwu ducks' feed.