The Healing Effects of Thymoquinone and Dexpanthenol in Sciatic Nerve Compression Injury in Rats.

Introduction: Functional healing of peripheral nerve injuries is still difficult. In this study, potential healing effects of thymoquinone and dexpanthenol in sciatic nerve compression injury (SCI) were investigated. Method: Twenty-four male Wistar albino rats which were applied compression injury to their sciatic nerves were randomly separated into four groups as following: "control" group contained six rats administered no pharmacological agent; "TMK" group consisted of six rats administered 10 mg/kg intraperitoneal thymoquinone once a day for one week; "DXP" group contained six rats administered 50 mg/kg intraperitoneal dexpanthenol once a day for one week; and "TMK-DXP" group consisted of six rats administered separately 10 mg/kg intraperitoneal thymoquinone and 50 mg/kg intraperitoneal dexpenthanol once a day for one week. Four weeks later from SCI, sciatic nerve function index (SFI) was applied before sacrifice of all rats, and then their crushed sciatic nerves were histopathologically examined, in terms of "Schwann cell count", "axon and myelin degeneration", "axon shape/size differences", "fibrosis", and "neovascularisation". Results: "Schwann cell count" (p = 0.011), "axon and myelin degeneration" (p = 0.001), "axon shape/size differences" (p = 0.011), and "fibrosis and neovascularisation" (p = 0.026) scores were different between the control and TMK-DXP groups. SFI scores were different between the control and TMK groups (p = 0.002), between the control and TMK-DXP groups (p < 0.001), and between the DXP and TMK-DXP groups (p = 0.029). Conclusions: This study results revealed that these pharmacological agents used alone had no histopathological healing effect in rats with SCI, but thymoquinone could improve walking function. However, thymoquinone and dexpanthenol used together had a significant histopathological and functional healing effect.