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Health Risk Assessment of Toxic Metal(loids) Consumed Through Plant-Based Anti-diabetic Therapeutics Collected in the Northern Divisional City of Rajshahi, Bangladesh

Authors:
Nazmul Islam at Daffodil International University
Nazmul Islam
Rasuan Zamir at University of Rajshahi
Rasuan Zamir
Omar Faruque at Jashore University of Science and Technology
Omar Faruque
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Abstract

The present study investigates human health risks upon consumption of herbal medicines in terms of ten toxic metalloids in 20 plant-based anti-diabetic therapeutics. The analysis of metalloids was determined by an atomic absorption spectrometer after microwave-assisted digestion. The computation of hazard quotients (HQ) and hazard indexes (HI) of metalloids leads to the assessment of non-carcinogenic health risks. Carcinogenic risk was assessed based on cancer slope factor (CSF) and chronic daily intake (CDI) values. Comparison with WHO regulatory cut-off points for each metalloid: seven samples for Mn, 12 samples for Hg, three samples for Cu, eight samples for Ni, four samples for Cd, two samples for Pb, one sample for Cr, and eight samples for Zn are unsafe to consume. Non-carcinogenic human health risk is predicted for Mn in seven samples, Fe in one sample, Hg in ten samples, Cu in three samples, Ni in one sample, and Pb in two samples. HI values greater than 1 predict non-carcinogenic health risk in thirteen samples. Incremental lifetime cancer risk (ILCR) remains for As (inorganic) in 12 samples, Cr (+ 6) in one sample, and Pb in no samples. To guarantee consumer safety, the implementation of strict monitoring is suggested.
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Vol.:(0123456789)
Biological Trace Element Research (2025) 203:2149–2158
https://doi.org/10.1007/s12011-024-04338-7
RESEARCH
Health Risk Assessment ofToxic Metal(loids) Consumed Through
Plant‑Based Anti‑diabetic Therapeutics Collected intheNorthern
Divisional City ofRajshahi, Bangladesh
NazmulIslam1· RausanZamir2· OmarFaruque3
Received: 19 May 2024 / Accepted: 5 August 2024 / Published online: 12 August 2024
© The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024
Abstract
The present study investigates human health risks upon consumption of herbal medicines in terms of ten toxic metalloids in
20 plant-based anti-diabetic therapeutics. The analysis of metalloids was determined by an atomic absorption spectrometer
after microwave-assisted digestion. The computation of hazard quotients (HQ) and hazard indexes (HI) of metalloids leads
to the assessment of non-carcinogenic health risks. Carcinogenic risk was assessed based on cancer slope factor (CSF) and
chronic daily intake (CDI) values. Comparison with WHO regulatory cut-off points for each metalloid: seven samples for
Mn, 12 samples for Hg, three samples for Cu, eight samples for Ni, four samples for Cd, two samples for Pb, one sample
for Cr, and eight samples for Zn are unsafe to consume. Non-carcinogenic human health risk is predicted for Mn in seven
samples, Fe in one sample, Hg in ten samples, Cu in three samples, Ni in one sample, and Pb in two samples. HI values
greater than 1 predict non-carcinogenic health risk in thirteen samples. Incremental lifetime cancer risk (ILCR) remains for
As (inorganic) in 12 samples, Cr (+ 6) in one sample, and Pb in no samples. To guarantee consumer safety, the implementa-
tion of strict monitoring is suggested.
Keywords Plant-based anti-diabetic therapeutics· Carcinogenic and non-carcinogenic risks· Hazard quotient· Hazard
index· Incremental lifetime cancer risk
Introduction
Plant-based therapeutics are herbal drugs that are prepared
from different medicinal herbs. Therapeutics are prone
to contamination with metalloids due to their source and
nature. Herbs can be contaminated with metalloids dur-
ing growing, harvesting, and processing. Metalloids are
considered persistent pollutants due to their non-biodeg-
radability in nature [1, 2]. Different natural and anthropo-
genic activities render them available in nature. Continuous
urbanization and industrialization in the developing world
have led to high levels of metalloid contamination in the soil
and surrounding environment [3, 4]. Entry routes for toxic
metalloids in herbs in different stages are believed to be the
following: polluted soils, industrial emissions, transporta-
tion, water used in irrigation, fertilizers and pesticides, and
storage processes [5–7]. The manufacturing of herbs into
finished formulations also contributes to metalloid contami-
nation [8].
