The objective of this study was to assess the presence of potentially harmful substances in specific Nigerian poly-herbal formulations and to evaluate the associated health risks by calculating their carcinogenic and non-carcinogenic indices. Four poly-herbal formulations were acquired at random from Cynflac Pharmacy in Yenagoa, Bayelsa State.The samples underwent wet digestion for analysis, and the presence of potentially harmful components was assessed using Atomic Absorption Spectroscopy (AAS). The human health risk associated with the administration of the analysed poly-herbal formulations was evaluated by computing non-carcinogenic estimated daily intake (EDI), Target hazard quotients (THQ), and Hazard Index (HI), as well as carcinogenic risks. The concentrations of potentially harmful elements ranged from 0.036 to 0.26 mg/kg for Cd, 0.003 to 0.54 mg/kg for Cr, 0.37 to 0.52 mg/kg for Ni, 0.13 to 1.5 mg/kg for Cu, 0.002 to 1.4 mg/kg for Pb, 0.43 to 2.8 mg/kg for Zn, 0.54 to 0.86 mg/kg for Mn, and 4.4 to 6.5 mg/kg for Fe. Nevertheless, Nickel was not identified in the Rz and Jn poly-herbal formulations. The investigation indicated that the concentrations of Cd, Cr, Cu, Pb, and Zn were within the permitted limits set by the World Health Organisation (WHO). The concentrations of Ni (Gk and Yy), Mn, and Fe were found to exceed the permitted limits set by the World Health Organisation (WHO). From a perspective of human health, the evaluations of non-carcinogenic risk were found to be within acceptable limits and were lower than 1. However, the evaluation of carcinogenic risk revealed that a majority of the samples of the poly-herbal formulation exceeded the average incremental lifetime cancer risk of 10 − 4. According to the findings of this study, consuming these poly-herbal formulations may provide a cancer-causing health risk to the consumer. Hence, it is imperative to implement a consistent and rigorous regulatory oversight to guarantee the safety of poly-herbal formulations and consumers in Nigeria.
Research Article
Assessment of Potentially Toxic Elements (PTEs) and Human Health Risk Impact of Some Nigerian Poly-Herbal Formulations
https://doi.org/10.21203/rs.3.rs-4940337/v1
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Heavy metals
Carcinogenic risk
Non-carcinogenic risk
Herbal products
The World Health Organisation estimates that between seventy and eighty percent of the world's population uses herbal remedies primarily. It is possible for herbal treatments to have hazardous components such pesticide residues, poisonous metals, and other contaminants. The safety of these items is compromised in many African nations due to a lack of or insufficient quality control measures, even though they are extensively utilised and greatly contribute to primary health care. Toxic to both humans and other forms of life, heavy metals are defined as metals with a density more than 5 g/cm3 (WHO 2007).
Heavy metals are essential for plant and human health, but only in minute concentrations. Copper (Cu), chromium (Cr), fluorine (F), molybdenum (Mo), nickel (Ni), selenium (Se), and zinc (Zn) are micronutrients that can be toxic to plants and animals in excess. Even minute concentrations of arsenic, cadmium, mercury, and lead can cause injury (Divriki et al., 2006). Heavy metals cannot be removed by routine crop cultivation or simply rinsed away by rainfall because of their persistence and non-biodegradability. Measuring the amounts of heavy metals in publicly supplied food is becoming more popular. While metal concentration is an important consideration, the availability of a bio-available form of the metal is not necessarily indicative of this (Opaluwa et al. 2012).
Heavy metal exposure can damage the makeup of vital organs including the brain, lungs, liver, and kidneys, as well as impact cognitive and CNS function, energy levels, and overall health. Prolonged and frequent exposure to certain heavy metals or their compounds can lead to the development of cancer (Ogidi and Tawariowei 2023), as well as contact dermatitis and skin irritation caused by chromium (Cr), nickel (Ni), and cobalt (Co). Nevertheless, their level of exposure persists and is even on the rise, especially in underdeveloped nations (Duruibe et al. 2007; Linnila 2000).
There is a growing global trend towards the utilisation of herbal combinations. The rise in popularity of herbal products is driven by the perception that they are safe, easily obtainable, and cost-effective compared to expensive synthetic drugs that are believed to have negative effects. However, recent research has revealed varying levels of contamination in herbs and herbal products, including heavy metals and other impurities (Ogoun et al. 2022a,b; Ogidi et al. 2022). The recognition of these poly-herbal formulations as effective in enhancing healthcare, mostly due to their secondary bioactive substances (Ogidi and Joshua 2023, 2024), has led to the emergence of fresh herbal formulations in the market. Several of these herbal products have received safety and quality certification. Certain items have not undergone testing and their usage is not supervised. This hampers the comprehension of the potential dangers linked to its utilisation (Nwachukwu et al. 2010).
