Lannea coromandelica (Anacardiaceae) Indian Ash Tree, Jhingan, Wodier

Aug 12

23 min read

Lannea coromandelica, known as Jhingan or Indian Ash Tree, is a medium-sized deciduous tree that announces the arrival of spring across the Indian subcontinent not with flowers, for its blooms are small and inconspicuous, but with a flush of copper-red, densely pubescent new foliage that gradually matures to a rich green, transforming the leafless winter canopy in a matter of weeks. It belongs to the Anacardiaceae, the cashew family, a lineage that includes the mango, the pistachio, and the irritant poison ivy, and its bark yields a copious, reddish, gummy exudate that has been employed for centuries in Ayurveda and folk medicine as a wound dressing, an anti-inflammatory agent, and a treatment for oral and gastrointestinal ulcers. The tree is a familiar presence in the dry deciduous forests and agricultural landscapes of the region, valued for its timber, its tannin-rich bark used in leather processing, and its medicinal gum. Modern pharmacological investigation, intensifying through 2025, has validated several of these traditional applications, revealing significant wound-healing, anti-inflammatory, antimicrobial, and antioxidant activities driven by a rich endowment of flavonoids, tannins, and triterpenoids. Lannea coromandelica is a tree of quiet, persistent utility, its medicinal identity slowly emerging from the shadow of its more celebrated family members.

1. Taxonomic Insights

Species: Lannea coromandelica (Houtt.) Merr.

Family: Anacardiaceae (Cashew Family)

Genus: Lannea

Synonyms: Odina wodier Roxb., Lannea grandis (Dennst.) Engl., Lannea wodier (Roxb.) Adelb., Dialium coromandelicum Houtt.

The taxonomic history is convoluted. The species was described by Houttuyn in 1774 as Dialium coromandelicum, transferred to Lannea by Merrill in 1938, and simultaneously known for two centuries under the name Odina wodier, published by Roxburgh in 1832. The synonym Lannea grandis also persists in some older literature. The currently accepted name is Lannea coromandelica, though Lannea wodier remains widely encountered in the Indian ethnopharmacological literature. The genus Lannea was established by Achille Richard in 1832 and comprises approximately 40 species of trees and shrubs distributed across tropical Africa and Asia. The specific epithet coromandelica refers to the Coromandel Coast of southeastern India, where the type specimen was collected.

Botanical Description

Lannea coromandelica is a medium-sized, deciduous tree, reaching 10 to 20 metres in height, with a short, stout, often crooked trunk and a spreading, umbrella-shaped crown. The tree is entirely bare during the winter months, its thick, rough bark and gnarled branching architecture lending it a stark, sculptural presence in the dry landscape.

Key Identification Features:

The bark is thick, rough, and deeply fissured, greyish-brown to dark brown on the outside, exuding a reddish, gummy, astringent sap when cut. This gum hardens on exposure to air. The branches are stout, with prominent leaf scars, and the young shoots are covered in a dense, soft, rusty-brown pubescence. The leaves are alternate, imparipinnate, and clustered at the branch tips, 20 to 40 centimetres in length. They consist of 5 to 11 opposite or sub-opposite leaflets. Each leaflet is ovate-oblong to elliptic, 5 to 15 centimetres long and 3 to 7 centimetres wide, with an acuminate apex and an oblique, rounded base. The margin is entire. Young leaflets are a striking copper-red and densely pubescent on both surfaces. Mature leaflets are dark green and glabrous above, paler and glabrous to sparsely pubescent beneath. The petiole and rachis are pubescent. The tree is leafless from approximately December to February, with the new foliage emerging in March and April.

The inflorescence is a terminal or axillary, compound raceme, 10 to 25 centimetres long, appearing shortly before or with the new leaves. The tree is dioecious, bearing male and female flowers on separate trees. The flowers are small, greenish-yellow to purplish, and inconspicuous, each approximately 4 to 5 millimetres across. The calyx is 4-lobed, and the corolla consists of 4 oblong petals. Male flowers have 8 stamens. Female flowers have a superior, 4-locular ovary with 4 styles. The fruit is a drupe, ovoid to reniform, 1 to 1.5 centimetres long, smooth, and reddish-purple to black when ripe. The mesocarp is thin and acidic. The fruit contains a single, hard, bony stone.

Distribution: The species is native to the Indian subcontinent (India, Pakistan, Nepal, Bhutan, Bangladesh, Sri Lanka), Myanmar, Thailand, Laos, Cambodia, Vietnam, southern China (Yunnan), and the Andaman Islands. It is widely distributed across the drier regions of India, particularly in the Deccan Plateau, the Gangetic Plain, and the foothills of the Himalayas. It grows from sea level to approximately 1500 metres elevation, in dry deciduous forests, scrublands, and open woodlands. It is a characteristic component of the Anogeissus, Boswellia, Lannea association of the Indian dry deciduous forest.

Conservation Status: The species has not been formally assessed for the IUCN Red List. It is common and widespread across its range and is not considered threatened, though regional populations may be impacted by deforestation and over-exploitation for timber and gum.

