Comparative phytochemical analysis of syzygium formosum (Wall.) masam leaf and its biological activities

Syzygium formosum (SF) leaves have long been used in traditional medicine for the treatment of skin-related diseases such as atopic dermatitis and psoriasis. To understand the underpinning pharmacological mechanism of skin relief functionality, the quantitative profile of phytochemicals in the leaf extract has been performed. Twenty phytochemical components including eight flavonoids, three phenolic acids, and nine triterpenoids were identified and quantitatively analyzed from the SF leaves. The dominant flavonoids of the SF leaves were found to be catechin and myricetin-3-O-rhamnoside. Gallic acid was the most abundant phenolic acid. Among triterpenoids, asiatic acid, corosolic acid, and betulinic acid exhibited a high concentration ranging 2.78–8.59, 3.19–3.91, and 3.58–6.14 mg/g dry leaf, respectively. The total triterpenoid contents were 14.18–19.00 mg/g dry leaf which were 3-fold higher than those in the Indonesian Centella asiatica leaves. In human keratinocytes assay, industrial scale extract of SF significantly reduced expressions of proinflammatory cytokines and cyclooxygenase-2. Furthermore, that SF extract exhibited very strong antibacterial activity on Staphylococcus aureus and Cutibacterium acnes that possibly induce serious skin problems. Our results proved that S. formosum leaf extract with high content of biologically active compounds could be a superior bioactive ingredient in cosmetic and pharmaceutical products. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.