Phytochemical Investigation of an Ostrya carpinifolia L. Extract: an Effective Anti‐Pollution Cosmetic Active Ingredient.

Abstract

Ostrya carpinifolia L., a member of the Betulaceae family, is a tree endemic to the Mediterranean basin that is well known for the hardness of its wood. In this study, we assess the anti‐pollution activities of a hydroalcoholic extract of O. carpinifolia twigs using several judiciously selected in vitro cosmetic bioassays. The extract's capacity to counteract excessive production of reactive oxygen species following a cutaneous exposure to atmospheric pollution was evaluated using a combination of several antioxidant assays: DPPH, FRAP and β‐carotene bleaching assays. These antioxidant assays were complemented by anti‐elastase, anti‐collagenase, anti‐hyaluronidase and anti‐lipoxygenase assays to evaluate the capacity of the extract to preserve the integrity of the skin. The hydroalcoholic extract of O. carpinifolia demonstrates intriguing biological antioxidant activities, with approximately 50% inhibition observed in DPPH and β‐carotene assays. Furthermore, its anti‐lipoxygenase, anti‐hyaluronidase, and anti‐collagenase activities are noteworthy, exceeding 50% inhibition. The two major compounds of O. carpinifolia ethanolic extract were isolated and identified as myricitrin (1) and quercitrin (2). Myricitrin and quercitrin exhibit antioxidant and anti‐hyaluronidase properties; we explored the correlation of these properties with the activity of the crude hydroalcoholic extract. Notably, these compounds have not been previously described in the Ostrya genus.