MN-001, a novel oral anti-inflammatory agent, suppresses bladder hyperactivity in a rat model

OBJECTIVE: To evaluate the effects of MN-001, a novel orally active anti-inflammatory agent, in suppressing the bladder hyperactivity resulting from ovalbumin (OA)-induced mast-cell stimulation in a rat model. MATERIALS AND METHODS: Sprague-Dawley rats of both sexes were divided into five groups of 10 each, with group 1 as the control and groups 2-5 undergoing OA sensitization to produce mast-cell degranulation using an established method. At 14 days after sensitization, rats were given an acute intravesical challenge: in group 1, by saline (control), and in groups 2-5, with approximately 2 mL of OA (10 mg/mL in sterile saline). Groups 3-5 received the investigational agent MN-001 orally at 10, 30 or 50 mg/kg, respectively, 1 h before intravesical OA challenge. Urodynamics were then evaluated to quantify the frequency of contractions (voids), intercontractile interval (ICI) and non-voiding contractions (NVCs). RESULTS: Acute intravesical OA challenge in rats in group 2 caused contractions of bladder smooth muscle, leading to a significant (P < 0.05) dose-dependent increase in NVCs and a decrease in ICI. Rats pre-treated with MN-001 at 30 and 50 mg/kg (groups 4 and 5) had significantly fewer NVCs and a greater ICI than rats in group 2 (P < 0.05). CONCLUSION: OA challenge in OA-sensitized rats produces bladder hyperactivity, as reflected in significantly more NVCs and a lower ICI. At doses of 30 and 50 mg/kg orally, MN-001 produces significant protection against the OA-induced bladder hyperactivity. MN-001 might have a role in managing mast cell activity and the associated bladder symptoms in patients with interstitial cystitis.