Evaluation of Carcinogenic and Non-Carcinogenic Risks of Heavy Metals in Selected Medicinal Plants

Figures & data

Table 1. Limits of detection (LOD) and recoveries of metals in acacia abyssinica, Carissa spinarum, Dodonaea angustifolia, and Euclea racemose.

% (Recovery ±RSD)
Metal	LOD	D. angustifolia	C. spinarum	E. racemose	A. abyssinica
Zn	0.017	98.5 ± 1.3	97.2 ± 3.1	96.4 ± 5.3	99.5 ± 1.5
Cu	0.137	81.1 ± 2.5	82.8 ± 5.3	83.1 ± 3.3	81.6 ± 1.8
Fe	0.293	102 ± 3.5	102 ± 1.5	103 ± 6.2	100 ± 3.2
Pb	0.134	88.3 ± 2.1	89.4 ± 8.2	87.9 ± 3.8	88.6 ± 4.2
Cd	0.038	101 ± 2.9	102 ± 1.6	101 ± 2.6	99.3 ± 2.2
Ni	0.048	83.1 ± 3.8	82.8 ± 3.3	84.5 ± 2.4	83.5 ± 3.4
Mn	0.052	85.4 ± 4.0	83.3 ± 4.2	84.7 ± 1.7	86.3 ± 5.1

Table 2. Concentration (mean ± SD, mg kg⁻¹ dry weight) of essential and toxic metals in acacia abyssinica, Carissa spinarum, Dodonaea angustifolia, and Euclea racemose.

	Concentration of metal (mg kg^−1) dry weight
Metals	Dodonaea angustifolia	Carissa spinarum	Euclea racemose	Acacia abyssinica	WHO (2007)
Cd	0.171 ± 0.05	0.202 ± 0.18	0.292 ± 0.2	0.402 ± 0.05	0.3
Cu	11.7 ± 0.79	8.87 ± 1.13	24.6 ± 1.02	25.3 ± 1.2	40
Pb	3.10 ± 0.31	8.53 ± 0.4	0.771 ± 0.08	4.04 ± 0.3	5
Zn	23.8 ± 1.02	12.3 ± 0.8	11.5 ± 1.64	17.6 ± 1.16	60
Mn	29.2 ± 0.72	41.1 ± 0.97	64.9 ± 1.38	28.3 ± 1.32	500
Ni	4.01 ± 0.3	8.02 ± 0.81	3.84 ± 0.33	4.42 ± 0.52	10
Fe	106 ± 3.9	107 ± 3.5	55.9 ± 2.84	58.1 ± 2.92	450

Table 3. Pearson correlations of metals in acacia abyssinica Carissa spinarum, Dodonaea angustifolia and euclea racemose.

Med. Plant		Fe	Mn	Zn	Cu	Ni	Cd	Pb
Acacia	Fe	1
abyssinica	Mn	0.999	1
	Zn	0.999	0.999	1
	Cu	0.754	0.780	0.750	1
	Ni	0.003	−0.038	0.009	−0.655	1
	Cd	0.274	0.314	0.269	0.839	0.961	1
	Pb	0.186	0.226	0.180	0.786	0.982	0.996	1
Carissa	Fe	1
spinarum	Mn	−0.988	1
	Zn	0.854	−0.923	1
	Cu	−0.985	0.999	−0.931	1
	Ni	0.956	−0.989	0.968	−0.992	1
	Cd	−0.421	0.554	−0.831	0.572	0.667	1
	Pb	−0.987	0.999	−0.926	0.999	0.991	0.560
Dodonaea	Fe	1
angustifolia	Mn	−0.987	1
	Zn	0.989	−0.999	1
	Cu	−0.985	0.999	0.999	1
	Ni	−0.762	0.648	0.661	0.638	1
	Cd	−0.421	0.562	0.547	0.5721	−0.266	1
	Pb	−0.152	−0.009	0.008	−0.021	0.756	0.832	1
Euclea	Fe	1
racemosa	Mn	−0.999	1
	Zn	−0.999	0.999	1
	Cu	0.865	−0.863	0.847	1
	Ni	0.657	−0.659	0.683	0.189	1
	Cd	0.497	−0.495	0.468	0.866	−0.327	1
	Pb	0.999	−0.999	0.999	0.860	0.663	0.490	1

Table 4. Non-cancer risk index of metals in acacia abyssinica, Carissa spinarum, Dodonaea angustifolia, and Euclea racemose.

	D. angustifolia		C. spinarum		E. racemose		A.abyssinica
Metal	ADI	THQ	AID	THQ	ADI	THQ	ADI	THQ
Cd	0.0012	1.2018	0.0006	0.6178	0.0005	0.5338	0.0012	1.2000
Cu	0.0077	0.1923	0.0027	0.0682	0.0036	0.0897	0.0076	0.1892
Fe	0.0179	0.0255	0.0329	0.0469	0.0328	0.0468	0.0172	0.0246
Mn	0.0087	0.0623	0.0126	0.0903	0.009	0.0641	0.02	0.1426
Ni	0.0013	0.0637	0.0025	0.1231	0.0012	0.0615	0.0012	0.0591
Pb	0.0012	0.3516	0.0026	0.7473	0.001	0.2725	0.0002	0.0677
Zn	0.0054	0.0181	0.0038	0.0126	0.0073	0.0244	0.0035	0.0118
Hazard Index		1.9153		1.7062		1.0928		1.695

Table 5. Carcinogenic risks (CR) of Cd and Pb due to medicinal use of acacia abyssinica, Carissa spinarum, Dodonaea angustifolia, and Euclea racemose.

Metal	D. angustifolia	C. spinarum	E. racemose	A. abyssinica
Cd	2.03 × 10^−7	2.35 × 10 − 7	4.61 × 10^−7	4.56 × 10^−7
Pb	7.53 × 10^−9	2.06 × 10 − 8	1.87 × 10^−9	9.71 × 10^−9

Figure 1. Hierarchical cluster analysis of metals in acacia abyssinica Carissa spinarum, Dodonaea angustifolia and euclea racemose.

Figure 2. Hierarchical cluster analysis of acacia abyssinica (AA) Carissa spinarum (CS), Dodonaea angustifolia (DA) and euclea racemose (ER).

Figure 3. Principal component analysis of metals in acacia abyssinica, Carissa spinarum, Dodonaea angustifolia, and Euclea racemose.

Data availability statement

Data will be made available on request.