Earthworm protein extract PVESD promotes diabetic wound healing through synergistic regulation of TLR/NF-κB and AMPK...

Diabetic wound healing is severely impaired by a vicious cycle of metabolic dysfunction and chronic inflammation, posing a significant clinical challenge with limited existing treatments. Earthworms are used for wound healing in Traditional Chinese Medicine, but their precise mechanisms in diabetes remain unclear.

Herein, we investigated the therapeutic potential and mechanisms of PvESD, an earthworm-derived protein extract, in diabetic wound healing.

A full-thickness wound model was established in db/db mice. Wound closure, histology, and immunofluorescence were analyzed. Proteomic analysis identified key pathways, which were validated by western blotting. In vitro studies using HUVECs, NIH3T3 cells, and RAW264.7 cells employed functional assays.

PvESD significantly accelerated diabetic wound healing and enhanced re-epithelialization, collagen deposition, and angiogenesis in vivo. Proteomic and functional studies revealed a novel dual-axis mechanism. PvESD concurrently activated the AMPK/Sirt1/eNOS pathway to promote vascular repair and restore metabolic homeostasis while inhibiting the TLR/NF-κB pathway to resolve persistent inflammation. In vitro, PvESD protected HUVECs and NIH3T3 cells from advanced glycation end products-induced damage, restored cellular function, and suppressed lipopolysaccharide-induced inflammation in RAW264.7 cells. Importantly, AMPK inhibition did not abolish the anti-inflammatory effect of PvESD, indicating the independence and synergy of the two regulatory axes.

The earthworm protein extract PvESD effectively promotes diabetic wound healing through a synergistic dual-axis mechanism that coordinately modulates the AMPK-mediated metabolic-repair axis and the TLR/NF-κB-driven inflammatory axis. This work provides a modern pharmacological understanding of traditional remedies, and proposes a promising multitarget therapeutic strategy for complex chronic wounds.