Lebbek

Lebbek (Albizia lebbeck (L.) Benth.): A Comprehensive Reference

1. Identity and Botanical Classification

1.1 Nomenclature

Albizia lebbeck (L.) Benth., commonly known as the lebbek tree or woman's tongue tree, is a fast-growing deciduous species of the family Fabaceae, native to tropical and subtropical regions. The species was first described by Carl Linnaeus and formally placed in the genus Albizia by George Bentham. It is also referenced historically under the synonym Acacia lebbeck, and the older spelling Albizzia lebbeck (with a double "z") appears widely in older scientific literature.

The species Albizia lebbeck (L.) Benth. (Family: Fabaceae) is commonly known as Siris or Shiris in Hindi, Lebbeck Tree in English, and Bhandi, Sitapuspa, Sukapriya, and Mrdupuspa in Sanskrit. It is also called Shirish in Bengali, vagei in Tamil, and sultanaulasjar in Arabic. In English, additional vernacular names include flea tree, frywood, woman's tongue tree, and acacia tree. It is also known as Indian siris and Laback in Arabic.

1.2 Botanical Description and Distribution

It is a deciduous tree that is mostly found in gardens or along roadsides and grows from sea level to 1,500 m elevation, attaining a height of up to 18 m. The trunk ranges in diameter from 50 cm to 1 m. Each pod has six to twelve seeds inside and measures between 15 and 30 cm in length and 2.5 and 5 cm in width. Flowers are white or yellowish white in color and highly fragrant.

It is mainly distributed in tropical and subtropical areas of India, the Andaman Islands, Myanmar, tropical Africa, Asia, and northern Australia. It grows naturally in Nepal, Bangladesh, Myanmar, and Pakistan and has been cultivated in tropical and subtropical regions in Northern Africa, the West Indies, South America, and South Asia.

1.3 Plant Parts Used and Common Preparations

Albizia lebbeck is an Ayurvedic plant that has been widely utilized in the treatment of anorectal, eye, gastrointestinal, genital, inflammatory, neurological, oral, respiratory, skin, and urinary disorders and venereal diseases across the world. Different parts of the plant have been used, but bark appears to be the most often used plant part in traditional medicine. In Ayurveda, bark, leaves, seeds, and flowers are all employed medicinally — each having distinct roles.

Common preparations include decoctions (water extracts of the bark), ethanolic and methanolic extracts, powders of the dried bark or seeds, fresh juice, and pastes applied topically. Albizia is used as a decoction, tincture, powder, or paste.

2. Traditional and Historical Use

2.1 Ayurveda (India)

Albizia lebbeck is a widely used medicinal tree in traditional Indian medicine, particularly in Ayurveda, Unani, and Siddha systems. In classical Ayurvedic texts such as the Charaka Samhita and the Sushruta Samhita, Shirisha is hailed as one of the top five herbs in the group called "Shirovirechana" — nasya drugs used for cleansing the head. The Ayurvedic Pharmacopoeia of India has formally monographed the plant as an official drug.

Traditionally, it is used in Ayurveda under the name "Shirisha" and is considered one of the best anti-poisonous herbs. It is extensively used to treat respiratory issues, especially allergic rhinitis and bronchial asthma. The plant is also credited with wound healing, anti-inflammatory, and anti-helminthic properties.

Traditionally, it is used as anti-asthmatic, anti-inflammatory, anti-fertility, anti-diarrhoeal, antiseptic, anti-dysenteric, and anti-tubercular. It is also used in the treatment of ringworms and wounds by washing affected areas, gonorrhea, leucorrhoea, bronchitis, leprosy, paralysis, helminth infection, and other genital diseases.

Albizia lebbeck bark powder was commonly mixed with cow's milk or honey and taken as an antidote for insect or snake bites in ancient rural India. Its flower is squeezed and juice extracted, triturated with black pepper and sugar, and used for nasal instillation and oral intake in snake bites, as described in the Charaka Samhita.