Hence, it is imperative to conduct a thorough evaluation of the quality and safety of products in order to ascertain the existence and levels of heavy metals, which can represent substantial health hazards to individuals. While poly herbal formulations are widely recognised for their strong therapeutic potential, their safety and quality testing is typically not as thorough as that of conventional pharmaceuticals. Multiple studies in scientific literature have shown that herbal remedies contain heavy metals at levels that exceed the permitted limits established by the World Health Organisation (WHO). These highlight the importance of regularly testing herbal formulations for the presence of heavy metals, in order to provide regulatory bodies and the public with information about the potential risks connected with their use. The objective of this study was to analyse the levels of potentially harmful ingredients in four poly-herbal formulations available in the Nigerian market and evaluate their influence on human health.
2.1. Sample Collection
The selected Nigerian Herbal formulations that were used in this study were purchased in Cynflac Pharmacy, Imiringi road, Yenagoa, Bayelsa State. The poly-herbal formulations were coded as Gk, Yy, Rz, and Jn and was taken to the laboratory for potentially toxic elements analysis.
2.2. Samples Preparation and Procedure
The wet digestion method was employed to prepare the herbal formulations for the purpose of analysing heavy metals. Five millilitres (5 ml) of the analytical unit (sample) were measured and placed into a digestive tube. Then, a mixture of digestion acids, consisting of 20 millilitres (20 ml) of HNO3, H2SO4, HCl, and HClO4 at a ratio of 1:3:1:1, was added. The sample was further processed using the FOSS TECATOR Digester Model 210 at a temperature of 250°C for a duration of 1 hour, and this process was repeated until a transparent solution was achieved in a fume cupboard. The transparent solution was strained into a 100 ml volumetric flask and filled up to the designated level with de-ionised water.
2.3. Determination of Potentially toxic elements
The digested samples were analysed in triplicate using an Atomic Absorption Spectrophotometer (Buck 210). A standard solution was prepared for each element being studied, with a concentration of mgl/100 g. The concentration limit specified by BUCK Scientific instruction was followed for each element. The obtained results were then compared to the metal limits for human consumption set by the World Health Organisation.
2.4. Quality assurance protocol and statistical analysis
The reliability of the results was ensured by implementing stringent quality assurance methods and safeguards. Every precaution was taken to ensure that the samples were free of contaminants. For 48 hours, a solution containing 1 mol/L of HNO3 was submerged in the glassware and sample containers. Afterwards, ultrapure water was used to wash them thoroughly. Keep in mind that high-quality analytical reagents were utilised. Execution of recovery tests evaluated the analytical method's accuracy and precision. Analysing the recovery data revealed that the digesting processes were accurate. To do this, portions of metal standards were added to the samples that were already tested and then reanalysed. Relative standard deviations were less than eleven percent, and the recovery rate was over ninety-five percent, indicating pinpoint accuracy. The data was presented using SPSS Statistic 17.0 as the mean value plus or minus the standard deviation (SD).
2.5. Human health risk assessment
Equation 1 was used to estimate the EDI of toxic metals, the Target Hazard Quotient (THQ), the Hazard Index (HI), and the Carcinogenic Risk (CR), which were then used to assess the potential risks to human health from consuming poly-herbal formulations containing potentially harmful elements.
2.5.1. Estimated Daily Intake (EDI)
Where:
Cmetal represents the concentration of metal in the formulations, measured in milligrammes per kilogramme (mg/kg).
Dherbal formulation intake refers to the daily consumption of the herbal formulation, measured in kilogrammes per person (kg person-1).
BWaverage represents the average body weight of a person, measured in kilogrammes per person (kg person-1).
For this study, participants consumed a daily average of a herbal formulation at a rate of 3.6 litres per kilogramme of body weight. In 2001, Obot conducted a study which found that the mean body weight for adults was 60 kg, whilst children had an average body weight of 15 kg.
2.5.2. Non-carcinogenic health effect
The Target Hazard Quotient (THQ) was used to estimate the non-carcinogenic risk associated with the consumption of hazardous metals. The THQ, or Toxic Hazard Quotient, is a measure of the ratio between the dose of a toxic substance and a reference amount that is known to be harmful. If the ratio is 1 or higher, an exposed population is in danger. The THQ values were computed using Eq. 2 as described by Singh et al. in their 2010 publication.
Where:
Efr represents the frequency of exposure in 190 days per year. ED represents the length of exposure, which is similar to an average lifetime of 56 years. FIR is the average daily intake in kilogrammes per person per day.
C represents the concentration of metal in the herbal formulation sample, measured in milligrammes per kilogramme (mg/kg).
Rf The term "reference dose" refers to the amount of a substance, measured in milligrammes per kilogramme per day, that is considered safe for daily consumption.
The ATn represents the average duration of exposure to non-carcinogens, measured in days, and is calculated as the product of 190 and 56.
The following reference doses were used: Cu = 0.040 mg/kg, Ni = 0.020 mg/kg, Cr = 0.5 mg/kg, Mn = 0.014 mg/kg, Zn = 0.300 mg/kg, and Fe = 0.700 mg/kg (WHO 1992; USEPA 2011). The hazard index is a way to evaluate the possible harm to human health when multiple hazardous metals are present. It was calculated by adding up the target hazard quotients (THQs), as described by Abou-Arak in 2001. Since multiple contaminants might have similar negative health impacts, it is often appropriate to aggregate THQs linked to multiple substances, as shown in Eq. 3.
