Kamishoyosan and Shakuyakukanzoto promote recovery from paclitaxel-induced neurite retraction in PC12 cells

Ken Konaka,Masaki Imanishi,Naoto Okada,Shuji Fushitani,Yoshito Zamami,Kota Moriyama,Keisuke Ishizawa,Kazuyoshi Kawazoe,Takumi Sakurada

doi:10.1186/s40780-017-0090-y

Abstract

BackgroundIn chemotherapy, the full round of treatment must be completed as scheduled to achieve the strongest therapeutic effect. However, peripheral neuropathy, a severe side effect of the chemotherapeutic agent paclitaxel, can force the premature discontinuation of treatment. As some kampo practitioners have suggested that it may be possible to counteract such side effects, we analyzed the effects of Kamishoyosan, Shakuyakukanzoto, and Goshajinkigan in an in vitro model of paclitaxel-induced peripheral neuropathy.MethodsPaclitaxel-treated PC12 cells were assessed for neurite length and performed Western blot analysis for growth-associated protein-43 (GAP-43) and light neurofilament protein (NF-L) levels in the presence of nerve growth factor (NGF); they were re-assessed, with additional testing for acetylcholinesterase levels, after application of one of the kampo. We also compared phosphorylation of extracellular signal-regulated kinase (Erk)1/2 and Akt via Western blot analysis. About effect of kampo to anticancer efficacy, we confirmed cell cytotoxicity in A549 cells using MTT assay.ResultsAddition of Kamishoyosan or Shakuyakukanzoto, but not Goshajinkigan, significantly improved neurite length and GAP-43 and NF-L levels from paclitaxel-treated PC12 cells, relative to those of only NGF-treated PC12 cells. The promoting effect of Kamishoyosan and Shakuyakukanzoto in neurite outgrowth is confirmed when NGF promoted neurite outgrowth, and it was inhibited partially when Erk1/2 and Akt were blocked by Erk1/2 inhibitor or Akt inhibitor alone. Furthermore, neurite outgrowth induced by TJ24 and TJ68 was inhibited more strongly when Erk1/2 inhibitor and Akt inhibitor were treated at the same time. NGF with Kamishoyosan or Shakuyakukanzoto promoted the proportion of phosphorylated Erk1/2 and phosphorylated Akt compare with NGF only. On the other hand, Kamishoyosan or Shakuyakukanzoto didn’t influence cytotoxicity of paclitaxel in A549 cells.ConclusionsKamishoyosan or Shakuyakukanzoto promotes neurite outgrowth with NGF via increasing the proportion of phosphorylated Erk1/2 and phosphorylated Akt in PC12 cells. The effect applies to recovery from paclitaxel-induced axonal involvement and might promote recovery from paclitaxel-induced neuropathy without influence of anticancer effect of paclitaxel.

Highlights

In chemotherapy, the full round of treatment must be completed as scheduled to achieve the strongest therapeutic effect
Paclitaxel-induced neuropathy Varying concentrations of paclitaxel were added to PC12 cells, following which cell viability and neurite length were evaluated
A statistically significant increase in the expression of both growth-associated protein-43 (GAP-43) and neurofilament protein (NF-L) was observed for the combinations of nerve growth factor (NGF) and TJ24 or TJ68 (Fig. 2b, c)

Summary

Introduction

The full round of treatment must be completed as scheduled to achieve the strongest therapeutic effect. Paclitaxel, a key chemotherapeutic used against many solid cancers, induces neuropathy as a side effect as frequently as 50% of the time in a cumulative, dose-dependent manner [2, 3]. This neurotoxicity significantly and negatively influences treatment, and may necessitate shortening or otherwise limiting such treatment. Hidaka et al reported that Shakuyakukanzoto may suppress paclitaxel-induced allodynia in vivo, though they were unable to elucidate the mechanisms underlying this effect [5] Another formula, Goshajinkigan, has been reported to potentially reduce oxaliplatin-induced peripheral neuropathy [6, 7]. We further aimed to elucidate the mechanisms underlying these potential effects

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Conclusion