Exploration of the immuno-adjuvant effect and mechanism of Anemoside B4 through network pharmacology and experiment verification

Recently, the Department of Clinical Veterinary Medicine, College of Veterinary Medicine, Sichuan Agricultural University published the article " Exploration of the immuno-adjuvant effect and mechanism of Anemoside B4 through network pharmacology and experiment verification”published on the Phytomedicine (online link: https://doi.org/10.1016/j.phymed.2023.155302). This study is the first comprehensive study of the mechanism of Anemoside B4 in the field of immuno-adjuvants. The results of this study provide an important scientific basis for the clinical application of anemoside B4 in animal vaccines, and open up new research ideas for improving the immune effect of vaccines. The first author Luo Hao and Fan Lei are the co-first authors, and Associate Professor Shen Liuhong is the corresponding author and instructor.

Background: Extensive investigation has been undertaken about the utilization of saponin adjuvants in vaccines intended for veterinary and human applications. AB4 is the main constituent of the traditional Chinese medicine, Pulsatilla chinensis (Bunge) Regel, and has immunomodulatory activity. However, there is a paucity of reports on AB4 as a potential adjuvant.

Purpose: The objective of this work was to clarify the adjuvant role of AB4 and the molecular mechanisms that underlie its immunomodulatory actions.

Study design and methods: The immunomodulatory effects of AB4 were investigated using network pharmacological analyses. These effects were validated by evaluating the developmental status of the immune organs and by using the following techniques: ELISA for the quantification of serum-specific antibodies to determine immune-related cytokine levels; the MTS method for the assessment of proliferative activity of splenic lymphocytes; flow cytometry to analyze lymphocyte and dendritic cell activation status; and western blotting for mechanistic analysis at the protein level.

Results: The network pharmacological analysis predicted a total of 52 targets and 12 pathways for AB4 to exert immunomodulatory effects. In a mouse model with immunity to OVA, the introduction of AB4 resulted in the enhancement of immunological organ growth and maturation, elevation of blood antibodies targeting OVA, and amplification of the production of cytokines associated with Th1 and Th2 immune responses. Additionally, the administration of AB4 resulted in a notable augmentation of lymphocyte proliferation and an elevation in the CD4+/CD8+ T lymphocyte ratios. Furthermore, the administration of AB4 enhanced the maturation process of DCs in the draining LNs and increased the production of co-stimulatory factors and MHC II molecules. AB4 induces the upregulation of TLR4 and IKK proteins, as well as the phosphorylation of NF-κB p65 protein within the TLR4/NF-κB signaling cascade, while concurrently suppressing the expression of IκBα protein.

Conclusion: The specific immunoadjuvant effects of AB4 have been demonstrated to modulate the growth and maturation of immune organs and enhance the secretion and cellular activity of pertinent immune molecules. The utilization of network pharmacology, combined within and in vivo vitro assays, clarified the adjuvant function of AB4, which potentially involves the regulation of the TLR4/NF-κB signaling pathway.

Figure1 The immune adjuvant effect of Anemoside B4 and its mechanism Abstract

Figure2 The immune adjuvant effect of Anemoside B4 and its mechanism