Indian bael

Indian Bael (Aegle marmelos): A Comprehensive Reference

1. Identity, Taxonomy, and Common Forms

Botanical and Chemical Identity

Aegle marmelos Linn, also familiar as Bael, belongs to the family Rutaceae and has been frequently utilized in the indigenous Indian system of medicine because of its diverse medicinal properties. India holds high regard for this critical medicinal herb, also called Bengal quince, Bilva, Indian quince, Golden apple, Holy fruit, Bel, Belwa, Sriphal, Stone apple, and Maredo. The accepted binomial name is Aegle marmelos (L.) Corr.Serr., belonging to the kingdom Plantae, order Sapindales, family Rutaceae, subfamily Aurantioideae, tribe Clauseneae, genus Aegle.

The subtropical fruit Aegle marmelos, commonly known as Bael, belongs to the Rutaceae family. Though being native to northern India, widespread cultivation is found in other parts of India as well as in Thailand, Bangladesh, Pakistan, Sri Lanka, and Burma.

In different languages bael is named differently: Bilva and Shivaphala in Sanskrit, Belo in Oriya, Bel in Assamese and Marathi, and Vilva marum in Tamil in India; Be Li in Sinhalese; Matoom in Thai; and Bela in Spanish.

Plant Parts Used and Common Preparations

Each part of the tree — root, bark, fruit, leaf, and flower — has therapeutic significance in Ayurvedic as well as other traditional medicinal systems in treating ailments. The health benefits of bael are not only limited to the edible portion (fruit), but also extend to non-edible portions (root, trunk, bark, leaf, flower, and seed) having comparable biologically active compounds.

Bael fruits are of dietary use, and the fruit pulp is used to prepare delicacies like murabba, puddings, and juice. The bael fruit can be used widely as powder, wine, preserve, jam, and juice, which can be very effective for patients with diabetes, oral-gastric ulcers, and cancer. The fruit is also consumed as raw or processed foods, including powder, leather, syrup, toffee, beverages, and preserve. To preserve and consume over the year, the fruit pulp is generally dried to form a sheet-like texture known as leather.

2. Traditional and Historical Use

Antiquity and Cultural Context

Bael has been utilized for over 5000 years by numerous ethnic populations living in the Indian subcontinent. The therapeutic potential of bael is mentioned in ancient Hindu sacred texts — the Rig Veda, Charak Samhita, and Yajur Veda.

A. marmelos has mythological significance in Hindu religion. The leaves of this sacred plant, vernacularly known as 'Tripatra', have been an essential component of the offerings to Lord Shiva, and hence the tree is extensively planted in temples, which could be a reason for its use in traditional medicinal practices in India.

Bael has a long history of use in traditional medicine across Southeast Asia, with roots in the ancient Indian traditional medicinal system — Ayurveda. Bael leaves hold a significant place due to their expansive use in Ayurveda, traditional Chinese medicine, and other indigenous healing systems.

Traditional Indications and Preparations

In the Ayurvedic system, all parts of the plant were employed for a wide range of conditions. In Ayurveda it has been used for the treatment of Atisara (loose stool), Pravahika (dysentery), Shoth (generalised or localised swelling), Gulma (localised gas in the abdominal region), Arsha (haemorrhoids), Grahani (irritable bowel syndrome), Pandu (anaemia), Shvasa (respiratory disorders), Hikka (hiccough), Kasa (cough), Parshwashula (pain in chest bilaterally), and Hritshula (cardiac problems).

The extract prepared by boiling the bark, leaves, or roots in water is useful as a laxative, febrifuge, and expectorant, and is also useful in ophthalmia, deafness, inflammations, catarrh, diabetes, and asthmatic complaints. The fruits are used in treating diarrhea, dysentery, stomach ache, and cardiac ailments.

Bael fruits are also used in the treatment of chronic diarrhea, dysentery, and peptic ulcers, as a laxative and to recuperate from respiratory affections in various folk medicines. Bael leaves juice is taken on an empty stomach early in the morning by diabetic patients, and it is said to reduce sugar levels in about a month.

