Curcumin Inhibits ACTH- and Angiotensin II-Stimulated Cortisol Secretion and Cav3.2 Current

Adrenocorticotropic hormone and angiotensin II stimulate cortisol secretion from bovine adrenal zona fasciculata cells by the activation of adenylate cyclase and phospholipase C-coupled receptors. Curcumin (1− 20 μM), a compound found in the spice turmeric, inhibited cortisol secretion stimulated by ACTH, AngII, and 8CPT-cAMP. Curcumin also suppressed ACTH-stimulated increases in mRNAs coding for steroid acute regulatory protein and CYP11a1 steroid hydroxylase. In whole cell patch clamp recordings from AZF cells, curcumin at slightly higher concentrations also inhibited Cav3.2 current. These results identify curcumin as an effective inhibitor of ACTH- and AngII-stimulated cortisol secretion. The inhibition of Cav3.2 current by curcumin may contribute to its suppression of secretion.