L-tetrahydropalmatine reduces oxaliplatin-induced neurotoxicity by
selectively inhibiting the transporter-mediated uptake in the dorsal
root ganglion
Yaodong Yi
Zhejiang University, College of Pharmaceutical Sciences 866 Yuhangtang Road, Hangzhou 310058, China Hangzhou, Zhejiang, CN 310058 (86)-571-88208404 Hangzhou, CN Hangzhou, CN
Corresponding Author:472847266@qq.com
Author ProfileAbstract
Background and Purpose Oxaliplatin (OXA) is a third-generation
anti-tumour platinum drug; however, the high accumulation of OXA in the
dorsal root ganglia (DRG) induces severe peripheral neurotoxicity, which
limits its application. This study aims to confirm the role of OCT2,
OCTN1, and OCTN2 in the transcellular transport of OXA and to explore
whether L-tetrahydropalmatine (L-THP) would selectively inhibit the
uptake transporters and subsequently alleviate OXA-induced peripheral
neurotoxicity. Experimental Approaches Transporter-transfected MDCK
cells, primary DRG cells and tumour cell lines were utilized in vitro
studies. OXA-induced chronic peripheral neurotoxicity mice and
tumour-bearing nude mice were used in vivo studies. Key Results OCT2 and
OCTN1 but not OCTN2 were involved in the uptake of OXA; OCT2 played the
most important role. L-THP reduced the cytotoxicity and cellular
accumulation of OXA in a concentration-dependent manner in MDCK-hOCT2,
MDCK-hOCTN1, and rat primary DRG cells but did not affect its efflux
from MDCK-hMRP2 cells. Furthermore, L-THP attenuated OXA-induced
peripheral neurotoxicity and reduced the platinum concentration in the
DRG in mice in a dose-dependent manner. L-THP did not reduce the
platinum concentration in the tumours and did not impair the antitumour
efficacy of OXA in HT29 tumour-bearing nude mice nor in tumour cells
(HT29 and SW620 cells). Conclusion and Implications OCT2 and OCTN1,
especially OCT2, contribute to OXA uptake in the DRG. L-THP attenuates
OXA-induced peripheral neurotoxicity via inhibiting OCT2 and OCTN1 but
without impairing the antitumour efficacy of OXA. L-THP is a potential
candidate drug to attenuate OXA-induced peripheral neurotoxicity.