Extensive study on the pharmaceutical constituents of leaf and root of Costus after (ker)

Abstract An extensive investigation has been carried out on Costus afer (ker) plant leaves and roots so as to ascertain its secondary metabolites. The qualitative phytochemical assay indicated the presence of tannins, saponins, steroids, terpenoids, alkaloids, resins, protein, reducing sugar, starch and glycosides in the plant leaves and roots. The micro elemental analysis confirmed that it contained Iron (0.053mg/2g), Calcium (0.025mg/2g), Magnesium (0.016mg/2g) Potassium (0.018mg/2g), Chromium (0.008 mg/2g), Lead (0.006mg/2g) and Cadmium (<0.001mg/2g) taken in their descending order of concentration. The melting point of the extracted and purified alkaloid extract was 157oC for the leaves and 172oC for the roots. The Rf value for the thin layer chromatography of the alkaloid extract was 0.57 and 0.84 for the leaves and roots respectively. The UV result showed that the alkaloid was a conjugated mono-substituted aromatic amide. The anti-fungal and anti-bacterial assay indicated strong inhibitory effects against the test organisms such as Staphyloccus aureus, Streptococcus specie, Salmonella specie, Enterobacter aerogenes, Klebsiella aerogenes, Bacillus specie, Pseudomonas pyocyania, Proteus vulgaris, Candida albican, Aspergillus flavus and Aspergillus niger. The pharmacological analysis proved that the leaves and roots of the plant has medicinal values. The dosage at which the crude drugs are dangerous or detrimental to human, its toxicological effect and structure should be investigated.