Metabolomics — the study of the chemical fingerprints that cellular processes leave behind — is well suited to analyzing an embarrassing problem — dandruff:
Dandruff is thought to be a complex inflammatory response to a common fungus on the scalp that disrupts the normal process of shedding skin cells. When people with a healthy scalp shed dead skin cells, enzymes digest the connections between the cells so the cells slough off individually, and invisibly. In some people, however, the immune system, for reasons that remain unknown, reacts to the fungus in a way that disrupts the typical enzyme process. This causes clusters of thousands of dead cells to be shed at the same time, resulting in visible flakes and itch. Dandruff affects millions of people in the U.S.
At Procter & Gamble, researchers hunted for molecules signaling inflammation of the outermost layer of scalp skin. The aim was to identify biological markers that indicate deeper changes going on within the skin tissue. Samples of skin cells were taken from the scalps of several hundred participants, some with dandruff and others with healthy skin. Researchers analyzed the chemicals that the cells from healthy scalps had produced and compared them to the dandruff sufferers. They eventually identified several markers of inflammation that differed between the groups. The markers can now be used to monitor participants in trials of new dandruff products to determine whether someone’s condition is improving, says Kevin Mills, a senior scientist in P&G’s beauty and grooming division and an author on the study that was published in January in the International Journal of Dermatology.
Another P&G dandruff study, published last month in Acta Derm Venereol, a Norwegian journal, used similar methods to look for chemical markers that were related to itching, a symptom that dandruff sufferers often complain about. They identified elevated histamine markers in dandruff sufferers, confirming the idea that histamine is involved in itch and could be targeted in future treatments. Dr. Mills says the findings could help advance research in skin conditions, including psoriasis and eczema.