Effects of Chinese gallnut tannic acid on growth performance, blood parameters, antioxidative status, intestinal histomorphology, and cecal microbial shedding in broilers challenged with aflatoxin B1.

The objective of the present study was to investigate the effects of tannic acid (TA) on growth performance, blood parameters, antioxidant capacity, and intestinal health in broilers challenged with aflatoxin B1 (AFB1). A total of 480 broilers aged 1 d were randomly allotted into four treatments: 1) CON, control diet; 2) AF, CON + 60 µg/kg AFB1 of feed during days 1 to 21, CON + 120 µg/kg AFB1 of feed during days 22 to 42; 3) TA1, AF + 250 mg/kg TA; and 4) TA2, AF + 500 mg/kg TA. Average daily gain (ADG) and average daily feed intake (ADFI) were increased in the TA1 during days 1 to 21, days 22 to 42, and days 1 to 42 compared with CON and AF treatments (P < 0.05). Broilers fed the TA2 diet had greater ADG and ADFI than those fed the CON and AF diets during the finisher and the whole period (P < 0.05). Administration of TA decreased the relative weight of liver and kidney compared with broilers fed the AF diet on day 42 (P < 0.05). The blood activity of alanine transferase (ALT) and gamma-glutamyl transferase (GGT) was increased in the AF treatment compared with the CON (P < 0.05). Broilers fed the TA1 decreased the ALT content on day 21, and the level of ALT and GGT was decreased in the TA2 compared with the AF group on day 42 (P < 0.05). The activity of total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) in plasma, and the hepatic glutathione S-transferase (GST) was decreased in the AF group compared with the CON group (P < 0.05). The TA decreased plasma malondialdehyde concentration, and increased plasma T-SOD, GSH-Px, total antioxidant capacity, and hepatic GST activity compared with the AF (P < 0.05). The crypt depth of the jejunum was decreased in the TA1 treatment on day 21, and the villus height of the ileum was increased in the TA2 group on day 42 compared with the AF treatment (P < 0.05). The cecal Lactobacillus counts on day 21 were tended to increase in the TA treatments compared with the AF (P = 0.061). In conclusion, dietary inclusion of 250 and 500 mg/kg TA could improve the growth, antioxidant capacity, and partially protected the intestinal health of broilers challenged with AFB1.

Aflatoxin B1 (AFB1) is well known for its growth retardation, hepatotoxic, immunosuppressive, and other negative effects both in humans and poultry. Plant extracts such as tannic acid (TA) have been demonstrated as effective agents to control AFB1 contamination. The objective of this study was to evaluate the effects of Chinese gallnut TA in preventing aflatoxicosis in broilers. Broilers received one of four treatments: CON, control diet; AF, control diet with AFB1; TA1, AF + 250 mg/kg TA; TA2, AF + 500 mg/kg TA. Although AF did not decrease the growth performance of broilers, 250 and 500 mg/kg TA had greater average daily gain and average daily feed intake than those in the CON and AF. The relative weight of liver and kidney, blood alanine transferase, and gamma-glutamyl transferase activity were increased, and the antioxidant status was depressed in chicks fed the AF diet compared with the CON group. Dietary supplementation with 250 and 500 mg/kg TA ameliorated all the above-mentioned negative effects of AFB1. Moreover, the crypt depth of the jejunum was decreased, and the villus height of the ileum was increased in TA treatments compared with the AF. Conclusively, Chinese gallnut TA could be considered as a potential natural agent for the prevention of AFB1-induced oxidative and intestinal damage of broilers.

[Cloning and bioinformatic analysis and expression analysis of beta-glucuronidase in Scutellaria baicalensis].

The ß-Glucuronidase gene (sbGUS) cDNA firstly from Scutellari abaicalensis leaf was cloned by RT-PCR, with GenBank accession number KR364726. The full length cDNA of sbGUS was 1 584 bp with an open reading frame (ORF), encoding an unstable protein with 527 amino acids. The bioinformatic analysis showed that the sbGUS encoding protein had isoelectric point (pI) of 5.55 and a calculated molecular weight about 58.724 8 kDa, with a transmembrane regions and signal peptide, had conserved domains of glycoside hydrolase super family and unintegrated trans-glycosidase catalytic structure. In the secondary structure, the percentage of alpha helix, extended strand, ß-extended and random coil were 25.62%, 28.84%, 13.28% and 32.26%, respectively. The homologous analysis indicated the nucleotide sequence 98.93% similarity and the amino acid sequence 98.29% similarity with S. baicalensis (BAA97804.1), in the nine positions were different. The expression level of sGUS was the highest in root based on a real-time PCR analysis, followed by flower and stem, and the lowest was in stem. The results provide a foundation for exploring the molecular function of sbGUS involved in baicalcin biosynthesis based on synthetic biology approach in S. baicalensis plants.