Sub-Cellular Correlation of Nitrite in Cassava (Manihot Esculenta Crantz) Leaves and Nitrosamine Toxicology in Wistar Rats

The aim of this study was to determine the nitrite levels in the sub-cellular fractions of cassava (Manihot esculenta crantz) leaves containing chloroplast, mitochondria and in the cytosol respectively and to their contribution in the causation of liver toxicity in rats exposed to N-nitrosamine precursors. The design of this experiment consisted of three animal groups. The first group was administered with dimethylamine hydrochloride plus sodium nitrite (DMA.HCL + NaNO2), the second group was administered with sodium nitrite (NaNO2) only and the third group (control) was given distilled water. The methods used included cell fractionation, tissue homogenization and centrifugation, spectrophotometric analysis, enzymatic determination and histopathology. Nitrite levels were estimated at 6.08 ± 0.92, 4.06 ± 1.65 and 1.29 ± 1.66μg/200g of cassava leaf tissue in chloroplasmic, mitochondrial and cytosolic sub-cellular fractions respectively. Both the NaNO2 dose regime and the combined dose of DMA.HCL and NaNO2, at P- value 0.05, caused significant increases in GGT, ALP, AST and ALT levels in serum. The histopathological study of the rat liver for DMA.HCL + NaNO2 administration showed severe portal and central venous congestion while the NaNO2 administration revealed a mild periportal cellular infiltration. This study shows that there is a correlation of nitrite in the chloroplast, mitochondria and cytosol sub-cellular fractions of cassava leaves and administration of nitrite dietary level in cassava leaves and dimethylamine hydrochloride produced acute synergistic toxicity in the liver

N-Nitrosation of dimethylamine hydrochloride and its toxicology in the wistar rats fed different levels of dietary protein

The present study investigated the in vivo and in vitro effects of orally administered sodium nitrite (NaNO2) and dimethylamine hydrochloride (DMA–HCL) on liver of rats fed ad libitum with high protein diet (64%), normal protein diet (27%) and low protein diet (3.5%). Thirty Male Wistar rats were divided into three groups and kept for four weeks. Group one was given high protein diet, group two was given a normal protein diet, group three was given low protein diet, all the groups were administered with 3mg NaNO2 and 20mg DMA-HCL/kg, using the application of spectrophotometric analysis, centrifugation, histolopathology, enzymatic as well as colorimetric methods. Liver function test, showed significant elevations (P < 0.05) in the AST, ALT, ALP and GGT activities in all the groups compared with the control animals. The histopathology examination exhibited periportal necrosis. Following UV exposure after in vitro incubation of rat liver microsomal plus soluble fraction with NaNO2 plus DMA-HCL, nitrite concentration in the rats fed high protein was highest 4.033 and 0.470 μg/ml, compared to the control rats which was 0.052 and 0.00192 μg/ml before and after UV irradiation. Nitrite loss was significant (p<0.05) before and after UV exposure in all the groups, indicating that the UV-light has degraded the nitrosamine precursors, thereby inhibiting possible nitrosation. The study has revealed that in rats, a high protein diet enhances N-Nitrosation of dimethylamine hydrochloride, liver derangement and the metabolisms in vivo and in vitro of the resultant compound