Saint John’s wort (Hypericum perforatum L.-HP) is well-known for its traditional medicinal use. It is currently licensed in Europe as a medicine or as a THR product, but unregulated products remain accessible through secondary means. A previous study (Booker et al. 2018), looking into the quality of HP products (including THRs and food supplements), highlighted how significantly different their chemical content could be.
The study aimed at continuing the assessment of HP products quality by looking into the variability of the starting material and using the results to pinpoint where regulations can be improved.
A combination of NMR metabolomics and Pharmacopoeia-based HPTLC fingerprinting was used to investigate the chemical profile of 86 Hypericum samples (77 H. perforatum) collected in 14 countries.
Significant variations between species’ chemical fingerprints were found but limited significant differences within samples collected in distinct geographical locations. A previously reported “Chinese Saint John’s wort” fingerprint, featuring a number of anomalies, when compared to the European Pharmacopoeia standard (Booker et al. 2018), has been matched to 100% of the samples coming from China. One of the characteristics has been positively identified as avicularin, which was also found in 50% of the specimens from Spain, but in no other sample. Rutin was not present in 38% of samples. Lower flavonoids concentration was detected in materials of commercial origin and were generally associated with a higher content of woody stems and possibly higher sample age.
This study reinforces the knowledge that unregulated herbal products quality is not reliable and a way to insure safety needs to be found. The importance of appropriately choosing, sourcing and handling materia prima is highlighted, alongside the need for a regulatory system that is informed about the natural variability of the raw material.
References:
Booker et al. Phytomedicine (2018);40:158-164