Volume 30, April 2015, Pages 54–58
Special Section: Iron and Obesity
Toxicology
Determination of toxic metals by ICP-MS in Asiatic and European medicinal plants and dietary supplements
Abstract
The potentially toxic metals content was determined in selected plants, used in Traditional Chinese Medicine (Angelica sinensis, Bacopa monnieri, Bupleurum sinensis, Curcuma longa, Cola accuminata, Emblica officinalis, Garcinia cambogia, Mucuna pruriens, Ocimum sanctum, Panax ginseng, Pueraria lobata, Salvia miltiorrhiza, Schisandra sinensis, Scutellaria baicalensis, Siraitia grosvenorii, Terminalia arjuna and Terminalia chebula), and some European herbs (Echinacea purpurea, Hypericum perforatum, Vitis vinifera). Samples were mineralized in a closed microwave system using HNO3
and the concentrations of Cd, Pb, Al, As, Ba, Ni and Sb were determined
by ICP-MS method. Some relevant aspects of potential toxicity of
metallic elements and their compounds were also discussed. Results of
metal content analysis in dietary supplements available on Polish
market, containing studied plants, are presented as well. The results
were analyzed by principal component analysis (PCA) and cluster
analysis.
Keywords
- Toxic metals;
- Asiatic herbs;
- Dietary supplements;
- ICP-MS
Introduction
Pollution
of food and dietary supplements by different metals may be caused by
contaminated environment, fertilizers used in agriculture, various
anthropogenic pollutants or inappropriate storage techniques. The level
of toxic elements in plants can be affected by the geochemical
parameters of soil, pollution of water, air and by the ability of plants
to selectively accumulate some elements. Furthermore, metals may also
be related to the geographical origin, harvesting or collection of these
plant materials. Some metals (such as Cr, Mn, Mo, Zn, Fe, Co, Cu, Al,
Ni) are essentials plant nutrients, however, they are phytotoxic at
higher concentrations.
Long
term consumption of Cd, Pb, Hg, Ba, Sb, As is hazardous for human
health and life. The hazardous effect of metals on animals and human
beings decreases approximately in the following order:
Hg > Cu > Zn > Ni > Pb > Cd > Cr > Sn > Fe > Mn > Al
[1].
Hence, with increasing industrialization and environmental pollution,
it is necessary to monitor the content of some toxic elements in
medicinal herbs.
In the
recent years, consumption of healthy food, nutraceuticals and herbal
dietary supplements in Europe has increased significantly. These
products are produced from plants or other natural sources. It is easier
for people to believe that phytotherapy, medicinal herbs and plants are
not aggressive and do not have side effects on health. However, the Act
or Regulation of Food Safety do not define the quality requirements and
control methods of dietary supplements. Producers are only obliged to
carry out the analysis of microbiological purity and contamination by
the most popular hazardous metals (Pb and Cd) in raw plant extracts. In
consequence, herbal medicines and dietary supplements are marketed
without certificates confirming their quality and content of toxic
metals. Change in the regulation on medicinal plants and dietary
supplements contamination by toxic metals could, therefore, help the
quality assessment of these products and can reduce health risk by
potentially contaminated supplements. Thus, it is necessary to monitor
the content of potentially toxic elements.
In
addition to different metals, the plant material can be contaminated
with pesticides, microbial contaminants and other chemical toxins. They
can also be contaminated during chemical treatment or storage [2] and [3].
The
main aim of this work is evaluation of selected metals content in raw
plant material and dietary supplements. The development of methods for
detecting toxic, hazardous metals in traditional Chinese medicines and
the investigation of the level of contamination of traditional Chinese
medicines is our goal.
In
this study, the content of toxic metals (Pb, Cd, As, Al, Ni, Ba, Sb) in
Asiatic medicinal plants, using in Ayurveda or Traditional Chinese
Medicine (such as Angelica sinensis, Bacopa monnieri, Bupleurum sinensis, Curcuma longa, Cola accuminata, Emblica officinalis, Garcinia cambogia, Mucuna pruriens, Ocimum sanctum, Panax ginseng, Pueraria lobata, Salvia miltiorrhiza, Schisandra sinensis, Scutellaria baicalensis, Siraitia grosvenorii, Terminalia arjuna and Terminalia chebula), and some European herbs (Echinacea purpurea, Hypericum perforatum, Vitis vinifera)
were determined by inductively coupled plasma with mass spectrometry
(ICP-MS). The content of toxic metals in plants was compared with
dietary supplements available on the Polish market, which contain
studied plants and herbs from Asia and Europe.
Materials and methods
Materials
Angelica sinensis (AS), Bacopa monnieri (BM), Bupleurum sinensis (BS), Cola accuminata (CA), Curcuma longa (CL), Garcinia cambogia (GC), Mucuna pruriens (MP), Ocimum sanctum (OS), Panax ginseng (PG), Pueraria lobata (PL), Scutellaria baicalensis (SB), Siraitia grosvenorii (SG), Salvia miltiorrhiza (SM), Schisandra sinensis (SS), Terminalia arjuna (TA), Terminalia chebula (TCh), were purchased from STANLAB (Lublin, Poland). Curcuma longa
(CL) was purchased from two different producers so we coded CL: CL-H
and CL-P. Plant materials and herbs, such as: Emblica officinalis (Amla)
and Vitis vinifera (VV) from Biofaktor (Gorzów Wlkp., Poland), Echinacea purpurea (EP) from FLOS (Mokrsko, Poland), while Hypericum perforatum
(HP) from Herbapol (Lublin, Poland). Dietary supplements (coded as
DS-AMLA, DS-AS1, DS-AS2, DS-BM, DS-CA, DS-CL, DS-GC1, DS-GC2, DS-PG1,
DS-PG2, DS-PL1, DS-PL2, DS-PL3, DS-EP1, DS-EP2, DS-VV1, DS-VV2, and
mixed DS-AMLA,VV; DS-PG,VV) were bought in local pharmacy. Ultrapure
nitric acid (65%) was supplied from POCH (Poland). Multi-elemental
mixture of metal standards was purchased from Agilent Technologies,
Japan. Deionized water (conductivity ≤ 0.5 μS) was used for analysis
