Hermetica Superfood Encyclopedia
The Short Answer
Tectona grandis leaf extracts contain the diterpenes (+)-Eperua-8,13-dien-15-oic acid and (+)-Eperua-7,13-dien-15-oic acid, alongside phenolics, flavonoids, and tannins, which act through inhibition of 5α-reductase, suppression of pro-inflammatory cytokines, and free-radical scavenging. In vitro studies demonstrate that the leaf extract inhibits 5α-reductase with an IC₅₀ of 9.57 ± 0.09 μg/mL and suppresses IL-6 production in LPS-stimulated macrophages with an IC₅₀ of 6.554 ± 0.277 μg/mL, suggesting potential applications in androgenetic alopecia and inflammatory conditions.
CategoryHerb
GroupSoutheast Asian
Evidence LevelPreliminary
Primary KeywordTectona grandis benefits
Teak — botanical close-up
Health Benefits
**5α-Reductase Inhibition (Androgenetic Alopecia)**
The leaf extract inhibits the enzyme 5α-reductase with an IC₅₀ of 9.57 ± 0.09 μg/mL in vitro; the isolated diterpenes (+)-Eperua-8,13-dien-15-oic acid (IC₅₀ 14.19 ± 2.87 μM) and (+)-Eperua-7,13-dien-15-oic acid (IC₅₀ 14.65 ± 0.31 μM) are the principal active agents, offering a potential botanical alternative for DHT-mediated hair loss.
**Anti-Inflammatory Activity**
Ethanolic leaf extracts suppress nitric oxide production in LPS-induced RAW 264.7 macrophages (IC₅₀ 12.100 ± 0.885 μg/mL) and inhibit the pro-inflammatory cytokines IL-1β (IC₅₀ 8.365 ± 0.520 μg/mL) and IL-6 (IC₅₀ 6.554 ± 0.277 μg/mL), indicating broad innate immune modulation.
**Antioxidant Protection**
Mature leaf extracts exhibit the highest antioxidant capacity, attributed to phenolic compounds (8.751 ± 0.018 mg GAE/g DW), flavonoids (0.359 ± 0.017 mg QE/g DW), and condensed tannins (0.303 mg CE/g DW) including quercetin and gallic acid, which scavenge reactive oxygen species and reduce oxidative stress.
**Wound Healing Support (Traditional)**
Thai traditional medicine employs teak leaves topically for wound management, with the tectoquinone content and astringent tannins contributing to tissue protective and antimicrobial actions that may facilitate skin barrier repair.
**Antibacterial Activity**
Ethyl acetate and ethanolic leaf extracts containing alkaloids (3.72–4.16%), tannins (2.16–3.72%), and saponins (1.45–1.83%) have demonstrated activity against respiratory bacterial pathogens in preliminary phytochemical validation studies, suggesting a role in traditional respiratory infection management.
**Hepatoprotective and Cytoprotective Potential**
GC-MS profiling has identified phytol and n-decanoic acid in leaf extracts; phytol is a known inducer of antioxidant and anti-apoptotic pathways, and compound 2 (Eperua-7,13-dien-15-oic acid) maintains greater than 80% cell viability at concentrations up to 100 μg/mL, supporting a favorable cytotoxic safety margin.
**Termicidal and Antifungal Defense Compounds**
Heartwood extractives including lariciresinol, tectonoelins A and B, and anthraquinones confer resistance to wood-degrading fungi and termites; these same compounds show preliminary bioactivity in microbiological assays, pointing to potential antimicrobial applications beyond timber preservation.
Origin & History
Natural habitat
Tectona grandis L.f. is native to the tropical forests of South and Southeast Asia, with its natural range spanning Myanmar, Thailand, Laos, and India, and it has been extensively cultivated across Java, Indonesia, and other equatorial regions for centuries. The tree thrives in well-drained, fertile soils at elevations up to 1,000 meters, requiring distinct wet and dry seasons for optimal growth. Traditionally regarded as a premium timber species, teak plantations have expanded across tropical Africa and Latin America, though medicinal research has focused primarily on wild and plantation-grown specimens from Thailand and Indonesia.
