Borassus Palm (Borassus flabellifer L.)
1. Identity: Botanical Classification, Names, and Natural Source
Scientific Name and Taxonomy
The scientific name of Palmyra palm is Borassus flabellifer, derived from the Greek word Borassus, meaning leathery fruit, and flabellifer, meaning fan-shaped leaves. Borassus flabellifer is a slow-growing, monocot, and dioecious plant with chromosomal number 2n = 36, belonging to the family Arecaceae. A synonym of long standing is Borassus flabelliformis L.
Common Names
Borassus flabellifer, commonly known as doub palm, palmyra palm, tala, tal palm, toddy palm, lontar palm, wine palm, or ice apple, is a fan palm native to South Asia — especially in Bangladesh, East India, and South India — and Southeast Asia. Other common names include Sugar palm, Asian Palmyra palm, Fan palm, Cambodian palm, Kerigi, Mak tan kok, Borassus palm, and Taan.
Morphology and Natural Distribution
Borassus flabellifer, commonly called palmyra palm, toddy palm, or lontar palm, is a large fan palm that typically matures to 60 feet tall and 25 feet wide, featuring a straight solitary gray trunk (to 3 feet in diameter) ringed with leaf scars and a globose crown of rigid palmate leaves (each 8–10 feet long) with spiny stalks. The tree can grow to a height of 30 m and can live up to 150 years. Like all Borassus species, B. flabellifer is dioecious, with male and female flowers on separate plants.
It is difficult to determine the original habitat of B. flabellifer as its distribution is so heavily influenced by human activity. It occurs between sea level and 800 metres, and is more abundant at low altitude, particularly common in coastal areas with sandy or alluvial soils and in areas with permanent soil moisture such as flood plains and river valleys.
Cultural Significance
The palmyra tree is the official tree of Tamil Nadu. Highly respected in Tamil culture, it is called "katpaha tharu" ("celestial tree") because all its parts have a use. The palmyra is also prominently featured on the official emblem of Sri Lanka's Northern Province as a symbol of strength and the traditional livelihood of the people. The Asian palmyra palm is a symbol of Cambodia, where it is very common and found all over the country.
Commonly Used Parts and Preparations
The entire plant — root, trunk, leaves, inflorescence, sap, fruit pulp, and seed — is used in food, medicine, and material culture. Key preparations include:
- Palm sugar (jaggery) and sap syrup: The inflorescence produces a sugar-rich sap that can be drunk fresh or processed into a sweet syrup or solid palm sugar (jaggery).
- Neera / Pathaneer: Palmyra palm sap, known as "neera" or "pathaneer" in Tamil, is collected by tapping palmyra inflorescences. Fresh sap is a nutritional beverage, transparent, colorless, and of low viscosity.
- Fruit pulp and kernel: The immature endosperm (tender kernel) is eaten fresh, and the fruit pulp is consumed or incorporated into foods and beverages.
- Sprouted seedlings: Sprouted seedlings of Palmyra palm can also be eaten raw, cooked, or sun-dried for later consumption.
- Root decoctions, leaf extracts, and flower extracts used in traditional medicine.
- Palm granulated sugar: Palm granulated sugar is an important product from this widely-distributed tropical palm sugar-producing plant.
2. Traditional and Historical Use
South Asia: India, Sri Lanka, Bangladesh
For millennia, Borassus flabellifer has been used for food, drink, construction materials, and traditional medicine. Traditionally, different parts of the plant such as roots, leaves, fruit, and seeds have been used for various human ailments, and the leaves of this tree are used to make mats, baskets, fans, toys, and candy boxes.
Innumerable traditional medicinal uses are known for all parts of the toddy palm. The young plant is said to relieve biliousness, dysentery, and gonorrhea. Young roots are anthelmintic and diuretic. A decoction is given in certain respiratory diseases.
In the Ayurvedic and Siddha traditions of India, the sap was historically used as a tonic and stimulant. Heartburn and enlarged spleen and liver were treated using the ash of the flower. Sap from the flower stalk was used as tonic, diuretic, stimulant, laxative, amoebicide, and anti-phlegmatic, among other applications.
In folklore medicine, gastric problems and external wounds are controlled with palm leaf extract, while the sap is used as a natural laxative. The juice obtained from the flower stalk was used to treat diabetes.
