Number of macrophages and transforming growth factor β expression in citrus limon L. Tlekung peel oil-treated traumatic ulcers in diabetic rats

Purpose: To analyse the potential use of Citrus limon L Tlekung peel oil in the treatment of traumatic ulcers in diabetic rats based on number of macrophages and transforming growth factor β (TGF-β) expression. Method: Standard steam distillation was performed to produce Citrus limon L peel oil with its components subsequently analysed by gas chromatography-mass spectrometry (GC-MS). Diabetes was induced with streptozotocin (STZ) via administration of a single 50 mg/kg dose. A traumatic ulcer was subsequently induced with a 5 mm burnisher heated for 30 s and applied without pressure for 1 s to the lower labial mucosa of the animals. Citrus limon L oil gel containing 3% carboxyl methyl cellulose sodium was then topically administered to the traumatic ulcer for a period of three or five days. TGF-β expression was analysed through immunohistochemical staining and the macrophage number calculated with haematoxylin-eosin stain. Results: The major identified compounds in Citrus limon L peel oil include fumaric (31.78 %), d-limonene (17.38 %), z-citral (13.55 %), L-linalool (8.51 %), geraniol nerol (3.56 %), geraniol (2.94 %,), α-terpineol (1.25 %) and γ-terpinene (1.03 %) together with other minor constituents. Treatment of traumatic ulcers with Citrus limon L peel oil produced higher number of macrophages and TGF-β expression (p = 0.000). Treatment over a period of five days also indicated higher expression of TGF-β and number of macrophages compared to that lasting three days with Citrus limon L peel oil (p = 0.000). Conclusion: Citrus limon L peel oil stimulates TGF-β expression and an increase of macrophage numbers in diabetic subjects during traumatic ulcer healing after three and seven days. Clinical application of Citrus limon L peel oil constitutes a potential therapy in the treatment of traumatic ulcers in diabetic subjects.