Effects of Solanum malacoxylon on duodenal calcium binding protein in the diabetic rat.

Duodenal calcium absorption and calcium binding protein (CaBP) are depressed in uncontrolled experimental (alloxan and streptozotocin) diabeties in the rat. Administration of an aqueous extract of the South American plant Solanum malacoxylon to diabetic rats restores duodenal calcium absorption to control levels. Since CaBP is thought to play a role in intestinal calcium transport, we isolated CaBP from duodenal mucosa of control, diabetic, and S. malacoxylon-treated diabetic rats. CaBP, whose concentration is about half normal in mucosal extracts from diabetic rats by treatment of diabetics with Smalacoxylon extracts. Hence these studies provide a further correlation between duodenal calcium absorption and levels of duodenal CaBP. In addition, a new purification procedure is described which produces a 17-fold increase in purity of CaBP above that attainable by our previously reported method.