Classical Ayurvedic compound formulations containing Shirisha (lebbek) include Dashang Lepa, used in wounds and eczema; Ayaskriti, used in obesity, anemia, and vitiligo; and Brihat Marichadi Taila, used in lower back ache and spondylosis. It is still used in modern Ayurvedic formulations such as Shirishavaleha and Shirisha churna.

2.2 Unani Medicine

In the Unani system, Albizia lebbeck — referred to as "Siris" — was considered an effective detox herb for its supposed ability to neutralize poison and purge phlegm. The plant is described in classical Unani references under the name Siras and is employed specifically for its anti-asthmatic, anti-inflammatory, and anti-diarrhoeal properties within that tradition.

2.3 Sri Lankan and Broader Asian Traditional Medicine

In Sri Lankan traditional medicine, it was boiled into a decoction for asthma-like symptoms. A. lebbeck has been used in various countries of Africa, Asia, and Australia for the prevention of scabies, lung ailments, piles, bronchitis, abdominal tumors, cough, eye disorders, and so on.

2.4 African Ethnobotanical Use

During ethnobotanical surveys in Northern Cameroon, Albizia lebbeck was claimed by the local population to treat dysentery, asthma, hemorrhoids, bronchitis, eczema, leprosy, human fertility disorders, and diarrhea.

2.5 Traditional Uses: Summary Table by Organ System

• Respiratory: Traditionally used to cure asthma, cold, and cough.
• Gastrointestinal: Traditionally used to cure fever, diarrhoea, and dysentery.
• Ophthalmic: Traditional use in conjunctivitis.
• Dermatological: Traditionally used for skin disease and arthritis.
• Dental: An Ayurvedic kashaya (decoction) of its bark is used as a gargle for antimicrobial cleansing of the buccal cavity, and the stem/twig has been used from ancient times for brushing teeth.
• Neurological: Traditionally used in cases of headaches, sinus congestion, epilepsy, and even memory disturbances.
• Reproductive/Fertility: Used in the treatment of gonorrhea and leucorrhoea. Indians use the flowers for spermatorrhea.
• Anti-toxic/Antivenom: Shirish is an Ayurvedic anti-poisoning herb considered the most powerful antidote against a large number of animal and plant origin poisons.

3. Phytochemistry: Key Constituents and Active Compounds

3.1 Overview of Phytochemical Classes

A. lebbeck contains numerous phytochemicals related to alkaloids, anthraquinones, essential oils, flavonoids, glycosides, phenolics, phytosterol, saponins, steroids, and triterpenoids. Phytochemical studies revealed an abundance of saponins together with other chemicals including flavonoids, phenols, and glycosides.

3.2 Saponins

Triterpenoid saponins are considered the most pharmacologically important class of compounds in A. lebbeck. To date, a total of 149 saponin compounds have been isolated and identified from Albizia species. Several saponins unique to A. lebbeck have been formally characterized. Albiziasaponins A–E are oleanene triterpenes present in Albizia lebbeck. Additional saponins recorded from the species include echinocystic acid glycosides and albiziahexoside. The phytoconstituents reported in the plant include melacacidin, D-catechin, β-sitosterol, albiziahexoside, betulinic acid, and echinocystic acid glycosides, which are responsible for various potent physiological and pharmacological activities.

3.3 Flavonoids

The leaves contain kaempferol. Kaempferol, quercetin, sophoflavescenol, and kurarinone have been isolated from A. lebbeck. HPLC analysis of a seed extract indicated the presence of quercetin, gallic acid, m-coumaric acid, and sinapic acid. These flavonoids are regarded as important contributors to the antioxidant and anti-inflammatory profiles of the plant.

3.4 Alkaloids

Macrocyclic budmunchiamine alkaloids have been isolated from Albizia lebbeck. N-demethyl budmunchiamines have also been reported from Albizzia lebbeck seeds. Alkaloids including albigenin have been identified and are considered to contribute to the plant's neurological and antimicrobial activities.

