HAIR CARE FORMULATIONS CONTAINING CARNITINE DERIVATIVES ACTIVATE CELLULAR ENERGY METABOLISM AND BOOST THE ATP CONTENT IN HUMAN HAIR FOLLICLES
EHRS - Zurich 2005
Giesen M, Hoting E, Schulze zur Wiesche E, Petersohn D
Henkel KGaA, Düsseldorf, Germany
Active energy metabolism is an essential prerequisite for the growth of strong and healthy hair. Not only the differentiation and proliferation of hair follicle keratinocytes, which form the visible hair shafts, depend on energy consuming processes, but also production of growth factors, cytokines etc. by neighbouring cells (e.g. dermal papilla cells) need to be supplied with chemically bound energy.
In biological systems ATP acts as the universal energy currency. Thus, determination of ATP levels in living cells is suitable to assess the cellular metabolic activity and energy. Using cultivated hair follicle cells within screening systems we identified bio-actives that significantly increased cellular ATP contents, albeit to varying extents.
The most potent, carnitine tartrate, was used to enrich hair care formulations, which were then further investigated in a placebo controlled panel study. In a left/right comparison healthy male volunteers applied two hair tonic formulations twice daily for four days. The verum formulation contained 2% carnitine tartrate encapsulated in liposomes, whereas the placebo contained empty liposomes. Throughout the test period ATP content within plucked hair follicles was determined twice daily using a commercially available test kit.
Statistical evaluation of baseline adjusted values demonstrated a significant increase in ATP equivalents in human hair roots treated with carnitine tartrate. These effects were absent in the placebo group, thus underlining the stimulating activity of carnitine tartrate. The outstanding bio-activity of carnitine tartrate was furthermore demonstrated in a second study, assessing the effects after a single application of a shampoo formulation supplemented with carnitine tartrate. Again, ATP levels in plucked human hair follicles were significantly increased.
We conclude that carnitine tartrate is an ideal ingredient for hair care formulations, providing energy for the optimal environment to produce strong and healthy hair.