Localization of TNF-a in Experimentally Induced Bone Defect Treated with Topical Application of Flavanoids Extract of Hibiscus Sabdariffa

Background Repair of bone defect is a multistep procedure involving migration, proliferation, differentiation and activation of several cell types. Many cytokines which play an important role in the regulation of bone repair, Tumor necrosis factor-a (TNF-a) is one of the several proinflammatory cytokines involved in bone remodeling (Osta et al. , 2014). TNF_a possessed osteogenic differentiation effects, its determined promoter of osteoclastogenesis and inhibitor of osteoblastogenesis. The use of plants for healing purposes predates human history and forms the source of current modern medicine. This study was achieved to investigate effect of flavonoid extract on molecular events in bone healing process by expression of Tumer Necrosis Factor-alpha (TNF-). Materials and methods Immunohistochemica localization of TNF- was investigated for healing of induced bone defects in tibiae of 24 adult New Zealand rabbits. Two holes were induced in rabbit tibia the left side left to heal normally as control, while, the other hole made on the right side filled with flavonoid extract regarded as experimental. Sacrification of the animals were done according to the healing periods. Routine processing and sectioning technique was performed for immunohistochemical evaluation. Results Findings obtained in this study showed decrease in percentage of positively stained bone marrow stromal cells (BMSC) between experimental and control groups with statically significant difference among (3days, 1, and 2weeks) durations, while, in 4 weeks duration there was no obvious difference and its statistically non-significant. Positive expression of TNF- by osteoblasts and osteocytes was statistically significant at 1week, non-significant at 4weeks, however at 2weeks statically significant analysis was recorded with osteocytes and osteoclasts. Conclusion The study revealed obvious effect of flavonoid extract in promoting bone healing process as demonstrated TNF- expression by cells involved in in the process in different durations.