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Health Risk Assessment of Insulin supporting Trace Elements in Commonly Consumed Anti-diabetic Medicinal Plants in Nigeria

London Journal of Research in Science: Natural and Formal
Volume | Issue | Compilation
Authored by Ibrahim Birma Bwatanglang , T.S Magili
Classification: NA
Keywords: Anti-diabetes. Trace elements. Risk assessment. Estimated daily intake. Target hazard quotient.
Language: English

In this study, the longtime dietary exposure of insulin supporting elements in anti-diabetic plants are investigated with a view to establish their essentiality in the management of diabetes mellitus (DM) and potential health risk on consumption. Ten anti-diabetic plants were analyzed for manganese (Mn), iron (Fe), Cobalt (Co), chromium (Cr), zinc (Zn) and vanadium (V) using instrumental neutron activation analysis (INAA) and their respective concentrations were used to estimate their daily intake (EDI) levels. The EDI of Mn was found to be above the reference dose (RfD) of 0.014 mg/kg/day. The highest EDI was found in Hymenocardia acida (HA) (40.43 mg/kg/day). The EDI for Fe shows Ageratum conyzoide (AC) containing the highest EDI of 84.42 mg/kg/day. This value in addition to the EDI of the other species all falls above the RfD for Fe (0.007 mg/kg/day). The EDI for Co in most of the anti-diabetic plants investigated falls below the RfD levels (0.03 mg/kg/day) except for Jatropha gossypiifolia (JG) (0.603 mg/kg/day), Sarcocephalus latifolius (SL) (0.855 mg/kg/day) and Sclerocarya birrea (SB) (0.472 mg/kg/day) respectively. Furthermore, all the EDI recorded for chromium (Cr) in the respective anti-diabetic plants falls below the RfD (1.5 mg/kg/day) levels except in Sarcocephalus latifolius (LH) (8.66 mg/kg/day). The EDI for Zn in all the respective anti-diabetic plants were found to be above the RfD (0.30 mg/kg/day). The results shows the highest EDI of 2.43 mg/kg/day in Balamites aegyptiacae (BA). Furthermore, the highest EDI for V was found in the extract of SL (0.673 mg/kg/day. However, not all the anti-diabetic plants shows a target hazard quotient (THQ) value less (<1) than one. A THQ greater (>) than one for Cr was observed in LH (12.95). The health index (HI) further shows a high level of concerns in LH (13) and in JG (1.36) due to the cumulative effects of the respective metals. Based on the THQ and HI values, it will suffice to conclude that these plants are more or less considered safe for human consumption except from Cr in LH whose THQ and HI values signal potential health risk.

               

Health Risk Assessment of Insulin Supporting Trace Elements in Commonly Consumed Anti-Diabetic Medicinal Plants in Nigeria

I.B Bwatanglangα  & T.S Magiliσ

____________________________________________

ABSTRACTS

In this study, the longtime dietary exposure of insulin supporting elements in anti-diabetic  plants are investigated with a view to establish their essentiality in the management of diabetes mellitus (DM) and potential health risk on consumption. Ten anti-diabetic plants were analyzed for manganese (Mn), iron (Fe), Cobalt (Co), chromium (Cr), zinc (Zn) and vanadium (V) using instrumental neutron activation analysis (INAA) and their respective concentrations were used to estimate their daily intake (EDI) levels. The EDI of Mn was found to be above the reference dose (RfD) of 0.014 mg/kg/day. The highest EDI was found in Hymenocardia acida (HA) (40.43 mg/kg/day). The EDI for Fe shows Ageratum conyzoide (AC) containing the highest EDI of 84.42 mg/kg/day. This value in addition to the EDI of the other species all falls above the RfD for Fe (0.007 mg/kg/day). The EDI for Co in most of the anti-diabetic plants investigated falls below the RfD levels (0.03 mg/kg/day) except for Jatropha gossypiifolia (JG) (0.603 mg/kg/day), Sarcocephalus latifolius (SL) (0.855 mg/kg/day) and Sclerocarya birrea (SB) (0.472 mg/kg/day) respectively. Furthermore, all the EDI recorded for chromium (Cr) in the respective anti-diabetic plants falls below the RfD (1.5 mg/kg/day) levels except in Sarcocephalus latifolius (LH) (8.66 mg/kg/day). The EDI for Zn in all the respective anti-diabetic plants were found to be above the RfD (0.30 mg/kg/day). The results shows the highest EDI of 2.43 mg/kg/day in Balamites aegyptiacae (BA). Furthermore, the highest EDI for V was found in the extract of SL (0.673 mg/kg/day. However, not all the anti-diabetic plants shows a target hazard quotient (THQ) value less (<1) than one. A THQ greater (>) than one for Cr was observed in LH (12.95). The health index (HI) further shows a high level of concern in LH (13) and in JG (1.36) due to the cumulative effects of the respective metals. Based on the THQ and HI values, it will suffice to conclude that these plants are more or less considered safe for human consumption except from Cr in LH whose THQ and HI values signal potential health risk.

