The findings from these innovative studies, which investigated the topical application of botanical compounds with and without tetrahydropalmatine (THP), underscore a promising avenue for enhancing the topical delivery efficiency of drugs and nutrients.
The above results should be regarded as preliminary, especially in view of challenges that the current experimental methods provide
One of the most important challenges is consistency of the biological material. Use of eggshell membrane as a skin model requires standardization of eggshell membrane thickness for more reproducible results. The skin graft model, on the other hand, needs methods to prevent biodegradation of isolated skin and changing conditions of permeation
THP, based on clinical experimentation with its parent compound piperine, holds to be promising as a versatile adjuvant for a broad range of nutrient and drug delivery through the skin.
Proposed mechanisms of action
At present, there is insufficient experimental data to postulate a bio enhancing mechanism of THP
THP may operate by increasing either or two of the events: 1. Membrane fluidity, and 2.The affinity of nutrient/drug to the cell membrane
It should be also considered that THP which is a lipophilic compound may increase the solubilization of the intracellular lipid moiety in the skin, making it more permeable to the applied nutrient/drug
Interestingly, THP may per se be a skin nutrient theoretically improving skin health and further its ability to receive and selectively absorb various nutrients. This hypothesis is based on the experimental data with parent compound piperine which was shown to be involved in the regulation of several neuropeptides
