Noni (Morinda citrifolia L.): A Comprehensive Reference
1. Identity: Botanical Names, Natural Source, and Common Forms
1.1 Botanical and Scientific Identity
Morinda citrifolia L., known as noni, is a tropical plant belonging to the Rubiaceae family and is widely used in traditional medicine for its therapeutic properties. It is a small evergreen tree native to Southeast Asia and Australia, now widely cultivated across tropical and subtropical regions, including the Pacific Islands, Puerto Rico, the Dominican Republic, and Brazil, particularly in the Central-West and Northeast regions.
Belonging to the genus Morinda within the Rubiaceae family, this evergreen perennial broad-leaved shrub is a quintessential example of an "exotic fruit." Distinguished by its large lanceolate leaves, straight stems, and grenade-shaped fruit, noni exhibits a continuous flowering and fruiting cycle throughout the year. The plant can grow as a shrub, or small or medium-sized tree 3 to 10 meters high that grows in tropical coastal regions around the world.
The immature fruit is initially green in color, turning yellow as it ripens and softening when it becomes overripe. The noni flowers develop into compound fruits composed of many small drupes fused into an ovoid, ellipsoid or roundish, lumpy body, with waxy, white, or greenish-white or yellowish, semi-translucent skin. The fruit contains "eyes" on its surface, similar to a potato.
1.2 Common Names and Synonyms
The plant bears a large number of common names across different regions and cultures, including: Indian mulberry, Mengkudu, Morinda, Nhau, Noni, Nono, Nonu, and many others. As a result of growth in different geographic locations, it has various names, including noni in Hawaii, nono in Tahiti, Indian mulberry in India, Ba ji tian in China, and cheesefruit in Australia. In the South Pacific regions of Samoa and Tonga, this plant is known as Nonu; in Malaysia it is Mengkudu; in Tahiti as Raratonga; and in Hawaii and the Marquesas Islands as Noni.
1.3 Common Preparations and Dosage Forms
All major plant parts — including the juice, roots, stems, bark, leaves and flowers — have been used as medicinal remedies in Polynesia for centuries and recently in the Western world for a wide range of medical problems.
Commercial preparations include:
- Fermented juice: The most commercially prevalent form. A leading commercial product (Tahitian Noni Juice, TNJ) is composed of noni fruit juice from puree (89%) that is mixed with grape (Vitis vinifera) and blueberry (Vaccinium corymbosum) juices.
- Fruit puree: Used both in traditional practice and as a commercial novel food ingredient approved in Europe.
- Capsules and tablets: Standardized extracts used in clinical studies. In a Phase I clinical study involving 51 patients with advanced cancers, patients were enrolled at seven dose levels of noni extract.
- Topical preparations: Leaf poultices and noni-based oils applied to the skin in traditional settings.
- Tea/decoctions: Prepared from leaves and roots, used across multiple traditional medicine systems.
Products derived from the fruit of Morinda citrifolia have been commercialized in the USA since the 1990s and are increasingly distributed all over the world. In European countries, the fruit juice of noni was approved as a novel food by the European Commission in 2003.
2. Traditional and Historical Use
2.1 Polynesia and the Pacific Islands
Morinda citrifolia, commonly known as noni, is a perennial plant originating in Southeast Asia that has been consumed for over 2,000 years. Cultivated and consumed for over 2,500 years, noni holds a special place in Polynesian traditional medicine.
Of all the two-dozen canoe plants that Hawaiians brought on their migrations, noni was the only one that was primarily or exclusively used for medicinal purposes. Ancient Polynesians identified noni, along with taro and banana, as essential to life, and it was carried on canoe voyages throughout the Pacific. As Pacific Island voyagers explored different island regions, they brought vital plants in their canoes to establish living communities. Noni was a crucial canoe plant — if an island did not have a noni plant, they would plant one to help future generations.
Noni has traditionally been used for colds, flu, diabetes, anxiety, and hypertension, as well as an antidepressant and anxiolytic. All plant parts are used for a variety of illnesses in Samoan culture, and noni is one of the most frequently used Hawaiian plant medicines.
In Hawaiian traditional medicine, different plant parts were prepared and used in distinct ways: the leaves and bark of the stem were pounded and strained, resulting in a liquid drunk as a tonic or for urinary disorders, muscle and joint pain. The leaf was also heated over a fire or with an iron to bring out the oils, and then wrapped as a type of poultice for areas of skin that are inflamed, bruised, burned, or otherwise in need of healing.
Noni is used both as a regular tonic for health maintenance, and is also said to be used when one is feeling really ill or really old. During times of famine, Polynesians prized it as a vital source of nutrition.
