Nicotine and ulcerative colitis

Growth of M. avium subspecies paratuberculosis in culture is enhanced by nicotinic acid, nicotinamide, and α and β nicotinamide adenine dinucleotide

BACKGROUND

Without known mechanisms of action, Crohn's disease is exacerbated, and ulcerative colitis is improved, by the use of tobacco. Mycobacterium avium subspecies paratuberculosis (MAP) may be zoonotic. We hypothesized that tobacco components might alter the growth kinetics of MAP, explaining these divergent clinical observations.

METHODS

The effect of nicotine, nicotinic acid, nicotinamide and α and β nicotinamide adenine dinucleotide (α and β NAD) were studied on eight strains of three mycobacterial species (MAP, M. avium and M. tb. complex). Data are obtained as "cumulative growth index," (cGI) and presented as "percent increase in cumulative GI" (% + ΔcGI).

RESULTS

Nicotinic acid enhances the two human MAP isolates (Dominic; 225% + ΔcGI and UCF-4; 92% + ΔcGI) and M. avium (ATCC 25291; 175% + ΔcGI). Nicotinamide (at 6.4 µg/ml) enhances the human MAP isolates (Dominic; 156% + ΔcGI and UCF-4; 79% + ΔcGI) and M. avium (ATCC 25291; 144% + ΔcGI.) Both α and β NAD enhance Dominic; (135 and 150 % + ΔcGI) and UCF-4; (81 and 79% + ΔcGI). At the doses tested, nicotine has no effect on any strain studied.

CONCLUSIONS

We show enhancement of MAP growth by nicotinic acid, one of ≥4,000 tobacco-related molecules, its amide, nicotinamide and α and β NAD. Pure nicotine has no enhancing effect at the doses studies.

The role of cigarettes and nicotine in the onset and treatment of ulcerative colitis

Epidemiological evidence suggests that ulcerative colitis is a disease of nonsmokers, while Crohn's disease is a disease of smokers. The relative risk of developing ulcerative colitis is not only greater in nonsmokers, in addition there appears to be a rebound effect in smokers who quit, with the heaviest (ex-)smokers increasing their relative risk of the disease the most. This factor poses an ethical dilemma for health professionals giving advice on stopping smoking, which may thus have a serious detrimental effect on the health of some patients. Nicotine is believed to be the pharmacological ingredient of tobacco that is responsible for this beneficial effect and several clinical trials using nicotine have demonstrated it to be an effective therapeutic agent in the treatment of ulcerative colitis. Although the aetiology of ulcerative colitis is unclear, current research using nicotine-based products has produced some interesting clues, together with the possibility of some form of therapeutic treatment based on nicotine administration.

Transdermal nicotine for active ulcerative colitis

BACKGROUND

Ulcerative colitis is largely a disease of nonsmokers. Because anecdotal reports suggest that smoking and nicotine may improve the symptoms of the disease, we examined the effect of nicotine as a supplemental treatment for ulcerative colitis.

METHODS

We treated 72 patients with active ulcerative colitis with either transdermal nicotine patches or placebo patches for six weeks in a randomized, double-blind study. Incremental doses of nicotine were given; most patients tolerated doses of 15 to 25 mg per 24 hours. All the patients had been taking mesalamine, and 12 were receiving low doses of glucocorticoids; these medications were continued without change during the study. Clinical, sigmoidoscopic, and histologic assessments were made at base line and at the end of the study; symptoms were recorded daily on a diary card, and the clinician made a global assessment. Side effects and plasma nicotine and cotinine concentrations were monitored throughout the study.

RESULTS

Seventeen of the 35 patients in the nicotine group had complete remissions, as compared with 9 of the 37 patients in the placebo group (P = 0.03). The patients in the nicotine group had greater improvement in the global clinical grade of colitis (P < 0.001) and the histologic grade (P = 0.03), lower stool frequency (a difference of 1.6 stools daily; P = 0.008), less abdominal pain (P = 0.05), and less fecal urgency (P = 0.009). More patients in the nicotine group had side effects (23, vs. 11 in the placebo group; P = 0.002), the most common of which were nausea, lightheadedness, headache, and sleep disturbance. Withdrawals due to ineffective therapy were more common in the placebo group (3 vs. 8, P = 0.12).

CONCLUSIONS

The addition of transdermal nicotine to conventional maintenance therapy improves symptoms in patients with ulcerative colitis.

Effect of nicotine and cotinine on the production of oxygen free radicals by neutrophils in smokers and non-smokers

1. Neutrophils play a role in the pathogenesis of ulcerative colitis. Most of the patients with ulcerative colitis are non-smokers. 2. Neutrophil function was examined in healthy males, five smokers and five non-smokers, measuring production of oxygen free radicals by chemiluminescence. 3. The chemiluminescence was examined in the presence of nicotine and its main metabolite cotinine in various concentrations. 4. 10 mM nicotine inhibited production of oxygen free radicals (90.2% +/- 11.6) compared with controls (P less than 0.001), as did the same concentration of cotinine (58.9% +/- 34.2), (P less than 0.05). 5. 1 mM solutions had no effect and 3 mM nicotine was required to achieve 50% inhibition. 6. Smokers and non-smokers did not differ. 7. Since plasma concentrations of nicotine after a cigarette are only between 5 and 15 mM, the observed effects of nicotine and cotinine in much higher pharmacological concentrations in this system are unlikely to be of clinical relevance in ulcerative colitis.