Alstonia scholaris

Identity, Nomenclature, and Botanical Profile

Scientific Classification and Synonyms

Alstonia scholaris (L.) R.Br. (family Apocynaceae) is an evergreen tropical tree native to the Indian subcontinent and Southeast Asia, possessing grayish rough bark and a milky sap rich in poisonous alkaloids. The plant was initially called Echites scholaris, Echites pala, and Tabernaemontana alternifolia before receiving its current accepted name. The genus Alstonia comprises about 60 species throughout the world, of which about 6 species occur in India.

Common Names and Vernacular Designations

Alstonia scholaris is known by various names, including Devil's Tree, White Cheese Wood, Milkwood Pine, Kilky Pine, Blackboard Tree, and Dita Bark in English. The epithet scholaris was given to this species because its wood was historically used for making blackboards. It is also sometimes called the Devil's Tree due to severe allergic reactions caused by its pollens during the flowering season. In Indian traditional medicine, the plant is widely known as Saptaparna (seven-leaved) or Saptachada.

Natural Source and Morphology

The plant is grown in the lowland and mountain rainforests of India, the Asia-Pacific, and Southern regions. Alstonia scholaris (L.) R. Br. is extensively used in traditional medicinal systems of India, Thailand, Malaysia, Philippines, China, Africa, and Australia. An evergreen tree that grows in tropical regions of Asia, it can attain considerable heights and produces white-colored flowers.

Plant Parts Used and Common Preparations

The plant contains a wide variety of phytochemical components in its stem, bark, leaves, roots, and fruits, among other plant parts. The bark is the most widely employed part, with decoctions mostly prepared from the bark used to treat a variety of diseases, of which the most important historically is malaria. From ancient times, it has been an important medicinal plant used to treat health conditions such as stomach ache, diarrhea, and abdominal disorders, using various preparations including decoctions and powders. The leaves are considered a therapy for respiratory diseases including whooping cough, chronic bronchitis, and chronic obstructive pulmonary disease; the leaf crude water extract has been prepared as a tablet or granule and sold as therapeutic drugs for tracheitis and the common cold. The latex is specifically employed for wound healing, ulcers, and as an analgesic in rheumatoid arthritis.

Traditional and Historical Uses

Ayurvedic Medicine (Indian Subcontinent)

The plant is used in Ayurvedic, Unani, and Siddha types of alternative medicinal systems. In Ayurveda, it is used as a bitter and astringent herb for treating skin disorders, malarial fever, urticaria, chronic dysentery, diarrhea, and snakebite. Alstonia scholaris is used in various Ayurvedic preparations including Saptaparnasatvadi vati, Saptachadadi vati, Saptacchadadi kvatha, and Saptaparna ghanasara, primarily for whooping cough, malaria, jaundice, gastric complaint, headache, asthma, stomach ache, and fever.

Alstonia scholaris is one of the ingredients in the antimalarial drug Ayush-64, prepared by the Central Council for Research in Ayurvedic Sciences (CCRAS). The Ayush-64 formulation combines Saptachada (Alstonia scholaris R.Br.) with Katuka (Picrorhiza kurroa), Kirata Tiktaka (Swertia chirata), and Kuberakshi (Caesalpinia bonducella).

Traditional Chinese Medicine and Dai Ethnopharmacy

Alstonia scholaris is an important constituent of Chinese medicine since time immemorial. Its leaves have long been used in "Dai" ethno-pharmacy for the treatment of respiratory diseases in Yunnan Province, People's Republic of China. Alstonia scholaris (Apocynaceae) has been traditionally used for treatment of respiratory diseases in "Dai" ethnopharmacy for hundreds of years, especially for cough, asthma, phlegm, and chronic obstructive pulmonary disease; formulas including the leaf extract have also been prescribed in hospitals and sold over retail pharmacies.

