J. Cosmet. Sci., 70, 115–126 (May/June 2019) 115 Plant Small RNAs: A New Technology for Skin Care ELODIE OGER, LUDIVINE MUR, ALEXIA LEBLEU, LAURINE BERGERON, CATHERINE GONDRAN, and KARINE CUCUMEL, Ashland, Global Skin Research Center, Sophia- Antipolis, France (E.O., L.M., A.L., L.B., C.G., K.C.) Accepted for publication April 17, 2019. Synopsis This study was performed on an aqueous extract of baobab seedcake enriched in small ribonucleic acids (RNAs) for cosmetic use. The seedcake is a by-product, obtained from Baobab seeds belonging to the Adansonia digitata species. A particular patented extraction process, named plant small RNA (PSR) technology, has been developed to retain some specifi c nutrient compounds, including small RNAs. Small RNAs, such as microRNAs (miRNAs), play an essential role in gene regulation. The biological potential of this new patented PSR extract was studied in skin fi broblasts and in ex vivo skin. To demonstrate the effect relative to the presence of small RNAs, the same extract in which small RNAs were removed was also tested. After observing the effi cacy of PSR extract on collagen expression in ex vivo skin, different markers of senescence were investigated on fi broblasts aged by replicative senescence. The study of the expression of Drosha, an enzyme responsible for miRNA maturation, the expression of miRNA-19b, a biomarker of cellular aging, and the activity of senescence-associated β-galactosidase showed more effi cient activity of PSR extract, compared with small RNAs–free extract. Taken together, these studies demonstrate the potential of PSR extract for use in cosmetic end use applications. INTRODUCTION Baobab is a tree belonging to the Malvaceae family. Adansonia digitata is a species of bao- bab that grows in Africa’s sub-Saharan semi-arid and sub-humid regions. The largest specimen is 30-m tall and has a diameter of up to 11 m. Baobab, also known as the “tree of life,” is an integral part of the lives of indigenous people of African landscape, who use all parts of the baobab for food and in medicinal applications or for cosmetics (1). In particular, the baobab’s outstanding fruit is turned into a great variety of products. Pulp of the fruit is used in food. Its seeds are used to produce oil recognized for its benefi cial effect on skin. Several studies revealed that bao- bab’s Integral Antioxidant Capacity (IAC) was 10 times higher than orange pulp. The antioxidant power is due partly to the high content of its organic compounds such as ascorbic, citric, malic, and succinic acids. Furthermore, it has been described that all parts of the baobab (including the pulp, leaves, and seeds) not only have higher IACs than orange Address all correspondence to Ludivine Mur at lmur@ashland.com.
JOURNAL OF COSMETIC SCIENCE 116 pulp but also higher IACs than strawberry, bilberry, and kiwi pulp (2). The baobab fruit is a powerful anti-infl ammatory and antioxidant (3). Of 14 species of “wild edible fruits” evaluated, those from Adansonia digitata ranked second for highest phenolic and fl avonoid content, which are well-known for their antioxidant properties (4). The seeds are extracted from the baobab fruit by cracking the hard, outer capsule. The extracted seeds are then washed to remove the powder coating and then air-dried in the hot sun. These seeds can be stored for many months before pressing. Baobab oil is made by a cold pressing process. Baobab oil is an excellent skin moisturizer, which is quickly absorbed by the skin without clogging pores (5). It leaves the skin feeling soft and mois- turized. Indeed, thanks to its composition, its richness in omega 6–9 acids, vitamins, sterols, and minerals, organic baobab oil is ideal for use in cosmetics. Ashland has developed an extract obtained by valorizing oil by-product, the seedcake, which keeps the richness of cold pressing seeds. In particular, we developed an extraction process that allowed us to retain the healthy nutrients and compounds of interest such as phenolic compounds, sugars, proteins, and amino acids of the seeds, while also enriching our extract with small RNAs, named plant small RNA technology (PSR technology) (Figure 1). Figure 1. Flow chart of the PSR technology.
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