nuez de malabar

Malabar Nut (Justicia adhatoda / Adhatoda vasica): A Comprehensive Reference

1. Identity and Botanical Description

Names and Taxonomy

The accepted scientific name is Justicia adhatoda L., family Acanthaceae. The synonym Adhatoda vasica Nees is also widely used throughout the literature. The standardized English common name is "Malabar nut tree," and the recognized Ayurvedic names include vasa and vasaka. Other common names in use across South Asia include adulsa, arusha, adathodai, bakash, adalodakam, adusoge, addasaramu, and "lion's muzzle" or "stallion's tooth."

The name "Adathoda" derives from a Tamil phrase meaning "untouched by goats," reflecting the fact that grazing animals avoid the plant due to its extreme bitter taste. The common English name "Malabar nut" is a nod to the plant's origins along the Malabar Coast of India.

Botanical Description and Habitat

Justicia adhatoda is a handsome shrub that grows wild in plains, tea plantations, and roadsides, reaching a height of up to 2.5 m in India and Southeast Asia. The shrub bears 10–20 lance-shaped leaves 8–9 centimeters in length by four centimeters wide. They are oppositely arranged, smooth-edged, and borne on short petioles. When dried, they are of a dull brownish-green colour and are bitter-tasting. The flower has large, attractive, white petals streaked with purple on the lower lip. The fruit is a small capsule with four seeds.

The plant's native range spans Afghanistan, the Indian subcontinent (Bangladesh, India, Pakistan, Nepal, and Sri Lanka), Laos, Myanmar, and Vietnam, and it has been introduced elsewhere. It has also been introduced to Cuba, Ethiopia, Jamaica, Madagascar, and Sicily. The shrub grows on the plains of India and in the lower Himalayas, up to a range of 1,000 meters above sea level, and is also cultivated in other tropical areas; it grows well in low-moisture areas and dry soils.

Common Forms and Preparations

The leaves, roots, flowers, and bark of this plant are all used medicinally; the parts of the plant are commonly employed in the forms of decoction or powder, and the juice from the leaves is also frequently used. Vasaka syrup and Vasaka liquid extract are mentioned in the Indian Pharmacopoeia (1955). During the 20th century, scientific recognition of the plant grew, and Vasaka syrup and liquid extract appeared in the Indian Pharmacopoeia in 1955. The plant is used internally as teas, decoctions, tinctures, and capsules, and externally as a paste or topical application.

2. Traditional and Historical Use

Ayurvedic Tradition

Adhatoda vasica leaves have been used in Ayurvedic medicine for over 2,000 years to treat respiratory disorders. Ayurveda has its origins in the Rigveda (circa 3000 BCE) and Atharvaveda (1500 BCE), making the tradition more than 5,000 years old, and Vasa (Adhatoda vasica Nees) finds mention in those Vedic compendia.

In Ayurvedic medicine, malabar nut has been used for a multitude of disorders including bronchitis, leprosy, blood disorders, heart troubles, thirst, asthma, fever, and vomiting. The leaf (Vasaka) is prescribed in Ayurveda for malarial fever, fever caused by pitta and kapha, chronic fever, intrinsic hemorrhage, cough and asthma, leprosy, skin diseases, and piles.

In Hindu Materia Medica, there was a saying "that no man suffering from phthisis need despair as long as the Vasaka plant exists." This reflects the deep historical esteem accorded to the plant as a primary lung remedy in the Indian tradition.

Unani Medicine

Justicia adhatoda has long been part of traditional Ayurvedic (Indian) and Unani (Arab-European) medicine, with its roots, leaves, flowers, and bark all used in various preparations to treat ailments ranging from coughs to asthma. Within Unani medicine, four varieties were described based on flower colour: the black variety—bitter and tangy—was used for phlegmatic inflammations, colic, leprosy, and wounds; the white variety for teeth and hair, leprosy, and blood and phlegm impurity; the red variety for bilious colic, cough, and asthma; and the yellow variety for digestive weakness and blood impurity.