Keywords: anti-diabetes. trace elements. risk assessment. estimated daily intake. target hazard quotient.

Author α σ: Department of Pure and Applied Chemistry, Adamawa State University, Mubi, Nigeria.

  1. INTRODUCTION

Plants are nature-based pharmaceutical laboratory containing active ingredients of great medicinal importance. They are often utilized locally in complementary medicine, with at least 80% of the world population especially in the developing economy exploring its benefits in the primary healthcare services [1]. The renaissance of herbal-based remedy was estimated to account for approximately 25% of pharmaceutical drugs and nearly 60% of anticancer drugs [2, 3]. These unquantifiable benefits has generated entrepreneurship in family-based health care systems, busting the herbal-based rural market and increasing the global trade volume of plant-based pharmaceutical products and other plant-based dietary supplements [4]. These development is expected to expand the global market for plant-based health products to about $60 billion annually, projected to be driven in part by consumer preference for nature-based materials that are sustainable and affordable [1].

In Nigeria today, one common disease that present it ugly face in both the rural and urban settings is DM which according to the International diabetes federation (IDF), recorded a prevalence rate of 3.9% for Nigeria [5] and projected to take the 7th position in global dead related diseases by 2030 [6-8]. Diabetes mellitus and its related complications is estimated to reach $592 million by 2035, going at a global prevalence rate of 10.1% and is projected to push the global cost of  interventions/treatments to about $490 billion by 2030 [5,10]. These scary statistic is projected to grow exponentially considering the poor implementations of government healthcare intervention policies and the corresponding high cost of orthodox medicine [1]. These systemic decay, forces a shift and emphases into plant-based therapy for the treatment and management of DM and its related complications in Nigeria. This however, leads to massive explorations of plants species with active biological components that can support and potentiate insulin metabolism. Thus, the hypoglycemic properties of medicinal plants, in addition to being actively supported by some phytochemicals are also potentiated by some essential micro and macro elements housed within the plants [11, 12].

Using instrumental neutron activation analysis (INAA), we reported in our previous study the presence of some macro elements, micro elements, trace element and some natural radioactive elements in anti-diabetic medicinal plants commonly consumed in Adamawa state, Nigeria [13,14].  And further bring into fore, the elemental bioaccumulation trends in relation to the soil-plant interactions and relates same to the physiochemistry of the elements towards insulin metabolism [15]. The bioavailability of the elements based on the elemental content preponderance was further developed and presented based on elemental hierarchal decision tree to further provide guides on the associated risk that may arise from a particular plant species or plant tissue in the treatment and management of DM [16]. Despite the fact that traditional-based medicine may have fared well within the ambit of Nigeria’s home-grown Medicare, the deteriorating condition of the country’s healthcare system visa vice lack of standards in herbal-based remedies remains a potential risk requiring serious attention.

Though, the following elements Ca, Mg, Co, Cr, Mn; Zn, and V, found in the anti-diabetic plants were reported to play a bioactive role in potentiating insulin metabolism as presented in our previous studies [13, 14], the complexity and physiochemical interactions of the elements with the biological systems in relations to the degree/or durations of exposure could introduce certain degree of doubt as regards to their safety. Thus, it’s imperative that medicinal plants use in herbal preparations for human consumption are filtered through quality-health standards checklist. Such exercises will improve consumer confidence and boost the competitiveness of the market. To support the rising popularity of herbal-based remedies in the primary healthcare services for the management of DM and its complications, human health risk assessment of some insulin supporting trace elements (Fe,  Co, Cr, Mn; Zn, and V) found in the anti-diabetic medicinal plants commonly consumed in Adamawa state, Nigeria is conducted and presented in this study. The study is narrowed down to investigate the long time dietary exposure of  the above mentioned insulin supporting elements that may arise from the consumption of these medicinal plants. Due to the ubiquitous nature of the essential elements, it’s often difficult to present a clear picture and establish a balance between its essentiality and toxicity in risk assessments processes. However, this study is conducted bearing in mind this extreme variations with the view to narrow down the variations to a level were the dietary intake of the anti-diabetic plants presents a likelihood of safety or caution in situations where potential risk may suffice.

  1. MATERIALS AND METHODS

2.1  Sampling and Sample Preparations

The following anti-diabetic plants commonly consumed in Adamawa State, Nigeria are used in this study: Terminalia avicennioides (TA), Hymenocardia acida (HA), Leptadenia hastate (LH), Balamites aegyptiacae (BA), Ageratum conyzoide (AC), Sclerocarya birrea (SB), Anogeissus leiocarpus (AL), Jatropha gossypiifolia (JG), Daniellia oliveri (DO), and Sarcocephalus latifolius (SL). The plants species are collected from Mubi North, Mubi South and Maiha Local Government Areas of Adamawa State, Nigeria. The dried powdered samples of the plants were respectively heat-sealed and processed following the same methods adapted in our previous work [13].

