Adjuvant Effects of Platycodin D on Immune Responses to Infectious Bronchitis Vaccine in Chickens.

Adjuvants are common vaccine components. Novel adjuvants may improve the protective immunity conferred by vaccines against poultry diseases. Here, a less-hemolytic saponin, platycodin D (PD), isolated from the root of Platycodon grandiflorum was investigated as a potential alternative adjuvant. PD was tested as an adjuvant in the infectious bronchitis (IB) vaccine, because the existing IB vaccine has often failed to induce effective immune responses. The adjuvant activity of PD in conjunction with IB vaccine was evaluated in this study. Compared to control treatment, PD treatment significantly increased the proliferation of chicken peripheral blood mononuclear cells, concentration of interferon-γ in culture supernatants, and anti-IB antibody titer. In chickens pre-challenged with the Mass 41 infectious bronchitis virus (IBV), PD administration resulted in fewer and less severe clinical signs, lower mortality rate, and higher protection compared to control treatment. Histopathological examination showed that the lungs and kidneys of PD-treated chickens displayed fewer pathological lesions than those of control chickens. Our results also demonstrated that this new vaccine adjuvant improved chicken humoral and cellular immune responses without any side effects. Hence, our findings suggest that PD might serve as an effective adjuvant in IBV vaccines.

Effect of the flavonoid baicalein as a feed additive on the growth performance, immunity, and antioxidant capacity of broiler chickens.

Baicalein, the main flavonoid extracted from the root of Scutellaria baicalensis Georgi, has been demonstrated to exert multiple pharmacological effects, and thus could be utilized as a potential feed additive in broiler chickens. This study evaluated the effects of broiler chicken diet supplementation with baicalein on growth performance, immunity, and antioxidant activity at levels of 100 and 200 mg/kg. No significant effect on average daily feed intake (P > 0.05) of broilers with diets supplemented with baicalein was found compared to those on the basal diet or butylated hydroxytoluene (BHT) during the 35-d feeding trial. The addition of baicalein to the basal diet significantly increased average body weight, body weight gain, average weight gain, and the feed conversion ratio of birds during 21 to 42 d and 7 to 42 d of age, respectively. The best numerical values for the overall growth performance were observed in broilers fed on diets containing 200 mg/kg of baicalein. Baicalein supplementation significantly increased the ratio of CD3+/CD4+ and CD3±/CD8+, the concentration of IFN-γ, anti-IB antibody titer, and the spleen index compared with the control group (P < 0.05). Total cholesterol, the ratio of non-HDL-C/HDL-C, LDL-C/HDL-C, TC/HDL-C, triglycerides, and low-density lipoprotein cholesterol were significantly decreased after intake of baicalein compared with both the basal diet and the BHT-supplemented diet, whereas the SOD, GSH-Px, and CAT activity in the serum increased with the supplementation of baicalein. The T-AOC activity, T-SOD, and GSH-Px level in liver tissues was significantly increased by inclusion of baicalein, and intake of baicalein or BHT significantly decreased the malondialdehyde level found both in serum and meat tissue. Thus, the results obtained here indicate that the baicalein can be used as an effective natural feed additive in broiler chicken diets, and that 100 to 200 mg/kg can be considered as the optimum dosage.

[SNP marker and allele-specific diagnostic PCR for authenticating herbs of Perilla].

AIM: To authenticate all the varieties of Perilla (single-species genus), to analyze sequences of rDNA ITS regions and single nucleotide polymorphism (SNP) within them and based on these, to design allele-specific diagnostic PCR primers. METHODS: The rDNA ITS regions of the perilla varieties were sequenced and analyzed by Clustal X 1.8, MEGA 3.0. Allele-specific diagnostic PCR primers that can authenticate all the perilla varieties were designed based on SNPs loci. RESULTS: The length of rDNA ITS sequences of perilla varieties ranged from 612 to 615 bp in size, including ITS1 (230 -232 bp), 5.8S (179 bp) and ITS2 (203 -204 bp). The GC content is about 61.5% - 61.9%. There is not only SNPs in non-coding region ITS1 and ITS2 (ncSNP), but also three coding SNPs (cSNP) loci in the conservative region of 5.8S. All the SNPs have only two allele loci polymorphism. The cSNP in 5.8S is related to the morphology variation among the varieties. Allele-specific diagnostic PCR primers have been designed according to SNPs loci to authenticate accurately all the seeds and leaves of Perilla varieties. CONCLUSION: SNPs in rDNA ITS region can be used as an effective molecular markers to authenticate all the varieties of Perilla.