The bioactive composition and biological activity of Indonesian Pelawan (Tristaniopsis merguensis Griff.) aqueous leaf extracts

• Traditional medicine has employed the leaves of Tristaniopsis merguensis. • Phytochemical analysis revealed that aqueous leaf extracts have a high value of total phenolic content, flavonoids, alkaloids, and saponin • Metabolome analysis using liquid chromatography-high resolution mass spectroscopy (LC-HRMS) identified 35 metabolite compounds in the extract. • T. merguensis aqueous leaf extract possesses anti-inflammatory and anti-diabetic and antioxidant properties. • T. merguensis aqueous leaf extract of is advised as a natural bioactive source with potential to prevent diabetes and function as an antioxidant. Pelawan (Tristaniopsis merguensis Griff) is an herbal remedy utilized by the indigenous population in Indonesia. This study aims to examine the phytochemical composition, in vitro anti-inflammatory effects, antioxidant capabilities, and antidiabetic properties of aqueous leaf extracts from Pelawan. The study revealed that the aqueous leaf extracts possess a significant total phenolic content of 264.556 mg GAE/g, as well as flavonoids at 44.667 mg QE/g, steroids measuring 41.107 mg/g, along with alkaloids and saponins. Metabolome analysis conducted through liquid chromatography-high resolution mass spectroscopy (LC-HRMS) identified 30 tentative compounds. The main compounds are provisionally identified as quinic acid, 1,6-bis-O-(3,4,5-trihydroxybenzoyl) hexopyranose, gallic acid, myricitrin, citric acid, caryophyllene oxide, NP-003141, myricetin 3-O-beta-D-galactopyranoside, myricetin, sedanolide, pyrrole-2-carboxylic acid, and sorbic acid. In both DPPH and H 2 O 2 assays, the aqueous leaf extracts demonstrate strong antioxidant activity that is dependent on dosage, with IC50 values of 14.04 µg/g and 55.51 µg/g, respectively. Additionally, it shows in vitro antidiabetic effects with an IC50 of 33±1.4 µg/g; however, it does not display antibacterial activity at concentrations up to 1,000 µg/g. The research demonstrates that aqueous leaf extracts of T. merguensis possess significant medicinal properties.