Siddha and Folk Traditions

A. vasica is widely distributed across South and Southeast Asia and is used in Ayurveda and Unani medicine as a therapy for human diseases such as respiratory ailments including asthma, bronchitis, and tuberculosis. Traditional medicine also uses certain plant components to treat asthma, sprains, colds, coughs, malaria, edema, sexual difficulties, arthritis, and rheumatism. In Sri Lanka, the plant is known and trusted as Adathoda and is a staple in traditional medicine.

Traditional Preparations

Traditional recipes include taking one tablespoon of leaf juice with honey internally for cough and bleeding; for excessive menstruation, juice of leaves 15 ml with 15 gm jaggery twice daily internally; and decoction of the whole plant with sugar internally for bleeding piles. For relief in asthma, dried leaves were smoked; a preparation made from vasaka flowers, known as gulk, was used to treat tuberculosis. The fresh leaf juice was also taken with honey and long pepper for cough and phthisis.

The plant's longevity and usefulness has also been recognized by the World Health Organization, which included it in its manual The Use of Traditional Medicine in Primary Health Care.

3. Key Constituents and Active Compounds

Primary Alkaloids

The plant is rich in alkaloids, flavonoids, tannins, and saponins, with vasicine and vasicinone as the primary bioactive compounds responsible for its therapeutic activity. The principal constituents of Vasaka are its several alkaloids, the chief one being vasicine. The leaves contain two major alkaloids, vasicine and vasicinone, whose pharmacological activities are well established.

Six different quinazoline alkaloids have been isolated from the leaves: vasicoline, vasicolinone, vasicinone, vasicine, adhatodine, and anisotine. Vasicine is found in the dried material of the plant and makes up over 1% of the plant's dried material; it is known for its ability to relieve oxidative stress and inflammation through the PI3K/AKT/mTOR signaling pathway.

Secondary Metabolites and Other Constituents

A. vasica has also been identified to contain several secondary metabolites, such as quercetin, kaempferol, and apigenin, that exhibit antioxidant, antimicrobial, anti-inflammatory, and immunomodulatory activities. Other alkaloids found abundantly in the leaves and roots include vasicinol, vasicinolone, and adhatodine; further constituents include triterpenes, flavonoids, alkanes, steroids, daucosterol, and β-sitosterol. The leaves are also rich in vitamin C and carotene and yield an essential oil. The plant also contains a non-volatile alkaloid vasicine, an organic acid adhatodic acid, sugar, gum, and salts.

Vasicine Content and Standardization

Total alkaloid content in leaf juice preparations varies widely by preparation method, from 0.3 mg/ml to 5.93 mg/ml, and vasicine content from 0.2 mg/ml to 5.64 mg/ml. The traditional bolus preparation method yielded the best quality juice, with the highest total alkaloids (5.93±0.55 mg/ml) and vasicine (5.64±0.10 mg/ml) content.

4. Mechanisms of Action

Bronchodilation and Airway Relaxation

The alkaloids vasicinone and vasicine have potent bronchodilator and antiallergic activity, and owing to these activities, A. vasica is effective in acute asthma conditions. An essential oil from the leaves of A. vasica showed airway smooth muscle relaxant property in the isolated guinea pig tracheal chain. Early research reported that vasicine itself can have a bronchoconstricting action, and that bronchodilator effects previously attributed to preparations containing it were partly ascribed to contamination by small amounts of vasicinone. More recent evidence has clarified that both alkaloids jointly contribute to airway effects at physiologically relevant concentrations.

Mucoactive and Expectorant Effects

With a long history as an expectorant in India, vasicine has been modified to form the derivative bromhexine, a mucolytic inhalant agent that increases respiratory fluid volume, dilutes mucus, and reduces its viscosity. Bromhexine, a derivative of the Adhatoda vasica plant, has been found to enhance the secretion of various mucus components by modifying the physicochemical characteristics of mucus; these changes increase mucociliary clearance and reduce cough. Amin and Mehta were the first to isolate vasicinone in crystalline form from the leaves of Adhatoda vasica; one of the derivatives of vasicinone is bromhexine hydrochloride (N-cyclohexyl-N-methyl-(2-amino-3,5-dibromo-benzyl)amine hydrochloride).

