Antioxidant and antibacterial activity of extract and phases from stems of Spartium junceum L. growing in Algeria

This work aimed to evaluate the antioxidant and antibacterial activities of the hydroalcoholic (80% methanol) extract and n-hexane (n-Hex), chloroform (Chl), ethyl acetate (EtAc), and nbutanol (n-But) phases from Spartium junceum L. stems collected in Algeria. Preliminary phytochemical investigations on phenolic compounds have been carried out. The total phenolic content, spectrophotometrically determined, ranged from 71.8095 ± 3.7136 mg GAE/g (extract) to 0.0582 ± 0.0106 mg GAE/g (n-Hex). By HPLC-PDA analysis flavonoids (flavone derivatives), p-hydroxybenzoic acid, p-hydroxycinnamic acid, and cinnamic acid derivatives were identified both in the extract and phases. S. junceum extract showed a noticeable free radical scavenging effect in the DPPH test (IC50 = 0.6833 ± 0.0240 mg/mL), mild reducing power, and strong chelating activity (IC50 = 0.2292 ± 0.0138 mg/mL). Among the phases, n-But displayed the best effect both in the DPPH test and reducing power assay, whereas n-Hex resulted the most active in the ferrous ions chelating activity assay. A positive relationship between DPPH radical scavenging activity and total phenolic content was found. Both the extract and phases exhibited antimicrobial activity against Gram-positive bacteria only. Staphylococcus aureus ATCC 6538 was the most susceptible strain (MIC range: 15.60-250.00 μg/mL), and the Chl phase showed the greatest efficacy. S. junceum extract resulted non-toxic against Artemia salina. The obtained results demonstrate the potential of S. junceum stems as safe sources of natural antioxidant and antimicrobial compounds.