Abstract:
Leaves of Plantago lanceolata were traditionally used to treat wounds, burns, inflammations,
fevers, diabetes and cancer. The present study was carried out on the phytochemical
investigation and antimicrobial activities of the leaves extract of Plantago lanceolata since the
plant was used for wound healing in Ethiopia. The powdered leaves of Plantago lanceolata
herb was sequentially extracted with organic solvents: petroleum ether, chloroform/methanol
(1:1) and methanol, respectively. The crude extracts were subjected to phytochemical
screening and revealed the presence of steroids, alkaloids, flavonoids, saponins, glycosides,
phenols, tannins and terpenoids that might be responsible for the claimed activities by local
people. The petroleum ether extract was subjected to silica gel preparative thin layer
chromatography to yield compound PL-5. The structure of this compound was elucidated
using different spectroscopic techniques such as FT-IR, 1
H-NMR, 13C-NMR and DEPT-135
and also by comparing the data with literature reports. The n-hexane extracted oil was
investigated by GC-MS and showed the presence of 26 compounds. Among which, the major
constituents of leaf oil were 9-Octadecenoic acid (24.20%) and hexadecanoic acid (23.65%).
The crude extracts, isolated pure compound and n-hexane extracted oil were tested against four bacterial species (Gram negative bacteria: Escherichia coli and Salmonela thyphei;
Gram positive bacteria: Staphylococcus aureus and Streptococcus agalactiae) and two fungal
species (Aspergillus niger and Fusarium solani) using paper disc diffusion method. All crude
extracts, isolated pure compounds and extracted oil were active against all the tested bacterial
species. Additionally petroleum ether and chloroform/methanol (1:1) crude extracts and nhexane
extracted oil were active against the two fungal species and hence the present work
may support the medicinal use of plantago lanceolata.
