These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Differential suppression of delayed-rectifier and inwardly rectifier K+ currents by a group of ent-kaurane-type diterpenoids from Croton tonkinensis, in microglial cells.
    Author: Hsiao HT, Lee YC, Liu YC, Kuo PC, Wu SN.
    Journal: Eur J Pharmacol; 2019 Aug 05; 856():172414. PubMed ID: 31129155.
    Abstract:
    Croton is an extensive flowering plant genus in the spurge family, Euphorbiaceae. Three croton compounds with the common ent-kaurane skeleton were purified from Croton tonkinensis. By using patch-clamp recording technique, we thoroughly examined the effect of a group of croton compounds, croton-01 (ent-18-acetoxy-7α-hydroxykaur-16-en-15-one), croton-02 (ent-7α,14β-dihydroxykaur-16-en-15-one), and croton-03 (ent-1β-acetoxy-7α,14β-dihydroxykaur-16-en-15-one), on the membrane current in SM826 and BV2 microglial cells. Although neither voltage-gated Na+ nor Ca2+ currents were present in these cells, both delayed-rectifier K+ outward (IK(DR)) and inwardly rectifying K+ currents (IK(IR)) were readily detected. Croton-03 differentially caused inhibition of IK(DR) or IK(IR) in a concentration-dependent manner. According to a minimal scheme, the shortening of the time constant in either the IK(DR)-related block or IK(IR) caused by different concentrations of croton-03 was quantitatively estimated with a dissociation constant of 6.45 and 29.5 μM, respectively. In SM826 cells differentiated with β-amyloid, inhibitory action on these K+ currents remained unaltered. In ultraviolet C-irradiated cells, the magnitude of IK(IR) was still decreased by addition of croton-03. Therefore, our study suggests that these ent-kaurane diterpenoids ought to somehow act on the cellular mechanisms by which they influence the functional activities of microglial cells.
    [Abstract] [Full Text] [Related] [New Search]