Dose-dependent in vitro cellular effects of peppermint, clove and garlic essential oils on caprine dermal fibroblasts

Objective Peppermint (PO), clove (CO), and garlic (GO) essential oils are widely recognized for their therapeutic properties in traditional medicine. However, their biological effects are highly concentration-dependent—higher concentrations may exert cytotoxic effects, while lower concentrations may reduce therapeutic efficacy. This study aimed to evaluate the in vitro dose-dependent effects of PO, CO, and GO on caprine dermal fibroblasts (cdFibroblast cells). Methods Cells were exposed to serial dilutions of each oil (1:2.5K, 1:5K, 1:10K, and 1:20K), and biological responses were analysed, including cell viability, cytotoxicity, colony-forming ability (CFU), and the expression of key genes associated with fibroblast identity, apoptosis, oxidative stress, and cellular stress response (vimentin, FSP-1, CuZnSOD, BAX, BCL-6, and HSP-72). Results Lower dilutions (1:2.5K and 1:5K) showed significant cytotoxicity, whereas moderate dilutions (1:10K and 1:20K) enhanced cell viability and CFU formation. PO and CO at 1:10K demonstrated optimal modulatory effects, while GO was more effective at 1:20K. Gene expression analysis further supported the concentration-dependent response, with upregulation of antioxidant and anti-apoptotic markers at non-toxic concentrations. Conclusion These findings suggest that these essential oils exert dose-dependent effects on caprine dermal fibroblasts, with optimized dilutions promoting cell viability and protective gene expression, supporting their potential use in tissue engineering.