Figure 1.

Dendropanax morbiferus leaf EtOH extract treatment increased the size of OL membrane sheath in the mixed glial culture as well as pure OL culture. (a–e) Primary mixed glial cultures were treated with the medium containing EtOH or several medicinal plant EtOH extracts during DIV 8–12 and fixed at DIV 12 for MBP staining to analyse the membrane size. Compared with EtOH-treated cultures (a,c), the size of OL membrane sheath was increased by the treatment of medicinal plant extracts including DM (b,d; electronic supplementary material, figure S1). (e) Total summary of MBP-positive percentage area per field depending on the treatment. Among the investigated medicinal plants, ArP and DM induced the highest MBP-positive percentage area per field in the glia mixed culture. (f–n) OPCs were isolated from the mixed glial cultures on DIV 10 and seeded on PDL-coated coverslip. On DIV 1, the OPCs were treated with the EtOH- or the indicated medicinal plant extract-containing medium and fixed on DIV 4 for immunostaining with MBP antibody. Dendropanax morbiferus-treated OPCs showed the highest MBP-positive area per cell, while ArP-treated OPCs indicated the half of the membrane size of DM-treated OPCs. (o) MBP-positive area per cell depending on the indicated plant parts of DM. The leaf showed the highest effects on the increment of the OL membrane size. Bars represent mean ± s.e.m. *p < 0.05; ***p < 0.001; n = 3 experiments, Student's t-test. Scale bars, 100 μm (a–d,f–m).