Alstonia scholaris has been historically used in "Dai" ethnopharmacy to treat chronic respiratory diseases, and the leaf extract was developed as a commercially available traditional Chinese medicine used to relieve tracheitis and cold symptoms, prescribed in hospitals and sold over the counter in drug stores.

Southeast Asia, Africa, and the Pacific

The plant is used in traditional, Ayurvedic, Unani, Homeopathy, and Siddha/Tamil types of alternative medicinal systems against different ailments such as asthma, malaria, fever, dysentery, diarrhea, epilepsy, skin diseases, and snakebite. Literature shows that Alstonia scholaris is useful in treating malaria, stomach disorders, dyspepsia, leprosy, skin diseases, tumors, chronic and foul ulcers, asthma, and bronchitis. In other parts of the world, it is used as a source of cure against bacterial infection, malarial fever, toothache, rheumatism, snakebite, dysentery, and bowel disorders.

Key Constituents and Active Compounds

Overview of Phytochemical Classes

Researchers have extracted more than 300 chemicals from the Alstonia genus. Alkaloids, flavonoids, coumarin derivatives, leucoanthocyanin, reducing sugars, simple phenolics, steroids, saponins, and tannins are all present in A. scholaris. The plant displays an abundance of metabolites, including tocopherols, polyunsaturated fatty acids, carboxylic acids, proteins, and carbohydrates.

Bark Alkaloids

The bark contains several alkaloids including ditamine, echitamine, echitenine, echicaoutchin, echicerin, echitin, echitein, echiretin, ditain, losbanine, 6,7-secoangustilobine B, N_b-demethyl echitamine, 17-O-acetyl echitamine, picraline deacetyl, lupeol, β-sitosterol, alstonidine, alstonine, villalstonine, and macrocarpamine. The stem bark serves as the primary source of these alkaloids, with total alkaloid content reported at approximately 0.2% of dry weight. Among them, echitamine stands out as the major indole alkaloid in the bark, which is used in traditional formulations such as Ayush-64.

Leaf Alkaloids

The leaves contain alkaloid compounds including scholaricine, 19-epischolaricine, vallesamine, picrinine, (19,20)E-alstoscholarine, (19,20)Z-alstoscholarine, 5-methoxyaspidophylline, picralinal, 5-methoxystrictamine, scholarisine A, scholarisines H-O, (±)-scholarisine II, alstorisine A, scholarisines B-G, normavacurine-21-one, 5-hydroxy-19,20-E-alschomine, 5-hydroxy-19,20-Z-alschomine, altoscholarisines A-J, alstoniascholarines A-K, and alstoniascholarines L-Q, among others. In the leaves, picrinine, scholaricine, vallesamine, and 19-epischolaricine have been proved to be the major bioactive alkaloids.

Stem Bark Additional Alkaloids

17-O-acetylechitamine, echitaminic acid, alstonoside, akuammiginone, echitamine, scholarisines B-G, scholareins A-D, echitamidine N-oxide, isoboonein, and loganin are components of the stem bark. The bark of the plant also contains echicaoutchin, echitenine, and echitin in crystallized scales, echicerin in acicular crystals, echitein in rhombic prisms, and echiretin, an amorphous substance that resembles an alkaloid, alongside fatty acid and fatty resinous substances.

Non-Alkaloid Constituents

The flowers of Alstonia scholaris contain n-hexacosane, lupeol, β-amyrin, palmitic acid, and ursolic acid. Five compounds — triterpenes and sterols — were isolated from the hexane fraction of the alcohol extract of the leaves, identified as 4α,14α,24-trimethyl-9β,19-cyclo-5α-cholest-24(29)-en-3β-ol, stigmasterol, betulin, betulinic acid, and α-amyrin acetate. The root and root bark contain α-amyrin, α-amyrin acetate, lupeol acetate, stigmasterol, β-sitosterol, and campesterol and its isomer. Among non-alkaloid phytoconstituents, isookanine-7-O-alpha-rhamnopyranoside, a new flavone glycoside, and alstonoside, a secoiridoid glycoside, have also been reported.

