Multiple Mycotoxin Contamination in Medicinal Plants Frequently Sold in the Free State Province, South Africa Detected Using UPLC-ESI-MS/MS

Abstract

Medicinal plants are important in the South African traditional healthcare system, the growth in the consumption has led to increase in trade through muthi shops and street vendors. Medicinal plants are prone to contamination with fungi and their mycotoxins. The study investigated multiple mycotoxin contamination using Ultra High Pressure Liquid Chromatography–Tandem Mass Spectrometry (UPLC-ESI-MS/MS) for the simultaneous detection of Aflatoxin B1 (AFB1), Deoxynivalenol (DON), Fumonisins (FB1, FB2, FB3), Nivalenol (NIV), Ochratoxin A (OTA) and Zearalenone (ZEN) in frequently sold medicinal plants. Medicinal plant samples (n = 34) were purchased and analyzed for the presence of eight mycotoxins. DON and NIV were not detected in all samples analyzed. Ten out of thirty-four samples tested positive for mycotoxins —AFB1 (10.0%); OTA (10.0%); FB1 (30.0%); FB2 (50.0%); FB3 (20.0%); and ZEN (30.0%). Mean concentration levels ranged from AFB1 (15 µg/kg), OTA (4 µg/kg), FB1 (7–12 µg/kg), FB2 (1–18 µg/kg), FB3 (1–15 µg/kg) and ZEN (7–183 µg/kg). Multiple mycotoxin contamination was observed in 30% of the positive samples with fumonisins. The concentration of AFB1 reported in this study is above the permissible limit for AFB1 (5 µg/kg). Fumonisin concentration did not exceed the limits set for raw maize grain (4000 µg/kg of FB1 and FB2). ZEN and OTA are not regulated in South Africa. The findings indicate the prevalence of mycotoxin contamination in frequently traded medicinal plants that poses a health risk to consumers. There is therefore a need for routine monitoring of multiple mycotoxin contamination, human exposure assessments using biomarker analysis and establishment of regulations and standards.

Quantitative Analysis of Fungal Contamination of Different Herbal Medicines in China

“…Herbal medicines are widely used for the prevention and treatment of various diseases, such as psychological [1], gynecological [2], gastrointestinal [3], cardiovascular [4], and respiratory diseases [5]. Herbal medicines are highly effective at regulating and repairing Toxins 2024, 16, 229. https://doi.org/10.3390/toxins16050229 https://www.mdpi.com/journal/toxins the immune system during COVID-19 infection [6,7]. Medicinal herbs have been used as dietary supplements for centuries, and more than 80% of the world's population uses herbs as a primary medical resource [8].…”

“…A total of 30% and 26.7% of the 10 common herbs in Pakistan were contaminated with AFs and OTAs, respectively, with 70% of the samples containing toxin levels exceeding the permissible limits [15]. Of the 34 herbs commonly available in the South African market, 10 were contaminated with mycotoxins to varying degrees, with AFBs, FBs, OTA, and ZEN detected [16]. A total of 42% of the 140 herbal teas sold in Latvia were contaminated with 1-16 mycotoxins, of which AFBs were detected in 32% of the samples, and high contents of DON were detected in 63% of the samples [17].…”

Fungal diversity and contamination of some selected medicinal plants in South Africa

“…Other factors include improper handling and porr storage conditions [32,33]. Numerous studies have documented the susceptibility of medicinal plants to fungal and mycotoxin contamination [34][35][36][37][38][39][40]. The growing usage and…”