A comparative study of the safety and efficacy of 75% mulberry (Morus alba) extract oil versus placebo as a topical treatment for melasma: a randomized, single-blind, placebo-controlled trial.

BACKGROUND

Melasma is an aesthetically undesirable skin condition which remains difficult to treat. Mulberry is a whitening agent with antioxidant properties.

OBJECTIVE

To evaluate the safety and efficacy of 75% mulberry extract oil as a treatment for melasma versus placebo.

PATIENTS AND METHODS

50 patients were recruited and randomly assigned into two groups, with 25 treated with 75% mulberry extract oil and the other 25 treated with placebo. All patients had a negative repeat open application test (ROAT) to both mulberry extract and placebo. Patients were followed up regularly at four-week intervals for a total of eight weeks. The severity of the melasma was assessed using the melasma area and severity score (MASI), Mexameter reading, melasma quality of life score (MelasQOL) and any adverse events noted.

RESULTS

The mean MASI score significantly improved from 4.076 (± 0.24) at baseline to 2.884 (± 0.25) at week 8 for the 75% mulberry extract oil group while the placebo group showed an improvement of a lesser magnitude. Mexameter readings for the mulberry group showed a significant drop from 355.56 (± 59.51) at baseline to 312.52 (± 57.03) at week 8 compared to the placebo group, whose Mexameter readings deteriorated from 368.24 (± 46.62) at baseline to 372.12 (± 44.47) at week 8. The MelasQOL score also improved tremendously for the 75% mulberry extract oil group, falling from 58.84 (SD: ± 3.18) at baseline to 44.16 (SD: ± 4.29) at week 8, unlike the placebo group that showed a less dramatic improvement from 57.44 (SD: ± 4.66) at baseline to 54.28 (SD: ± 4.79) at week 8. With regards to the adverse events, only mild itching was reported in four patients from the 75% mulberry extract oil group while there were 12 cases of either itching or erythema reported from the placebo group.