Abstract
Bougainvillea spectabilis Willd. (B. spectabilis), A vibrant ornamental plant native to South America has recently garnered scientific interest due to its diverse phytochemical composition and potential biomedical applications. This study aimed to evaluate the chemical constituents, antioxidant properties, and in vitro cytotoxic effects of ethanolic and aqueous extracts derived from the flowers of B. spectabilis cultivated in Northern Cyprus. Extracts were prepared using Soxhlet extraction, followed by characterization through Fourier transform infrared spectroscopy (FTIR), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopies, revealing the presence of various flavonoids, phenolics, and other bioactive compounds. Antioxidant activity was confirmed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays, correlating positively with total phenolic and flavonoid contents. Cytotoxicity was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays on human umbilical vein endothelial cells (HUVECs) at 24, 48, and 72-h intervals. Both extracts exhibited no cytotoxic effects at tested concentrations, maintaining cell viability above 75%. Notably, a pronounced proliferative response was observed, particularly at 48 and 72 h, with ethanolic extract achieving a peak viability of 153%, to reflect metabolic activity more cautiously. These findings suggest that B. spectabilis flower extracts are not only biocompatible but may also possess pro-proliferative properties, underscoring their promise in regenerative medicine and endothelial cell research.