The study, published in Food Control, analysed 241 samples of herbal medicines and functional foods to test for the presence of ‘high toxicity’ aflatoxins that are produced by certain fungi that grow in humid conditions.
Led by Donghun Lee from Dongguk University-Seoul, the team compared two analytical methods for the detection of secondary metabolites of Aspergillus flavus and Aspergillus parasiticus in a range of herbal medicines and functional foods that contained botanical extracts.
“Aflatoxins occur in grains and herb medicines in humid conditions,” noted the team – who noted that in particular, herbal medicines have been reported as a major source of aflatoxin.
Indeed, previous research in Brazil identified aflatoxin-producing fungi and microorganisms in nearly 43% of botanical herbs.
“Among 241 samples, only Angelica gigas NAKAI extract products (2 products) were detected to have (…) aflatoxin,” wrote the team.
In order to obtain a representative sample of products and aflatoxins from botanical sources, the team surveyed 2,348 participants and directly collected samples of any herbal medicines and functional products they were using. The 241 samples collected were then used to compare two analytical methods to identify the aflatoxins B1, B2, G1 and G2.
“Among 20 types of aflatoxins, 4 types of AFs including B1, B2, G1, and G2 commonly occur in the natural environment," said the team, adding that aflatoxin B1, M1, G1, M2, B2, and G2 have high toxicity “and aflatoxin B1 and G1 have higher biological toxicity.”
Indeed, the International Agency for Research on Cancer (IARC) classified aflatoxin B1 as Group 1 carcinogen (carcinogenic to humans) in 1993, they noted.
Donghun and colleagues compared trifluoroacetic acid and Kobra cell derivatization methods of testing for these aflatoxins – finding that the Kobra method had a higher sensitivity.
“The analytical methods of HPLC–FLD with Kobra cell were compared with the TFA method,” noted the team. “Due to the high sensitivity and wide linearity of the Kobra cell method, it was selected for analyzes of AFs in HFFs and herbal medicines.”
Using the Kobra cell method, the team then found that among the 241 samples, only A. gigas NAKAI extract products (2 products) had levels of aflatoxins. These products were found to contain 7.93 and 5.70 nanograms per gram of the aflatoxin G2.
Source: Food Control
Volume 48, Pages 33–36, doi: 10.1016/j.foodcont.2014.02.007
“Analysis of aflatoxins in herbal medicine and health functional foods”
Authors: Donghun Lee, et al