Elemental profiles of herbal plants commonly used for cancer therapy in Ogun State, Nigeria. Part I

The concentrations of 51 elements in 32 herbal plants belonging to 22 botanical families commonly used as recipe for cancer treatment in Abeokuta, Ogun State, Nigeria were determined using inductively coupled plasma mass spectrometry (ICPMS). A closed vessel nitric acid microwave assisted digestion method, using an UltraCLAVE III was employed for the digestion of the plants. The accuracy of the results was checked by using certified reference materials: peach leaves (NBS CRM 1547), pine needles (NBS CRM 1575) and trace elements in water (NIST SRM 1643e). The results obtained for these reference materials showed good agreement with the certified concentrations. Elemental composition in the analyzed plant samples varied widely. The highest concentrations of the minerals Ca (67.4 mg g− 1), K (55 mg g− 1), Na (5.59 mg g− 1), Mg (8.99 mg g− 1) and P (5.89 mg g− 1) were found in Terminalia avicennioides, Nicotina tabacum, Pyrenacantha staudii, Chenopodium ambrosioides and N. tabacum respectively. Cd, Co, Fe Pb, Hg, Ni and Zn exceeded the FAO/WHO limits in some herbal plants. Estimated infusion concentrations for mineral and essential trace elements showed that some of the plants may be present in the 50th percentile of the FAO/WHO limit. Rare earth elements concentration ranged from < 0.04 μg g− 1 for Ho in some of the plants to 24.1 μg g− 1 for Ce in P. staudii. The variation in some essential but toxic elements in Pistia stratiotes, P. staudii, Parquetina nigrescens, N. tabacum and C. ambrosioides calls for further investigation of these plants.