3. Key Constituents and Active Compounds

Major Phytochemical Classes

The health-promotive and protective effect of bael fruit is accounted for by fibers, carotenoids, phenolics, terpenoids, coumarins, flavonoids, and alkaloids. The ethnomedicinal properties of Bael are owing to its ability to synthesize alkaloids, cardiac glycosides, anthocyanins, flavonoids, steroids, saponins, terpenoids, tannins, lignins, quinones, coumarins, proteins, carbohydrates, amino acids, reducing sugars, fats, and oils.

Diverse phytochemicals present in bael include marmelosin, marmelin, marmelide, psoralen, alloimperatorin, skimmianine, rutaretin, scopoletin, aegelin, fagarine, anhydromarmelin, limonene, betulinic acid, marmesin, imperatorin, luvangentin and auraptene, lupeol, cineole, eugenol, citral, and citronellal.

Coumarins identified include marmelosin, marmesin, marmin, imperatorin, and scopoletin, along with terpenoids, tannins, polysaccharides, and flavonoids. Bael leaves specifically contain γ-sitosterol, aegelin, lupeol, rutin, marmesinin, β-sitosterol, flavone glycoside, and phenylethyl cinnamamides.

Phytochemicals include various compounds such as alkaloids, flavonoids, and phenolic acids (including protocatechuic acid, gallic acid, and ellagic acid).

Notable Individual Compounds and Their Mechanisms

Marmelosin and Marmesin: Marmelosin and marmesin demonstrate anticancer potential through inhibitory interactions with HSULF-2, a sulfatase linked to tumor progression, via π-alkyl, π-sulfur, and hydrogen bonding.

Aegeline: Aegeline is an important constituent of A. marmelos leaves, possessing cardioactive and anti-hyperglycemic activities. It also stimulates glucose transport and improves insulin sensitivity of skeletal muscles through Akt and Rac1 signaling pathways. Aegeline's binding to MAO-A and iNOS suggests antidepressant properties.

Imperatorin: Imperatorin shows antibacterial action against S. dysenteriae by targeting Cu-Zn superoxide dismutase, leading to oxidative stress-induced cell death. Phytochemical constituents such as auraptene, imperatorin, luvangetin, and psoralen show promising pharmacokinetic profiles, and molecular docking analysis reveals imperatorin as the most effective binder to key enzymes, emphasizing its therapeutic potential against inflammation and oxidative stress-related disorders.

Anti-diabetic Compounds: Anti-diabetic activity has been attributed to compounds such as aegeline and citral, which inhibit DPP-4 through interactions with Glu205 and Glu206 residues, thus supporting glucose homeostasis. Quercetin and coumarins display DPP-IV inhibition, reinforcing their anti-diabetic effect.

Compounds for IBD: Through network pharmacological analysis, AKT1, SRC, MAPK3, MAPK1, EGFR, IL6, TNF, HSP90AA1, and CASP3 were identified as top hub targets relevant to bael's potential role in treating IBD. Aegeline, auraptene, bergapten, imperatorin, marmesin, and nodakenin were identified as potent compounds with higher binding affinity to PI3K, AKT, and EGFR.

Antifertility Constituents: Researchers have associated the antifertility effects of A. marmelos extracts to two phytochemicals — marmin and fagarine.

Furanocoumarins: In coumarins enrichment analysis, fractionation of the fruit pulp extract yielded 31.2% marmelosin, 8.9% marmesin, 4% psoralen, 2% scopoletin, 1.7% umbelliferone, and 0.72% aegeline among total coumarins.

Novel Alkaloids: Shahidine, an alkaloid with an oxazoline core, has been isolated as a major constituent from fresh leaves and showed activity against several Gram-positive bacteria. New alkaloids from the leaves were also reported, including halfordino, ethylcinnamamide, and marmeline. A series of phenylethyl cinnamides, including new compounds named anhydromarmeline, aegelinosides A and B, were isolated from Aegle marmelos leaves and found to be α-glucosidase inhibitors.

4. Scientific Evidence by Area of Use

4.1 Gastrointestinal Health — Antidiarrheal and Gastroprotective Activity

According to earlier reports, A. marmelos is effective in chronic cases of diarrhea due to the presence of large quantities of mucilage, which act as a demulcent. A. marmelos has also been shown to be effective in experimental models of irritable bowel syndrome and physiological diarrhea.

