Flaxseed ameliorates interstitial nephritis in rat polycystic kidney disease
Flaxseed ameliorates interstitial nephritis in rat polycystic kidney disease
Year: 1999
Authors: Ogborn, M.R. Nitschmann, E. Weiler, H. Leswick, D. Bankovic-Calic, N.
Publication Name: Kidney International
Publication Details: Volume 55; Pages 417-423.
Abstract:
Flaxseed has demonstrated useful anti-inflammatory properties in a number of animal models and human diseases. We undertook a study to determine if flaxseed would also modify clinical course and renal pathology in the Han: SPRD-cy rat. Male Han: SPRD-cy rats were pair fed a 10% flaxseed or control rat chow diet for eight weeks from weaning. Tissue was harvested for analysis of cystic change, apoptosis, cell proliferation, and fibrosis. Tissue was also harvested for lipid analysis using gas chromatography. Animals thrived on both diets. Flaxseed-fed animals had lower scrum creatinine (69 vs. 81 mol/liter, P = 0.02), less cystic change (1.78 vs. 2.03 ml/kg, P = 0.02), less renal fibrosis (0.60 vs. 0.93 ml/kg, P = 0.0009), and less macrophage infiltration (13.8 vs. 16.7 cells/high-power video field) of the renal interstitium than controls. The groups did not differ in renal tubular epithelial cell apoptosis and proliferation. Lipid analysis revealed significant renal enrichment of 18 and 20 carbon w3 polyunsaturated fatty acids (total w6:w3 ratio 3.6 vs. 9.1, P < 0.0001). Flaxseed ameliorates Han:SPRD-cy rat polycystic kidney disease through moderation of the associated chronic interstitial mephritis. The diet alters renal content of polyunsaturated fatty acids in a manner that may promote the formation of less inflammatory classes of renal prostanoids. (Author's abstract)
The Han:SPRD-cy rat is a model of polycystic kidney disease (PKD) that shares autosomal dominant inheritance, progression through early adult life, and sexual dimorphism with human disease. Flaxseed has shown beneficial results in other forms of renal injury and thus this study was undertaken to test the hypothesis that dietary flaxseed supplementation would modify the clinical course and renal pathology of male Han:SPRD-cy rats. The benefit of flaxseed products has been demonstrated in human and murine systemic lupus erythematosus, experimental models of mammary and colonic cancer, hypercholesterolemia, and glomerulosclerosis induced by renal ablation. The results of this study indicate that the potential beneficial influence of flaxseed dietary substitution on inflammatory disease extends to the renal tubule interstitium. This study suggest that flaxseed supplementation may substantially alter the PUFA content of the kidney. The lignan content of flaxseed may be in part responsible for these results. The lignans enterodiol and enterolactone may have estrogenic, anti-estrogenic, and platelet-aggregating factor activity. Gender is a significant factor in the progression of both animal and human PKD. Estrogen-like compounds may influence inflammatory activity through the monocyte chemo-attractant protein (MCP-1) pathway. The authors conclude that flaxseed may represent a practical dietary therapy in renal disease.
