Central Properties and Chemical Composition of Ocimum basilicum Essential Oil

Ocimum basilicum L. (Lamiaceae) is an Egyptian plant used as a folkloric remedy in Egyptian traditional medicine. In the current study, the aerial part of this plant was used, and its essential oil was obtained by hydrodistillation. The essential oil of Ocimum basilicum (OB) was screened for its composition and some CNS activities (viz., sedative, hypnotic, anticonvulsant, local anesthetic). When tested in mice, OB essential oil had no effect on motor activity up to a dose of 1.2mLkg 1 at 90min postadministration. However, higher doses produced motor impairment at all time intervals. Pentobarbitone sleeping time tested in mice was significantly increased by all doses of the essential oil higher than 0.2mLkg . Intraperitoneal administration of OB essential oil significantly increased in a dose-dependent manner the latency of convulsion and percent of animals exhibiting clonic seizures. Likewise, it reduced lethality in response to different convulsive stimulus used in this study. The ED50 values of the essential oil of OB were 0.61mLkg , 0.43mLkg , and 1.27mLkg , against convulsions induced by pentylenetetrazole, picrotoxin, and strychnine, respectively. A study of the local anesthetic activity of the OB essential oil by using a nerve block model employing in frog revealed that it had no local anesthetic effect. The LD50 of the essential oil was 3.64mLkg 1 [correlation coefficient r1⁄40.961 and linear regression y1⁄4147 ln(x) 141.7]. Gas chromatography (GC)=mass spectrometry (MS) analysis of the essential oil revealed the presence of linalool (44.18%), 1,8-cineol (13.65%), eugenol (8.59%), methyl cinnamate (4.26%), iso caryophyllene (3.10%), and a-cubebene (4.97%) as the main components. The observed anticonvulsant and hypnotic activities in this study could be related to the presence of a variety of terpenes in the essential oil.