1. Academic Validation
  2. Characterization of Effectiveness in Concerted Ih Inhibition and IK(Ca) Stimulation by Pterostilbene (Trans-3,5-dimethoxy-4'-hydroxystilbene), a Stilbenoid

Characterization of Effectiveness in Concerted Ih Inhibition and IK(Ca) Stimulation by Pterostilbene (Trans-3,5-dimethoxy-4'-hydroxystilbene), a Stilbenoid

  • Int J Mol Sci. 2020 Jan 5;21(1):357. doi: 10.3390/ijms21010357.
Edmund Cheung So 1 2 Zi-Han Gao 3 Shun Yao Ko 2 Sheng-Nan Wu 3 4 5
Affiliations

Affiliations

  • 1 Department of Anesthesia and Medical Research, An Nan Hospital, China Medical University, Tainan 70965, Taiwan.
  • 2 Graduate Institute of Medical Sciences, Chang Jung Christian University, Tainan 71101, Taiwan.
  • 3 Department of Physiology, National Cheng Kung University Medical College, No. 1, University Road, Tainan 70101, Taiwan.
  • 4 Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 70101, Taiwan.
  • 5 Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan.
Abstract

Pterostilbene (PTER), a natural dimethylated analog of resveratrol, has been demonstrated to produce anti-neoplastic or neuroprotective actions. However, how and whether this compound can entail any perturbations on ionic currents in electrically excitable cells remains unknown. In whole-cell current recordings, addition of PTER decreased the amplitude of macroscopic Ih during long-lasting hyperpolarization in GH3 cells in a concentration-dependent manner, with an effective IC50 value of 0.84 μM. Its presence also shifted the activation curve of Ih along the voltage axis to a more hyperpolarized potential, by 11 mV. PTER at a concentration greater than 10 μM could also suppress l-type Ca2+ and transient outward K+ currents in GH3 cells. With the addition of PTER, IK(Ca) amplitude was increased, with an EC50 value of 2.23 μM. This increase in IK(Ca) amplitude was attenuated by further addition of verruculogen, but not by tolbutamide or TRAM-39. Neither atropine nor nicotine, in the continued presence of PTER, modified the PTER-stimulated IK(Ca). PTER (10 μM) slightly suppressed the amplitude of l-type Ca2+ current and transient outward K+ current. The presence of PTER (3 μM) was also effective at increasing the open-state probability of large-conductance Ca2+-activated K+ (BKCa) channels identified in hippocampal mHippoE-14 neurons; however, its inability to alter single-channel conductance was detected. Our study highlights evidence to show that PTER has the propensity to perturb ionic currents (e.g., Ih and IK(Ca)), thereby influencing the functional activities of neurons, and neuroendocrine or endocrine cells.

Keywords

Ca2+-activated K+ current; Pterostilbene (trans-3,5-dimethoxy-4′-hydroxystilbene); hippocampal neuron; hyperpolarization-activated cation current; large-conductance Ca2+-activated K+ channel; pituitary cell.

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  • HY-101422
    99.89%, BKCa-Channel Blocker