2.2  Elemental Analysis of the Anti-diabetic Medicinal Plants using INAA 

The elemental analysis was conducted using the Nigerian Research Reactor-1 (NIRR-1) facility at the center for energy research and training ABU Zaria. The following reference material SRM NIST-1547 (Peach leaves), and NIST- 1515 (Apple Leaves), were used for quality control test and quantitative analyses. Following the various irradiation regime, the retrieved irradiated samples were then collected for the identification of various elements using gamma ray spectrum analysis software (WINSPAN 2004) [13].

2.3  Health Risk Characterization

For the health risk assessments, the average estimated daily intake (EDI) of the elements was obtained by drawing out a relationship between the metals concentrations in the plants, the average consumption of herbal remedy in Nigeria with the respective body weight using the USEPA recommended procedure described in equation 1 [17,18].

                   

Where, EDI is the average daily intake (mg/kg body weight/day); C is the concentration of the elements in the medicinal plant; FIR is the daily consumption rate for herbal medicines consumed by the people. Though, the estimation of the exact amount of each herb used traditionally varied from species to species, as well as dosage and by practitioners, an arbitrary value based upon daily consumption of 3 g were thus considered in this study. The WAB is the body weight (kg); set at 60 for an average adult.

Furthermore, target hazard quotient (THQ) as described in equation 2 was used to determine the human health risk posed by the long-time exposure to the elements following the consumption of the herbal medicines

         )

Where, C is the concentration of the elements in the medicinal plants (mg/kg); FIR is the medicinal plant consumption rate for the respective anti-diabetic plants. EF is the exposure frequency (365 days/year); ED is the exposure duration (70 years); BW is the body weight in kg; and AT is the average time for non-carcinogens (365 days/year × exposure durations). For the study, the oral reference doses (RfDs) of 0.007, 0.009, 1.5, 0.03, 0.30 and 0.014 mg/kg/day were adopted for Fe, V, Cr, Co, Zn, and Mn respectively [19-22]. The description hypothesis a THQ less than 1 to signify no associated risk, meaning the exposed population is unlikely to experience any adverse health hazard. However, if the THQ is equal to or greater than 1, then there is a potential health risk associated [22], thus, calls for concern and interventions.

The health index (HI), expressed as the sum of the hazard quotients THQ  as described in equation 3 is used in this study to describe the cumulative effect posed by the combination of the individual metal presents in the medicinal plants. Thus, the greater the value of HI, the greater the level of concern.  [17, 18].

  1. RESULTS AND DISCUSSION

4.1  Concentrations of insulin supporting elements in the anti-diabetic plants

The average mean concentration of the insulin supporting trace elements Mn, Fe, Co, Cr. Zn and V in the anti-diabetic medicinal plants are presented in Fig 1-3. From the result in Fig.1, the highest concentrations of Mn (808.53±5.00 mg/kg) was found in HA, while the least concentration is recorded in the extract of AL (36.43±0.20 mg/kg).  The concentrations follows the ranking HA>AC>DO>TA>JG>LH>SB> BA>SL>AL respectively. The concentration of Mn points directly to its essentiality as a macro elements, a very important insulin supporting elements, a known activator of gluconeogenic enzyme, known also to modulate glucose transport across cell membranes and improve its tolerance under conditions of dietary stress, [23,24].  The availability of Fe content in the respective medicinal plants shows AC containing the highest concentration (1728.33±67.67 mg/kg), while the least concentration (167.33±38.68 mg/kg) was recorded in the extract of HA. The order of availability based on the concentrations follows the ranking AC>BA>JG>LH>SL>AL>TA>SB> DO>HA respectively. Iron is necessary for red blood cell formation and required for transport of oxygen throughout the body and very important for brain function. Apart from being an essential component of hemoglobin, Fe facilitated the oxidation of carbohydrates, protein and fat to control body weight; needed in the reduction of obesity, a component of DM [25]. The uptake of Fe is physiologically stimulated to allow the metallation of enzymes and electron carriers required for oxidative metabolism [26].

Fig. 1:  Average Mean Concentration of Manganese (Mn) and Iron (Fe) in the Anti-diabetic Medicinal Plants. The results are presented as Mean± SD of three replicate analysis

Further analysis of the respective plants species for Co shows higher concentrations of 17.10±2.37 mg kg in the extract of SL follows by 12.06±2.33 mg/kg in JG and 9.43±1.37 mg/kg in SB respectively.  Based on the results in Fig 2, the concentrations of Co was found to follow the ranking, SL>JG>SB>AC>AL>TA>BA>HA>LH respectively.  Cobalt was reported to possess a glycemia-lowering effect, lowering glucose synthesis and reciprocally increase its cellular uptake. Such cobalt metabolic action were also reported to enhanced the expression of glucose transporter 1 (GLUT1) and inhibition of gluconeogenesis [27, 28]. In addition to the glycemia-lowering effect, Co was also implicated in the observed decrease in lipid peroxidation in diabetic rats [29]. Furthermore, with the exception of AL and BS whose concentrations falls below the detection levels (BDL), the concentration of Cr in the medicinal plants as presented in Fig.2 shows LH containing the highest concentrations (172.67±18.33 mg/kg), while the least values was observed in TA (0.07±0.03 mg/kg). Based on bioavailability, the concentrations of the element in the respective plants species falls in this order, LH>JG>HA>AC>SL>BA>DO>TA. Studies have shown that Cr is an important cofactor that regulate and potentiates the action of insulin, facilitate the cellular uptake of glucose and in the process facilitate in lowing the levels of fasting sugar and restoring glucose tolerance [30, 31]. Similarly, poor Cr status has being single out as a factor contributing to the incidence of impaired glucose tolerance and type II diabetes [32].

