Nicolas Baldovini

Anticancer Activities of Essential Oils Constituents and Synergy with Conventional Therapies: A Review

Many studies have shown that a large number of terpenoids and aromatic compounds contained in essential oils have significant anticancer activities, both on cell lines and on tumors in animals. The activity of these constituents is related to the activation of cell death (apoptosis) induced by the caspases proteins in cancer cells, with minor modifications of healthy cells. Many phenomena seem to occur, among which are as follows: overexpression and regulation of liver detoxification enzymes, changes in the membrane potential of cancer cells and mitochondria, production of free radicals in cancer cells, inhibition of angiogenesis, and modification of tumor‐inducing genes. These active essential oil constituents appear to act synergistically with conventional chemotherapy and radiotherapy, and some clinical studies in humans are beginning to be realized. In this review, we discuss about the antitumoral activity of 13 essential oil components selected among the most studied in the literature, with a focus on their possible mode of action. We also report current data on the anticancer properties of several total essential oils. Copyright

Identification and quantitative determination of furanodiene, a heat-sensitive compound, in essential oil by 13C-NMR.

A method based on 13C-NMR has been used as a tool for the identification and quantitative determination of two furanic sesquiterpenes: a heat-sensitive compound, furanodiene, and its rearrangement product, furanoelemene. Following a preliminary study using artificial mixtures which permitted the construction and verification of calibration curves for each compound, the method was used for the qualitative and quantitative analysis of furanodiene and furanoelemene in the essential oil of Smyrnium olusatrum.

Qualitative and quantitative analysis of vetiver essential oils by comprehensive two-dimensional gas chromatography and comprehensive two-dimensional gas chromatography/mass spectrometry.

Vetiver essential oils (VEO) are important raw ingredients used in perfume industry, entering the formula of numerous modern fragrances. Vetiver oils are considered to be among the most complex essential oils, resulting most of the time in highly coeluted chromatograms whatever the analytical technique. In this context, conventional gas chromatography has failed to provide a routine tool for the accurate qualitative and quantitative analysis of their constituents. Applying comprehensive two-dimensional gas chromatography techniques (GC×GC-FID/MS) afforded the mean to separate efficiently vetiver oil constituents in order to identify them in a more reliable way. Moreover, this is the first time that a complete true quantitation of each constituent is carried out on such complex oils by means of internal calibration. Finally, we have studied the influence of the injection mode on the determined chemical composition, and showed that several alcohols underwent dehydration under defined chromatographic conditions (splitless mode) usually recommended for quantitation purposes.

Bioactive phenylpropanoids from Daucus crinitus Desf. from Algeria.

The volatile constituents of Daucus crinitus Desf. from Algeria were analyzed by GC and GC-MS, The main constituent was isochavicol isobutyrate (39.0%), an uncommon phenylpropanoid. By synthesis of a series of homologous esters, it was also possible to determine the presence of small amounts of isochavicol propionate, which has never been described previously as a natural product. The antibacterial and antifungal activities of the whole essential oil, of these two esters, and of isochavicol itself were investigated against a wide range of bacteria and fungi. Additionally, their antimalarial and antiradical properties were also evaluated, showing an interesting antiplasmodial activity of isochavicol.

Infraspecific variability of the essential oil of Calamintha nepeta from Corsica (France)

The chemical composition of 40 samples of essential oil of Calamintha nepeta, growing wild in Corsica, was examined. After a preliminary study on a single plant, which allowed definition of the full blossom as the stable period for harvesting, the existence of three chemotypes was demonstrated. Half of the samples were characterized by a menthone/pulegone chemotype, 13 samples present pulegone as the major component associated with menthone, while piperitone and piperitenone oxides were the main components of the last 11 samples. Copyright

An antibacterial and antifungal phenylpropanoid from Carum montanum (Coss. et Dur.) Benth. et Hook.

The volatile constituents of the aerial parts of Carum montanum (Coss. et Dur.) Benth. et Hook. were analysed by GC‐FID and GC‐MS, and the main component was isolated and identified as nothoapiole. The antibacterial and antifungal activities of this compound and of the total oil were investigated against Gram‐negative (P. aeruginosa, E. coli), Gram‐positive (E. faecalis, S. aureus, S. epidermitis, S. saprophyticus, S. simulans, S. lugdunensis) bacteria and on one strain of fungus (C. tropicalis). Copyright

Chemical composition of French mimosa absolute oil.