2.5.3. Carcinogenic health effect
The incremental lifetime cancer risk of an individual is the likelihood that they will develop cancer of some form during their lifespan as a result of the cumulative impact of daily exposure to a carcinogen. By estimating the lifetime risk of cancer from oral exposure to specific pollutants at varying concentrations, the Cancer Slope Factor (CSF) determines the ILCR. This evaluation was reported by the ATSDR in 2010 and is tailored to each pollutant. The cancer slope factors for ingesting are quantified using the milligrammes per kilogramme per day (mg/kg/day) unit.The probability of malignancy was determined by employing Eq. 4.
Where:
EDI refers to the expected daily intake of each heavy metal, measured in milligrammes per kilogramme per day.
CSFing refers to the ingestion cancer slope factor, which is measured in units of milligrammes per kilogramme per day raised to the power of negative one.
The United States Environmental Protection Agency (2011) states that carcinogens have to fall between the permissible range of 10 − 6 (1 in 1,000,000) to 10 − 4 (1 in 10,000) for their projected lifetime risks. Further inquiry into compounds of concern can be halted if their risk factor is less than 10 − 6.
3.1. Potentially Toxic Element Profiles
The poly-herbal samples' profiles of potentially hazardous elements are displayed in Table 1. The Cd concentration reached its peak at Yy with a mean value of 0.26±0.01 mg/kg, while it was at its lowest at Jn with a mean value of 0.036±0.001 mg/kg. The highest mean value of Cr was 0.54±0.002 mg/kg (Jn), whereas Yy had the lowest value of 0.005±0.0001. The Mean Ni concentrations were highest in Yy at 0.52±0.002 mg/kg, while Rz and Jn were not found. Rz exhibited the highest reported levels of Cu, with a concentration of 1.5±0.29 mg/kg, whilst Yy had the lowest levels, with a concentration of 0.13±0.002 mg/kg. The highest reported value of Lead was 1.4±0.001 mg/kg for Yy, while the lowest values were seen for Rz and Jn at 0.002±0.0001 mg/kg. The greatest mean value for Zn was 2.8±0.01 mg/kg, observed in Yy. On the other hand, the lowest mean value of 0.43±0.01 mg/kg was found in Gk. The highest manganese (Mn) concentrations were found in Jn (0.86±0.02 mg/kg), whereas Gk had the lowest concentration (0.54±0.01 mg/kg). The Yy group had the highest Mean Fe levels (6.5±0.02 mg/kg), whereas the Gk group had the lowest levels (4.4±0.02 mg/kg).
Table 1: Potentially toxic elements of some selected Nigerian Poly-herbal Formulations
|
Sample Code |
Potentially toxic elements mg/kg |
|||||||
|
Cd |
Cr |
Ni |
Cu |
Pb |
Zn |
Mn |
Fe |
|
|
Rz |
0.055±0.002 |
0.3±0.003 |
ND |
1.5±0.29 |
0.002±0.0001 |
0.5±0.02 |
0.74±0.02 |
5.1±0.02 |
|
Gk |
0.22±0.002 |
0.003±0.009 |
0.37±0.002 |
0.14±0.001 |
0.97±0.001 |
0.43±0.01 |
0.54±0.01 |
4.4±0.02 |
|
Yy |
0.26±0.01 |
0.005±0.0001 |
0.52±0.002 |
0.13±0.002 |
1.4±0.001 |
2.8±0.01 |
0.68±0.02 |
6.5±0.02 |
|
Jn |
0.036±0.001 |
0.54±0.002 |
ND |
0.18±0.002 |
0.002±0.0001 |
1.8±0.02 |
0.86±0.02 |
4.9±0.01 |
|
WHO |
0.3 |
2.0 |
0.02 |
2.0 |
10.0 |
3.00 |
0.1 |
0.3 |
Note: Mean±SD, WHO- World Health Organization
3.2. Health Risks to consumers from Potentially toxic elements ingestion of Poly-herbal formulation for adult and children
Individuals of all age groups The results obtained from the samples of the poly-herbal formulation indicated that the Estimated Daily Intake (EDI) values of the potentially dangerous components were found to be within the permissible limits set for daily intake, as specified in Tables 2 and 3. Tables 4 and 5 indicate that the THQ and HI values for both adults and children were below 1.The poly-herbal formulation samples showed carcinogenic risk (CR) values larger than 1×10-4 for Cd, Cr, Ni, Zn, Fe, and Mn. Additionally, Cu (Rz) and Pb (Yy-adult, Gk, and Yy-children) values were also greater than 1×10-4, as indicated in Tables 6 and 7.
