Antileishmanial Activity of the Essential Oils from Three Trees Obtained in Different Phenological Stages.

PURPOSE: Leishmaniasis is a parasitic disease found in tropical areas, and it affects up to 12 million individuals globally. Chemotherapies now available include drawbacks such as toxicity, high cost, and parasite resistance. This work aimed to evaluate the antileishmanial properties of essential oils (EOs) extracted from aerial parts of Cupressus sempervirens (C. sempervirens), Tetraclinis articulata (T. articulata), and Pistacia lentiscus (P. lentiscus) trees. METHODS: The EOs were obtained by hydro-distillation, and chemical composition was determined by gas chromatography coupled to mass spectrometry at three phenological stages. The EOs were evaluated in vitro for antileishmanial activities against Leishmania major (L. major) and Leishmania infantum (L. infantum). The cytotoxicity effect was also tested against murine macrophagic cells (Raw264.7 lines). RESULTS: Results showed that P. lentiscus and T. articulata EOs presented low and moderate antileishmanial activity against L. infantum and L. major. However, C. sempervirens EO from the fructification stage gave an important selectivity index (23.89 and 18.96 against L. infantum and L. major, respectively). This activity was more interesting than those of amphotericin chemical drugs. Antileishmanial activity for this EO was highly correlated with germacrene D content (r = 1.00). This compound presented a SI equal to 13.34 and 10.38 for the two strains. According to the Principal Component Analysis (PCA), the distribution of the three phenological stages proved that the chemical composition of the EOs affected the antileishmanial activity. PCA revealed that SI was positively correlated with α-pinene, germacrene D and the sesquiterpene hydrocarbon class. Cupressus sempervirens EO can provide a source of germacrene D that can be used as a new alternative to chemical drugs for the treatment of antileishmanial diseases. CONCLUSION: C. sempervirens EO seemed to be a highly active antileishmanial agent and a natural alternative for chemical drugs to treat several leishmanial strains.

Comparison of Different Extraction Methods for the Determination of Essential oils and Related Compounds from Coriander (Coriandrum sativum L.).

The volatile oil of coriander (Coriandrum sativum L.) obtained from the fruits by soxhlet-dynamic headspace (S-DHS), solvent extraction (SE), steam distillation (SD), hydrodistillation (HYD) and supercritical CO2 extraction (SC-CO2) were analyzed by GC-FID and GC-MS. The SC-CO2 offered a higher yield (4.5%, w/w) than the other used techniques. Among the identified constituents, linalool was the main compound whatever the employed extraction procedure in contrast to the remaining components which varied according to the isolation technique showing a strong effect of the method used on the composition of these minor compounds. SC-CO2 as compared to the other extraction techniques revealed its high efficiency in addition to the integrity saving of coriander fruit volatiles. Statistical analysis showed that all the detected and identified compounds were highly (P > 0.001) affected by the extraction technique used except the a-terpineol which appear stable. On the other hand, principal component analysis (PCA) revealed on the determination of one group represented by SC-CO2, S-DHS and HYD suggesting a similar essential oil composition. Obtained results show that, in Tunisian coriander essential oil, linalool was the main compound.

Salt effects on Origanum majorana fatty acid and essential oil composition.

BACKGROUND: The effects of salt on the essential oil yield and fatty acid composition of aerial parts of two marjoram varieties were investigated. Plants with 6 leaves were treated with NaCl (75mM). RESULTS: Salt treatment led to a reduction in aerial part growth. Salinity increased the fatty acid content more significantly in Tunisian variety (TV) than in Canadian variety (CV). CV showed an increase in double-bond index (DBI) and a decrease in malondialdehyde content under salt stress, while the opposite was observed in TV. The DBI was mainly affected by a strong reduction in oleic and linoleic acids in TV, whereas a strong stimulation of linoleic acid in CV was observed. Salt decreased and increased the essential oil yield in TV and CV respectively. The main constituents of the essential oil of TV were trans-hydrate sabinene and terpinen-4-ol, which showed a significant decrease under salt stress. In contrast, the main constituents of the essential oil of CV were sabinene and trans-hydrate sabinene, which showed a significant decrease and increase respectively under salt stress. CONCLUSION: Marjoram oil is a rich source of many compounds such as essential oils and fatty acids, but the distribution of these compounds differed significantly between the two varieties studied.

Essential oils and fatty acids composition of Tunisian and Indian cumin (Cuminum cyminum L.) seeds: a comparative study.

