Antioxidant enzyme synthesis in response to orange oil treatment. Immunoblot analysis demonstrating expression of HO-1, NQO1 and GCLm proteins at 6, 12 and 24 hrs following 15 min treatment of BEAS-2B cells with the oil preparation or time-matched soy oil control. Representative blots from one of three separate experiments are shown above. Densitometric evaluations of each target protein blot normalized to its corresponding GAPDH for all three experiments are provided below. Bars represent mean ± SEM.