Etymology

The generic name Lannea is of uncertain origin, possibly an anagram of Anela, an unpublished name, or derived from a local vernacular name. The specific epithet coromandelica refers to the Coromandel Coast of India. The Hindi name "Jhingan" and the Marathi "Shimti" are onomatopoeic or of undetermined derivation. "Wodier" is derived from the synonym Odina wodier.

2. Common Names

3. Related Herbs from the Anacardiaceae Family

Lannea coromandelica belongs to the Anacardiaceae, a family of approximately 800 species of trees, shrubs, and lianas distributed throughout the tropics and subtropics. The family is economically and medically significant, producing edible fruits and nuts (mango, pistachio, cashew), lacquer, tannins, and potent allergens and irritants (urushiol).

Mangifera indica (Mango): The most economically important member of the family. The bark, leaves, and fruit are used in Ayurveda for their astringent, anti-inflammatory, and antimicrobial properties. The polyphenolic profile of mango bark provides a comparative reference for the tannin-rich bark of Lannea.

Anacardium occidentale (Cashew): The nut is a major global commodity. The shell oil contains anacardic acids, phenolic lipids with potent antimicrobial and antitumor activities. The genus Lannea shares with Anacardium the production of phenolic lipids and alkylresorcinols.

Pistacia lentiscus (Mastic Tree): The source of mastic gum, a resin used since antiquity for its antimicrobial, anti-inflammatory, and gastroprotective properties. The gum of Lannea coromandelica is pharmacologically and functionally analogous to mastic.

Semecarpus anacardium (Marking Nut, Bhallataka): A potent Ayurvedic drug used, after detoxification, for its immunomodulatory, anticancer, and nervine properties. Its alkylresorcinols and phenolic lipids are structurally related to the compounds found in Lannea bark and gum.

Rhus coriaria (Sicilian Sumac): The dried, powdered fruits are used as a culinary spice and a traditional medicine for their astringent, antimicrobial, and antioxidant properties, driven by tannins and flavonoids. It provides a comparative phytochemical framework for the tannin-rich Lanneaceae.

The Anacardiaceae is chemically characterised by the production of phenolic lipids (alkylresorcinols, anacardic acids, urushiols), tannins (gallotannins and ellagitannins), flavonoids, and triterpenoids. The gum and bark exudates of many species are rich in tannins and have been used historically for their astringent, wound-healing, and leather-tanning properties.

4. Medicinal Uses: Summary of Primary and Secondary Actions

Primary Actions:

Wound Healing: This is the flagship traditional use of L. coromandelica and the most extensively validated pharmacological activity. The gum and bark extracts have demonstrated significant wound-healing activity in excision, incision, and dead space wound models in rats, with accelerated wound contraction, increased tensile strength, elevated hydroxyproline content, and improved histopathological architecture. The activity is attributed to the combined astringent, antimicrobial, and antioxidant effects of tannins and flavonoids.

Anti-inflammatory: Bark and gum extracts demonstrate significant, dose-dependent inhibition of carrageenan-induced paw edema, cotton pellet granuloma, and formalin-induced arthritis in rodent models. The mechanism involves inhibition of COX-2 and 5-LOX, and suppression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) via NF-κB pathway modulation.

Antimicrobial: Extracts show broad-spectrum antibacterial activity against both Gram-positive and Gram-negative organisms, including Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. Antifungal activity against Candida albicans and dermatophytes is also documented. The tannin fraction is primarily responsible.

Antioxidant: The plant exhibits potent free radical scavenging activity in DPPH, ABTS, FRAP, and superoxide radical assays. The activity correlates with total phenolic and tannin content. IC50 values in the range of 20 to 40 μg/mL for DPPH scavenging have been reported for methanolic bark extract, reflecting high phenolic content.

Gastroprotective and Antiulcer: Bark and gum extracts have demonstrated significant gastroprotective activity against ethanol-induced, aspirin-induced, and pylorus ligation-induced gastric ulcers in rats. The mechanism involves both acid-neutralising and mucosal protective factors, including enhanced mucus secretion and prostaglandin synthesis.

Secondary Actions:

Analgesic: Animal studies using acetic acid-induced writhing and hot plate models have demonstrated dose-dependent analgesic activity of bark extracts.

Antidiarrheal: The astringent tannins reduce intestinal secretion and motility, providing a mechanistic basis for the traditional use in diarrhoea and dysentery.

Hepatoprotective: Bark extracts have shown protective effects against carbon tetrachloride and paracetamol-induced hepatotoxicity in rats, with reductions in serum transaminases.

Antidiabetic: Preliminary studies report hypoglycemic activity of bark and leaf extracts in alloxan-induced diabetic rats, with α-amylase and α-glucosidase inhibition demonstrated in vitro.

Anthelmintic: Bark extracts show dose-dependent paralytic and lethal activity against Pheretima posthuma in vitro.

Anticancer: Preliminary in vitro studies have shown cytotoxic activity of bark extracts against human cancer cell lines, including breast (MCF-7) and colon (HCT-116) cells.

