Phytochemical Profile, Antioxidant Potential, and Hemolytic Safety of Tecoma stans (L.) Kunth Leaf and Flower Extracts Using Different Solvents

Abstract

Tecoma stans, a tropical shrub, is traditionally used to treat diabetes, inflammation, infections, and digestive issues. While its antioxidant and antimicrobial effects are recognized, limited data exist on the hemolytic safety of its extracts. This study examined the phytochemical composition, antioxidant potential, and hemolytic safety of T. stans leaf and flower extracts prepared with three different solvents: dichloromethane, ethyl acetate, and 70% ethanol. Extraction yields were highest with 70% ethanol, reaching 18.64% for flowers and 6.6% for leaves extracts. Qualitative screening identified nine of ten targeted classes, including alkaloids, phenolics, flavonoids, terpenoids, and glycosides, while anthraquinones were absent in all extracts. Ethanolic extracts demonstrated the most diverse phytochemical profiles. Quantitative analysis confirmed that the ethanol leaf extract contained the highest total phenolic content (261.788 ± 6.229 mg GAE/g) and total flavonoid content (794.641 ± 259.249 mg QE/100 g). Antioxidant activity, assessed via ABTS and DPPH radical scavenging assays, showed the strongest activity in ethanol extracts. Specifically, in the ABTS assay, the ethanol leaf extract exhibited an IC₅₀ of 4.524 ± 0.122 µg/mL, surpassing the ascorbic acid standard. Similarly, the ethanol leaf extract exhibited the highest DPPH radical scavenging activity (IC₅₀ = 12.693 ± 0.207 µg/mL). Hemolysis and anti-hemolysis tests indicated that all extracts, across concentrations from 0 to 512 µg/mL, were non-hemolytic and conferred protection against red blood cell lysis. These findings suggest that T. stans, particularly its ethanol extracts, are abundant in bioactive compounds, exhibit significant antioxidant effects, and excellent hemocompatibility, supporting their potential for therapeutic or nutraceutical applications.