The Key Phytochemistry of Rosemary Contributing to Hair Protection Against UV

The study analyzed extracts from rosemary (Salvia Rosmarinus) for their phytochemistry and tested their efficacy as antioxidants. Ten commercial extracts of rosemary were compared using LC–MS, and their antioxidant capacity was measured using ORAC and FRAP assays. The study found that the phytochemistry in each extract varied widely, with a total of 33 individual compounds identified. Two key compounds, rosmarinic acid and carnosic acid, were identified, with their presence correlating with antioxidant measures and UV protection on hair. Despite variations in the profile of phytochemistries in the ten rosemary extracts, all had antioxidant activity. The study concluded that polyphenols (e.g., rosmarinic acid, glycosides of selgin) and abietane diterpenes (e.g., carnosic acid) are the principal compounds in rosemary extracts that protect hair from UV damage.