An assessment of the carcinogenic potential of shea oleine in the rat

Shea oleine, an oil fraction derived from the nut of the tree Butyrospermum parkii, is used as a frying oil. As part of a series of studies, this inve stigation examined the carcinogenic potential of 15% (w/w) Shea oleine in c omparison with 15% (w/w) sheanut oil, and palm oil following dietary admini stration to rats over 104 weeks. The assessment comprised an evaluation of mortality, clinical signs, body weight, food intake, clinical pathology, or gan weights and macroscopic and histopathological examination plus tumour t ype and incidence evaluation. Results showed that shea oleine produced no a dverse effects and no evidence of tumorigenic potential compared to other c ommercially available sheanut and palm oils in the rat. Notable differences were confined to reduced body weight gain and food intake, reduced cholest erol and increased alkaline phosphatase levels, reduced heart weight and an increased incidence of pulmonary lipidosis with shea oleine diets. The lat ter effect may reflect a naturally lower incidence of this finding with pal m oil diets. Tumour findings, specific to shea oleine diets, were restricte d to an increase in the number of hepatomas for females, pancreatic exocrin e adenomas for males and skin keratoacanthomas for males fed shea oleine di ets. The increase in the incidence of hepatomas with treatment was thought to be related to the high fat content of the diets. The incidence of these tumour findings was similar to that given in published data for the Wistar rat, or the 'in house' values For tumour incidence in rats fed high-fat die ts. In conclusion, none of the findings in this study were considered to be adverse effects. In comparison with other commercially available edible oi ls, shea oleine showed no tumorigenic potential following dietary administr ation at 7.5 g/kg/day in the rat. (C) 2001 Elsevier Science Ltd. All rights reserved.