Effect of essential oil of onion (allyl propyl disulphide) on blood glucose, free fatty acid and insulin levels of normal subjects.

The administration of allyl propyl disulphide (APDS), a volatile substance contained in onion, to six normal volunteers after a 12 hour fast caused a significant fall in the blood glucose levels and a significant rise in the serum insulin levels during the subsequent 4 hours. It is argued that this effect is due to an insulin sparing action. The expected rise of serum free fatty acid levels after fasting did not occur after APDS administration and this effect is probably related to the simultaneous rise in the insulin levels.