Synthesis and anti-inflammatory effect of chalcones

Area of Science:

• Medicinal Chemistry
• Pharmacology
• Immunology

Background:

• Inflammatory disorders involve mast cell and neutrophil degranulation.
• Microglial cells and macrophages are implicated in central nervous system (CNS) inflammation.
• Targeting these pathways could yield effective anti-inflammatory agents.

Purpose of the Study:

• Synthesize novel chalcone derivatives, specifically 2'-hydroxy- and 2',5'-dihydroxychalcones.
• Evaluate their in-vitro inhibitory effects on mast cells, neutrophils, microglial cells, and macrophages.
• Identify potent anti-inflammatory compounds for potential therapeutic use.

Main Methods:

• Chalcones synthesized via Claisen-Schmidt condensation.
• Alkoxychalcones prepared from hydroxychalcones and alkyl iodide.
• Dihydroxychalcones obtained through catalytic hydrogenation.
• Inhibitory effects assessed on beta-glucuronidase/lysozyme release from neutrophils and nitric oxide (NO) production from microglial cells.

Main Results:

• Most hydroxychalcones potently inhibited neutrophil degranulation (beta-glucuronidase and lysozyme release).
• Compound 1 showed the highest potency in inhibiting neutrophil degranulation (IC50 values of 1.6±0.2 µM and 1.4±0.2 µM).
• Most 2',5'-dialkoxychalcones potently inhibited nitric oxide (NO) formation in microglial cells (Compound 11: IC50=0.7±0.06 µM).

Conclusions:

• Chalcone derivatives exhibit significant anti-inflammatory activity.
• Hydroxychalcones primarily act by inhibiting mast cell and neutrophil degranulation.
• Dialkoxychalcones (10-12) likely exert anti-inflammatory effects by suppressing NO formation in microglial cells, suggesting distinct mechanisms of action.