Can a Tiny Larva Help Us Solve Dandruff?
Maritza Torres, Juliana Diaz-Ortiz, Michael G. Davis, James R. Schwartz, Adriana Marcela Celis Ramírez
Galleria mellonella as a superficial model for Malassezia globosa and its treatment
BACKGROUND
Malassezia globosa is a yeast species associated with dermatological disorders like dandruff, a chronic scalp condition marked by flaking and itching. Treatments often include commercial shampoos containing antifungals such as zinc pyrithione (ZPT) or piroctone olamine (PO). The effectiveness of these formulations has been evaluated for decades for dandruff symptom relief; non-mammalian, in vivo methods exist to test formulations of these actives.
OBJECTIVE
To evaluate in vivo the effectiveness of two commercial antifungal shampoos (shampoo with 1% ZPT and 1.6% zinc Carbonate and shampoo with 0.5% PO) against M. globosa using Galleria mellonella larvae.
METHOD
G. mellonella larvae were inoculated with M. globosa on an abraded cuticular surface. The abrasion was made based on a previous study in which sandpaper was used for this purpose. Then, integument cell viability, histological changes, and fungal burden were evaluated. The shampoo formulations were applied to the larvae, and their effect on fungal burden and tissue damage was assessed.
RESULTS
Larvae inoculated with M. globosa showed higher lesion melanization and tissue damage. The M. globosa population increased over time. Both shampoo formulations (ZPT and PO) significantly reduced M. globosa burden and tissue damage. The cell viability of larvae treated with antifungal shampoos was higher than those treated with a blank shampoo.
CONCLUSION
G. mellonella larvae are a valuable model for studying Malassezia-host interaction during superficial infection and evaluating antifungal effectiveness. Shampoos with ZPT and PO showed a positive effect on inoculated larvae, reducing fungal burden and tissue damage. This study shows that commercial anti-dandruff shampoos can help to control and maintain the yeast population, thus reducing the symptoms of dandruff.
Click here to read the full study >
CONFLICTS OF INTEREST STATEMENT
The CeMoP research group has received funding from Procter and Gamble to finance this study. M.G.D. and J.R.S. are employees of Procter and Gamble.
Funding information: External funding from Procter and Gamble was received for this study.