Effect of curcumin and quercetin on lysosomal enzyme activities in streptozotocin-induced diabetic rats

SummaryBackground & aimsDiabetes causes impairment of various enzyme activities in the physiological system, including lysosomal enzymes. The effect of feeding curcumin, quercetin and aminoguanidine on lysosomal enzyme activities viz., N-acetyl-β-d-glucosaminidase, β-d-glucuronidase, β-d-galactosidase and acid phosphatase were studied in different tissues of streptozotocin-induced diabetic rats.MethodRats were divided into four control groups and four diabetic groups. Experimental groups were fed with diet supplemented with curcumin (0.5%) or quercetin (0.1%) or aminoguanidine (0.05%). Lysosomal enzyme activities were determined in various tissues.ResultsThe specific activity of N-acetyl-β-d-glucosaminidase in liver of diabetic rats was decreased when compared to control rats and was ameliorated with curcumin and quercetin treatment by 67% and 78%, respectively. On the other hand, β-d-glucuronidase activity was higher in the brain of diabetic rats (0.90 ± 0.04 nmol/mg protein/min), when compared to control rats (0.45 ± 0.02 nmol/mg protein/min) and was decreased in curcumin (0.75 ± 0.05 nmol/mg protein/min) and quercetin (0.74 ± 0.11 nmol/mg protein/min) treated rats. β-d-galactosidase activity in spleen of curcumin and quercetin fed diabetic group rats was ameliorated by 68% and 58%, respectively, in comparison to diabetic rats. Acid phosphatase activity in diabetic rats decreased in testis when compared to control.ConclusionCurcumin and quercetin feeding modulated lysosomal enzyme activities in different tissues during diabetes and the effect was comparable to well-known anti-glycative agent - aminoguanidine.