A PMC-indexed study evaluated the decoction of dried unripe fruit pulp of A. marmelos for its effect on various parameters of diarrheal pathogenicity, including adherence to and invasion of intestinal epithelium, and production and action of enterotoxins, to elucidate its mechanism(s) of action in infectious diarrhea.

Gastroprotective (animal model): Oral administration of methanolic extract of Aegle marmelos fruit (MEAM) at doses of 25, 50, 100, 250, and 500 mg/kg reduced gastric ulcer by 2.8%, 52.4%, 73%, 93%, and 93.98%, respectively, compared to 89.2% reduction by sucralfate (100 mg/kg). MEAM treatment significantly inhibited increases in gastric secretory parameters and prevented the reduction of enzymatic and non-enzymatic antioxidants after experimental ulcer induction.

Evidence quality: Predominantly in vitro and animal data. The antidiarrheal evidence base is the most established preclinically, but robust, large-scale human RCTs are absent.

4.2 Antidiabetic Activity

The antidiabetic effect of A. marmelos aqueous extract was evaluated in a study involving streptozotocin-induced diabetic rats. The results confirmed the antidiabetic effect of the extracts, as the plasma glucose level in diabetic rats was restored to normal levels. In studies on bark-derived compounds, decreases in serum glucose, glycated hemoglobin, glucose-6-phosphatase, and fructose-1,6-bisphosphate were observed alongside increases in plasma insulin and hexokinase activity, as well as increases in antioxidant enzymes (SOD, CAT, GPx) and decreases in MDA. There was also reduction in cholesterol, triglyceride, LDL, and VLDL levels, signifying antihyperlipidemic properties.

An in vitro study found that A. marmelos substantially inhibited the enzymes α-amylase and α-glycosidase, with IC50 values of 46.21 and 42.07 mg/mL, respectively. In HepG2 cells, A. marmelos significantly reduced ROS levels that were elevated due to high glucose and enhanced glucose consumption.

Human/Clinical Evidence: A randomized controlled trial compared the clinical efficacy of Aegle marmelos leaf juice (supplementation at 20 g/100 mL for 60 days) among type 2 diabetes mellitus subjects. Confirmed type 2 diabetes mellitus subjects (n = 60) were randomly divided into an experimental group (n = 30) receiving leaf juice and a control group (n = 30) for 8 weeks.

In a separately reported clinical trial, administration of 5 g bael leaf powder to twenty type-2 diabetic patients with postprandial blood glucose of 201 ± 6 mg/dL once daily for 16 weeks effectively reduced postprandial blood glucose to 159 ± 5 mg/dL. Another study reported that administration of 4 g bael leaf extract daily (2 g twice a day) along with sulfonylurea in non-insulin-dependent diabetes mellitus patients for eight weeks significantly decreased blood glucose and urinary glucose levels.

Evidence quality: There are a small number of human clinical studies, including at least one RCT, showing blood-glucose-lowering effects. Sample sizes are small and study designs vary. The existing preclinical evidence is substantial. Independent, large-scale clinical confirmation is needed before definitive conclusions can be drawn.

4.3 Antimicrobial Activity

A. marmelos is known to have antimicrobial properties due to its rich phytochemical constituents. Methanolic leaf extracts have shown potent antimicrobial activity against Gram-positive bacteria. Shahidine, an alkaloid having an oxazoline core, showed activity against several Gram-positive bacteria.

In the context of oral health, limonene from bael exhibits anti-Streptococcus mutans activity by binding to the SpaP protein, thereby interfering with bacterial adhesion.

Evidence quality: Evidence for antimicrobial activity is largely in vitro. Clinical data in human infections are lacking.

4.4 Anticancer and Radioprotective Activity

Scientific studies have validated many of Bael's ethnomedicinal properties, including antimicrobial, hypoglycemic, astringent, antidiarrheal, antidysenteric, demulcent, analgesic, anti-inflammatory, antipyretic, wound-healing, insecticidal, and gastroprotective properties. Studies have also shown that Bael and some of its phytochemicals possess antineoplastic, radioprotective, chemoprotective, and chemopreventive effects.

