Exploring the Effects of Tomatidine ((3β, 5α, 22β, and 25β)-Spirosolan-3-ol) on Voltage-gated Na+ currents: Insights Into Its Ionic Mechanisms of Action on Current Magnitude, Gating, and Frequency Dependence

Tomatidine, a major tomato glycoalkaloid, is effective for the prevention of skeletal muscle wasting and enhancing mitophagy. However, its effects on transmembrane ionic currents are not well explored. In this study, we explored the interactions between tomatidine and Na+ current. GH3 or Neuro-2a ce...

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Main Authors: Tso-Lin Lin, Edmund Cheung So, Sheng-Nan Wu
Format: Article
Language:English
Published: Wolters Kluwer Medknow Publications 2024-12-01
Series:Journal of Physiological Investigation
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Online Access:https://journals.lww.com/cjop/fulltext/2024/67060/exploring_the_effects_of_tomatidine___3_,_5_,_22_,.2.aspx
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author Tso-Lin Lin
Edmund Cheung So
Sheng-Nan Wu
author_facet Tso-Lin Lin
Edmund Cheung So
Sheng-Nan Wu
author_sort Tso-Lin Lin
collection DOAJ
description Tomatidine, a major tomato glycoalkaloid, is effective for the prevention of skeletal muscle wasting and enhancing mitophagy. However, its effects on transmembrane ionic currents are not well explored. In this study, we explored the interactions between tomatidine and Na+ current. GH3 or Neuro-2a cells were used for recording the ion currents employing modified patch-clamp technique under whole-cell configuration. Tomatidine increased both the peak, (transient Na+ current [INa (T)]) and sustained (late Na+ current [INa (L)]) components of voltage-gated Na+ current (INa) in a concentration-dependent manner, with the concentration required for 50% stimulation values of 43.3 μM and 3.1 μM, respectively. The steady-state current-voltage relationship of INa (T) remained unchanged; however, the steady-state inactivation curve of INa (T) in the presence of 3 μM tomatidine was shifted to less depolarized potential by around 6 mV. Tomatidine enhanced the window INa (window Na+ current [INa (W)]), which were attenuated by the ranolazine (Ran) and carbamazepine (CBZ). During a train of depolarizing pulses, tomatidine slowed the exponential decay of INa (T), and this effect was reversed by Ran or dapagliflozin. Tomatidine increased both fast and slow recovery time constants from INa (T) block, affecting the recovery time course. Tomatidine increased the amplitude of persistent Na+ current in response to a sinusoidal waveform. In neuro-2a cells, tomatidine increased INa (T) amplitude and slowed its inactivation, with this effect being attenuated by Ran or CBZ. In conclusion, tomatidine enhanced magnitude and modified its gating behaviors.
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spelling doaj-art-51790164c67140fa9af315b0251ec8772025-01-16T10:31:11ZengWolters Kluwer Medknow PublicationsJournal of Physiological Investigation2950-63442950-63522024-12-0167629831110.4103/ejpi.EJPI-D-24-00076Exploring the Effects of Tomatidine ((3β, 5α, 22β, and 25β)-Spirosolan-3-ol) on Voltage-gated Na+ currents: Insights Into Its Ionic Mechanisms of Action on Current Magnitude, Gating, and Frequency DependenceTso-Lin LinEdmund Cheung SoSheng-Nan WuTomatidine, a major tomato glycoalkaloid, is effective for the prevention of skeletal muscle wasting and enhancing mitophagy. However, its effects on transmembrane ionic currents are not well explored. In this study, we explored the interactions between tomatidine and Na+ current. GH3 or Neuro-2a cells were used for recording the ion currents employing modified patch-clamp technique under whole-cell configuration. Tomatidine increased both the peak, (transient Na+ current [INa (T)]) and sustained (late Na+ current [INa (L)]) components of voltage-gated Na+ current (INa) in a concentration-dependent manner, with the concentration required for 50% stimulation values of 43.3 μM and 3.1 