In Sri Lanka, the dried seed shoot has long been ground into flour — known locally as "odiyal" — and consumed as a food and functional preparation, though this use carries specific safety considerations discussed later. The fruit pulp of B. flabellifer has been used in traditional dishes, and the sap has been used as a sweetener for diabetic patients.
Southeast Asia: Indonesia, Cambodia, Thailand
Lontar (Borassus flabellifer L.) is a species of the Palmae (areca) family commonly found in Indonesia. Lontar has many traditional benefits for people in Indonesia. The palm is known in Indonesia as "siwalan" or "lontar" and the sap is tapped for fresh consumption and fermentation into a mildly alcoholic beverage.
In Cambodia, palmyra palm is an important sugar-producing plant and its jaggery and sweet sap are prevalent as a substitute for table sugar.
As a traditional energizing drink with significant health-promoting effects, the fermented palm nectar (toddy) is enjoyed by people in parts of South America, Africa, and Asia. Local names include kallu in southern India, emu and ogogoro in Nigeria, nsafufuo in Ghana, and tuba in Mexico.
Traditional Uses by Plant Part (Summary)
- Roots: The young roots are taken as a diuretic and anti-parasitic drug, and decoctions prepared from these roots are used to treat respiratory and gastritis disorders.
- Flowers (ash): Heartburn and enlarged spleen and liver can be treated using the ash of the flower.
- Sap (toddy / neera): Used as a tonic, diuretic, laxative, and amoebicide; also consumed as a refreshing nutrient-rich beverage.
- Fruit: The fruit is commonly used in traditional medicine to alleviate digestive issues such as diarrhea and to manage symptoms of diabetes, with leaf juice taken orally for stomach problems.
- Leaf extract: Applied in folklore medicine for gastric problems and external wounds.
- Leaf secretions: The scaly secretions on the surfaces of the leaves of Asian palmyra palm differ from other plants; these secretions are used by traditional palmyra tree climbers to treat cuts or wounds inflicted by their tools during palm juice tapping.
3. Key Constituents and Active Compounds
Phenolic Compounds, Flavonoids, and Tannins
Phytochemical analysis of Borassus flabellifer fruit revealed the presence of several bioactive phytoconstituents such as flavonoids, phenol, alkaloids, saponins, tannins, and terpenoids. In various B. flabellifer extractions, numerous phytochemicals have been identified, including alkaloids, steroids, tannins, flavonoids, phenols, glycosides, coumarins, and saponins.
LC-MS/MS analysis of the male flower ethanolic extract revealed the presence of gallic acid, coumarin, and quercetin; concentrations of quercetin, coumarin, and gallic acid were 0.912, 0.021, and 1.610 µg/mL, respectively.
Steroidal Saponins: Flabelliferins and Borassosides
Phytochemical studies of the plant revealed the presence of spirostane-type steroid saponins; the steroidal glycoside also contains a bitter compound called flabelliferins. The male inflorescence constitutes borassosides and dioscin, spirostane-type steroid saponins.
These compounds are among the most pharmacologically studied constituents of the palm. The saponins designated flabelliferins (isolated from fruit pulp) and borassosides (isolated from male flowers) are structurally spirostane-type glycosides. The flabelliferins of palmyrah are of importance due to their significance in food as well as their bioactivity. There is a large number of flabelliferins in palmyrah fruit pulp and their separation is a challenge.
Alkaloids, Terpenoids, and Fatty Acids
Preliminary phytochemical analysis reveals that the roots of Borassus flabellifer Linn. comprise carbohydrates, terpenoids, flavonoids, coumarins, alkaloids, tannins, saponins, cardiac glycosides, and proteins. GC/MS analysis reveals that ethanolic extracts from the roots of Borassus flabellifer are reported to have thirty-six bioactive compounds, each with unique significance. Key fatty acids identified by GC/MS include n-hexadecanoic acid (palmitic acid) and octadecanoic acid (stearic acid), along with phenol and D-mannose.
Vitamins and Minerals in Sap and Fruit
The fresh pulp is reportedly rich in vitamins A and C. The fresh sap is reportedly a good source of vitamin B-complex. The sap is also rich in minerals (sodium, potassium, phosphorus, iron, zinc, and copper) and vitamins (thiamine, riboflavin, pyridoxine, pantothenic acid, and nicotinic acid).
