Luo Han Guo is a commonly used herbal remedy for relieving coughs and alleviating wheezing. It is the dried fruit of Siraitia grosvenorii (Swingle) C.Jeffrey ex A.M.Lu et Z.Y.Zhang, a plant in the Cucurbitaceae family. It has the effects of clearing heat and moistening the lungs, soothing the throat and restoring the voice, and moistening the intestines to relieve constipation. It is primarily used to treat dry coughs caused by lung heat, sore throat with loss of voice, and constipation due to intestinal dryness.
Luohan Fruit
Luo Han Guo is a commonly used herbal remedy for relieving coughs and alleviating wheezing. It is the dried fruit of Siraitia grosvenorii (Swingle) C.Jeffrey ex A.M.Lu et Z.Y.Zhang, a plant in the Cucurbitaceae family. It has the effects of clearing heat and moistening the lungs, soothing the throat and restoring the voice, and moistening the intestines to relieve constipation. It is primarily used to treat dry coughs caused by lung heat, sore throat with loss of voice, and constipation due to intestinal dryness.
Chinese Name : 罗汉果
Latin Name : Siraitiae Fructus
Aliases : Lahan Fruit, False Bitter Melon, Smooth-fruited Wood Turtle, Golden Unchangeable, Luohanpei, Naked Turtle
Authentic Producing Area : Mainly produced in Guangxi
Nature, Flavor & Meridian Tropism : Sweet in taste, cool in nature; enters the Lung and Large Intestine meridians
Benefits & Efficacy
Benefits
This product has the effects of clearing heat and moistening the lungs, soothing the throat and restoring the voice, and moistening the intestines to relieve constipation.
Indications
It is primarily used to treat dry cough due to lung heat, sore throat with loss of voice, and constipation due to intestinal dryness.
Usage and Dosage
Oral use: Decoct 9–15 g; or steep in boiling water and drink.
Precautions
1. Contraindicated for those allergic to this product; use with caution if you have a history of allergies. 2. While taking Luo Han Guo, avoid smoking, alcohol, and spicy, raw, cold, greasy, fried, or other irritating foods. 3. Luo Han Guo is primarily indicated for coughs caused by lung heat. For those with coughs caused by wind-cold, taking Luo Han Guo may exacerbate the condition, as its cooling nature may suppress the body’s yang energy, hindering the expulsion of wind-cold pathogens.
Chemical Constituents
The fruit primarily contains triterpenoid glycosides, including semengoside I, luohangoside IIE, III, V, VI,luohanguo-neoside, as well as the flavonoids kaempferol-3,7-α-L-rhamnoside and luohanguo-flavone D-mannitol. It also contains large amounts of glucose and fructose, as well as more than 20 inorganic elements such as manganese, iron, and nickel, along with protein and vitamins C and E.The seeds contain oils, including fatty acids such as linoleic acid, oleic acid, and palmitic acid.
Pharmacological Actions
This product has antitussive, expectorant, laxative, immune-boosting, hypoglycemic, hepatoprotective, and antioxidant effects.
Relevant Discussions
*Lingnan Caoyaolu* states: “Treats coughs caused by phlegm-fire.”
Applications
Clinical Applications
1. To treat phlegm-related coughs and wheezing, it can be decocted and taken alone or combined with Stemona tuberosa and white mulberry bark.
2. To treat constipation due to intestinal dryness, steep it in honey and drink the infusion.
Related Compatibility
1. Luo Han Guo Combined with Mulberry Bark: Luo Han Guo is sweet, cool, and light in nature, excelling at clearing lung heat, resolving phlegm, soothing the throat, and relieving pain; Mulberry Bark is sweet, cold, and descending in nature, particularly effective at purging lung heat, relieving wheezing, promoting diuresis, and reducing swelling. When used together, these two herbs work to clear and purge lung heat, relieve coughing, and resolve phlegm. Suitable for coughing and wheezing due to lung heat, accompanied by thick, yellow phlegm.
2. Luo Han Guo Combined with Honey: Luo Han Guo is sweet, cool, and light in nature; it also promotes fluid production, moistens the intestines, and relieves constipation. Honey is sweet and neutral in nature, and is effective in moistening the intestines and relieving constipation. When used together, these two herbs enhance the effect of moistening the intestines and relieving constipation. This combination is suitable for constipation caused by intestinal dryness.