3.5 Tannins and Phenolic Compounds

Stem bark yields tannins (7 to 11%); D-catechin has also been identified. Tannins and other polyphenols contribute to the astringent and wound-healing properties described in traditional systems.

3.6 Other Compounds

Many chemical constituents have been isolated from Albizia lebbeck, such as lebbekannin, echinocystic acid, flavonoids, linoleic acid, and saponins. A novel β-lactam derivative, albactam, from the flowers of Albizia lebbeck has been reported to exhibit platelets anti-aggregatory activity in vitro.

4. Mechanisms of Action

4.1 Antihistaminic and Mast Cell Stabilization

The ethanolic extract of A. lebbeck stem bark inhibited histamine signaling in sensitized rats at a dose of 200 mg/rat through suppression of H1 receptors and histidine decarboxylase gene (HDC) transcriptions. The alcoholic extract of Albizia lebbeck (L.) has been reported to possess antihistaminic property, by neutralizing histamine directly or due to a corticotrophic action.

4.2 Anti-inflammatory Pathway

The aqueous extract of the bark of Albizia lebbeck showed promising anti-inflammatory results, including reduced eosinophils, neutrophils, and TNF-α levels in various experimental studies. Alcoholic extract of the stem bark of Albizia lebbeck was found to possess strong analgesic and moderate anti-inflammatory activities, possibly due to the presence of steroids and steroidal glycosides.

4.3 Immunomodulatory Effects

The aqueous bark extract demonstrated immunomodulatory effects, including reduction of OVA-specific IgE and IL-4 levels and enhancement of IFN-γ in animal models.

4.4 Neurological Mechanisms

There is evidence that ethanolic extract of A. lebbeck increases the brain content of gamma-amino butyric acid (GABA) and serotonin, which is attributed to depressive and anti-convulsive traits. Aqueous and ethanolic extracts of the leaves exhibit significant central analgesic activity and act possibly via GABAergic and serotonergic pathways. Isolated saponins inhibited passivity and hypothermia induced by a GABA agonist, and researchers concluded that GABA was involved in the nootropic and anxiolytic effects of the compound.

Cholinergic deficits were ameliorated by A. lebbeck leaf extract co-administration, possibly by the inhibition of hyperactive acetylcholinesterase (AChE). A hexane extract of A. lebbeck leaves inhibited specific ER stress proteins, including calpain-1 and caspase-12, providing a mechanistic basis for neuroprotection.

4.5 Antioxidant Mechanisms

A 70% ethanolic extract of bark of Albizia lebbeck (L.) possesses antioxidant and hepatoprotective effects owing to its principle phenolic components. Free radical scavenging activity attributable to flavonoids such as quercetin and kaempferol has been documented in DPPH assays across multiple in vitro studies.

5. Scientific Evidence by Area of Use

5.1 Respiratory Conditions — Bronchial Asthma and Allergy

This is the area with the most clinical evidence, though all available human studies are small and methodologically limited.

Human clinical study (single-blind, uncontrolled): The present study was conducted on 81 patients at inpatient and outpatient levels. Patients were given Albizia lebbeck stem bark decoction (Shireesh Twak Kwatha) in a dose of 50 ml thrice daily for 6 weeks, supported by light diet. The results were assessed in terms of clinical recovery, symptomatic relief, and pulmonary function improvement. A significant increase in PEFR (peak expiratory flow rate) and a considerable decrease in total leukocyte count, eosinophil count, and ESR were observed. Of the 50 patients who completed the trial, 56% were reported to experience a good improvement response, 38% a fair response, and only 6% a poor response. The study concluded that Albizia lebbeck stem bark decoction can be used as an effective drug in bronchial asthma; however, detailed observational studies are required to demonstrate the effect at the molecular level.

Evidence quality: This single-blind study had significant dropout (31 of 81 patients) and lacked a placebo control or randomization. It provides preliminary but not definitive human evidence. Clinical studies have proven the effect of Albizia lebbeck and its formulation Shirishavaleh in bronchial asthma, though these are Ayurvedic clinical evaluations rather than controlled RCTs.