Fig. 2:  Average Mean Concentration of Cobalt (Co) and Chromium (Cr) in the Anti-diabetic Medicinal Plants. The results are presented as Mean± SD of three replicate analysis

Zinc is another important insulin actor, activates insulin's secretion in the B-cell and improves the sensitivity of insulin in the management of DM [32, 33]. A necessary cofactor required for the activation of intracellular enzymes needed for glucose metabolism [34, 35]. It has a biphasic effect in that it is required for insulin storage and cellular binding, further reported to mediate glycolysis by influencing the activity of the enzymes, glyceraldehyde-3-phosphate dehydrogenase [34, 35]. The reduction in the intracellular levels of Zn was observed to affects the ability of the islet cell to produce and secrete insulin [33]. It could be observed in Fig.3 that the concentrations of Zn in the extracts of SL and DO are below the detection (BDL) limits. For this element, the highest concentrations of 48.66±4.00 mg/kg was found in the extract of BA and the least in TA (7.10±1.73 mg/kg). The metal contents in the respective plants species falls in this order, BA>AC>SB>JG>LH>HA>AL>TA respectively. Vanadium on the other hand was found to be distributed in all the plants species. As presented in the figure, the highest concentration of V is in SL (13.47±0.20 mg/kg) and the least value in SB (0.36±0.07 mg/kg). Vanadium is multiphasic in that it’s participate in fueling glucose oxidation, glycogen synthesis, carbohydrate metabolism, glycolysis and also serve as a carrier for glucose. Facilitate the upregulation of the insulin receptor and foster the inhibition of hepatic gluconeogenesis [36-38]. In this study, the concentrations of V in the respective plants species were observed to follow the ranking SL>AC>JG>AL>BA>DO>TA>LH>HA>SB.

Fig. 3: Average Mean Concentration of Zinc (Zn) and Vanadium (V) in the Anti-diabetic Medicinal Plants. The results are presented as Mean± SD of three replicate analysis

4.4  Estimated daily intake (EDI)

The anti-diabetic plants investigated in this study as presented in Table 1, contains an appreciable amount of Mn which further translates into an estimated daily intake (EDI) greater than its corresponding RfD value. The RfD often used for the assessment of non-carcinogenic health risk is a reference oral dose values set as an estimate for the tolerable daily intake of metals that will pose no health risk during a lifetime [11, 39]. The EDI of Mn was found to be above the RfD of 0.014 mg/kg/day. The highest EDI was found in HA (40.43 mg/kg/day) and the least in AL (1.82 mg/kg/day). Though, these values are observed to be of concern having exceeded the RfD values, dietary studies have demonstrated that daily intake of high doses of Mn can be safely tolerated by healthy individual [40,41]. Thus, it will suffice to say that the EDI values recorded in this study will not necessary translate into toxic levels. This was accredited to the homeostatic control of Mn retention and excretion processes [41]. These mechanism enabled the human body to handle substantial variations in dietary Mn on a daily basis with little or no risk of overload [41, 42]. However, when administering these medicinal plants, factors such as health status should be considered.

The estimated daily intake for Fe in this study as presented in the table shows AC containing the highest EDI of 86.42 mg/kg/day and the least in HA (8.37 mg/kg/day). These values as indicated in the table are all above the RfD for Fe (0.007 mg/kg/day), indicating potential health related implication following the ingestion of Fe via the consumption of these medicinal plants. Physiologically, Fe was observed to exert a causal role in diabetes pathogenesis mediated both by β-cell failure and insulin resistance. [26, 43]. Dietary Fe in excess to the range required for normal erythropoiesis and metabolic function has a direct effect on the secretion of insulin and insulin sensitivity. Such overload could also leads to the activation of stress pathways, mediate adipocyte iron-sensing role and mitochondrial dysfunction [26, 43]. However, the multifactorial role of Fe towards weight regulation are possible route in which excess Fe intake regulates the likelihood of Fe induce toxicity. Essential for lipolysis of adipocytes, thus slows down obesity related biology [44]. High dietary Fe are channel to augment fatty acid oxidation and stimulates lipogenesis [45]. Therefore, the ability of Fe to regulate adiponectin secretion further suggests its essentiality to coordinate metabolism by regulating other hormones important to fuel and energy homeostasis [26]

The EDI for Co in most of the anti-diabetic plants investigated in this study falls below the RfD levels (0.03 mg/kg/day) except for JG (0.603 mg/kg/day), SL (0.855 mg/kg/day) and SB (0.472 mg/kg/day). The results thus suggest that the consumption of AC, AL, BA, DO, HA, LH and TA poised no health risk. However, potential health risk could be associated with the consumption of JG, SL and BS respectively. Though, Co was reported to have low oral toxicity [46], exposure above the safety limits are implicated to number of health related cases such as gastrointestinal complications, liver injury, and allergic dermatitis [47]. Despite the fact that the EDI recorded in this study appeared on a slightly lower sides, caution has to be applied especially in patients with other health complications before administering herbal remedy with high content of cobalt.