Table 2: Estimated Daily Intake (EDI) of potentially toxic elements for adult from ingestion of some selected Nigerian Poly-herbal formulations
|
Sample Code |
Potentially toxic elements |
|||||||
|
Cd |
Cr |
Ni |
Cu |
Pb |
Zn |
Mn |
Fe |
|
|
Rz |
0.00063 |
0.0035 |
- |
0.017 |
2.3E-5 |
0.0058 |
0.0085 |
0.0059 |
|
Gk |
0.0026 |
3.9E-5 |
0.0043 |
0.0016 |
0.011 |
0.0049 |
0.0062 |
0.051 |
|
Yy |
0.0030 |
5.8E-5 |
0.006 |
0.0015 |
0.016 |
0.033 |
0.0078 |
0.075 |
|
Jn |
0.00042 |
0.0063 |
- |
0.0021 |
2.3E-5 |
0.021 |
0.0099 |
0.056 |
Table 3: Estimated Daily Intake (EDI) of potentially toxic elements for children from ingestion of some selected Nigerian Poly-herbal formulations
|
Sample Code |
Potentially toxic elements |
|||||||
|
Cd |
Cr |
Ni |
Cu |
Pb |
Zn |
Mn |
Fe |
|
|
Rz |
0.00091 |
0.0051 |
- |
0.025 |
3.3E-5 |
0.0083 |
0.012 |
0.085 |
|
Gk |
0.0037 |
5.6E-5 |
0.0062 |
0.0023 |
0.0162 |
0.0072 |
0.009 |
0.073 |
|
Yy |
0.0033 |
8.3E-5 |
0.0087 |
0.0022 |
0.023 |
0.047 |
0.011 |
0.11 |
Table 4: Target hazard quotient (THQ) and hazard index (HI) for adult exposed to Nigerian Poly-herbal formulations
|
Sample Code |
Potentially toxic elements |
HI |
|||||||
|
Cd |
Cr |
Ni |
Cu |
Pb |
Zn |
Mn |
Fe |
||
|
Rz |
5.3E-5 |
3.3E-7 |
- |
9.7E-5 |
1.8E-8 |
1.5E-6 |
6.9E-5 |
6.6E-6 |
0.0022 |
|
Gk |
8.9E-5 |
4.1E-10 |
1.2E-5 |
8.6E-7 |
0.00041 |
1.1E-6 |
3.7E-5 |
4.2E-5 |
0.0023 |
|
Yy |
0.00012 |
8.9E-8 |
2.5E-5 |
7.6E-7 |
0.00086 |
4.8E-5 |
5.8E-5 |
0.00011 |
0.0024 |
|
Jn |
2.3E-6 |
1.1E-6 |
- |
1.5E-6 |
1.8E-8 |
1.9E-5 |
9.4E-5 |
5.9E-5 |
0.0018 |
Table 5: Target hazard quotient (THQ) and hazard index (HI) for children exposed to Nigerian Poly-herbal formulations
|
Sample Code |
Potentially toxic elements |
HI |
|||||||
|
Cd |
Cr |
Ni |
Cu |
Pb |
Zn |
Mn |
Fe |
||
|
Rz |
3.3E-5 |
2.0E-6 |
- |
0.00062 |
1.1E-7 |
9.2E-6 |
0.00042 |
0.00041 |
0.0019 |
|
Gk |
0.00055 |
2.5E-9 |
7.7E-5 |
5.4E-6 |
0.0026 |
6.9E-6 |
0.00023 |
0.00030 |
0.0046 |
|
Yy |
0.00058 |
5.5E-9 |
0.00015 |
4.8E-6 |
0.0053 |
0.00029 |
0.00036 |
0.00068 |
0.0074 |
Table 6: Carcinogenic Risk for adult exposed to some Nigerian Poly-herbal formulations
|
Sample Code |
Potentially toxic elements |
|||||||
|
Cd |
Cr |
Ni |
Cu |
Pb |
Zn |
Mn |
Fe |
|
|
Rz |
0.00024 |
0.0018 |
- |
0.00068 |
1.9E-6 |
0.0017 |
0.00012 |
0.0041 |
|
Gk |
0.00099 |
0.00019 |
0.0036 |
6.4E-5 |
9.4E-5 |
0.0015 |
8.7E-5 |
0.036 |
|
Yy |
0.0011 |
0.00029 |
0.0050 |
6E-5 |
0.00014 |
0.0099 |
0.00011 |
0.053 |
|
Jn |
0.00016 |
0.0032 |
- |
8.4E-5 |
1.9E-6 |
0.0063 |
0.00014 |
0.0392 |
Table 7: Carcinogenic Risk for children exposed to some Nigerian Poly-herbal formulations
|
Sample Code |
Potentially toxic elements |
|||||||
|
Cd |
Cr |
Ni |
Cu |
Pb |
Zn |
Mn |
Fe |
|
|
Rz |
0.00035 |
0.0025 |
- |
0.001 |
2.8E-6 |
0.0025 |
0.00017 |
0.0595 |
|
Gk |
0.0014 |
0.00028 |
0.0052 |
9.2E-5 |
0.00014 |
0.0022 |
0.00013 |
0.0511 |
|
Yy |
0.0013 |
0.00042 |
0.0073 |
8.8E-5 |
0.00019 |
0.0141 |
0.00015 |
0.077 |
4.1. Potentially Toxic Element Profiles
Herbal medications possess diverse physiological actions and can be employed in the treatment of many medical situations (Pieme et al., 2006). Without taking into account adequate dosage, monitoring, and assessment of harmful consequences, these medications could be given for an extended period of time in various illness situations (Ogbonnia et al. 2010). The atmosphere and soil are becoming contaminated with chemicals and heavy metals as a result of the rapid growth of industry and agricultural practices, including the widespread application of pesticides and fertilisers. These contaminants and accumulations of toxic metals enter the human food chain through plant components and/or extracts. Certain herbal medications lack sufficient study and are not subject to regulation in terms of their composition and sale. According to Oshikoya et al. (2008), there is a possibility that they have been contaminated and are therefore at danger of causing harmful effects and toxicity. The current study has emphasised the profiles of potentially harmful elements, as well as the cancer-causing and non-cancer-causing impacts of poly-herbal formulations in Nigeria.
