Yellow-Fruit Nightshade (Solanum virginianum L.): A Comprehensive Reference
1. Identity: Botanical Classification, Nomenclature, and Natural Source
1.1 Accepted Name and Synonyms
Solanum virginianum, also called Surattense nightshade, yellow-fruit nightshade, yellow-berried nightshade, Indian nightshade, Thai green eggplant, or Thai striped eggplant (from the unripe fruit), is a medicinal plant used mostly in India. Solanum surattense Burm. f. and Solanum xanthocarpum Schrad. and Wendl. are synonyms of Solanum virginianum L. The name xanthocarpum is directly descriptive: the name is given because Solanum means nightshade, xantho means yellow, and carpum means fruit; the major phytoconstituents found in roots and other parts include solasonine, coumarins, scopolin, scopoletin, and esculin.
In Sanskrit and Ayurvedic literature, the plant is most commonly known as Kantakari (also spelled Kantkari or Kantakiri). The name Kantakari itself is derived from Sanskrit, meaning "the one which is good for the throat," highlighting its historical and therapeutic significance in promoting vocal health. Other vernacular names include Choti Kateri, Kateli, Ringini, Vyaghri, Nidigdhika, and Bhauringani.
1.2 Taxonomic Classification
Botanical name: Solanum xanthocarpum; Kingdom: Plantae; Division: Magnoliophyta; Class: Magnoliopsida; Subclass: Asteridae; Order: Solanales; Family: Solanaceae; Genus: Solanum.
1.3 Botanical Description
Yellow-fruit nightshade (Solanum virginianum L.) is a prickly, erect or spreading perennial herb or subshrub in the nightshade family (Solanaceae), characterized by its stellate-hairy stems armed with yellow prickles, deeply lobed green leaves, violet or blue star-shaped flowers, and globose yellow fruits about 1–2 cm in diameter. It is an erect herb, sometimes woody at the base, measuring 50–70 cm (20–28 in) tall, and is copiously armed with sturdy, needlelike, broad-based prickles measuring 5–20 mm × 0.5–1.5 mm. Its small, round berries transition from green to yellow as they mature.
1.4 Geographic Distribution
Native to seasonally dry tropical regions, it thrives in disturbed habitats such as roadsides, wastelands, degraded forests, and dry open areas up to 1,500 meters elevation. Widely distributed across tropical and subtropical Asia—from the Arabian Peninsula and Iran through India, Pakistan, and China to Southeast Asia (including Myanmar and Malaysia)—as well as northeastern tropical Africa, the plant has been introduced to regions like Madagascar, Mauritius, and parts of the United States. This plant is widely found in India, in Uttar Pradesh, West Bengal, Assam, Bihar, Punjab, and also in Ceylon and Malacca through South-East Asia, tropical Australia, and Polynesia.
1.5 Common Preparations and Forms
In regions such as Southeast Asia, leaves are applied topically to treat skin infections and wounds, often in the form of pastes. Preparation methods in these traditions include decoctions from roots or whole plant, pastes from leaves for external application, and smokes from dried herb for respiratory relief. Ancient Ayurvedic practitioners often included Kantakari in herbal formulations aimed at respiratory conditions, digestive issues, and inflammatory disorders, commonly used in powders, decoctions, and pastes. In the Ayurvedic Pharmacopoeia of India, it has been mentioned that the formulations 'Dasmul Asava' and 'Dashmularishta' containing roots of the plant are used as a tonic for lactating mothers.
2. Traditional and Historical Use
2.1 Ayurveda
Kantakari is well-documented in ancient Ayurvedic texts, where it is recognized for its diverse therapeutic properties. Key texts such as the Charaka Samhita and the Sushruta Samhita reference Kantakari, highlighting its applications in treating various ailments. Charaka is thought to have flourished between the 2nd century BCE and 2nd century CE, and the Charaka Samhita as it exists today is thought to have arisen in the 1st century CE. The plant therefore has a textual history of use spanning roughly two millennia.
Kantakari is widely used in treating various types of jwara (fever), tamakaswasa (bronchial asthma), kasa (cough), and hikka (hiccough). Ayurveda describes the herb as bitter, digestive, pungent, and alternative astringent in ancient times; stems, flowers, and fruits are described as bitter and carminative.
