Long Ya Cao (Agrimonia pilosa Ledeb.) extract and its bioactive constituent (agrimonolide) attenuate chronic inflammation and accelerate wound healing in rats through regulating oxidative-inflammatory markers and stimulating collagen production

Introduction In Traditional Chinese Medicine, Agrimonia pilosa (AP) is widely consumed as tea decoction and has traditionally been used for its hemostatic, astringent, and anti-swelling properties. Agrimonolide (AG), a major coumarin isolated from A. pilosa extract (APE), has demonstrated anti-inflammatory activity in an in vitro assay, although its efficacy in in vivo models remains unexplored. Furthermore, the wound healing activity of both APE and AG has not yet been systematically investigated. Therefore, the current study aimed to investigate the anti-inflammatory and wound healing effects of APE and AG in in vivo models, supported by molecular docking analysis. Methods AG was isolated and characterized from APE by column chromatography. Both APE and AG were formulated as topical gels and evaluated for acute dermal toxicity. Anti-inflammatory efficacy was evaluated in carrageenan (CAR)-induced acute and Complete Freund's Adjuvant (CFA)-induced chronic inflammation models, and wound healing activity was evaluated using an excision-induced wound. Biochemical markers for inflammation (TNF-α, IL-6), oxidative stress (LPO, SOD, GSH), and extracellular matrix components (hydroxyproline, hexosamine, protein) were examined, alongside histopathology. The docking interactions of AG with GSK-3, TNF-α, and IL-6 were evaluated. Results Topical application of APE (2000 mg/kg) and AG (200 mg/kg) caused minimal irritation in rats, with no behavioral abnormalities or death. Treatment with APE-Gel (10%) and AG-Gel (0.5%), when compared with the negative control, effectively reduced ( p < 0.05) CAR and CFA-induced paw edema by 37-40% and 24-27%, respectively. Furthermore, APE-Gel (10%) and AG-Gel (0.5%) treatment accelerated wound closure by more than 85% by day 21. APE and AG treatment, in contrast to the negative control showed increased ( p < 0.05) hydroxyproline, protein, and antioxidant levels (SOD, GSH), while reducing ( p < 0.05) LPO, TNF-α, and IL-6 levels. Histological findings confirmed protection against inflammation and wound-induced tissue damage. In silico molecular docking predicted binding energies of −52.34, −59.36, and −71.86 kcal/mol for AG against GSK-3, TNF-α, and IL-6, respectively, showing more favorable binding than the reference drugs toward GSK-3 and TNF-α, but not IL-6. Conclusion APE and AG exhibited significant anti-inflammatory and wound healing activities by modulating cytokine release, oxidative stress, and enhancing collagen production. Nevertheless, these findings are based on preclinical models, and further mechanistic and clinical studies are required to validate their therapeutic potential.