Anti-inflammatory and Antiallergic Mechanisms

Vasicine has been demonstrated to induce bronchodilation and tracheal muscle relaxation at lower concentrations, while exhibiting significant protective effects against histamine-induced bronchospasm in guinea pigs at higher concentrations. Vasicine analogs can reduce phosphorylation of STAT6 and expression of GATA3 in asthmatic mouse models; vasicine has also been shown to alleviate atopic dermatitis by inhibiting skin mast cell infiltration, reducing serum IgE levels, and suppressing the expression of cytokines such as IL-4, IL-5, IL-9, and IL-13.

Ambroxol, a widely used secretolytic agent developed from vasicine, was shown to inhibit IgE-dependent mediator secretion from human mast cells and basophils—the principal effectors of allergic inflammation; compared to vasicine, ambroxol showed a better effect in lowering basophil IL-4 and IL-13 secretions.

Antioxidant Mechanisms

Vasicine has demonstrated antimicrobial activity and antioxidant activity in ABTS scavenging assay (IC₅₀ = 11.5 μg/ml), ferric reducing power assay (IC₅₀ = 15 μg/ml), DPPH radical scavenging assay (IC₅₀ = 18.2 μg/ml), hydroxyl radical scavenging assay (IC₅₀ = 22 μg/ml), and hydrogen peroxide assay (IC₅₀ = 27.8 μg/ml).

Uterotonic Mechanisms

The major alkaloid vasicine has been found to be biologically active; around 1977, it was discovered that vasicine possesses uterine stimulating activity with similar effect to oxytocin. After this discovery, and due to the great need for new drugs for fertility regulation, considerable research effort was devoted to developing vasicine as an abortifacient agent. The uterotonic and abortifacient potential of vasicine is probably due to the synthesis and release of prostaglandins; the dosage and action are dependent on the stage of pregnancy.

5. Scientific Evidence by Area of Use

5.1 Respiratory Disease: Cough, Bronchitis, and Asthma

Preclinical (animal/in vitro) evidence: In vivo and in vitro studies have shown that leaf extracts of A. vasica have expectorant, bronchodilator, anti-inflammatory, antitussive, and antimicrobial activities. Quinazoline alkaloids vasicine, vasicinone, and deoxyvasicine have demonstrated significant antitussive, expectorant, and bronchodilating activities in animal models. Specifically, at the highest doses tested (45 mg/kg), they showed antitussive activities similar to codeine phosphate (30 mg/kg) in mice and guinea pigs. Bronchodilation tests showed that vasicine, vasicinone, and deoxyvasicine prolonged pre-convulsive time by 28.59%, 57.21%, and 29.66%, respectively, at a dose of 45 mg/kg in guinea pigs, whereas aminophylline prolonged the pre-convulsive time by 46.98% compared with pretreatment.

A methanolic extract from the whole plant showed antiallergic and antiasthmatic properties in the guinea pig. AV has been demonstrated for its antitussive activity as effective as codeine in irritant-aerosol and citric acid–induced cough models.

Clinical (human) evidence: Direct clinical trials with Justicia adhatoda plant preparations in humans for respiratory conditions are limited and of variable methodological quality. A clinical trial was conducted with bromhexine (a derivative of the plant's active alkaloid) in 30 patients suffering from different respiratory symptoms. A significant change in the viscosity and acid mucopolysaccharide (AMPS) structure was found in the bromhexine-treated group compared to placebo, in both infected and noninfected patients. However, principal clinical research studies on bromhexine were primarily developed in an era when stringent methodological approaches and good clinical practices were not yet developed; clinical studies were conducted mainly in patients with chronic bronchitis and in patients with various respiratory diseases, and demonstrated efficacy of bromhexine in improving respiratory symptoms.