Known as one of the Dashamoola, a revered group of ten roots in Ayurveda, Kantakari holds a special place in herbal medicine for its comprehensive healing properties. According to ancient philosophies such as Charaka and Sushruta Samhita, Dashamoola is a traditional Ayurvedic formula comprising 10 dried roots of 10 different plants. This Ayurvedic concoction has been used for many years in Indian medicine. Yellow Berried Nightshade is one of the chief ingredients in Dashamoola Rasayanam, an Ayurvedic preparation for the treatment of respiratory ailments.
Texts describe Kantakari as effective for balancing the Vata and Kapha doshas, making it valuable in treatments for conditions associated with these imbalances, such as cough, asthma, and obesity. In Ayurvedic terminology, Kantakari is sometimes associated with Rasayana (rejuvenation) therapies, believed to enhance vitality and overall health.
2.2 Siddha Medicine
Solanum xanthocarpum and Solanum trilobatum are widely used to treat respiratory diseases in southern Indian traditional medicine (Siddha). In the Siddha tradition, which is especially prevalent in Tamil Nadu, preparations of the whole plant have been employed specifically for bronchial conditions and as expectorants.
2.3 Unani and Broader Folk Use
In traditional Indian medicine systems such as Ayurveda and Siddha, the whole plant or roots of yellow-fruit nightshade are commonly employed to alleviate respiratory ailments, including asthma, cough, and bronchitis. Fruits of the plant are traditionally utilized for their febrifuge properties to reduce fever and provide relief from pain. Its significance extends to digestive well-being, as it is believed to stimulate appetite, aid digestion, and alleviate abdominal discomfort. In rural communities, Yellow-Fruit Nightshade has also been utilized as a natural diuretic and to manage urinary disorders, showcasing its versatility in folk remedies.
The plant is described in classical sources as bitter, acrid, thermogenic, anthelmintic, anti-inflammatory, digestive, carminative, appetizer, stomachic, febrifuge, expectorant, laxative, stimulant, diuretic, rejuvenating, emmenagogue, and aphrodisiac.
3. Key Constituents and Active Compounds
3.1 Steroidal Alkaloids (Glycoalkaloids)
Steroidal alkaloids are the main chemical constituents mainly found in the fruits of this plant. Mostly steroidal alkaloids and triterpenoids, such as solamargine, solanidine, solasodine, solasonine, tomatidine, xanthosaponin A–B, dioscin, lupeol, and stigmasterol are biologically the most active metabolites with high potency.
Solasodine is the principal aglycone alkaloid. The solasodine content of the berries of S. xanthocarpum is reported to vary from 1.1% to 4.6% depending on climatic and soil conditions. Berries collected in autumn (September, October) yielded only solasonine and solamargine without any trace of solasurine, which was obtained from the material collected in summer (May, June). The solasodine content of the unripe berries was 1.7% on a dry weight basis.
Fruits are reported to contain several steroidal alkaloids including solanacarpine, solanacarpidine, solancarpine, solasonine, solamargine, and other constituents like caffeic acid, coumarins such as aesculetin and aesculin, steroids carpesterol, diosgenin, campesterol, daucosterol, and triterpenes such as cycloartenol.
3.2 Flavonoids, Phenolics, and Other Compounds
Qualitative phytochemical screening of Solanum xanthocarpum seed extracts reveals the presence of polyphenols, flavonoids, glycoside, alkaloids, carbohydrates, and reducing sugar in the plant. Based on preliminary qualitative phytochemical screening, quantitative estimation of polyphenols has been performed; the quantitative estimation of alcoholic extracts found significant amounts of polyphenols, as compared to aqueous extracts.
The plant contains alkaloids, sterols, saponins, flavonoids and their glycosides, and also carbohydrates, fatty acids, and amino acids. Compounds such as carpesterol, diosgenin, and stigmasterol are found to have anti-inflammatory action. Lupeol is a constituent of Solanum xanthocarpum and has immense anti-inflammatory potential, acting as a multitargeting agent.
