Effect of Alstonia boonei and Morinda lucida on Renal Histology of Wistar Rats Infected with Trypanosoma brucei brucei

Abstract

Animal African trypanosomiasis is a protozoan disease caused by trypanosomes and transmitted through the bite of an infected tsetse fly. The disease has an adverse effect to the economy of the affected areas and drugs used for the treatment of the disease are faced with several challenges ranging from resistance to the parasite to high level of toxicity. Our study aimed at evaluating the effect of Alstonia boonei and Morinda lucida plant extracts on the renal histology of wistar rats infected with Trypanosoma brucei brucei. Phytochemical screening of the methanol extracts indicated the presence of alkaloids, saponins, tannins, flavonoids, carbohydrates, phenols and steroids/terpenes, while glycosides were not detected. Only four of the eight constituents tested for were detected in the chloroform leaf extract of A. boonei, namely, alkaloids, tannins, flavonoids, and carbohydrates. Alkaloids, tannins falvonoids, and carbohydratses were detected in both the chloroform and methanol extract of Morinda lucida. Histological lesions of the infected-untreated rats revealed severe cellular degeneration in the renal cortex of T. brucei infected rats. Furthermore, the glomerular tufts were shrunken leaving a large Bowman’s. The renal photomicrographs of rat treated with 500mg/kgbwt of Alstonia boonei revealed that the renal cortex presented apparently normal histological features of Malpighian renal corpuscle containing glomerulus and Bowman’s space with slightly shrunken glomerulus. The proximal convoluted tubules had narrow lumina and were lined with cuboidal cells with rounded vesicular basal nuclei. Groups treated with 1000mg/kgbwt revealed erythrocytic remains of degenerated renal cells with scanty inflammatory cells in the cortical region of kidney of the wistar rats. However, the glomerulus, the proximal and distal convoluted tubules presented normal histological features. The results indicated that treatment with graded doses of methanol extract of A. boonei elicited varying effects on the visceral organs of the infected animals. It was noted that Alstonia boonei ameliorated the effect of the infection on the kidney of the infected animals with the histology sections being comparable with those treated with the reference anti-trypanosomal drug (Diminazine aceturate) and the uninfected rats. However, Morinda lucida had little or no ameliorative effect on the kidney of wistar rats infected. Therefore, we recommend that extracts of Astonia boonei should be characterized and active components responsible for the ameliorative effect be detected and elucidated structurally.