South African Journal Of Botany, cilt.139, ss.42-49, 2021 (SCI-Expanded)
Limonium delicatulum is a halophyte growing in extreme conditions and therefore constituted a possible
source of bioactive compounds. In the present study, total phenolic, flavonoids, and condensed tannins were
quantified. DPPH, ABTS, Galvinoxyl radical (GOR), CUPRAC, reducing power, O-phenanthroline, silver nanoparticle, and b-carotene bleaching assays were used to evaluate the antioxidant capacity. The inhibitory
effect on tyrosinase activity and denaturation of BSA were also investigated. The results showed that extraction solvent, as well as plant organ, significantly influenced the contents of phenolic compounds. Methanolic
roots extract contained the highest phenolic content with a value of 772.52 § 5.12 mg GAE/mg consisting
mainly of condensed tannins (678.87 § 0.11 mg EC/mg of extract), while methanolic leaves extract recorded
the highest content of flavonoids (212.77 § 1.19 mg QE/mg extract). Methanolic extracts with high phenolic
contents exerted the strongest antioxidant activity compared to the aqueous extracts. Moreover, methanolic
roots extract exhibited high tyrosinase inhibition ability with an IC50 of 9.87 § 0.15 mg/ml better than that of
methanolic leaves extract and kojic acid (24.77 § 0.5 and 25.23 § 0.21 mg/ml, respectively), The studied
extracts also inhibited the denaturation of BSA in dose-dependent manner. Methanol extracts presented
higher inhibition percentages than aqueous extracts and similar to that obtained with diclofenac sodium. L.
delicatulum can be considered as a promising source of therapeutic bioactive compounds.