Modern pharmacological actions of Longan fruits and their usages in traditional herbal remedies
Mohamad Hesam Shahrajabian, Wenli Sun and QI Cheng
Longan is an ever green tree of the Sapindaceae family. Longman fruit is grown commercially in many countries like China, India, Thailand, Vietnam and etc. In China, import of the longan fruit has been increasing in recent years. Longan are demanded in the market in various types such as fresh, dried, frozen and processed. Twelve important compounds longan are (1) β-sitosterol, (2) 2-phenylethanol, (3) 2-methyl-1,10-undecanediol, (4) (24R)-6β-hydroxy-24-ethyl-cholest-4-en-3-one, (4) Oleanolic acid, (5) Pinoresinol, (7) Nicotinic acid, (8) 4-hydroxybenzoic acid, (9) β-daucosterol, (10) 1-O-methyl-D-myo-inositol, (11) Uracil, and (12) Adenosine. The most important antioxidant compounds extract from longan shell are isovanillin, scopoletin, quercetin, hyperin, astragalin, and β-phenylethyl alcohol. The longan is suitable for the tropical zone subtopics in heat season. The flesh fruit is much in juicy, low in acid, high in sugar. Longan fruit has high nutritional and medicinal values and its main functional metabolites include polysaccharides, flavonoids, alkaloids and carotenoids. The functional metabolites provide medicinal, anticancer and antiaging benefits to humans. Longan fruit is used for enhancing memory, promoting blood metabolism, relieving insomnia and preventing amnesia. Its secondary metabolic products have been also shown to have anti-oxidative, anti-obesity, anti-cancer, anti-tyrosinase and immunomodulatory activities. Both longan flowers (long yan hua) and fruit (long yan rou) are used in traditional Chinese medicine and herbal preparations, but the fruit is used much more frequently. Longan contains several vitamins and minerals, including iron, magnesium, phosphorus and potassium and large amounts of vitamins A and C. In traditional Chinese medicine, longan fruits are considered warm, sweet and astringent. Many parts of the plant are used medicinally including the fruit itself, and dried fruits, relieves anxiety. The leaves are cool the system, and the flowers and seeds aid the kidneys. The roots are used to treat diabetics and to treat gonorrhea. All in all, the most important health benefits of longan are skin care, anti-aging, boosts libido, anti-anxiety, treats insomnia, blood tonic, promotes weight loss, increases energy, controls blood pressure, neuroprotection, strengthens immunity, speeds-up healing, prevents chronic diseases, aids in digestion, improves memory, vision health, useful in treating snake bites, and appropriate in dental care. The obtained findings suggest potential of longan as superfruit and its extract as an additive in the food and pharmaceutical industries. The bioactive compounds and pharmaceutical characteristics of longan should be studied to cosmetic and pharmaceutical products in the future.