Contamination of Aflatoxins in Herbal Medicinal Products in Thailand

Abstract

Twenty-eight herbal medicinal products from Thailand were investigated for aflatoxin (AF) contaminations by employing a specific HPLC assay for the determination of AFB1, B2, G1 and G2. The samples were extracted with 80% (v/v) methanol in water before further cleaned up with an immunoaffinity column and followed by the detection of AFs by using an electrochemically post-column derivatization with iodine and fluorescence detector. The extraction procedure was optimized in order to obtain the best recovery. The method was successfully carried out with all the herbal products diversified as to compositions and dosage forms. The results revealed that five (18%) of herbal samples were contaminated with detectable amount of the total AFs ranging from 1.7 to 14.3 ng/g. The association between particular herbal/plant and the AF contaminated could not be determined due to the low frequency of positive samples. The contaminated products were those in tablet (4) and capsule (1) dosage forms. It was possible that the original fungal infection of these products may have been derived from either the crude herbal or other ingredients making these preparations, such as starch. In conclusion, none of the AF contaminated level found was above the current legislative level permissible in Thailand (20 ng/g). A word of caution, however, exporting some high AF-contaminated herbal products to countries where more stringent permissable level of aflatoxins exist could result in trade Barriers.

Occurrence of toxigenic fungi in herbal drugs

“…The results showed that 54.9% of the samples exceeded the limit determined by the US Pharmacopoeia (26) and these results are in agreement with those of previous studies (16)(17)(18)21,25 4 cfu/g) were the most contaminated samples. According to plant part used, the highest counts of fungal isolates were observed in leaves and aerial parts (50.0%) followed by flowers (16.0%), rhizomes and roots (12.0%), barks (12.0%) and seeds (10.0%).…”

“…The premise that traditional use of these medicinal products for generations establishes their safety does not necessarily attest to their safety and efficacy. Indeed, the adverse effects of long-term herbal use, adulteration with toxic compounds and contamination by pathogenic microbials or natural toxins like mycotoxins have been reported for herbal products and medicinal plants (1,2,(7)(8)(9)(10)(11)13,(16)(17)(18)(19)(20)(21)(22)25).…”

“…Practices used in harvesting, handling, storage, production and distribution make medicinal plants subject to contamination by various fungi, which may be responsible for spoilage and production of mycotoxins (1,11,13,25). Fungi of the genera Aspergillus and Penicillium, largely distributed in the Brazilian ecosystem, are known to contain strains that produce mycotoxins.…”

Determinação de aflatoxina B1 em pimenta (Piper nigrum L.) e orégano (Origanum vulgare L.) por cromatografia em camada delgada e densitometria

“…Devido a sua especificidade, o emprego de coluna de imunoafinidade atualmente está bem difundido em diferentes tipos de alimentos, como café, cerveja, leite, queijo, suco de maçã, iogurte e matrizes complexas como salsa e plantas medicinais. [20][21][22][23][24][25][26][27][28][29][30][31] O objetivo desse trabalho foi avaliar o grau de contaminação com aflatoxina B 1 em amostras de pimenta (Piper nigrum L.) e orégano (Origanum vulgare L.) comercializadas no estado de Minas Gerais. Inicialmente, foram avaliados alguns parâmetros de um método analítico, utilizando extração com metanol-água, purificação em coluna de imunoafinidade e detecção e quantificação da aflatoxina B 1 por cromatografia em camada delgada/densitometria.…”

Aflatoxin Measurement and Analysis

“…However, in order to improve detection limits of AFB 1 and AFG 1 , a tedious pre-or postcolumn derivatization must be done in conventional HPLC methods Tassaneeyakul et al, 2004). These problems have been successfully solved in the present study by introducing HPLC-MS method.…”