Novel and selective calcitonin-inducing agents.

Area of Science:

• Pharmacology
• Endocrinology
• Bone Biology

Background:

• Osteoporosis is a significant health concern, particularly after menopause.
• Current treatments for bone loss have limitations.
• Calcitonin (CT) plays a role in bone metabolism.

Purpose of the Study:

• To identify novel compounds that can induce calcitonin (CT) production.
• To evaluate the potential of these compounds as a new therapeutic strategy for osteoporosis.

Main Methods:

• Synthesis and screening of xanthine sulfonamides.
• Utilized CT-luciferase reporter gene assay (CT-luci) to measure CT transcription.
• Employed CT secretion/RIA assay (CTS) to assess CT production and release.
• Evaluated phosphodiesterase type IV (PDE4) inhibitory activity.
• Assessed bone protection in ovariectomized (OVX) rats using quantitative computed tomography (QCT).

Main Results:

• Certain di-n-butylxanthine sulfonamides upregulated CT transcription and increased CT production/release.
• Compound 9 demonstrated a 2.1-fold transcription activation ratio and a 3.6-fold increase in CT secretion.
• Compound 9 showed significant trabecular bone protection (47-50%) in OVX rats, with minimal PDE4 inhibition (IC50 = 4.1 microM).
• Efficacy compared favorably to salmon CT in preclinical models.

Conclusions:

• Xanthine sulfonamides represent a promising class of CT inducers.
• These compounds offer a potential new therapeutic avenue for treating postmenopausal bone loss and osteoporosis.
• Compound 9 warrants further investigation as a potential drug candidate.