The highest EDI of Chromium (8.66 mg/kg/day) was found in LH and the least in TA (0.003 mg/kg/day). From the results it was observed that all the EDI recorded in the respective anti-diabetic plants falls below the RfD (1.5 mg/kg/day) levels except in LH (8.66 mg/kg/day). The EDI values for Cr recorded in the following plants AC, AL, BA, DO, HA, and TA posed no health risk, however, caution should be applied for Cr toxicity when consuming LH as a remedy for diabetes. Chromium toxicity is associated to liver and kidney damage. Other toxic effects includes skin irritation/nose irritation, and lung cancer [48] 

From the results in the table, the EDI for Zn in all the respective anti-diabetic plants were found to be above the RfD (0.30 mg/kg/day). The results show the highest EDI of 2.43 mg/kg/day in BA, while the least of 0.35 mg/kg/day was found in TA. Though, Zn plays a vital role in supporting insulin metabolism, excess amount above the RfD levels come with a price. Zinc poisoning as a result of exposure above the RfD levels were reported to induce complications such as nausea, vomiting, diarrhea, fever and lethargy. Physiological, high levels of Zn above the tolerable limits were reported to have the propensity to interfere and in some cases alter the metabolic chemistry of other trace elements [49, 50].

Furthermore, it could be noted that the highest EDI for V was found in the extract of SL (0.673 mg/kg/day), while the lowest EDI of 0.018 mg/kg/day was observed in the extract of SB. Based on the RfD of 0.009 set for V, it is obvious that the EDI recorded for the respective anti-diabetic plants exceeded the RfD levels. Though, the difference between the EDI level and the RfD is minimal, the difference however, suggest that caution should be applied during the consumption of these plants. Oral consumption of V at a very high dose were reported to induce gastrointestinal disturbances in humans. Other complications reported includes kidney lesions, nervous disturbances, neurasthenic or vegetative symptoms [51].

Table 1:  Estimated Daily Intake in mg/kg/d for Mn, Fe, Co, Cr, Zn and V in Anti-diabetic Medicinal Plants Commonly Consumed in Nigeria

Elements

AC

AL

BA

DO

HA

JG

LH

SL

SB

TA

Mn

8.79

1.82

2.55

7.15

40.43

4.00

3.61

2.18

3.39

4.36

Fe

86.42

14.76

37.80

9.33

8.37

35.53

28.18

21.90

12.43

13.58

Co

1.15E-02

8.00E-03

5.00E-03

5.00E-03

5.00E-03

6.03E-01

3.00E-03

8.55E-01

4.72E-01

6.50E-03

Cr

1.80E-02

-

6.50E-03

5.00E-03

2.15E-02

6.33E-01

8.63

1.50E-02

-

3.00E-03

Zn

2.17

3.67E-01

2.43

-

5.83E-01

1.02

9.93E-01

-

1.02

3.55E-01

V

3.17E-01

8.80E-02

6.15E-02

5.30E-02

3.00E-02

1.20E-01

3.15E-02

6.73E-01

1.80E-02

4.65E-02

The dose makes the poison is often implied to all chemicals [41], therefore, the ubiquitous nature of the respective elements discussed above has to be factored into the equation in order to draw a line between its essentiality and potential risk. Thus, the underlining EDI however, important towards seating a limit to its exposure does not necessary implies toxicity, as individuals may experience different responses under different conditions, dose and concentrations. As mentioned above, the EDI assessments processes relate the consumption data with the concentrations of the respective elements and its relationship to the bodyweight. These assessment processes, though significant towards understanding the likelihood of toxic related effect associated with the consumption of these medicinal plants, however, falls short of providing the possible health risk effects that may occur over a lifetime relative to the most appropriate limit value. Therefore, to get a realistic health risk picture, the risk characterization processes is made by comparing it with health-based statistical probability. The statistical probability is therefore expressed as a function of the quantified level of concern in the form of THQ, a process developed to estimate the potential health risks associated with long-term exposure to chemical pollutants [20, 21, 52].