Limitations: Adhatoda vasica research reveals limitations that prevent its wider utilization, including insufficient clinical studies, non-standardized dosages, uncertain molecular mechanisms, challenges with bioavailability, bitter taste, and toxicity concerns. Clinical trials are needed to validate the effectiveness of these herbs, and randomized trials with adequate sample sizes are recommended to establish robust evidence. The evidence for the whole plant preparation in human respiratory disease, while biologically plausible, remains predominantly preclinical and traditional; the clinical evidence base is largely indirect, derived from studies of the semi-synthetic derivative bromhexine rather than from standardized J. adhatoda extract itself.

5.2 Tuberculosis and Antimicrobial Activity

Antitubercular activity of the plant extracts and vasicine derivatives has been observed in research settings. Activity of bromhexine and ambroxol—semisynthetic derivatives of vasicine from Adhatoda vasica—against Mycobacterium tuberculosis in vitro was reported in the Journal of Ethnopharmacology (1996). Vasicine (pegamine), found in leaves, roots, and flowers, has demonstrated antibacterial, antidiabetic, antitubercular, antimalarial, anti-inflammatory, and anti-carcinogenic properties in research studies. The leaf extract showed the highest antibacterial activity against E. coli in one study, with the lowest activity observed against Listeria.

This antimicrobial and antitubercular evidence is largely preclinical (in vitro and animal). No large-scale controlled human clinical trials confirming the plant's efficacy against active tuberculosis infections independent of standard medical treatment are available in the reviewed literature.

5.3 Anti-inflammatory and Analgesic Activity

The leaf extract of J. adhatoda revealed promising anti-inflammatory, analgesic, and antioxidant activities both in vitro and in vivo; the detected compounds also portrayed variable pharmacokinetic and binding affinities with target proteins. The characteristic alkaloids of J. adhatoda have demonstrated anti-inflammatory properties, and vasicinone has also shown anti-cholinesterase activity. This evidence is currently confined to in vitro assays and animal models; robust human clinical trial data for anti-inflammatory indications are not established.

5.4 COVID-19 / Antiviral Activity

A three-armed, open-labeled, randomized clinical trial was undertaken from November 2020 to September 2021. A total of 150 COVID-19-positive patients with no to mild symptoms, aged 19–65 years, were enrolled; 136 patients completed the study with RT-PCR negative reports. Patients received herbal drugs orally: Group A received Adhatoda vasica (AV) at 500 mg; Group B received Tinospora cordifolia (TC) at 500 mg; and Group C received AV + TC at 250 mg each, for 14 days. Clinical symptoms, vital parameters, and viral clearance were taken as primary outcomes, while biochemical, hematological parameters, cytokines, and biomarkers were evaluated as secondary outcomes. The plant has also demonstrated antiviral activity against the influenza type-B virus through its extracts. This single open-label trial has significant methodological limitations, and results require confirmation in larger blinded trials.

5.5 Anticancer Activity

The in vitro anticancer potential of J. adhatoda leaf extract was explored in one study: a methanolic extract was prepared and phytochemicals and antioxidant potential were analyzed by LCMS and DPPH radical scavenging assay; a docking study with five major alkaloidal phytoconstituents showed good binding affinity towards the active site of NF-κB; cell viability assay across five cell lines showed the highest cytotoxicity in MCF-7, a breast cancer cell line; extract-treated cells showed a significant increase in nitric oxide and reactive oxygen species production; and cell cycle analysis showed an arrest in cell growth at the Sub-G0 phase.

A549 human lung carcinoma cells treated with various doses of vasicinone (10, 30, 50, 70 µM) for 72 hours showed a significant decrease in cell viability; vasicinone treatment also showed DNA fragmentation, LDH leakage, and disruption of mitochondrial potential, along with lower wound healing ability in A549 cells. All anticancer evidence for this plant is currently in vitro (cell culture). No human clinical data exist.

5.6 Hepatoprotective Activity

Bioactive phytochemicals such as alkaloids, essential oil, flavonoids, quinazoline, tannins, and vasicinone present in several extracts of Adhatoda vasica may be responsible for potential hepatoprotective activity, according to experimental data. This evidence is confined to preclinical models; no controlled human trials have been identified in the reviewed sources.

