🌿 This month’s Herb of the Month is Albizia lebbeck
Family: Fabaceae/Leguminosae
🌿 Description:
Native to India, Bangladesh, Pakistan, Thailand, Malaysia, Southern China and Northern Australia, the deciduous Albizia tree is a spectacular specimen, growing up to 30 metres in both height and canopy width. Widely cultivated around the world, it has a great many low-growing, multi-stemmed branches, making them valued for shade in recreational areas and as a renewable source of high quality, strong, hardwood. The outer bark of the Albizia tree has a rough and flakey texture and grey- violet shade, with pale green to grey leaves between 7-15cm long. Albizia trees have heavily fragranced, nectar-rich white flowers that appear shortly after new leaves in the growing cycle and are extremely attractive to bees, butterflies and birds. Striking, leathery, paper-like seed pods create a distinctive rattling sound when agitated by the wind, no doubt inspiring one of its colloquial names – the ‘Shak-Shak tree’. (1)
🌿 History and traditional use:
It is thought that the Albizia species was named after the 18th century nobleman, Filipo del Albizi, who was the first person to cultivate the trees on a large scale. (1)
The bark of the tree is a common prescription in the Ayurvedic system of herbal medicine, most commonly applied internally for respiratory disorders, bronchitis, allergies and eczema and other pruritic skin disorders. There are also records of application in many inflammatory and gastrointestinal disorders, oral and optical infections and diseases, urinary, genital and anorectal presentations and neurological disorders (2, 3). The leaves have a long-standing reputation for improving night blindness, perhaps due to their density of nutrients, and combinations of plant parts have also been used in topical applications for snake bites, scorpion stings and ulcers (4).
🌿 Actions and indications:
Despite its strong traditional reputation and prolific medicinal use around the world, Albizia has not yet been significantly investigated in human clinical trials. However, the combination of in -vitro, in-vivo and traditional evidence we have at hand, in addition to modern clinical anecdotal data, creates a set of theoretical yet clinically useful actions including:
- Alterative (4)
- Antiallergic (5)
- Antiarthritic (1)
- Antibacterial (1)
- Antiinflammatory (1)
- Antimicrobial (1)
- Antiprotozoal (1, 4)
- Antitumour (4)
- Astringent (1)
- Hypocholesterolaemic (5)
- Hypoglycaemic (4)
- Insecticidal (4)
- Memory enhancer (1) and nootropic (6)
These actions translate into a clear set of indications for Albizia used in modern herbal medicine:
- Allergies (allergic rhinitis, urticaria) (1, 5)
- Asthma and other allergic respiratory diseases (1, 2)
- Diarrhoea and dysentery (1)
- Bronchitis (2)
- Inflammatory disorders (2)
- Eczema (5)
- Hypercholesterolaemia (5)
🌿 Science and clinical trials:
Albiziasaponins A, B and C appear to be the most significantly active constituents in Albizia (2). They have demonstrated anti-asthmatic activity via inhibiting mast cell granulation and reducing cell-mediated immunity in rats. These albiziasaponins also have a disodium chromoglycate like action on mast cells, causing a very specific action in reducing bronchial spasms. The bark and stem bark contain a variety of tannins and pseudotannins, including lebbecacidin, that exert expectorant activity in animal studies (2,3).
Several animal models suggest that constituents in Albizia can inhibit cyclooxygenase activity and prostaglandin synthesis. Albizia has increased superoxide dismutase and catalase and decreased lipid oxidation in arthritic rats in-vivo (1).
Albizia preparations have demonstrated activity in-vitro against Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella type and Staphylococcus aureus, Vibrio cholera and Aeromonas hydrophila and methanolic extracts of have demonstrated antitrypanosomal activity against Trypanosoma cruzi (1), suggestive of a potentially broad antimicrobial activity warranting further investigation.
Whilst Albizia has not been significantly investigated via human clinical trials, substantial preclinical evidence supports its traditional Ayurvedic uses in the following conditions:
Allergies and Asthma:
A single-blind study on 81 patients with bronchial asthma assessed improvements in clinical recovery, symptomatic relief and pulmonary function over a 6 week treatment phase. A traditionally prepared stem bark decoction at a dose of 50mL three times daily was administered. 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. This led to the researcher’s conclusion that Albizia lebbeck treatment, as a traditional decoction, was an effective treatment for bronchial asthma (2).
A decoction of the flowers and bark of Albizia lebbeck were shown to protect guinea pigs against histamine and acetylcholine induced bronchospasm in an animal study designed to investigate its potential anti-asthmaatic and anti-allergic actions. In the same study, decoctions of the bark alone protected sensitized animals against the antigen challenge alongside a significant reduction of blood cholesterol in treated animals (7).
