Chemical Composition and <i>in vitro</i> Antioxidant Potential of <i>Tecoma stans</i> (L.) Juss. ex Kunth

Abstract

Tecoma stans (L.) Juss. ex Kunth (Bignoniaceae), commonly called yellow-bells, has found wide applications in traditional medicine. In the present study, the nutritional composition, phytochemicals and antioxidant potential of Tecoma stans plant parts was investigated. Carbohydrates ranked first among the macronutrients tailed by protein and ash. Seed displayed significant levels of protein, fat and ash, whereas leaf showed substantial amount of calcium and iron. Polyphenols and flavonoids were predominant in seed and leaf crude ethanolic extracts and fractions as compared to the flower sample. The crude ethanolic extracts and fractions were also evaluated for their scavenging action against DPPH, superoxide anion and hydroxyl radicals. Higher radical scavenging potential was observed in seed and leaf crude extracts and fractions. Among the fractions, n-butanol and ethyl acetate were significantly more efficient than the other fractions against the studied free radicals (p<0.05). These fractions also contained relatively higher levels of total polyphenols and flavonoids than the other fractions of the plant parts. All the crude ethanolic extracts and fractions of the samples showed a significant (p<0.05) dose-dependent radical scavenging action. Strong and positive correlations between phenolic compounds and free radical scavenging activities of Tecoma crude ethanolic extracts and fractions were observed. The obtained results exhibit that the studied plant parts are nutritionally valuable and excellent source of natural bioactive compounds.