5.7 Uterine Activity

Studies on human subjects have shown that the alkaloid vasicine has significant uterotonic activity. Both in vitro and in vivo studies on the possible abortifacient activity have been investigated using rats, guinea pigs, hamsters, rabbits, and human myometrial strips; an investigation carried out on human volunteers with IV injection of vasicine indicated that the uterus became firm and contracted after vasicine treatment, indicating its effectiveness as an oxytocic. In the 1980s, the WHO also included A. vasica in the Special Programme of Research in Human Reproduction as a plant worthy of study for fertility regulation.

6. Body Systems and Health Areas of Association

• Respiratory system: The leaves, roots, flowers, and bark of this plant have been used in the treatment of cough, colds, asthma, to liquefy sputum, as a bronchodilator, for bronchial catarrh, bronchitis, and tuberculosis.
• Immune and inflammatory system: Secondary metabolites such as quercetin, kaempferol, and apigenin exhibit antioxidant, antimicrobial, anti-inflammatory, and immunomodulatory activities.
• Reproductive system: Extensive research has explored the plant's antiasthmatic, antitussive, antioxidant, hepatoprotective, antiulcer, uterotonic, and abortifacient activities.
• Cardiovascular system: Vasicine produces a slight fall of blood pressure, followed by a rise to the original level, and an increase in the amplitude of heart beats and a slowing of the rhythm.
• Hepatic (liver) system: The plant has been studied for its antioxidant, hepatoprotective, anti-inflammatory, antibacterial, antiprotozoal, hypolipidemic, antiasthmatic, and abortifacient properties.
• Integumentary (skin) system: A poultice of the leaves may be applied to wounds for their antibacterial and anti-inflammatory properties.
• Oral health: Local use gives relief from pyorrhea and bleeding gums.

7. Dosage Forms and Dosages Reported in Sources

Traditional Ayurvedic doses documented include: leaf juice 10–20 ml; root decoction 40–80 ml; flower juice 10–20 ml; leaf dry powder 1–3 grams once or twice a day; Vasa Putapaka Swarasa (juice extract by the Putapaka method) 24–48 ml once or twice a day; and Vasa Ghrita (herbal ghee preparation) 5–10 grams once or twice a day before food.

In one pharmacopeial reference, the following dosages are cited: powder 3 g, decoction 3 to 9 ml; the extract of the leaves is today found only in some combination preparations, with a daily dosage of 1 to 2 g as drug or liquid extract (1:1) with 40% ethanol.

In the human randomized clinical trial on COVID-19 patients, patients in the Adhatoda vasica monotherapy arm received 500 mg orally for 14 days.

The drug is contraindicated in pregnancy across pharmacopeial references.

8. Safety Considerations and Notable Interactions

Uterotonic and Abortifacient Risk in Pregnancy

Adhatoda vasica has abortifacient and uterotonic properties, making it capable of inducing abortion and stimulating uterine contractions to speed childbirth. Animal model studies using rats, hamsters, rabbits, and guinea pigs revealed that vasicine operates similarly to oxytocin and ergometrine in these models. It showed an abortifacient effect in guinea pigs depending on the stage of pregnancy and prior estradiol priming; in rats it did not show any abortifacient effect. The abortifacient effect of vasicine, like its uterotonic effect, was more marked under the priming influence of estrogens, evidently indicating that the action of vasicine was mediated through prostaglandin release.

Up to the time of the critical ethnopharmacological and toxicological review (Claeson et al., 2000), many scientific publications regarding the oxytocic action of vasicine had appeared, and this led to important questions concerning the overall safety of A. vasica. The compound's uterotonic activity has also been demonstrated in studies on human myometrial tissue, making avoidance during pregnancy a well-supported precaution.

Pharmaceutical Derivative Safety Record

One immediate advantage of repurposing or further researching bromhexine, ambroxol, and their parent plant is that they are already known quantities with excellent safety records. Since its introduction to the market in 1963, bromhexine has been investigated for its activity in animal models and in humans with diverse respiratory conditions.

