Liver Toxicity of Raw and Processed Cycas circinalis (Madu) Seed Flour: An Animal Study

Abstract

Various parts of Cycas circinalis (Sinhala: Madu) are used as food or in food preparation in many countries. Flour made from mature dried seeds is used in Sri Lanka to prepare starchy staples such as pittu and roti. However, the seeds are reported to contain hepato-toxins known as cycasins. This study was conducted to observe the liver toxicity, if any, of foods made incorporating cycas seed flour as data on effects of processing on liver toxicity are not available. The study was conducted with pittu and roti made by incorporating cycas seed flour obtained from soaked and dried seeds. Toxicity of pittu, roti and raw flour were observed by assessing the behavior of animals, liver enzymes and histopathological changes in liver sections of the mice fed diets made by incorporating pittu, roti and raw flour for 28 days. Significant elevations in liver enzymes (p<0.05) (reference AST 195 ± 38, ALT 21.2 ± 1.1 IU/L, raw flour AST 345 ± 71, ALT 50.8 ± 3.1 IU/L; pittu AST 406 ± 68, ALT 39.2 ± 1.1 IU/L; roti AST 333 ± 31, ALT 28.8 ± 1.5 IU/L) were observed in rats fed cycas flour incorporated diets. Fatty inclusions, few scattered lymphocytes and mild perpendicular inflammations were observed in the liver sections of all test groups. However, the elevation of liver enzymes and histopathological changes were significantly low (p<0.05) in mice fed with roti incorporated diet when compared to other test groups. Hence, the present study suggests that dry heat processing is detoxifying hepato-toxins in seeds to a certain extent. However, the present study confirms that continuous feeding of raw or processed cycas flour containing food could lead to liver parenchymal cell damage.

KEYWORDS: Cycas circinalis, liver toxicity, cycasins, roti, pittu