μM, respectively. The steady-state current-voltage relationship of INa (T) remained unchanged; however, the steady-state inactivation curve of INa (T) in the presence of 3 μM tomatidine was shifted to less depolarized potential by around 6 mV. Tomatidine enhanced the window INa (window Na+ current [INa (W)]), which were attenuated by the ranolazine (Ran) and carbamazepine (CBZ). During a train of depolarizing pulses, tomatidine slowed the exponential decay of INa (T), and this effect was reversed by Ran or dapagliflozin. Tomatidine increased both fast and slow recovery time constants from INa (T) block, affecting the recovery time course. Tomatidine increased the amplitude of persistent Na+ current in response to a sinusoidal waveform. In neuro-2a cells, tomatidine increased INa (T) amplitude and slowed its inactivation, with this effect being attenuated by Ran or CBZ. In conclusion, tomatidine enhanced magnitude and modified its gating behaviors.https://journals.lww.com/cjop/fulltext/2024/67060/exploring_the_effects_of_tomatidine___3_,_5_,_22_,.2.aspxcurrent recoverylate na+ currentneuroblastoma cellpersistent na+ currentpituitary cellpulse train stimulationsinusoidal stimulationtomatidinetransient na+ currentvoltage-gated na+ currentwindow na+ current
spellingShingle Tso-Lin Lin
Edmund Cheung So
Sheng-Nan Wu
Exploring the Effects of Tomatidine ((3β, 5α, 22β, and 25β)-Spirosolan-3-ol) on Voltage-gated Na+ currents: Insights Into Its Ionic Mechanisms of Action on Current Magnitude, Gating, and Frequency Dependence
Journal of Physiological Investigation
current recovery
late na+ current
neuroblastoma cell
persistent na+ current
pituitary cell
pulse train stimulation
sinusoidal stimulation
tomatidine
transient na+ current
voltage-gated na+ current
window na+ current
title Exploring the Effects of Tomatidine ((3β, 5α, 22β, and 25β)-Spirosolan-3-ol) on Voltage-gated Na+ currents: Insights Into Its Ionic Mechanisms of Action on Current Magnitude, Gating, and Frequency Dependence
title_full Exploring the Effects of Tomatidine ((3β, 5α, 22β, and 25β)-Spirosolan-3-ol) on Voltage-gated Na+ currents: Insights Into Its Ionic Mechanisms of Action on Current Magnitude, Gating, and Frequency Dependence
title_fullStr Exploring the Effects of Tomatidine ((3β, 5α, 22β, and 25β)-Spirosolan-3-ol) on Voltage-gated Na+ currents: Insights Into Its Ionic Mechanisms of Action on Current Magnitude, Gating, and Frequency Dependence
title_full_unstemmed Exploring the Effects of Tomatidine ((3β, 5α, 22β, and 25β)-Spirosolan-3-ol) on Voltage-gated Na+ currents: Insights Into Its Ionic Mechanisms of Action on Current Magnitude, Gating, and Frequency Dependence
title_short Exploring the Effects of Tomatidine ((3β, 5α, 22β, and 25β)-Spirosolan-3-ol) on Voltage-gated Na+ currents: Insights Into Its Ionic Mechanisms of Action on Current Magnitude, Gating, and Frequency Dependence
title_sort exploring the effects of tomatidine 3β 5α 22β and 25β spirosolan 3 ol on voltage gated na currents insights into its ionic mechanisms of action on current magnitude gating and frequency dependence
topic current recovery
late na+ current
neuroblastoma cell
persistent na+ current
pituitary cell
pulse train stimulation
sinusoidal stimulation
tomatidine
transient na+ current
voltage-gated na+ current
window na+ current
url https://journals.lww.com/cjop/fulltext/2024/67060/exploring_the_effects_of_tomatidine___3_,_5_,_22_,.2.aspx
work_keys_str_mv AT tsolinlin exploringtheeffectsoftomatidine3b5a22band25bspirosolan3olonvoltagegatednacurrentsinsightsintoitsionicmechanismsofactiononcurrentmagnitudegatingandfrequencydependence
AT edmundcheungso exploringtheeffectsoftomatidine3b5a22band25bspirosolan3olonvoltagegatednacurrentsinsightsintoitsionicmechanismsofactiononcurrentmagnitudegatingandfrequencydependence
AT shengnanwu exploringtheeffectsoftomatidine3b5a22band25bspirosolan3olonvoltagegatednacurrentsinsightsintoitsionicmechanismsofactiononcurrentmagnitudegatingandfrequencydependence