ABSTRACT
Experimental induction of hyperoxaluria by ethylene glycol (EG) administration is disapproved as it causes metabolic acidosis while the oral administration of chemically synthesized potassium oxalate (KOx) diet does not mimic our natural system. Since existing models comprise limitations, this study is aimed to develop an improved model for the induction of dietary hyperoxaluria, and nephrocalcinosis in experimental rats by administration of naturally available oxalate rich diet. Male albino Wistar rats were divided into five groups. Group I, control; group II rats received 0.75% EG, group III rats fed with 5% KOx diet and group IV and V rats were administered with spinach extract of 250 and 500 mg soluble oxalate/day respectively, for 28 d. Urine and serum biochemistry were analyzed. After the experimental period, rats were sacrificed, liver and kidney tissue homogenates were used for antioxidant and lipid peroxidation assay. Relative change in expression of kidney injury molecule-1 (KIM-1) and crystal modulators genes in kidney tissues were evaluated. Tissue damage was assessed by histology studies of liver and kidney. Experimental group rats developed hyperoxaluria and crystalluria. Urine parameters, serum biochemistry, antioxidant profile, lipid peroxidation levels and gene expression analysis of experimental group II and III rats reflected acute kidney damage compared to group V rats. Histopathology results showed moderate hyperplasia in liver and severe interstitial inflammation in kidneys of group II and III than group V rats. Ingestion of naturally available oxalate enriched spinach extract successfully induced dietary hyperoxaluria and nephrocalcinosis in rats with minimal kidney damage.
Subject(s)
Disease Models, Animal , Foodborne Diseases/etiology , Hyperoxaluria/etiology , Nephrocalcinosis/etiology , Oxalic Acid/poisoning , Plant Leaves/adverse effects , Spinacia oleracea/adverse effects , Administration, Oral , Animals , Biomarkers/blood , Biomarkers/metabolism , Biomarkers/urine , Crystallization , Ethylene Glycol/toxicity , Foodborne Diseases/metabolism , Foodborne Diseases/pathology , Foodborne Diseases/physiopathology , Gene Expression Regulation/drug effects , Hyperoxaluria/metabolism , Hyperoxaluria/pathology , Hyperoxaluria/physiopathology , Kidney/drug effects , Kidney/metabolism , Kidney/pathology , Lipid Peroxidation/drug effects , Liver/drug effects , Liver/metabolism , Liver/pathology , Male , Nephrocalcinosis/metabolism , Nephrocalcinosis/pathology , Nephrocalcinosis/physiopathology , Oxalic Acid/administration & dosage , Oxalic Acid/chemistry , Oxalic Acid/metabolism , Plant Extracts/adverse effects , Plant Extracts/chemistry , Plant Leaves/chemistry , Rats, Wistar , Renal Insufficiency/etiology , Spinacia oleracea/chemistryABSTRACT
Oxalates stimulate alterations in renal epithelial cells and thereby induce calcium oxalate (CaOx) stone formation. Bacillus subtilis YvrK gene encodes for oxalate decarboxylase (OxdC) which degrades oxalate to formate and CO2. The present work is aimed to clone the oxdC gene in a mammalian expression vector pcDNA and transfect into Human Embryonic Kidney 293 (HEK293) cells and evaluate the oxdC expression, cell survival rate and oxalate degrading efficiency. The results indicate cell survival rate of HEK293/pcDNAOXDC cells pre-incubated with oxalate was enhanced by 28%. HEK293/pcDNAOXDC cells expressing OxdC treated with oxalate, significantly restored antioxidant activity, mitochondrial membrane potential and intracellular reactive oxygen species (ROS) generation compared with HEK293/pcDNA. Apoptotic marker caspase 3 downregulation illustrates HEK293/pcDNAOXDC cells were able to survive under oxalate-mediated oxidative stress. The findings suggest HEK293 cells expressing oxdC capable of degrading oxalate protect cells from oxidative damage and thus serve as a therapeutic option for prevention of CaOx stone disease. [Formula: see text].
