Effect of immunological enhancement of aloe polysaccharide on chickens immunized with Bordetella avium inactivated vaccine

Investigation and Identification of Fungal Diseases of Aloe barbadensis in China

The Aloe barbadensis industry plays an important role in the economic development of Yuanjiang county of Yuxi city in Yunnan province, China. In order to reduce the harm of diseases and ensure the quality of products, the occurrence of A. barbadensis was investigated. The pathogenic fungi of wild and cultivated species of A. barbadensis were isolated by a tissue separation method, and DNA sequencing was carried out by using the sequence analysis of the ribosomal rDNA-ITS region, and the pathogenic fungi were classified and identified by finally combining morphological observations. The results showed that the main fungal diseases were root rot and leaf rot disease caused by Fusarium oxysporum, leaf spot disease caused by Curvularia lunata, anthracnose caused by Colletotrichum boninense, and brown spot disease caused by Alternaria alternata on A. barbadensis.

Microbiome analysis reveals potential for modulation of gut microbiota through polysaccharide-based prebiotic feeding in Oreochromis niloticus (Linnaeus, 1758)

Characterization and functional profiling of the gut microbiota are essential for guiding nutritional interventions in fish and achieving favorable host-microbe interactions. Thus, we conducted a 30 days study to explore and document the gut microbial community of O. niloticus, as well as to evaluate the effects of a polysaccharide-based prebiotics with 0.5% and 0.75% Aloe vera extract on the gut microbiome through genomic analysis. The V3-V4 region of 16S rRNA was amplified and sequenced using Illumina HiSeq 2500, resulting in 1,000,199 reads for operational taxonomic unit (OTU) identification. Out of 8,894 OTUs, 1,181 were selected for further analysis. Our results revealed that Planctomycetes, Firmicutes, Proteobacteria, Verrucomicrobia, Actinobacteria, and Fusobacteria were the dominant phyla in both control and treatment samples. Higher doses of prebiotics were found to improve Planctomycetes and Firmicutes while decreasing Proteobacteria and Verrucomicrobia. We observed increasing trends in the abundance of Bacilli, Bacillaceae, and Bacillus bacteria at the class, family, and genus levels, respectively, in a dose-dependent manner. These findings were consistent with the conventional colony count data, which showed a higher prevalence of Bacillus in prebiotic-supplemented groups. Moreover, predicted functional analysis using PICRUSt indicated a dose-dependent upregulation in glycolysis V, superpathway of glycol metabolism and degradation, glucose and xylose degradation, glycolysis II, and sulfoglycolysis pathways. Most of the energy, protein, and amino acid synthesis pathways were upregulated only at lower doses of prebiotic treatment. Our findings suggest that the gut microbiome of O. niloticus can be optimized through nutritional interventions with plant-based polysaccharides for improved growth performance in commercial fish.

Structural characteristics and immune-enhancing activity of an extracellular polysaccharide produced by marine Halomonas sp. 2E1

Microbial polysaccharides from extreme environments, such as cold seeps and hydrothermal vents, usually exhibit novel structural features and diverse biological activities. In this study, an exopolysaccharide (EPS2E1) was isolated from cold-seep bacterium Halomonas sp. 2E1 and its immune-enhancing activity was evaluated. The total sugar content and protein content were determined as 83.1% and 7.9%, respectively. EPS2E1 contained mannose and glucose with the molar ratio of 3.76: 1. The molecular weight was determined to be 47.0 kDa. Structural analysis indicated that EPS2E1 was highly branched, the backbone mainly consisted of →2)-Man-(α-1→ and →2, 6)-Man-(α-1→ with the ratio of 2.45: 1.00. The chain also contained →4)-Glc-(α-1→, →6)-Man-(α-1→ and →3)-Glc-(β-1→. EPS2E1 could significantly increase the production of NO, COX-2, TNF-α, IL-1β and IL-6 by activating the MAPK and NF-κB pathways on RAW264.7 macrophages. EPS2E1 exhibits the potential to be an immunopotentiator in the near future.

Aloe Polysaccharides Inhibit Influenza A Virus Infection-A Promising Natural Anti-flu Drug

Influenza A virus causes periodic outbreaks and seriously threatens human health. The drug-resistant mutants have shown an epidemic trend because of the abuse of chemical drugs. Aloe polysaccharides (APS) extracted from Aloe vera leaves have evident effects on the therapy of virus infection. However, the activity of APS in anti-influenza virus has yet to be investigated. Here, we refined polysaccharides from A. vera leaf. In vitro test revealed that APS could inhibit the replication of a H1N1 subtype influenza virus, and the most obvious inhibitory effect was observed in the viral adsorption period. Transmission electron microscopy indicated that APS directly interacted with influenza virus particles. Experiments on PR8 (H1N1) virus infection in mice demonstrated that APS considerably ameliorated the clinical symptoms and the lung damage of the infected mice, and significantly reduced the virus loads and mortality. Our findings provided a theoretical basis for the development of novel natural anti-influenza agents.