“Tectona grandis occupies a position of extraordinary cultural and economic importance across South and Southeast Asia, where it has been cultivated for over two millennia primarily as a premier hardwood timber prized for shipbuilding, temple construction, and royal architecture in Myanmar, Thailand, and India. In Thai traditional medicine, the leaves have been employed as a topical remedy for wound healing, with the astringent tannins and resinous compounds serving as natural antimicrobials and tissue-protective agents, a practice that aligns with the documented phytochemical profile of the leaves. Tectoquinone, a naturally occurring anthraquinone in teak heartwood, has been noted as a bioactive marker associated with the wood's legendary durability and has attracted interest in pharmacological research as a result of its structural pharmacophore. The tree holds religious significance in Hindu and Buddhist traditions, frequently planted near temples and used in sacred ceremonies, and its association with longevity and structural integrity has historically extended—by cultural analogy—to folk attributions of medicinal strength.”Traditional Medicine
Scientific Research
The available evidence base for Tectona grandis leaf bioactivity is entirely preclinical, comprising in vitro enzyme inhibition assays, macrophage cell-line models (RAW 264.7), and phytochemical characterization studies, with no published human clinical trials or controlled animal intervention studies identified as of the latest literature review. Insumrong et al. (2022) provided the most pharmacologically detailed dataset, reporting IC₅₀ values for 5α-reductase inhibition, nitric oxide suppression, and cytokine inhibition from isolated diterpenes and crude ethanolic extracts, but the study design precludes extrapolation of effective doses to humans. Phytochemical screening studies from Indonesian and Thai research groups have quantified phenolic, flavonoid, and tannin contents using standardized colorimetric assays and confirmed trace heavy metal safety (Cd 0.001–0.004 mg/kg; As 0.012–0.018 mg/kg; Pb undetectable), adding regulatory-relevant safety data. The overall evidence level is preliminary; while the mechanistic rationale is scientifically coherent, translation to clinical efficacy requires dose-escalation pharmacokinetic studies, in vivo animal trials, and ultimately randomized controlled human trials before any therapeutic claims can be substantiated.
Preparation & Dosage
Traditional preparation
**Ethanolic Leaf Extract (Research Grade)**
Prepared by macerating dried mature leaves in 70–95% ethanol; tested in vitro at concentrations of 50–100 μg/mL with acceptable cytotoxicity profile; no human dose established.
**Ethyl Acetate Extract**
Yields higher flavonoid fractions (5.89–6.21%); used in antibacterial and phytochemical studies; no standardized human dosage available.
**Microwave-Assisted Extraction (MAE)**
Emerging preparation method optimized for polyphenol yield from mature leaves; reported to improve extraction efficiency over conventional maceration; laboratory scale only.
**Traditional Topical Application (Thai Medicine)**
Leaves are prepared as a poultice or decoction for direct wound application; specific ratios and preparation protocols are not formally documented in the reviewed literature.
**Leaf Maturity Consideration**
751 mg GAE/g DW) and antioxidant activity compared to young leaves; any preparation intended to maximize bioactivity should specify mature leaf material
Mature leaves consistently yield higher phenolic content (8..
**Standardization**
No commercial standardization percentages for diterpene or phenolic content have been established; research extracts are characterized by total phenolic, flavonoid, and tannin values per gram of dry weight.
**Note**
No supplemental product formulations, capsule doses, or clinically validated dosing regimens exist for Tectona grandis in any reviewed source.
Nutritional Profile
Tectona grandis leaves are not consumed as a food source and have no established nutritional value as a macronutrient or micronutrient contributor to the human diet. The primary bioactive constituents are secondary metabolites: total phenolics at 8.751 ± 0.018 mg GAE/g DW, total flavonoids at 0.359 ± 0.017 mg QE/g DW, and condensed tannins at 0.303 ± 0.000 mg CE/g DW in mature leaf ethanolic extracts. GC-MS analysis of leaf volatile and semi-volatile fractions identifies phytol (a diterpene alcohol with PPAR-α activity), n-decanoic acid (a medium-chain saturated fatty acid with antimicrobial properties), and heptadecenal (a fatty aldehyde). Heartwood sugars include glucose at 43.7–44.6 wt.%, which is relevant to the wood's industrial processing but not to medicinal applications. Bioavailability of the leaf polyphenols and diterpenes has not been characterized in vivo; lipophilicity of the diterpene acids suggests potential for enhanced absorption with fatty meal co-administration, but this remains untested.
