Chinese licorice shows promise for reducing scalp itching and hair loss
medwireNews: A formula containing L-carnitine, creatine, and Glycyrrhiza inflata, otherwise known as Chinese licorice, shows great potential for stimulating hair roots, supporting growth of hair, and reducing hair thinning, say researchers.
Another combination, also containing Chinese licorice, as well as urea and polidocanol, significantly reduced scalp dryness and inflammation, report Jack Rippke (Beiersdorf Ag, Research and Development, Hamburg, Germany) and colleagues at the European Academy of Dermatology and Venereology annual congress in Prague, Czech Republic.
The first of the two studies, both of which were presented as E-posters, involved in vitro and in vivo testing of the first formula both on cultured human hair follicle cells and on the scalps of 93 women (mean age 44.8 years; Ludwig scale ≤1) and 60 men (mean age 24.7 years; Hamilton score ≤5).
The in vitro experiments showed that L-carnitine increased beta oxidation of outer root sheath cells (ORS), L-carnitine and creatine raised the number of anagen follicles, and lichochalcone A (a constituent of Chinese licorice) significantly reduced inflammatory activity.
The in vivo study involved the participants applying the formula to half their head for 3 months and a placebo formula to the other side. At 3 months, hair diameters were significantly improved on the formula-treated scalp sections compared with the placebo-treated sections. Daily hair growth was also significantly improved using the formula compared with placebo.
In the second study, 30 individuals with dry and itchy scalp, aged 26 to 73 years, were enrolled. They had the second Chinese licorice-based formula applied to half their scalps after hair washing three times a week for 4 weeks by trained experts. The other half of their scalps was left untreated following hair washing. The participants agreed to use no other hair products during the experiment.
Outcomes were assessed by corneometry and enzyme-linked immunosorbent assay (ELISA). Rippke and team found that scalp hydration was significantly higher on the treated than the non-treated scalp side, with approximate corneometry readings of 46 versus 31 µS at 4 weeks.
Results from ELISA analysis of scalp wash-ups from the treated versus the non-treated sides also demonstrated a significant 15‑20% reduction from baseline to 2 weeks in levels of the inflammatory cytokines interleukin (IL)-1 receptor antagonist/IL-1β and IL-8.
"The scalp tonic excellently alleviated irritated scalp symptoms like scalp dryness, itching and microinflammation," conclude Rippke and colleagues. "This is the result of the contents of the tonic like the humectant ingredient urea, the skin calming substance polidocanol and the anti-inflammatory component licochalcone A of the G. inflata root extract."
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By Helen Albert, Senior medwireNews Writer