ABSTRACT
Aims: Melissa officinalis (Mo) and Lavandula angustifolia (La) essential oils and their major constituents ((E) - caryophyllene, caryophyllene oxide, geranyl acetate, linalool, nerol, Oct-1-en-3-ol, 3-Octanone, myrcene, allo-ocimene, p-cymene and α- terpineol) assessed by GC-MS) which are shared by these two essential oils were probed in an attempt to identify the GABAAR ligand(s). Study Design: [35S] t-butylbicyclophosphorothionate (TBPS) radioligand binding assay to GABAA receptors. In vitro neuronal viability assay. Place and Duration of Study: School of Biological and Biomedical Sciences, Durham University, United Kingdom (December 2012 and January 2013). Results: One of the major component (s) of (Mo), trans-ocimene, inhibited [35S] (TBPS) binding to native GABAA receptors in a concentration-dependent manner with an apparent IC50 of 40μM. Concentrations (0.001 mg/ml) of whole (Mo) were shown to display modest beneficial effects upon neuronal viability while at a higher concentration (0.1 mg/ml) of (Mo) and (La) oils induced a neurotoxicity effect. Conclusion: These data provide the first evidence that allo-ocimene is an neuroactive GABAA R inhibitory component found in both (Mo) and (La), and represents a novel GABAA receptor channel chemotype derived from a natural product.
ABSTRACT
Aims: To determine the antibacterial effect of crude methanolic extracts of six selected medicinal plants grown in Jordan (Paronychia argentea Lam., Inula viscosa L., Arbutus andrachne L., Asphodelus microcarpus Salzm et Vivi, Peganum harmala L. and Aloysia citriodora Palau) against Bacillus subtilis, Staphylococcus aureus and Escherichia coli. Study Design: In vitro assessment antibacterial study. Place and Duration of Study: Department of Biopharmaceutics and Clinical Pharmacy, Faculty of Pharmacy, University of Jordan, Amman, Jordan. Between (December 2012 and January 2013). Methodology: In-vitro Laboratory experimental tests; preparation of plant extracts, phytochemical screening; susceptibility tests (zones of inhibition) and minimum inhibitory concentration (MIC) determination. Results: While the crude methanolic extract of P. argentea, A. andrachne, A. microcarpus had no antibacterial activity, crude extract of P. harmala showed good antibacterial activities against all the tested bacterial strains. MIC values for the seed and root extract of against S. aureus were 0.375 mg/ml and 1.5 mg/ml respectively while MIC values for seed and root extracts against B. subtilis were 0.375 and 6.25 mg/ml, respectively and also showed week activity against Gram negative bacteria. The crude methanolic extract of I. viscosa and A. citriodora was also active against bacterial strains S. aureus and B. subtilis and inactive against E. coli. MIC value for I. viscosa extract against S.aureus were 6.25 mg/ml and against B. subtilis 0.375 mg/ml. Meanwhile, MIC value for A. citriodora against S. aureus were 12.5 mg/ml and against B. subtilis 1.5 mg/ml. Conclusion: Results indicate the potential antibacterial activity of I. viscosa and A. citriodora towards Gram positive bacteria such as B. subtilis and S. aureus. The extracts phytochemical screening revealed the presence of terpenoids, flavonoids and phenolics. These preliminary results would be a guide in the selection of potential candidates for further pharmacological study and in search of new drug candidate for treatment of infections caused by Gram positive bacteria.