Medicinal Identification
Luo Han Guo and Pang Da Hai: Both can clear lung heat, resolve phlegm, soothe the throat, relieve pain, and moisten the intestines to promote bowel movements. They are both effective for treating lung heat with phlegm-induced cough, sore throat, and constipation caused by external pathogens or internal imbalances.However, Pangda Hai is sweet, cold, and light in nature; it excels at clearing and dispersing lung qi, resolving phlegm, soothing the throat, and restoring the voice, while also clearing and purging fire and heat. It is particularly used for hoarseness due to lung heat, constipation caused by dry heat, and headaches with red eyes. Luo Han Guo is sweet and cool in nature; it excels at clearing lung heat, resolving phlegm and fluid retention, and promoting the production of body fluids. It is especially suitable for those with cough, wheezing, sore throat, and constipation due to intestinal dryness.
Related Medicines
1. Chuanbei Luohan Cough-Relief Granules (from *Pharmaceutical Standards of the Ministry of Health of the People’s Republic of China: Traditional Chinese Medicine Formulated Preparations*)
(1) Composition: Sichuan fritillary bulb, loquat leaf, platycodon root, menthol, luohan fruit.
(2) Functions and Indications: Clears the lungs, relieves cough, and eliminates phlegm. Used for bronchitis and coughs associated with the common cold.
2. Luo Han Guo and Yuzhu Granules (2020 Edition of *Clinical Guidelines for Traditional Chinese Medicine Formulations*)
(1) Composition: Luo Han Guo, Yuzhu.
(2) Functions and Indications: Nourishes yin, generates body fluids, moistens the lungs, and relieves cough. Used for dry coughs and dry, sore throat.
3. Luo Han Guo Cough Syrup (from *Pharmaceutical Standards of the Ministry of Health of the People’s Republic of China: Traditional Chinese Medicine Formulated Preparations*)
(1) Composition: Luo Han Guo, loquat leaf, mulberry bark, white front, stemona, platycodon, peppermint oil.
(2) Functions and Indications: Expels phlegm and relieves cough. Used for coughs associated with the common cold and bronchitis.
Medicinal Diet Therapy
1. Monk Fruit Braised Rabbit
(1) Benefits: Moistens the lungs, relieves cough, and promotes skin health. Suitable for conditions such as dry cough due to lung heat, dry skin, and a dull complexion.
(2) Ingredients: 1 monk fruit, 300g rabbit meat, 10g lettuce, 10g each of cooking wine, ginger, scallions, and soy sauce, 4g salt, 3g MSG, 300g fresh broth,50g vegetable oil.
(3) Preparation: Wash the luohan fruit and split it open. Wash the rabbit meat and cut it into 3-centimeter squares. Peel the lettuce and cut it into 3-centimeter squares. Slice the ginger and cut the scallions into sections. Heat a wok over high heat. When the vegetable oil reaches 60% heat, add the ginger and scallions and stir-fry until fragrant. Then add the rabbit meat, luohan fruit, lettuce,cooking wine, soy sauce, white sugar, salt, MSG, and the broth. Simmer until cooked through.
2. Luo Han Guo and Lean Pork Soup
(1) Benefits: Relieves pain and reduces inflammation; alleviates dry throat and sore throat; also helps improve the physical condition of asthma patients.
(2) Ingredients: 1 Luo Han Guo, 250 grams of lean pork.
(3)Instructions: Wash and slice the lean pork, then blanch in boiling water for about 2 minutes; remove and set aside. Tear the luohan fruit into pieces and wash thoroughly. Pour 5 bowls of water into a pot and bring to a boil. Add the pork slices and luohan fruit, cover the pot, and steam in a steamer for about 2 hours.
3. Loquat and Luohan Fruit Porridge
(1) Benefits: Soothes the throat and disperses nodules.Suitable for children with chronic pharyngitis.
(2) Ingredients: 15 grams of loquat leaves, 1 luo han guo, 30 grams of japonica rice, and rock sugar to taste.
(3) Preparation: Finely chop the loquat leaves and wrap them in cheesecloth. Chop the luo han guo and place it in a pot with the japonica rice. Add an appropriate amount of water and cook into a thin porridge. Then add rock sugar to taste.
