IL‐23 Receptor Agonism by Mulberroside C Activates the RASGRP1/RAS/ERK Pathway Contributing to Leukopenia Treatments

ABSTRACT Chemotherapy‐ and radiotherapy‐induced leukopenia is a common challenge in cancer treatment, with a significant dearth of effective therapeutic options. IL‐23 receptor (IL‐23R) signaling holds the potential for promoting neutrophil generation and maturation, yet the underlying mechanisms remain elusive. This study investigates the molecular mechanism and efficacy of Mulberroside C (MC) in alleviating leukopenia via IL‐23R signaling. In vitro, flow cytometry, nitroblue tetrazolium reduction assay, and Giemsa staining were employed to evaluate MC's impact on neutrophil differentiation in NB4 and HL‐60 cell lines. The antibacterial activity of MC was assessed using an agar plate assay. In vivo, leukopenia models induced by irradiation and cyclophosphamide were established in zebrafish and mice to determine MC's effect on neutrophil recovery. Mechanistic studies involved RNA sequencing, network pharmacology analysis, molecular docking, quantitative real‐time PCR (qRT‐PCR), and Western blotting to explore the associated signaling pathways. Cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) were used to identify MC's targets. MC significantly enhanced neutrophil maturation in a dose‐dependent manner, facilitating leukopenia recovery. Mechanistically, MC binds to IL‐23R, upregulating G‐CSF , GM‐CSF , and RASGRP1 and activating the RAS/ERK signaling pathway. Notably, the upregulation of RASGRP1 by MC supports the generation of fully functional neutrophils, compared to those induced by G‐CSF and GM‐CSF alone. This study provides the first evidence that MC promotes neutrophil generation and antimicrobial activity through the IL‐23R‐mediated pathway, offering a promising therapeutic strategy for leukopenia.