First of all, the lychee nut that we are going to talk about next refers to the real nut instead of the dried lychee fruits as you might think. Medicinally it is better known as Li Zhi He. As everyone knows, fresh lychees fruit is juicy and sweet. But do you know that litchi nuts, the thing you will typically throw away after enjoying its delicate and whitish pulp, is also a Chinese herb that is of great use to a lot of patients? Are lychee nuts good for you? As a matter of fact, clinically it is frequently used in many formulas for the treatment of colic, diabetes, testicular pain and various types of pain. So, next time don’t throw it in trash bin easily and try to make full use of it because it can do good to you.
What is lychee nut?
Just as its name indicates, it refers to the mature seeds of Litchi chinensis Sonn., which is the only member of the genus Litchi in the soapberry family, namely Sapindaceae. And it has got a few different names, such as Leechee Nut, Semen Litchi, Litchi Semen, Lychee Seed, litchi nuts, lichee nut, and so on. In China lychee tree is mainly cultivated in Fujian, Guangdong, Guangxi and other provinces. The ripe fruits are usually picked in summer. And then remove the peel and fleshy aril, wash, and dry in the sun. It is used raw or processed by brine. And it needs to be smashed before the use.
Lychee nut tree is an evergreen tree, 10 to 15 meters high. Evenpinnate leaf is alternate. The length of leaves and handle is 10 to 25cm; leaflets are 2 or3 pairs and with 7 to 8cm long small petiole; blade is lanceolate or ovate-lanceolate, 6 to 15cm long, 2 to 4cm wide, glabrous, thinly leathery or leathery, and with abruptly acuminate or caudate-acuminate apex, and entire margin. Panicle is acrogenous, wide, multi-branched; flowers bloom in spring, monoecious, small, and covered with short down. Fruit is nearly spherical and looks like drupe. Rind is hard, thin, dark red when ripe, and with strumaes. Seeds are brown. Its flowering time is from February to March and the fruit time is from June to July.
Seeds contain 1.12% saponin, 3.43% tannins, and α-methylene cyclopropylglycine. And traces of volatile oil have been isolated. And volatile oil includes 3-acetoin, 2,3-butanediol, copaene, cis-caryophyllene, humulene, ledol, and so on.
Lychee nut health benefit
As one of very common summer fruits, lychee fruits are known as one of the Four Southern Fruits, in which other three are along with banana, pineapple, and longan. Needless to say, nothing beats lychee when it comes to pleasing your taste buds. What’s more, the dried lychee nuts are also a good medicine, which has been recorded in Chinese Pharmacopoeia. Modern pharmacological studies have shown that this herb can lower lipid, reduce blood glucose, fight tumor, inhibit hepatitis B surface antigen, prevent platelet aggregation, and more.
Modern pharmacological actions of lychee nuts
1. The α-methylene cyclopropylglycine contained has hypoglycemic effect when injected to mice;
2. Its water extract or alcohol extract and lychee seed oil can regulate lipids and resist oxidation. Hence, it can reduce serum total cholesterol (TC) and triglycerides (TC);
3. It can resist ALX-induced free radical damage and enhance the activity of antioxidant enzyme SOD;
4. It antagonizes the mutagenic effects of salmonella typhimurium;
5. Its water extract has inhibition on hepatitis B virus surface antigen.
Selected lychee nut recipes in herbal remedies
From the point of view of TCM (traditional Chinese medicine), this herb is sweet and slightly bitter in flavor and warm in medicinal properties and covers meridians of liver, kidney, and spleen. Common functions include regulating qi to alleviate pain and dispelling cold to remove stagnation. Prime lychee nut uses are hernia, testicular swelling and pain, epigastric pain, dysmenorrhea, and postpartum abdominal pain. Recommended dosage is from 6 to 10 grams in decoction and from 1.5 to 3 grams in powder or pills.
1. Li Xiang San from Jing Yue Quan Shu (Jingyue’s Collected Writings). In this formula it couples with Mu Xiang (Radix Aucklandiae) for the treatment of recrudescent pain in heart, abdomen, and gastral cavity.
2. Li He San from Shi Yi De Xiao Fang (Effective Prescriptions of Well Known Doctors). In this prescription it joins hand with Hui Xiang ( Fructus Foeniculi) and Qing Pi (Pericarpium Citri Reticulatae Viridae) to treat kidney that is as big as a bucket.
3. Yu Huan Lai Fu Dan from Tan Xiao Jie Xiao Fang (All Efficacious Prescriptions From Tan’xian). In this recipe it combines with Chen Pi (Citrus peel) and Liu Huang (Sulphur) to cure hernia.
4. Juan Tong San from Fu Ren Liang Fang (Excellent Prescriptions for Gynecology). This herb is used along with Xiang Fu Zi (Cyperus rotundus rhizome) to relieve the blood-qi stabbing pain.
Lychee nuts side effects and contraindications
Leechee nuts have been proved with very low toxicity by the acute toxic test, in which the mice were fed with a dose of 20g/kg but none died within 3 days. According to the Ben Cao Cong Xin (Thoroughly Revised Materia Medica), Li Zhi He shouldn’t be used in the patients who have no cold, dampness, and stagnated qi.