2.2 Indian Subcontinent and Ayurvedic Tradition
In Ayurvedic medicine, noni is classified as Tridoshagna — capable of pacifying all three vitiated doshas — with the fruit, leaf, and root being the primary parts used. The juice of the fruit was used at 20–30 mL and decoctions at 50–70 mL. The main micronutrients of M. citrifolia pulp powder include vitamin C, niacin (vitamin B3), iron, and potassium, with vitamin A, calcium, and sodium present in moderate amounts.
2.3 Southeast Asia, China, and Other Regions
Roots of Morinda citrifolia have been used traditionally for thousands of years in Thailand to treat chronic diseases such as cancer and heart disease. In traditional Chinese folk medicine, especially in Hainan and Guangdong provinces, where villagers called it Ba Ji Shi, decoctions were used to alleviate rheumatic pain.
Both the inner bark of branches and roots have historical use in dye-making: a red to purple dye is harvested from branches, and yellow dye comes from the roots.
2.4 Additional Traditional Applications
Noni fruit juice has conventionally been used for special disorders such as atypical menstruation, acne/boils, diarrhea, hard stool formation, autoimmune rheumatoid arthritis, hyperglycemia, fever, tachycardia, peptic ulcers, anxiety and other psychological disorders, poor digestion, hyperlipidemia, and blood vessel troubles. The juice of the fruit was also applied to the hair to rid it of head lice.
3. Key Constituents and Active Compounds
3.1 Phytochemical Overview
Chemical and nutritional analyses of M. citrifolia reveal the existence of more than 200 phytochemical substances with bioactive properties, such as acids, alcohols, phenols, saccharides, anthraquinones, carotenoids, esters, triterpenoids, flavonoids, glycosides, lactones, iridoids, ketones, lignans, nucleosides, triterpenides, sterols, and aromatic compounds.
The concentration and distribution of these compounds differ substantially across plant parts: noni leaves have flavonoids, triterpenoids, alkaloids, coumarins, anthraquinones, saponins, tannins, carotenoids, organic acids, and reducing agents; its fruits have a large amount of polyphenols and antioxidant agents; and its roots have a chemical composition marked by the presence of anthraquinones.
3.2 Major Bioactive Compound Classes
Iridoids
Key iridoid compounds include aucubin, asperulosidic acid, deacetylasperulosidic acid, and asperuloside. Purification of fruit extracts has led to the isolation of iridoid glucosides including 6α-hydroxyadoxoside and 6β,7β-epoxy-8-epi-splendoside, as well as asperuloside, asperulosidic acid, deacetylasperuloside, and related compounds. The iridoid deacetylasperulosidic acid (DAA) has been specifically investigated as a contributor to the antioxidant activity observed in human clinical studies of noni juice.
Anthraquinones
Damnacanthal, an anthraquinone compound, is isolated from the roots of Morinda citrifolia L. and has been used for traditional therapy in several chronic diseases, including cancer. Other anthraquinones isolated from M. citrifolia include alizarin, morindadiol, nordamnacanthal, rubiadin, ibericin, tectoquinone, lucidin, damnacanthol-ω-ethyl ether, and several others. Three compounds — asperulosidic acid (an iridoid glycoside), damnacanthal (an anthraquinone), and scopoletin (a coumarin) — have demonstrated in vitro cellular/molecular effects possibly relevant to the inhibition of cancer development and progression.
Coumarins (Scopoletin)
Scopoletin, an active principle obtained from Morinda citrifolia, has been shown to efficiently quench oxidative stress through DJ-1/Nrf2 signaling. In vitro studies revealed that scopoletin lessened rotenone-induced apoptosis in SH-SY5Y cells through preventing oxidative injury. Specifically, scopoletin markedly upregulated DJ-1, which then promoted the nuclear translocation of Nrf2 and transactivation of antioxidant genes.
Flavonoids
Key flavonoids present in noni include kaempferol and rutin.
Polysaccharides
Noni polysaccharides are predominantly pectic polysaccharides, comprising homogalacturonan and rhamnogalacturonan-I regions, alongside minor hemicellulose-derived components such as (xylo)glucans. Extraction of noni polysaccharides is usually done by extracting the juice or puree with distilled water, centrifugation of the extract, and precipitation with alcohol. The crude polysaccharide content in noni fruit decreases significantly as it matures, from 1.72 g/100 g to 1.07 g/100 g, as enzymes in noni break down the polysaccharides in the cell wall.