Immuno-enhancement of Taishan Pinus massoniana pollen polysaccharides on recombinant Bordetella avium ompA expressed in Pichia pastoris

Bordetellosis, caused by Bordetella avium, continues to be an economic problem in the poultry industry of China. Vaccines with good protective ability are lacking. Thus, developing a novel vaccine against the B. avium infection is crucial. Here, we constructed a recombinant Pichia pastoris transformant capable of expressing the outer membrane protein A (ompA) of B. avium to prepare the recombinant ompA subunit vaccine and then evaluated its immune effects. To further investigate the immunomodulation effects of Taishan Pinus massoniana pollen polysaccharides (TPPPS) on this subunit vaccine, three concentrations (20, 40, and 60 mg/mL) of TPPPS were used as the adjuvants of the ompA subunit vaccine respectively. The conventional Freund's incomplete adjuvant served as the control of TPPPS. Chickens in different groups were separately vaccinated with these vaccines thrice. During the monitoring period, serum antibody titers, concentrations of serum IL-4, percentages of CD4(+) and CD8(+) T-lymphocytes in the peripheral blood, lymphocyte transformation rate, and protection rate were detected. Results showed that the pure ompA vaccine induced the production of anti-ompA antibody, the secretion of IL-4, the increase of CD4(+) T-lymphocytes counts and lymphocyte transformation rate in the peripheral blood. Moreover, the pure ompA vaccine provided a protection rate of 71.67% after the B. avium challenge. Notably, TPPPS adjuvant vaccines induced higher levels of immune responses than the pure ompA vaccine, and 60 mg/mL TPPPS adjuvant vaccine showed optimal immune effects and had a 91.67% protection rate. Our findings indicated that this recombinant B. avium ompA subunit vaccine combined with TPPPS had high immunostimulatory potential. Results provided a new perspective for B. avium subunit vaccine research.

The no-observed-adverse-effect level (NOAEL) of baby aloe powder (BAP) for nutraceutical application based upon toxicological evaluation

Aloe has been used in versatile herbal medications and nutraceuticals throughout history. Aloe is widely considered to be generally safe for humans and used globally. The effectiveness and pharmacological properties of aloe are dependent upon when the plant is collected. However, little is known about the toxicology of whole-body aloe collected within less than 1 yr. Based upon widespread exposure to aloe, it is important to determine a daily intake level of this chemical to ensure its safety for humans. To determine the no-observed-adverse-effect level (NOAEL) of baby aloe powder (BAP) for clinical application, Sprague-Dawley (SD) rats were treated orally for 4 wk with 4 different concentrations: 0, 0.125, 0.5, and 2 g/kg body weight (bw). In this study, no significant or dose-dependent toxicological effects of BAP were observed in biochemical or hematological parameters, urinalysis, clinical signs, body weight, and food and water consumption. There were changes in some biomarkers in certain treated groups compared to controls; however, all values were within their reference ranges and not dose-dependent. Based on these results, the NOAEL of BAP was estimated to be greater than 2 g/kg bw in male and 2 g/kg bw in female SD rats. Collectively, these data suggest that BAP used in this study did not produce any marked subacute toxic effects up to a maximum concentration of 2 g/kg bw, and thus use in nutraceuticals and in pharmaceutical and cosmetic applications at a concentration of >2 g/kg is warranted.

Effects of Taishan Pinus massoniana pollen polysaccharide on the subunit vaccine of Proteus mirabilis in birds

Three adjuvants, namely, Taishan Pinus massoniana pollen polysaccharide (TPPPS), white mineral oil (WO) and propolis (PP), were added to the outer membrane protein (OMP) of Proteus mirabilis (P. mirabilis) and their effects were compared. Three hundred 1-day-old chicks were randomly divided into five groups (I-V), with 60 chicks per group, and injected subcutaneously with WO-OMP vaccine (I), PP-OMP vaccine (II), TPPPS-OMP vaccine (III), OMP-only vaccine (IV) and physiological saline (V) at 3, 7 and 12 days old. On days 3, 7, 14, 21, 28, 35, 42 and 49 after the first vaccination, the antibody titers, interleukin-2 levels (IL-2) and T-lymphocyte proliferation rates in the peripheral blood as well as the secreting-type IgA levels (SIgA) in the duodenum were measured. On day 7 after the third vaccination, the chicks were challenged with P. mirabilis strain Q1 and the protective effects of each group were observed. The highest protective rate was observed in group III. Moreover, the antibody titers as well as IL-2, SIgA and T-lymphocyte proliferation rates in this group significantly increased and were significantly higher than those in the other groups at most time points. The results indicate that TPPPS could significantly enhance the effects of the subunit vaccine of P. mirabilis; induced stronger humoral, cellular and mucosal immunity as compared with WO and PP; and should be developed as a vaccine adjuvant.

The use of propolis as vaccine's adjuvant

The success of many vaccines relies on their association with selected adjuvants in order to increase their immunogenicity and ensure long-term protection. All available adjuvants have adverse effects due to their toxicity and reactogenicity. Pre-clinical in vivo investigations can identify new natural products for further applications. Several studies have confirmed the different medicinal benefits of propolis. However the studies that addressed its use as a potent, safe, vaccine adjuvant were limited to specific countries and languages, primarily Chinese. Those studies introduced the use of different extracts and formulations of propolis as adjuvants for bacterial, viral, and parasitic vaccines. This comprehensive up-to-date review categorizes, documents, and discusses those trials in a clear chronological manner.