Medicinal Parts

Bark: The most frequently used medicinal part. A decoction is taken orally for diarrhoea, dysentery, and as a gargle for sore throat and mouth ulcers. The bark powder is dusted on wounds. The bark is rich in tannins and flavonoids.

Gum (Bark Exudate): The reddish, astringent gum that exudes from cuts in the bark is a primary wound dressing. It is applied directly to cuts, abrasions, ulcers, and chapped skin. The gum forms a protective, antimicrobial film over the wound surface.

Leaves: Used as a poultice for swellings, sprains, and boils. A decoction of the leaves is used as a mouthwash for toothache and gum inflammation. Young leaves are consumed as a vegetable in some regions.

Fruits: The ripe fruits are edible and are consumed raw. They are acidic and astringent, and are used in traditional preparations for digestive complaints.

5. Phytochemistry

The phytochemistry of Lannea coromandelica is dominated by tannins, flavonoids, and triterpenoids. The gum is primarily a complex polysaccharide-tannin matrix.

5.1 Tannins

Tannins are the most abundant and pharmacologically significant constituents of the bark and gum, accounting for their astringency, antimicrobial activity, and wound-healing properties.

Gallotannins and ellagitannins: Hydrolysable tannins that release gallic acid and ellagic acid upon hydrolysis. They are potent antioxidants and antimicrobial agents, acting by precipitating microbial proteins and inhibiting extracellular enzymes.

Proanthocyanidins (condensed tannins): Polymers of flavan-3-ols (catechin, epicatechin) that contribute to the astringency and antioxidant activity. They are present in both bark and leaves.

The total tannin content of the bark can exceed 20% of the dry weight, making it one of the more tannin-rich medicinal plants in the Indian pharmacopoeia.

5.2 Flavonoids

Quercetin, kaempferol, myricetin, and their glycosides (rutin, quercitrin): Ubiquitous flavonols with antioxidant, anti-inflammatory, and antimicrobial activities. They contribute to the wound-healing and gastroprotective effects.

Catechin, epicatechin, and epigallocatechin: Flavan-3-ols that are both monomeric antioxidants and the building blocks of proanthocyanidins.

Dihydroflavonols and flavanones: Including taxifolin and naringenin, also identified in the bark.

5.3 Triterpenoids

Lupeol and betulin: Pentacyclic triterpenoids with anti-inflammatory, anticancer, and wound-healing properties. Lupeol is a potent inhibitor of NF-κB and COX-2.

α-Amyrin, β-amyrin, and their acetates: Triterpenoid alcohols contributing to the anti-inflammatory and analgesic profile.

Oleanolic acid and ursolic acid: Triterpenoid acids with hepatoprotective and anti-inflammatory activities.

5.4 Phenolic Lipids and Alkylresorcinols

The Anacardiaceae is characterised by the production of phenolic lipids. While the urushiols of Toxicodendron and the anacardic acids of Anacardium are well-known, the phenolic lipid profile of Lannea species is less thoroughly characterised. Alkylresorcinols and related compounds have been reported from the bark and are believed to contribute to the antimicrobial activity.

5.5 Gum Composition

The gum is a complex, water-soluble polysaccharide composed of arabinose, galactose, rhamnose, and uronic acids, complexed with tannins. This tannin-polysaccharide matrix is responsible for the gum's film-forming, astringent, and antimicrobial properties, which make it such an effective traditional wound dressing.

5.6 Other Compounds

β-Sitosterol and stigmasterol are the major phytosterols. Ascorbic acid (vitamin C) is present in the leaves and fruits. The seeds contain a fixed oil, the composition of which has been partially characterised and includes oleic acid, linoleic acid, and palmitic acid.

6. Mechanisms of Action

6.1 Wound Healing Mechanism

The wound-healing activity of L. coromandelica is a multi-factorial process, not a single-receptor pharmacological event. The tannins, applied directly to the wound surface as a gum or powder, precipitate proteins in the wound exudate, forming a protective, semi-permeable pellicle that covers the wound bed. This film serves multiple functions simultaneously. First, it is a physical barrier against bacterial ingress. Second, the tannins within it exert a direct antimicrobial action by binding to and inactivating bacterial surface proteins, adhesins, and enzymes, reducing the microbial burden in the wound. Third, the astringent action reduces exudation and minor bleeding, maintaining a drier wound environment that is less conducive to bacterial proliferation. Fourth, the antioxidant flavonoids and proanthocyanidins scavenge the reactive oxygen species generated by the inflammatory response, preventing oxidative damage to the newly forming granulation tissue. Fifth, the triterpenoids, particularly lupeol, actively stimulate the proliferative phase of healing by promoting fibroblast proliferation, collagen synthesis, and angiogenesis. The combination of these five mechanisms, physical protection, chemical antisepsis, exudate control, oxidative damage limitation, and proliferative stimulation, produces the accelerated wound closure and improved scar quality observed in animal models.

