Case Studies in Chemical and Environmental Engineering (Jun 2024)
Determination of heavy metals contamination, risk prediction and antioxidant properties of anti-malarial herbal mixture sold in Kano state, Nigeria
Abstract
Herbal remedies are alternative option for the treatment, management, and prevention of different disease conditions such as malaria in most African communities due to their easy access and economic advantages. Heavy metals contaminations from the plant ingredients, processing or anthropogenic activities may render the herbal harmful for human consumption. Therefore, risk assessment of contaminating metals and antioxidant activities were determined in Agbo, a popular anti-malarial herbs mixture sold in Kano. The samples were collected from different locations across Kano State and labelled as A, B, C. The concentrations of some human cancer-causing (Cadmium Cd; Lead Pb and Chromium Cr) and some non-cancer-causing metals such as Copper Cu; Nickel, Ni in the sample were evaluated. The antioxidant properties were also evaluated using various assays, which include 2,2-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2) scavenging actions, Metal Chelating, phosphomolybdate test and Reducing power properties of Agbo. Some phytochemicals (Phenolic acids, flavonoids, tannins, saponins and alkaloids) were found to be present. The values predicting the probability of human developing risk of cancer ailment after the ceaseless consumption of the herbal mixtures was found higher than a standard threshold limit (>10−4) established by USEPA. While the non-cancer predicted risk index projected the Cr, Pb and Cd (from sample B) as the leading metal pollutants of the herbal mixtures posing a risk index of more than one (>1), while Ni and Pb (from sample A and C) showed a relative safe quotient. The determined IC50 value for reducing power showed the herbal mixtures exhibiting almost same antioxidant activities with sample C having the highest (IC50 6.32 μg/mL), followed by sample B (IC50 6.36 μg/mL) and sample A (IC50 6.39 μg/mL). This suggests that excess consumption of this mixtures may be generally beneficial health-wise but unsafe due to the heavy metals which could expose the consumers to probable cancer risks and other biological process distraction.