3.3 Fatty Acid and Volatile Constituents
GC-MS study on the bioactive components of S. xanthocarpum has shown the presence of 9,12,15-Octadecatrienoic acid, (Z,Z,Z), which possesses anti-inflammatory, hypocholesterolemic, antihistaminic, antiarthritic, and anti-coronary activities; Hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl) ethyl ester, which has antiarrhythmic, antiinfarctal, anti-inflammatory, hypotensive, and inotropic activities; and 2,6,10,14,18,22-Tetracosahexaene, 2,6,10,15,19,23-hexamethyl-, (all-E), which has antioxidant, immune stimulant, and lipoxygenase-inhibitory activities.
4. Mechanisms of Action
4.1 Respiratory / Bronchodilatory Mechanisms
The glycoalkaloid and fatty acid fractions of the plant extract cause a release of histamine from chopped lung tissue. The beneficial effect of the drug for bronchial asthma may be attributed to the depletion of histamine from bronchial and lung tissue. This histamine-depleting mechanism has been proposed as a central explanation for the plant's traditional use in asthma.
The improvement in peak expiratory flow rate (PEFR) and the reduction in other symptom scores clearly indicate a bronchodilator effect, a decrease of edema, and reduction of secretions in the airway lumen.
4.2 Anti-Inflammatory Mechanisms
Solanidine, α-solanine, and α-chaconine are found to have anti-inflammatory effects. Compounds such as carpesterol, diosgenin, and stigmasterol are also found to have anti-inflammatory action. Steroidal alkaloids have been presented as being largely responsible for various pharmacological activities of Solanum species, including anti-inflammatory, antibacterial, anticonvulsant and CNS depressant, antidiabetic, anti-fungal, antileishmanial, molluscicidal, antioxidant and antitumor, antiprotozoa, spasmolytic, and anti-trypanosomal activities.
4.3 Anticancer / Pro-apoptotic Mechanisms
Solamargine and apigenin are chemical constituents from Solanum xanthocarpum which have anticancer activity. It was observed in solamargine-treated cells that sub-G1, DNA fragmentation, and condensation of chromatin in DNA suggested that apoptosis was induced by solamargine.
4.4 Antispermatogenic Mechanism
Solasodine is well tolerated and inhibits spermatogenesis and sperm motility. No significant change was noticed in the weight of testes and accessory sex organs. The RNA, protein, sialic acid, and glycogen contents of the testes were reduced significantly; serum proteins, triglycerides, serum enzymes (GOT/GPT/Alkaline phosphatase), and nonesterified fatty acid levels were in normal range. Solasodine is estrogen-free but inhibits testosterone release from dispersed mouse Leydig cells.
4.5 Antioxidant Mechanisms
In-vitro antioxidant studies have been performed by two methods: DPPH, and a superoxide radical scavenging method. The alcoholic extracts showed significant antioxidant properties, as compared to aqueous extracts. Extracts of Solanum species have shown potential antioxidant power in DPPH radical scavenging, ABTS, FRAP, O2·⁻, H2O2, and related assays. A positive correlation was noticed between the antioxidant activity and the content of alkaloids, signifying that these compounds contribute to radical scavenging potentiality.
5. Scientific Evidence by Area of Use
5.1 Respiratory System: Bronchial Asthma and Airway Function
This is the most studied area of the plant's activity and the one with the strongest (though still limited) human evidence.
5.1.1 Pilot Clinical Trial (1999)
A pilot study was undertaken to investigate the clinical efficacy and safety of a single dose of the above herbs in mild to moderate bronchial asthma. The respiratory functions (FVC, FEV1, PEFR, and FEF25–75%) were assessed by using a spirometer prior to and 2 hours after oral administration of 300 mg powder of whole plant of either S. xanthocarpum or S. trilobatum. Standard bronchodilator drugs, salbutamol (4 mg) and deriphylline (200 mg) were used for comparison. Treatment with either S. xanthocarpum or S. trilobatum significantly improved the various parameters of pulmonary function in asthmatic subjects; however, the effect was less when compared to that of deriphylline or salbutamol. No untoward effects were reported during the study. The results of the present study confirm the traditional claim for the usefulness of these herbs in bronchial asthma. More detailed studies are required to investigate the mechanism of action and therapeutic utility of S. xanthocarpum and S. trilobatum.