Since decades mimosa (Acacia dealbata) absolute oil has been used in the flavor and perfume industry. Today, it finds an application in over 80 perfumes, and its worldwide industrial production is estimated five tons per year. Here we report on the chemical composition of French mimosa absolute oil. Straight-chain analogues from C6 to C26 with different functional groups (hydrocarbons, esters, aldehydes, diethyl acetals, alcohols, and ketones) were identified in the volatile fraction. Most of them are long-chain molecules: (Z)-heptadec-8-ene, heptadecane, nonadecane, and palmitic acid are the most abundant, and constituents such as 2-phenethyl alcohol, methyl anisate, and ethyl palmitate are present in smaller amounts. The heavier constituents were mainly triterpenoids such as lupenone and lupeol, which were identified as two of the main components. (Z)-Heptadec-8-ene, lupenone, and lupeol were quantified by GC-MS in SIM mode using external standards and represents 6%, 20%, and 7.8% (w/w) of the absolute oil. Moreover, odorant compounds were extracted by SPME and analyzed by GC-sniffing leading to the perception of 57 odorant zones, of which 37 compounds were identified by their odorant description, mass spectrum, retention index, and injection of the reference compound.

Activity of Ocimum basilicum, Ocimum canum, and Cymbopogon citratus essential oils against Plasmodium falciparum and mature-stage larvae of Anopheles funestus s.s.

The biological activities of essential oils from three plants grown in Cameroon: Ocimum basilicum, Ocimum canum, and Cymbopogon citratus were tested against Plasmodium falciparum and mature-stage larvae of Anopheles funestus. Gas chromatography and gas chromatography – mass spectrometry analyses showed that the main compounds are geranial, 1,8-cineole and linalool in C. citratus, O. canum and O. basilicum, respectively. Larvicidal tests carried out according to the protocol recommended by the World Health Organization showed that the essential oil of leaves of C. citratus is the most active against larvae of An. funestus (LC50 values = 35.5 ppm and 34.6 ppm, respectively, for larval stages III and IV after 6 h of exposure). Besides, the in vitro anti-plasmodial activity evaluated by the radioisotopic method showed that the C. citratus oil is the most active against P. falciparum, with an IC50 value of 4.2 ± 0.5 μg/mL compared with O. canum (20.6 ± 3.4 μg/mL) and O. basilicum (21 ± 4.6 μg/mL). These essential oils can be recommended for the development of natural biocides for fighting the larvae of malaria vectors and for the isolation of natural products with anti-malarial activity.

Multidimensional analysis of cannabis volatile constituents: identification of 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane as a volatile marker of hashish, the resin of Cannabis sativa L.

The volatile constituents of drug samples derived from Cannabis sativa L. were investigated by means of headspace solid phase microextraction (HS-SPME) and gas chromatography techniques (GC-MS, GC×GC-MS). Samples of cannabis herb and hashish showed clear differences in their volatile chemical profiles, mostly resulting from photo-oxidation processes occurring during the transformation of fresh cannabis herb into hashish. Most unexpectedly, we could demonstrate hashish samples as containing remarkable amounts of a rare and unusual monoterpene - 5,5-dimethyl-1-vinylbicyclo[2.1.1]hexane - among the volatile compounds detected in their headspaces. We gave evidence for the formation of this compound from the light induced rearrangement of β-myrcene during the manufacture of hashish. In view of its high abundance among volatile constituents of cannabis resin and its scarce occurrence in other natural volatile extracts, we propose to rename this specific monoterpene hashishene.

Unravelling the scent of vetiver: identification of character-impact compounds.

Vetiver oil is a highly esteemed basic ingredient of modern perfumery, but the nature of the constituents that really impart its typical and most sought woody‐earthy scent has remained controversial. Indeed, vetiver oil is considered as one of the most complex essential oils, being mostly composed of several hundreds of sesquiterpene derivatives with a large structural diversity. Its complexity has hindered the direct identification of its odoriferous components. We thus aimed at using a combination of GC×GC/MS and GC‐Olfactometry in order to identify most of its odor‐impact constituents. The olfactory analysis of vetiver oil and vetiveryl acetate revealed a huge variety of odors in both products. While khusimone has almost unanimously been recognized as the most characteristic vetiver odorant, we have identified several even more important contributors to the typical vetiver character.