Animal and mechanistic data: A decoction of the flowers and bark of Albizia lebbeck was shown to protect guinea pigs against histamine and acetylcholine-induced bronchospasm in an animal study. In the same study, decoctions of the bark alone protected sensitized animals against antigen challenge alongside a significant reduction of blood cholesterol in treated animals.

An early foundational study published in PubMed (PMID: 544953) specifically investigated the mechanism of the anti-allergic effect. Studies were conducted on the decoction of the bark of Albizzia lebbeck, which has been in use by Ayurvedic physicians for bronchial asthma and eczema. The effect of A. lebbeck was studied on the degranulation rate of sensitized peritoneal mast cells of albino rats when challenged with antigen (horse serum).

Overall, the respiratory evidence base consists of one small, uncontrolled clinical trial supported by multiple animal and cell-based studies. No large randomized controlled trials exist.

5.2 Anti-allergic and Immunomodulatory Effects

Phytoconstituents found in Albizia lebbeck have properties to suppress histamine-induced allergic reactions like bronchospasm, pulmonary eosinophilia, spreading skin diseases like erysipelas, and anaphylaxis in food allergies. Allergic reactions are mediated mainly by Histamine H1 receptor (H1R) and Histidine Decarboxylase (HDC) genes. Suppression of both targets has been demonstrated at the molecular level in rodent models.

Evidence is largely preclinical. No placebo-controlled clinical trials specifically for allergic rhinitis or atopic dermatitis have been published in the peer-reviewed literature.

5.3 Neuroprotection, Nootropic, and Neurological Effects

The n-butanolic fraction of the methanolic extract of Albizia lebbeck leaves showed nootropic and anxiolytic activity at a dose of 25 mg/kg administered to albino mice. This effect was evaluated using the elevated plus maze test.

Alzheimer's disease (animal): The objective of one PMC-indexed study was to evaluate the therapeutic potential of Albizia lebbeck (L.) seeds for Alzheimer's disease. Hydromethanolic extract of Albizia lebbeck seeds was prepared by maceration and characterized by physico-chemical, phytochemical, and HPLC analysis. Thirty-six Wistar albino rats were divided into six groups, with treatment groups receiving ALE at 100, 200, and 300 mg/kg doses. ALE significantly improved memory and cognitive impairments. Endogenous antioxidant stress biomarker levels and histopathological outcomes supported the therapeutic potential. Cholinergic deficits were also ameliorated by ALE co-administration, possibly by the inhibition of hyperactive acetylcholinesterase (AChE). Docking studies supported the potential of ALE against AD. The data suggested that ALE has neuroprotective potential that can be exploited for beneficial effects in treating AD.

Parkinson's disease (animal): One PMC-indexed study aimed to validate the traditional use of Albizia lebbeck and delineate its mechanism of action in PD. A systems pharmacology approach was employed; the haloperidol-induced catalepsy model was adopted as the experimental model of PD for in-vivo studies in Wistar albino rats. In-vivo studies revealed that Albizia lebbeck improved motor functions and endurance as demonstrated in behavioral studies, further supported by the rescue of endogenous antioxidant defense and reversal of ultrastructural damage in histological studies. A systems pharmacology approach identified 25 drug-like compounds interacting with 132 targets. Kaempferol, phytosterol, and okanin were found to be important compound nodes with prominent target nodes of TDP1 and MAPT.

Neuroprotection at the cellular level: A PMC-indexed study aimed to investigate the effect and mechanism of A. lebbeck leaf extracts on glutamate-induced neurotoxicity and apoptosis linked to ER stress using human microglial HMC3 cells. Leaves were extracted using hexane, mixed solvents, and ethanol. Each extract was evaluated for cytotoxic effects on HMC3 cells, and non-cytotoxic concentrations were pretreated with the cells before glutamate challenge. Results showed the hexane extract exhibited the highest protective effect and inhibited specific ER stress proteins, calpain-1 and caspase-12.

