This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Java Plum, Eugenia Jambolana. The bark and seed are official in the Netherlands; the seed in most cases is preferred. This drug is designated as Syzygium Jambolanum in Homeopathic textbooks. It has long been used in India.
The contention is made that it inhibits diastasic fermentation and "increases renal blood-pressure." How it would do this without increasing pressure at large does not appear. Ten-grain doses of the powdered seeds three times a day have been used in the treatment of diabetes mellitus. Tinctures, fluidextracts, and proprietary products are on the market. I have never given the drug adequate test, have seen little convincing literature, and give the above merely as a record of claims made.