protective effect of co- supplementation of propolis and vitamin B6 against gentamicin induced nephrotoxicity on proximal tubules in albino rat

ABSTRACT

Thirty albino rats were used in this work. Rats were divided into five groups, six rats each. Sham control group [Group A] were injected intraperitoneaily, with 5ml of 0.9% NaCI for ten successive days. Gentamicin group [Group B] rats were injected with gentamicin, intraperitoneally, at a dose of 100 mg /kg/day for a period of 10 days. Gentamicin and Vit. B6 group [Group C] rats were injected with gentamicin in the same dose simultaneously with Vit. 36 [2.5 mg/Kg/ day] for ten successive days. Gentamicin and Propolis group [Group D] rats were intraperitoneally injected with same does of gentamicin and propolis 10% solution and given orally by gastric gavage in a dose of 100 mg/kg/day for ten days. Gentamicin, vitamin B6 and propolis group [Group E] rats were injected intraperitoneally with gentamicin, vitamin B6 with the same previous doses and propolis of the same dose orally for ten successive days. On the 11[th] day, the animals were sacrificed. Samples of blood were analyzed for blood urea and serum creatinine. Excised kidneys were fixed in 10% phosphate buffered formalin, dehydrated with ascending grades of ethanol, cleared and, then, embedded in paraffin. The paraffin embedded tissue was cut at 6 Um section and stained with haematoxyline and eosin stains. Small specimens of the kidneys were prepared for ultrathin sections and examined under electron microscope. Gentamicin administration produced a significant increase in serum creatinine [P < 0.001 Vs control] which was avoided by simultaneous vitamin B[6] and propolis treatment for 10 days [P < 0.001]. Vitamin B6 or propolis treatment reduced gentamicin induced elevation in serum creatinine, but still significant over than that of the control by day eleven. The re-suits of the blood urea nitrogen determination were similar. Light microscopic examination of the renal tissues from gentamicin treated rats revealed severe histopathological changes of the proximal convoluted tubules, whereas specimens obtained from group C, or Group D - treated rats revealed only mild changes. In group E rats treated with both vitamin B[6] and propolis, histological examination revealed a normal renal parenchymal picture without any sign of inflammatory or degenerative changes. This finding was further validated by electron microscopic examination. In electron microscopic examination, the cells of the proximal convoluted tubules from group B contained multiple large lysosomes, the mitochondria lost their cristae, some luminal microvilli were disrupted. The protective effect of vitamin B6 against gentamicin-induced nephrotoxicity was supported by electron microscopic examination. While vitamin B6 and propolis-treated rats showed milder histopathological findings similar to that of control. Proximal tubular epithelial cells were regaining normal structure. In a few areas, the tubular cells were lower with few organelles and rudimentary villi. There was little protection by propolis alone against the nephrotoxic effects of gentamicin treatment. The present study could conclude that co-administration of vitamin B6 and propolis has beneficial effects on renal preservation in gentamicin induced nephrotoxicity