Uses of Luo Han Guo
In southern China, luo han guo is popularly considered a longevity aid and is used to balance heat buildup caused by internal conditions, life-forces, or external heat. It is used as an expectorant and antitussive to treat lung congestion, cough, other respiratory ailments, and sore throat. It also is used for constipation and chronic enteritis. Luo han guo is a low-caloric, low-glycemic food used as a sweetener in beverages and cooked food.
Botany
Luo han guo refers to the fruit of S. grosvenori , a perennial, dioecious, herbaceous climbing vine, 2 to 5 m in length. It is cultivated in southern China, mainly in the Guangxi, Guangdong, Guizhou, Hunan, and Jiangxi provinces, with most of the product from the mountains of Guilin. The round, green fruit turns brown when dried and is covered with small hairs. This is a distinct plant from bitter melon, Momordica charantia .
History
Luo han guo has been used for centuries in China and in Southeast Asia for its sweet flavor and medicinal properties. Historic writings record Song Dynasty monks brewing it as a medicinal beverage more than 800 years ago. The dried fruit has been used as an ingredient in soup or stew to prevent symptoms of long-term conditions or for ongoing treatment. It is used as a tea for immediate relief of discomfort.
Hypoglycemic
In addition to its natural sweetening characteristic, luo han guo has exhibited antihyperglycemic effects. In rats, crude extracts of S. grosvenori and the triterpene glycosides inhibited a rise in postprandial blood glucose levels when given orally 3 minutes prior to oral administration of maltose. The suggested antihyperglycemic effect was via the inhibition of maltase.
Antioxidant
S. grosvenori extract and the cucurbitane glycosides mogroside IV, mogroside V, 11-oxo-mogroside V, and siamenoside I inhibited copper-mediated, low-density, lipoprotein and cell-mediated, low-density lipoprotein oxidation in a dose-dependent fashion, with 11-oxo-mogroside V as the most active component. The antioxidant, free-radical scavenging activities of the extract and 11-oxo-mogroside V were less than those of vitamin E in the same in vivo study.