Genome and Biosynthetic Pathways

Akuammiline alkaloids are a class of monoterpenoid indole alkaloids (MIAs) in A. scholaris; more than 300 compounds with various pharmacological activities have been identified. Echitamines exhibit both in vitro and in vivo cytotoxicity, while strictamines inhibit the transcription factor nuclear factor κB (NF-κB). Additionally, the renal cortex protein SGLT2 is inhibited by derivatives of picraline, and aspidophylline A reverses drug resistance in cancerous cell lines. Biogenetically, these akuammiline alkaloids are derived from geissoschizine, a key intermediate in the biosynthetic pathway of MIAs.

Established Mechanisms of Action

Anti-Inflammatory and Analgesic Mechanisms

The alkaloid fraction of Alstonia scholaris leaves — the three main alkaloids picrinine, vallesamine, and scholaricine — may produce anti-inflammatory and analgesic effects peripherally based on in vivo assays; in vitro tests, these alkaloids exhibited inhibition of inflammatory mediators (COX-1, COX-2, and 5-LOX). In pharmacological studies, these alkaloids triggered β2-adrenergic receptor (β2AR) activation and inhibited nuclear factor-κB (NF-κB) activities in vitro. Pharmacological studies showed methanol extract at 200 mg/kg significantly inhibits carrageenan rat paw edema compared with edema inhibition by the standard drug indomethacin at 10 mg/kg.

Antitussive and Bronchodilatory Mechanisms

Various laboratory-identified biological activities of the total alkaloid extract include antitussive, anti-asthmatic, expectorant, analgesic, anti-inflammatory, anti-airway inflammation, anti-allergic asthma, anti-postinfectious cough effects, and alleviation of emphysema and pulmonary fibrosis; the anti-inflammatory effects are achieved by triggering the β2-adrenergic receptor and inhibiting nuclear factor-κB expression. The alkaloids fraction is the antitussive, anti-asthmatic, and expectorant component of Alstonia scholaris leaf; picrinine, the main antitussive and anti-asthmatic compound, has been identified as a quality control marker for products derived from the leaf.

Antiplasmodial Mechanisms

Numerous alkaloids from Alstonia scholaris have been shown to be effective against malaria, including the bisindole alkaloids macrocarpamine and villalstonine, which are active against the multidrug-resistant K1 strain of Plasmodium falciparum. Alstonia scholaris has potent schizonticidal and antiplasmodial properties against P. falciparum, which help reduce malarial fever.

Antipsychotic and CNS Mechanisms (Alstonine)

Alstonine has demonstrated a psychopharmacological profile in mouse models more akin to atypical antipsychotic medications. Its anxiolytic activity is mediated by 5-HT2A/2C serotonin receptors, which suggests it may be useful in reducing negative symptoms associated with schizophrenia.

Anticancer Mechanisms

Echitamine chloride, an indole alkaloid extracted from the bark of A. scholaris, has been shown to have potential as an anticancer agent; it effectively altered the defective microsomal drug detoxifying system observed in sarcoma-180-induced mice when administered subcutaneously at a dosage of 5 mg/kg body weight. Echitamine is reported as a lipase inhibitor, antiproliferative agent, and targeted for cancer chemotherapy.

Immunomodulatory Mechanisms

The bark extract of A. scholaris has immune-stimulating effects; aqueous extracts at low dose induced cellular immune response while at high dose inhibited the delayed type of hypersensitivity reaction.

Scientific Evidence by Health Area

1. Respiratory Disease (Strongest and Most Clinically Advanced Evidence)

Animal/Preclinical Evidence: An emphysema model was induced by intratracheal instillation of porcine pancreatic elastase; following 30 consecutive days of administration of total alkaloids and four main alkaloid components (scholaricine, 19-epischolaricine, vallesamine, and picrinine), cytokine levels, histopathological parameters, and protein expression in lung tissues were examined. Administration of these compounds effectively inhibited inflammatory cell accumulation and invasion in lung tissue and relieved pulmonary tissue injury.

