TY - JOUR
T1 - Methylene blue induces an analgesic effect by significantly decreasing neural firing rates and improves pain behaviors in rats
AU - Lee, Seung Won
AU - Moon, Sun Wook
AU - Park, Jin Sung
AU - Suh, Hye Rim
AU - Han, Hee Chul
N1 - Funding Information:
This research was supported by Basic Science Research Program through the National Research Foundation of Korea ( NRF ) funded by the Ministry of Education (grant number: NRF-2019R1I1A1A01063196).
PY - 2021/2/19
Y1 - 2021/2/19
N2 - Methylene blue (MB) is a blue cationic thiazine dye and currently used in different medical settings. Notably, there have been several attempts to introduce MB for attenuating pain in the last decade. Some clinical studies reported remarkable results, which, however, have been much debated. In addition, accumulating evidence have revealed that MB diminishes voltage-gated sodium channel currents. Accordingly, in the present study, we conducted in vivo experiments, including in vivo single nerve recording and behavioral test, to investigate whether MB dampens neural firing rates and ultimately contributes to pain relief. As a result, neural firing rates significantly decreased and finally converged to zero after MB administration. This event lasted longer than that of lidocaine and was dose-dependently modulated. Furthermore, there was a marked improvement in pain behaviors. The withdrawal threshold and latency of hind paws significantly rose post-MB administration. Therefore, these results demonstrate that MB lessens pain by significantly weakening neural excitability, which implies a strong possibility that this dye may be developed as a pain-relieving medication in the future. This is the first in vivo study to elucidate the effect of MB on nerves and pain relief.
AB - Methylene blue (MB) is a blue cationic thiazine dye and currently used in different medical settings. Notably, there have been several attempts to introduce MB for attenuating pain in the last decade. Some clinical studies reported remarkable results, which, however, have been much debated. In addition, accumulating evidence have revealed that MB diminishes voltage-gated sodium channel currents. Accordingly, in the present study, we conducted in vivo experiments, including in vivo single nerve recording and behavioral test, to investigate whether MB dampens neural firing rates and ultimately contributes to pain relief. As a result, neural firing rates significantly decreased and finally converged to zero after MB administration. This event lasted longer than that of lidocaine and was dose-dependently modulated. Furthermore, there was a marked improvement in pain behaviors. The withdrawal threshold and latency of hind paws significantly rose post-MB administration. Therefore, these results demonstrate that MB lessens pain by significantly weakening neural excitability, which implies a strong possibility that this dye may be developed as a pain-relieving medication in the future. This is the first in vivo study to elucidate the effect of MB on nerves and pain relief.
KW - In vivo single nerve recording
KW - Lidocaine
KW - Methylene blue
KW - Neural firing rate
KW - Pain reduction
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U2 - 10.1016/j.bbrc.2021.01.008
DO - 10.1016/j.bbrc.2021.01.008
M3 - Article
AN - SCOPUS:85099296355
VL - 541
SP - 36
EP - 42
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
ER -