One new furanocoumarin, 3′-prenyloxypsoralen, and two known furanocoumarins, imperatorin and xanthotoxin, were isolated from the raw fruits of Aegle marmelos. The new compound exhibited moderate cytotoxic activity against HEK293, HeLa, MCF7, and HT29 cell lines with IC50 values of 31.2, 44.8, 36.3, and >50.0 μg/mL, respectively.

Marmesin and marmelosin interact with the heparan sulfatase-2 (HSULF-2) active site, which has been proposed as a potential mechanism for their antitumor effects.

Evidence quality: Anticancer evidence is restricted to in vitro and some animal studies. No clinical trials in human cancer patients have been identified from available sources.

4.5 Hepatoprotective Activity

From the findings of preclinical studies, results clearly indicated that the fruit of A. marmelos is effective in the treatment/prevention of hepato-cytotoxicity in model animals.

In a study assessing the hepatoprotective potential of A. marmelos against carbon tetrachloride-induced oxidative stress in male Wistar rats, it was demonstrated that glutathione (GSH), GSH reductase, GPx, quinone reductase, and CAT levels were decreased in toxin-treated controls, demonstrating the restoration of hepatic antioxidant status at various concentrations by the extract.

Treatment with A. marmelos (50 mg/kg) and its combination with piperine reduced severity of hepatic damage as compared to the CCl4-treated group. Vascular distortion and lymphocyte infiltration were also reduced, further confirming hepatoprotective effect.

Evidence quality: Evidence is restricted to animal models. No human hepatoprotection clinical trials have been identified in the available literature.

4.6 Anti-inflammatory and Antioxidant Activity

The flavonoids, tannins, and phenolic compounds that act as primary antioxidants and free radical scavengers are found to be maximum in the alcoholic extract of the fruit pulp. Various scientific reports suggested that A. marmelos and its bioactive constituents could play a vital role in the prevention of several chronic and degenerative diseases associated with oxidative stress.

Studies highlight A. marmelos's potential as a therapeutic agent due to its potent antioxidant and anti-inflammatory properties. Phytochemical constituents such as auraptene, imperatorin, luvangetin, and psoralen show promising pharmacokinetic profiles, and molecular docking analysis revealed imperatorin as the most effective binder to key anti-inflammatory enzymes.

Evidence quality: Largely in vitro and in vivo (animal) evidence. Anti-inflammatory human trials are absent in the available literature.

4.7 Neurological and Neuroprotective Activity

According to available research, Aegle marmelos extracts potentially have neuroprotective benefits due to their capacity to alter cellular mechanisms that cause neuronal damage.

Evidence quality: Very preliminary. The evidence is based on animal models, and no human neuroprotection trials have been identified.

4.8 Cardioprotective Activity

The hepatoprotective, cardioprotective, antidiabetic, and radioprotective potential of bael has been recorded by researchers. Aegeline is an important constituent of A. marmelos leaves, possessing cardioactive activities.

Evidence quality: Preclinical only. No human RCTs evaluating cardioprotection specifically have been identified.

5. Body Systems Associated with Indian Bael

• Gastrointestinal system: A. marmelos has antidiarrheal, antipyretic, ulcer-healing, and anti-inflammatory properties that have been extensively studied.
• Endocrine/metabolic system: Antidiabetic and antihyperlipidemic activities are documented in both animal models and preliminary human studies.
• Hepatic system: Hepatoprotective effects demonstrated in CCl4-induced toxicity animal models.
• Immune and antimicrobial: The plant has a plethora of bioactive compounds which account for its antibacterial, anti-inflammatory, antioxidant, antidiabetic, antidiarrheal, anticancer, diuretic, and antiulcer activity.
• Reproductive system: Evidence for reversible male antifertility effects from animal studies.
• Nervous system: Preliminary neuroprotective findings in animal studies.
• Cardiovascular system: Cardioactive alkaloids identified; preclinical evidence only.

6. Dosage Forms and Dosages Reported in Studies

In one clinical study, 5 g of bael leaf powder administered once daily for 16 weeks to type-2 diabetic patients was reported to reduce postprandial blood glucose.

