Phytochemical Screening, Antioxidant Potential, and LC-ESI-MS Profiling of Ephedra alata and Ephedra altissima Seeds Naturally Growing in Tunisia

Abstract

Most Ephedra species are adapted to arid and desert conditions and are widely used in folk medicine to treat several disorders. The design of the current study was to determine the functional properties of seeds of two Ephedra species (E. alata and E. altissima) naturally growing in Tunisian arid zones by evaluating their mineral contents and bioactive compounds. The flame atomic absorption spectrometry revealed that seeds contained remarkable amounts of sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), zinc (Zn), and iron (Fe). The colorimetric investigation revealed high total polyphenol, flavonoid, and condensed tannin contents. Furthermore, by utilizing high-performance liquid chromatography-electrospray ionization-mass spectrometry method (HPLC-ESI/MS), a total of 11 phenolics were identified and quantified including 7 flavonoid compounds and 4 phenolic acids that were mostly predominated by gallic acid and quercetrin. Results so far have been very encouraging and proved that Ephedra seeds are a valuable source of natural bioactive compounds and minerals which could potentially be used for industrial and pharmaceutical purposes.

Keywords: Bioactive compounds; Gallic acid; HPLC-ESI/MS; Minerals; Phenolics; Quercetrin.

Fig. 1

Ephedra alata (a) and Ephedra altissima (b) seeds

Fig. 2

Total polyphenol, total flavonoid, and condensed tannin contents in E. alata and E. altissima seeds. The different lowercase letters (a, b) indicate significant (p < 0.05) differences between E. alata and E. altissima seeds for polyphenol, flavonoid, and condensed tannin contents. TPC, total polyphenol content; TFC, total flavonoid content; CTC, condensed tannin content. Data expressed as means ± SD (n = 3)

Fig. 3

Antioxidant potential in the seeds of E. alata and E. altissima. The different lowercase letters (a, b) indicate significant (p < 0.05) differences between E. alata and E. altissima seeds for TAC (mg GAE/g dw), RPA (EC₅₀) assays, DPPH (IC₅₀), and ABTS (IC₅₀). TAC, total antioxidant capacity; RPA, reducing power assay. Data expressed as means ± SD (n = 3)