Abstract
This study evaluates the antioxidant and antimicrobial activities of HPLC-characterized extracts from Juniperus thurifera (L.) leaf extract (ELJT), bark extract (EBJT), and fruit extract (ESJT). The HPLC analysis of the hydroethanol extract of EBJT identified several key constituents, notably urocanic acid. In terms of antioxidant potential, the DPPH assay showed that both the EBJT and ESJT extracts had significant free radical scavenging activity. The IC(50) values for EBJT and ESJT were 43 µg/mL and 77 µg/mL, respectively. These values indicate that EBJT has a stronger capacity to neutralize free radicals compared to ESJT. For comparison, the positive control (BHT) showed a significantly lower IC(50), underscoring the fact that while the extracts exhibit antioxidant activity, their effectiveness is still relatively weaker than that of BHT. In the FRAP assay, the EC(50) values for EBJT and ESJT were 256 µg/mL and 261 µg/mL, respectively, indicating similar antioxidant efficacy between the two extracts. Again, both extracts show antioxidant potential, but still fall short of the control's activity. The extracts exhibited significant antibacterial activity against S. aureus, E. coli, B. subtilis, and P. mirabilis, with ELJT displaying the strongest effect, characterized by large inhibition zones and low MIC values. This highlights the superior antibacterial potential of the leaf extract compared to the bark and fruit extracts. Regarding antifungal activity, EBJT demonstrated notable efficacy against A. niger, A. flavus, and F. oxysporum, with substantial inhibition zones and relatively low MIC values. Against C. albicans, all extracts showed significant inhibition, with EBJT exhibiting the highest inhibition zone (29.5 mm) and a MIC of 65.29 µL/mL. The J. thurifera extracts, especially ELJT, show promising antioxidant and antimicrobial activities, though less effective than positive controls. Despite this, they remain valuable sources of bioactive compounds for further study and potential applications.