In vitro antiparasitic activity and chemical composition of the essential oil from Protium ovatum leaves (Burceraceae).

Leishmaniasis and trypanosomiasis are globally widespread parasitic diseases which have been responsible for high mortality rates. Since drugs available for their treatment are highly hepatotoxic, nephrotoxic and cardiotoxic, adherence to therapy has been affected. Thus, the search for new, more effective and safer drugs for the treatment of these diseases is necessary. Natural products have stood out as an alternative to searching for new bioactive molecules with therapeutic potential. In this study, the chemical composition and antiparasitic activity of the essential oil from Protium ovatum leaves against trypomastigote forms of Trypanosoma cruzi and the promastigote forms of Leishmania amazonensis were evaluated. The essential oil was promising against trypomastigote forms of T. cruzi (IC50= 28.55 µg.mL-1) and L. amazonensis promastigotes (IC50 = 2.28 µg.mL-1). Eighteen chemical constituents were identified by Gas Chromatography coupled to Mass Spectrometry (GC-MS) in the essential oil, whose major constituents were spathulenol (17.6 %), caryophyllene oxide (16.4 %), ß-caryophyllene (14.0 %) and myrcene (8.4 %). In addition, the essential oil from P. ovatum leaves had moderate cytotoxicity against LLCMK2 adherent epithelial cell at the concentration range under analysis (CC50 = 150.9 µg.mL-1). It should be highlighted that this is the first report of the chemical composition and anti-Trypanosoma cruzi and anti-Leishmania amazonensis activities of the essential oil from Protium ovatum leaves.

Limonoids and insecticidal activity on Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) of Trichilia catigua A. Juss. (Meliaceae).

The aim of the study was to evaluate the effects of the seeds, exocarp and aril extracts from Trichilia catigua A. Juss. (Meliaceae) against Spodoptera frugiperda and present the phytochemical study carried out with the aril extract of T. catigua. Limonoids were isolated from the aril of T. catigua through chromatographic techniques and their structures were proposed by spectroscopic analysis and comparison with literature data. The effects of the seeds, exocarp and aril extracts from T. catigua against S. frugiperda were evaluated considering as parameters the duration and mortality of the larval phase, in addition to the pupal weight. Phytochemical investigation of the aril extracts of T. catigua has led to the identification of the limonoids 6α-O-acetyl-7-deacetyl-14,15-dihydro-15-oxo-nimocinol (1), cedrelone (2) and 6α-O-acetyl-7-deacetylnimocinol (3). The hexane and CH2Cl2 extracts of the aril showed a high rate of larval mortality (100 and 90%, respectively). In addition, a prolongation of larval phase and a reduction in the pupal weight were observed for insects treated with hexane, CH2Cl2 and methanol extracts of seeds and with CH2Cl2 extract of exocarp of T. catigua.

Chemical composition and antifungal activity of Zanthoxylum riedelianum stem bark essential oil.

The phytopathogenic fungi Sclerotinia sclerotiorum and Rhizopus stolonifer infect different crop plants. Essential oils have been used as an alternative to chemical control methods. Therefore, the objective of this study was to analyze the essential oil chemical composition of the stem bark of Zanthoxylum riedelianum (ZREO) and evaluate its antifungal potential. The ZREO obtained by hydrodistillation was analyzed using gas chromatography coupled to mass spectrometry and evaluated for in vitro antifungal activity. The major components identified in the chemical analysis were E-nerolidol (67.21%), α-selinene (14.94%), and ß-selinene (7.41%). The antifungal potential of ZREO against S. sclerotiorum and R. stolonifer was detected at all concentrations evaluated in a dose-dependent manner. The best results were against R. stolonifer, with the concentration of 150 µLmL-1 inhibiting more than 80% of mycelial growth. On the basis of the current knowledge, this study describes for the first time the chemical composition and their antifungal activity.

Phytotoxicity of triterpenes and limonoids from the Rutaceae and Meliaceae. 5α,6ß,8α,12α-Tetrahydro-28-norisotoonafolin--a potent phytotoxin from Toona ciliata.