In another reported study, 4 g of bael leaf extract daily (2 g twice a day) along with sulfonylurea in non-insulin-dependent diabetes mellitus patients for eight weeks significantly decreased blood glucose and urinary glucose levels.

In the Gujarat randomized controlled trial, leaf juice supplementation was given at 20 g/100 mL for 60 days (8 weeks) to 30 subjects in the experimental arm.

In an animal gastroprotection study, oral administration of methanolic extract of Aegle marmelos fruit (MEAM) was tested at doses of 25, 50, 100, 250, and 500 mg/kg, showing dose-dependent ulcer reduction.

For antifertility evaluation, a 50% ethanolic extract of Aegle marmelos leaves was fed orally to male albino rats at dose levels of 200 and 300 mg/kg body weight per day for 60 days.

In male antifertility studies, methanolic bark extract of Aegle marmelos at doses of 200, 400, and 600 mg/kg body weight was administered orally for 60 days.

In a rat antihypercholestrolemic study, normal rat groups were fed diets containing bael leaf extract at 125 mg and 250 mg for 60 consecutive days.

Note: The doses listed above are those reported in cited studies. No standardized human therapeutic dose has been officially established for any indication.

7. Safety Considerations and Interactions

General Safety Margin

A wide therapeutic window and a high therapeutic index value were obtained for the extracts from A. marmelos, establishing it as a drug with high margin of safety in preclinical models. A. marmelos leaf extracts did not induce toxicity across a range of doses (50, 70, 90, and 100 mg/kg body weight) in animal models. Even a dose of 250 mg/kg did not show any adverse effect in animal models.

Antifertility Effects (Male Reproductive)

Methanolic extracts of Aegle marmelos administered orally for 60 days at doses of 200, 400, and 600 mg/kg caused dose-dependent lowering of serum testosterone levels and reproductive organ weight. Acrosomal integrity, motility, density, and viability of sperm were all reduced. Histopathological examinations revealed elongated spermatid exfoliation, nuclear chromatin condensation, degeneration, and conspicuous gaps within the germinal epithelium, all of which indicated testicular cytotoxicity and necrosis.

An important observation was that the fertility could be completely restored after withdrawal of A. marmelos extract treatment; hence, the effects on fertility are reversible. These effects have been observed in animal studies and their relevance to human reproduction at typical dietary or supplemental intakes is not established.

CYP450 Enzyme Inhibition and Drug Interactions

A study aimed to evaluate the effects of bael fruit extract and its constituents on major drug-metabolizing Cytochrome P450 enzymes. Using pooled human liver microsomes (HLM), a methanolic extract of Aegle marmelos and three of its furanocoumarins (marmelosin, marmesinin, and 8-hydroxypsoralen) and one alkaloid (aegeline) were tested. The methanolic extract competitively inhibited CYP3A4 (IC50 = 5 µg/mL; Ki = 3.4 µg/mL) and non-competitively inhibited CYP1A2 (IC50 = 0.8 µg/mL; Ki = 0.5 µg/mL).

Marmesinin showed moderate inhibition of CYP3A4 and CYP1A2, while aegeline was a very weak inhibitor of CYP3A4 and showed no inhibition for CYP1A2. No significant inhibition of recombinant CYP2D6, 2C9, and 2C19 was seen with the extract or its constituents.

This was the first report of CYP3A4 and CYP1A2 inhibition by A. marmelos extract and one of its furanocoumarins, marmelosin. Further studies are warranted to determine if acute or prolonged use of bael fruit could affect the pharmacokinetics of drugs that are substrates of CYP3A4 or CYP1A2.

Aegeline — Regulatory Note

The U.S. FDA warned that certain commercial products containing aegeline were considered adulterated because the company did not provide evidence of safety. Non-synthetic aegeline is an alkaloid extract from leaves of the Asian bael tree (Aegle marmelos). This regulatory action was specific to the isolated, concentrated alkaloid being used in sports-supplement products and does not necessarily apply to traditional whole-plant preparations of bael.

