In vitro antioxidant and antimicrobial activities of aerial parts of Algerian Jurinea humilis DC (Asteraceae)

Purpose: To assess the polyphenolic composition of various solvent extracts of Jurinea humilis DC. as well as their in vitro biological effects. Methods: The crude extracts of the aerial parts of Jurinea humilis were obtained by maceration method with dichloromethane (DCM), methanol (MeOH) and ethyl acetate (EtoAC), separately. Folin-Ciocalteu and aluminum chloride procedures were used to quantify the total phenolic and flavonoid contents, respectively, while antioxidant properties were determined by two methods: phosphomolybdenum and DPPH assays. Antimicrobial activity was also evaluated by disc diffusion method. Results: The ethyl acetate extract exhibited the highest amount of total phenolic content (TPC, 169.14 ± 7.22 mg gallic acid equivalent/g sample) and total flavoniod contents (TFC, 104.91±0.22 mg rutin equivalent/g sample). The extract (EtoAC) also showed the strongest antioxidant activity of the three extracts, especially DPPH assay (IC50 = 0.16 ± 0.00 mg/mL), as well as demonstrated the highest activity against the pathogenic strains tested. Conclusion: The results suggest that J. humilis DC. is rich in phenolic and flavonoid contents which may be responsible for good antioxidant and antimicrobial properties. Thus, J. humilis may be a promising source of new antioxidant agents and pharmaceuticals. Keywords: Jurinea humilis, Phenolic, Flavonoid, Antioxidant, Antimicrobia