Effects of KOB03 on TNF-α levels in the serum and in the nasal tissues of OVA sensitization/challenge-induced AR guinea pigs. (A) The concentration of TNF-α in the sera of guinea pigs was measured by ELISA. Independent experiments were performed (n = 10 per group), and the data shown indicate the mean ± SD. A difference was considered statistically significant when ***P < 0.001 vs. normal (a) or OVA-control (b). (B) The expression of TNF-α in the nasal mucosa was observed by immunohistochemistry (magnification × 100). a, normal; b, OVA control; c, OVA + KOB03 (200 mg/kg)-administrated group; d, OVA + KOB03 (500 mg/kg)-administrated group; and e, OVA + ketotifen (10 mg/kg)-administrated group.