6.2 Anti-inflammatory Mechanism

The anti-inflammatory activity is mediated by the triterpenoid and flavonoid fractions. Lupeol, α-amyrin, and β-amyrin inhibit the activation of NF-κB, preventing the transcription of COX-2, iNOS, and pro-inflammatory cytokines. Quercetin and myricetin contribute a direct COX-2 and 5-LOX inhibitory component, providing dual inhibition of the arachidonic acid cascade. The tannins, by precipitating proteins, may also non-specifically inhibit extracellular inflammatory mediators. The net effect is a suppression of both the cellular and enzymatic components of the inflammatory response.

6.3 Gastroprotective Mechanism

The gastroprotective effect mirrors the wound-healing mechanism, translated to the gastric mucosa. The tannins precipitate a protective proteinaceous layer on the surface of the gastric epithelium, shielding it from the corrosive effects of gastric acid and ethanol. The flavonoids and triterpenoids stimulate the synthesis and secretion of cytoprotective prostaglandins (PGE2), which increase mucosal blood flow, mucus secretion, and bicarbonate production. The combined antisecretory (acid-reducing) and cytoprotective actions account for the efficacy of the extract in multiple experimental ulcer models.

6.4 Antimicrobial Mechanism

Tannins exert their antimicrobial effect primarily through protein precipitation. They bind to and cross-link bacterial surface proteins, adhesins required for attachment to host tissues, and extracellular enzymes (proteases, hemolysins) that are virulence factors. This disrupts bacterial adhesion, colonisation, and tissue invasion. The bacterial cell wall and membrane are also compromised by tannin binding, leading to increased permeability and leakage. The flavonoids and triterpenoids contribute a membrane-destabilising effect. This multi-target, protein-precipitating mechanism is broad-spectrum and is considered less susceptible to the development of bacterial resistance than single-target, enzyme-inhibiting antibiotics.

7. Traditional and Ethnobotanical Uses

7.1 Wound Dressing and Ulcer Management

Formulation: Gum or bark powder applied directly to the wound.

Preparation and Use: This is the preeminent traditional use of L. coromandelica across the Indian subcontinent. The reddish gum that exudes naturally from cracks in the bark, or from deliberate incisions, is collected, dried, and ground into a powder. This powder is dusted directly onto cuts, abrasions, ulcers, and chronic, non-healing wounds. Alternatively, a paste is made by mixing the gum powder with a small amount of water. The bark, dried and powdered, is similarly used. The application forms a protective, astringent film that seals the wound from contamination. The dressing is typically left in place and changed once daily. In tribal communities of Madhya Pradesh, Chhattisgarh, and Odisha, the gum is a primary first-aid material.

Scientific Validation: The wound-healing activity, demonstrated in multiple animal wound models with accelerated wound contraction, increased tensile strength, and improved histopathological parameters, provides strong preclinical support. The antimicrobial and anti-inflammatory activities provide mechanistic reinforcement. This is the most robustly validated traditional use. Human clinical trials are absent.

7.2 Oral and Gastrointestinal Ulcers

Formulation: Bark decoction as a gargle or oral rinse, or taken internally.

Preparation and Use: A decoction of the bark is used as a gargle and mouthwash for aphthous ulcers (canker sores), sore throat, gingivitis, and toothache. Internally, the decoction is taken for gastric and duodenal ulcers, diarrhoea, and dysentery. The astringent tannins soothe inflamed mucosa and reduce fluid secretion. A small piece of the gum is sometimes chewed for mouth ulcers.

Scientific Validation: The antiulcer activity, demonstrated in multiple animal models of gastric ulceration, with both acid-suppressive and cytoprotective components, provides strong preclinical support. The antimicrobial activity against oral pathogens supports the traditional use in oral health. The antidiarrheal activity of tannins is a well-established pharmacological principle.

7.3 Inflammatory and Rheumatic Conditions

Formulation: Bark paste or gum paste.

Preparation and Use: The gum or bark powder is mixed with water to form a thick paste, which is applied topically to inflamed joints, sprains, and localised swellings. The paste is covered with a cloth and left in place for several hours. In some regions, a decoction of the bark is taken internally for rheumatic pain.

Scientific Validation: The anti-inflammatory activity, demonstrated in animal models of acute and chronic inflammation, with NF-κB and COX-2 inhibition, provides mechanistic support. The analgesic activity provides additional support for the pain-relieving effect.

7.4 Skin Diseases

Formulation: Gum paste or bark decoction.

Preparation and Use: The gum paste is applied to eczema, ringworm, scabies, and other skin infections. The bark decoction is used as a wash for skin eruptions and itching. The astringent and antimicrobial properties are the basis of its dermatological use.

Scientific Validation: The antimicrobial activity against S. aureus, C. albicans, and dermatophytes supports the traditional dermatological applications. The anti-inflammatory activity reduces the erythema and pruritus associated with inflammatory skin conditions.

7.5 Dysentery and Diarrhoea

Formulation: Bark decoction or gum powder.

Preparation and Use: The bark decoction, or a small amount of the gum powder mixed with water, is taken orally for acute diarrhoea and dysentery. The tannins precipitate proteins in the intestinal mucosa, forming a protective layer and reducing fluid secretion. The antimicrobial activity against enteric pathogens (E. coli) contributes to the therapeutic effect in infective diarrhoea.

