In Vitro Shoot Cultures as an Improved Source of Bioactive Molecules from The Medicinal Halophyte PolygoIn Vitro Shoot Cultures as an Improved Source of Bioactive Molecules from The Medicinal Halophyte Polygonum Maritimum L.num Maritimum L.

Polygonum maritimum L. (sea knotgrass) is a halophyte known for its diverse biological activites. This study explored the in vitro shoot culture of P. maritimum as an improved source of bioactive metabolites when elicited with different concentrations of 0 (control), 50, 100, and 200 μM of salicylic acid (SA). The extract was evaluated for total phenolic and flavonoid content (TPC & TFC). The antioxidant potential was evaluated by DPPH and ABTS-radical scavenging, iron reducing and copper chelating (FRAP & CCA). High antioxidant activity was recorded at the 50 μM SA treatment across all assays with EC50 values ranging between (0.10 ± 0.00 and 1.55 ± 0.13) for the shoots, and (0.06 ± 0.00 and 6.42 ± 0.05) for the roots. The TPC and TFC had the highest value at 50 μM SA treatment for the shoots (54.7 ± 6.7 mg GAE/g DW and 138.6 ± 21.7 mg RE/g DW, respectively). Eighteen compounds were identified, including 4 phenolic acids and 11 flavonoids. Our results showed that in vitro shoot cultures of P. maritimum elicited with salicylic acid are a potentially enhanced source of bioactive secondary metabolites.