Composition and biological activities of the essential oil from a Sicilian accession of Prangos ferulacea (L.) Lindl.

Prangos ferulacea (L.) Lindl. (Fam. Apiaceae), is an orophilous species of eastern Mediterranean and western Asia which possesses several biological properties, which are worthy of exploitation in different fields. With the aim to provide new insights into the phytochemistry and pharmacology of this species, a local accession growing in Sicily (South Italy) was investigated as well. Notably, the P. ferulacea essential oil chemical composition and the antioxidant, anti-acetylcholinesterase (AChE) and cytotoxic activities have been studied. This analysis allowed to identify a new chemotype and to report good biological results for this oil.

Chemical Composition and Antiproliferative Effect of Essential Oils of Four Solidago Species (S. canadensis, S. gigantea, S. virgaurea and S.×niederederi).

There is a growing interest in the research of natural products with potent activity in the prevention and treatment of diseases. Thereby, essential oil phytochemicals have demonstrated broad bioactivities. This study highlights the chemical composition of essential oils obtained from the leaves and inflorescences of diverse species of the genus Solidago (Solidago canadensis, Solidago gigantea, Solidago virgaurea and Solidago×niederederi), also known as Goldenrod, through GC/MS analysis, and their antiproliferative activity on three human tumor cell lines (MDA-MB 231, A375 and HCT116) by the MTT assay. The most represented chemical classes in the essential oils were oxygenated sesquiterpenes, sesquiterpene hydrocarbons, oxygenated monoterpenes and monoterpene hydrocarbons, with a remarkable contribution of compounds such as germacrene D (3.89-19.51 %), α-pinene (3.59-18.82 %), bornyl acetate (3.30-12.73 %) and caryophyllene oxide (3.07-9.18 %). Chemical quali- and quantitative differences were noticed between the leaves and flowers of the same species, as well as between the studied species. The MTT assay showed that the essential oils from the leaves were more active than those from the flower ones. The essential oil having the highest impact on cell viability was that from S.×niederederi (IC50 =12.93, 6.72, and 6.82 µg/ml), followed by S. virgaurea (IC50 =13.39, 7.96, and 8.36 µg/ml) and finally S. gigantea (IC50 =18.04, 5.94, and 8.10 µg/ml) on MDA-MB 231, A375 and HCT116 cell lines, respectively. The essential oil from S. canadensis showed the lowest activity (IC50 =29.33, 12.63, and 18.03 µg/ml, respectively). Taken together, these findings highlight the Solidago species as good sources of cytotoxic compounds. Further studies are encouraged on the in vivo effects and safety of these products.

Hairy Garlic (Allium subhirsutum) from Sicily (Italy): LC-DAD-MSn Analysis of Secondary Metabolites and In Vitro Biological Properties.

Allium subhirsutum, known as hairy garlic, is a bulbous plant widespread in the Mediterranean area and locally used as a food and spice. In the present study, the chemical profile of the ethanolic extracts from bulbs (BE) and aerial parts (APE) were analyzed by HPLC-ESI-MSn, and antioxidant properties were evaluated by DPPH, ABTS and TEAC assays. The traditional use in the diet, and the well documented biological activity of Allium species suggest a potential as a new nutraceutical. For this reason, the potential usefulness of this food can be considered in the treatment and prevention of degenerative Alzheimer disease. For this reason, acetylcholinesterase inhibitory property was investigated. Furthermore, due to the observed presence of sulfur-containing and phenolic constituents, the cytotoxicity on tumor cells line was investigated. Results revealed significant AChE inhibitory activity for BE and APE. Both extracts exhibited also moderate antioxidant properties in the in vitro assays. Finally, limited cytotoxic activity was observed towards Human colon carcinoma and adenocarcinoma cell line, with differences between the individual parts tested. HPLC-ESI-MSn analysis showed that hairy garlic is a good source of sulphur compounds, flavonoids and phenylpropanoids derivatives, thus being a valid alternative to the common garlic (A. sativum). This work opens new opportunities for the application of A. subhirsutum as a health-promoting food.

The volatile oils from the oleo-gum-resins of Ferula assa-foetida and Ferula gummosa: A comprehensive investigation of their insecticidal activity and eco-toxicological effects.