Alkaloid: Xeronine
Xeronine is an alkaloid that has been proposed as an important constituent of noni. Noni contains as chief constituents the alkaloid xeronine, scopoletin, and damnacanthal, and also contains vitamin A and C and minerals such as magnesium, potassium, and iron, as well as amino acids and ursolic acids. The scientific status of xeronine and its proposed mechanisms remains under debate in the peer-reviewed literature, with many of the original claims concerning a "xeronine system" resting on insufficiently replicated data.
4. Established and Proposed Mechanisms of Action
4.1 Antioxidant Mechanisms
Systematic analyses reveal that noni-derived compounds exhibit potent free radical scavenging capacity (e.g., DPPH/ABTS inhibition), upregulate endogenous antioxidant enzymes (Superoxide Dismutase [SOD], Catalase [CAT], Glutathione Peroxidase [GPx]), and modulate key pathways such as Nrf2/Keap1 and NF-κB. Notably, polysaccharides and iridoids demonstrate dual antioxidant and anti-inflammatory effects via gut microbiota regulation.
4.2 Anti-Inflammatory Mechanisms
Noni seed extract showed significant inhibition of nitric oxide (NO) production with no effect on cell viability. The extract was found to reduce the expression of inducible NO synthase and tumor necrosis factor-alpha of pro-inflammatory cytokines. An alcohol extract of noni fruit puree also caused inhibition of MMP-9 release from human monocytes after stimulation with LPS — an effect comparable to hydrocortisone at 10⁻⁵ m.
4.3 Anticancer Mechanisms
Research has demonstrated that M. citrifolia demonstrated various anticancer properties in different cancer models, via multiple mechanisms including antitumor, antiproliferative, pro-apoptotic, antiangiogenesis, antimigratory, anti-inflammatory, and immunomodulatory activities.
Damnacanthal inhibited the growth of MCF-7 breast cancer cells at the concentration of 8.2 μg/ml for 72 hours. The drug induced cell cycle arrest at the G1 checkpoint in MCF-7 cells and further induced apoptosis, determined by Annexin V-fluorescein isothiocyanate/propidium iodide (PI) dual-labeling, acridine-orange/PI dyeing, and caspase-7 expression. Damnacanthal's ability to target various tyrosine kinases shows promising anti-cancer activity in laboratory models.
4.4 Immunomodulatory Mechanisms
Noni polysaccharides have biological activities such as immunomodulation, antioxidant, anti-inflammatory, anti-tumor, and hypoglycemic activity. Various types of noni extracts have been researched and found to have good anti-inflammatory and immunomodulatory properties because of polysaccharides. A fraction from noni juice rich in complex sugars, alone and in conjunction with chemotherapy drugs, is able to increase the survival of laboratory mice implanted with lung cancer. Scientists are unsure exactly how noni exerts this effect, but observe that it enhances certain aspects of the immune system.
4.5 Analgesic Mechanisms
The analgesic activity of noni fruit puree was investigated in mice using the hot plate test. A 10% solution of freeze-concentrated noni fruit puree in the drinking water of mice reduced pain sensitivity comparably to the central analgesic drug tramadol. This effect was only partly reversed by the application of the morphine antagonist naloxone, suggesting both opioid and non-opioid pathways may be involved. These findings are, however, from animal models only.
5. Scientific Evidence by Area of Use
The NCCIH (National Center for Complementary and Integrative Health) summarizes the overall landscape: in laboratory research, noni has shown antioxidant, immune-modulating, antimicrobial, antifungal, and tumor-fighting properties. These results suggest that noni may warrant further study for various diseases. However, noni has not been shown to have beneficial effects on any health condition in studies of people.
5.1 Antioxidant Activity
Evidence strength: Preliminary human evidence, mostly from a single commercial product.
In a human clinical trial involving heavy cigarette smokers, consumption of noni juice resulted in lowered plasma concentrations of superoxide anion radicals (SAR) and lipid hydroperoxides. Further, consumption of noni juice also decreased the level of lipid peroxidation-derived DNA adducts in the lymphocytes of heavy smokers.
In a study of 203 subjects over 30 days, peripheral blood lymphocytes were isolated and evaluated for the degree of aromatic DNA adduct formation. By the end of the 30-day study period, average aromatic DNA adduct levels dropped by 44.9% (p < 0.001) among those drinking either one fluid ounce (29.5 mL) or four fluid ounces (118 mL) of noni juice per day. However, both studies were preliminary. Over 25% of participants did not complete the trial, and the noni juice and the placebo contained a mixture of grape and blueberry juice, which could have contributed to some of the beneficial effects reported.
