Curcumin is the most active part the yellow Indian spice turmeric (Curcuma longa). These scientists studied its effect in kidney disease in rats. The rats served as a model of the kidney disease that occurs in humans with diabetes. The chemical streptozotocin was used to cause diabetes in Wistar rats. Then the rats were fed Curcumin (0.5%) for 8 weeks. Kidney damage was measured by the amount of proteins passed in the urine. Healthy kidneys do not pass proteins in the urine. They also looked at whether four enzymes that are part of the kidney leaked out into the urine. They measured activities of several key kidney enzymes. These included glucose-6-phosphate dehydrogenase, glucose-6-phosphatase, lactate dehydrogenase, aldose reductase, sorbitol dehydrogenase transaminases, and ATPases. They measured the ratio of polyunsaturated fatty acids to saturated fatty acids. This ratio reflects the health of the kidney membranes. Some of their results showed that curcumin lead to significant reduction in the kidney disease caused by diabetes in these rats. Beneficial conclusions were based on the amount of enzymes and protein in the urine, the activity of kidney ATPases and fatty acid composition of renal membranes. These findings agreed with what they saw when they looked at slices of the kidneys under the microscope. They believe that the improvements they found may have been due to curcumins lowering of blood cholesterol levels.