Since time immemorial, the oleo-gum-resins of Ferula assa-foetida and F. gummosa are used in the traditional medical systems as well as in foodstuffs, perfumery and cosmetics. In the present study, we explored the insecticidal efficacy of the essential oils obtained from these oleo-gum-resins to widen their fields of industrial applications. The two essential oils were mainly composed of sulfides [sec-butyl (Z)-propenyl disulfide, sec-butyl (E)-propenyl disulfide, sec-butyl (Z)-propenyl trisulfide and sec-butyl (E)-propenyl trisulfide)] and monoterpenes (α-pinene, ß-pinene and ß-phellandrene), respectively, as determined by GC-MS analysis. The two essential oils were assayed for toxicity on a panel of insects, represented by species of public health relevance (Culex quinquefasciatus and Musca domestica), agricultural (Spodoptera littoralis) and stored-product pests (Prostephanus truncatus and Trogoderma granarium). The ecotoxicological effects of the essential oils were assessed on the aquatic microcrustacean Daphnia magna and the earthworm Eisenia fetida, as well as on human cells. Overall, the two essential oils were effective against important insect pests and vectors. On the other hand, they resulted cytotoxic to fibroblasts and non-target aquatic microcrustaceans. Thus, further insights are needed to determine the full spectrum of their eco-toxicological effects.

Exploring new applications of tulip tree (Liriodendron tulipifera L.): leaf essential oil as apoptotic agent for human glioblastoma.

Liriodendron tulipifera L. (Magnoliaceae), also known as "tulip tree," is a hardwood plant native to North America, cultivated all over the world and used on an industrial level, especially for its fine wood and to make honey. It has also been traditionally exploited for its antimalarial properties. However, our knowledge about the bioactivity of its essential oil remains patchy. In this research, we focused on the biological evaluation of the volatile fractions obtained from different parts of the plant which are normally discharged by industry, including leaves, flowers, and fruits. For the purpose, the essential oils were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). Then, they were evaluated as radical scavenging, antioxidant, antimicrobial, and antiproliferative agents by using DPPH, ABTS, FRAP, disk diffusion, and MTT methods, respectively. The significant toxicity exhibited on human tumor cells, namely A375 malignant melanoma, HCT116 colon carcinoma, MDA-MB 231 breast adenocarcinoma, and T98G glioblastoma multiforme cell lines, prompted us to study the mechanism of action by acridine orange/ethidium bromide double staining and caspase 3 assays. Our findings shed light on the potential applications of tulip tree derivatives as anticancer drugs.

The Nonvolatile and Volatile Metabolites of Prangos ferulacea and Their Biological Properties.

Prangos ferulacea (L.) Lindl. (Fam. Apiaceae), an orophilous species of eastern Mediterranean and western Asia, possesses a number of biological properties that are worthy of exploitation in different fields. Phytochemical investigations revealed the presence of coumarins, prenyl-coumarins, and furano-coumarins as the main constituents of this species, as well as several flavonoids. Among prenyl-coumarins, osthol is a promising apoptotic agent quite selective toward cancer cells. In addition, the essential oils have been extensively investigated, and several chemotypes have been identified. This work reviews the literature on this species published between 1965 and 2018, describes its volatile and nonvolatile metabolites, and outlines its pharmacological effects.

Steroidal saponins from the aerial parts of Cordyline fruticosa L. var. strawberries.

A new sulfated steroidal derivative (fruticogenin A: 1-sulfo-australigenin-3-sodium sulphate, 1) and three new steroidal saponins named fruticoside K (3-sulfo-spirostan-25(27)-ene-1ß,3ß-diol-1-O-[α-L-rhamnopyranosyl-(1 → 4)-ß-D-fucopyranoside], 2), fruticoside L (3-sulfo-spirostan-25(27)-ene-1ß,3ß,6α-triol-1-O-[α-L-rhamnopyranosyl-(1 → 4)-ß-D-fucopyranoside], 3) and fruticoside M (spirostan-25(27)-ene-1ß,3α-diol-1-O-[α-L-rhamnopyranosyl-(1 → 2)-α-L-rhamnopyranoside], 4) were isolated from the aerial parts of Cordyline fruticosa L. var. strawberries. Their structures were established on the basis of 1D and 2D NMR data, mass spectrometry and chemical methods. Compounds 2 and 4 exhibited weak cytotoxicity against melanoma (A375), breast adenocarcinoma (MDA-MB-231), and colon carcinoma (HCT116) human tumor cell lines.

Chemical composition, antioxidant activity and cytotoxicity on tumour cells of the essential oil from flowers of Magnolia grandiflora cultivated in Iran.

Magnolia grandiflora (Magnoliaceae) is an evergreen tree with fragrant and showy flowers native to southeastern USA but widely cultivated all over the world and used in cosmetics industry in treatment of skin diseases. Here, we report on the chemical analysis of the essential oil obtained from flowers of plants cultivated in Iran, together with the evaluation of its antioxidant and cytotoxic activities. The essential oil composition was dominated by bioactive sesquiterpenes, namely ß-elemene, bicyclogermacrene, germacrene D and (E)-caryophyllene. The oil exhibited moderate radical scavenging activity towards the [Formula: see text] radical, and mild non-selective inhibitory effects against A375, MDA-MB 231 and T98 G tumour cell lines. The latter were influenced by the presence of the anticancer ß-elemene. These results provided new insights for potential application of M. grandiflora volatile oil in the pharmaceutical and cosmetics industry where only the non-volatile magnolol and honokiol have hitherto been fully exploited.

