Assessment of Heavy Metal Contamination in the Leaves of the Medicinal Plant Pterocarpus marsupium Roxb. (Fabaceae) consumed in Senegal: Implication for Human Health

Abstract

Pterocarpus marsupium Roxb. (Fabaceae), known as "Indian Kino," "Vijayasar," or "Malabar Kino," is a deciduous tree with high medicinal value used for centuries in traditional African, Ayurvedic, and Unani medicine. Pterocarpus marsupium is widely used in traditional medicine for its antidiabetic properties, particularly due to its wood and bark extracts which help regulate blood sugar levels. It is also used for its anti-inflammatory and healing properties, contributing to the treatment of wounds, skin infections, and certain digestive disorders. This study aims to characterise the composition of eleven metallic elements in the leaves of this species by atomic absorption spectrometry (AAS) and assess the biohazard risks associated with each detected element, with reference to World Health Organisation (WHO) regulatory thresholds and International Agency for Research on Cancer classifications (IARC). The results reveal a predominance of calcium (59.27 mg/g Dry Matter (DM)), followed by potassium (10.61 mg/g DM) and magnesium (2.02 mg/g DM). Cadmium was quantified at trace levels (0.0010 mg/g DM), while lead and chromium were not detected. The toxicological assessment indicates an overall favourable biohazard profile, with two areas of concern: nickel for topical use in atopic individuals, and cadmium for chronic exposure. These results contribute to the scientific development and safety of medicinal uses of this species. Further investigations into the oral bioavailability of these elements, the effects of traditional preparation methods such as decoction and maceration on their metal concentrations, and the influence of geographical variation on mineral composition are warranted. Such studies would provide a more comprehensive understanding of the potential risks and benefits associated with the medicinal use of Pterocarpus marsupium Roxb. leaves. Moreover, the resulting evidence would contribute to refining health risk assessments and establishing a stronger scientific foundation for their safe, effective, and rational therapeutic application.