Abstract
Background: Propolis, a natural flavonoid-rich substance produced by bees, is recognized and used worldwide for various therapeutic applications. Apitherapy studies on Philippine stingless bee (Tetragonula biroi Friese) (PSB) propolis have proven its immunomodulatory, anti-inflammatory, analgesic, and wound-healing properties. However, safety evaluation tests have yet to be conducted. Hence, an acute dermal irritation study of propolis from PSB using New Zealand white (NZW) rabbits was performed. Methods: PSB propolis at a concentration of 2,000 mg/kg body weight (BW) was applied on the dorsum and occluded for four hours. Gross assessment and scoring of skin test site for erythema and edema were done at 0- and 1-hour post-removal of control and test materials and then every 24 hours throughout a 14-day observation period. Results: There was the absence of gross and microscopic changes on the skin as well as morbidity, and mortality with propolis treatment. Conclusions: The results of this study indicate that the propolis from PSB is non-irritating, affirming its safe usage and application in various industries, including the development of biomedical products.
Keywords: acute dermal irritation; edema; erythema; Philippine stingless bee; propolis; New Zealand white rabbits