Peppermint (Mentha piperita, of the Labiatae or Lamiaceae family), a native herb of Mediterranean Europe that is cultivated in many parts of the world.
Rich in menthol, menthone, and menthyl acetate.
COOLING SENSATION
Topical preparations of peppermint oil have been used to calm pruritus and relieve irritation and inflammation. Menthol’s characteristic cooling sensation is due to the activation of the sensory neurons generally termed transient receptor potential (TRP) channel, in particular transient receptor potential melastatin family member 8 (TRPM8) and transient receptor potential subfamily A, member 1 (TRPA1).
Menthol acts upon TRPM8 receptors by rapidly increasing intracellular calcium and mobilizing calcium flux through the channels to induce cold response signals at the application site.
ANALGESIC
Menthol has an analgesic effect by blocking the voltage-gated Na+ channel. Consequently, it reduces the pain sensation.
ANTIBACTERIAL
Menthol has antibacterial properties against Gram-positive and Gram-negative bacteria including Staphylococcus aureus and Escherichia coli by inhibiting the growth of their microbial strains.
As a result of their lipophilic character, it can cross the cell membrane, penetrating the interior of the cell and interacting with intracellular sites critical for antibacterial activity. Moreover, it causes perturbation of the lipid fraction of bacterial plasma membranes.
This results in membrane expansion, increased membrane fluidity and permeability, disturbance of membrane-embedded proteins, inhibition of respiration, and alteration of ion transport processes.
Peppermint Essential Oil is safe to be used in cosmetic practice based on the concentration specified in the safety assessment when formulated to be non-sensitizing.
https://online.personalcarecouncil.org/ctfa-static/online/lists/cir-pdfs/FR741.pdf
https://pubmed.ncbi.nlm.nih.gov/21144345/
https://pubmed.ncbi.nlm.nih.gov/23061635/
https://pubmed.ncbi.nlm.nih.gov/29524352/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4103722/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5513973/