Abstract Objective: This study aimed to investigate the effects of systemic administration of P. eurycarpa Yalt. plant extract on alveolar bone loss and oxidative stress biomarkers in gingival tissue in a rat model of experimental periodontitis. Methodology: 32 male Wistar albino rats, weighing 200–250 g, were divided into four groups (n=8): Healthy control (HC), Experimental periodontitis control (EPC), Experimental periodontitis 400 mg/kg (EP400), Experimental periodontitis 800 mg/kg (EP800). Experimental periodontitis was induced using the ligating method. Distilled water was administered to the HC and EPC groups and the plant extract was administered to the EP400 and EP800 groups by oral gavage at doses of 400 mg/kg and 800 mg/kg, respectively. The rats were sacrificed on the 15th day. The values of glutathione peroxidase GSH-Px, malondialdehyde (MDA), superoxide dismustase (SOD), interleukin-1β (IL-1β), interleukin-10 (IL-10), total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI) in the gingival tissues were analyzed by ELISA tests. Alveolar bone loss was assessed using micro-CT images of the maxilla. Results: Although the IL-1β, TOS, OSI results of the healthy control group were lower than those of the other groups, the TAS values were higher (p<0.05). No significant difference was found in the biochemical parameters among the EPC, EP400, and EP800 groups (p>0.05). Alveolar bone loss was significantly reduced in the extract groups compared to the EPC group (p<0.001). Conclusion: Within the limitations of this study, it was observed that the systemic P. eurycarpa extract application reduced alveolar bone loss in a rat model of experimental periodontitis. Further studies are needed to elucidate the beneficial effects of P. eurycarpa. Objective P Yalt Methodology 3 200250 200 250 200–25 g n=8 n8 n 8 (n=8) HC, , (HC) (EPC) 40 mgkg mg kg EP (EP400) 80 EP800. . (EP800) method EP40 EP80 respectively th day GSHPx, GSHPx GSH Px, Px GSH-Px MDA, MDA (MDA) SOD, SOD (SOD) interleukin1β interleukinβ interleukin 1β β IL1β, IL1β ILβ IL (IL-1β) interleukin10 10 interleukin-1 IL10, IL10 (IL-10) TAS, (TAS) TOS (TOS) (OSI tests microCT micro CT maxilla Results 1β, IL-1β p<0.05. p005 p p<0.05 0 05 (p<0.05) p>0.05. p>0.05 (p>0.05) p<0.001. p0001 p<0.001 001 (p<0.001) Conclusion 20025 20 25 200–2 n= (n=8 (HC (EPC 4 (EP400 (EP800 EP4 EP8 (MDA (SOD (IL-1β interleukin1 1 interleukin- IL1 (IL-10 (TAS (TOS p00 p<0.0 (p<0.05 p>0.0 (p>0.05 p000 p<0.00 00 (p<0.001 2002 2 200– (n= (EP40 (EP80 (IL-1 p0 p<0. (p<0.0 p>0. (p>0.0 (p<0.00 (n (EP4 (EP8 (IL- p<0 (p<0. p>0 (p>0. (EP (IL p< (p<0 p> (p>0 (p< (p> (p