[Primary study on effect of various components of modified formula radix hedysari on peripheral nerve regeneration]

To investigate the effects of icariin and mixed prescription of icariin, radix hedysari polysaccharide, and liquid extracted from earthworm on peripheral nerve regeneration.

Twenty male SD rats weighing (200 +/- 10) g were selected and randomized into four groups (n=5 per group): sham operated group (group A), model group (group B), icariin group (group C), and mixed liquid group (group D). In group A, the left sciatic nerves of the rats were only exposed, and treated at fixed time from the following day with the NS (2 mL/d). In groups B, C, D, the models were made by clamping sciatic nerve and treated with NS, icariin and mixed liquid, respectively (2 mL/d). The general state of animals was observed after the treatment daily. The nerve function index, motor nerve conductive velocity and the amorphous and number of myelinated sciatic nerve fibers were measured at 21 days.

Animals in various groups were all in good state. After 21 days, the weights of rats in groups A, B, C and D were (366.9 +/- 14.0), (370.1 +/- 16.3), (373.3 +/- 19.6) and (374.0 +/- 11.4) g, respectively, and there was no significant difference among these groups (P > 0.05). For sciatic function index, there was no significant difference between group A and group D (P > 0.05), between group B and group C (P > 0.05), while there was significant difference between group B and group D (P < 0.05). For tibial function index, there was significant difference between group A and groups B, C, D (P < 0.05), there was no significant difference between group B and groups C, D (P > 0.05). For peroneal function index, there was no significant difference between group A and groups C, D (P > 0.05), between group B and groups C, D (P > 0.05). The sciatic motor nerve conductive velocities of group A, B, C and D were (45.0 +/- 2.9), (8.0 +/- 2.6), (13.4 +/- 6.8), and (19.6 +/- 9.3) m/s, respectively, there was no significant difference between group B and group C (P > 0.05), and there was significant difference between group A and groups B, C, D and between group B and group D (P < 0.05). The size of individual myelinated sciatic nerve fibers of regenerated nerves in groups B, C, and D was significantly smaller than that in group A. Comparing with group A, the number of myelinated sciatic nerve fibers in groups B, C, and D was 93.3% +/- 35.6%, 90.6% +/- 37.1%, and 115.4% +/- 40.6%, respectively, but there was no significant difference among four groups (P > 0.05).

Icariin and mixed prescription are safe. The improving peripheral nerve regeneration effect of mixed prescription is more obvious than that of icariin, indicating the comprehensive study of modified formula radix hedysari is necessary to find the effective part or mixture of effective compounds with fixed percentage.