Notes
Patients requiring treatment with traditional Chinese medicine should first consult a licensed TCM hospital, where a TCM practitioner will conduct a professional pattern differentiation and issue a prescription.
Processing & Preparation
Harvesting & Processing
Harvest when the fruit ripens in autumn; dry over a fire, brush off the fuzz, and use raw.
Processing Methods
Take the raw herbal material and remove impurities. Crush before use.
Storage Methods
Store in a dry container in a well-ventilated, dry place.
Crude Drug Identification
Identification
1. The powder of this product is brownish-yellow. Most of the fruit peel stone cells occur in clusters; they are yellow, square, or oval, 7–38 μm in diameter, with thick walls and distinct pits and grooves. Seed coat stone cells are oblong or irregular in shape, with thin walls and pits. Fibers are long fusiform, 16–42 μm in diameter, with relatively large cell cavities and distinct pits in the walls.Vessels with ladder-like and spiral patterns are visible. Parenchymatous cells are irregular in shape and possess pits.
2. Take 2 g of the powdered sample, add 20 mL of dilute ethanol, heat and reflux for 30 minutes, filter, and evaporate the filtrate to approximately 5 mL. Extract twice with n-butanol (10 mL and 5 mL), combine the n-butanol extracts, and evaporate to dryness. Dissolve the residue in 1 mL of methanol to prepare the test solution.Separately, take 1 g of Luo Han Guo reference herbal material and prepare a reference herbal material solution using the same method. Then, take the Luo Han Guo saponin V reference standard, dissolve it in methanol to prepare a solution containing 1 mg per mL, and use this as the reference standard solution.Perform the test according to the thin-layer chromatography method (General Chapter 0502). Pipette 5 μL of each of the three solutions mentioned above and apply them separately onto the same silica gel G thin-layer plate. Develop the plate using n-butanol–ethanol–water (8:2:3) as the developing solvent, remove the plate, allow it to air-dry, and spray it with a 10% ethanol solution of sulfuric acid containing 2% vanillin. Heat until the spots become clearly visible.In the chromatogram of the test sample, spots of the same color appear at positions corresponding to those in the chromatograms of the reference herbal material and the reference standard.
Properties of Crude Drugs
This product is ovate, elliptical, or spherical, 4.5–8.5 cm long and 3.5–6 cm in diameter. The surface is brown, yellowish-brown, or greenish-brown, with dark patches and yellow pubescence; some specimens bear 6–11 longitudinal striations.The apex bears a scar from the style, and the base bears a scar from the fruit stalk. The fruit is light in weight, brittle in texture, and has a thin pericarp that breaks easily. The mesocarp (middle and inner pericarp) is spongy and light brown. The seeds are flattened and round, numerous, approximately 1.5 cm long and 1.2 cm wide; they range in color from light red to reddish-brown, with a slight depression in the center on both sides, radial grooves around the periphery, and grooves along the edges. It has a faint odor and a sweet taste.
Properties of Processed Slices
This product is ovate, elliptical, or spherical. The surface is brown, yellowish-brown, or greenish-brown, with dark spots and yellow pubescence, and features radial longitudinal striations. It is light in weight, brittle in texture, with a thin pericarp that breaks easily. The pulp (middle and inner pericarp) is spongy and light brown.The seeds are flattened and round, occurring in large numbers; they range in color from light red to reddish-brown, with a slight depression in the center on both sides, radial grooves around the periphery, and grooves along the edges. They have a faint odor and a sweet taste.
Botanical Information
Botanical Classification
Luohan fruit (Luohan guo), a plant of the genus Luohan in the Cucurbitaceae family.