How It Works
Mechanism of Action
The primary mechanistic axis of Tectona grandis leaf bioactivity centers on competitive inhibition of 5α-reductase, the enzyme responsible for converting testosterone to dihydrotestosterone (DHT); the diterpenes (+)-Eperua-8,13-dien-15-oic acid and (+)-Eperua-7,13-dien-15-oic acid are the principal inhibitors with IC₅₀ values of approximately 14.2 and 14.7 μM, respectively, positioning them comparably to phytochemical 5α-reductase inhibitors already in dermatological research. Anti-inflammatory effects are mediated through suppression of the NF-κB-dependent inflammatory cascade: the ethanolic extract reduces LPS-induced nitric oxide synthesis (IC₅₀ 12.10 μg/mL), likely by downregulating inducible nitric oxide synthase (iNOS), and independently curtails IL-1β and IL-6 secretion in RAW 264.7 macrophages, indicating inhibition at the level of cytokine transcription or post-translational processing. The antioxidant mechanism involves direct radical scavenging by polyphenols—particularly quercetin and gallic acid—which donate hydrogen atoms to neutralize reactive oxygen species, and indirect protection through chelation of redox-active metal ions by condensed tannins. Phytol, a diterpene alcohol identified by GC-MS, may contribute through activation of peroxisome proliferator-activated receptor-alpha (PPAR-α), modulating lipid metabolism and reinforcing cytoprotective gene expression.
Clinical Evidence
No human clinical trials evaluating Tectona grandis leaf extracts for any indication have been published in the accessible literature. All quantified outcomes originate from in vitro systems: the most clinically relevant findings are 5α-reductase inhibition (extract IC₅₀ 9.57 μg/mL) and IL-6 suppression (IC₅₀ 6.554 μg/mL) in cell-based assays, which provide proof-of-concept but cannot be directly converted to human dosing guidance. The absence of pharmacokinetic data—including oral bioavailability, first-pass metabolism of the active diterpenes, and tissue distribution—represents a critical gap that prevents clinical translation. Confidence in the reported in vitro results is moderate for assay validity but very low for predicting human therapeutic outcomes; the ingredient should be classified as a research-stage botanical pending in vivo confirmation.
Safety & Interactions
In vitro cytotoxicity assessments indicate a favorable safety margin: compound (+)-Eperua-7,13-dien-15-oic acid maintains greater than 80% cell viability in tested cell lines at concentrations up to 100 μg/mL, while the crude extract and compound 1 are non-toxic up to 50 μg/mL under the same conditions. Heavy metal analysis of ethanolic leaf extracts confirms cadmium (0.001–0.004 mg/kg), arsenic (0.012–0.018 mg/kg), and undetectable lead levels, all within internationally recognized safety thresholds, reducing concerns about contaminant-related toxicity. No human side effects, drug-drug interactions, or contraindications have been formally studied or reported in the available literature; however, given the 5α-reductase inhibitory activity, theoretical caution is warranted in individuals using finasteride, dutasteride, or hormonal therapies where additive androgenic pathway modulation may be clinically significant. Use during pregnancy and lactation cannot be assessed due to the complete absence of relevant safety data, and avoidance is the prudent recommendation until in vivo reproductive toxicology studies are conducted.
Synergy Stack
Hermetica Formulation Heuristic
Also Known As
Tectona grandis L.f.TeakSagwan (India)Mai Sak (Thailand)Jati (Indonesia/Java)
Frequently Asked Questions
Can teak leaf extract block DHT and help with hair loss?
In vitro studies show that ethanolic Tectona grandis leaf extract inhibits the enzyme 5α-reductase—which converts testosterone to hair-follicle-damaging DHT—with an IC₅₀ of 9.57 ± 0.09 μg/mL. The isolated diterpenes (+)-Eperua-8,13-dien-15-oic acid and (+)-Eperua-7,13-dien-15-oic acid are the active compounds, with IC₅₀ values of approximately 14.2 and 14.7 μM respectively. However, no human clinical trials have confirmed these effects in living subjects, so teak leaf cannot currently be recommended as a proven hair loss treatment.
What are the main bioactive compounds in Tectona grandis leaves?
The primary characterized bioactives are two diterpene acids—(+)-Eperua-8,13-dien-15-oic acid and (+)-Eperua-7,13-dien-15-oic acid—which account for the 5α-reductase inhibitory and anti-inflammatory activities measured in pharmacological assays. Additionally, mature leaves contain significant polyphenols: total phenolics at 8.751 mg GAE/g dry weight, flavonoids at 0.359 mg QE/g, and condensed tannins at 0.303 mg CE/g, along with GC-MS-detected phytol, n-decanoic acid, and heptadecenal. The heartwood and sapwood also contain lariciresinol, tectonoelins A and B, and anthraquinones including tectoquinone.