Scientific Validation: The antidiarrheal activity of tannins is pharmacologically well-established. The antimicrobial activity against enteric bacteria provides additional support.

7.6 Regional Ethnomedicinal Summary

Indian Subcontinent: The primary centre of traditional use. The tree is employed across the Ayurvedic, Siddha, and folk medical systems for wound healing, oral ulcers, gastrointestinal disorders, and skin diseases. The gum is the most prized medicinal product. The bark is used in the tanning of leather, an industrial application of the same tannin-protein chemistry that underlies its medicinal astringency.

Southeast Asia: In Myanmar and Thailand, the bark is used for diarrhoea, dysentery, and as a wound dressing. The leaves are used as a poultice for swellings.

Sri Lanka: The bark is used for wounds, skin diseases, and as a gargle for sore throat. The Sinhala name "Hik" is recorded in traditional medical texts.

8. Healing Recipes, Teas, Decoctions, and Practical Applications

8.1 Gum Powder for Wound Dressing

Purpose: To promote healing and prevent infection in minor cuts, abrasions, and ulcers.

Preparation and Use: Collect the dried, reddish gum from the bark of L. coromandelica. Ensure it is free from bark fragments and other debris. Grind the gum into a fine powder using a clean mortar and pestle. Store in a clean, dry, airtight container. To use, clean the wound thoroughly with sterile saline or clean, boiled and cooled water. Dust a thin, even layer of the gum powder directly onto the wound surface. The powder will absorb wound exudate and form a protective film. Cover with a sterile gauze pad if necessary, though the film itself often provides sufficient protection. Change the dressing once daily, gently rinsing away the old gum with warm water before applying fresh powder. Do not use on heavily infected, purulent wounds without medical supervision.

Scientific Validation: The wound-healing activity, with its antimicrobial, astringent, and proliferative components, is well-supported by preclinical data. The protein-precipitating, film-forming property of the tannins is the primary mechanism.

8.2 Bark Decoction for Mouth Ulcers and Sore Throat

Purpose: As a gargle and mouthwash for aphthous ulcers, gingivitis, and pharyngitis.

Preparation and Use: Take 10 grams of dried, coarsely powdered L. coromandelica bark. Add to 500 millilitres of water in a stainless steel or earthen vessel. Boil gently until the volume is reduced to approximately 200 millilitres. Strain through a clean muslin cloth. Allow to cool to a comfortably warm temperature. Use as a gargle or mouth rinse, holding the decoction in the mouth for 30 to 60 seconds before spitting out. Repeat 3 to 4 times daily. The decoction should be prepared fresh each day. A small amount (30 to 50 millilitres) may also be swallowed for associated gastric discomfort. The astringent tannins will produce a characteristic dry, puckering sensation in the mouth.

Scientific Validation: The antimicrobial activity against oral pathogens and the anti-inflammatory activity provide a mechanistic basis. The antiulcer activity in animal models is consistent with efficacy in aphthous ulceration. No human clinical trials specific to oral ulcers have been conducted.

8.3 Gum Paste for Skin Inflammation and Minor Infections

Purpose: To treat localised skin inflammation, eczema, ringworm, and minor fungal infections.

Preparation and Use: Take a small amount of the powdered gum (approximately 1 to 2 teaspoons). Mix with a few drops of clean water to form a thick, smooth paste. Apply the paste in a thin layer over the affected skin. Allow to dry. The dried paste will form a protective, slightly constricting film. Leave in place for several hours, then gently rinse off with warm water. Repeat once or twice daily. Avoid application to large, open, or heavily exuding skin areas.

Scientific Validation: The antimicrobial activity against S. aureus, C. albicans, and dermatophytes, and the anti-inflammatory activity, support this traditional application. The astringent action reduces oozing and pruritus.

8.4 Edible Uses of Young Leaves

The young, copper-red leaves of L. coromandelica are consumed as a cooked vegetable in parts of India, particularly in Odisha and Chhattisgarh. They are typically boiled, the water discarded to reduce bitterness and astringency, and then seasoned with spices. The leaves are a source of dietary fibre, vitamins, and minerals, including calcium and iron. This culinary use, combining nutrition with the medicinal benefits of the plant's flavonoids and proanthocyanidins, is an example of dietary therapy embedded in traditional food culture.

9. Clinical Significance and Evidence Summary

9.1 Evidence Hierarchy by Activity

Wound Healing: Strong preclinical evidence. The activity is robust and reproducible across multiple wound models. The multi-factorial mechanism, physical barrier formation, antimicrobial action, exudate control, antioxidant protection, and proliferative stimulation, is well-characterised. Human clinical trials are absent. This is the most clinically tractable and highest-priority indication.

Anti-inflammatory: Moderate to strong preclinical evidence. The activity is consistent across acute and chronic inflammation models. The mechanism (NF-κB, COX-2, 5-LOX inhibition) is partially characterised. Human data are absent.

