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Updated: Aug 16, 2026

Primary Culture of Rat Adrenocortical Cells and Assays of Steroidogenic Functions
Published on: March 12, 2019
Signaling pathways of magnolol-induced adrenal steroidogensis
Yung-Chia Chen1, Ming-Fong Chang, Ying Chen
1Department of Anatomy and Cell Biology, College of Medicine, National Taiwan University, 1-1 Jen-Ai Road, Taipei, Taiwan.
Abstract:
This study focused on identifying the signalling mediating the effect of magnolol on corticosterone production. Magnolol-induced corticosterone production was completely inhibited by mitogen-activated protein kinase kinase (MEK)-inhibitor PD98059, tyrosine kinase (TK)-inhibitor genistein or Janus tyrosine kinase 2 (JAK2)-inhibitor AG490, suggesting that extracellular signal-regulated kinase (ERK) and JAK2 are both involved in this signaling cascade. Further, magnolol induced the transient phosphorylation of MEK, ERK, cAMP response-element binding protein (CREB) and the expression of 32 and 30 kDa steroidogenic acute regulatory protein (StAR) in a time-dependent manner. Inhibition of TK or JAK2 activities blocked magnolol-induced phosphorylation of MEK and ERK, again supporting the upstream role of JAK2. The activation of JAK2 or MEK apparently mediated the magnolol-induced phosphorylation of CREB and the upregulation of StAR. These findings demonstrate a novel pathway for magnolol to induce the expression of StAR, which regulates the rate-limiting step in sterodiogenesis.
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