title: Glycyrrhizin improves p75NTR-associated sciatic nerve regeneration in a BALB/c mouse model.
abstract: Glycyrrhizin has a role in immune regulation in the central nervous system, but its impact on sciatic nerve injury had not previously been reported. In this study, a BALB/c mouse model of sciatic nerve injury was used to explore the role of glycyrrhizin in sciatic nerve repair and its underlying mechanism. Glycyrrhizin with intragastric gavage of 10 and 20 mg/kg weight per day (mid- and high-dose, respectively) inhibited p75 neurotrophin receptor (p75NTR) expression at the protein and mRNA levels versus the 5 mg/kg (low-dose) group and control (0.9% NaCl solution) at one, two, four and eight weeks following sciatic nerve injury, and simultaneously improved the action potential amplitude and motor nerve conductive velocity. Combined Marsland, Glees and Erikson's silver stain and Luxol fast blue staining results indicated that high- and mid-dose glycyrrhizin promoted improved sciatic nerve myelination compared with the low-dose or control groups eight weeks after injury. Immunofluorescence staining demonstrated that glycyrrhizin had an inhibitory effect to a certain degree on local hypertrophic scar and inflammatory responses in the mouse model. In conclusion, glycyrrhizin can promote sciatic nerve regeneration and functional repair, in which doses of 10 and 20 mg/kg per day are more effective than lower doses, and such regeneration is associated with the downregulation of p75NTR.
authors.affiliation: Department of Orthopaedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China.
authors.forename: Yu-Xi
authors.initials: YX
authors.lastname: Jia
authors.affiliation: Jilin University Bethune School of Medical Sciences, Changchun, Jilin 130021, P.R. China.
authors.forename: Jin-Ran
authors.initials: JR
authors.lastname: Li
authors.affiliation: Department of Orthopaedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China.
authors.forename: Cui-Ying
authors.initials: CY
authors.lastname: Mao
authors.affiliation: Department of Orthopaedics, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China.
authors.forename: Wei-Tian
authors.initials: WT
authors.lastname: Yin
authors.affiliation: Department of Dermatology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, P.R. China.
authors.forename: Ri-Hua
authors.initials: RH
authors.lastname: Jiang
keywords: glycyrrhizin; p75 neurotrophin receptor; peripheral nerve injury; regeneration; sciatic nerve