The leaf essential oil hydrodistilled from Schinus molle grown in Costa Rica was characterised in terms of its chemical composition, antioxidant activity, ability to induce cytotoxicity and the mechanism of cell death involved in the process. As a result, 42 constituents, accounting for 97.2% of the total oil, were identified. The major constituents of the oil were beta-pinene and alpha-pinene. The antioxidant activity showed an IC(50) of 36.3 microg mL(-1). The essential oil was cytotoxic in several cell lines, showing that it is more effective on breast carcinoma and leukemic cell lines. The LD(50) for cytotoxicity at 48 h in K562 corresponded to 78.7 microg mL(-1), which was very similar to the LD(50) obtained when apoptosis was measured. The essential oil did not induce significant necrosis up to 200 microg mL(-1), which together with the former results indicate that apoptosis is the main mechanism of toxicity induced by S. molle essential oil in this cell line. In conclusion, the essential oil tested was weak antioxidant and induced cytotoxicity in different cell types by a mechanism related to apoptosis. It would be interesting to elucidate the role that different components of the oil play in the effect observed here, since some of them could have potential anti-tumoural effects, either alone or in combination.

The study analyzes the chemical composition of the essential oil obtained from the leaves of Ugni myricoides (Kunth) O. Berg (U. myricoides EO). The composition of the essential oil was characterized by GC-FID and GC-MS analysis, showing at least six major constituents: α-pinene (52.1%), 1,8-cineole (11.9%), α-humulene (4.6%), caryophyllene oxide + globulol (4.5%), humulene epoxide II (4.2%) and β-caryophyllene (2.9%). It demonstrates for the first time the systemic anti-hypernociceptive properties of this orally administered oil in inflammatory and neuropathic models of hypernociception in mice. The effects of U. myricoides EO and its major constituent, α-pinene, were compared with those of indomethacin or gabapentin, drugs used clinically to treat inflammatory and neuropathic processes. Like indomethacin (5 or 10 mg/kg, p.o.), U. myricoides EO (5-50 mg/kg, p.o.) was able to significantly prevent mechanical hypernociception induced by carrageenan or complete Freund's adjuvant (CFA) in mice. These effects were observed for up to 48 h after i.pl. injection of flogistic agents. Repeated treatment with U. myricoides EO (5-25 mg/kg, p.o.), α-pinene (5-50 mg/kg, p.o.), or gabapentin (70 mg/kg, p.o.) also abolished the mechanical sensitization induced by CFA, or following the partial ligation of the sciatic nerve (PLSN). The present results indicate that U. myricoides EO produces marked anti-hypernociceptive effects in carrageenan and CFA mechanical sensitization models, and also inhibited neuropathic pain-like behavior after PLSN with efficacy similar to that observed for indomethacin or gabapentin. The relevant effects shown by U. myricoides EO are related, at least in part, to the presence of α-pinene and may be of potential interest for the management of inflammatory and neuropathic pain.