Regulatory and Drug Development Status: Total alkaloids (TA) extracted from A. scholaris leaves were approved as a new botanical drug (No. 2011L01436) by the China Food and Drug Administration, due to strong pharmacological activity, low toxicity, and a stable extraction process. Total alkaloids of A. scholaris have been registered as an investigational new botanical drug (No. 2011L01436) and approved for clinical trials (Phase I and II) by the Chinese National Medical Products Administration.

Phase I Clinical Trial (Human Evidence): The Capsule of Alkaloids from the Leaf of Alstonia scholaris (CALAS) (No. 2011L01436) is a new investigational botanical drug for bronchitis, post-infectious cough, and asthma. Subjects were assigned to eight cohorts, each receiving CALAS or placebo in single ascending doses of 8, 40, 120, 240, 360, or 480 mg, or in multiple ascending doses of 40 or 120 mg three times daily for 7 days, with each cohort containing two placebo subjects; 62 enrolled volunteers completed the study and no serious adverse events or clinically significant changes in vital signs, electrocardiography, or Doppler ultrasonography were observed. CALAS was safe and well-tolerated with no unexpected or clinically relevant safety concerns up to a single dose of 360 mg and three times daily for 7 days up to 120 mg in healthy Chinese volunteers, supporting further Phase II studies.

Phase II Pilot Study in Acute Bronchitis (Human Evidence): Oral CALAS was assessed in a randomized, double-blind, placebo-controlled trial in which 55 eligible patients were randomly assigned to four cohorts to receive 20, 40, or 80 mg of CALAS three times daily for seven days, or placebo; this was described as the first study to evaluate clinical efficacy and explore potential biomarkers related to the CALAS therapeutic mechanism of acute bronchitis using a clinical trial combined with metabolomics, providing a basis for further research on clinical efficacy and optimal dosing regimens. This study identified changes in lysophosphatidylcholine, lysophosphatidylethanolamine, and amino acids as possible indirect markers in the treatment of acute bronchitis, and there were no serious adverse effects in clinical trials.

Evidence Strength: The respiratory evidence represents the most developed body of clinical research for this plant. Phase I and early Phase II data exist in humans. However, the Phase II study was exploratory and small (55 patients), and broader confirmatory randomized controlled trials in larger patient populations are not yet available. The preclinical evidence base for antitussive, expectorant, anti-asthmatic, and anti-emphysema effects is extensive and mechanistically grounded, but the overall clinical evidence remains preliminary.

2. Antimalarial Activity

Several studies have demonstrated the antiplasmodial action of alkaloids; the antimalarial potential of Alstonia scholaris has not been fully elucidated despite its high alkaloid concentration, with investigations revealing more potential from bark methanol extract. Alstonia scholaris has potent schizonticidal and antiplasmodial properties against P. falciparum demonstrated in in vitro study. A. scholaris is used in the commercial formulation Ayush-64.

Evidence Strength: Antimalarial evidence is largely preclinical (in vitro and animal studies). Clinical evidence derives principally from the multi-ingredient Ayush-64 formulation rather than A. scholaris as an isolated agent, making attribution of effect difficult. No standalone human clinical trial exclusively testing A. scholaris extract against malaria has been identified in the peer-reviewed literature.

3. Anticancer Activity

In China and South Asia, Alstonia scholaris has been historically used to treat infectious diseases; although various pharmacological activities have been reported, the anti-lung cancer components of A. scholaris have not yet been fully identified. For anticancer effects, alkaloids like echitamine demonstrate cytotoxicity against tumor cell lines such as S-180 sarcoma and A549 lung cells, inducing apoptosis in preliminary studies, but further human trials are needed to validate efficacy. The anticancer properties of this medicinal plant were evaluated: tumor incidence, yield, burden, and cumulative number of papillomas were higher in the carcinogen-treated control compared to animals treated with A. scholaris extract; a significant increase in reduced glutathione, superoxide dismutase, and catalase level, along with a decrease in lipid peroxidation, was observed in ASE-administered experimental groups versus carcinogen-treated controls.