Evidence quality: Neurological evidence is entirely preclinical (animal models, cell lines, computational docking). There is no direct scientific evidence yet from human trials that suggests the therapeutic potential of A. lebbeck seeds in Alzheimer's disease. No human clinical trials in neurodegenerative disease have been published.

5.4 Antimicrobial Activity

Petroleum ether and ethyl acetate extracts of the stem bark showed the most prominent activity in antimicrobial susceptibility tests, with moderate activity against Bacillus subtilis, Staphylococcus aureus, Vibrio mimicus, Salmonella typhi, Shigella dysenteriae, Candida arrizae, and Aspergillus niger. The zone of inhibition against tested bacteria and fungi were 11–14 mm and 8–10 mm, respectively.

Evidence is exclusively in vitro. No human clinical trials for infectious disease have been conducted.

5.5 Antimalarial Activity

One PMC-indexed study tested the antimalarial activity of ethanolic bark extract of A. lebbeck (EBEAL). EBEAL was prepared by Soxhlet extraction and evaluated for in vitro antimalarial activity against Plasmodium falciparum chloroquine-sensitive (MRC2) and chloroquine-resistant (RKL9) strains. In early infection studies, there was a dose-dependent decrease in levels of parasitaemia on day 7 compared to controls after oral administration of different concentrations of the extract. The standard drug chloroquine caused chemosuppression of 96.8%, whereas concentrations of 100, 250, 500, 750, and 1000 mg/kg/day caused chemosuppression of 69.4%, 71.4%, 71.9%, 79.8%, and 84.7%, respectively.

Evidence is in vitro and animal (murine malaria model) only. No human trials have been conducted.

5.6 Anticancer Activity

The leaves and pods of A. lebbeck were claimed to be used against cancer in traditional medicine. Previous studies using bark, leaves, seeds, and pods of A. lebbeck showed cytotoxic activity against hepatic, colon, larynx, cervical, and breast cancer cell lines. In silico testing of albiziasaponins for structure-based pharmacological activity prediction using PASS Online software and docking with Autodock revealed anticancer and apoptogenic potential. Antiproliferative activity of the saponin-rich fraction was performed using MCF-7 human breast cancer cells by MTT assay methods, and the saponin-rich fraction of A. lebbeck showed antiproliferative, antiangiogenic, and apoptogenic potential in various in vitro models.

Triterpenoid saponins from Albizia lebbeck (L.) Benth were studied for their inhibitory effect on the survival of high-grade human brain tumor cells.

Evidence quality: All anticancer evidence is confined to in vitro cell-line studies and computational docking. No animal tumor models or human trials have been published for this indication.

5.7 Antidiabetic and Metabolic Effects

The leaf extracts of A. lebbeck have been reported to possess antihyperglycaemic and antidiabetic potential. One study investigated antidiabetic, renal, hepatic, pancreatic, cardiac protective, and antioxidant potential of a methanol/dichloromethane extract of Albizzia lebbeck stem bark on streptozotocin-induced diabetic rats. Evidence is exclusively animal-model based; no human clinical data exist.

5.8 Antifertility and Reproductive Effects

Significant preclinical evidence exists for antifertility effects, which is important from a safety perspective.

Male antifertility (animal study): Methanolic extract of Albizia lebbeck bark, when administered orally at the dose level of 100 mg/rat/day to male rats of proven fertility for 60 days, did not cause any significant loss in body weight, but the weights of reproductive organs — testis, epididymides, seminal vesicle, and ventral prostate — were decreased significantly compared to controls. Sperm motility as well as sperm density were reduced significantly, resulting in a reduction of male fertility by 100%. Populations of preleptotene, pachytene, secondary spermatocytes, and step-19 spermatid declined by 60.86%, 65.81%, 71.56%, and 66.55%, respectively. Cross-sectional surface area of Sertoli cells and cell counts were also depleted significantly.