4.5  Health risk Assessment

The risk assessment processes involved a concise analysis of the likelihood of harm that may arise following the exposure/or consumption of hazardous materials. The THQ was computed to investigate the potential risk posed by these elements following the consumption of these anti-diabetic plants. The THQs of the six elements analyzed from the ten anti-diabetic medicinal plants are presented in Table 2. From the results presented in the table, the THQ for the   individual elements for the individual anti-diabetic plants were observed to be <1, which is considered safe for human consumption. However, not all the anti-diabetic plants shows a THQ value <1 for Cr. A THQ >1 for Cr was observed in LH (12.95). These values is expected as this particular specie (LH) recorded an EDI above the RfD levels for Cr. Thus, this particular species is therefore consider not entirely safe for human consumption. Considering the potential risk to human health, the cumulative effects of the individual metals for a particular species shows a HI values <1 in most of the plant species, except in LH (13.30) and JG (1.36). Its therefore assumed that the magnitude of the effect which is directly proportional to the sum of the multiple metal exposure point towards LH and JG as potential health risk to human and thus, raise the level of concern to their consumptions

From the THQ and HI values derived for the individual elements in most of the anti-diabetic plants and the scenario discussed above to buttress their insulin supporting properties, it will suffice to conclude that these plants are more or less considered safe for human consumption. However, factors such as patience health history should be factored before administering these herbal remedies. In some rare occasions, a combination of more than one medicinal plants such as in concoction could increase the THQ >1, thus, increasing the likelihood for possible human risk. Therefore, carrying out THQ and HI to ascertain the potential human risk that may arise from the consumption of concoctions should be investigated.

Table 2:  Target hazard quotient (THQ) for Mn, Fe, Co, Cr, Zn and V in Anti-diabetic Medicinal Plants Commonly Consumed in Nigeria

Elements

AC

AL

BA

DO

HA

JG

LH

SL

SB

TA

Mn

1.23E-01

2.55E-02

3.57E-02

1.00E-01

5.66E-01

5.60E-02

5.06E-02

3.05E-02

4.74E-02

6.10E-02

Fe

6.05E-01

1.03E-01

2.65E-01

6.53E-02

5.86E-02

2.49E-01

1.97E-01

1.53E-01

8.70E-02

9.51E-02

Co

3.45E-04

2.40E-05

1.50E-05

1.50E-05

1.50E-05

1.81E-03

9.00E-06

2.57E-03

1.41E-03

1.95E-05

Cr

2.70E-02

-

9.75E-03

7.50E-03

3.23E-02

9.50E-01

12.95

2.25E-02

-

4.50E-03

Zn

2.17E-01

3.67E-02

2.43E-01

-

5.83E-02

1.02E-01

9.93E-02

-

1.02E-01

3.55E-02

V

2.85E-03

7.92E-04

5.54E-04

4.77E-04

2.70E-04

1.08E-03

2.84E-04

6.06E-03

1.62E-04

4.19E-04

HI

9.75E-01

1.66E-01

5.54E-01

1.73E-01

7.15E-01

1.36

13.30

2.15E-01

2.38E-01

1.97E-01

V.    CONCLUSION

The ubiquitous nature of the respective elements as analyzed in this study underscore their essentiality in supporting insulin metabolism against the possible risk. In the study, the underlying EDI shows a level greater than their corresponding RfD in most of the plant species. Iron was observed to show the highest EDI above the RfD, followed by Mn, Zn and finally V. Though, the EDI having exceeded the RfD levels as observed in the study, however important towards seating a limit to its exposure does not necessarily implies toxicity. This observation as demonstrated in the results shows the   individual elements for the individual anti-diabetic plants having THQ and HI value <1 safe for human consumption. The results further shows a variation in the LH, the species was observed to have a THQ values >1 for Cr and a very high HI index >1 in the same species. Thus, suggest that this particular species is not entirely safe for human consumption.

