Correlative study of heavy metal content with biological importance of Solanum virginianum leaf extract

Abstract

Abstract Background Rapid urbanization and industrialization have greatly impacted the inherent soil composition. Heavy metals disposed in the environment by anthropogenic activities toxicate flora and ultimately affect the phytochemical profile of medicinal plants. We report here such an investigation of the heavy metal concentrations in the leaf extract of Solanum virginianum (S. virginianum). This work has been extended to observe the phytochemical constituents and antibacterial significance of leaf extracts in methanol and aqueous medium. Methods The metal concentration was analysed on ICE 3000 series atomic absorption spectrometer. The antibacterial assessment was carried by disc diffusion technique against three gram-negative (Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa) and one gram-positive (Staphylococcus aureus) bacteria. Results The content of Iron (Fe), Manganese (Mn), Zinc (Zn), and Lead (Pb) were 2.04, 0.47, 0.41, and 0.10 mg/L, respectively. Saponin and coumarin were present in both extracts. Various other phytochemicals like steroids, terpenoid, and flavonoid, were present only in the water extract, while tannin was present only on methanol extract. The methanol and aqueous extracts exhibited their highest inhibition on S. aureus with zones of inhibition of 12 mm and 14 mm, respectively. Conclusion The aqueous extract possessed more phytochemicals than the methanol extract, and the aqueous extract exhibited better antibacterial activity. The high Fe content in the leaf extract may suggest its use as an anaemic medicine. Other metal contents are under the WHO range.