Limonoids and triterpenes are the largest groups of secondary metabolites and have notable biological activities. Meliaceae and Rutaceae are known for their high diversity of metabolites, including limonoids, and are distinguished from other families due to the frequent occurrence of such compounds. The increased interest in crop protection associated with the diverse bioactivity of these compounds has made these families attractive in the search for new allelopathic compounds. In the study reported here we evaluated the bioactivity profiles of four triterpenes (1-4) and six limonoids (5-10) from Meliaceae and Rutaceae. The compounds were assessed in a wheat coleoptile bioassay and those that had the highest activities were tested on the standard target species Lepidinum sativum (cress), Lactuca sativa (lettuce), Lycopersicon esculentum (tomato) and Allium cepa (onion). Limonoids showed phytotoxic activity and 5α,6ß,8α, 12α- tetrahydro-28-norisotoonafolin (10) and gedunin (5) were the most active, with bioactivity levels similar to, and in some cases better than, those of the commercial herbicide Logran. The results indicate that these products could also be allelochemicals involved in the ecological interactions of these plant species.

Natural compounds with cell growth inhibitory activity in human tumor cell lines.

Twenty six compounds (coumarins, flavonoids and alkaloids) were evaluated for their ability to inhibit the growth of three human tumor cell lines: breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and melanoma (A375-C5). Three of them [3-hydroxyflavone (6), 2'-hydroxy-3,4,4',5,6'-pentamethoxychalcone (11), Siderin (20)] were very potent in inhibiting all human tumor cell lines tested. The structure / activity relationship is discussed.

Effects of limonoid cedrelone on MDA-MB-231 breast tumor cells in vitro.

Cancer is the second leading cause of death, preceded only by cardiovascular diseases, and there is epidemiological evidence that demonstrate this tendency is emerging worldwide. Brazil has an extensive vegetal biodiversity with more than 55,000 species listed. Such biodiversity collaborates with the finding of compounds which could be the basis for the design of new anti-tumor drugs, with fewer side effects than the conventional chemotherapy used currently. Cedrelone is a limonoid isolated from Trichilia catigua (Meliaceae) which is a native Brazilian plant. This study demonstrates that cedrelone inhibits proliferation, adhesion, migration and invasion of breast tumor cells from the line MDA-MB-231. The effects of cell migration and invasion on MDA-MB-231 cell may be explained, at least in part, by the ability of cedrelone to inhibit MMP activity. We also demonstrate that cedrelone is able to induce apoptosis in MDA-MB-231 cells. There are only a few works investigating the effect of limonoids in cellular processes closely related to tumor progression such as adhesion, migration and invasion. To the best of our knowledge, this is the first work describing the effects of a limonoid on tumor and non-tumor cell adhesion process.

In vitro antiparasitic activity and chemical composition of the essential oil from Protium ovatum leaves (Burceraceae)

ABSTRACT Leishmaniasis and trypanosomiasis are globally widespread parasitic diseases which have been responsible for high mortality rates. Since drugs available for their treatment are highly hepatotoxic, nephrotoxic and cardiotoxic, adherence to therapy has been affected. Thus, the search for new, more effective and safer drugs for the treatment of these diseases is necessary. Natural products have stood out as an alternative to searching for new bioactive molecules with therapeutic potential. In this study, the chemical composition and antiparasitic activity of the essential oil from Protium ovatum leaves against trypomastigote forms of Trypanosoma cruzi and the promastigote forms of Leishmania amazonensis were evaluated. The essential oil was promising against trypomastigote forms of T. cruzi (IC50= 28.55 μg.mL-1) and L. amazonensis promastigotes (IC50 = 2.28 μg.mL-1). Eighteen chemical constituents were identified by Gas Chromatography coupled to Mass Spectrometry (GC-MS) in the essential oil, whose major constituents were spathulenol (17.6 %), caryophyllene oxide (16.4 %), β-caryophyllene (14.0 %) and myrcene (8.4 %). In addition, the essential oil from P. ovatum leaves had moderate cytotoxicity against LLCMK2 adherent epithelial cell at the concentration range under analysis (CC50 = 150.9 μg.mL-1). It should be highlighted that this is the first report of the chemical composition and anti-Trypanosoma cruzi and anti-Leishmania amazonensis activities of the essential oil from Protium ovatum leaves.

Evaluation of effect of triterpenes and limonoids on cell growth, cell cycle and apoptosis in human tumor cell line.

Six triterpenes and eight limonoids were evaluated for their capacity to inhibit the growth of three human tumour cell lines, breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and melanoma (A375-C5). The mechanisms involved in the observed cell growth arrest of the four most potent compounds were carried out by studying their effect in cell cycle profile and programmed cell death. The results showed that one triterpene (odoratol) and two limonoids (gedunin and cedrelone) caused cell cycle arrest while only the limonoids gedunin and cedrelone were found to be very potent inducers of apoptosis.