The in vitro effect of gold complexes on bone resorption

Area of Science:

• Biochemistry
• Pharmacology
• Orthopedics

Background:

• Bone resorption and collagen synthesis are critical processes in skeletal health.
• Gold compounds have been investigated for their anti-inflammatory and immunomodulatory properties.
• Understanding the effects of gold complexes on bone metabolism is important for potential therapeutic applications.

Purpose of the Study:

• To evaluate the impact of three gold complexes--aurothioglucose, aurothiomalate, and auranofin--on bone resorption and collagen synthesis in mouse calvaria.
• To assess the influence of these gold compounds on cellular processes like DNA and protein synthesis.
• To investigate whether gold complexes affect lysosomal enzyme release, a marker of cellular activity.

Main Methods:

• Mouse calvaria were cultured in vitro without serum.
• Active bone resorption was measured by 45Ca release.
• Hydroxyproline synthesis, DNA synthesis, protein synthesis, and lysosomal enzyme release were quantified.

Main Results:

• All tested gold complexes exhibited some reduction in bone resorption.
• Auranofin was the most potent inhibitor of bone resorption within a narrow concentration range (10(-6) M).
• At 10(-6) M, auranofin significantly inhibited collagen synthesis but did not affect DNA or protein synthesis, and did not appear to inhibit lysosomal enzyme release.

Conclusions:

• Gold complexes, particularly auranofin, can inhibit bone resorption and collagen synthesis in mouse calvaria.
• Auranofin's mechanism of action does not appear to involve significant inhibition of lysosomal enzyme release.
• These findings suggest a potential role for specific gold compounds in modulating bone metabolism.