Plant-based therapeutics are conventionally used for
the treatment and prevention of different chronic and acute
diseases like diabetes, hypertension, stomach pain, and
headaches [5, 9]. With an increasing aging population and
a change in lifestyle, chronic diseases like diabetes are on
the rise. For the prevention and management of the dis-
ease, along with allopathic drugs, plant-based anti-diabetic
therapeutics are frequently used health resources [10, 11].
* Nazmul Islam
nazmul.acce.26@gmail.com
Rausan Zamir
rsnzamir@gmail.com
Omar Faruque
faruque.nft.just@gmail.com
1 Department ofTextile Engineering, Daffodil International
University, Dhaka, Bangladesh
2 Department ofChemistry, University ofRajshahi, Rajshahi,
Bangladesh
3 Department ofNutrition andFood Technology, Jashore
University ofScience andTechnology, Jashore, Bangladesh
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Traditional and complementary medicine is an important and often underestimated health resource with many applications, especially in the prevention and management of chronic diseases and in meeting the health needs of aging populations [2]. Ethiopia is known for its rich tradition of herbal medicine. Herbs are traditionally used for the treatment and prevention of diseases such as stomach pain, headache, diabetes, hypertension, rheumatism, and many others [3]. There has been an increasing concern over the safety and toxicity of natural herbal formulations available on the market. In general, herbal preparations can be contaminated during growing, harvesting, and processing. Sources of heavy metal contamination in herbal preparations could be linked to water used in irrigation, polluted soils, fertilizers and pesticides, industrial emissions, transportation, and harvesting and storage processes [3,4]. Metals such as zinc, iron, manganese, and copper are essential elements since they play an important role in biological systems and only become harmful at high concentrations, whereas mercury, lead, arsenic, chromium, and cadmium are nonessential elements as they are toxic, even at low concentration levels [5]. In general, the toxicity of heavy metals is due to the chemical reactivity of the ions with cellular structural proteins, enzymes, and membrane systems [6]. Metals are nonbiodegradable and are cumulative in nature rendering them persistent pollutants [7]. The safety and quality of medicinal herbal products have become a major concern for health authorities, pharmaceutical industries, and the general public. The toxicity of herbal plants may be related to contaminants such as pesticides, microbes, heavy metals, chemical toxins, and adulterants [3,8]. Apart from affordability and availability, the advocates of herbal products believe that they are safe and harmless because of their natural origin without any scientific evaluation. But, most of the herbal products contain a toxic concentration of heavy metals. Heavy metals like lead, cadmium, and chromium are lethal and toxic to humans even at lower concentrations [9–11]. Previous studies conducted globally showed that herbal preparations contain heavy metals beyond the World Health Organization (WHO) maximum permissible limit. For example, a study in Nigeria showed that 100% of the samples analyzed contained cadmium above the WHO permissible limits (0.3 mg/kg) and 33% of the samples contained lead above the WHO permissible limits (10 mg/kg) [12]. A study in the United Arab Emirates also suggested that most of the analyzed herbs contained unsafe levels of heavy metals that exceeded the WHO permissible limits (3). A similar study done in North Gondar, Ethiopia, on ten selected medicinal plants indicated that arsenic (20%), cadmium (70%), and lead (30%) were found to contain concentrations above the WHO maximum permissible limit [13]. Among the analytical techniques available for quantifying trace elements in environmental samples, inductively coupled plasma optical emission spectrometry (ICP-OES) is the most powerful and popular technique. It allows multielement analysis with good detection capabilities, wide working ranges, and high sensitivity with relatively high freedom from nonspectral interference [14]. Herbal preparations are becoming widely used in Dessie and Kombolcha town, Northeast Ethiopia, to treat several ailments such as cough, diarrhea, fever, sexually transmitted diseases, sexual impotency, hypertension, cancer, and diabetes. However, there is currently no national policy to guide the regulation and monitoring of the quality and safety of traditional herbal preparations in Ethiopia. Therefore, very limited information is available on the safety of herbal preparations sold in the Ethiopian market. Hence, the objective of this study was to assess the level of heavy metals (Pb, Cd, Cr, and Cu) in herbal preparations sold in Northeast Ethiopia and to estimate their health risks associated with their daily intake. 