Resumo Os óleos essenciais podem ser extraídos de várias partes das plantas e apresentam diversas atividades biológicas. O Cerrado brasileiro possui uma grande variedade de plantas produtoras de óleos essenciais muitas delas ainda não estudadas. Levando-se em consideração a biodiversidade desse bioma, o objetivo deste trabalho foi avaliar a atividade antiproliferativa dos óleos essenciais extraídos de três espécies de plantas ocorrentes no Cerrado do estado de Goiás: Campomanesia adamantium (Cambess.) O. Berg, Protium ovatum (Engl. in Mart.) e Cardiopetalum calophyllum (Schltdl.). Os óleos essenciais foram obtidos das folhas de C. adamantium e C. calophyllum e das folhas e frutos verdes de P. ovatum por hidrodestilação, usando o aparelho do tipo Clevenger. A composição química dos óleos essenciais foi determinada pelo método de Cromatografia Gasosa acoplada à Espectrometria de Massas (CG-EM). Os constituintes químicos majoritários identificados nos óleos essenciais estudados foram: β-mirceno (62,00%), espatulenol (28,78%), germacreno-B (18,27%), óxido de β-cariofileno (16,40%), β-cariofileno (14,00%), α-pineno (11,30%), viridiflorol (9,99%), limoneno (7,30%) e (Z,E)-farnesol (6,51%). A atividade antiproliferativa foi avaliada em diferentes linhagens de células tumorais humanas: adenocarcinoma de mama (MCF-7), adenocarcinoma cervical (HeLa) e gliobastoma (M059J), além de, uma linhagem celular humana normal (GM07492A, fibroblastos pulmonares). O óleo essencial das folhas de C. adamantium exibiu menores valores de CI50 em todas as linhagens celulares tumorais avaliadas, sendo menores que aquele obtido na linhagem celular normal, indicando seletividade. Este é o primeiro relato da atividade antiproliferativa dos óleos essenciais de C. adamantium , P. ovatum e C. calophyllum contra células tumorais humanas.

Abstract Essential oils, which may be extracted from several parts of plants, have different biological activities. The Brazilian Cerrado has a large variety of plants that yield essential oils, even though many have not been studied yet. Taking into account the biodiversity of this biome, this study aimed at evaluating the antiproliferative activity of essential oils extracted from three species of plants of the Cerrado in Goiás state: Campomanesia adamantium (Cambess.) O. Berg, Protium ovatum (Engl. in Mart.) and Cardiopetalum calophyllum (Schltdl.). Essential oils were extracted from both C. adamantium and C. calophyllum leaves and from P. ovatum leaves and green fruits by hydrodistillation carried out by a Clevenger-type apparatus. The chemical composition of the essential oils was determined by Gas Chromatography coupled to Mass Spectrometry (GC-MS). The following major chemical constituents were identified in the essential oils under investigation: β-myrcene (62.00%), spathulenol (28.78%), germacrene-B (18.27%), β-caryophyllene oxide (16.40%), β-caryophyllene (14.00%), α-pinene (11.30%), viridiflorol (9.99%), limonene (7.30%) and (Z,E)-pharnesol (6.51%). The antiproliferative activity was evaluated in different human tumor cell lines: breast adenocarcinoma (MCF-7), cervical adenocarcinoma (HeLa) and glioblastoma (M059J). A normal human cell line was included (GM07492A, lung fibroblasts). Results showed that essential oils from C. adamantium leaves got the lowest values of IC50 in all strains of tumor cells under evaluation. They were significantly lower than the ones of the normal cell line, an evidence of selectivity. It is worth mentioning that this is the first report of the antiproliferative activity of essential oils from C. adamantium , P. ovatum and C. calophyllum against human tumor cells.

