Comparative Effects of Thymoquinone, Tranexamic Acid, and Porcine Dermal Collagen on Seroma Formation and Tissue Remodeling After Mastectomy in a Rat Model

Background and Objectives: Seroma formation is the most common postoperative complication following mastectomy and axillary dissection, negatively affecting wound healing and delaying adjuvant therapy. Despite numerous surgical and pharmacological approaches, no universally effective strategies have been established. This study aimed to comparatively evaluate the effects of porcine dermal collagen (PDC), tranexamic acid (TXA), and thymoquinone (TQ) on seroma formation and tissue repair. Materials and Methods: A randomized controlled experimental study was conducted using 40 female Wistar albino rats that underwent modified radical mastectomy and axillary dissection. All surgical and postoperative procedures were performed in accordance with the institutional animal welfare and ethical guidelines, including postoperative analgesic administration. The animals were divided into four groups: control, PDC, TXA, and TQ (n = 10 each). Seroma volume was measured on postoperative day 14. Histopathological evaluation, immunohistochemical analysis (FGF2, VEGF, TGF-β1, p53), and quantitative real-time PCR were performed to assess tissue remodeling and molecular responses. Results: All treatment groups demonstrated a significant reduction in seroma volume compared to the control group, with the most pronounced decrease observed in the TQ and TXA groups (p < 0.0001), while PDC showed a moderate effect (p < 0.01). Histopathological analysis revealed increased collagen deposition and fibrin formation in the PDC and TQ groups, whereas TXA exhibited a more limited remodeling profile than the others. Immunohistochemical and molecular analyses showed significant upregulation of VEGF across all groups, with broader and more consistent increases in the PDC and TQ groups. TGF-β1 and FGF2 expression demonstrated region-specific increases, particularly in the thoracic tissue. p53 expression remained relatively stable in the TXA group but was elevated in specific regions in the PDC and TQ groups. Importantly, the increased inflammatory infiltration, edema, vascular proliferation, and fibrin deposition observed in the TQ group may reflect not only active tissue remodeling processes but also prolonged inflammatory activation and enhanced fibrotic responses and should therefore be interpreted cautiously. Conclusions: PDC, TXA, and TQ differentially modulate postoperative seroma formation via distinct biological mechanisms. While TXA primarily exerts a targeted anti-seroma effect and PDC enhances extracellular matrix stabilization, TQ is associated with broader angiogenic, inflammatory, and tissue remodeling responses within this preclinical rat model. These findings should be considered exploratory and hypothesis-generating, and additional mechanistic studies and clinical investigations are necessary before definitive therapeutic conclusions can be established regarding the use of TQ in human breast surgery settings.