Pimenta is a genus of flowering plants in the Myrtaceae family, which has about 15 species, mostly found in the Caribbean region of the Americas. Commonly used for culinary and medicinal purposes, the best known commercial species are allspice, P. dioica (P. officinalis) and bay rum, P. racemosa, but there is little information concerning P. guatemalensis. The aim of the present study was to identify the chemical composition of the leaf and fruit essential oils of P. guatemalensis. The extraction of essential oils of P. guatemalensis growing wild in Costa Rica was carried out by the hydrodistillation method at atmospheric pressure, using a modified Clevenger type apparatus. The chemical composition of the oils was analyzed by capillary gas chromatographyflame ionization detector (GC/FID) and gas chromatography-mass spectrometry (GC/MS) using the retention indices on DB-5 type capillary column. A total of 103 and 63 compounds were identified in the leaf and fruit oils, respectively, corresponding to 96.8% and 86.1% of the total amount of the oils. The leaf oil consisted mainly of eugenol (72.8%), and mono-and sesquiterpene hydrocarbons (18.2%). Among terpenes the major components were b-caryophyllene (8.2%) and terpinolene (3.0%). The fruit oil also consisted mainly of eugenol (74.7%) and minor amounts of oxygenated mono-and sesquiterpenes (7.3%), mainly caryophyllene oxide (3.3%). This is the first report of the chemical composition of the essential oils obtained from this plant species. Rev. Biol. Trop. 63 (1): 303-311. Epub 2015 March 01.Key words: Pimenta guatemalensis, Myrtaceae, essential oil composition, eugenol, b-caryophyllene, caryophyllene oxide, terpinolene, Costa Rica.Myrtaceae is a family constituted of about 142 genera and includes more than 5 500 species of mostly trees and shrubs with conspicuous oil glands, distributed predominantly in the Southern hemisphere, mainly in Australia and South America (Wilson, 2011).Worldwide, the family has a considerable economic value because species from several genera are used as a source of timber (for example, Eucalyptus globulus Labill., Tas (Barrie, 2007). In Costa Rica, it is commonly known as Jamaica (León, & Poveda, 2000). This plant is distributed along Central America, from Guatemala to Panama. The young branchlets are 4-angled. The leaves are evergreen, simple, opposite and oblanceolate to elliptical, the blade cuneate at the base and acuminate at the apex. When the leaves are crushed they give off a scent with an aromatic flavor resembling a mixture of clove and cinnamon due to an oil of unknown composition. The fragrant flowers are small and the receptacle has five calyx lobes, arranged in panicles (ca. 20 flowers) in the leaf axils. The ovaries are uni-locular or without loculi. This plant grows wild in Costa Rica and it can be found distributed between 250 and 900m above sea level mostly in the rain forests of the North region and Caribbean slopes. To the best of our knowledge, no previous reports on the chemistry of P. guatemalensis hav...

A composição química dos óleos essenciais obtidos de folhas, cascas e troncos de Ocotea gomezii e O. morae de populações silvestres da Costa Rica, está sendo descrita pela primeira vez. Os óleos de O. gomezii são constituídos principalmente por sesquiterpenóides enquanto os de O. morae apresentaram mono-e sesquiterpenóides na mesma proporção. A análise da composição química por CG/EM e CG/DIC resultou na identificação de 166 componentes, correspondente a 89,4-98,1% dos óleos totais. Quando comparada a atividade de todos os óleos obtidos sobre linhagens de células CCF-STTG1, Hep3B, HepG2, H-460, AGS, N-87, SW-620, MCF-7 e VERO, observou-se que as células de astrocitoma foram as mais resistentes aos mesmos. Concluiu-se que os óleos essenciais de folhas, cascas e tronco de Ocotea gomezii e Ocotea morae podem conter alguns compostos tóxicos, mas o uso potencial dos mesmos contra as células tumorais foi muito baixo, pois são tóxicos na mesma extensão, para as linhagens de células tumorais e não-tumorais. The chemical composition of the essential oils of the leaves, bark and wood of Ocotea gomezii and O. morae from Costa Rica, were analyzed by capillary GC-FID and GC-MS. The oils of O. gomezii were predominantly composed by sesquiterpenoids whereas the oils of O. morae had both monoterpenoids and sesquiterpenoids. Analysis by GC/MS and GC/FID resulted in the identification of 166 compounds, representing about 89.4−98.1% of the total oils. When we compared the effect of the oils on cell lines (CCF-STTG1, Hep3B, HepG2, H-460, AGS, N-87, SW-620 and MCF-7 and VERO), we found that astrocytoma cells were the most resistant ones. We conclude that the essential oils of Ocotea gomezii and Ocotea morae could have some toxic compounds, but the potential use of them against the tumor cells would be very low, since they could be toxic to tumor and non-tumor cells in the same extent.

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