MEDICINAL HERBS AS A SOURCE OF ANTIMICROBIAL SUBSTANCES.

This study aimed to test a variety of naturally occurring some medicinal herbs and their extracts for their antimicrobial potential against a group of some bacterial and fungal pathogens. A total of 6 herbs (Thymus vulgaris, Foeniculum vulgare, Datura stramonium, Matricaria chamomilla, Ammi visnaga linne and Cassia angustifolia) collected from famous Egyptian plant dealers. The antimicrobial activity of aqueous, Methanol and Petroleum ether extracts were assisted by measuring the inhibition zone by agar well diffusion method and minimum inhibitory concentration (MIC) in order to increase the reliability and precision of the study. A number of 5 bacterial, 3 fungal (Molds) and 1(Yeast) species were chosen: G+ Bacteria: Staphylococcus aureus (RCMB 010027), Bacillis subtilis (RCMB 000101(5)). G- Bacteria: Pseudomonas aeruginosa (RCMB 000102(3)), Escherichia coli (RCMB 000103(9)), Klebsiella pneumonia (RCMB 0010093(12)). Fungi (molds): Aspergillus fumigates (RCMB 02564), Penicillium italicum (RCMB 001003), Syncephalastrum racemosum (RCMB 005003), and (yeast): Candida albicans (RCMB 05035). The three different solvents gave markedly varied abilities to extract the antimicrobial compounds active against versatile groups including G+, G- bacteria and fungi. The active antagonism of crude methanolic extract can be descendingly arranged as thyme>senna>fennel>Datura>chamomil. The extract from Ammi vesnaga gave negative results. The hyphal fungi, Penicellium italicum was less antagonized (11.1 – 21.9 mm IZ) than Aspergillus fumegatus ( 12.3 – 22.6 mm IZ), and Syncephalastrum racemosum (12.6 – 20.9 mm IZ), whereas Candida albicans was not affected by any methanolic extract of 5 herb types and the sixth (thyme) gave relatively moderate activity (20.9 mm IZ). Methanolic extracts gave in MICs of 0.015-7.81 µg/ml (Thyme), 0.49 – 125 µg/ml (Senna) and 31.25 – 500 µg/ml (Fennel) compared to MICs of 3.9 – 500 µg/ml, 31.25 – 500 and 15.63 – 500 µg/ml for those of ether extracts respectively in the same order of herbs. Essential oil and extracts of two herbs (Thymus vulgaris, Foeniculum vulgare), were analysis by Gas chromatography/mass spectrometry analysis revealed the presence of 12 peaks in fennel essential oil which indicating the presence of 12 phytochemical constituents representing 100% of the oil, while GC-MS analysis revealed the presence of 18 peaks in Thyme essential oil which indicating the presence of 14 phytochemical constituents representing 99.98% of the oil. The major constituents of the essential oil in fennel were Anethol (63.37%), D-Limonene (20.18%), L-Fenchone (7.44%) and Estragole (3.40%). The major constituents of the essential oil in thyme were Thymol (62.16%), o-Cymene (9.75%), Caryophyllene (7.30%), ?-Terpinene (5.66%), Butylated hydroxyl onisole (5.39%).