Local administration of icariin contributes to peripheral nerve regeneration and functional recovery

Abstract

Our previous study showed that systemic administration of the traditional Chinese medicine Epimedium extract promotes peripheral nerve regeneration. Here, we sought to explore the therapeutic effects of local administration of icariin, a major component of Epimedium extract, on peripheral nerve regeneration. A poly(lactic-co-glycolic acid) biological conduit sleeve was used to bridge a 5 mm right sciatic nerve defect in rats, and physiological saline, nerve growth factor, icariin suspension, or nerve growth factor-releasing microsphere suspension was injected into the defect. Twelve weeks later, sciatic nerve conduction velocity and the number of myelinated fibers were notably greater in the rats treated with icariin suspension or nerve growth factor-releasing microspheres than those that had received nerve growth factor or physiological saline. The effects of icariin suspension were similar to those of nerve growth factor-releasing microspheres. These data suggest that icariin acts as a nerve growth factor-releasing agent, and indicate that local application of icariin after spinal injury can promote peripheral nerve regeneration.

Stimulatory effect of icariin on the proliferation of neural stem cells from rat hippocampus

“…Despite the reports that ICA stimulates the proliferation and differentiation of the stem cells in vitro [ 13 , 14 ], little is known on the effect of ICA on neural stem cells proliferation. In the present study, we prepared neural stem cells from rat hippocampus, and confirmed the properties of the proliferation and differentiation of the neural stem cells, and demonstrated that ICA significantly augments the growth and proliferation of the primary neural stem cells.…”

“…It has been reported that ICA stimulates the proliferation and differentiation of human bone mesenchymal stem cells promoting bone formation [ 11 , 12 ]. Recent studies demonstrated that local administration of icariin inhibits neuron apoptosis and promote the regeneration of peripheral nerve and functional recovery [ 13 , 14 ]. However, whether ICA can regenerate neuronal cells and improve the function of neurodegenerative disorders through potentiating the proliferation and differentiation of neural stem cells remains unknown.…”

Mechanism of Action of Icariin in Bone Marrow Mesenchymal Stem Cells

“…Since ALP (an early marker of osteogenic differentiation) levels peak on the 14 th day of the in vitro BMSC culture with ICA [121, 126, 135], it is reasonable to consider 14 days of intravenous ICA administration for the treatment regimen. ICA also promotes the regeneration of periodontal tissue [137], peripheral nerves [138], neural stem cells [139], and endometrium [140], although the optimal concentration of ICA differs across tissues.…”

Control-released basic fibroblast growth factor-loaded poly-lactic-co-glycolic acid microspheres promote sciatic nerve regeneration in rats

“…Peripheral nerve injury occurs in ~2.8% of trauma patients (3) and various methods have previously been used to repair this in a clinical setting (4–6). However, the most effective approach for the regeneration of nerve defects remains to be elucidated.…”

“…Peripheral nerve injury is typically caused by accidents, contusion, compression, tumour resection or congenital deformities and may result in total or partial loss of motor, sensory and autonomic functions ( 1 , 2 ). Peripheral nerve injury occurs in ~2.8% of trauma patients ( 3 ) and various methods have previously been used to repair this in a clinical setting ( 4 – 6 ). However, the most effective approach for the regeneration of nerve defects remains to be elucidated.…”