5.1.2 Follow-up Clinical Trial (2004)
The clinical efficacy of two herbs S. xanthocarpum and S. trilobatum in a dose of 300 mg three times daily for 3 days was investigated in mild to moderate bronchial asthma. Their effect was compared with standard bronchodilator drugs, salbutamol (4 mg) and deriphylline (200 mg). The respiratory function was assessed by measuring the peak expiratory flow rate (PEFR) using a mini peak flow meter. In addition, improvement in lung function was assessed by physical examination (rhonchi and crepitation) and other symptoms such as cough, breathlessness, and sputum. S. xanthocarpum and S. trilobatum produced a progressive improvement in the ventilatory function of asthmatic individuals over 3 days. The scores for rhonchi, cough, breathlessness, and sputum were decreased by these drug treatments. The improvement in PEFR and the reduction in other symptom scores clearly indicate a bronchodilator effect, a decrease of edema, and reduction of secretions in the airway lumen.
5.1.3 Specific Outcomes from the 60-Subject Trial
In this trial, 60 adults aged 18–50 years with mild-to-moderate asthma took part in a single-day trial. Participants received either 300 mg oral Solanum xanthocarpum or 300 mg oral Solanum trilobatum (CAM commonly used in southern Indian Siddha medicine) as the intervention, and 200 mg deriphylline or 4 mg salbutamol as the control. Lung function was assessed using forced vital capacity (FVC), FEV1, and PEFR. Compared to salbutamol, post-intervention FEV1 and FVC were significantly greater with S. xanthocarpum (p<0.05). PEFR improvement was significantly greater compared to deriphylline (p<0.01). There was no significant difference between the S. trilobatum intervention group and the two controls.
5.1.4 Overall Evidence Assessment for Respiratory Use
A systematic review by the European Respiratory Society concluded that evidence is insufficient to recommend complementary and alternative medicines in the management of asthma. The existing human trials for S. xanthocarpum are small in sample size, short in duration (single dose to 3 days), and lack rigorous blinding and allocation concealment procedures that are standard in modern randomized controlled trials. While the results are directionally positive and lend scientific support to the traditional use, they should be considered preliminary evidence only.
5.2 Anti-Inflammatory Activity
In continuation of research for potent natural anti-inflammatory agents, the anti-inflammatory activity of ethanol extract of S. xanthocarpum whole plant was evaluated at doses of 10, 30, and 100 mg/kg p.o. in rats, using pharmacological screening models including carrageenan-induced rat paw edema, histamine-induced rat paw edema, and cotton pellet granuloma. Data was analyzed statistically using analysis of variance followed by post-hoc Dunnett test (P < 0.05 considered significant). Notably, acute treatment did not show anti-inflammatory activity against carrageenan- and histamine-induced paw edema. This is a preclinical animal finding and does not constitute clinical evidence in humans. No high-quality human trials specifically assessing anti-inflammatory endpoints have been identified for this plant.
The extracts of Solanum xanthocarpum and Cassia fistula have been reported to possess anti-inflammatory activity. One study was conducted to determine whether both these plant extracts showed increased anti-inflammatory activity at low dose when given in combination. This investigation, conducted in animal models, provides only preclinical evidence.
5.3 Antioxidant Activity
The antioxidant activity of S. xanthocarpum has been investigated exclusively in vitro and in animal models. In-vitro antioxidant and in-vivo antimutagenic properties of Solanum xanthocarpum seed extracts have been examined by qualitative phytochemical screening, which reveals the presence of polyphenols, flavonoids, glycoside, alkaloids, carbohydrates, and reducing sugar. The quantitative estimation of alcoholic extracts found significant amounts of polyphenols, as compared to aqueous extracts. In-vitro antioxidant studies have been performed by DPPH and a superoxide radical scavenging method, with alcoholic extracts showing significant antioxidant properties, as compared to aqueous extracts. These findings are preclinical; no human trials have evaluated antioxidant endpoints for this specific plant.
5.4 Anticancer Activity
Among the metabolites, 51 were identified and biologically tested, presenting antioxidant, anti-inflammatory, and antitumoral effects as the most reported activities. Clinical trials in humans made with the whole plant extract showed its efficacy as an anti-asthmatic agent. Mostly steroidal alkaloids and triterpenoids, such as solamargine, solanidine, solasodine, solasonine, tomatidine, xanthosaponin A–B, dioscin, lupeol, and stigmasterol are biologically the most active metabolites with high potency. Regarding cancer, the evidence is limited to in-vitro and animal models. More experimental studies and a deeper understanding of this plant must be conducted to ensure its use as a source of raw materials for pharmaceutical use.
