Terminalia chebula: Powerful Antioxidant Benefits?

Key Findings

This review identified Terminalia chebula as one of the top-performing Thai FDA-approved medicinal plants for antioxidant activity. Among 12 standardized plant extracts analyzed, T. chebula demonstrated the strongest free radical scavenging capacity in DPPH assays (IC₅₀ = 12.3 ± 0.8 μg/mL) and significant ferric reducing antioxidant power (FRAP value: 1,842 ± 45 μmol TE/g). The study concluded that T. chebula’s high polyphenol content (particularly chebulinic acid) correlates with its neuroprotective potential against oxidative stress, positioning it as a candidate for functional food development targeting neurodegenerative diseases.

Study Design

This was a systematic literature review (not primary research) analyzing existing studies on Thai FDA-approved medicinal plants for dietary supplements. The methodology included:
- Source evaluation: 42 peer-reviewed studies (2015–2024) on 12 plants meeting Thai FDA safety standards.
- Standardization: Extracts were standardized to marker compounds (e.g., T. chebula to 30% chebulinic acid).
- In vitro testing: Antioxidant assays (DPPH, FRAP, ORAC) performed per AOAC protocols.
- No human/animal samples: Entirely laboratory-based analysis of published data; no new clinical samples or duration parameters.

Dosage & Administration

No dosage tested in this review. The analysis compiled data from prior studies where T. chebula extracts were administered in vitro at concentrations of 5–100 μg/mL. Human-relevant doses were not established, as the review focused on mechanistic antioxidant potential rather than clinical dosing.

Results & Efficacy

T. chebula outperformed all other plants in key metrics:
- DPPH scavenging: IC₅₀ 12.3 ± 0.8 μg/mL (vs. gallic acid standard IC₅₀ 8.1 ± 0.3 μg/mL; p < 0.001).
- FRAP: 1,842 ± 45 μmol TE/g (2.1× higher than Curcuma longa; p = 0.002).
- ORAC: 3,210 ± 78 μmol TE/g.
Statistical significance was confirmed via ANOVA with Tukey’s post-hoc test (p < 0.01 for all comparisons). Polyphenol content strongly correlated with activity (R² = 0.93).

Limitations

1. No clinical data: Purely in vitro evidence; no human trials assessed.
2. Extraction variability: Differences in solvent methods across source studies may affect comparability.
3. Bioavailability unaddressed: Did not evaluate absorption or metabolism of active compounds.
4. Selection bias: Focused only on Thai FDA-approved plants, excluding globally studied alternatives.
   Future research should prioritize in vivo neuroprotection models and dose-response human studies.

Clinical Relevance

While promising, these findings indicate T. chebula’s potential as a neuroprotective ingredient, not proven clinical efficacy. Supplement users should note:
- Current evidence supports antioxidant mechanisms but not direct disease prevention in humans.
- Products should specify standardized chebulinic acid content (≥30%) for consistent effects.
- Consult healthcare providers before use, especially with anticoagulants (theoretical interaction risk from polyphenols). This review provides a scientific basis for further development but does not justify therapeutic claims.