Female antifertility (animal study): Farag et al. (2013) reported that saponins of A. lebbeck seeds exhibited antiovulatory properties in female rats. The antifertility activities in female rats were very likely attributable to the toxic action of saponin and other plant steroids contained in the extract of A. lebbeck stem bark.

These are animal findings and have not been replicated in humans; nevertheless, they constitute an important preclinical safety signal.

5.9 Analgesic and Antipyretic Effects

The possible central analgesic activity and underlying mechanism of action of the aqueous and ethanolic extracts of A. lebbeck leaves were investigated in Wistar rats using Eddy's hot plate and tail flick tests. Rats pretreated with bicuculline and methysergide showed a significant reduction in analgesic activity compared to untreated extract groups. The extracts exhibited significant central analgesic activity and act possibly via the GABAergic and serotonergic pathways. The flavonoids and saponins found in the leaves are believed to be responsible for the observed analgesic effect.

5.10 Wound Healing

The plant is credited with wound healing, anti-inflammatory, and anti-helminthic properties. Topical applications of bark paste and infusion have been evaluated in rodent models, showing improved healing rates attributable to the anti-inflammatory and antimicrobial properties of the extract.

6. Body Systems Associated with Albizia lebbeck

• Respiratory system: Anti-asthmatic, antiallergic, bronchospasmolytic activity (best-evidenced area).
• Immune system: Anti-anaphylactic, mast cell stabilization, and immunomodulatory activities. It effectively functions as an immunomodulator against Plasmodium, Proteus vulgaris, and Staphylococcus aureus infections.
• Central nervous system: According to pharmacological studies, the species exhibited excellent neuroprotective activities such as anti-Parkinson's and anti-Alzheimer's activities, as well as nootropic effects.
• Endocrine / Reproductive system: Antiandrogenic and antifertility activities demonstrated in animal models (saponins and steroids implicated).
• Gastrointestinal system: Traditional use for diarrhoea and dysentery, with preclinical antidiarrhoeal evidence.
• Integumentary system (skin): Wound healing, antimicrobial, and anti-eczema uses in traditional medicine, supported by in vitro antimicrobial studies.
• Cardiovascular system: Anti-platelet aggregatory activity reported for the novel compound albactam from flowers; traditional use for venereal diseases.
• Hepatic / Metabolic system: Antioxidant and hepatoprotective effects attributed to phenolic components.

7. Dosage Forms and Doses Reported in Studies

All dosages below are as explicitly stated in the cited sources and relate to either traditional Ayurvedic practice or reported study parameters. They do not constitute dosing recommendations.

• Stem bark decoction (clinical study, bronchial asthma): A single-blind study on 81 patients with bronchial asthma used a traditionally prepared stem bark decoction at a dose of 50 mL three times daily, administered over a 6-week treatment phase.
• Powder (traditional Ayurvedic dose): Bark powder: 3–6 grams per day; water decoction: 50–100 mL; fresh juice: 10–20 mL.
• Powder and juice (Ayurvedic IAFA reference): Powder (Choornam): 3–5 g per day; Juice (Swarasam): 20–30 mL twice a day; Decoction (Kwatham): 60–100 mL per day.
• Ethanolic extract (anti-histaminic rodent study): The ethanolic extract of A. lebbeck stem bark inhibited histamine signaling in sensitized rats at a dose of 200 mg/rat.
• n-Butanolic fraction (nootropic rodent study): The n-butanolic fraction of the methanolic extract of A. lebbeck leaves showed nootropic and anxiolytic activity at a dose of 25 mg/kg administered to albino mice.
• Ethanolic extract (antifertility study): Methanolic extract of Albizia lebbeck bark was administered orally at 100 mg/rat/day to male rats for 60 days.
• Ethanolic bark extract (antimalarial rodent study): Concentrations of 100, 250, 500, 750, and 1000 mg/kg/day were evaluated for chemosuppression of P. berghei in an in vivo murine model.
• Hydromethanolic seed extract (Alzheimer's rodent study): Treatment groups in the AD animal study received ALE at 100, 200, and 300 mg/kg dose levels.
• Methanolic leaf extract (acute toxicity study): The methanolic extract of Albizia lebbeck had a good margin of safety and did not show any lethal effects in animals up to doses of 2000 mg/kg; hence the LD50 was considered as 2000 mg/kg. Studies were carried out with 1/10 of the LD50 as the effective dose of 200 mg/kg and double the effective dose at 400 mg/kg.