Presence of Furanocoumarins (Psoralen)

Aegle marmelos fruit has been reported to contain psoralen among its valuable phytoconstituents. Psoralen is a known furanocoumarin associated with photosensitizing effects when sufficient concentrations reach the skin, a property widely described for this compound class throughout the Rutaceae family. Clinical evidence of photosensitivity specifically from standard bael consumption has not been identified in the available sources.

Limitations of the Overall Evidence Base

Although A. marmelos has been historically revered in Ayurvedic and Siddha systems for its wide therapeutic applications, its integration into modern clinical practice remains limited by insufficient translational data. This plant does indeed have pharmacological properties of interest; however, further extensive research is needed to establish a potential strategy that can balance the pharmacological and toxic effects of bael.

References

• Journal of Applied Pharmaceutical Science — Phytochemical and pharmacological profile of Aegle marmelos (L.) Correa: A comprehensive review (2026)
• PMC / Tandfonline — Phytochemical and biological review of Aegle marmelos Linn
• PubMed — Phyto-pharmacological Potential of Aegle marmelos (L.) for Neurological Disorders: Progress and Prospects
• PubMed — Aegle marmelos (L.) Correa (Bael) and its phytochemicals in the treatment and prevention of cancer
• ScienceDirect — In-depth pharmacological and nutritional properties of bael (Aegle marmelos): A critical review
• PubMed — Bioactive compounds of Aegle marmelos L., medicinal values and its food applications: A critical review
• ScienceDirect — Aegle marmelos (L.): An underutilized plant with incredible pharmaceutical and nutritional potential
• ScienceDirect — Phytochemistry and medicinal uses of the bael fruit (Aegle marmelos Correa): A concise review
• ScienceDirect Topics — Aegle marmelos overview
• ScienceDirect — Aegle marmelos leaf juice as a complementary therapy to control type 2 diabetes — Randomised controlled trial in Gujarat, India
• PMC — Aegle marmelos (L.) Correa: An Underutilized Fruit with High Nutraceutical Values: A Review
• PMC — Studies on the antidiarrhoeal activity of Aegle marmelos unripe fruit: Validating its traditional usage
• PMC — Aegle marmelos fruit extract attenuates Helicobacter pylori Lipopolysaccharide induced oxidative stress in Sprague Dawley rats
• PMC — Systematic Evaluation of Aegle marmelos-Derived Compounds: Potential Therapeutic Agents Against Inflammation and Oxidative Stress
• PMC — Aegle marmelos Leaf Extract Phytochemical Analysis, Cytotoxicity, In Vitro Antioxidant and Antidiabetic Activities
• PMC — Comprehensive chemo-profiling of coumarins enriched extract derived from Aegle marmelos (L.) Correa fruit pulp, as an anti-diabetic and anti-inflammatory agent
• PubMed — Reversible changes in the antifertility induced by Aegle marmelos in male albino rats
• PubMed — Suppression of fertility in male albino rats following the administration of 50% ethanolic extract of Aegle marmelos
• PMC — Antifertility activity of methanolic bark extract of Aegle marmelos (L.) in male Wistar rats
• PMC — Augmentation of hepatoprotective potential of Aegle marmelos in combination with piperine in carbon tetrachloride model in Wistar rats
• PubMed — Inhibition of CYP3A4 and CYP1A2 by Aegle marmelos and its constituents
• PMC — Therapeutic effect of Aegle marmelos fruit extract against DMBA induced breast cancer in rats
• PMC — Bael (Aegle marmelos) fruit-based effervescent tablet formulations: Impact on physicochemical properties, bioactive compounds, and sensory attributes
• ScienceDirect — Aegle marmelos (Bael): Nutritional, functional and nutraceutical significance
• Research Journal of Pharmacology and Pharmacodynamics — Therapeutic uses of Vilwa (Aegle marmelos) in Ayurveda with Pharmacological Evidence
• PMC — Phytochemical composition, antilipidemic and antihypercholestrolemic perspectives of Bael leaf extracts
• ScienceDirect — Phytochemical profile and pharmacological activity of Aegle marmelos Linn.
• Research Square — Exploring the bioactives and mechanism of Aegle marmelos in the treatment of Inflammatory Bowel Disease through network pharmacology and molecular docking