Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. What was studied?
This original research article investigated the bioaccessibility and health risk of heavy metals, with a detailed analysis of arsenic speciation, in Cordyceps sinensis, a highly valued traditional Chinese medicine. The study focused on quantifying the levels of copper (Cu), lead (Pb), arsenic (As), cadmium (Cd), and mercury (Hg) in different parts of wild C. sinensis (whole, stroma, and caterpillar body) collected from Qinghai Province, China. Using in vitro gastrointestinal digestion, the authors assessed how much of each heavy metal could be potentially absorbed by the human body, which is essential for accurate risk assessment. Advanced analytical methods, specifically HPLC–ICP-MS, were employed to determine the chemical forms of arsenic, distinguishing between the more toxic inorganic species and the less harmful organic forms. The study also calculated dietary exposures and bioaccessibility-corrected target hazard quotients (BTHQ) to estimate the health risks associated with consumption, considering realistic human intake scenarios relevant to both research and regulatory contexts in heavy metal certification programs.
Who was studied?
The subjects of this study were three 30 g batches of wild-grown Cordyceps sinensis sourced from Qinghai Province, China. Each batch was further divided into the whole organism, the stroma (fungal part), and the caterpillar body (host larva). No human participants or animal models were involved; instead, the focus was on the chemical and toxicological analysis of these natural product samples. The findings are thus directly applicable to industry stakeholders, regulatory agencies, and certification bodies concerned with the safety and compliance of C. sinensis in the marketplace, particularly regarding heavy metal contamination.
Most important findings
| Critical Point | Details |
|---|---|
| Heavy Metal Distribution | Cu, Pb, Cd, and Hg were higher in the stroma, whereas As was predominantly in the caterpillar body. Average As content was notably high in C. sinensis, ranging from 9 to 14 mg/kg. |
| Bioaccessibility | None of the five heavy metals could be fully absorbed by human digestion; mean bioaccessibility ranged from 7.46% for Hg to 87.07% for Cd, with As at around 64.46%. This indicates that total content overestimates actual exposure risk. |
| Arsenic Speciation | Strongly toxic inorganic arsenic (As(III) and As(V)) accounted for only 8.69% of total As in nitric acid extracts and 2.33% in simulated gastrointestinal extracts. The majority of arsenic remained as unidentified, likely less toxic, species. |
| Health Risk Assessment | Dietary exposures for all metals were far below international safety limits. The BTHQ for arsenic was 0.5334, the highest among all elements, but still under the threshold of 1.0, indicating no significant health risk under recommended usage. |
| Regulatory Implications | Findings suggest that current heavy metal standards, especially for arsenic in C. sinensis, may be excessively strict, as actual bioaccessible and toxic fractions are much lower than total content would suggest. |
Key implications
For heavy metal certification programs, this study demonstrates the necessity of using bioaccessibility and speciation, not total content, for risk assessment. The results indicate C. sinensis poses minimal health risks when consumed as recommended, supporting a potential re-evaluation and relaxation of heavy metal limits, especially for arsenic.
Citation
Zhou L, Wang S, Hao Q, Kang L, Kang C, Yang J, Yang W, Jiang J, Huang LQ, Guo L. Bioaccessibility and risk assessment of heavy metals, and analysis of arsenic speciation in Cordyceps sinensis. Chin Med. 2018;13:40. https://doi.org/10.1186/s13020-018-0196-7
