Deposition of trans fatty acid from industrial sources and its effect on different growth phases in rats.

Although the effects of trans fatty acids (TFA) from industrially produced sources (IP-TFA), such as partially hydrogenated vegetable oil, are reported, their implications on metabolism and growth are still not fully disclosed. In this study, female Wistar rats were assigned to control diet (AIN-93G) or Trans diet groups (5% IP-TFA) after gestation. The male offspring were classified and grouped as infant, weanling, and young adult (YA) rats (n = 10), and received the same control or Trans diets throughout their life span. Samples of abdominal adipose tissue, liver and plasma were collected to determine fatty acid profile and fasting glycemia. Morphometric analysis of the liver and hepatosomatic index determination were conducted. Deposition of TFA was observed in the liver, adipose tissue and plasma of IP-TFA-fed rats. Fasting glycemia concentration was higher in Trans YA rats than in the control YA group (p = 0.004). A higher accumulation of fat was observed in the liver of the Trans group than in the control group during the three phases. Hepatosomatic index was higher in the YA Trans group than in the YA control group (p < 0.05). Dietary TFA was deposited in the tissues and plasma and raised fasting glucose in growing rats.

Fish oil ingestion reduces the number of aberrant crypt foci and adenoma in 1, 2-dimethylhydrazine-induced colon cancer in rats

We determined the effect of fish oil (FO) ingestion on colonic carcinogenesis in rats. Male Wistar rats received 4 subcutaneous injections (40 mg/kg body weight each) of 1,2-dimethylhydrazine (DMH) at 3-day intervals and were fed a diet containing 18 percent by weight FO (N = 10) or soybean oil (SO, N = 10) for 36 weeks. At sacrifice, the colon was removed, aberrant crypt foci were counted and the fatty acid profile was determined. Intestinal tumors were removed and classified as adenoma or carcinoma. Liver and feces were collected and analyzed for fatty acid profile. FO reduced the mean (± SEM) number of aberrant crypt foci compared to SO (113.55 ± 6.97 vs 214.60 ± 18.61; P < 0.05) and the incidence of adenoma (FO: 20 percent vs SO: 100 percent), but carcinoma occurred equally in FO and SO rats (2 animals per group). The polyunsaturated fatty acid (PUFA) profile of the colon was affected by diet (P < 0.05): total ù-3 (FO: 8.18 ± 0.97 vs SO: 1.71 ± 0.54 percent) and total ù-6 (FO: 3.83 ± 0.59 vs SO: 10.43 ± 1.28 percent). The same occurred in the liver (P < 0.05): total ù-3 (FO: 34.41 ± 2.6 vs SO: 6.46 ± 0.59 percent) and total ù-6 (FO: 8.73 ± 1.37 vs SO: 42.12 ± 2.33 percent). The PUFA profile of the feces and liver polyamine levels did not differ between groups (P > 0.05). In conclusion, our findings indicate that chronic FO ingestion protected against the DMH-induced preneoplastic colon lesions and adenoma development, but not against carcinoma in rats.

Fish oil ingestion reduces the number of aberrant crypt foci and adenoma in 1,2-dimethylhydrazine-induced colon cancer in rats.

We determined the effect of fish oil (FO) ingestion on colonic carcinogenesis in rats. Male Wistar rats received 4 subcutaneous injections (40 mg/kg body weight each) of 1,2-dimethylhydrazine (DMH) at 3-day intervals and were fed a diet containing 18% by weight FO (N = 10) or soybean oil (SO, N = 10) for 36 weeks. At sacrifice, the colon was removed, aberrant crypt foci were counted and the fatty acid profile was determined. Intestinal tumors were removed and classified as adenoma or carcinoma. Liver and feces were collected and analyzed for fatty acid profile. FO reduced the mean (+/- SEM) number of aberrant crypt foci compared to SO (113.55 +/- 6.97 vs 214.60 +/- 18.61; P < 0.05) and the incidence of adenoma (FO: 20% vs SO: 100%), but carcinoma occurred equally in FO and SO rats (2 animals per group). The polyunsaturated fatty acid (PUFA) profile of the colon was affected by diet (P < 0.05): total omega-3 (FO: 8.18 +/- 0.97 vs SO: 1.71 +/- 0.54%) and total omega-6 (FO: 3.83 +/- 0.59 vs SO: 10.43 +/- 1.28%). The same occurred in the liver (P < 0.05): total omega-3 (FO: 34.41 +/- 2.6 vs SO: 6.46 +/- 0.59%) and total omega-6 (FO: 8.73 +/- 1.37 vs SO: 42.12 +/- 2.33%). The PUFA profile of the feces and liver polyamine levels did not differ between groups (P > 0.05). In conclusion, our findings indicate that chronic FO ingestion protected against the DMH-induced preneoplastic colon lesions and adenoma development, but not against carcinoma in rats.