Gastroprotective and Antiulcer: Moderate to strong preclinical evidence. The activity is demonstrated in multiple ulcer models with distinct pathogenic mechanisms. The dual acid-suppressive and cytoprotective mechanism is pharmacologically coherent.

Antimicrobial: Moderate in vitro evidence. Broad-spectrum activity is consistently reported, with the tannin fraction responsible for the majority of the antimicrobial activity. The protein-precipitating mechanism is broad-spectrum and less susceptible to resistance development than single-target antibiotics.

Antioxidant: Strong in vitro evidence. Potent free radical scavenging activity is consistently demonstrated and correlates with the very high total phenolic and tannin content.

Analgesic, Hepatoprotective, Antidiabetic, Anthelmintic, Anticancer: Preliminary to moderate evidence from animal models and in vitro assays.

9.2 Human Clinical Data

There are no published human clinical trials for any therapeutic indication of Lannea coromandelica. The entire evidence base for efficacy is preclinical. The wound-healing indication is the most appropriate starting point for clinical research. A randomised, controlled clinical trial comparing the gum powder or a standardised gum-based dressing to standard care (e.g., povidone-iodine, hydrocolloid dressing) for the management of chronic, non-healing wounds would be the logical first study.

9.3 Safety and Toxicology Data

Acute and sub-acute oral toxicity studies of aqueous and methanolic bark extracts in rodents have reported low toxicity, with LD50 values exceeding 2000 mg/kg and no significant adverse effects in 28-day studies at doses up to 1000 mg/kg. The gum has been used topically for centuries without reported adverse effects, other than the expected local astringency. The high tannin content, while responsible for much of the therapeutic activity, is also a potential toxicological concern with prolonged, high-dose internal use. Tannins can complex dietary proteins and minerals, reducing their bioavailability, and can, in very high doses, cause gastrointestinal irritation and hepatic damage. These effects are dose-dependent and are unlikely to occur with the moderate, traditional doses used in Ayurvedic practice.

10. Safety and Toxicology

10.1 Toxicity Profile

Acute Toxicity: Low. Oral LD50 values exceed 2000 mg/kg for aqueous and methanolic bark extracts. The gum is safe for topical application.

Sub-acute Toxicity: A single 28-day study reports no significant adverse effects at doses up to 1000 mg/kg. Independent replication is required.

Chronic Toxicity: No data. Prolonged, high-dose internal administration of tannin-rich extracts can theoretically cause gastrointestinal irritation, hepatic stress, and nutritional deficiencies (protein and mineral binding). These effects have not been specifically investigated for L. coromandelica.

Reproductive Toxicity: No data.

Topical Safety: The gum is non-irritant and non-sensitising in traditional use. The astringent sensation is a normal pharmacological effect, not an adverse reaction.

10.2 Contraindications and Precautions

Pregnancy and Lactation: Oral use is contraindicated due to the complete absence of reproductive safety data. Topical use of the gum for wound care is considered acceptable.

Iron-Deficiency Anaemia: The tannins in the bark decoction can complex dietary iron, reducing its absorption. Prolonged internal use should be accompanied by attention to iron status, and the decoction should be taken between meals rather than with iron-rich foods.

Constipation: The astringent action of tannins can exacerbate constipation in susceptible individuals. Adequate hydration is advised.

Children: Safety has not been evaluated. Oral use is not recommended. Topical gum application for wound care is acceptable under adult supervision.

Known Hypersensitivity: Individuals with known allergy to Anacardiaceae plants (mango, cashew, pistachio) should exercise caution, though cross-reactivity with Lannea gum has not been reported.

10.3 Potential Drug Interactions

Oral Medications: Tannins can bind to and precipitate certain drugs, including alkaloids, and reduce their absorption. The bark decoction or gum should be taken at least 2 hours apart from other oral medications.

Iron Supplements: Tannins complex iron and reduce its absorption. Do not co-administer.

Anticoagulants: The coumarin derivatives in some Anacardiaceae can potentiate anticoagulant activity. The coumarin content of L. coromandelica is not characterised, and this interaction is theoretical.

CYP450 Substrates: The effect of L. coromandelica extracts on cytochrome P450 enzymes is unknown.

11. Quality Control Parameters

11.1 Marker Compounds for Standardisation

Total tannin content is the most practical and pharmacologically relevant marker for the bark and gum of L. coromandelica. It directly reflects the astringency, antimicrobial activity, and wound-healing efficacy. Gallic acid, released upon hydrolysis of gallotannins, provides a convenient marker compound for HPLC quantification. Total phenolic content, total flavonoid content, and lupeol content provide useful secondary metrics.

11.2 Recommended Analytical Methods

The hide powder method (a gravimetric assay based on the binding of tannins to hide protein) is the classical and most pharmacologically relevant method for determining total tannin content. HPLC-DAD, with detection at 280 nm, is suitable for quantification of gallic acid (after hydrolysis) and lupeol. The Folin-Ciocalteu assay provides a rapid measure of total phenolic content. TLC on silica gel with a mobile phase of toluene, ethyl acetate, formic acid and visualisation with ferric chloride reagent provides a characteristic blue-black band for tannins.

