Heavy metal content and health risk assessment of commonly patronized herbal medicinal preparations from the Kumasi metropolis of Ghana

Abstract

Purpose To address the question of whether users of herbal products (HPs) are exposed to harmful contaminants, we evaluated six HPs mostly patronized in Kumasi for heavy metal contamination and assessed the health risk associated with their use. This study is one of the first safety evaluation studies on finished multiherbal products in the region. Method Three antimalarial, two antidiabetic and one antihypertensive HPs were selected after a mini-survey and coded randomly as HP A-F. The HPs were acid digested for quantitative analysis of heavy metals using Inductively Coupled Plasma Mass Spectrometer. Hg quantification was carried out using cold vapour atomic absorption spectroscopy. Results The cancer risk estimation values for the carcinogenic metals ranged between 1.54 × 10 −9 to 3.73 × 10 −4 and were all within acceptable limits. The non-cancer health risk evaluation revealed that, some of the products pose health risk to consumers. The estimated daily intake (EDI) for As in HPF was 2.48 × 10 −4 mg/kg/day compared to the reference limit of 1.67 × 10 −4 mg/kg/ day. HPF also had high hazard index (HI) of 5.70 (HI >1) in children as compared to 1.68 (HI >1) in adults showing a 3.4 folds increase in the health risk among the former. Conclusion The six polyherbal products exhibited carcinogenic risk within acceptable limits. Although, the non-carcinogenic risk assessment of products HPA to HPE suggests safety, this can only be ascertained after further characterization of their health risks in detailed chronic toxicity studies. The high HI for product HPF suggests health risk for consumers of this product.

Sub-chronic toxicity evaluation of top three commercial herbal antimalarial preparations in the Kumasi metropolis, Ghana

“…This assertion on HPC also correlates well with a clinical trial of the same product which was published at the time this current study was ongoing [34]. On the other hand, the argument for a possible chronic liver toxicity induced by the HPs is supported by the previously identified chemical toxicants in these products [20,35]. Histologic findings from this study, however, support the induction of liver toxicity by the HMPs.…”

“…The induction of GIT lesions by HPB seems to correlate with our recent study where we reported the presence of significantly high levels of Cr above MRL limit in this herbal preparation [20]. Similar morphological changes were observed in the lungs of rats that received HPC with the alveolar showing inflammatory changes dominated by lymphocytes and macrophages and alveolar spaces obscured by debris and chronic inflammatory cells which could be attributed to the heavy metal contaminations previously identified at concentrations above their respective MRL values [20,37].…”

“…The chronic inflammation and possible occurrence of atrophy could explain the significantly low relative kidney weight in HPC(1) [40,41]. The observed foci of chronic inflammation in the present study may be related to the presence of heavy metals (arsenic, chromium and nickel) and pesticides (aldrin and dieldrin) as previously stated and reported in our recent article [20]. This also correlates with previous findings on chromium (VI), [38] arsenic [42], and aldrin [37] toxicities.…”

“…The heart sections of rats given HPB (10) show foci of intensely eosinophilic muscle fibres, haemorrhage with associated amorphous exudates, isolated muscle fibres and scattered intensely congested vessels. This effect may in part be attributable to the high concentration of heavy metals like arsenic in these products [20]. Association of arsenic and inflammatory damage to the vascular system has been reported in literature.…”

“…Regular safety surveillance of these commercial products is also lacking thereby creating data gap and raising public health concerns [19]. In our previous studies, we identified commercially available multiherbal products from the Ghanaian market with high levels of heavy metals and banned pesticide [20,21]. Supplementary Table S1 provides a summary of the ethnomedicinal uses and adverse or toxic effects of some medicinal plants employed in Traditional African Medicine.…”