Vegetable Oils in Skin Whitening - A Narrative Review

Plants are a source of a variety of compounds, such as vegetable oils, which are rich in fatty acids and possess skin-whitening properties. Considering the hyperpigmentation treatment challenges (lack of efficacy or aggressiveness), the constant search for new whitening substances is necessary. Given vegetable oils' potential and application in dermatological and cosmetic products, we reviewed the scientific literature on vegetable oils with skin depigmenting activity. It was observed that a variety of species (Adansonia digitata, Arctium lappa, Argania spinosa, Astrocaryum vulgare, Bertholletia excelsa, Borago officinalis, Camellia oleifera, Cucurbita moschata, Euterpe oleraceae, Hevea brasiliensis, Moringa oleifera, Nicotiana tabacum, Oenocarpus bataua, Oenothera biennis, Panax ginseng, Passiflora edulis, Pentaclethra macroloba, Perilla frutescens, Sapindus mukorossi, Taiwanese species Taichung selective No. 4 (TCS4) (Adlay bran), Torreya grandis) were evaluated in vitro regarding their skin whitening properties. All the studies demonstrated that the oils have skin whitening properties and that the oils' activity is related to their composition. The harvesting period, as well as the extraction method, impact on the oils' properties, hence in their activity. The use of vegetable oils can have advantages over an isolated compound as their components can have synergistic or adding effects. When conducting skin whitening experiments, it is recommended to employ multiple assays because vegetable oils can influence skin whitening through various mechanisms. Furthermore, more clinical trials should be encouraged, considering the potential of vegetable oils as skin-lightening ingredients. More innovative and effective formulations can be obtained using vegetable oils for skin whitening purposes.