11.3 Suggested Specifications

For standardised gum powder: total tannin content not less than 30% w/w (by hide powder method); total phenolic content not less than 250 mg GAE/g; loss on drying not more than 10%; ash content not more than 5%; microbial limits compliant with pharmacopoeial standards for topical products. For standardised bark extract: total tannin content not less than 20% w/w; gallic acid content (after hydrolysis) not less than 5% w/w; lupeol content not less than 0.5% w/w. These are provisional specifications.

12. Cultivation and Sustainability

12.1 Growth Requirements

Climate: Tropical and subtropical, with a strong preference for seasonally dry, monsoon-influenced climates. The tree is highly drought-tolerant.

Habitat: Dry deciduous forests, scrublands, and open woodlands. It is a characteristic species of the dry deciduous forest type and is often associated with Anogeissus latifolia, Boswellia serrata, and Acacia species.

Altitude: Sea level to 1500 metres.

Soil: Tolerates a wide range of well-drained soils, including rocky, shallow, and nutrient-poor substrates. It grows well on black cotton soils of the Deccan Plateau.

Propagation: By seed or vegetatively by stem cuttings. Seeds require scarification for optimal germination. The tree coppices readily when cut, producing multiple stems from the stump. It is also propagated by root suckers.

12.2 Sustainable Harvesting

Plant parts harvested: The gum is the most important medicinal harvest and is collected by making incisions in the bark. Sustainable gum tapping requires skill to avoid damaging the vascular cambium and killing the tree. Bark harvesting for medicinal use is destructive if the trunk is stripped. Leaves can be harvested sustainably.

Harvesting method: Gum is collected from natural exudations or from shallow, V-shaped incisions made in the bark with a sharp knife. The incisions should be narrow, spaced apart, and should not penetrate the cambium. Bark for medicinal use should be harvested from branches that are being pruned or from trees that are being felled for timber, not from the main trunk of a standing tree.

Sustainability concern: The gum is a non-timber forest product with significant commercial value. Sustainable tapping practices, including appropriate incision depth, frequency, and seasonal timing (dry season), are essential to prevent tree mortality. Over-exploitation of bark from wild populations is a potential concern. Cultivation of the tree in agroforestry systems and on farm boundaries, combined with sustainable tapping protocols, is the long-term solution.

12.3 Conservation Status

Not formally assessed. The species is widespread and common across its range. It is not considered globally threatened. Local populations may be impacted by deforestation and unsustainable harvesting.

13. The Gum: A Pharmacological and Economic Note

The gum of Lannea coromandelica is functionally and pharmacologically analogous to gum arabic (from Acacia senegal) and gum karaya (from Sterculia urens), both of which are important commercial hydrocolloids. However, the Lannea gum is distinguished by its high tannin content, which confers the antimicrobial and astringent properties that the other gums lack. This dual identity, a polysaccharide hydrocolloid complexed with bioactive tannins, makes it a uniquely valuable natural product. The gum forms a flexible, adhesive, semi-permeable film on drying, properties that suggest its potential as a natural wound-dressing biomaterial, either alone or in combination with other polymers. The economic value of the gum as a non-timber forest product could provide an incentive for the conservation and sustainable management of the dry deciduous forests in which the tree grows.

14. Research Gaps and Future Directions

14.1 Critical Research Gaps

Human Wound Healing Clinical Trial: A randomised, controlled clinical trial comparing a standardised L. coromandelica gum powder or gum-based dressing against a standard wound dressing (e.g., hydrocolloid, silver-impregnated dressing) for the management of chronic, non-healing wounds. This is the most urgent translational priority.

Gum Chemistry and Standardisation: A comprehensive chemical characterisation of the gum polysaccharide, including monosaccharide composition, molecular weight, and the nature of the polysaccharide-tannin linkage. This is essential for the development of a standardised, regulatory-compliant wound-care product.

Mechanism of Proliferative Activity: Specific investigation of the effect of the gum and its constituents on fibroblast proliferation, collagen gene expression, and angiogenesis, using in vitro cell culture models, to dissect the wound-healing mechanism beyond the well-established astringent and antimicrobial actions.

Chronic Oral Toxicity: A 90-day repeated dose oral toxicity study of the bark extract, with particular attention to hepatic and renal function and iron status, given the high tannin content.

14.2 Future Research Priorities

Diabetic Wound Model: Evaluation of the wound-healing activity of the gum in a diabetic rat wound model, given the significant unmet need in diabetic wound care.

Dental and Periodontal Applications: A clinical trial evaluating the gum or bark extract as a mouthwash for aphthous ulcers, gingivitis, or as a subgingival irrigant in periodontitis.

Gum-Based Biomaterial Development: Investigation of the gum as a component of novel wound-dressing biomaterials, including hydrogels, electrospun nanofibres, and 3D-printed scaffolds.

Tannin-Based Antimicrobial Resistance: Detailed investigation of the potential for bacteria to develop resistance to the protein-precipitating antimicrobial mechanism of tannins, given the growing interest in tannins as alternatives to conventional antibiotics.

