Structural characteristics and wound-healing effects of Bletilla striata fresh tuber polysaccharide.

A homogeneous polysaccharide from Bletilla striata fresh tuber (BSPS) was prepared and extensively characterized using HP-GPC, colorimetry, FT-IR, methylation, GC-MS, NMR, Congo red experiment, SEM and AFM. The molecular weight of BSPS was 722.90 kDa. BSPS consisted of glucose and mannose in the molar ratio of 1: 2.5. BSPS had a linear chain structure consisting mainly of →4)-ß-d-Glcp-(1 → and →4)-ß-d-Manp-(1 → residues. O-acetyl group linked to C2 of →4)-ß-d-Manp-(1 → residue. Its monosaccharide molar ratio, molecular weight, and O-acetyl substituted position were different from that of the polysaccharide from B. striata dried tuber reported previously. Furthermore, BSPS significantly promoted the viability (ca. 10 % at concentrations of 3.125-25 µg/mL), differentiation (1.5-4 folds), migration (15 %-70 %), and invasion (1.84-4.65 folds) of C2C12 cells. Of note, BSPS remarkably accelerated the epidermal regeneration and wound healing in mice. This study for the first time reported the structure of polysaccharides in B. striata fresh tubers. The results demonstrated that BSPS could be explored as a novel natural wound-healing drug.

A Novel Multiepitope Fusion Antigen as a Vaccine Candidate for the Prevention of Enterotoxigenic E. coli-Induced Calf Diarrhea.

Calf diarrhea caused by enterotoxigenic E. coli (ETEC) poses an enormous economic challenge in the cattle industry. Fimbriae and enterotoxin are crucial virulence factors and vaccine targets of ETEC. Since these proteins have complicated components with large molecular masses, the development of vaccines by directly expressing these potential targets is cumbersome Therefore, this study aimed to develop a multiepitope fusion antigen designated as MEFA by integrating major epitopes of FanC and Fim41a subunits and a toxoid epitope of STa into the F17G framework. The 3D modeling predicted that the MEFA protein displayed the epitopes from these four antigens on its surface, demonstrating the desired structural characteristics. Then, the MEFA protein was subsequently expressed and purified for mouse immunization. Following that, our homemade ELISA showed that the mouse antiserum had a consistent increase in polyclonal antibody levels with the highest titer of 1:217 to MEFA. Furthermore, the western blot assay demonstrated that this anti-MEFA serum could react with all four antigens. Further, this antiserum exhibited inhibition on ETEC adhesion to HCT-8 cells with inhibitory rates of 92.8%, 84.3%, and 87.9% against F17+, F5+, and F41+ ETEC strains, respectively. Additionally, the stimulatory effect of STa toxin on HCT-8 cells was decreased by approximately 75.3% by anti-MEFA serum. This study demonstrates that the MEFA protein would be an antigen candidate for novel subunit vaccines for preventing ETEC-induced diarrhea in cattle.

Active fractions from Jingfang Baidu Powder alleviate Klebsiella-induced Pneumonia by inhibiting TLR4/Myd88-ERK signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Jingfang Baidu Powder (JFBDP) is a classic traditional Chinese medicine prescription. Although Jingfang Baidu powder obtained a general consensus on clinical efficacy in treating pneumonia, there were many Chinese herbal drugs in formula, complex components, and large oral dosage, which brings certain obstacles to clinical application. AIM OF THE STUDY: Therefore, screening of the active fraction that exerts anti-pneumonia helps improve the pharmaceutical preparation, improve the treatment compliance of patients, and further contribute to the clinical application, and the screening of the new active ingredients with anti-pneumonia. The histopathological observation, real-time quantitative PCR, western blotting, and immunofluorescence were applied to evaluate the anti-pneumonia efficacy of active fractions from JFBDP. RESULTS: Three fractions from JFBDP inhibit the gene expression of IL-1ß, IL-10, CCL3, CCL5, and CCL22 in lung tissue infected by Klebsiella at various degrees, and presented a good dose-response relationship. JF50 showed stronger anti-inflammatory effects among three fractions including JF30, JF50, and JF75. Besides, JF50 significantly reduced the protein expression of TLR4 and Myd88 in lung tissue infected with Klebsiella, and it also significantly inhibited p-ERK and p-NF-κB p65. JF50 significantly inhibits the protein expression of Caspase 3, Caspase 8, and Caspase 9 in lung tissue infected with Klebsiella at the dose of 25 mg/kg and 50 mg/kg. CONCLUSION: JF50 improves lung pathological damage in Klebsiella pneumonia mice by inhibiting the TLR4/Myd88/NF-κB-ERK signaling pathway, and inhibiting apoptosis of lung tissue cells. These findings provide a reference for further exploring the active substance basis of Jingfang Baidu Powder in treating bacterial pneumonia.