Brown spots: Moringa oil for skin tone unification?

Derived from the seeds of the Moringa oleifera, a tree native to India, often referred to as the "tree of life" or "miracle tree", moringa oil is used in the composition of numerous cosmetic products. It is primarily known for its moisturising and emollient properties, but this ingredient also has antioxidant, soothing and healing effects. It is also possible that moringa oil may help to prevent and reduce the appearance of pigmentation spots, which correspond to an abnormal accumulation of melanin in the skin. Brown spots often result from repeated and prolonged sun exposure throughout life. Depending on skin sensitivity, they usually appear between the ages of 45 and 50.

It is plausible that moringa oil may help prevent brown spots. Indeed, it has antioxidant activity due to its richness in antioxidants, particularly vitamin E. Moringa oil can thus protect the skin from oxidative stress, caused among other things by the sun's UV rays. Thanks to its chemical structure, vitamin E neutralises free radicals before they attack cellular constituents and disrupt the process of melanogenesis. Epidermal melanocytes are indeed very sensitive to oxidative stress. More specifically, the free hydroxyl function carried by the aromatic cycle of vitamin E reacts with free radicals and provides them with the missing electron, which allows them to stabilise and cancel their reactivity.

Furthermore, an in vitro study has shown that moringa oil possesses anti-tyrosinase activity, likely due to its richness in quercetin. As a reminder, tyrosinase is an enzyme involved in the biosynthesis of melanin, catalysing the oxidation of tyrosine into melanin. During the study, the median inhibitory concentration (IC50) of moringa oil was compared to that of kojic acid, a molecule known for its depigmenting effect. The IC50 is a measure commonly used in pharmacological and cosmetic studies to evaluate the effectiveness of a compound in inhibiting a biological function. It represents the concentration of a molecule that is required for 50% inhibition in vitro. The results obtained during the study are presented in the table below. By blocking tyrosinase, moringa oil could be beneficial for reducing sensitivity to hyperpigmentation.

The depigmenting properties of moringa oil have also been demonstrated ex vivo on a reconstructed human epidermis. Scientists observed that the application of 8 µL of moringa oil for 6 days resulted in a 17.63% reduction in melanin production. Using 28 µL, the reduction was 21.31%. In comparison, the application of 40 µL of a 1 g/L kojic acid solution (reference concentration) led to a 24.58% decrease in melanin synthesis. Therefore, the anti-depigmenting properties of moringa oil could be almost comparable to those of kojic acid without presenting the same risks. The moringa oil is indeed a well-tolerated vegetable oil, while kojic acid is a suspected endocrine disruptor and a potential irritant.

Moringa oil could be an intriguing natural alternative for evening out skin tone. In the future, it would be interesting for clinical trials to highlight this property.

• JIN X. & al. Moringa oleifera stem extract safeguards skin keratinocytes from oxidative stress damage through the augmentation of antioxidant defence mechanisms and activation of PPARα. Biomedicine & Pharmacotherapy (2018).

• LTEIF R. & al. Skin lightening effect of natural extracts derived from Senegal's botanical biodiversity. International Journal of Dermatology (2019).

• JUNIOR D. & al. Moringa oleifera seed oil: A review. Journal of Research in Agriculture and Animal Science (2021).

• BASO F. & al. Formulation of Skin Brightening Cream and Tyrosinase Inhibition Assay of Moringa Leaf Extract. International Journal of Pharmaceutical and Bio-Medical Science (2022).