Detailed vitamin analysis of fruit pulp has shown: Thiamine was 0.523 µg, riboflavin 9 µg, pyridoxine 3.9 µg, and niacin 0.5 µg. Ascorbic acid content was 16.9 mg/100 g. The pulp contains a high amount of sodium (20 mg/100 g) followed by phosphorus (15 mg/100 g), magnesium (10.2 mg/100 g), copper (10 mg/100 g), and calcium (8.76 mg/100 g).
Palmyra palm syrup contained 10 vitamins, the most abundant being vitamin E. Overall, 38 volatile compounds were found and classified into six groups: alcohols, acids, ketones, sulfurs, pyrazines, and phenols/aldehydes.
Specific Sap Constituents
Palmyra palm sap contains 2,3,4-trihydroxy-5-methyl acetophenone, nicotinamide, and uracil. The 2,3,4-trihydroxy-5-methyl acetophenone has exhibited DPPH radical scavenging activity and antibacterial activity. Generally, the sap contains reducing and non-reducing sugars, ethanol, and various nutrients including volatile fatty acids (VFAs), amino acids, and flavonoids.
Seed Embryo Composition
The seed contains 71.5 g carbohydrates, 12.5 g protein, and 4.3 g fiber per 100 g dry matter. Mineral analysis shows high levels of potassium (68 mg) and calcium (48 mg) per serving, vital for human nutrition.
4. Scientific Evidence by Area of Use
4.1 Antidiabetic Activity
This is the most extensively investigated pharmacological area for B. flabellifer. The body of evidence is composed almost entirely of in vitro cell studies and animal models; no published human clinical trials have confirmed antidiabetic efficacy.
Animal (in vivo) studies: One study undertook to evaluate the antidiabetic effects of Borassus flabellifer fruit methanol extract (BF-M) on diabetic rats induced with High Fat Diet (HFD)/streptozotocin (STZ). When BF-M (100 or 200 mg/kg) was administered for 21 days orally, it led to a sharp decline in triglycerides, total cholesterol, free unsaturated fat, glucose-6-phosphate, fasting blood glucose, and fructose 1,6 bisphosphatase compared to diabetic control. BF-M also downregulated Protein Tyrosine Phosphatase 1B (PTP1B). BF-M significantly increased serum insulin, glycogen content, and body weight. Western blot analysis exhibited significant inhibition of PTP1B in pancreatic tissue, confirmed by histology and immunohistological studies.
In vitro enzyme inhibition: The enzymes α-amylase and α-glucosidase inhibitory activities were investigated. The ethanolic extracts of B. flabellifer exhibited high antioxidant activity towards DPPH, ABTS, FRAP, SO, and NO, and possessed the strongest inhibitory effect towards α-amylase and α-glucosidase. Inhibition of these carbohydrate-digesting enzymes represents a proposed mechanism for reducing postprandial glucose levels.
Antidiabetogenic saponins: New spirostane-type steroid saponins with antidiabetogenic activity were identified from Borassus flabellifer (Chem. Pharm. Bull. 2007; 55:308–16).
Glycemic index of palm sugar: The low glycaemic index of palmyra palm sugar makes it a suitable alternative for diabetic patients, while the sap is traditionally consumed as a refreshing and nutrient-rich beverage. However, no controlled clinical trials in human diabetic populations have established a therapeutic dose or efficacy endpoint.
Evidence strength: Preliminary; confined to animal models and in vitro systems. Human clinical evidence is absent.
4.2 Antioxidant Activity
Antioxidant properties of multiple plant parts have been studied consistently using standardized in vitro assays.
Phytochemical screening of leaf methanol extract revealed the presence of several phytochemicals; the extract showed dose-dependent radical scavenging activity with IC50 values of 40.19 µg/mL for DPPH and 30.92 µg/mL for H2O2 radicals. DPPH and ABTS antioxidant assays of B. flabellifer male flower extract indicated IC50 values of 31.54 ± 0.43 and 164.5 ± 14.3 µg/mL, respectively, and the FRAP assay revealed high ferric ion reducing power.
