Introduction: Aristolochia longa, is widely used as a medicinal plant, in Algerian folk medicine since ancient times and passed through the generations. This study focused on the qualitative examination of different phytochemical constituents to determine their antioxidant activities.
Materials and Methods: Leaves and roots were extracted by liquid-liquid extraction technique using the methanol as solvent. The total phenolic and flavonoids content was determined by Folin–Ciocalteu and AlCl3 methods, respectively. The antioxidant activity was evaluated with two distinct methods: DPPH radical scavenging assay and ferric reducing antioxidant power test (FRAP). Then, the high-performance liquid chromatography (HPLC) method was performed to analyze leaves and roots n-butanol fractions. 
Results: Leaves gave a significant value of polyphenols (8.580 ± 0.04 mg GAE/g DW). Whereas, n-butanol fraction flavonoids extracted from leaves was observed much highest (4.54 ± 1.94 mg CE/g DW). N-butanol fraction leaves showed a powerful scavenging activity and reducing activity with an IC50 = 0.044 ± 0.001 mg/ml and EC50 = 0.126 ± 0.041 mg/ml, respectively. The HPLC analysis of leaves and roots n-butanol fraction revealed different bioactive compounds in which they belong to the flavonoids category.
Conclusions: The results obtained from this study suggest that Aristolochia longa leaves were considered as an important resource of flavonoids, which have an interesting antioxidant power.