Trial reportBMC complementary and alternative medicine2019
The fallacy of enzymatic hydrolysis for the determination of bioactive curcumin in plasma samples as an indication of bioavailability: a comparative study.
Trial report in BMC complementary and alternative medicine, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04103788 (Evaluation of Increased Absorption of a Curcumin Emulsion), which is not on this map. Cited by 14 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Evaluation of Increased Absorption of a Curcumin Emulsion (CurQ+) in Healthy Volunteers Either Following Enzymatic Hydrolysis Pre-Treatment or Direct Analysis of Split Serum Samples
Who cites it
14 citing papers in PubMed, 1 synthesis or guideline pooled it, 30 citations in OpenAlex.
- Pooled it
- Probiotics and Curcumin Did Not Alter Low-Dose Streptozotocin-Induced Hyperglycemia and Oxidative Stress in a Rat Model.Food science & nutrition · 2026Article
- Natural Products for Improving Soft Tissue Healing: Mechanisms, Innovations, and Clinical Potential.Pharmaceutics · 2025Review
- Advancements in curcuminoid formulations: An update on bioavailability enhancement strategies curcuminoid bioavailability and formulations.Open life sciences · 2025Review
- Innovative Delivery Systems for Curcumin: Exploring Nanosized and Conventional Formulations.Pharmaceutics · 2024Review
- Curcumin and Resveratrol: Nutraceuticals with so Much Potential for Pseudoachondroplasia and Other ER-Stress Conditions.Biomolecules · 2024Review
- Role of the Dietary Phytochemical Curcumin in Targeting Cancer Cell Signalling Pathways.Plants (Basel, Switzerland) · 2023Review
- Article
- Polar Phenol Detection in Plasma and Serum: Insights on Sample Pre-Treatment for LC/MS Analysis and Application on the Serum of Corinthian Currant-Fed Rats.Biomolecules · 2022Article
- Effect of curcumin supplementation on exercise-induced muscle damage: a narrative review.European journal of nutrition · 2022Review
- Biomedical Applications and Bioavailability of Curcumin-An Updated Overview.Pharmaceutics · 2021Review
- Improving Curcumin Bioavailability: Current Strategies and Future Perspectives.Pharmaceutics · 2021Review
- Tetrahydrocurcumin Ameliorates Skin Inflammation by Modulating Autophagy in High-Fat Diet-Induced Obese Mice.BioMed research international · 2021Article
- Highly Bioavailable Forms of Curcumin and Promising Avenues for Curcumin-Based Research and Application: A Review.Molecules (Basel, Switzerland) · 2020Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 4 institutions in 1 country.
Funding
Abstract
backgroundNumerous health benefits have been demonstrated for curcumin which is extracted from turmeric (Curcuma longa L). However, due to its poor absorption in the free form in the gastrointestinal tract and rapid biotransformation, various formulations have been developed to enhance its bioavailability. Previous studies indicate that the free form of curcumin is more bioactive than its conjugated counterparts in target tissues. Most curcumin pharmacokinetics studies in humans designed to assess its absorption and bioavailability have measured and reported total (free plus conjugated) curcumin, but not free, bioactive curcumin in the plasma because enzymatic hydrolysis was employed prior to its extraction and analysis. Therefore, the bioavailability of free curcumin cannot be determined.
methodsEight human subjects (4 male, 4 female) consumed a single dose of 400 mg curcumin in an enhanced absorption formulation, and blood samples were collected over 6 h. Plasma was treated either with or without glucuronidase/sulfatase prior to extraction. Curcumin and its major metabolites were analyzed using HPLC-tandem mass spectrometry. In addition, the literature was searched for pharmacokinetic studies involving curcumin using PubMed and Google Scholar, and the reported bioavailability data were compared based on whether hydrolysis of plasma samples was used prior to sample analysis.
resultsHydrolysis of blood plasma samples prior to extraction and reporting the results as "curcumin" obscures the amount of free, bioactive curcumin and total curcuminoids as compared to non-hydrolyzed samples. As a consequence, the data and biological effects reported by most pharmacokinetic studies are not a clear indication of enhanced plasma levels of free bioactive curcumin due to product formulations, leading to a misrepresentation of the results of the studies and the products when enzymatic hydrolysis is employed.
conclusionsWhen enzymatic hydrolysis is employed as is the case with most studies involving curcumin products, the amount of free bioactive curcumin is unknown and cannot be determined. Therefore, extreme caution is warranted in interpreting published analytical results from biological samples involving ingestion of curcumin-containing products.
trial registrationClinicalTrails.gov, trial identifying number NCT04103788 , September 24, 2019. Retrospectively registered.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.