Morphological Characteristics
A perennial climbing herb. It has a swollen tuberous root that is spindle-shaped or nearly spherical. The stem is somewhat stout, with ridges and grooves; initially covered with yellowish-brown soft hairs and black wart-like glandular scales, but the hairs gradually fall off or the stem becomes glabrous. Petioles are 3–10 cm long, covered with the same type of hairs and glandular scales as the branches;the leaf blade is membranous, ovate-cordate, triangular-ovate, or broadly ovate-cordate, 12–23 cm long and 5–17 cm wide, with an acuminate or long-acuminate apex, slightly wavy margins, and small teeth formed by protruding minor veins; it is ciliate along the margins, green on one side and covered with sparse soft hairs and black wart-like glandular scales, which gradually fall off with age, leaving the surface nearly glabrous;the underside is pale green, covered with short hairs and interspersed with black wart-like glandular scales, which gradually fall off with age. The tendrils are somewhat stout, initially covered with short soft hairs but gradually becoming glabrous; they are dichotomous and spiral on both the upper and lower surfaces at the bifurcation point. The species is dioecious; the male inflorescence is racemose, with 6–10 flowers borne on the upper part of the rachis, which is also covered with short soft hairs and black wart-like glandular scales;the pedicels are slender; the calyx tube is ring-shaped, often bearing three oblong membranous scales at the throat; the calyx lobes number five, are triangular, with a drill-like tail at the apex, and bear three veins that are slightly raised; the corolla is yellow, covered with black glandular dots; the lobes number five, are oblong, and often bear five veins; the stamens number five and are inserted below the tube near the base;with two fused at the base and one free, filaments swollen at the base;Female flowers are solitary or clustered in groups of 2–5 at the tip of a 6–8 cm peduncle; both the calyx and pedicel are larger than those of the male flowers; there are 5 rudimentary stamens; the ovary is oblong, 10–12 mm long, densely covered with yellowish-brown tomentum; the style is short and stout; the stigma is tripartite, swollen, sickle-shaped, and bifid.The fruit is spherical or oblong, 6–11 cm long and 4–8 cm in diameter, initially densely covered with yellowish-brown tomentum; the pericarp is relatively thin and becomes brittle when dry.Seeds are numerous, pale yellow, nearly round or broadly ovate, flattened, 15–18 mm long, 10–12 mm wide, with a bluntly rounded base and a slightly narrowed apex; both surfaces are slightly concave in the middle, surrounded by radial grooves, and the margins are slightly wavy; they are deep reddish-brown when young and lighten in color upon maturity. Flowering occurs from February to May, and fruiting from July to September.
Distribution Area
It is distributed in Jiangxi, Hunan, Guangdong, Guangxi, Guizhou, and other regions; in some parts of Guangxi, it is already cultivated as an important cash crop.
Growth Habits
Luo Han Guo prefers a warm, cool, and foggy climate and a partially shaded environment. It is not particularly demanding regarding soil, but thrives best in deep, loose, fertile, well-drained loam rich in humus. It is not suitable for cultivation in dry, barren, low-lying areas with poor drainage or in saline-alkali soils.The underground tubers begin to sprout around the Qingming Festival, when temperatures rise above 15°C, and tender shoots begin to emerge between the Grain Rain and Start of Summer solar terms. When the vines reach a length of about 60 cm, they begin to produce lateral shoots and develop tendrils. The optimal growth temperature is around 25°C; when temperatures fall below 15°C, plant growth ceases and the plants gradually wither.Luohan fruit is a dioecious plant, and its pollen is sticky, making wind and insect pollination difficult; artificial pollination is essential for fruit set. Only vines that are at least two years old can flower and bear fruit.
Propagation Methods
Luo Han Guo is primarily propagated by seed and layering, though it can also be propagated by cuttings.
Cultivation Techniques
1. Propagation by Seed
(1) Seed Collection and Treatment: In September–October, when the fruit peel turns from light green to bluish-green, harvest the mature fruits. Place them on a bamboo mat or the floor to undergo after-ripening for 10–15 days. Once the peel turns yellow, cut open the fruits, rinse the seeds in clean water, and air-dry them. Then, stratify the seeds with 3–5 times their volume of moist sand to stimulate germination.
(2) Sowing: Direct seeding or seedling transplantation may be used. Spring sowing is recommended in March–April. ① For direct seeding, dig holes in the prepared planting area with a row spacing of 2.0 m × 1.5 m and a hole depth and diameter of 30–35 cm each. Loosen the bottom soil, apply 3 kg of well-rotted manure or compost as a base fertilizer to each hole, and then cover the fertilizer with soil to a depth of about 10 cm.Then, scatter 3–5 seeds per hole, immediately cover with soil, water, and cover with straw to retain heat and moisture; seedlings will emerge in about 20 days. After emergence, promptly remove the covering and proceed with routine seedbed management. ② Row sowing: Open shallow sowing furrows with a row spacing of 18–20 cm, a depth of 1.5 cm, and a sowing width of 5 cm.Then, scatter the seeds evenly into the furrows, cover with soil until level with the bed surface, and cover with straw to retain heat and moisture. If the seedbed soil is dry, water it to moisten the soil before sowing. The seed germination rate is approximately 40%. Cultivate until early spring of the following year, then dig up the robust underground tubers for transplanting.