8. Safety Considerations

8.1 Acute Toxicity Data

The median lethal dose (LD50) for ethanolic bark extract of A. lebbeck was determined to be greater than 5 g/kg in BALB/c mice. No mortality was observed with this concentration during the study period. These observations revealed the safety of A. lebbeck as a medicinal plant without severe acute side effects.

Oral administration of methanol extract of A. lebbeck leaves at doses of 2000 mg/kg and 5000 mg/kg did not cause any mortality or sign of acute toxicity in the study animals. The acute toxicity study of the 70% methanol extract of A. lebbeck leaves therefore demonstrated an oral LD50 greater than 5000 mg/kg.

8.2 Sub-acute Toxicity Concerns

The sub-acute toxicity study of the 70% methanol extract of A. lebbeck leaves did not adversely affect body weight or the histological structure of the stomach of treated rats at doses of 100 mg/kg and 400 mg/kg. However, the plant extract at these doses caused a significant decrease in some hematological parameters and histopathological lesions in the liver.

Due to its use in traditional medication and the consideration of its leaves and pods as potential fodder for livestock, the toxicity of Albizia lebbeck needs to be thoroughly explored.

8.3 Reproductive and Antifertility Signals

This is the most important specific safety signal identified in preclinical research. In male rats administered 100 mg/rat/day of methanolic extract of Albizia lebbeck bark for 60 days, the weights of reproductive organs (testis, epididymides, seminal vesicle, and ventral prostate) were decreased significantly, and sperm motility as well as sperm density were reduced significantly, resulting in a reduction of male fertility by 100%. Plant estrogens work by binding to the same intracellular estrogenic receptors, thereby triggering multiple estrogenic activities such as uterotropic effect, sterility, or disruption of normal reproductive processes. The antifertility activities revealed in female rats were very likely attributable to the toxic action of saponin and other plant steroids contained in the extract of A. lebbeck stem bark.

These findings are from animal models and have not been confirmed in humans; however, they constitute a documented preclinical concern of relevance to individuals of reproductive age.

8.4 Allergic Reactions

Albizia lebbeck bark is generally considered safe for wound healing, but some people may experience allergic reactions such as itching or rash, especially in those with sensitive skin.

8.5 Gaps in Safety Data

Studies are required to estimate the potential side effects at therapeutic doses in humans. In support of its therapeutic uses, more extensive scientific clinical trials are necessary. No systematic human safety studies, pharmacokinetic studies, or drug interaction studies have been published in the peer-reviewed literature. No regulatory body (NIH, EMA, WHO) has issued a formal safety monograph or approved indication for Albizia lebbeck as a dietary supplement.

9. Overall Evidence Assessment

Systematic investigation has revealed that A. lebbeck consists of various phytochemicals, including major alkaloids, flavonoids, saponins, and terpenoids. Its crude extract, fraction, and bioactive compounds have exhibited adulticidal, antiallergic, anticancer, anticonvulsant, antidiabetic, antidiarrheal, anti-inflammatory, antimicrobial, antinociceptive, antioxidant, antiparasitic, antipyretic, antivenom, estrogenic, neuroprotective, nootropic, ovicidal, and wound healing activities in experimental settings.

Nonetheless, the overall clinical evidence base is weak. A. lebbeck has been studied for many pharmacological activities against allergy, cancer, convulsant, diabetes, inflammation, parasitic infestation, snake venom, nootropic, pyrexia, and diarrhea, yet there remains still a scarcity of information on the mechanism of action. Studies are required to estimate the potential side effects. Moreover, mechanistic physiognomies of the isolated compounds with known bioactivities are quite limited; thus, forthcoming research needs to focus on the mechanisms of these active phytochemicals to facilitate their potential enrollment for drug discovery.

