Antibacterial activities of metal-natural extract complexes

Metal-based compounds consist of an organic substituent as the ligand and an inorganic substituent as the metal center. Natural products, particularly natural extract, are well known to exhibit excellent biological activities, while the inorganic substituents are usually metal ions. Metal ions, especially transition metals, exhibit different oxidation states and can interact with any ligands. Advances in inorganic chemistry provide better opportunities to use metal-based compounds as therapeutic agents. The mode of action of these metal-based compounds on living organisms is different from non-metals. The unique properties of metal ions should be exploited to design new compounds. Pluchea indica (L.) Less (locally known as Beluntas), Clinacanthus nutans (locally known as Belalai Gajah), and Phyllanthus niruri (locally known as Dukung Anak) are medicinal plants that possess various biological properties. Incorporation of transition metal ions (Cu2+, Ni2+, Co2+, Zn2+) into the crude extracts from these medicinal plants would give metal-natural extract complexes of the plants. Leaves of Pluchea indica (L.) Less, Clinacanthus nutans, and Phyllanthus niruri were collected and extracted with either methanol or ethanol and reacted with various transition metal salts to yield metal-natural extract complexes. The metal-natural extract complexes were assessed for their antibacterial activities using quantitative and qualitative antibacterial assays against four pathogenic bacteria, which were Staphylococcus aureus (ATCC 29213), Bacillus cereus (ATCC 117788), Pseudomonas aeruginosa (ATCC 27853), and Escherichia coli (ATCC 25922). The antibacterial assays showed that the biological activities of the metal-natural extract complexes were enhanced and selective towards selected target bacteria. It was found that the identity of transition metal ions plays an important role in enhancing the bioactivity exhibited by the metal-natural extract complexes. The results showed that these metal-natural extract complexes of Pluchea indica (L.) Less, Clinacanthus nutans, and Phyllanthus niruri are potential alternative antibacterial agents

Antimicrobial activities of metal-natural extract complexes

Pluchea indica (L.) less, Clinacanthus nutans and Phyllanthus niruri are traditional herbs that possess some biological properties. This research is carried out to synthesize metal-natural extract complexes of Pluchea indica (L.) less, Clinacanthus nutans and Phyllanthus niruri and to study the antimicrobial of the metal-natural extract complexes. Leaves of Pluchea indica (L.) less, Clinacanthus nutans and Phyllanthus niruri were collected and extracted with methanol and ethanol and synthesized with various transition metal salts to yield metal-natural extract complexes. The metal-natural extract complexes were assessed for the antimicrobial activity using the disc diffusion method and determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against four pathogenic bacteria which are Staphylococcus aureus (ATCC 29213), Bacillus cereus (ATCC 117788), Pseudomonas aeruginosa (ATCC 27853) and Escherichia coli (ATCC 25922). Investigation of antimicrobial activities of the complexes against the tested microorganisms showed that the metal-natural extract complexes were found to be more active against the organisms than the crude extracts itself. This study shows the potential of metal-natural extract complexes of Pluchea indica (L.) less, Clinacanthus nutans and Phyllanthus niruri as source of antimicrobial agents that will give contribution to the field of medical and pharmaceutical