The chemotherapeutic agent
paclitaxel (PTX) causes
peripheral neuropathy as a major dose-limiting side effect, and this
peripheral neuropathy is difficult to control. Our previous report showed that prophylactic repetitive administration of
goshajinkigan ( niú chē shèn qì wán), but not
hachimijiogan ( bā wèi dì huáng wán), which lacks two of the constituents of
goshajinkigan, inhibited PTX-induced
mechanical allodynia in mice. Thus, the
herbal medicines Plantaginis Semen ( chē qián zǐ) or Achyranthis Radix ( niú xī) may contribute to the inhibitory action of
goshajinkigan on the exacerbation of PTX-induced
mechanical allodynia [Andoh et al, J. Tradit.
Complement. Med. 2014; 4: 293-297]. Therefore, in this study, we examined whether an extract of
Plantaginis Semen (EPS) or Achyranthis Radix (EAR) would relieve PTX-induced
mechanical allodynia in mice. A single
intraperitoneal injection of PTX caused
mechanical allodynia, which peaked on day 14 after injection. Repetitive
oral administration of EPS, but not EAR, starting from the day after PTX injection significantly inhibited the exacerbation of PTX-induced
mechanical allodynia. Repetitive
intraperitoneal injection of
aucubin, one of the main components of EPS, starting from the day after PTX injection also significantly reduced PTX-induced
mechanical allodynia. However, repetitive
intraperitoneal injection of
geniposide acid (a precursor of
aucubin) or
catalpol (a metabolite of
aucubin) did not prevent the exacerbation of
mechanical allodynia. These results suggest that prophylactic administration of EPS is effective for preventing the exacerbation of PTX-induced
allodynia.
Aucubin may contribute to the inhibitory action of EPS on the exacerbation of PTX-induced
allodynia.