Analysis of the hypericin and pseudohypericin content of commercially available St John's Wort preparations.
Bibliographic record
Abstract
CONTEXT: The use of herbal medications and supplements has been growing worldwide with over four billion dollars a year spent on alternative medicines in the United States. St John's wort herbal preparations are generally standardized to "total hypericins" as a means of illustrating a degree of quality control to the consumer. This standardization has been based on a nonspecific method that overestimates and sums the two major naphthodianthrone compounds (hypericin and pseudohypericin) that are found in these products. OBJECTIVE: To use a more specific and sensitive method to accurately determine the total hypericin content (sum of hypericin and pseudohypericin) in commercially available St John's wort herbal preparations. DESIGN: The current standard method for determining the naphthodianthrone content is a spectrophotometric method specified in the United States Pharmacopeia. Compounds other than hypericin and pseudohypericin can contribute falsely to the naphthodianthrone concentration, reducing this methods specificity. SETTING: Fifty-four commercially available St John's wort products were purchased in Canada and the United States. MAIN OUTCOME MEASURES: A specific and sensitive liquid chromatographic method with fluorescent detection was used to specifically quantify the hypericin and pseudohypericin content in commercially purchased St John's wort products. RESULTS: Analysis revealed large variations in total naphthodianthrone content, with the percentage of label claim varying from 0% to 108.62% for capsules, and from 31.34% to 80.18% for tablets. The content of tinctures varied from zero to 118.58 microg/ml. Only two products were observed to have a total naphthodianthrone concentrations within 10% of their label claim. CONCLUSIONS: When the active or marker compounds in an herbal or alternative medicine have been identified, standardization is an important step to ensure consistency from batch to batch. However, consistency is not apparent between brands and most products have inaccurate label claims. On average, most labels overestimate the hypericin and pseudohypericin content by a factor of almost two.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".