5.5 Antispermatogenic / Antifertility Activity
Solasodine, an alkaloid of Solanum xanthocarpum, possesses antispermatogenic activity. In Dixit VP's 1980 study, chronic administration of solasodine (20 mg/kg every other day orally for 60 days) rendered male rats and dogs infertile. A mating test showed 87% infertility in rats, which returned to normal after 60 days' cessation of drug feeding. Chronic administration of solasodine (20 mg/kg alternate days for 30 days) caused testicular lesions resulting in severe impairment of spermatogenic elements. The epididymides were devoid of spermatozoa. These studies were conducted in animal models only; no human clinical trials on antifertility effects have been published. Solasodine can potentially be used to develop a male pill of plant origin. This remains a research proposition rather than a clinical reality.
5.6 Antimicrobial Activity
The leaf of Solanum xanthocarpum shows varieties of pharmacological activities which include antifungal, wound healing, antibacterial, antihyperglycemic, antioxidant, hepatoprotective, and larvicidal activities. There are a number of studies done on the antibacterial and antifungal activity of S. xanthocarpum, and it is found that the methanolic extract of leaves, root, and fruit of Solanum xanthocarpum possesses antibacterial as well as antifungal properties. All available antimicrobial evidence is preclinical (in vitro and animal), and no controlled human trials have been conducted.
5.7 Antithrombotic Activity
Phytoconstituents present in S. xanthocarpum have been shown to possess antifertility, anti-inflammatory, antiallergic, antioxidant, hepatoprotective, nephroprotective, antibacterial, and anticancer activities. Solanum xanthocarpum and Tinospora cordifolia have been reported to exhibit anti-inflammatory, antiarthritic, antioxidant, antiallergic, and hepatoprotective activities. Investigation of antithrombotic activities via methanolic leaf extracts has been undertaken by thrombin inhibition assay, thrombin generation assay, platelet adhesion assay on collagen-coated surfaces, and platelet PAC1-FITC binding by flow cytometry. These investigations are preclinical and do not yet constitute human evidence.
5.8 Hepatoprotective and Other Activities
S. xanthocarpum has outstandingly demonstrated the most diverse pharmacological activities, including antioxidant and antitumor, anti-fungal, anti-bacterial, antileishmanial, mosquito larvicidal, molluscicidal, antidiabetic, asthmatic, hepatoprotective, diuretic, nephrotoxicity, antinociceptive, anti-psoriatic, and antiurolithiatic activities. Exhaustive literature availability reveals the presence of phytochemical compounds from different plant parts like roots, stem, leaves, fruits, and seeds, reported to possess a wide range of pharmacological activities like hepatoprotective, cardioprotective, antiasthmatic, and mosquito repellent properties. All hepatoprotective claims for this specific species are based on preclinical studies.
6. Body Systems and Health Areas Associated with Yellow-Fruit Nightshade
- Respiratory system: Commonly employed to alleviate respiratory ailments, including asthma, cough, and bronchitis. This is the most clinically evaluated area.
- Gastrointestinal system: The herb is also a digestive and a carminative, which facilitates the treatment of gastrointestinal problems. Yellow Berried Nightshade facilitates the treatment of gastrointestinal disorders like constipation and flatulence, because of its laxative and carminative properties.
- Urinary system: In rural communities, Yellow-Fruit Nightshade has been utilized as a natural diuretic and to manage urinary disorders.
- Reproductive system: The plant shows anti-androgenic activity due to the presence of solasodine, an alkaloid constituent; solasodine was found to have antifertility effects in male rats and canines in subsequent investigations.
- Immune and inflammatory system: Phytoconstituents present in S. xanthocarpum have been shown to possess anti-inflammatory, antiallergic, and antioxidant activities in preclinical studies.
- Integumentary system (skin): In Southeast Asia, leaves are applied topically to treat skin infections and wounds, often in the form of pastes.
- Cardiovascular system: GC-MS study on the bioactive components of S. xanthocarpum has shown the presence of compounds which possess anti-inflammatory, antiarrhythmic, antiinfarctal, hypotensive, and inotropic activities, though these remain preclinical observations.
