Naringin is a Major and Selective Clinical Inhibitor of Organic Anion-Transporting Polypeptide 1A2 (OATP1A2) in Grapefruit Juice
Bibliographic record
Abstract
We showed previously that grapefruit and orange juices inhibited human enteric organic anion-transporting polypeptide (OATP)1A2 in vitro and lowered oral fexofenadine bioavailability clinically. Inhibition of OATP1A2 transport by flavonoids in grapefruit (naringin) and orange (hesperidin) was conducted in vitro. Two randomized, crossover, pharmacokinetic studies were performed clinically. In one study, 120 mg of fexofenadine was ingested with 300 ml grapefruit juice, an aqueous solution of naringin at the same juice concentration (1,200 microM), or water. In the other study, fexofenadine was administered with grapefruit juice, with or 2 h before aqueous suspension of the particulate fraction of juice containing known clinical inhibitors of enteric CYP3A4, but relatively low naringin concentration (34 microM), or with water. Naringin and hesperidin's half-maximal inhibitions were 3.6 and 2.7 microM, respectively. Fexofenadine area under the plasma drug concentration-time curves (AUCs) with grapefruit juice and naringin solution were 55% (P<0.001) and 75% (P<0.05) of that with water, respectively. Fexofenadine AUCs with grapefruit juice and particulate fractions were 57% (P<0.001), 96% (not significant (NS)), and 97% (NS) of that with water, respectively. Individuals tested in both studies (n=9 of 12) had highly reproducible fexofenadine AUC with water (r(2)=0.85, P<0.001) and extent of reduction of it with grapefruit juice (r(2)=0.72, P<0.01). Naringin most probably directly inhibited enteric OATP1A2 to decrease oral fexofenadine bioavailability. Inactivation of enteric CYP3A4 was probably not involved. Naringin appears to have sufficient safety, specificity, and sensitivity to be a clinical OATP1A2 inhibitor probe. Inherent OATP1A2 activity may be influenced by genetic factors. This appears to be the first report of a single dietary constituent clinically modulating drug transport.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| 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".