In Vitro and Ex Vivo Evaluation of Rifampicin Cytotoxicity in Human Skin Models

Area of Science:

• Pharmacology
• Toxicology
• Dermatology

Background:

• Drug safety assessment requires robust cytotoxicity testing.
• Evaluating drug toxicity in models closer to in vivo conditions enhances reliability.
• Rifampicin is a crucial bactericidal component of multidrug therapy for leprosy.

Purpose of the Study:

• To evaluate the cytotoxicity of rifampicin.
• To assess rifampicin toxicity in various skin cell models and ex vivo skin explants.
• To establish the ex vivo skin model as a viable alternative for drug toxicity assessment.

Main Methods:

• Cell viability assessed using MTT assay in primary keratinocytes, fibroblasts, and immortalized HaCaT/3T3 cells.
• Ex vivo skin explants evaluated with TTC assay for viability, H&E staining for tissue architecture, and TUNEL assay for apoptosis.
• Toxicity testing conducted over 24-96 hours at various rifampicin concentrations.

Main Results:

• Skin cell viability remained above 70% up to 50 μg/mL rifampicin, with increased sensitivity at 200 μg/mL by 72 hours.
• Ex vivo skin explants demonstrated high viability (>96%) at concentrations up to 200 μg/mL.
• Histological analysis confirmed preserved tissue architecture and absence of apoptosis in explants.

Conclusions:

• Rifampicin exhibits low cytotoxicity in skin cells and ex vivo skin models.
• The ex vivo skin model provides a reliable alternative to animal testing for drug toxicity evaluation.
• Comprehensive toxicity assessment necessitates diverse cell types and advanced models.