The poly-herbal formulation samples had lead concentrations ranging from 0.002 ± 0.001 to 1.4 ± 0.001 mg/kg (Table 1). The Yy, Rz, and Jn samples had the highest and lowest amounts. The World Health Organisation (WHO) has set a maximum allowable limit of 10 mg/kg for lead (Pb) in traditional herbal remedies, as stated in the WHO 2007 guidelines. The concentration of lead, a substance known to induce renal failure and liver damage in humans, was found to be within the permitted level set by the World Health Organisation (WHO) in this investigation. Maghrabi (2014) found comparable outcomes in other samples of herbal medications sold in Saudi Arabia, where the levels of Pb were below the legal limit set by the World Health Organisation (Maghrabi 2014).
Exposure to elevated levels of cadmium is widely recognised to be very toxic and carcinogenic. Ingesting it in small amounts can lead to the accumulation of the substance in the kidneys, causing harm to the renal tract, lungs, and bones (Mahurpawar 2015; Ekeanyanwu et al. 2013; Mulaudzi et al. 2017). The World Health Organisation (WHO) has set a maximum allowable limit of 0.3 mg/kg for cadmium in traditional herbal preparations [1]. The concentration of cadmium in this investigation was found to be within the permitted limit, as indicated in Table 1. Alhusban et al. (2019) have reported similar findings in Jordan, whereas Zamir et al. (2015) have reported similar findings in Bangladesh, and Samali et al. (2017) and Dee et al. (2019) have reported similar findings in Nigeria.
The concentration of copper varies from 0.13 ± 0.002 mg/kg in the Yy sample to 1.5 ± 0.29 mg/kg in the Ruzu samples. The quantities in the samples were found to be lower than the acceptable threshold of 2 mg/kg for herbal formulations, as advised by the World Health Organisation (WHO 2007). Copper is a vital component for the human metabolic system. It controls a range of biological activities such as redox reactions, energy generation, creation of connective tissue, iron metabolism, and synthesis of neurotransmitters (Ekeanyanwu et al., 2013). Nevertheless, prolonged exposure to a substantial amount of copper leads to inflammation of the nasal lining, vomiting, feelings of sickness, diarrhoea, and harm to the kidneys and liver (Ekeanyanwu et al. 2013; Zamir et al. 2019).
The investigation determined the concentration of chromium to be within the range of 0.003 ± 0.009–0.54 ± 0.002 mg/kg (Table 1). The Jn sample had the greatest reported amount, while the Gk sample had the lowest recorded amount. The concentration of chromium in herbal products was found to be within the permitted limits specified by the World Health Organisation (2 mg/kg) (WHO 2007). Exposure to elevated amounts of chromium can lead to respiratory tract issues, lung cancer, dermatitis, and irreversible nasal damage (Mulaudzi et al., 2017). The health hazard associated with metal pollution is mostly determined by the average daily consumption of metals in one's diet. Chromium is highly deadly and toxic to humans, even at lower quantities. The findings corroborate the reports of Idu et al. (2015).
Zinc (Zn) is a vital component of numerous plant proteins, but can be harmful when present in excessive amounts. The Zinc level in the samples varies from 0.43 ± 0.01 mg/kg in the Gk sample to 2.8 ± 0.01 mg/kg in the Yy sample. The readings were lower than the permitted limit of 3.0 mg/kg set by the World Health Organisation (WHO). This outcome aligns with the research findings of Idu et al. (2014) and Jones (1987). Zinc exhibits a protective effect against both cadmium and lead. Zinc insufficiency is characterised by a diminished sense of taste, stunted development, and hypogonadism, resulting in reduced fertility. Zinc poisoning is infrequent, but at elevated levels, it can cause toxicity marked by symptoms such as muscular rigidity, irritability, decreased appetite, discomfort, and nausea (Ogidi et al., 2021a).
The nickel values range from 0.37 ± 0.02 mg/kg in Gk to 0.52 ± 0.02 mg/kg in Yy. No Ni concentrations were found in Rz and Jn. The amounts of Ni in Gk and Yy above the permitted limit set by the World Health Organisation, which is 0.02 mg/kg. These findings were consistent with the research conducted by Chukwujindu et al. (2014) and Ogidi et al. (2021b). Nickel has the ability to build up in the kidneys, bones, and thyroid glands, leading to hazardous effects. Nickel is necessary in tiny amounts, but excessive intake can pose a risk to human health (Ogidi et al., 2020).
