Phytochemical Composition and In Vitro Antibacterial Activities of Millettia Chrysophylla and Millettia Zechiana

Mary Anti Chama; Beverly Egyir; Kofi Baffour-Awuah Owusu; Mitsuko  Ohashi

doi:10.4314/just.v40i1.1263

Mary Anti Chama (PhD) Department of Chemistry, University of Ghana
Beverly Egyir (PhD) Bacteriology Department, Noguchi Memorial Institute for Medical Research, University of Ghana
Kofi Baffour-Awuah Owusu Noguchi Memorial Institute for Medical Research, University of Ghana
Mitsuko Ohashi Noguchi Memorial Institute for Medical Research, University of Ghana

DOI: https://doi.org/10.4314/just.v40i1.1263

Keywords: phytochemicals, Methicillin-Resistant Staphylococcus aureus (MRSA), bacteria, Millettia zechiana, Millettia chrysophylla

Abstract

Millettia chrysophylla (MC) and Millettia zechiana (MZ) are two medicinal plants distributed in Africa. MZ is used traditionally to treat infectious diseases. Current literature survey suggests no scientific studies on MC and phytochemical studies on MZ were scanty with no biological activities. In vitro antibacterial activities of the ethanol extracts of the leaves (L), stems (S), and roots (R) for both plants, and flowers (F) and twigs (T) for MZ were tested against eight laboratory bacteria strains and 28 clinical isolates of Methicillin-Resistant Staphylococcus aureus (MRSA). The chemical profile of the extracts was obtained by Gas Chromatography Mass Spectrometry (GCMS) whiles characterisation of the alkaloid, flavonoid, and tannin contents were also determined. MCS extract showed a strong and broad activity against S. epidermidis (8.79 μg/mL), E. coli (3.9 μg/mL), S. enteritidis (5.11 μg/mL) and B. cereus (5.33 μg/mL). Broad bactericidal activity against MRSA strains: MR21, MR4 and MR19 with respective IC₅₀ values of 72.30, 86.45 and 97.76 µg/mL were showed by MCL extract. The major components identified from the GCMS analysis included 17-octadecenoic acid (39.46%), 17-octadecynoic acid (27.90%) n-decanoic acid (27.88%), (Z, Z)-9,12-octadecadienoic acid (27.02%), (Z)-18-octadec-9-enolide (24.46%), and n-hexadecanoic acid (20.87%). MCL indicated 6.97±0.62 mg CA/g, 3.75 ± 0.12 mg TA/g, and 3.58 ± 0.18 mg RU/g for the respective contents of alkaloids, tannins, and flavonoids. These findings have given insights into the phytochemicals of M. chrysophylla and the antibacterial activities of leaves, stems and roots of M. chrysophylla and the twigs of M. zechiana for further drug discovery research.

Author Biographies

Mary Anti Chama (PhD), Department of Chemistry, University of Ghana

Mary Anti Chama is a Senior Lecturer and Head at the Department of Chemistry, University of Ghana with over 10 years of teaching and research. Her research area is in Medicinal plant Natural Product Chemistry with integration of in silico methods towards drug discovery and mode of action of medicinal plants. She focuses on the quest for biologically active compounds from plants in treating infections of neglected tropical fields, bacterial and fungal diseases as well as activities against cancer cell lines.

Beverly Egyir (PhD), Bacteriology Department, Noguchi Memorial Institute for Medical Research, University of Ghana

Dr. Beverly Egyir is a Senior Research Fellow and a bacteriologist at the Bacteriology Department, Noguchi Memorial Institute for Medical Research, University of Ghana. She has been involved in using phenotypic and molecular tools to generate for the first time, a comprehensive baseline data on the carriage frequency, antimicrobial resistance patterns and clonal lineages of S. aureus in Ghana; a useful information to guide antimicrobial therapy, and for effective surveillance. Dr. Egyir’s current research interest is on epidemiology of antimicrobial resistant bacteria of public health importance.

Kofi Baffour-Awuah Owusu , Noguchi Memorial Institute for Medical Research, University of Ghana

Kofi Baffour-Awuah Owusu is a Microbiologist and a Senior Research Associate at the Noguchi Memorial Institute for Medical Research, Biomedical research Center, University of Ghana. He has over 10 years of experience with interest in drugs, toxicology, and Analytical chemistry.

Email: kowusu@noguchi.ug.edu.gh

Mitsuko Ohashi, Noguchi Memorial Institute for Medical Research, University of Ghana

Mitsuko Ohashi is a Parasitologist at the Noguchi Memorial Institute for Medical Research, Biomedical research Center, University of Ghana. Her research area is on drug discovery of protozoans, Trypanosome, Leishmania and Malaria with over 10 years of experience.