Consumption of Raw Herbal Medicines Is Associated with Major Public Health Risks amongst Ugandans

Abstract

Background. Community consumption of herbal plants in developing countries is a common practice, however, scarcity of information on their physiochemical composition is a major public health concern. In Uganda, Vernonia amygdalina is of interest in rural communities due to its therapeutical action on both bacterial and protozoal parasites, however no studies have been conducted to assess the heavy metal concentrations in traditional plants used in alternative medicine. The aim of the study was to establish concentrations of heavy metals in Vernonia amygdalina, model the estimated daily intake (EDI), and assess both the non-cancer-related health risk using the target hazard quotient (THQ), and the risk related to cancer through the incremental lifetime cancer risk (ILCR) for the Ugandan population. Methods. Leaves of Vernonia amygdalina were collected from 20 georeferenced villages and processed into powder in the laboratory using standard methods. These were then analyzed in the laboratory using an atomic absorption spectrometer for lead (Pb), chromium (Cr), copper (Cu), zinc (Zn), cobalt (Co), iron (Fe), cadmium (Cd), and nickel (Ni). Concentrations were compared against the World Health Organization (WHO) limits. The EDI, THQ, and ILCR were modelled and significance was measured at 95% confidence. Results. The study showed that mean ± SEM concentrations of heavy metals were highest in the order of Cr, 121.8 ± 4.291 ppm > Ni, 84.09 ± 2.725 ppm > Zn, 53.87 ± 2.277 ppm > Pb, 40.61 ± 3.891 ppm > Cu, 28.75 ± 2.202 ppm > Fe, 14.15 ± 0.7271 ppm > Co, 7.923 ± 0.7674 ppm > Cd, 0.1163 ± 0.005714 ppm. Concentrations of Pb, Cr, Zn, Co, and Ni were significantly higher than the WHO limits. The EDI was significantly higher in children than in adults, demonstrating an increased risk of toxicity in children. The THQ and ILCR were over 1000 times higher in all Ugandans, demonstrating the undesirable health risks following oral consumption of Vernonia amygdalina due to very high Cr and Ni toxicities, respectively. Conclusion. Consumption of raw Vernonia amygdalina was associated with a high carcinogenic risk, demonstrating a need to enact policies to promote physiochemical screening of herbal medicines used in developing countries against toxic compounds.

An analysis of heavy metals contamination and estimating the daily intakes of vegetables from Uganda

“…The findings here, preliminary as they may be, when put together with a preponderance of evidence pointing to serious and sustained consumption of contaminated foods in Uganda, 3,82,90,[100][101][102][103][104] justify a policy revisit by the responsible regulatory authorities in Uganda, i.e. National Drug Authority (NDA), Ministry of Health, and Ministry of Agriculture Animal Industry and Fisheries (MAAIF), Uganda National Environmental Authority (NEMA), to promote food safety and trade in vegetables.…”

“…41 These metals in plants for human consumption raise public health concerns since the disruption of human physiology outweighs any dietary advantages associated with the vegetables. 3,11,12 Additionally, very high concentrations above WHO limits would predispose the community to neurological diseases. 51,52,77,78 In the southern part of Africa, some heavy metals were above the maximum allowable concentrations in vegetables.…”

“…In Uganda-the subject of this study, heavy metals have been identified in milk, beef, drinking water, and herbal medicines in southwestern Uganda. [1][2][3] Pb concentrations of between 4 and 18 ppm have been recorded in amaranthus within Uganda. 4 Vegetables grown along Lake Victoria (Uganda) were associated with high cadmium (Cd) and lead (Pb) at concentrations of 0,08-0.76 ppm and 0.003-5.06 ppm respectively above World Health Organization limits.…”

Heavy Metals and Health Risks Associated with Consumption of Herbal Plants Sold in a Major Urban Market in Southwest, Nigeria

“… 29 , 30 Chromium has been detected in many studies to be highly toxic. 19 , 31 , 32 , 18 Chromium toxicity leads to allergic responses like urticaria. 33 , 34 If ingested beyond acceptable limits, exposure to Cr could lead to anemia, damage to the male reproductive system, gastrointestinal irritation and heart-related diseases like cardiovascular and respiratory challenges.…”

“…When humans are exposed to moderate concentrations of these elements, either beneficial or toxic effects can occur, depending on their composition in the substance consumed. 32 The aim of the present study was to assess the level of exposure, toxicity and health risk associated with the consumption of herbal plants bought from Ado Ekiti urban market for consumption by adults and children in Ado Ekiti, southwest Nigeria.…”