REFERENCE

  1. Mafmisebi TE, Oguntade AE, Ajibefun IA, Mafmisebi OE, Ikuemonisan ES. The Expanding Market for Herbal, Medicinal and Aromatic Plants In Nigeria and the International Scene. Med Aromat Plants, 2013; 2:144. doi: 10.4172/2167-0412.1000144
  2. Brower V. Back to nature: extinction of medicinal plants threatens drug discovery. J Natl Cancer Inst, 2008; 100: 838–9. doi: 10.1093/jnci/djn199 PMID: 18544733
  3. Newman DJ and Cragg GM. Natural products as sources of new drugs over the 30 years from 1981 to 2010. J Nat Prod, 2012; 75: 311–35. doi: 10.1021/np200906s PMID: 22316239
  4. Abdullah R, Diaz LN, Wesseling S, Rietjens IMCM. Risk assessment of plant food supplements and other herbal products containing aristolochic acids using the margin of exposure (MOE) approach, Food Additives & Contaminants:Part A, 2017; 34(2): 135-144,
  5. International Diabetes Federation (IDF). Diabetes Atlas. 2010; (4th edn), IDF, Brussels, Belgium
  6. Roglic G, Unwin N, Bennett PH, Mathers C, Tuomilehto J, et al. The burden of mortality attributable to diabetes: realistic estimates for the year 2000. Diabetes Care, 2005; 28: 2130-2135.
  7. King H, Gruber W, Lander T. Implementing national diabetes programmes- Report of a WHO meeting. Geneva: World Health Organization. International Diabetes Federation (IDF), 1995; (5th edn) Diabetes Atlas.
  8. Oguejiofor O, Odenigbo C, Onwukwe C. Diabetes in Nigeria: Impact, Challenges, Future Directions. Endocrinol Metab Synd, 2014; 3 (2):100-130.
  9. International Diabetes Federation, The IDF Diabetes Atlas, International Diabetes Federation, Brussels, Belgium, 6th edition, 2013.
  10. Siddiqui K, Bawazeer N, Salini Scaria Joy .Variation in Macro and Trace Elements in Progression of Type 2 Diabetes. The Scientific World Journal, 2014; 2014:1-9. https:// dx.doi.org/10.1155/2014/461591
  11. Arika WM, Ogola PE, Nyamai DW, Mawia AM, Wambua FK, Kiboi NG, et al. Mineral elements content of selected Kenyan anti-diabetic medicinal plants. Advanced Techniques in Biology & Medicine, 2016; 4(1): 2-5.
  12. Ngugi P, Njagi J, Kibiti C, Maina D, Ngeranwa J, et al. Trace elements content of selected Kenyan anti-diabetic medicinal plants. Int J Curr Pharm Res, 2012; 4: 39-42.
  13. Magili TS and Bwatanglang IB. Determination of Macro and Micro Elements in Some
    Selected Anti-diabetic Medicinal Plants in Adamawa State, Nigeria Using Instrumental Neutron Analysis. WWJMRD, 2018a; 4(6): 181-190.
  14. Magili TS and Bwatanglang IB. Determination of Natural Radioactive and Trace elements in Some Selected Anti-diabetic Medicinal Plants in Adamawa State, Nigeria Using Instrumental Neutron Analysis. WWJMRD 2018b; 4(7): 55-66.
  15. Magili TS and Bwatanglang IB. Plant-Soil Interaction and Bioaccumulation of Elements in Anti-diabetic Medicinal Plants Commonly Used in Adamawa State, Nigeria. WWJMRD 2018c; 4(7): 112-128.
  16. Magili TS and Bwatanglang IB. Bioaccumulation Trend Analysis of Insulin Supporting Elements in Anti-diabetic Medicinal Plants and Hierarchal Presentation Based on Decision Tree. IJGHC, Sec. B; Vol.7, No.4, (2018d) 401-418.
  17. USEPA U. Exposure factors handbook. Office of Research and Development, 1997 Washington
  18. Kohzadi S,  Shahmoradi B, Ghaderi E, Loqmani H, Maleki A. Concentration, Source, and Potential Human Health Risk of Heavy Metals in the Commonly Consumed Medicinal Plants. Biological Trace Element Research, 2018:https://doi.org/10.1007/s12011-018-1357-3
  19. Liu X, Song Q, Tang Y, Li W, Xu J, Wu J, Wang F, Brookes, P. C. Human health risk assessment of heavy metals in soil–vegetable system: A multi-medium analysis. Science of The Total Environment, 2013; 463–464, 530–540.
  20. U.S. Environmental Protection Agency (USEPA). A Review of the Reference Dose and Reference concentration Processes, 2002. EPA/630/p-02/002F, Washington, DC: U.S. Environmental Protection Agency.
  21. U.S. Environmental Protection Agency (USEPA). Regional Screening Levels (RSLs) – Generic Tables, 2016, Washington, DC: U.S.
  22. Sultana MS, Rana S, Yamazaki S, Aono T and Yoshida S. Health risk assessment for carcinogenic and noncarcinogenic heavy metal exposures from vegetables and fruits of Bangladesh. Cogent Environmental Science, (2017),\; 3: 1291107
  23. Hurley LS and Keen CL. Manganese In: Mertz W. (Ed). Trace Elements in human and Animal Nutrition, 5th Edn. Academic Press, Orlodo, 1987.
  24. Lee SH, Jouihan HA, Cooksey RC, Jones D, Kim HJ, Winge DR, McClain DA. Manganese supplementation protects against diet-induced diabetes in wild type mice by enhancing insulin secretion. Endocrinolog, 2013; 154(3):1029-1038.
