Comparative study of antibacterial activity and mineral contents of various parts of Verbena officinalis Linn.

Verbena officinalis Linn., a wild herb found in Pakistan and many other parts of the world, is known for its rich folkloric and traditional medicinal applications. The present study deals with antibacterial activities and mineral content of different parts of the plant. Antibacterial activities of the ethanolic extracts of leaves, stems and roots were studied against five ATCC standard strains which include Staphylococcus aureus (ATCC25923), Escherichia coli (ATCC25922), Pseudomonas aeruginosa (ATCC27853), Enterococcus faecalis (ATCC29212) and Acinetobacter baumannii (ATCC29213) and eight clinical isolates including MRSA (n = 4) and MDR Salmonella typhi (n = 4). All the plant parts showed highest efficacy against S. aureus, while stems exhibited, in general, better antimicrobial activity than leaves and roots. Sodium, potassium, magnesium, iron, cadmium, nickel, copper, zinc, manganese, chromium, cobalt and lead were estimated in leaves, roots, stems, seeds and seed husk of V. officinalis. All plant parts are good source of potassium, which is approximately 4 times higher than sodium, seed husk being the richest in potassium showed highest potassium to sodium ratio (4492/897). Roots contain higher values of iron (1763.14 ppm) and manganese (117.29 ppm), while seed husk contains higher quantities of magnesium (778.53 ppm) and zinc (54.00 ppm). Chromium, cobalt and lead were not found in any part of the plant studied.