Evaluation of toxic/protective effects of the essential oil of Salvia officinalis on freshly isolated rat hepatocytes.

For this study the essential oil (EO) of sage (Salvia officinalis L.) was isolated from air-dried vegetative aerial parts of the plants by hydrodistillation and analysed by GC and GC-MS. A total yield of 12.07 mg of EO per g of plant dry mass was obtained and more than 50 compounds identified. The major compounds were cis-thujone (17.4%), alpha-humulene (13.3%), 1,8-cineole (12.7%), E-caryophyllene (8.5%) and borneol (8.3%). The EO fraction of sage tea was also isolated by partition with pentane and the respective components identified. The toxic and antioxidant protective effects of S. officinalis EO were evaluated on freshly isolated rat hepatocytes. Cell viability (LDH leakage), lipid peroxidation and glutathione status were measured in experiments undertaken with cells (suspensions of 1 x 10(6) cells per millilitre) exposed to EO alone (toxicity of the EO;t-BHP as positive control); and with cells exposed to EO and an oxidative compound (t-BHP) together (in EO protection evaluation; quercetin as positive control) for 30 min. The results show that the EO is not toxic when present at concentrations below 200 nl/ml; it was only at 2000 nl EO/ml that a significant LDH leakage and GSH decrease were observed indicating cell damage. In the range of concentrations tested, the EO did not show protective effects against t-BHP-induced toxicity.

Organ- and season-dependent variation in the essential oil composition of Salvia officinalis L. cultivated at two different sites.

More than 50 compounds were identified in essential oils from stems and leaves of Salvia officinalis L. plants harvested in July, in Arouca, in northern Portugal. About 40 of those compounds were also present in flower essential oils, collected from the same plants. alpha-Thujone was the major compound, representing about 55, 30, and 18% of the essential oils from stems, leaves, and flowers, respectively. Significant percentage variations in the main compound classes of the essential oils from shoots sampled over the year were recorded at two different sites in northern Portugal. From December to April, oxygenated monoterpenes (MO) decreased from approximately 67-72% to values of 42-43% of the essential oils. During the same time interval, the percentage of monoterpene hydrocarbons (MH) rose from 8-11% to 17-22%. At both sites, sesquiterpene hydrocarbons (SH) rose from approximately 7% in February to 19-22% in April, decreasing thereafter to approximately 9% in July. Oxygenated sesquiterpenes (SO) increased from a minimum of approximately 5% in July to a maximum of 8-11% in February, decreasing thereafter. The compounds that mostly accounted for the essential oil composition variation were alpha-pinene, beta-pinene, and camphene, as MH; alpha-thujone and camphor, as MO; alpha-humulene and beta-caryophyllene, as SH; and viridiflorol, as SO.