Phenylalanine
| 證據等級: L5 | 預測適應症: 2 個 |
目錄
Phenylalanine: From Essential Amino Acid Supplementation to Sclerosing Cholangitis
One-Sentence Summary
Phenylalanine is an essential amino acid with no registered therapeutic indication and no SAHPRA market presence in South Africa. The TxGNN model predicts a possible association with Sclerosing Cholangitis, but on review the supporting literature (4 publications, 0 clinical trials) does not describe phenylalanine as a treatment for this condition — the signal appears to be a knowledge-graph artefact rather than a genuine pharmacological hypothesis.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Not established — phenylalanine is an essential amino acid with no registered therapeutic indication in South Africa |
| Predicted New Indication | Sclerosing Cholangitis |
| TxGNN Prediction Score | 99.43% |
| Evidence Level | L5 |
| South Africa Market Status | Not marketed |
| Number of SAHPRA Registrations | 0 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data for phenylalanine in this context is not available, and no combination/drug class association is documented in the evidence pack.
More importantly, a review of the supporting literature does not establish a credible mechanistic link. None of the four retrieved publications studies phenylalanine as a treatment for sclerosing cholangitis: one examines plasma tyrosine (not phenylalanine) levels and fatigue in primary biliary cirrhosis/primary sclerosing cholangitis patients as an observational biomarker; one is a serum metabolomic profiling study in cholangiocarcinoma; and two describe fMLP (N-formyl-methionyl-leucyl-phenylalanine), a synthetic neutrophil-chemotactic tripeptide used to induce bile-duct inflammation in rat models — phenylalanine here is merely one amino-acid residue within an unrelated synthetic peptide, not free phenylalanine acting pharmacologically.
Given this, the high TxGNN score (99.43%) most likely reflects graph-embedding co-occurrence (e.g., shared terms such as “phenylalanine,” “tyrosine,” and “biliary/cholangitis” across unrelated studies) rather than a genuine biological hypothesis. This prediction should be treated as a data-driven signal requiring independent pharmacological justification, not as a validated mechanistic rationale.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 15790420 | 2005 | Cohort/Observational | BMC Gastroenterology | Examined plasma tyrosine (not phenylalanine) concentration and its relation to fatigue in primary biliary cirrhosis and primary sclerosing cholangitis; not an interventional or phenylalanine-treatment study |
| 32025163 | 2020 | Cohort/Metabolomics | Journal of Clinical and Experimental Hepatology | Serum metabolomic profiling in cholangiocarcinoma vs. benign hepatobiliary disease for biomarker discovery; not a treatment study |
| 8000512 | 1994 | Animal model | Journal of Gastroenterology | Rat model of small-duct cholangitis induced by the synthetic chemotactic peptide fMLT (contains a phenylalanine residue); mechanistically unrelated to free phenylalanine pharmacology |
| 2103382 | 1990 | Basic/Radioimmunoassay method | Journal of Gastroenterology and Hepatology | Describes enterohepatic circulation of bacterial chemotactic peptides (F-met-oligopeptides) in humans; an assay-methodology paper, not a phenylalanine treatment study |
South Africa Market Information
No SAHPRA-registered products were found for phenylalanine. The drug is currently not marketed in South Africa (0 registrations).
Safety Considerations
Please refer to the SAHPRA-approved Professional Information (PI) for safety information. Report adverse drug reactions to SAHPRA.
Note: A Professional Information warnings/contraindications review is flagged as a Blocking data gap — this must be resolved before any safety pre-assessment can proceed.
Conclusion and Next Steps
Decision: Hold
Rationale: The TxGNN score is high, but none of the retrieved literature supports a real pharmacological link between phenylalanine and sclerosing cholangitis, no clinical trials exist for this candidate, and a Blocking data gap (PI warnings/contraindications) prevents even an initial safety assessment.
To proceed, the following is needed:
- PI warnings and contraindications data (Blocking gap — DG001)
- Mechanism of action (MOA) data for phenylalanine (High-priority gap — DG002)
- Independent pharmacological or preclinical evidence directly linking phenylalanine (not tyrosine or unrelated synthetic peptides) to biliary/cholangitis pathways
- Confirmation of any future SAHPRA registration status, since the drug is currently unmarketed in South Africa
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.