Evidence Strength: Anticancer evidence is entirely preclinical — restricted to in vitro cell line studies and animal models. No human clinical trials have been conducted for oncological indications. This area is considered preliminary.

4. Anti-inflammatory and Analgesic Activity

A. scholaris extracts and alkaloids have shown antitussive, anti-asthmatic, expectorant, analgesic, and anti-inflammatory effects, as well as airway anti-inflammation in vivo. The leaves of A. scholaris, containing high flavonoid and phenolic components, are used to prevent oxidative stress-mediated hepatic, cardiac, neuronal, and renal injuries.

Evidence Strength: Anti-inflammatory and analgesic evidence is from in vitro enzyme inhibition assays and rodent models. No dedicated human clinical trials for pain or general inflammation as primary endpoints have been identified.

5. Hepatoprotective Activity

The hepatoprotective effect of Alstonia scholaris R. Br. on liver injuries induced by carbon tetrachloride (CCl4), β-D-galactosamine, acetaminophen, and ethanol has been investigated using various fractions of the extract.

Evidence Strength: Hepatoprotective evidence is preclinical, based on experimentally induced hepatotoxicity in rodent models. No clinical evidence in humans has been identified.

6. Antioxidant Activity

Ethanolic extract of A. scholaris at various concentrations in in vitro tests was found to have significant (P = 0.01) free radical scavenging and metal ion chelating properties. The plant A. scholaris is reported to possess in vitro nitric oxide scavenging activity in preliminary studies.

Evidence Strength: Antioxidant evidence is restricted to in vitro assays. Clinical translation has not been established.

7. Antimicrobial Activity

Antiviral (RSV, HSV-1, H1N1) and antibacterial (beta-hemolytic streptococcus) properties of the total alkaloid extract have been described in in vitro and in vivo studies, which may relate to causative agents of acute respiratory infections. Bark and leaf extracts show in vitro antibacterial activity against pathogens including methicillin-resistant Staphylococcus aureus (MRSA), supporting traditional uses for infections.

Evidence Strength: Antimicrobial evidence is from in vitro and animal studies. No independent human clinical trials for antimicrobial indications have been identified.

8. CNS / Antipsychotic Activity (Alstonine)

Among the isolated compounds, the indoloquinolizidine alkaloid alstonine has attracted research interest due to its numerous biological potentials, including antipsychotic, antiplasmodial, anticancer, anxiolytic, and antidiabetic activities. Alstonine has demonstrated a psychopharmacological profile in mouse models more akin to atypical antipsychotic medications; its anxiolytic activity is mediated by 5-HT2A/2C serotonin receptors, suggesting usefulness in reducing negative symptoms associated with schizophrenia.

Evidence Strength: CNS evidence is exclusively from animal (rodent) behavioral models. No human clinical trials for CNS or antipsychotic indications have been identified.

Dosage Forms and Doses Reported in Studies

Investigational Drug Formulation (CALAS)

In the Phase I dose-escalation trial, subjects received CALAS or placebo in single ascending doses of 8, 40, 120, 240, 360, or 480 mg, or in multiple ascending doses of 40 or 120 mg three times daily for 7 days, with each cohort containing two placebo subjects. Whether given as a single dose as high as 360 mg or 120 mg three times per day for seven days to healthy volunteers, these alkaloids were observed to be safe and well-tolerated with no unanticipated or clinically relevant safety issues.

Dosages in Patient Studies

In the acute bronchitis Phase II trial, 55 eligible patients were randomly assigned to four cohorts to receive 20, 40, or 80 mg of CALAS three times daily for seven days, or placebo; each CALAS cohort included 15 subjects, and the placebo group included 10 subjects.