  25. Ashraf M, Hayat M, Munitaz F. A Study on elemental Contents of Medicinally important species of Artemisia L. (Asterceae) found in Pakistan. Journal of Medicinal Plant Res, 2010; (4):2256-2263
  26. Simcox A and McClain DA. Iron and Diabetes Risk. Cell Metab, 2013; 5; 17(3): 329–341.
  27. Saker F, Ybarra J, Leahy P, Hanson RW, Kalhan SC, Ismail-Beigi F. “Glycemia- lowering effect of cobalt chloride in the diabetic rat: role of decreased gluconeogenesis,” American Journal of Physiology—Endocrinology and Metabolism, 1998; 274(6): E984–E991, 1998
  28. Anjum A, Yousaf M, Zuber M, Ahmad HB,  Zahoor AF, Khan ZI. Comparative study on calcium, magnesium and cobalt in diabetic and non-diabetic patients (males) in Punjab, Pakistan African Journal of Biotechnology, 2012; 11(28):7258-7262.
  29. Yıldırım O and Buyukbingol Z. Effect of cobalt on the ¨oxidative status in heart and aorta of streptozotocin-induced diabetic rats. Cell Biochemistry and Function, 2003; 21 (1): 27–33.
  30. Khan A, Bryden NA, Polasky MN, Anderson RA. Insulin- potentiating factor and chromium content of selected spices. Biol. Trace Elem. Res, 1990; 24:183-188
  31. Abraham AS, Brooks BA, Eylath U. The effects of chromium supplementation on serum glucose and lipids in patients with and without non-insulin dependent diabetes. Metabolism, 1992; 41:768-771.
  32. Kinlaw WA, McClaw L. Abnormal Zinc Metabolism in type II diabetes Mellitus. Am J. Med, 1983; 75 (2):273-237.
  33. Emdin SO, Dodson GG, Cutfield JM, Cutfield SM. Role of zinc in insulin biosynthesis. Some possible zinc-insulin interactions in the pancreatic B-cell. Diabetologia, 1980; 9(3):174-182.
  34. Tapiero H, Tew KD. Trace elements in human physiology and pathology: zinc and metallothioneins. Biomed Pharmacother, 2003; 57: 399-411.
  35. Watts DL. Trace elements and glucose disorders. Trace Element Inc Newsletter, 1999; 11(2)
  36. Orvig C, Tompson KH, Battell M, McNeill JH. Vanadium compounds as insulin mimics,” Metal Ions in Biological Systems, 1995; 31(1): 575–594.
  37. Poucheret P, Verma S, Grynpas MD, McNeill JH. Vanadium and diabetes. Molecular and Cellular Biochemistry, 1998; 188(1-2): 73–80, 1998.
  38. Cam MC, Brownsey RW, McNeill JH. Mechanisms of vanadium action: insulin-mimetic or insulin-enhancing agent. Canadian Journal of Physiology and Pharmacology, 2000; 78(10): 829–847, 2000.
  39. Al-Awadi FM, Anim JT, Srikumar TS. Possible role of trace elements in the hypoglycemic effect of plants extract in diabetic rats, The Journal of Trace Elements in Experimental Medicine, 2004; 1731–1744.
  40. Finley JW. Does environmental exposure to manganese pose a health risk to healthy adults? Nutr Rev, 2004; 62 : 148-53
  41. Santamaria AB. Manganese exposure, essentiality & toxicity. Indian J Med Res, 2008; 128: 484-500
  42. Finley JW, Penland JG, Pettit RE, Davis CD. Dietary manganese intake and type of lipid do not affect clinical or neuropsychological measures in healthy young women. J Nutr 2003; 133: 2849-56
  43. Wilson JG, Lindquist JH, Grambow SC, Crook ED, Maher JF. Potential role of increased iron stores in diabetes. Am J Med Sci, 2003; 325: 332-339.
  44. Rumberger JM, Peters T Jr, Burrington C, Green A. Transferrin and iron contribute to the lipolytic effect of serum in isolated adipocytes. Diabetes, 2004; 53:2535–2541
  45. Baquer NZ, Hothersall JS, Sochor M, McLean P. Bio-inorganic regulation of pathways of carbohydrate and lipid metabolism. 1. Effect of iron and manganese on the enzyme profile of pathways of carbohydrate metabolism in adipose tissue during development. Enzyme, 1982;27:61–68
  46. Hokin, B., et al.. Analysis of the cobalt content in Australian foods. Asia pacific journal of clinical nutrition, 2004; 13: 284–288.
  47. Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Cobalt. Public Health Service, U.S. Department of Health and Human Services, Atlanta, GA. 1992.
  48. Khan, SA, Khan L, Hussaini I, Marwat KB, Ashtray N. Profile of Heavy Metals in selected Medicinal Plants. Pakistan Journal of Weed Science Research, 2008; 14 (1-2):101 -110
  49. Fischer PWF, Girourx A, L'Abbe MR. Effect of zinc supplementation
    on copper status in adult man. Am J Clin Nutr, 1984;40:743–6
  50. Obi E, Akunyili DN, Ekpo B, Orisakwe OE. Heavy metal hazards of Nigerian herbal remedies. Science of the Total Environment, 2006; 369 (2006) 35–41
  51. Waters, M.D. Toxicology of vanadium. In: Goyer, R.A. & Mehlman, M.A., ed. Advances
    in modern toxicology. Vol. 2. Toxicology of trace elements. New York, Wiley, 1977, pp.
    147-189
  52. Salama AK. Health risk assessment of heavy metals content in cocoa and chocolate products sold in Saudi Arabia, Toxin Reviews, 2018; DOI:10.1080/15569543.2018.1471090.



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