2. Propagation by Layering
In the fall, select vigorous, long-internode, small-leaved, round-tipped, pale greenish-white, drooping, and fruitless shoots from 1- to 2-year-old plants as layering material. Around the time of the Autumnal Equinox, when temperatures range from 25–28°C, choose a cloudy or rainy day to perform the layering on-site.First, dig a hole 25 cm long, 15 cm wide, and 10 cm deep in the ground near the area where the cuttings will be laid. Bend the terminal shoot of the vine into the hole, ensuring the buried portion is 6–9 cm long. Each hole can accommodate 3–5 cuttings, spaced approximately 3–5 cm apart. After laying the cuttings, cover them with fine soil to a depth 3–4 cm above the bed surface, and cover with weeds to retain moisture.Water during dry periods to keep the soil consistently moist; roots will form in about 10 days, and the underground tubers will gradually swell after one month. After the start of winter, when the vines wither, dig up the tubers and store them in sand in a cellar for the winter; remove them the following spring for planting. Large tubers can be cut into 3–5 cm segments, stored in sand to induce sprouting, and used as seedlings.
3. Propagation by Cuttings
From June to September, use semi-woody lateral shoots cut into 20-cm-long cuttings. Bundle 30–50 cuttings together. Dip the lower end of each cutting, near a node, into a 500 ppm rooting powder (ABT) or 500 ppm acetic acid (NAA) solution for 10 seconds.If the above solutions are unavailable, soak the cuttings in willow-infused water for 24 hours before removing them. Plant them in a seedbed prepared with sandy soil or sandy loam, with buds facing upward, at a spacing of 20 cm × 10 cm.After planting, erect a low shade structure to provide shade for 30–40 days, and maintain the seedbed soil moisture content at 50%–60% at all times. Roots will form in about 40 days, with a seedling survival rate of over 95%. Dig up the underground tubers the following spring for transplanting.
Pest and Disease Control
1. Leaf Spot Disease
(1) Damage: Affects the leaves. The disease first attacks the lower leaves, causing necrotic spots to appear, and then gradually spreads upward to the upper leaves. In the later stages of the disease, under hot and humid conditions, a gray-green mold-like substance with small black dots develops on the affected areas, and most leaves die off.
(2) Control Measures: Reduce nitrogen fertilizer application during the growing season, as the disease is more severe in plants that are overly tender and dense; ensure proper drainage during the rainy season to lower field humidity, which can help reduce the incidence of the disease;Increase the application of phosphorus and potassium fertilizers to enhance the plants’ disease resistance; in conjunction with pinching and topping, remove diseased lower leaves and burn them in a centralized location; in the early stages of the disease, spray a 50% carbendazim solution diluted 800–1,000 times or a 50% thiophanate-methyl solution diluted 1,000–1,500 times, once every 7–10 days, for a total of 3–4 applications.
2. Root-knot Nematode Disease
(1) Damage: Affects roots and tubers. Once infected, plants first develop root galls of varying sizes on the fibrous roots, forming a bead-like pattern; later, tuberous galls also appear on the tubers. In severe cases, the entire tuber rots, resulting in a complete crop failure.
(2) Control Methods: Select disease-free tubers for planting; implement crop rotation with cereal crops;during land preparation, apply 5 kg of 3% methyl isothiophos per mu; spread it on the ground and incorporate it into the soil to disinfect the soil; in the spring when loosening the soil around the base of the plants, promptly remove any galls found and coat them with tung oil for control.
3. Yellow Melon Moth
(1) Damage: Adult moths feed on leaves, causing holes and notches; they also damage flowers, affecting fruit set.
(2) Control Methods: Clean the orchard in winter by collecting and burning dead branches and diseased leaves to eliminate overwintering insect populations; when infestations occur, spray a 1,000-fold dilution of 98% diazinon, an 800–1,000-fold dilution of 50% dichlorvos, or a 2,000–3,000-fold dilution of 10% cypermethrin.