Variability of Alkaloid Content by Preparation Method

Commercially, manufacturers have adopted different methods for preparing the juice of Vasaka other than the traditional method; efforts to evaluate these modified processes revealed significant variation in the alkaloid content across preparation methods. Total alkaloid content varied from 0.3 mg/ml to 5.93 mg/ml and vasicine content from 0.2 mg/ml to 5.64 mg/ml in juice samples prepared by different methods. This wide variation has direct implications for dosage consistency and safety.

Evidence Gaps and Limitations

Despite promising pharmacological findings, challenges such as bioavailability and clinical validation remain; future research should focus on in vivo studies and standardized formulations to establish the efficacy of these compounds. Resolving these gaps with more thorough clinical trials, better formulations, and regulatory compliance will be necessary to increase the plant's medicinal potential and economic viability.

References

• AHPA Botanical Identity References Compendium: Justicia adhatoda (leaf)
• Bentham Science Publishers: The Multifaceted Potential of Adhatoda vasica Nees: Traditional Uses, Pharmacological Activities and Biotechnological Applications (2026)
• Wikipedia: Justicia adhatoda
• ScienceDirect Topics: Justicia adhatoda — Overview
• ScienceDirect Topics: Vasicine — Overview
• PMC: A reappraisal of the mucoactive activity and clinical efficacy of bromhexine (2017)
• PMC: Adhatoda vasica and Tinospora cordifolia extracts ameliorate clinical and molecular markers in mild COVID-19 patients: a randomized open-label three-armed study (2023)
• PMC: In Vitro Anticancer Activity of Methanolic Extract of Justicia adhatoda Leaves with Special Emphasis on Human Breast Cancer Cell Line (2022)
• PMC: Anti-Proliferative Activities of Vasicinone on Lung Carcinoma Cells (2018)
• PMC: Validation of Different Methods of Preparation of Adhatoda vasica Leaf Juice by Quantification of Total Alkaloids and Vasicine (2010)
• PMC: Phytochemical Characterization and Assessment of Crude Extracts from Justicia adhatoda for Phytotoxic and Cytotoxic Activity (2024)
• PubMed: Antitussive, expectorant, and bronchodilating effects of quinazoline alkaloids (±)-vasicine, deoxyvasicine, and (±)-vasicinone from aerial parts of Peganum harmala L. (2015)
• PubMed: Vasicine, alkaloid of Adhatoda vasica, a promising uterotonic abortifacient
• PubMed: Investigation of anti-inflammatory and anti-cancer activity of Justicia adhatoda metabolites (2019)
• PubMed: Anti-inflammatory and analgesic potential of leaf extract of Justicia adhatoda L. (Acanthaceae) in Carrageenan and Formalin-induced models (2022)
• ScienceDirect: Adhatoda vasica: a critical review of ethnopharmacological and toxicological data (Claeson et al., 2000)
• ScienceDirect: Identification of hydroxyquinazoline alkaloids from Justicia adhatoda L. leaves with NF-κB and AP-1-mediated anti-inflammatory properties (2024)
• Nature: Bronchodilating Action of Vasicinone and Related Compounds (Cambridge, Jansen & Jarman, 1962)
• PMC: Vasicine Attenuates Allergic Asthma by Suppressing Mast Cell Degranulation and Th2 Inflammation via Modulation of the FcεRI/Lyn + Syk/MAPK Pathway
• MDPI: An Overview of Justicia adhatoda: A Medicinal Plant but Native Invader in India (2025)
• LGC Standards: Pharmaceutical Roots — Justicia Adhatoda
• ResearchGate: Ethnopharmacological uses, phytochemistry, pharmacological activities and toxicity of Justicia adhatoda L.: a review (2024)
• ResearchGate: Adhatoda vasica: A critical review of ethnopharmacological and toxicological data (Claeson et al., 2000)
• Journal of Chemical and Pharmaceutical Research: Indian traditional herbs Adhatoda vasica and its Medicinal Application (2010)
• IJARSCT: Medicinal Importance of Justicia adhatoda in Traditional Medicine
• SpringerLink: Justicia adhatoda L. (Acanthaceae) — Chapter
• PMC: Valorization of Adhatoda vasica leaves: Extraction, in vitro analyses and in silico approaches (2023)