Background: The effect of systemic and local peptide treatment effective in muscle contusion and then on counteraction of corticosteroid-induced impairment was tested. The pentadecapeptide BPC 157, given without a carrier, improved the healing of transected quadriceps muscle. It also improved muscle healing in rats with muscle crush injury when applied systemically or locally. Importantly, it counteracted corticosteroid-impairment in tendon to bone healing. Thus BPC 157 is proposed as an effective treatment that can improve muscle healing in spite of corticosteroid treatment.
Material and Method: After the gastrocnemius muscle complex had been injured, rats received BPC 157 (intraperitoneally or locally as a cream) and/or 6alpha-methylprednisolone (intraperitoneally) only once (immediately after injury, sacrifice at 2 h) or once daily (final dose 24 hours before sacrifice and/or assessment procedure at days 1, 2, 4, 7, and 14). Muscle healing was evaluated functionally, macroscopically, and histologically.
Results: Without therapy, crushed gastrocnemius muscle complex controls showed limited improvement. 6alpha-methylprednisolone markedly aggravated healing. In contrast, BPC 157 induced faster muscle healing and full function restoration and improved muscle healing despite systemic corticosteroid treatment when given intraperitoneally or locally and demonstrated functionally, macroscopically, and histologically at all investigated intervals.
Conclusions: BPC 157 completely reversed systemic corticosteroid-impaired muscle healing.

Keywords: Proteins - pharmacology, Peptide Fragments - pharmacology, Muscles - pathology, Muscle Fibers, Skeletal - pathology, Male, Injections, Intraperitoneal, Desmin - metabolism, Inflammation - pathology, Cell Nucleus - metabolism, Animals, Adrenal Cortex Hormones - adverse effects, Administration, Topical, Rats, Rats, Wistar, Wound Healing - drug effects