Microarray analysis of altered gene expression in diallyl trisulfide-treated HepG2 cells.

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• Diallyl trisulfide (DT) is a natural compound found in garlic with known lipid-lowering properties.
• The precise molecular mechanisms underlying DT's lipid-lowering effects remain largely unelucidated.
• Understanding these mechanisms is crucial for exploring DT's therapeutic potential.

Purpose of the Study:

• To investigate the molecular mechanisms of lipid-lowering effects of Diallyl trisulfide (DT) in HepG2 cells.
• To identify genes differentially regulated by DT treatment using microarray technology.
• To determine optimal non-cytotoxic concentrations of DT for cellular lipid reduction.

Main Methods:

• HepG2 cells were treated with varying concentrations of Diallyl trisulfide (DT) for 24 hours.
• Oligonucleotide microarrays were employed to analyze gene expression profiles.
• Quantitative real-time PCR (RT-PCR) was used to validate key gene expression changes.

Main Results:

• DT concentrations between 20-50 microM effectively reduced cellular triglyceride and cholesterol levels without significant cytotoxicity.
• Microarray analysis revealed differential gene expression patterns following DT treatment.
• Key findings include up-regulation of peroxisome proliferator activated receptor alpha (PPAR-alpha) and hepatocyte nuclear factor 4alpha (HNF-4alpha) mRNA, and down-regulation of CYP7A1 mRNA.

Conclusions:

• Diallyl trisulfide (DT) demonstrates significant lipid-lowering effects in HepG2 cells at concentrations of 20-50 microM.
• The lipid-lowering action of DT appears to be mediated, at least in part, by the regulation of PPAR-alpha dependent pathways.
• DT's effects on PPAR-alpha, HNF-4alpha, and CYP7A1 suggest a role in modulating lipid metabolism.