No abstract

In the present study, eight organosulfur compounds from garlic and onions were studied for their inhibitory effects on benzo[a]pyrene (BP)-induced neoplasia of forestomach and lung of female A/J mice when administered 96 and 48 h prior to carcinogen challenge. These compounds had one, two or three linearly connected sulfur atoms. They included the four allyl group-containing derivatives: allyl methyl trisulfide (AMT), allyl methyl disulfide (AMD), diallyl trisulfide (DAT), and diallyl sulfide (DAS), and also four corresponding saturated compounds in which propyl groups were substituted for the allyl groups. All four allylic compounds inhibited BP-induced neoplasia of the forestomach. The saturated analogs were almost without inhibitory activity, indicating the importance of the allyl groups. DAT, which contains two allyl groups, was more potent than AMT, which contains only one allyl group, thus providing further evidence for the role of allyl groups in the inhibitory effects observed. DAS and AMD, but not DAT or AMT, inhibited pulmonary adenoma formation. The fact that in the lung the monosulfide and disulfide inhibited, but the trisulfide did not inhibit, indicates that the number of sulfur atoms in the molecule can control the organ sites at which protection against carcinogenesis will occur. All four allylic compounds induced increased glutathione S-transferase (GST) activity in the forestomach, but varied in their capacity to induce GST in lung, liver and small bowel. Their saturated analogs produced little or no induction. In evaluating relationships between diet and cancer, it would be useful to consider the possible role of garlic and onion organosulfur compounds as protective agents. In addition, further studies of this class of chemicals might lead to the identification and development of useful new chemopreventive compounds.

No abstract

Benzyl isothiocyanate and phenethyl isothiocyanate, two compounds found in cruciferous plants, and phenyl isothiocyanate, a synthetic compound, all inhibit 7,12-dimethylbenz[a]anthracene (CMBA)-induced mammary tumor formation in female Sprague-Dawley rats when administered 4 hours prior to the DMBA. Comparable studies in which benzyl isothiocyanate was administered 24 hours before or 4 hours after DMBA showed almost complete loss of inhibition. Additions of benzyl isothiocyanate or phenethyl isothiocyanate to a diet containing CMBA inhibited formation of neoplasms of the forestomach and pulmonary adenomas in female ICR/Ha mice. Addition of benzyl isothiocyanate to a diet containing benzo[a]pyrene also inhibited carcinogenesis of the mouse forestomach due to this carcinogen. The finding of two additional anutrient dietary compounds which inhibit chemical carcinogenesis focuses on the possibility that dietary constituents of this nature may diminish the impact of exposures to chemical carcinogens.

A pancreatic cancer case-control study was conducted in the Minneapolis-St. Paul area. Family members were interviewed about the subject's usage of cigarettes, alcohol, coffee, and other dietary factors in the two years prior to death (cases, n = 212) or prior to interview (controls, n = 220). The adjusted odds ratio for two packs or more of cigarettes per day was 3.92 (95% CI = 1.18, 13.01)

No abstract

This investigation is part of an effort to develop chemoprevention for carcinogenesis of the lung. It focuses on the efficacy of low doses of synthetic glucocorticoids administered either as single agents or in combination with a second compound, myo-inositol. Glucocorticoids are potent inhibitors of carcinogenesis. The use of low doses is important to avoid potential side-effects. The synthetic glucocorticoid budesonide, administered by aerosol for 20 s three times a week, was studied to determine its effects on benzo[a]pyrene-induced pulmonary adenoma formation in female A/J mice. Two dose levels were employed, 10 and 25 microg/kg body wt. The lower dose produced a 34% reduction in lung tumor formation and the higher dose level a 60% reduction in lung tumors. In additional groups of mice, the effects of 0.3% myo-inositol added to the diet was found to reduce pulmonary tumor formation by 53%. The two agents given in combination resulted in a greater inhibition of lung tumor formation than either by itself. Budesonide at 10 microg/kg body wt plus 0.3% myo-inositol reduced the number of tumors by 60% and budesonide at 25 microg/kg body wt plus 0.3% myo-inositol reduced lung tumor formation by 79%. To determine whether a glucocorticoid other than budesonide would have inhibitory effects in this experimental model, beclomethasone dipropionate administered by aerosol for 20 s three times a week was studied as a single agent and showed almost identical inhibitory properties to budesonide. The doses of the glucocorticoids calculated on a daily basis are within the range of those used widely for control of chronic allergic respiratory diseases in the human. The capacity of low doses of inhaled glucocorticoids to prevent pulmonary neoplasia and the enhancement of this preventive effect by myo-inositol, an essentially non-toxic compound, are findings that should encourage further work to evaluate the applicability of these agents to the prevention of neoplasia of the lung in the human.

Introduction: A phase I, open-label, multiple dose, doseescalation clinical study was conducted to assess the safety, tolerability, maximum tolerated dose, and potential chemopreventive effect of myo-inositol in smokers with bronchial dysplasia. Materials and Methods: Smokers between 40 and 74 years of age with z 30 pack-years of smoking history and one or more sites of bronchial dysplasia were enrolled. A dose escalation study ranging from 12 to 30 g/d of myo-inositol for a month was first conducted in 16 subjects to determine the maximum tolerated dose. Ten new subjects were then enrolled to take the maximum tolerated dose for 3 months. The potential chemopreventive effect of myo-inositol was estimated by repeat autofluorescence bronchoscopy and biopsy.