Publication:

Effect of ethanolic propolis extract on TNF-α, caspase-3 expression and histopathological findings in hypoxic skin flaps: an experimental study in rats

Background Hypoxia remains a major cause of skin flap failure due to excessive production of reactive oxygen species (ROS), which triggers inflammation and apoptosis through increased expression of tumor necrosis factor-alpha (TNF-α) and caspase-3. Propolis contains bioactive compounds with antioxidant and anti-inflammatory properties that may improve skin flap survival under hypoxic conditions. This study aimed to evaluate the effect of ethanolic propolis extract on TNF-α expression, caspase-3 expression, and histopathological changes in a hypoxic skin flap model.

Methods An experimental post-test only control group study was conducted using 24 male Rattus norvegicus divided into four groups (n=6/group): control, P1, P2, and P3. Different flap dimensions (1/3, 1/2, and 2/3) were used to induce varying degrees of hypoxia. Ethanolic extract of Gunung Lawu propolis was administered orally at a dose of 800 mg/kg bw/day for seven days. TNF-α and caspase-3 levels were measured using enzyme-linked immunosorbent assay (ELISA). Histopathological evaluation included necrosis, acute inflammation, and re-epithelialization. Statistical analysis was performed using one-way ANOVA followed by post hoc tests and Kruskal–Wallis analysis.

Results Propolis administration significantly reduced TNF-α levels in all treatment groups compared with controls (p 0.05).

Conclusions Ethanolic propolis extract effectively attenuated inflammatory and apoptotic responses in hypoxic skin flaps by reducing TNF-α and caspase-3 expression. Although histopathological improvements were observed, they did not reach statistical significance. Propolis may serve as a promising adjunctive therapy to enhance skin flap viability.