Single-cell RNA sequencing reveals that Danggui Buxue Tang decoction facilitates wound healing after anal fistula by promoting M2 macrophage polarization

BACKGROUND: We aim to employ single-cell RNA (scRNA) sequencing technology to investigate potential regulatory mechanism of Danggui Buxue Tang (DBT) in wound healing for its utilization in post-anal fistula surgery recovery. METHODS: Fistula-like wound model in mice was established and administered DBT to assess its effects. Mice were divided into control and DBT groups and collected samples on the first day and 7th day after model establishment. The DBT was prepared from Astragalus membranaceus and Angelica sinensis. ScRNA sequencing was performed on each group. RESULTS: Our results showed that DBT treatment obviously reduced wound area in mice with anal fistula through activation of OPN/PI3K/Akt/eNOS signaling. Furthermore, the results of scRNA sequencing showed that all cells were clustered into 7 types, and the macrophages were categorized into 13 distinct clusters. In the early stages of wound formation, M1-like macrophages (M1C1) abundant in both groups at day1. However, by day 7 post-injury, the DBT-treated group exhibited a reduction in the infiltration of M1-like macrophages (M1C1) compared to the model group. Conversely, the proportion of M2-like macrophages (M2C3) showed a marked increase in the DBT group at day 7, while decreasing in the model group. Pseudo-time trajectory analysis confirmed that DBT treatment modulates macrophage polarization, potentially enhancing the wound healing process by promoting a transition from pro-inflammatory to anti-inflammatory macrophage populations. CONCLUSION: DBT has the potential to accelerate wound healing after anal fistula by promoting M2 macrophage polarization, likely through activation of the PI3K/Akt signaling pathway.