Heavy metal analysis and phytochemical screening of two indigenous species (zingiber officinale and centrosema pubescens) from Nigeria

The plant species (Rhizome of Zingiber officinale and leaves of Centrosema pubescens) were tested for antimicrobial activity on four bacterial, Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa and Escherichia coli and one fungi (Candida albican) of clinical importance. Paper disc assay was employed in the test. Results showed that the ethanolic extracts of both plants were active against the bacteria and the ethanolic extract of Centrosema pubescens exhibited a significant activity on Candida albicans. The phytochemical analysis carried out on Zingiber officinale and Centrosema pubescens revealed the presence of alkaloids, tannins, steroids, flavonoids, terponoid and cardial glycoside. The presence of these phytochemical supports the use of this plants as antimicrobial agent. The heavy metal analysis carried out revealed the presence of Manganese, Lead, Cadmium, Zinc and Chromium which are all within the maximum recommended level by WHO.