The investigation determined that the content of Manganese ranged from 0.54 ± 0.01 to 0.86 ± 0.02 mg/kg (Table 1). The Jn sample had the greatest reported amount, while the Gk sample had the lowest recorded amount. The concentration of Manganese in herbal products exceeded the permitted limits established by the World Health Organisation (0.1 mg/kg) (WHO 2007). These results align with the findings of Ogidi et al. (2021a) and Chukwujindu et al. (2014).
Iron toxicity can be categorised as either corrosive or cellular. When iron is consumed, it can cause severe damage to the lining of the gastrointestinal (GI) tract. This can result in symptoms such as nausea, vomiting, stomach discomfort, vomiting blood, and diarrhoea. Additionally, patients may experience low blood volume due to large loss of fluids and blood. Haemochromatosis is a condition that affects the way the body processes iron. It is characterised by the excessive absorption of iron, saturation of iron-binding proteins, and the deposition of haemosiderin in tissues. The liver, skin, and pancreas are the primary tissues that are affected by this disorder (Ogidi et al., 2020). The levels of iron (Fe) in the current investigation exceeded the maximum allowable thresholds set by the World Health Organisation (WHO), which is 0.3 mg/kg. The results are consistent with the research conducted by Bakare-Odunola and Mustapha (2014).
4.2. Human health risk assessment of potentially toxic elements (PTEs)
Estimating health risks by calculating the estimated daily intake (EDI) of heavy metal contaminants is an important approach for assessing health risks. It considers both the frequency and duration of exposure, as well as the bodyweight of the individuals who were exposed. The health risk associated with metal pollution is primarily determined by the average daily dietary intake (Adusei-Mensah et al., 2019). The EDI (Estimated Daily Intake) of all the potentially harmful constituents in the poly-herbal formulation samples, for both adults and children, were found to be below the acceptable limits of daily intake as specified in Tables 2 and 3.
The non-carcinogenic risk associated with potentially harmful ingredients in the poly-herbal formulations for both adults and children was assessed using the Total Hazard Quotient (THQ) and Hazard Index (HI). The findings are presented in Tables 4 and 5. The THQ (Target Hazard Quotient) is used to assess the chronic exposure to potentially harmful ingredients found in poly-herbal formulations, specifically for their non-carcinogenic effects. If the THQ values are below 1, the exposed consumers are considered safe. However, if the THQ values are equal to or greater than 1, it indicates a degree of worry or offers a health risk (Ogidi et al. 2021a; Kohzadi et al. 2019; Adefa and Tefera 2020). The study findings indicate that the THQ values for potentially harmful components in both adults and children were below 1. This suggests that the ingestion of these poly-herbal formulations does not offer any health risks associated with these toxic elements. If the Hazard Index (HI) value of any potentially harmful ingredients in poly-herbal compositions is below 1, it indicates that the population exposed to these elements is unlikely to suffer any negative health consequences over their lifetime. The Hazard Index (HI) values for all the potentially harmful ingredients in the poly-herbal formulations were below 1. This suggests that the cumulative impact of the heavy metal pollutants found in a certain herbal preparation does not create any long-term health hazards for both adults and children. This discovery was consistent with the research conducted by Mihreteab et al. (2020) and Ogidi et al. (2021a).
The combined risk of developing cancer in the majority of the poly-herbal formulation samples for both adults and children exceeded the tolerable thresholds, as seen in Tables 6 and 7. The acceptable risk threshold for carcinogens vary between 10 − 4 (which means a 1 in 10,000 chance of acquiring cancer over a human lifetime) and 10 − 6 (which means a 1 in 1,000,000 chance of developing cancer over a human lifetime) (Ogidi et al., 2021a, b). CR values below 10^-6 are deemed insignificant, values above 10^-4 are deemed unsatisfactory, and values between 10^-6 and 10^-4 are considered within an acceptable range. The elements that have the potential to be poisonous. The poly-herbal formulation samples for adults had Carcinogenic Risk (CR) values in the following order: Yy > Gk > Jn > Rz. The sequence Yy > Rz > Gk represents a series of activities or events specifically designed for youngsters. According to these findings, the poly-herbal formulations have a possible risk of causing cancer. This is because the CR values of most of the potentially harmful ingredients were higher than 1× 10 − 4, as indicated in Tables 6 and 7. The findings indicate a substantial cancer hazard for individuals who consume these poly-herbal mixtures. This result is consistent with the findings of Ogidi et al. (2021a, b).
The objective of this study was to assess the concentration of potentially harmful elements (Cd, Cr, Ni, Cu, Pb, Zn, Mn, and Fe) in commonly used poly-herbal formulations available in Nigeria. The findings of this investigation revealed that the majority of the potentially harmful elements (Cd, Cr, Cu, Pb, and Zn) were detected at levels that were either within or below the acceptable limits set by the World Health Organisation (WHO). No traces of nickel were found in the analysed Rz and Jn samples. Nevertheless, every single sample that was analysed revealed levels of Ni (Gk and Yy), Mn, and Fe that were higher than the permitted limits set by the World Health Organisation. According to the European Food Safety Authority (EFSA) guidelines, the poly-herbal formulation samples did not contain any elements with an Estimated Daily Intake (EDI) that could be detrimental to human health. In other words, these poly-herbal compositions do not present any health risks to adults or children when ingested, as all samples had a Target hazard quotient and Hazard index value below 1. During the cancer risk assessment, it was observed that all of the poly-herbal formulation samples analysed had carcinogenic potency equivalent (PTEs CR) values that exceeded the average incremental lifetime cancer risk of 10 − 4. This implies that individuals who consume these poly-herbal mixtures are at a high risk of developing cancer. The findings of this investigation suggest that the consumption of these poly-herbal blends can result in the development of cancer.
