Clinical Study to Evaluate the Possible Efficacy and Safety of Minocycline in Patients With Ulcerative Colitis Treated With Mesalamine

Most conventional UC therapies rely primarily on downregulating aberrant immune responses and inflammatory cascades. Mesalamine and corticosteroids are the mainstays in management of UC. However, 20% to 32% of UC patients do not respond to steroid.4 Some antibiotics offer protection against experimental and clinical colitis.

Mesalazine (also known as mesalamine or 5- amino salicylic acid, 5-ASA) has a well-established role in UC management. It is the first line therapy for mild to moderate UC and it is considered the cornerstone in the management of UC. The mechanism of action of mesalazine is diverse. It acts locally on colonic mucosa and reduce inflammation by several anti-inflammatory processes. It has a potent antioxidant and free-radical scavenger properties.

Nitrosative stress caused by inducible nitric oxide synthase (iNOS)-derived nitric oxide (NO) production and matrix metalloproteinases (MMPs) have been shown to play an important role in the pathogenesis of UC. As in human UC, expression of MMPs and iNOS are also implicated in the pathogenesis of experimental colitis, Therefore, it is important to develop and evaluate agents that have low-severity adverse effects that can treat UC by blocking inflammatory responses involved in nitrosative stress and/or MMP activation.

Minocycline, a semisynthetic tetracycline, is a safe, widely used and inexpensive antibiotic with a broad spectrum.

Several recent studies have demonstrated that, in addition to its antimicrobial effects, minocycline exerts anti-inflammatory, antiangiogenic, and antiapoptotic effects. These biological effects of minocycline have been shown to have a therapeutic or preventive effect in neurodegenerative disease, neural ischemic damage, ischemic renal injury, rheumatoid arthritis, acne vulgaris, pyoderma gangrenosum, and periodontitis. The mechanisms by which minocycline alleviates these illnesses involve suppressing expression and/or activity of iNOS, MMPs, TNF-α and caspases, and blocking cytochrome-c release. Several animal models of intestinal inflammation have been established, although some only partially resemble human UC.