Preclinical Anti-Inflammatory Dosing

In anti-inflammatory animal studies, methanol extract at 200 mg/kg significantly inhibited carrageenan rat paw edema compared with edema inhibition by standard drug indomethacin at 10 mg/kg. Echitamine chloride administered subcutaneously at a dosage of 5 mg/kg body weight effectively altered the defective microsomal drug detoxifying system in sarcoma-180-induced mice.

Traditional and Commercial Preparations

The leaf crude extract, used for relieving tracheitis and cold symptoms, was approved as a commercial formulation by the State Food and Drugs Administration of China. In Ayurvedic tradition, the plant is used in decoction (kwatha) or powdered bark (churna) form. The total alkaloids extract (TA) is obtained from the leaves of A. scholaris by extraction with ethyl acetate, with indole alkaloid content reported at more than 50%.

Body Systems and Health Areas Associated with Alstonia scholaris

• Respiratory System: Alstonia scholaris is widely used to treat respiratory tract diseases, such as cough, asthma, phlegm, and chronic obstructive pulmonary disease.
• Gastrointestinal System: Literature suggests Alstonia scholaris is useful in treating abdominal disorders, dyspepsia, chronic dysentery, and helminthiasis.
• Immune System: It has been reported as immunomodulatory, supporting traditional uses for infection.
• Liver / Hepatic System: Preclinical studies have shown hepatoprotective activity.
• Integumentary (Skin) System: In various Indian traditional systems, the leaves, latex, and bark of this tree are used to treat skin conditions such as leprosy, and chronic ulcers.
• Reproductive System: Alstonia scholaris holds pharmacological potential for relieving various ailments including reproductive problems due to various active phytochemicals.
• Central Nervous System: Alstonine, isolated from the plant, has attracted research interest for antipsychotic and anxiolytic properties.
• Oncology (Preclinical): A. scholaris is observed to possess antimutagenic, anticancer, and chemopreventive activity in preclinical study.

Safety Considerations

Acute Toxicity

The acute toxicity test was conducted using Sprague-Dawley rats; the methanolic extract of Alstonia scholaris stem bark was administered in a single dose of 2000 mg/kg via oral gavage; the plant was found to be non-toxic at this dose.

Sub-Acute and High-Dose Toxicity

In the sub-acute toxicity study, SD rats received three doses of ASME (250, 500, and 1000 mg/kg) for 28 days via oral gavage; significant variations in body weight and hematological and biochemical parameters were observed at doses of 500 and 1000 mg/kg, with the death of two female rats recorded at the highest dose; histopathological studies revealed slight degeneration and centrilobular necrosis in the liver most expressed in the highest-dose group. While a single dose and short-term oral intake caused no toxicity up to 2000 mg/kg, toxic effects manifested in long-term treatment at the highest doses (500 and 1000 mg/kg); the long-term toxic effect was found to be associated with alterations in hematological compositions and end-organ damage to the liver, and prolonged use of high doses of ASME orally should be discouraged.

The observed toxic effect at high doses may be due to the presence of echitamine; at high doses, A. scholaris exhibited marked damage to all the major organs of the body.

Preclinical Genotoxicity and Safety Pharmacology

Indole alkaloids with or without liver S9-induced metabolic activation showed no genotoxicity in the Ames test, mammalian chromosomal aberration test, or micronucleus test, and no adverse effects in any of the nerve, respiratory, and cardiovascular systems were induced as determined using the safety pharmacology core battery; these results met the requirements for regulatory safety submission as defined by the China Food and Drug Administration (CFDA), supporting a clinical trial application.

In the chronic toxicity study of dogs with a range of doses of indole alkaloids (20, 60, and 120 mg/kg/bw), there were no toxic symptoms except for emesis and drooling in the majority of animals in the 120 mg/kg/bw treatment group.