2. Materials and Methods 2.1. Materials 2.1.1. Instruments and Apparatus Microwave plasma atomic emission spectroscopy (Agilent MP-AES 4210, USA), vacuum oven (digital heat j.p. Selecta, Spain), hotplate (digital timer function hotplate, Thermo Scientific, USA), digital analytical balance (Mettler Toledo Me204, Switzerland), Whatman filter paper (Whatman TM No. 41, 150 mm diameter, GE Healthcare UK Limited), porcelain/ceramic mortar and pestle, grade A volumetric flasks of 50 ml, 100 ml, 500 ml, and 1000 ml (Pyrex, USA), grade A volumetric pipette of 0.5 ml, 1 ml, and 5 ml and a beaker of different sizes (Pyrex, USA), Teflon beaker (plastic wear PTFE beaker, UK), and vortex shaker (Mfr, S1-S1-p236, USA) were used for a multielemental analysis of heavy metals. 2.1.2. Chemicals and Reagents Analytical grade chemicals and reagents were used throughout the experiment. Chemicals and reagents used for this particular experiment were hydrochloric acid (37%, Sigma Aldrich product of USA), nitric acid (70%, Sigma Aldrich product of USA), and ultrapure water (Milli-Q TM water system Darmstadt, Germany) used for standard solution preparation. Distilled water and stock solution of standard Pb, Cd, Cr, and Cu (BDH, Chemicals, Ltd., Merck, England) were obtained from the Ethiopian Public Health Institute (EPHI) laboratory, Addis Ababa, Ethiopia. 2.2. Methods 2.2.1. Study Area and Period The study was conducted in Dessie and Kombolcha town, South Wollo zone, Amhara region, Northeast Ethiopia, from October 2019 to July 2020. South Wollo zone is one of the six zones of the Amhara region, Northeast Ethiopia. Dessie, the capital city of South Wollo zone, is 401 km far from Addis Ababa, the capital city of Ethiopia, and 540 km far from Bahir Dar, the capital city of Amhara regional state. Kombolcha is an industrial town in the east Amhara region, Northeast Ethiopia, and is located 18 km far from Dessie town. The major natural vegetation of the study areas is characterized by grassland (grazing areas) and small forests containing mainly acacia trees and shrub species. A large part of the study area is covered with agricultural farm areas. The study areas were selected because traditional herbal products were commonly used by the community to treat chronic diseases such as hypertension, diabetes mellitus, and cancer. According to the city administrative health office report, there are 29 officially licensed traditional practitioners in Dessie and Kombolcha town during this study. 2.2.2. Sample Collection A total of six traditional herbal preparations frequently used in the treatment of hypertension, diabetes mellitus, malaria, sexual dysfunction, kidney, and GI problems in Dessie and Kombolcha town, Northeast Ethiopia, were included in this study. Herbal samples were commercially available in powder form in plastic containers. About 150 g of each herbal preparation was purchased randomly from six different herbal shops of Dessie and Kombolcha town from February 1 to 21, 2020. Each collected sample was randomly coded from KD-01 to KD-02 and was stored in polyethylene bags for further analysis [15]. The experimental work for the determination of heavy metals was conducted at the food and drug quality control laboratory of the Ethiopian Public Health Institution (EPHI), Addis Ababa, Ethiopia. Sample code, the composition of herbal preparations, their traditional use, and collection areas are summarized in Table 1. Sample code Composition of herbal preparations Traditional use Collection area KD-01 Aloe Percrassa, Verbascum sinaiticum Sexual impotency Kombolcha KD-02 Chenopodium murale Kidney problem Dessie KD-03 Urtica simensis, Trigonella Foenum-graceeum, Calpurnia aurea Peptic ulcer disease Dessie KD-04 Verbena officinalis, Dodonaea angustifolia, Calpurnia aurea Gastrointestinal problem Dessie KD-05 Carica papaya, Dodonaea angustifolia Malaria and diabetes mellitus Kombolcha KD-06 Rumex abyssinicus, Trigonella Foenum-graceeum, Thymus vulgaris Hypertension Dessie
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