Nephrotoxic potentials of Oxytenanthera abyssinca (Rhizomes) from crude oil polluted areas and non-polluted areas of South Eastern Nigeria

Abstract

Oxytenanthera abyssinica is a tropical drought resistant plant. Its rhizome had been wildly used in ethenomedicine for the treatment of dysentry, rheumatism, oedema and polyuria as well as for the management of diabetes. Rhizomes of O. abyssinica used for this study were sourced from Owerezukala Anambra State that has not experienced crude oil pollution and from Akirika community in Abia State that had experienced crude oil pollution. The aim of this study is to compare the nephrotoxic potentials of methanol extract of the rhizomes in order to ascertain the possible effects of crude oil spillage on bio lives of the two areas. After the extraction of the rhizomes of O. abyssinica with 80% methanol, the extracts from non- crude oil polluted area of Owerezukala (NCOPOAE) and crude oil polluted area of Akirika (COPOAE) were dried and stored in a freezer for further studies. Sub-chronic toxicity profile was evaluated using the effects of 100, 200, and 400 mg/kg b.w of the extracts on the albino rats for 28days. Kidney function tests were used for the evaluation of the integrity of the nephrocytes. Histopathology was done using standard method on kidney cells. Results showed LD50 of 5000 mg/kg and 3800mg/kg for NCOPOAE and COPOAE respectively. Exposure of rats to different doses of the extracts for 28days resulted to significant increases in kidney function test parameters with COPOAE showing more damage than NCOPOAE particularly at 200 and 400 mg/kg. This result could indicate kidney impairment. These results were confirmed by histoparthological assay, which revealed more damages in rats fed 200 and 400 mg/kg COPOAE than NCOPOAE. Histopathology of the kidney cells revealed different stages of necrotic and morphological damages at different concentrations of both extracts, changes being more in rats’ organs treated with COPOAE than NCOPAE. These results could indicate that NCOPOAE was less toxic than COPOAE from crude oil contaminated community and hence could be more beneficial in ethnomedicine.