Prevention of spontaneous and chemically induced carcinogenesis using activated carbon fiber adsorbent. II. Inhibitory effect of the activated carbon fiber adsorbent ‘Aqualen’ on N-methyl-N′-nitro-N-nitrosoguanidine-induced gastric carcinogenesis in rats

Two-month-old female LIO rats were given N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) with tap water in a concentration of 100 mg/1 for 12 months (groups 1 and 2) or were kept without the carcinogen treatment (groups 3 and 4). From the first day of exposure to MNNG rats from groups 2 and 3 were given activated carbon fiber adsorbent Aqualen® in their diet five times per week together with lab chow in a daily dose of 100 mg/kg of body weight. The experiment was finalized 16 months after first exposure to the carcinogen. The total stomach adenocarcinoma incidence was 43% in group 1 and 39% in group 2, whereas invasive stomach adenocarcinomas occurred in 36% and 8% of rats from groups 1 and 2, respectively (P<0.05). Tumors other then stomach sites (duodenum and liver) only developed in rats from group 1 (29%). No lesions were observed in rats exposed to Aqualen without MNNG. Thus, our results demonstrate the inhibitory effect of the activated carbon fiber adsorbent Aqualen® on stomach carcinogenesis in rats.