Is Tectona grandis leaf extract safe to use?
Based on in vitro cytotoxicity data, the extract and its isolated diterpene compounds show no significant toxicity at concentrations up to 50–100 μg/mL in cell-based assays, with cell viability exceeding 80%. Heavy metal contamination in ethanolic leaf extracts is negligible, with cadmium at 0.001–0.004 mg/kg, arsenic at 0.012–0.018 mg/kg, and lead below detection limits. However, the absence of human pharmacokinetic data, in vivo toxicology studies, and any clinical trial safety monitoring means that a full human safety profile cannot be established at this time.
How is teak leaf used in traditional Thai medicine?
In Thai traditional medicine, Tectona grandis leaves are applied topically for wound healing, leveraging the astringent and antimicrobial properties of the tannin and resinous content. The leaves are typically prepared as a poultice or aqueous decoction and applied directly to skin wounds, a practice corroborated by the measured tannin content (0.303 mg CE/g DW) and the antibacterial phytochemicals identified in the leaves. The compound tectoquinone, found in teak heartwood, is also referenced in Thai pharmacopeial traditions as a bioactive marker associated with wound care applications.
Are there clinical trials on Tectona grandis for any health condition?
No human clinical trials evaluating Tectona grandis extracts for any health condition have been published in the accessible scientific literature. All available mechanistic and efficacy data come from in vitro cell-based studies—including LPS-stimulated RAW 264.7 macrophage assays and enzymatic 5α-reductase inhibition assays—and phytochemical characterization research. The ingredient is currently at a preclinical research stage, and any therapeutic application in humans would require formal pharmacokinetic studies, in vivo animal trials, and randomized controlled human trials before evidence-based recommendations could be made.
How do teak leaf diterpenes compare to pharmaceutical 5α-reductase inhibitors like finasteride?
Teak leaf diterpenes (+)-Eperua-8,13-dien-15-oic acid and (+)-Eperua-7,13-dien-15-oic acid demonstrate in vitro 5α-reductase inhibition with IC₅₀ values in the low micromolar range (14.19–14.65 μM), which is substantially weaker than finasteride's sub-nanomolar potency (IC₅₀ ~0.1 nM). While teak leaf offers a botanical alternative with potentially fewer side effects, its inhibitory potency is approximately 100–1000-fold lower than prescription medications, meaning efficacy in humans remains unproven and likely more modest if present.
What is the recommended dosage of teak leaf extract for hair loss or DHT-related conditions?
No established clinical dosage for teak leaf extract exists, as human trials evaluating efficacy and optimal dosing have not been completed. Traditional Thai medicine uses teak leaves in various preparations (teas, decoctions), but supplement formulations vary widely in concentration and potency. Without human pharmacokinetic data or controlled dose-response studies, recommending a specific amount would be speculative and should only follow manufacturer guidelines or practitioner advice based on available products.
Does teak leaf extract have bioavailability limitations that might affect its 5α-reductase inhibitory activity in the body?
The in vitro potency of teak leaf diterpenes does not necessarily translate to systemic bioavailability or tissue-specific DHT-inhibiting effects in humans, as absorption, metabolism, and distribution of these diterpenes are largely unstudied. Lipophilic compounds like diterpenes often face poor oral bioavailability and rapid hepatic metabolism, which could substantially reduce their effective concentration at target tissues compared to the in vitro IC₅₀ values observed in test tubes. Pharmacokinetic studies in animals or humans would be necessary to determine whether teak leaf supplementation achieves sufficient circulating or scalp concentrations to inhibit 5α-reductase meaningfully.
Explore the Full Encyclopedia
7,400+ ingredients researched, verified, and formulated for optimal synergy.
Browse IngredientsThese statements have not been evaluated by the Food and Drug Administration. This content is for informational purposes only and is not intended to diagnose, treat, cure, or prevent any disease.
hermetica-encyclopedia-canary-zzqv9k4w teak-leaf-tectona-grandis-lf curated by Hermetica Superfoods at ingredients.hermeticasuperfoods.com and licensed CC BY-NC-SA 4.0 (non-commercial share-alike, attribution required)