5.2 Cancer
Evidence strength: In vitro and animal studies only; no randomized controlled trials in cancer patients.
In vitro and animal studies have shown potential antioxidant action, immune function stimulation, and antitumour activity, but there have been few trials in humans for any condition and no randomised controlled trials in cancer patients.
A systematic review was conducted to collate scientific evidence on the anticancer properties of M. citrifolia using pre-determined keywords on five electronic databases: MEDLINE, CENTRAL, LILACS, Web of Science, and EBSCOHost. A total of 51 clinical and preclinical studies comprising 41 efficacy and 10 safety studies were included in this review. The scientific evidence gathered was mostly confined to preclinical studies.
Laboratory studies in human cell lines and animals show that noni extracts have anticancer effects both when used alone and with chemotherapy drugs. However, there is no proof from clinical trials that the same effect occurs in humans.
Regarding a Phase I dose-escalation clinical trial: in a Phase I study involving 51 patients with advanced cancers enrolled at seven dose levels of noni extract, the maximum tolerated dose was six capsules four times daily (12 g). Although no dose-limiting adverse events were found, seven of eight patients at the next level (14 g) withdrew due to the challenges of ingesting so many capsules. Furthermore, there was no evidence to indicate an optimal therapeutic dose or dosing interval.
5.3 Inflammation and Joint Health
Evidence strength: Preliminary human clinical evidence; animal and in vitro mechanistic data.
A review of published human intervention studies suggests that noni juice may provide protection against tobacco smoke-induced DNA damage, blood lipid and homocysteine elevation, as well as systemic inflammation. Human intervention studies also indicate that noni juice may improve joint health, increase physical endurance, increase immune activity, inhibit glycation of proteins, aid weight management, help maintain bone health in women, help maintain normal blood pressure, and improve gum health.
A critical caveat applies to all these human intervention findings: all the peer-reviewed human intervention studies to date have involved only one source of French Polynesian noni juice. Geographical factors and variations in processing methods are known to produce commercial noni juice products with divergent phytochemical and nutrient compositions. Therefore, other sources of noni products may have different toxicological and pharmacological profiles. Additionally, the authors of that review are employed in the research and development department of Morinda, Inc., a manufacturer of noni juice, representing a significant conflict of interest that limits the conclusions that can be drawn.
5.4 Immunomodulation
Evidence strength: Animal and in vitro only; limited human data.
Phytochemicals present in noni enhance the immune response and suppress inflammation; noni has shown the ability to reduce inflammation and tissue damage in ulcerative colitis with minimal side effects in experimental models, and has augmented anti-inflammatory mediators while significantly suppressing pro-inflammatory cytokines in mouse models. These effects remain to be confirmed in adequately powered human clinical trials.
5.5 Cardiovascular and Metabolic Effects
Evidence strength: Preliminary; no robust human RCT data.
The most popular medicinal uses for noni juice are in people with type 2 diabetes mellitus, heart disease, gastric ulcers, arthritis, menstrual cramps, depression, improved digestion, and cancer. However, most of these uses have not been studied.
5.6 Neuroprotection
Evidence strength: Preclinical only.
Given the role of oxidative stress in Parkinson's disease pathogenesis, scopoletin — an active principle from Morinda citrifolia — has been hypothesized to efficiently quench oxidative stress through DJ-1/Nrf2 signaling and ameliorate rotenone-induced PD in animal models. Despite reducing oxidative stress, administration of the extract also lessened protein aggregation as evident from decreased levels of nitrotyrosine and α-synuclein. These findings are preclinical and have not been validated in human trials.
5.7 Antimicrobial Activity
Evidence strength: In vitro only.
Among the biological activities of noni, antioxidant activity is particularly notable, with different extracts and isolated compounds demonstrating potent free radical scavenging capabilities. The antimicrobial potential against resistant bacteria, healing effects observed in animal models, and immunomodulatory properties further support the traditional therapeutic use of noni. These antimicrobial findings are based on laboratory experiments and have not been substantiated in human clinical studies.
6. Dosage Forms and Dosages Reported in Studies
The following dosages are those reported in identifiable studies and should be understood strictly in the context of the specific study protocols cited:
- Phase I cancer study (advanced cancer patients): Noni extract capsules at seven escalating dose levels; maximum tolerated dose was six capsules four times daily (12 g). Seven of eight patients at the 14 g level withdrew due to administration burden.
- Inflammatory marker study: In a study in which approximately 6,000–8,000 mg of noni extract was consumed daily, a significant reduction in systemic inflammatory markers was noted.
