Chemical composition and biological evaluation of traditional algerian plants Melissa officinalis L. and Urtica dioica L.

Melissa officinalis L. and Urtica dioica L. were investigated for their phytochemical profiles as well as their antioxidant and anti-lithiatic properties. LC-MS/MS analysis revealed that M. officinalis possessed a more complex and diverse composition, particularly rich in flavonoids (myricetin, and quercetin derivatives) and phenolic acids (caffeic, oleanolic, and salicylic), especially in its ethyl acetate fraction, indicating their lipophilic nature. In contrast, U. dioica exhibited a simpler chemical profile, with significant amounts of myricetin, riboflavin, sinapic acid, catechin, and β-carotene in its aqueous fraction. These compositional differences correspond to distinct biological activities. Antioxidant assays (DPPH, ABTS, FRAP) indicated that the ethyl acetate fraction of M. officinalis exhibited the highest radical-scavenging activity. Furthermore, its aqueous extract showed significant anti-lithiatic efficacy, inhibiting calcium oxalate crystal formation by 87.12% at a concentration of 2 mg/mL.