Palm granulated sugar exhibits a high total phenolic content (2.77–8.94 mg gallic acid equivalent/100 g), DPPH radical scavenging activity (20.15%–37.88%), and a FRAP value of 322.68–378.23 µmol Fe²⁺/mL.
A study of B. flabellifer haustorium extract found a total polyphenols and flavonoids content of 37.92 ± 4.03 mg gallic acid equivalent and 7.02 ± 0.61 mg quercetin equivalent. Pretreatment with the extract significantly reduced the cytotoxic effect of hydrogen peroxide and malondialdehyde (p < 0.01) in intestinal epithelial (IEC-6) cells, with restoration of cellular glutathione levels and catalase activity (p < 0.05).
Evidence strength: Consistent in vitro antioxidant activity across multiple assays and plant parts. No human trials confirm in vivo antioxidant efficacy.
4.3 Anti-inflammatory Activity
A study demonstrated that B. flabellifer haustorium extract dose-dependently reduced the LPS (1 µg/mL)-induced release of pro-inflammatory cytokines including IL-1β, IL-6, and tumor necrosis factor-alpha (TNF-α) in Raw 264.7 macrophage cells. The study concluded that Borassus flabellifer haustorium can be an efficient antioxidant and anti-inflammatory functional food.
At 250 and 500 µg/mL, the male flower ethanolic extract demonstrated the highest anti-inflammatory activity as assessed by the protein denaturation assay in that in vitro model.
Flowers of B. flabellifer were investigated for analgesic and antipyretic effects, anti-inflammatory activity, and haematological, biochemical parameters, as well as immunosuppressant property.
Evidence strength: Preliminary; based on in vitro cell-based systems and animal pharmacology. No randomized human studies have been conducted.
4.4 Antimicrobial Activity
The seed coat, root, and sap could inhibit the growth of bacteria and fungi such as Streptococcus mutans, Staphylococcus aureus, Candida albicans, Klebsiella pneumoniae, Escherichia coli, and Bacillus subtilis.
In a PubMed-indexed in vitro study of seed coat extracts: Preliminary phytochemical screening of the aqueous, methanolic, and ethanolic extracts of seed coat of B. flabellifer revealed the presence of tannins, flavonoids, saponins, glycosides, and terpenoids. The zone of inhibition of methanolic extracts varied from 16 to 23 mm, ethanolic extracts from 14 to 23 mm, and aqueous extracts from 10 to 15 mm at 50 mg/mL concentrations. Among all tested organisms, Aspergillus brasiliensis and Bacillus subtilis showed a higher rate of inhibition with ethanolic and methanolic extracts.
Borassus flabellifer sap is indicated against E. coli, Streptococcus aureus, Bacillus subtilis, and Klebsiella pneumonia, with a zone of inhibition between 8 to 24 mm at different volumes.
Against skin-relevant pathogens, the male flower extract was able to inhibit Cutibacterium acnes bacteria with a minimum inhibitory concentration (MIC) of 250 mg/mL.
Evidence strength: In vitro only. All published studies use agar diffusion or broth dilution assays with no clinical follow-up in humans.
4.5 Hepatoprotective Activity
Different parts of Borassus flabellifer are used as food and in traditional medicine. Hepatoprotective activity of B. flabellifer root extracts was studied on paracetamol-induced liver toxicity in rats; phytochemical analysis of the extracts showed the presence of sterols, terpenoids, glycosides, carbohydrates, proteins, flavonoids, alkaloids, phenols, tannins, saponins, and oils. Ethyl acetate, chloroform, and methanol extracts of B. flabellifer showed dose-dependent percentage protection against paracetamol-induced liver toxicity.
Evidence strength: Preclinical animal data only. Not assessed in human clinical trials.
4.6 Cytoprotection and Kidney Protection
Crude male flower extracts were investigated for their effects on antioxidant activity, maintenance of cellular redox, and mitochondrial function in cisplatin-induced kidney injury. The methanolic extract exhibited greater antioxidant activity than the ethyl acetate extract. Cytoprotective effect was demonstrated in both extracts, particularly in the ethyl acetate extract. The extracts showed protection against the cytotoxic effect of cisplatin by prevention of increased GSSG and declined GSH/GSSG ratio.