BACKGROUND: Cumin (Cuminum cyminum L.) seeds of two geographic origins, Tunisia (TCS) and India (ICS), were studied regarding their fatty acid and essential oil composition. RESULTS: Oil yields were 17.77 and 15.40% for TCS and ICS respectively. Petroselinic acid (C18:1n-12) was the major fatty acid in both varieties, with a higher proportion being found in TCS (55.90% of total fatty acids (TFA)) than in ICS (41.42% TFA). Moreover, the most predominant fatty acids were palmitic, petroselenic and linoleic acids, accounting for more than 91% TFA in both varieties. The unsaturated fatty acid content was high: 70.95% TFA in TCS and 62.17% TFA in ICS. Essential oil yields differed significantly (P < 0.05) between the two varieties: 1.21 and 1.62% for ICS and TCS respectively. A total of 40 compounds were identified, 34 of which were present in both essential oils. The two varieties displayed different chemotypes: γ-terpinene/1-phenyl-1,2-ethanediol for TCS and cuminaldheyde/γ-terpinene for ICS. CONCLUSION: The study revealed that the biochemical composition of cumin seeds is origin-dependent and that cumin seeds are rich in an unusual fatty acid, petroselinic acid. Besides, cumin essential oil is a rich source of many compounds, including cuminaldehyde and γ-terpinene. The overall results suggest the exploitation of cumin seeds as a low-cost renewable source for industrial processing in the fields of cosmetics, perfumes and pharmaceuticals.

Water-deficit impact on fatty acid and essential oil composition and antioxidant activities of cumin (Cuminum cyminum L.) aerial parts.

This study is designed to examine the effect of water deficit on growth, fatty acid and essential oil composition, and antioxidant activities of Cuminum cyminum aerial part extracts. Plants were treated with different levels of water deficit: control (C), moderate water deficit (MWD), and severe water deficit (SWD). Plant growth (height, fresh and dry matter weights) as well as yield components were significantly increased under moderate water deficit and conversely reduced at severe level. Total fatty acid content decreased significantly with severity of constraint. Drought reduced considerably the proportions of major fatty acids and the unsaturated to saturated fatty acid ratio. The essential oil yield was 0.14% (based on the dry weight); it increased by 2.21-fold at MWD but decreased by 42.8% under SWD in comparison to the control. Drought results in the modification of the essential oil chemotype from 1-phenyl-1-butanol to 1-phenyl-1,2-ethanediol. Antioxidant activities of the acetone extracts were determined by two complementary test systems, namely, DPPH and ß-carotene/linoleic acid. The highest activity was exhibited by moderately stressed plants and was reduced significantly under SWD. In control plants, the total phenolic amount was 10.23 mg GAE/g DW, which increased by 1.5-fold under MWD and decreased by 42% under SWD.

Fatty acids, essential oil, and phenolics modifications of black cumin fruit under NaCl stress conditions.

This research evaluated the effect of saline conditions on fruit yield, fatty acids, and essential oils compositions and phenolics content of black cumin (Nigella sativa). This plant is one of the most commonly found aromatics in the Mediterranean kitchen. Increasing NaCl levels to 60 mM decreased significantly the fruits yield by 58% and the total fatty acids amount by 35%. Fatty acids composition analysis indicated that linoleic acid was the major fatty acid (58.09%) followed by oleic (19.21%) and palmitic (14.77%) acids. Salinity enhanced the linoleic acid percentage but did not affect the unsaturation degree of the fatty acids pool and thus the oil quality. The essential oil yield was 0.39% based on the dry weight and increased to 0.53, 0.56, and 0.72% at 20, 40, and 60 mM NaCl. Salinity results on the modification of the essential oil chemotype from p-cymene in controls to γ-terpinene/p-cymene in salt-stressed plants. The amounts of total phenolics were lower in the treated plants. Salinity decreased mainly the amount of the major class, benzoics acids, by 24, 29, and 44% at 20, 40, and 60 mM NaCl. The results suggest that salt treatment may regulate bioactive compounds production in black cumin fruits, influencing their nutritional and industrial values.

Essential oils, phenolics, and antioxidant activities of different parts of cumin (Cuminum cyminum L.).

Cuminum cyminum L. roots, stems and leaves, and flowers were investigated for their essential oils, total phenolics, flavonoids, and tannins contents, individual phenolic compounds, and antioxidant activities. The essential oil was investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), whereas identification and quantification of individual target polyphenolic compounds was performed by reversed-phase high-performance liquid chromatography (RP-HPLC). Essential oil yields were 0.03% in roots, 0.1% in stem and leaves, and 1.7% in flowers. Major components of the oils were bornyl acetate (23%), α-terpinene (34%), and γ-terpinene (51%) in roots, stems and leaves, and flowers, respectively. In all C. cyminum organs, total phenolics content ranged from 11.8 to 19.2 mg of gallic acid equivalents per gram of dry weight (mg of GAE/g of DW). Among the polyphenols studied, 13 were identified in roots, 17 in stem and leaves, and 15 in flowers. The major phenolic compound in the roots was quercetin (26%), whereas in the stems and leaves, p-coumaric, rosmarinic, trans-2-dihydrocinnamic acids and resorcinol were predominant. In the flowers, vanillic acid was the main compound (51%). The antioxidant activities of C. cyminum essential oils and acetone extracts obtained from the three organs were assessed using four tests [1,1-diphenyl-2-picrylhydrazyl (DPPH), ß-carotene/linoleic acid, reducing power, and chelating power assays]. The acetone extract of flowers was strongly effective as a DPPH radical scavenger, lipid peroxidation inhibitor, and reducing agent, with IC(50) values of 4, 32, and 8 µg/mL, respectively. Moreover, the acetone extract of stems and leaves showed the highest chelating power. However, the essential oils exhibited moderate activities in the different tests.