Hemp Oil as a Potential Agent to Promote Achilles Tendon Healing: An In Vivo Study in Rats

Abstract

Achilles tendon rupture is a common injury with prolonged recovery and risk of poor remodeling. Hemp seed oil, rich in cannabidiol, essential fatty acids, and antioxidants, has anti-inflammatory and regenerative potential, yet evidence for its role in tendon healing remains limited. Therefore, the aim of this study was to evaluate the effect of topical hemp oil administration on the healing of surgically induced Achilles tendon rupture in white rats (Rattus norvegicus). Thirty-two adult male rats were randomly assigned to a control group or a treatment group receiving daily topical hemp seed oil following surgically induced partial Achilles tendon rupture. Functional recovery was evaluated on day 18 using footprint analysis, while histological parameters—including tenocyte morphology, vascularization, and collagen organization—were assessed by Bonar scoring. Footprint analysis demonstrated a higher proportion of normal gait in the treatment group compared with controls (75% vs. 62.5%). Histological evaluation revealed elongated tenocytes with more organized collagen fibres and reduced neovascularization in the treatment group, consistent with advanced tendon remodeling. Quantitative analysis showed significantly lower Bonar scores in the treatment group for tenocyte morphology (p=0.002), vascularization (p=0.033), and collagen disorganization (p<0.001). In conclusion, topical hemp seed oil accelerates both functional and structural recovery of the Achilles tendon, supporting its potential role as an adjuvant therapy in tendon injury management.