It was long time ago. There was an evil dragon in Fu Jiang province. Every August this dragon brought hurricanes to the area to destroy crops, collapse the houses, kill people and animals. Local people had to leave their home and hide in caves. A young guy called Gui Yuan who was good at Martial arts decided to fight and get rid of the evil dragon. In the August, the dragon with the hurricanes arrived. Gui Yuan gave it pork and lamb marinated with alcohol which made its mouth-watering. It ate all the food in a second and lay down and fall sleep. Gui Yuan stabbed the its left eye and took the eyeball out. It rolled with extreme pain and wanted to escape. Gui Yuan grabbed its dragon horns, rode on it, and took its right eyes out. The dragon screamed with pain and died, however Gui Yuan was injured badly during the fight and sadly died as well. He was buried with the dragoneyes. Hereafter, a tree grew there, and its fruits were like dragon eyes which were called Long Yan which means dragon eyes. These fruits were also called Gui Yuan in memory of the hero Gui Yuan.
Longan fruits are widely distributed in Southeast Asia, such as South China, (Fu Jian province is number one producer in China), Taiwan, Vietnam, and Thailand. Longan fruits are sweet in taste and warm in nature. Their white arils are delicious and edible and full of nutrition, such as vitamins A and C, amino acids, and minerals including iron and magnesium, fibers etc. They are attributed to heart and spleen meridians. Longan fruits can be used as Chinese herbal medicine. Daily dosage is 9-15g. They replenish heart and spleen, nourish blood and sooth nerves.
Their modern pharmacological effects include:
1, Calming the nerves with neuroprotection, relieving anxiety and insomnia, improving nerve pain and swelling.
2, antioxidant effects, antiaging, boosting energy, improving memory,
3, immunomodulatory effects and strengthening immunity
4, others: such as anti-diabetes, skin care, anticancer, promoting blood metabolism to tonic blood, help vision etc.
Xiang-rong Zhu J Zhejiang Univ Sci B. 2019 Jun; 20(6): 503–512.