- Smoker antioxidant studies: Volunteers were divided into four dose groups: 0 mL (placebo), 30 mL, 300 mL, or 750 mL of noni juice daily for 30 days.
- DNA adduct study: Doses of one fluid ounce (29.5 mL) or four fluid ounces (118 mL) of noni juice per day over 30 days were associated with a 44.9% drop in aromatic DNA adduct levels (p < 0.001).
- Animal analgesic study: A 10% solution of freeze-concentrated noni fruit puree in the drinking water of mice reduced pain sensitivity comparably to tramadol. (Animal data only.)
It is recognized that further research is needed to clarify mechanisms of action and ensure safety for widespread application, and no universally accepted therapeutic dose for any human indication currently exists.
7. Safety Considerations and Drug Interactions
7.1 General Safety Profile
Limited assessment of safety has been carried out and there is a lack of high-quality studies, but few adverse effects have been reported after using noni and the fruit has been consumed as food for many years. Noni juice might be safe when used for up to 3 months.
7.2 Hepatotoxicity
A small number of isolated case reports of clinically apparent liver injury have been attributed to noni. In 2005, two published clinical case reports described incidents of acute hepatitis caused by ingesting Tahitian noni juice. These case reports were reviewed in 2006 by the European Food Safety Authority (EFSA), which initially reported that data were not sufficient to establish a causal relationship between consumption of the juice and hepatotoxicity; however, an increasing number of subsequent case reports suggested that some individuals may be particularly sensitive to hepatotoxic effects of noni fruit products.
One case involved a 29-year-old man with previous toxic hepatitis associated with small doses of paracetamol who developed sub-acute hepatic failure following consumption of 1.5 L of noni juice over 3 weeks, necessitating urgent liver transplantation. A second case involved a 62-year-old woman without evidence of previous liver disease who developed an episode of self-limited acute hepatitis following consumption of 2 L of noni juice for over 3 months.
Extracts of the noni fruit have multiple components, including low levels of anthraquinones which are often cited as being hepatotoxic. However, the cases of noni-associated liver injury have had all the characteristics of idiosyncratic liver injury rather than direct toxicity, and in vitro and in vivo studies of noni have not demonstrated evidence of intrinsic hepatotoxicity. Hepatotoxicity attributed to noni juice has occasionally been severe and led to acute liver failure, which in at least one case necessitated emergency liver transplantation.
After reviewing all available evidence, EFSA concluded that, on the basis of the available information, it is unlikely that consumption of noni juice at observed levels of intake induces adverse human liver effects. The U.S. National Center for Complementary and Integrative Health advised against consumption of noni products if one has a history of liver disorders.
7.3 Potassium Content and Renal Concerns
Some herbal products, including noni juice, contain undisclosed amounts of potassium, which can cause hyperkalemia. Caution is recommended in people with hyperkalaemia, kidney dysfunction, or those taking potassium-sparing diuretics or other drugs that increase potassium levels such as ACE inhibitors. The potassium content in some noni juice products may cause problems in people with renal insufficiency, on low potassium diets, or taking drugs likely to increase potassium levels.
7.4 Drug Interactions
- Warfarin/anticoagulants: One case has been reported of resistance to the anticoagulant coumadin, due to the vitamin K content of the particular noni product used by the patient. There is a theoretical risk of reduced warfarin effects.
- Potassium-sparing diuretics and ACE inhibitors: Patients taking potassium-sparing diuretics, angiotensin converting enzyme (ACE) inhibitors, or angiotensin receptor blockers should exercise caution, as noni can have additive effects on potassium levels.
- Antiepileptic drugs: Noni juice may decrease blood levels of phenytoin. This could reduce the effects of phenytoin and increase the risk of seizures.
- Chemotherapy and radiation: Noni has antioxidant effects and can theoretically interfere with chemotherapy or radiation treatment. Clinical relevance is not known.
7.5 Pregnancy and Lactation
Toxicity tests in animals have found conflicting evidence of toxicity from noni juice to developing embryos and fetuses. In addition, large amounts of the fruit have been reported to cause an abortion, and historically noni root bark has been used as an abortifacient, indicating it may be unsafe in pregnancy. It is recommended that it be avoided in pregnancy and lactation.
7.6 Overall Evidence Gaps
Although evidence of its beneficial effects is growing, further clinical studies and standardization of extracts are necessary to ensure its safe and effective use in medical practice. Further pharmacological and toxicological studies, in addition to well-designed controlled clinical trials, are needed to validate noni as an effective and novel natural product for prophylactic and therapeutic use in several diseases.
References
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