Bioactive potential of Pulicaria undulata from arid regions against multidrug-resistant pathogens and cancer cells

The demand for medicinal plants in the pharmaceutical industry has recently increased. Pulicaria undulata (“wild marjoram” or “butterfly bush”) has long been used in folk medicine. This study evaluates the antioxidant, antimicrobial, antibiofilm, antiviral, and anticancer activities of the petroleum ether extract from P. undulata’s flowering parts grown in the desert. Preliminary phytochemical screening indicated the presence of several secondary metabolite classes, while HPLC profiling revealed multiple detectable phenolic and flavonoid-related compounds. HPLC analysis identified 19 bioactive compounds, with major components including apigenin (9.54%), ellagic acid (9.40%), coumaric acid (9.21%), daidzein (8.23%), cinnamic acid (7.88%), and chlorogenic acid (5.30%). P. undulata extract exhibited significant antioxidant activity, with IC50 values of 4.81 ± 0.134 mg/mL and 7.84 ± 0.351 mg/mL by DPPH and FRAP assays, respectively. The extract also showed potent antibacterial and antibiofilm effects against four multidrug-resistant isolates: S. aureus, K. pneumoniae, A. baumannii (12.5 mg/mL), and E. faecalis (25 mg/mL). At 125 µg/mL, the extract demonstrated antiviral activity against CoxB4 and HSV-1 with inhibition rates of 10.45% and 9.28% (P ≤ 0.05). Additionally, P. undulata caused DNA fragmentation in liver cell lines, indicating cytotoxic effects, with IC50 values of 666.75 µg/mL for Vero cells and 137.77 µg/mL for MCF-7 cells. In conclusion, P. undulata represents a potential source of natural, eco-friendly compounds for pharmaceutical and health-related products, enhancing their commercial value.