Phytochemical Characterization, Antioxidant and Antimicrobial Activities of Calicotome villosa Link from Morocco

In this research, we evaluated the antioxidant and antimicrobial activities of hydroalcoholic and aqueous extracts from four distinct parts of Calicotome villosa from Morocco (flowers, leaves, stems and roots). Quantification of total polyphenols by the Folin-Ciocalteu method and flavonoids by the aluminum trichloride method revealed variable concentrations. The hydroalcoholic leaf extracts showed the highest concentrations of total polyphenols (35.21 mg GAE/g extract) and flavonoids (58.67 mg QE/g extract), while the hydroalcoholic root extract showed the highest content of condensed tannins, determined by the vanillin method. The antioxidant activity of extracts was assessed using three complementary methods; DPPH free radical scavenging, iron reduction (FRAP) and total antioxidant capacity (TAC). The IC₅₀ obtained for the DPPH test ranged from 0.05 mg/mL (for hydroalcoholic leaf extracts) to 0.41 mg/mL (for aqueous root extracts), showing a lower free radical scavenging activity than ascorbic acid (0.001 mg/mL). According to the FRAP method, the leaf fraction showed a higher reducing power than other parts of the plant, although slightly lower than that of ascorbic acid. Compounds in root and leaf extracts have a significant total antioxidant capacity, followed by stems and flowers, in the order of 0.34 ± 0.07 (hydroalcoholic roots) and 0.30 ± 0.06 (hydroalcoholic leaves) mg EAA/g extract. As regards antimicrobial activity, hydroalcoholic extracts showed significant inhibition against several multi-resistant bacterial strains, such as Staphylococcus aureus, Dickey asolani, Pectobacterium wasabiae and Pectobacterium brasiliensis, but no effect was observed against Candida albicans across all extracts tested.