Nootropic activity and memory enhancement:
Isolated saponins from Albizia lebbeck given to both healthy and amnesic rats were shown to result in significant improvements in memory retention and anxiety. Measured via performance in maze tests, the saponins also inhibited passivity and hypothermia induced by a GABA agonist. The researchers concluded that GABA was involved in the nootropic and anxiolytic effects of the compound (6).
Other animal models have demonstrated that Albizia also influences serotonin and dopamine production (8,9). Saponins extracted from dried leaves decreased GABA and dopamine concentrations in the brain while increasing serotonin levels in one study (8) and ethanolic extracts of the leaves raised brain concentrations of both GABA and serotonin in addition to demonstrating anticonvulsant activity in another (9).
Neuroprotective activity (potential):
Extractions of Albizia lebbeck have been shown to inhibit glutamate-induced neurotoxicity via endoplasmic reticulum stress and apoptosis signalling pathways. It appears to activate cellular antioxidant enzymes in HMC3 cells, which is likely a neuroprotective action, suggesting that Albizia may offer a preventative strategy for neurodegenerative diseases.
🌿 Prescribing considerations:
Australian manufacturer dose recommendations for 1:2 liquid extract are 3.5-8.5mL daily/25-60mL weekly (5) or equivalent to 3-6g dried herb powder daily (2). The toxicity of Albizia is unknown but in the absence of robust evidence, it is theoretically possible that Albizia may:
- Potentiate pentobarbitone-induced sleep as observed in-vivo, and should thus be prescribed with caution in patients taking barbiturate medications
- Increase the risk of serotonin syndrome and should thus be prescribed with caution for people taking tricyclic and selective serotonin reuptake inhibitor drugs
- Reduce male fertility markers as observed in-vivo and should thus be prescribed with caution for males with poor sperm motility and/or low sperm counts who wish to conceive children
- Have additive effects in those taking antihistamine and mast-cell stabilising drugs due to observations in-vivo.
There is no reliable data on the safety of Albizia in pregnancy and lactation, so it is best avoided by these patient cohorts (1).
🌿 References:
- Braun L and Cohen M 2015, Herbs and Natural Supplements 4th Edition, Volume 2, Churchill Livingstone, Elsevier, Australia.
- Kumar S, Bansal P, Gupta V, Sannd R and Rao MM 2010, The Clinical Effect of Albizia lebbeck Stem Bark Decoction on Bronchial Asthma, National Institute of Ayurvedic Pharmaceutical Research, Patiala, Punjab, India, International Journal of Pharmaceutical Sciences and Drug Research, 2(1): 48-50
- Balkrishna A, Sakshi, Chauhan M, Dabas A, Arya V 2022. A Comprehensive Insight into the Phytochemical, Pharmacological Potential, and Traditional Medicinal Uses of Albizia lebbeck (L.) Benth. Evid Based Complement Alternat Med. 2022 Apr 21;2022.
- Kapoor LD 2001, Handbook of Ayurvedic Medicinal Plants, CRC Press.
- Bone K 2003, A Clinical Guide to Blending Liquid Herbs, Churchill Livingstone, Elsevier, Australia.
- Une HD, Sarveiya VP, Pal SC, Kasture VS and Kasture SB 2001, Nootropic and anxiolytic activity of saponins of Albizzia lebbeck leaves, Pharmacology Biochemistry and Behaviour, 69:3-4, pp. 439-444
- Tripathi RM and Das PK 1977, Studies on anti-asthmatic and anti-anaphylactic activity of Albizia lebbeck, Indian Journal of Pharmacology, 9:3, pp. 189-194
- Chintawar SD, Somani RS, Veena S, Kasture 2002, Nootropic activity of Albizia lebbeck in mice, Journal of Ethnopharmacology, 81:3, pp. 299-305
- Kasturi VS, Chopde CT and Deshmukh VK 2000, Anticonvulsive activity of Albizzia lebbeck, Hibiscus rosa sinesis and Butea monosperma in experimental animals, Journal of Ethnopharmacology, 71:1-2, pp. 65-75
- Phoraksa O, Chimkerd C, Thiyajai P, Judprasong K, Tuntipopipat S, Tencomnao T, Charoenkiatkul S, Muangnoi C, Sukprasansap M 2023. Neuroprotective Effects of Albizia lebbeck (L.) Benth. Leaf Extract against Glutamate-Induced Endoplasmic Reticulum Stress and Apoptosis in Human Microglial Cells. Pharmaceuticals, 16(7):989.