Comparative study on the effects of ointments of tinidazole, hydrocortisone and clobetasol on animal models for inflammatory dermatitis in mice.

To understand further the possible clinical effects of tinidazole ointment at relatively high concentration (2%) for atopic dermatitis (AD), we performed a comparative study with readily available topical corticosteroids, clobetasol propionate (0.005 or 0.05%) and hydrocorotisone butyrate (0.1%) (hereafter referred as clobetasol and hydrocortisone, respectively), on inflammatory dermatitis in mice. We also observed the effects of combined application of tinidazole with clobetasol (0.005%, one tenth of the clinical use) in comparison with tinidazole itself, clobetasol (0.05%) or hydrocortisone (0.1%) on the animal model. All ointments suppressed inflammatory dermatitis induced by trinitrochlorobenzen (TNCB) or oxazolone. The rank order of the potency to suppress the ear edema was clobetasol (0.05%), tinidazole (2%) with clobetasol (0.005%) > clobetasol (0.005%) > tinidazole (2%) in TNCB-induced dermatitis, and hydrocortisone (0.1%), clobetasol (0.05%) > tinidazole (2%), tinidazole with clobetasol (0.005%) > clobetasol (0.005%) in case of oxazolone-induced dermatitis. We confirmed that tinidazole (2%) suppresses immediate and late phase reactions in mice passively sensitized with anti-DNP IgE Mab. In addition, tinidazole (2%) was much more potent than hydrocortisone (0.1%) in suppressing the amount of scratching, presumably due to itching, in passively sensitized mice. These results indicate that the advantage of using ointments of tinidazole would be that it has stronger anti-itching effects than corticosteroids.