Evaluation of bioactive compounds and antibacterial activity ofPulicaria jaubertiiextract obtained by supercritical and conventional methods

Pulicaria jaubertii(PJ) is a fragrant herb traditionally used in medication and as a food seasoning. To date, there are no studies on the use of supercritical fluids extraction with carbon dioxide (SFE-CO2) on PJ. This study evaluates and compares the Total phenolic contents (TPC), antioxidant activity by DPPH center dot, antioxidant capacity by ABTS(center dot+), and antibacterial activities of the PJ extract. Extraction was done by using two different methods namely, SFE-CO(2)with 10% ethanol (EtOH) as a co-solvent and conventional extraction by Shaking (Sh) with two solvents (EtOH and water) with different concentrations (100, 70, 50, 30 and 0% v/v). The highest extraction yield and antioxidant capacity were obtained by Sh-EtOH 50% [13.9% and 91.24 Trolox equivalents per g dry extract (mg TE/g DE)] respectively. The extract obtained by Sh-EtOH 70% represented the highest TPC and antioxidant inhibition values (899.02 mg gallic acid equivalents (GAE)/g DE and 76.93%) respectively. The SFE-CO(2)extract has significantly greater antimicrobial activity and is more effective against Gram-positive bacteria. The most sensitive bacterium wasB. subtilis, while the most resistant bacterium wasP. aeruginosa. The optimum values of minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) againstB. subtiliswere noticed in SFE-CO(2)extract (0.4 mg/ml) for both. Overall, the results of this study indicated that PJ is a good source of TPC, antioxidants, and antibacterial compounds.