Conflict of interest
The author declared that there are no competing interests for the research work presented here.
Ethical approval
Not applicable
Funding
The study did not receive any sponsor, it was self-sponsored.
Author Contribution
O.I.O. Designed and wrote the manuscript and reviewed the manuscript.
- Abou-Arak AAK 2001 Heavy metal contents in Egyptian meat and the role of detergent washing on their levels. Food ChemToxicol. 39 593-599.
- Adefa T and Tefera M 2020 Heavy metal accumulation and health risk assessment in Moringaoleifera from Awi zone, Ethiopia, Chemistry Africa. 3 1073–1079.
- Adusei-Mensah F, Essumang DK, Agjei RO, et al. 2019 Heavy metal content and health risk assessment of commonly patronized herbal medicinal preparations from the Kumasi metropolis of Ghana, Journal of Environmental Health Science and Engineering. 17(2) 609–618.
- Alhusban AA, Ata SA and Shraim SA 2019 The safety assessment of toxic metals in commonly used pharmaceutical herbal products and traditional herbs for infants in Jordanian market, Biological Trace Element Research. 187(1) 307–315.
- Al-Jassir MS, Shaker A, and Khaliq MA 2005 Deposition of heavy metals on green leafy vegetables sold on roadsides of Riyadh City, Saudi Arabia. Bull Environ ContamToxicol. 75 1020-1027.
- Bakare-Odunola MT and Mustapha KB 2014 Identification and quantification of heavy metals in local drinks in Northern zone of Nigeria. J Toxicol Environ Health Sci. 6 126-131.
- Chukwujindu MAI, Anwuli LO and Francisca IB 2014 A survey of metal profiles in some traditional alcoholic beverages in Nigeria. Food Sci Nutr. 2 724-73.
- Dee KH, Abdullah F, Md Nasir SNA et al. 2019 Health risk assessment of heavy metals from smoked corbicula fluminea collected on roadside vendors at Kelantan, Malaysia, BioMed Research International. 2019(9), 2019.
- Divrikli U, Horzum N, Soylak M, et al. 2006 Trace heavy metalcontents of some spices and herbal plants from western Anatolia,Turkey. Int. J. Food Sci. Technol. 41 712-716.
- Duruibe JO, Ogwuegbu MOC and Egwurugwu JN 2007 Heavy metal pollution and human biotoxiceffects. Int’l J. Physic. Sci. 2(5) 112-118.
- Ekeanyanwu R, Njoku J, Nwodu P et al. 2013 Analysis of some selected toxic heavy metals in some branded Nigerian herbal products, Journal of Applied Pharmaceutical Science. 3(4) 88.
- Idu M, Erhabor J, Timothy O, et al. 2014 Market survey and heavy metal screening of selected medicinal plants sold in some markets in Benin City, Nigeria. Intl J Human, Arts, Med Sci. 2 (2) 7-16.
- Idu M, Oghale OU and Jimoh A 2015 Heavy metals contamination of some polyherbal products from Lagos state, Nigeria. J Ayu Herb Med. 1(2), 45-50.
- Jones JW 1987 Determination of trace elements in food by inductively plasma atomic emission spectrometry. Elements in Health and Disease. 14 18-20.
- Kohzadi S, Shahmoradi B, Ghaderi E, et al. 2019 Concentration, source, and potential human health risk of heavy metals in the commonly consumed medicinal plants, Biological Trace Element Research. 187(1) 41–50.
- Linnila PM 2000 Zinc, lead and cadmium speciation in Deeper water bodies. Lakes and reservoirs: Research and management. 5 26-270.
- Maghrabi IA 2014 Determination of some mineral and heavy metals in Saudi Arabia popular herbal drugs using modern techniques, African Journal of Pharmacy and Pharmacology. 8(36) 893–898.
- Mahurpawar M 2015 Effects of heavy metals on human health, International Journal of Research-Granthaalayah. 530 1–7.
- Mihreteab M, Gebremariam K and Haile K 2020 Health Risk Assessment and Determination of Some Heavy Metals in Commonly Consumed Traditional Herbal Preparations in Northeast Ethiopia. Journal of Chemistry. 8883837 1-7.https://doi.org/10.1155/2020/8883837.
- Mulaudzi RB, Tshikalange TE, Olowoyo JO et al. 2017 Antimicrobial activity, cytotoxicity evaluation and heavy metal content of five commonly used South African herbal mixtures, South African Journal of Botany. 112 314–318.
- Nwachukwu MA, Feng H and Alinor J 2010 Assessment of heavy metal pollution, CSJ. 8(2) 2017.
