BackgroundPeganum harmala L. is used in traditional medicine to treat several health ailments. Hence, the present work aimed to investigate the DPPH free radical scavenging, α-amylase, cytotoxic, and antifibrotic effects of the hydrophilic extract and fixed oil obtained from P. harmala seeds.MethodsThe hydrophilic extract and fixed oil of P. harmala were assessed for their abilities to scavenge DPPH free radicals and inhibit α-amylase using reference bioassays. The cytotoxicity was assessed on several cancer and normal cell lines, including B16F1, Caco-2, COLO205, HeLa, Hep 3B and Hep G2, MCF-7, and HEK-293 T cells. The MTS assay was used to evaluate the antifibrotic capabilities utilizing the human hepatic stellate (LX-2) cell line.ResultsP. harmala plant fixed oil has potent DPPH free radical scavenging activity with an IC50 dose of 79.43 ± 0.08 µg/ml. Besides, the hydrophilic extract has a poor anti-α-amylase effect compared with the antidiabetic drug Acarbose, with IC50 doses of 398 ± 0.59 and 25.11 ± 1.22 µg/ml, respectively. In addition, the growth of MCF-7, Hep3B, HepG2, HeLa, COLO205, CaCo2, B16F1, and HeK293t was inhibited by P. harmala hydrophilic extract with IC50 doses of 121.34 ± 1.71, 268.3 ± 0.75, 297.20 ± 1.00, 155.60 ± 1.14, 150.01 ± 0.51, 308.35 ± 0.53, 597.93 ± 1.36, and 5.38 ± 0.99 µg/ml, respectively. In addition, at 1000 µg/ml, 5-Fluorouracil reduced fibrosis cells by 0.089%, while the hydrophilic extract decreased the number of LX-2 cells by 5.81%.ConclusionP. harmala plant-fixed oil exhibits potential antioxidant properties. While the hydrophilic extract showed limited effectiveness as an anti-α-amylase agent and demonstrated notable cytotoxic effects against various tested cancer cell lines. Furthermore, this extract significantly reduces the number of LX-2 fibrotic cells. These findings emphasize the therapeutic potential of these products in managing various health disorders and warrant further investigation into their mechanisms of action and clinical applications.