Effects of bromelain, melatonin, and thymoquinone on neutrophil extracellular trap formation and macrophage polarization in experimental periodontitis

Periodontitis is a chronic inflammatory disease characterized by dysregulated immune responses leading to alveolar bone loss. Formation of neutrophil extracellular traps and macrophage polarization play critical roles in its pathogenesis, and natural agents with immunomodulatory properties are being investigated as potential adjunctive therapies. Objective: This study aimed to compare the effects of systemically administered melatonin, bromelain, and thymoquinone on serum neutrophil extracellular trap formation and macrophage polarization in experimental periodontitis. Methodology: Forty rats were assigned to five groups: control, experimental periodontitis, and experimental periodontitis treated with melatonin, bromelain, or thymoquinone. Periodontitis was induced by ligature placement for 14 days. After ligature removal, the treatment groups received daily oral doses of melatonin, bromelain, or thymoquinone for 14 consecutive days. Biochemical, histologic, histomorphometric, and immunohistochemical analyses were performed. Comparisons between groups were performed using one-way ANOVA. Neutrophil extracellular trap levels measured before and after treatment within the same group were analyzed using a paired t-test. Results: Thymoquinone treatment significantly reduced alveolar bone loss compared to the bromelain and melatonin groups (p=0.00). The highest value was observed in the Periodontitis group and the lowest in the Thymoquinone group for neutrophil extracellular trap levels, with intergroup comparisons showing no statistically significant differences (p=0.597). All immunohistochemical analyses showed significant differences in all treatment groups compared to both the control and periodontitis groups (p=0.000). CD68(+) macrophages were most abundant in the periodontitis group and least in the Melatonin group (p=0.00). CD80 expression was highest in the Melatonin group and lowest in the Thymoquinone group (p=0.000), while CD206 expression was highest in the Bromelain group and lowest in the Thymoquinone group (p=0.00). Conclusion: Thymoquinone exhibited comparatively more favorable patterns, and overall, all agents showed trends that may support their consideration as adjunctive approaches in periodontitis management.

Journal

JOURNAL OF APPLIED ORAL SCIENCE

Year

2026

Volume

34

ISSN

1678-7757

eISSN

1678-7765

DOI

10.1590/1678-7765-2025-0699

WoS UID

WOS:001696017600001