- Obot IS 2001 Household survey of alcohol use in Nigeria: The middle belt study. In: Demers A, Room R, Bourgault C. surveys of drinking patterns and problems in seven developing countries. Geneva, World Health Organization.
- Ogbonnia SO, Mbaka GO, Igbokwe NH, et al. 2010 Antimicrobial evaluation, acute and subchronic toxicity studies of Leone Bitters, a Nigerian polyherbal formulation in rodents. AgricBiol J. N Am. 1(3) 366-67.
- Ogidi OI and Joshua MT 2023 Investigation of Phytochemical Compounds of Selected Nigerian Poly-Herbal Formulations. Biomed J Sci & Tech Res, 53(1) 44313-44317. https://doi.org/10.26717/BJSTR.2023.53.008345
- Ogidi OI and Joshua MT 2024 Invitro antioxidant and anti-inflammatory activities of selected polyherbal formulations sold in Nigeria. Future Natural Products. 9(2) xxx-xxx. https://doi.org/10.34172/fnp.2307-1252
- Ogidi OI and Tawariowei AM 2023 Endocrine Disrupting Chemicals and their Role in Cancer-A review. Molecular Sciences and Applications. 3:5-14. DOI: 10.37394/232023.2023.3.2
- Ogidi OI, Enenebeaku UE, Okara E, et al. 2021a Toxic Metal Profiles, Carcinogenic and Non-Carcinogenic Human Health Risk Assessment of Some Locally Produced Beverages in Nigeria. J Toxicol Risk Assess. 7 039. https://doi.org/10.23937/2572-4061.1510039
- Ogidi OI, Frank-Oputu A, Oluwatoyin OS, et al. 2022 Biochemical study on the effects of Ruzu Herbal Bitters Formulation on Wistar Albino Rats. Biomedical Journal of Scientific & Technical Research. 41(1) 32434-32439. https://www.doi.10.26717/BJSTR.2022.41.006558
- Ogidi OI, Njoku CO, Onimisi AM, et al. 2021b Evaluation of Heavy Metal Contents and Potential Human Health Risk Assessment of Selected Canned Sardines Fish Sold in Yenagoa, Nigeria. Archives of Ecotoxicology. 3(2) 39-43.https://doi.org/10.36547/ae.2021.3.2.39-43
- Ogidi OI, Omu O, Njoku CO, et al. 2020 Evaluation of Heavy metal contaminations of selected Alcoholic and Non-Alcoholic drinks sold in Nigeria. International Journal of Research and Scientific Innovation. 7(4) 176-179.
- Ogoun TR, Ogidi OI and Aye T 2022 Toxicity studies of Yoyo Cleanser Bitters Poly-herbal formulation in Albino Rats. World Journal of Pharmaceutical Research. 11(1) 1-11. https://www.doi.10.20959/wjpr20221-22534
- Ogoun TR, Ogidi OI and Frank-Oputu A 2022 Safety Evaluation of Dr. IguedoGoko Cleanser Poly-Herbal Formulation in Wistar Albino Rats. World Journal of Pharmacy and Pharmaceutical Sciences. 11(2) 41-51. https://www.doi.10.20959/wjpps20222-21145
- Opaluwa OD, Aremu MO, Ogbo LO, et al. 2012 Heavy metals concentration of soil, plant leaves and crops grown around dump sites in Lafia metropolis, Nasara State, Nigeria, Pelagia Research Library, Advances in Applied Science Research. 3 (2) 80-784.
- Oshikoya KA, Senbanjo IO, Njokanma OF, et al. 2008 Use of complementary and alternative medicines for children with chronic health condition in Lagos, Nigeria. BMC Compl Alt med. 8(66) 8-20.
- Pieme CA, Penlap VN, Nkegoum B, et al. 2006. Evaluation of acute and subacute toxicities of aqueous ethanolic extract of leaves of Senna alata (L.) Roxb (Casalpiniaceae). AfrJ.Biotech. 5 283-89.
- Samali A, Mohammed M and Ibrahim M 2017 Analysis of heavy metals concentration in Kano herbal preparations for major disease conditions, Chem Search Journal. 8(2) 22–28.
- Singh A, Sharma RK, Agarwal M, et al. 2010 Risk assessment of heavy metal toxicity through contaminated vegetables from waste water irrigated area of Varanasi, India. Trop Ecol. 51 275-387.
- USEPA 2011 Risk-based concentration table. United State Environmental Protection Agency, Washington, USA.
- WHO 1992 Cadmium Environmental Health Criteria, Geneva: World Health Organization, Switzerland, 134.
- WHO 2007 Guidelines for assessing quality of herbal medicines with reference to contaminants and residues.World Health Organisation, Geneva.
- Zamir R, Hosen A, Ullah MO et al. 2015 Microbial and heavy metal contaminant of antidiabetic herbal preparations formulated in Bangladesh, Evidence-Based Complementary and Alternative Medicine. 2015(9) 2015.
- Zamir R, Islam N and Faruque A 2019 Comparison of toxic metal concentrations in antidiabetic herbal preparations (ADHPs) available in Bangladesh using AAS and XRF analytical tools, 2e Scientific World Journal. 19 23-31.
No competing interests reported.