AbstractThe basis for the antihyperglycaemic property ofIndigofera arrecta, a plant used for the treatment of diabetes, was evaluated using normoglycemic and streptozotocin‐induced diabetic rats. The rats were given different doses of the freeze‐dried extract of the plant material orally and intraperitoneally. The extract decreased the plasma glucose levels of fasting normoglycemic rats, but did not prevent the rise in plasma glucose after an oral glucose load in these rats. The extract increased plasma insulin levels. In the diabetic rats, the rise in blood glucose after an oral glucose load was not affected when the extract was administered 17 days after induction of diabetes. When administered 7 days after induction of diabetes, the rise in blood glucose was decreased, and was stabilized after 30 min. The results indicate thatI. arrectais insulinotropic, requiring functional beta cells to express its eff