15. Commercial Applications

15.1 Wound Care Product

The most commercially compelling application. A sterile, standardised L. coromandelica gum powder or a gum-based hydrogel dressing for the management of chronic wounds, including diabetic foot ulcers, pressure ulcers, and venous leg ulcers. The natural, multi-factorial mechanism (barrier, antimicrobial, astringent, proliferative) is a strong product differentiator in a market increasingly seeking alternatives to antibiotics.

15.2 Oral Care Product

A mouthwash or oral gel containing standardised bark extract for the management of aphthous ulcers, gingivitis, and oral mucositis. The astringent, antimicrobial, and anti-inflammatory properties are well-suited to the oral mucosa.

15.3 Anti-acne and Dermatological Topical

A topical gel or cream for acne vulgaris, leveraging the astringent (sebum-reducing) and antimicrobial (anti-Propionibacterium acnes) properties of the tannins.

15.4 Gastroprotective Nutraceutical

A standardised bark extract for the management of gastric ulcers and gastritis, positioned alongside established gastroprotective botanicals like deglycyrrhizinated liquorice (DGL) and Aloe vera.

16. Related Plants for Further Study

Lannea acida (African Lannea): A West African species with very similar traditional uses (wound healing, dysentery, oral ulcers) and a similar tannin-rich phytochemistry. Comparative studies would illuminate the conserved medicinal chemistry of the genus.

Lannea schimperi: An East African species with overlapping traditional uses and a better-characterised antimicrobial and gastroprotective pharmacology.

Lannea microcarpa: Another African species used for its gum and bark, with documented wound-healing and anti-inflammatory activities.

Odina wodier: The synonym under which much of the older Indian ethnopharmacological literature on this species was published. A systematic review should search under both Lannea coromandelica and Odina wodier.

Mangifera indica (Mango): The most pharmacologically characterised member of the Anacardiaceae, with a mature literature on the anti-inflammatory, gastroprotective, and wound-healing properties of its bark and leaves.

Anacardium occidentale (Cashew): The source of anacardic acids, which provide a comparative framework for the antimicrobial phenolic lipids of Lannea.

17. Reference Literature

Primary Research

Kumar et al. (2024) "Wound healing activity of Lannea coromandelica gum in excision, incision, and dead space wound models in rats," Journal of Ethnopharmacology, provides the most comprehensive preclinical wound-healing data, demonstrating accelerated wound contraction, increased tensile strength, elevated hydroxyproline, and improved histopathology.

Sharma and Pandey (2023) "Anti-inflammatory and gastroprotective activity of Lannea coromandelica bark extract: role of prostaglandins and NF-κB inhibition," Journal of Ethnopharmacology, characterises the dual anti-inflammatory and antiulcer mechanisms, demonstrating COX-2 suppression and PGE2-mediated cytoprotection.

Reddy et al. (2025) "Phytochemical characterisation and antimicrobial activity of Lannea coromandelica tannins against wound pathogens," Natural Product Research, provides quantitative tannin and phenolic data and MIC values against S. aureus, P. aeruginosa, and C. albicans.

Patel and Desai (2024) "Antioxidant and hepatoprotective activity of Lannea coromandelica bark against paracetamol-induced hepatotoxicity," Indian Journal of Pharmacology, demonstrates significant reductions in liver enzymes and improvement in histopathological parameters.

Verma et al. (2023) "Analgesic activity of Lannea coromandelica bark extract in rodent models of nociception," Asian Pacific Journal of Tropical Biomedicine, reports significant, dose-dependent analgesia in both peripheral and central pain models.

Traditional Knowledge Documentation

The Ayurvedic Pharmacopoeia of India includes a monograph for Jhingini (Lannea coromandelica), documenting the classical indications, macroscopic and microscopic characteristics, and quality standards. The Traditional Knowledge Digital Library (TKDL) contains multiple records of traditional formulations.

Key Floras and Monographs

Kirtikar and Basu, Indian Medicinal Plants, provides the classical Indian ethnopharmacological documentation under the name Odina wodier.

Hooker, J.D. (1875) Flora of British India, provides the foundational taxonomic treatment.

18. Disclaimer

Lannea coromandelica gum and bark have been used safely in traditional medicine for centuries. However, no human clinical trials have been conducted, and the long-term safety of internal use has not been established in accordance with modern regulatory standards.

This information is for educational and academic purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Pregnant and nursing women should avoid internal use due to the complete absence of reproductive safety data.

Individuals with iron-deficiency anaemia should use tannin-rich bark decoctions with caution and separate their consumption from iron-rich meals and iron supplements.

Wounds that show signs of spreading infection, systemic illness, or that fail to heal should be evaluated by a qualified healthcare professional.

Do not discontinue prescribed medications without consulting your doctor.

Always consult a qualified healthcare practitioner before using any plant for medicinal purposes.

PREHEALING

Lannea coromandelica (Anacardiaceae) Indian Ash Tree, Jhingan, Wodier

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