Figure 2: Suppression of age-induced demyelination by Chinpi. (A) Toluidine blue staining of cross-sections of the corpus callosum shows age-induced demyelination in control mice (untreated) (a) and the reversal of age-induced demyelination in 26-month-old mice after treatment with Chinpi for 2 months (b). (B) Electron micrographs of cross-sections of the corpus callosum show age-induced demyelination in 26-month old (a) mice. The myelination status was greatly improved after Chinpi treatment for 2 months (b). (C) The density of myelinated fibers per 400 m2 was lower in untreated 26-month-old mice, and treatment with Chinpi led to a significant recovery in the myelinated fiber density. The number of myelinated fibers in each mouse was counted using 4–6 electron micrographs and was averaged. Data represent the mean ± SEM (n = 3); *P < .005. (D) The G-ratio, an indicator of demyelination defined as the ratio of the diameter of the axon to the diameter of the axon plus the surrounding myelin (the formula is shown in the insert), shows that the increased G-ratio in the elderly mice was abrogated by Chinpi treatment. The number of measured axons determined from 3 to 5 mice per group was 54–109 using 8–10 electron micrographs per mouse. Data represent the mean ± SEM. P > .01 versus control.