Resumo Este estudo avaliou as atividades antibacteriana e antiproliferativa do óleo essencial das folhas frescas de Psidium guajava (PG-OE), tradicionalmente utilizadas na medicina popular. O óleo essencial foi obtido por hidrodestilação das folhas frescas, utilizando aparelho do tipo Clevenger. Os principais constituintes químicos de PG-OE identificados por CG-EM e CG-DIC foram: β-cariofileno (16,1%), α-humuleno (11,9%), óxido de aromadendreno (14,7%), δ-selineno (13,6%) e selin-11-en-4α-ol (12,5%). A atividade antibacteriana do óleo essencial das folhas de P. guajava foi determinada em termo de sua concentração inibitória mínima (CIM) utilizando o método de microdiluição de caldo em microplacas de 96 poços. PG-OE apresentou moderada atividade contra Streptococcus mutans (CIM = 200 μg/mL), S. mitis (CIM = 200 μg/mL), S. sanguinis (CIM = 400 μg/mL), S. sobrinus (CIM = 100 μg/mL) e S. salivarius (CIM = 200 μg/mL). A atividade antiproliferativa foi avaliada frente a diferentes linhagens de células tumorais como: adenocarcinoma de mama (MCF-7), adenocarcinoma cervical humano (HeLa) e gliobastoma humano (M059J). Foi incluída uma linhagem celular humana normal (GM07492A, fibroblastos pulmonares). A atividade antiproliferativa foi avaliada utilizando o ensaio XTT e os resultados foram expressos como CI50. As linhagens MCF-7 e M059J mostraram valores significativamente mais baixos de CI50 do que os obtidos para a linhagem normal, mostrando seletividade. Nossos resultados sugerem que o óleo essencial das folhas frescas de Psidium guajava L. possui atividades biológicas promissoras e pode ser considerado como uma nova fonte de compostos bioativos.

Abstract This study evaluated the antibacterial and antiproliferative activities of the essential oil of Psidium guajava leaves (PG-EO), traditionally used in folk medicine. The essential oil was obtained from fresh leaves by hydrodistillation, using a modified Clevenger apparatus. The major PG-EO chemical constituents were identified by GC-MS and GC-FID as being β-caryophyllene (16.1%), α-humulene (11.9%), aromadendrene oxide (14.7%), δ-selinene (13.6%), and selin-11-en-4α-ol (12.5%). The antibacterial activity of the essential oil of P. guajava leaves was determined in terms of its minimum inhibitory concentrations (MIC) using the broth microdilution method in 96-well microplates. PG-EO had moderate activity against Streptococcus mutans (MIC = 200 µg/mL), S. mitis (MIC = 200 µg/mL), S. sanguinis (MIC = 400 µg/mL), S. sobrinus (MIC = 100 µg/mL), and S. salivarius (MIC = 200 µg/mL). The antiproliferative activity was evaluated against different tumor cell lines: breast adenocarcinoma (MCF-7), human cervical adenocarcinoma (HeLa), and human gliobastoma (M059J). A normal human cell line (GM07492A, lung fibroblasts) was included. The antiproliferative activity was evaluated using the XTT assay and the results were expressed as IC50. The essential oil showed significantly lower IC50 values against MCF-7 and M059J lines than that obtained for the normal line, showing selectivity. Our results suggest that the essential oil of Psidium guajava L. has promising biological activities and can be considered a new source of bioactive compounds.

Since 1949, a great deal of research has been carried out on the radioprotective action of chemical substances. These substances have shown to reduce mortality when administered to animals prior to exposure to a lethal dose of radiation. This fact is of considerable importance since it permits reduction of radiation-induced damage and provides prophylactic treatment for the damaging effects produced by radiotherapy. The following radioprotection mechanisms were proposed: free radical scavenger, repair by hydrogen donation to target molecules, formation of mixed disulfides, delay of cellular division and induction of hypoxia in the tissues. Radioprotective agents have been divided into four major groups: the thiol compounds, other sulfur compounds, pharmacological agents (anesthetic drugs, analgesics, tranquilizers, etc.) and other radioprotective agents (WR-1065, WR-2721, vitamins C and E, glutathione, etc.). Several studies revealed the radioprotective action of Apis mellifera honeybee venom as well as that of its components mellitin and histamine. Radioprotective activity of bee venom involves mainly the stimulation of the hematopoietic system. In addition, release of histamine and reduction in oxygen tension also contribute to the radioprotective action of bee venom.