Abstract

This study evaluated the effects of lead exposure on the histoarchitecture of kidney, assessed the effects of lead on the levels of creatinine, urea and albumin in the plasma and determined the effects of M. oleifera leaf extract (MOLE) on the histoarchitecture of kidney in Wistar rats after lead-induced kidney damage. This was with a view to providing information on the ameliorative effects of M. oleifera leaf extract on lead-induced kidney damage. Thirty adult male Wistar rats weighing 120 - 180 g were used for this study. Kidney damage was experimentally induced by daily administration of lead acetate (50 mg/kg/day) for a period of 14 days. The test groups were treated with the M. oleifera leaf extract (100 mg/kg/day) for 14 days. At the end of treatment period, the rats were sacrificed and their kidneys were excised for histological and histomorphometric studies. Markers of renal function were biochemically determined in the plasma using enzyme calorimetric assay kit. Histomorphological  examinations of the stained kidney sections revealed that 100 mg/kg of MOLE had no adverse effects on the kidney of group C rats as the morphology of kidney of the rats in this group were normal and comparable with that of groups A and B. However, deleterious effects such as distortion of Bowman’s capsule with diminished glomerular space, structural alteration of proximal and distal convoluted tubules were observed in the kidney of group D rats following lead-induced damage. Treatment with MOLE protected the kidneys of groups E and F rats from lead-induced damage as the renal morphology appeared normal. The results of biochemical analysis revealed a significant increase in the plasma level of urea (F=203.9, p = 0.0001),  and creatinine (F= 7.42, p = 0.0002), in group D rats (56.79 ± 0.06 g/l, 2.91 ± 0.07 mg/dl), respectively compared with groups A (14.02±1.53 g/l, 2.33 ± 0.06 mg/dl), B (50.44±1.75 g/l, 2.54 ± 0.06 mg/dl), C (58.91±2.95 g/ l, 2.42 ± 0.11 mg/dl), E (12.18±1.45 g/l, 2.45 ± 0.08 mg/dl) and F (7.48±1.00 g/l, 2.39 ± 0.08 mg/dl) respectively. This is an indication of impaired renal function. Also, the results of the histomorphometry analysis showed a significant decrease in the number of glomeruli  present in each photomicrograph and the diameter of the urinary space in group D  respectively compared with groups A, B, C, E and F. This study showed that treatment with Moringa oleifera prevented the toxicity brought about by lead exposure and this is evidenced by an enhancement in the glomerular morphology and clearly seen renal tubules. In conclusion, our findings suggest that Moringa oleifera leaf extract had ameliorative and protective properties on lead-induced kidney injury.