Thesis Abstract

The aqueous and ethanolic extracts of the leaves of Thymus vulgaris (thyme) and the seeds of Myristica fragrans (nutmeg) were screened for their antibacterial activity and phytochemical constituents. The standard methods used to detect the phytochemicals present in the extracts revealed the presence of tannins, flavonoids, triterpenoids and phytosterols in all the extracts while steroids and amino acids were absent. The antibacterial evaluation of the spice extracts using agar plate-well diffusion and nutrient broth dilution techniques showed thatthere was no significant difference in the activity of the spice extracts (p > 0.05) against the test organisms (Streptococcus pneumoniaeand Pseudomonas aeruginosa, clinical bacterial isolates). Ampiclox and chloramphenicol were used as control for the test organisms to provide approximate basis for the comparison of the activity of the extracts. The MIC and MBC was the same for all the extracts against S. pneumoniae, 6.25 mg/ml while 25 mg/ml for thyme extracts, and 50 mg/ml for nutmeg extracts against P. aeruginosa, showing the extracts to be bactericidal.

Thesis Overview

The spread of drug-resistant pathogens is one of the most serious threats to public health in the 21st century. Although pharmacological industries have produced a number of new antibiotics in the last three decades, resistance to these drugs by micro-organisms still remains. In general, bacteria have the genetic ability to transmit and acquire resistance to drugs, which are utilized as therapeutic agents (Cohen, 1992). Such a fact is a cause for concern, because of the number of patients in hospitals who have suppressed immunity, and due to new bacterial strains that are multi-drug resistant. Consequently, new infections can occur in hospitals resulting in high mortality as observed by Montelli and Levy (1991).

The use of herbs as first medicines is a universal phenomenon. For a long period of time, plants have been a valuable source of natural products for maintaining human health, especially in the last decade, with more intensive studies for natural therapies. Most drugs of the past were substances with a particular therapeutic action extracted from plants. Thus, medicinal plants may be defined as any plant that can be put to culinary use such as onions, fox glove, garlic and ginger (Wainright, 2001). More and more researchers find that food and their individual constituents perform similar fashion to modern drugs and sometimes better without the dreaded side effects (Serrentino, 1991).

Plant extracts have great potential as antimicrobial compounds against micro-organisms (Gisleneet al., 2000) and studies have reported that they can be used in the treatment of infectious diseases caused by resistant microbes.Thymus vulgaris (thyme) leaves andMyristicafragrans(nutmeg) seeds are plants parts that are widely used as spices for cooking especially for flavouring meats, soups and stews. They have also been reported to have medicinal uses and possess antimicrobial abilities(Stahl-BiskupandSaez, 2002; Cho et al., 2006; Na