Duration Dependent Impact of Aspartame and Sacoglottis gabonensis on the Liver of Swiss Mice

Aim: This study aimed at evaluating the duration dependent impact of aspartame and Sacoglottis gabonensis on the liver of male swiss mice.

Location and Duration of Study: The study was carried out in the green house of the Department of Animal and Environmental Biology, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt, Nigeria (Coordinates 4o48’14’'N 6o59’12”E). The experiment lasted for Ninety days.

Experimental Design: A completely randomized experimental design employing relevant statistical tools for analysis and interpretation.

Methodology: Ninety adult male mice were assigned to six groups (A-F) of fifteen mice each. Group A was the negative control and so they were not given any treatment, but only given pellet and clean tap water. Group B was the positive control and received 50mg/kg/bw/day of aspartame alone. Group C received 50mg/kg/bw/day of aspartame and 250mg/kg/bw/day of ethanolic extract of Sacoglottis gabonensis leaf. Group D receive 50mg/kg/bw/day of aspartame and 250mg/kg/bw/day of ethanolic extract of S. gabonensis bark. Group E received 50mg/kg/bw/day of aspartame and 250mg/kg/bw/day of a combination of bark and leaf extract. Group F received 50mg/kg/bw/day of aspartame and 500mg/kg/bw/day of a combination of bark and leaf extract. All the groups were exposed to their treatment by oral gavage for 30, 60 and 90days. Feed was withdrawn from the animals 24hours before the termination of experiment. For Biochemical analysis, blood samples were collected by ocular puncture into sterile tubes and serum separated by centrifugation at 2500 g for 10 mins and stored for determination of some liver biomarkers using their respective kits. For histopathological analysis, 0.5g of Liver was fixed in 10% neutral formalin and sectioned with a digital microtome (AO Spencer, No. 820) at 5 µm thick. Histological sections mounted on slides were stained with Haematoxylin and Eosin (H&E). Photomicrographs were generated at X40 magnification and interpreted.

Results: There was significant (p<0.05) increase in Malondialdehyde (MDA), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in the group B administered aspartame only when compared with the groups co-administered extracts of leaf, bark and combination of Sacoglottis gabonensis. Also, a significant (p<0.05) decrease in the concentrations of superoxide dismutase (SOD), gluthathione (GSH) and catalase (CAT) was recorded in group B when compared to other groups across the experimental period. Groups coadministered S. gabonensis extract showed a significant increase in SOD, GSH and CAT and decrease in MDA compared to the positive control. Histopathological analysis shows the liver epithelium of the negative control group being filled with healthy normal hepatocytes, while liver exposed to aspartame alone (positive control) showed degenerated hepatocytes, multiple necrotic and apoptotic cells. The liver epithelium exposed to aspartame and the extracts of S. gabonensis showed regenerating hepatocytes with many binucleated cells seen, few necrotic and apoptotic bodies also seen.

Conclusion: The significant decrease in liver injury biomarkers, increase in the oxidative stress biomarkers and the increased number of hepatocytes captured in the liver epithelium of animals co-administered S. gabonensis shows the novel property of S.gaboensis as an antioxidant defense against oxidative damage.