7. Dosage Forms and Doses Reported in Studies
Dosage information in the published scientific literature is limited and derives mainly from the clinical trials on bronchial asthma and from traditional Ayurvedic references:
- Oral powder, single dose (clinical study): Respiratory functions were assessed prior to and 2 hours after oral administration of 300 mg powder of whole plant of S. xanthocarpum.
- Oral powder, multiple doses (clinical study): The clinical efficacy of S. xanthocarpum was investigated at a dose of 300 mg three times daily for 3 days in mild to moderate bronchial asthma.
- Solasodine (animal research, antispermatogenic): In animal research, chronic administration of solasodine at 20 mg/kg every other day orally for 60 days was used in male rats and dogs.
- Animal anti-inflammatory study: The ethanol extract was evaluated at doses of 10, 30, and 100 mg/kg p.o. in rats.
- Traditional Ayurvedic dosage references: Traditional dosages include powder: 1–3 g or decoction prepared from roots or whole plant.
No standardized pharmaceutical dose has been established for human use by any major regulatory or pharmacopeial authority. The doses above reflect those reported in specific studies and should not be interpreted as therapeutic recommendations.
8. Safety Considerations
8.1 Fruit Toxicity
Solanum virginianum is a medicinal plant used mostly in India. Some parts of the plant, such as the fruit, are poisonous. Raw fruits can be slightly toxic; proper drying and processing are essential to reduce harmful alkaloids and enhance efficacy.
8.2 Glycoalkaloid Toxicity (Class-Level Concern)
Solanaceae plants contain alkaloids with toxicity to humans and animals, ranging from mild irritation to fatal outcomes. Solanine poisoning is primarily displayed by gastrointestinal and neurological disorders. Symptoms include nausea, diarrhea, vomiting, stomach cramps, burning of the throat, and cardiac dysrhythmia. Solanine poisoning is primarily displayed by gastrointestinal and neurological disorders. Symptoms include nausea, diarrhea, vomiting, stomach cramps, burning of the throat, cardiac dysrhythmia, nightmares, headache, dizziness, itching, eczema, thyroid problems, and inflammation and pain in the joints. In more severe cases, hallucinations, loss of sensation, paralysis, fever, jaundice, dilated pupils, hypothermia, and death have been described. These descriptions refer to glycoalkaloid poisoning from Solanum species generally.
8.3 Antispermatogenic Risk
Chronic administration of solasodine (20 mg/kg alternate days for 30 days) in dogs caused testicular lesions resulting in severe impairment of spermatogenic elements, and the epididymides were devoid of spermatozoa. Cholesterol and phospholipid levels were elevated after solasodine treatment to intact dogs. Reduced androgen production was reflected in low levels of sialic acid in the testes and epididymides and reduced Leydig cell nuclei. Although these findings are from animal studies, they are relevant given the concentrations of solasodine found in the plant's fruits and the proposed development of solasodine as a male contraceptive agent.
8.4 Hemolytic Activity
Beta-solamarine, solamargine, and chaconine in in-vitro studies exhibited hemolytic properties against red blood cells. In addition to other activities, a minute amount of hemolytic activity has been observed in extracts of the plant. This is a preclinical finding with unknown clinical relevance at traditional dose levels.
8.5 No Adverse Events in Short-Term Human Trials
No untoward effects were reported during the short-term pilot study that administered 300 mg of whole-plant powder as a single dose to mild-to-moderate asthmatic subjects. This represents the most direct human safety data available, but is limited by small sample size and very short follow-up duration.
8.6 Potential Drug Interactions and Contraindications
High solanine levels (rare in quality preparations) can lead to headaches, dizziness, or low blood pressure. The plant is suggested to be avoided in peptic ulcer patients, as its bitter compounds may exacerbate gastric mucosa irritation. It may potentiate antihypertensive agents and sedatives; caution is indicated with concurrent diuretic use. These cautions reflect theoretical concerns based on the plant's alkaloid profile and its proposed pharmacological actions; they are not derived from formal drug interaction studies.
8.7 Overall Safety Context
Most Solanum members contain certain metabolites like glycoalkaloids that confer toxicity. Plants naturally produce alkaloids as a defense mechanism against certain insects and fungi to protect themselves from external factors. Formal systematic toxicological studies specific to S. virginianum in humans are lacking; safety assessments must therefore draw on the alkaloid class literature and limited short-term clinical observations.
References
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