Author(s): Okolie Ngozi Paulinus*, Agu Kinsley and Eze Gerald Ikechi
The study was carried out to investigate the effect of ethanolic leaf extract of Annona muricata, ELAM on some early changes in cycas-induced colorectal carcinogenesis in rats. 7 groups of male Wistar rats (10 rats /group) were used. Groups were fed either mash alone or mash mixed with 5 % (w/w) cycas leaf powder. ELAM (100 mg/kg body weight) was administered before, simultaneously with, or after exposure to 5 % (w/w) cycas, for 30 days. After sacrifice, colon sections were dissected out for histological and some biochemical analysis. Results showed that cycas alone caused significant decreases in colon total protein (p <0.05), but administration of cycas with ELAM (irrespective of which came first) led to reversal of these decreases, with colon protein restored to levels higher than values for controls. Cycas-induced increases in LDH were significantly (p <0.05) reduced by ELAM. Colon SOD, catalase and GPx activities were significantly decreased in the group fed cycas, while these enzymes were significantly increased above control values in the groups fed both cycas and ELAM (p <0.05). In addition, the cycas-treated group had significant elevation of colon MDA, but MDA levels were significantly lowered in the groups fed cycas and ELAM. Histology results revealed early cancer-related morphological changes in the cycas group, including mucosal erosion, oedema and glandular hyperplasia. These lesions were absent in the groups given ELAM and cycas, irrespective of the duration of ELAM exposure. These results demonstrate evidence for protective role of ELAM in early biochemical events associated with colorectal carcinogenesis in rats.