Human Phase I Safety

Sixty-two enrolled volunteers completed the Phase I study and no serious adverse events and no clinically significant changes in vital signs, electrocardiography, and upper abdominal Doppler ultrasonography were observed. Pharmacokinetic, metabolomic, and therapeutic data as well as clinical safety and tolerability evaluations of CALAS in clinical populations have demonstrated a reliable safety profile, only showing minor, transient adverse reactions.

Allergy / Pollen Reactivity

The plant is sometimes called the Devil's Tree due to severe allergic reactions caused by its pollens during the flowering season.

Adulteration Risk

Because of phenotypic similarities with Alstonia macrophylla, Alstonia scholaris is often adulterated with the former; in India, despite its limited distribution, the bark of Alstonia macrophylla is used as a substitute for Alstonia scholaris bark in herbal pharmaceutical preparations.

References

• Unveiling the ethnomedicinal potential of Alstonia scholaris (L.) R. Br.: A comprehensive review on phytochemistry, pharmacology and its applications — ScienceDirect (2024)
• Alstonia scholaris Linn. R. Br.: An Assessment of its Botany, Conventional Utilization, Phytochemistry and Pharmacology — Pharmacognosy Reviews (2023)
• Alstonia scholaris — ScienceDirect Topics Overview
• The safety and tolerability of alkaloids from Alstonia scholaris leaves in healthy Chinese volunteers: a single-centre, randomized, double-blind, placebo-controlled phase I clinical trial — PMC / Pharmaceutical Biology (2021)
• The clinical population pharmacokinetics, metabolomics and therapeutic analysis of alkaloids from Alstonia scholaris leaves in acute bronchitis patients — ScienceDirect / Phytomedicine (2022)
• Pharmacological evaluation of Alstonia scholaris: anti-tussive, anti-asthmatic and expectorant activities — PubMed / Journal of Ethnopharmacology (2010)
• Airways antiallergic effect and pharmacokinetics of alkaloids from Alstonia scholaris — ScienceDirect / Phytomedicine (2017)
• Effects of total alkaloids from Alstonia scholaris (L.) R. Br. on ovalbumin-induced asthma mice — ScienceDirect / Journal of Ethnopharmacology (2023)
• Acute and Sub-Acute Toxicity Evaluation of the Methanolic Extract of Alstonia scholaris Stem Bark — PMC (2017)
• Anticarcinogenic and antimutagenic activity of Alstonia scholaris on the albino mice bone marrow cells and peripheral human lymphocyte culture — PMC (2016)
• The evaluation of the acute toxicity and long term safety of hydroalcoholic extract of Sapthaparna (Alstonia scholaris) in mice and rats — PubMed / Toxicology Letters (2004)
• Chromosome-level Alstonia scholaris genome unveils evolutionary insights into biosynthesis of monoterpenoid indole alkaloids — PMC (2024)
• Anti-Proliferative Activity of Triterpenoids and Sterols Isolated from Alstonia scholaris against Non-Small-Cell Lung Carcinoma Cells — PMC (2018)
• Review of the phytochemical, pharmacological and toxicological properties of Alstonia Scholaris Linn. R. Br (Saptaparna) — Chinese Journal of Integrative Medicine / Springer (2012)
• The therapeutic value of alstonine: An updated review — ScienceDirect / South African Journal of Botany (2022)
• Traditional uses, chemical composition and pharmacological activities of Alstonia R. Br. (Apocynaceae): A review — Arabian Journal of Chemistry (2023)
• Pharmacokinetics and safety evaluation in healthy Chinese volunteers of alkaloids from leaf of Alstonia scholaris: A multiple doses phase I clinical trial — ScienceDirect / Phytomedicine (2019)
• Alstonia scholaris R.Br. (Apocynaceae) — Journal of Applied Pharmaceutical Science
• Anti-microbial Effects In Vitro and In Vivo of Alstonia scholaris — Natural Products and Bioprospecting (2021)
• Indole alkaloids from leaves of Alstonia scholaris (L.) R. Br. protect against emphysema in mice — ResearchGate / Journal of Ethnopharmacology (2020)