Additionally, a study published in Drug and Chemical Toxicology investigated the protective effect of Borassus flabellifer Linn. haustorium extract (BHE) against fluoride-induced intestinal redox metabolism and apoptosis.
Evidence strength: In vitro cell-line studies only.
4.7 Wound Healing
A preliminary study published in the Journal of the National Science Foundation of Sri Lanka (2007) investigated the effects of an antibacterial steroidal saponin from B. flabellifer fruit on wound healing. The scaly secretions on palmyra leaves are used by traditional palm climbers to treat cuts and wounds inflicted during palm juice tapping, and a study was performed to scientifically validate this traditional application and determine the pharmacological significance of palmyra secretion. Phytochemical investigation and biological properties including antimicrobial and wound-healing studies were conducted using standard procedures. Phytochemical investigation confirmed the presence of tannins, carbohydrates, protein, terpenoids, and reducing sugar.
Evidence strength: Very preliminary; limited to a small proof-of-concept study (reported as seven volunteers) and preclinical work.
4.8 Immunomodulatory Activity
The immunomodulatory effect was investigated in mice using ethanol extract from the flower at a concentration of 300 µg/mL for twenty-six days. Immunomodulatory activity of exopolysaccharides (EPS) produced by Leuconostoc mesenteroides strains isolated from palm (Borassus flabellifer L.) sap was also studied; two strains (N5 and N7) produced EPS that were given to BALB/c mice before infection by lipopolysaccharide (LPS). Flow cytometric analysis of spleen lymphocytes showed that some EPS were able to increase cytokine production (IL-2, INF-γ, and TNF-α) by CD4⁺ cells.
Evidence strength: Animal and in vitro only; no human immunological trials have been published.
4.9 Anthelmintic Activity
An investigation of the anthelmintic property of leaf extract extracted using methanol in Pheretima posthuma at a concentration of 10 mg/mL revealed that the extract has effective anthelmintic activity against Indian adult earthworms. This parallels the long-standing traditional use of the young roots as an anthelmintic agent.
Evidence strength: In vitro (earthworm model) only.
4.10 Palm Sugar Nutritional Profile and Glycemic Considerations
Palm granulated sugar contains 10 kinds of vitamins (mainly vitamin E 52.15–55.12 mg/100 g), 5-hydroxymethylfurfural (2.18 to 41.92 mg/100 g), and 38 volatile compounds belonging to the alcohol, ketones, pyrazines, acids, and phenols groups, and an aldehyde group. Palmyra fruit and sap are rich sources of essential vitamins, minerals, and antioxidants, including vitamin C, iron, calcium, and phenolic compounds. The low glycaemic index of its sugar makes it a suitable alternative for diabetic patients. This claim, while widely cited, has not been confirmed by controlled clinical dietary intervention studies.
5. Body Systems and Health Areas of Association
Based on peer-reviewed research, B. flabellifer preparations have been investigated in relation to the following body systems:
- Endocrine / Metabolic: Antidiabetic and antihyperglycemic effects via PTP1B downregulation, α-amylase and α-glucosidase inhibition; lipid-lowering effects in animal models.
- Gastrointestinal: Traditional use for diarrhea, gastritis, and constipation (laxative); in vitro cytoprotection of intestinal epithelial cells.
- Hepatic: Hepatoprotective activity against chemically induced liver toxicity in preclinical studies.
- Renal: Cytoprotective effects in cisplatin-induced kidney cell injury in vitro; traditional use as a diuretic.
- Immune: Immunomodulatory activity demonstrated in murine and in vitro models.
- Microbial defense: Broad-spectrum in vitro antimicrobial activity against bacterial and fungal pathogens.
- Integumentary (skin and wound healing): Preliminary evidence for wound healing and anti-acne (Cutibacterium acnes) applications via topical preparations.
- Respiratory: Traditional use for respiratory conditions via root decoctions; not substantiated by clinical research.
- Cardiovascular / Blood: The fruits of B. flabellifer showed antioxidant, anthelmintic, diuretic, antibacterial, immunomodulatory, and antimalarial properties. Haematopoietic uses have been reported in traditional practice.