The anti-asthmatic and antiallergic area is the most clinically investigated, backed by one small single-blind human study and multiple animal and mechanistic studies. All other indications — including anticancer, antidiabetic, neuroprotective, antimalarial, and nootropic — are supported only by preclinical (in vitro or animal model) data.

References

• Balkrishna A. et al. (2022). A Comprehensive Insight into the Phytochemical, Pharmacological Potential, and Traditional Medicinal Uses of Albizia lebbeck (L.) Benth. Evidence-Based Complementary and Alternative Medicine. PMC9050289.
• Kumar V. et al. (2010). The Clinical Effect of Albizia lebbeck Stem Bark Decoction on Bronchial Asthma. International Journal of Pharmaceutical Sciences and Drug Research.
• Studies on the mechanism of action of Albizzia lebbeck, an Indian indigenous drug used in the treatment of atopic allergy. PubMed PMID: 544953.
• Antimalarial efficacy of Albizia lebbeck (Leguminosae) against Plasmodium falciparum in vitro & P. berghei in vivo. PMC4795339.
• Saleem U. et al. (2019). Experimental and Computational Studies to Characterize and Evaluate the Therapeutic Effect of Albizia lebbeck (L.) Seeds in Alzheimer's Disease. Medicina. PMC6572470.
• Saleem U. et al. (2019). Systems pharmacology based approach to investigate the in-vivo therapeutic efficacy of Albizia lebbeck (L.) in experimental model of Parkinson's disease. PMC6896792.
• Neuroprotective Effects of Albizia lebbeck (L.) Benth. Leaf Extract against Glutamate-Induced Endoplasmic Reticulum Stress and Apoptosis in Human Microglial Cells. PMC10384906.
• Gupta RS, Kachhawa JB, Chaudhary R. (2006). Antispermatogenic, antiandrogenic activities of Albizia lebbeck (L.) Benth bark extract in male albino rats. Phytomedicine 13:277–283.
• Desai TH and Joshi SV. (2019). Anticancer activity of saponin isolated from Albizia lebbeck using various in vitro models. Journal of Ethnopharmacology.
• A comparative study of in vitro antimicrobial, antioxidant and cytotoxic activity of Albizia lebbeck and Acacia nilotica stem bark. Egyptian Journal of Basic and Applied Sciences. 2017.
• Biosynthesis of zinc oxide nanoparticles using Albizia lebbeck stem bark, and evaluation of its antimicrobial, antioxidant, and cytotoxic activities on human breast cancer cell lines. PMC6304255.
• Antimicrobial and Cytotoxic Activities of Constituents from the Fruit of Albizia lebbeck L. Benth (Fabaceae). PMC9369593.
• A Review on Parts of Albizia lebbeck (L.) Benth. Used as Ayurvedic Drugs. Research Journal of Pharmacy and Technology. 2013.
• Saponins from Genus Albizia: Phytochemical and Biological Review. Longdom Open Access.
• Herb of the Month — Albizia lebbeck. Naturopaths & Herbalists Association of Australia (NHAA).
• Effects of Methanol Extract of Albizia lebbeck Leaves on Body Weight, Hematological Parameters and Histological Structures of Digestive Organs in Rats. Journal of Biology and Life Science.
• Diuretic Activity of Methanolic Extract of Albizia lebbeck. RROIJ Open Access Journals.
• Saleem U. et al. (2019). Experimental and Computational Studies to Characterize and Evaluate the Therapeutic Effect of Albizia lebbeck (L.) Seeds in Alzheimer's Disease. Medicina 55(5):184. MDPI.
• Antifertility effects of crude extracts from Acacia nilotica pods and Albizia lebbeck stem bark in female multimammate rats. Journal of Physiology and Pathophysiology. Academic Journals.
• Samant S. (2023). Phytochemistry and Therapeutic Uses of Albizia lebbeck. Sybes Pharmacy Publication.