6. Dosage Forms and Reported Study Dosages
No standardized therapeutic dose for any indication has been established in human clinical trials. The following dosages appear in the cited scientific literature as experimental doses used in animal or in vitro studies:
- Fruit methanol extract (BF-M) in STZ/HFD diabetic rats: 100 mg/kg or 200 mg/kg administered orally for 21 days led to reductions in fasting blood glucose, triglycerides, total cholesterol, and other metabolic parameters.
- Flower ethanol extract (immunomodulatory, mice): 300 µg/mL administered for twenty-six days.
- Leaf methanol extract (anthelmintic, in vitro): 10 mg/mL tested against Pheretima posthuma.
- Seed coat extracts (antimicrobial): Methanolic, ethanolic, and aqueous extracts tested at 50 mg/mL concentration in agar well diffusion assays.
- Male flower ethanolic extract (antimicrobial and anti-inflammatory): MIC against C. acnes was 250 mg/mL; anti-inflammatory activity was highest at 250 and 500 µg/mL.
- Male flower extract (antioxidant): DPPH IC50 of 31.54 ± 0.43 µg/mL and ABTS IC50 of 164.5 ± 14.3 µg/mL.
In traditional and food-based use contexts, preparations such as fresh sap (neera/pathaneer), palm sugar (jaggery), and immature fruit kernel are consumed freely as dietary constituents with no defined supplemental dose. Standardized extract dosages are not established for human use.
7. Safety Considerations
Palmyrah Flour (Odiyal): Documented Toxicity in Animal Models
The most significant and well-documented safety concern relates specifically to flour prepared from the seed shoot (called "odiyal" in Sri Lanka and "palmyrah flour" more broadly). Palmyrah flour, which has been consumed for centuries, has many reported toxic effects, including neurotoxicity, hepatotoxicity, immunosuppression, clastogenic, and mutagenic effects. These have been demonstrated primarily in animal models.
A review covering the history of the neurotoxic effect of palmyrah (Borassus flabellifer L.) found that the chemical nature of the active synergists are isomers of a spirostane tetraglycoside containing three rhamnosyl residues and one glucosamine. Importantly, neurotoxicity has not been reported in humans consuming palmyrah flour; it is hypothesized that this may be due to a species effect; the mode of processing flour and cooking palmyrah flour recipes containing these water-soluble and dry-heat-decomposable saponin primary amines; frequency of consumption; and the nutritive value of other dietary components.
One study interpreted that the nutritional status of the diet influences the manifestation of the neurotoxic effect; the effect is suppressed with a nutritious diet. Studies on blood enzyme levels of rats showed that aspartate aminotransferase was significantly affected by oral administration of organic solvent-free water and methanol:water (1:1) extractives (P = 0.023 and P = 0.0044, respectively).
It is hypothesized that the hepatotoxic syndrome reported previously is due to a collective effect of a number of biologically active compounds, most of which are water-soluble saponins, like neurotoxins.
Fruit Pulp: No Established Toxicity
While palmyrah fruit pulp is highly underutilized due to its bitterness, there is so far no evidence of its toxicity. The bitterness of the pulp is attributed to flabelliferins, which are also proposed as bioactive compounds of interest.
Haemolytic Activity of Saponins
Testing for haemolysis on human red blood cells showed that a newly isolated saponin from palmyrah was hyper-haemolytic, with a haemolytic index 37-fold that of flabelliferin B (F-B), which had been the previously reported steroidal saponin red blood cell haemolyser with the highest activity from palmyrah. This indicates that specific isolated saponin fractions from palmyrah can be haemolytic, a consideration relevant to the use of concentrated or purified saponin extracts.
Part-Specific Safety Profile
The safety profile differs substantially between plant parts and preparation methods. Fresh sap (neera), fresh fruit pulp, palm sugar, and the immature kernel are widely consumed as foods without reported human toxicity. The primary concerns are associated with seed shoot flour and concentrated saponin isolates, not with the sap, jaggery, or fresh fruit preparations that form the basis of most traditional use.
Absence of Formal Pharmacopeial or Regulatory Evaluation
Borassus flabellifer does not appear in current WHO monographs, European Pharmacopoeia, ESCOP monographs, or NIH Office of Dietary Supplements fact sheets as a formally evaluated therapeutic agent. No systematic reviews or Cochrane reviews covering human clinical trials of B. flabellifer as a dietary supplement have been identified. The totality of pharmacological evidence remains at the preclinical stage.
References
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