Phytochemical investigations and antiproliferative secondary metabolites from Thymus alternans growing in Slovakia.

CONTEXT: Thymus alternans Klokov (Lamiaceae) is a neglected species of the genus Thymus (Sect. Serpyllum) endemic to Carpathian area, where it is used as a flavouring agent and for medicinal purposes. OBJECTIVE: The aim of the work was to identify antiproliferative constituents from the flowering aerial parts of this plant. MATERIALS AND METHODS: Thymus alternans extracts were analyzed by HPLC-MSn and subjected to extensive chromatographic separations. The isolated compounds (phenolics and triterpenes) were structurally elucidated by MS and 1D and 2D NMR experiments. Essential oil (EO) composition was determined by GC-FID and GC-MS. Six purified triterpenes and EO were assayed for in vitro antiproliferative activity against a panel of human cancer cells, namely, breast (MDA-MB 231), colon (HCT-15 and HCT116), lung (U1810), pancreatic (BxPC3), melanoma (A375) and cervical carcinoma (A431) cells. RESULTS: The structures of the isolated compounds were achieved on the basis of H-NMR and MS experiments. Luteolin-4'-O-ß-d-glucopyranoside (P1), chrysoeriol-7-O-ß-d-glucopyranoside (P2), chrysoeriol-5-O-ß-d-glucopyranoside (P3), apigenin-7-O-ß-d-glucopyranoside (P4), rosmarinic acid (P5), rosmarinic acid-3'-O-ß-d-glucopyranoside (P6), caffeic acid-3-O-ß-d-glucopyranoside (P7), 3α-hydroxy-urs-12,15-diene (T1), α-amyrin (T2), ß-amyrin (T3), isoursenol (T4), epitaraxerol (T5), and oleanolic acid (T6). GC-MS analysis revealed that the EO of T. alternans was devoid of phenols and belonged to the nerolidol-chemotype, that is typical of the Sect. Serpyllum. The six purified triterpenes (T1-T6) were active with IC50 ranging from 0.5 to 5 µM being comparable or better than those of reference compounds betulinic acid and cisplatin. The EO exhibited significant effects on A375, MDA-MB 231 and HCT116 cell lines with IC50 in the range of 5-8 µg/mL. CONCLUSION: The reported results suggest that T. alternans can be considered as a good source of phytoconstituents with possible importance in the pharmaceutical field.

Stabilization of the cyclodecadiene derivative isofuranodiene by silver (I) coordination. Mechanistic and biological aspects.

The industrial extraction and further applications of isofuranodiene are limited because at room temperature it spontaneously converts to curzerene, a structurally less active isomer. This work definitively identified the structure of isofuranodiene in the solid state, showing the two methyl groups in syn position. In addition, two bioactive metal cations, namely, silver(I) and copper(II) ions, were used in the attempt to obtain the chemical stability of isofuranodiene: in the case of silver(I), a labile adduct was formed, while in the case of copper(II), a more stable 1:1 adduct was achieved. In the former, the presence of silver did not significantly affect the biological activities of isofuranodiene, while in the latter, the copper(II) coordination suppressed them. The biological activities of the isofuranodiene adducts were then evaluated as antiproliferative agents against human tumor cell lines (HCT116, MDA-MB 231, and T98G). In addition, for the first time, isofuranodiene was tested as an inhibitor of DHFR (DiHydroFolateReductase) from Escherichia coli. Anticancer activity was observed in the isofuranodiene with the AgCF3SO3 adduct, in the tested cell lines, with IC50 values ranging from 4.89µM to 13.06µM, while inhibition assays highlighted a Ki of 6.22µM for isofuranodiene and of 0.17µM for the related silver adduct. Docking studies indicated a binding mode score of -6.83Kcal/mol for isofuranodiene, and an energy value of -11.82Kcal/mol for methotrexate (a classic DHFR inhibitor).

Rosmarinus eriocalyx: An alternative to Rosmarinus officinalis as a source of antioxidant compounds.

Rosmarinus eriocalyx is an aromatic evergreen bush endemic to Algeria where it is used as a condiment to flavour soups and meat and as a traditional remedy. In the present work we have analyzed for the first time the phenolic composition of polar extracts obtained from stems, leaves and flowers of R. eriocalyx by HPLC, and determined the antioxidant and antimicrobial effects by DPPH, ABTS, FRAP, ORAC and agar disc diffusion methods, respectively. Results showed that ethanolic extracts of leaves and flowers are a rich source of phenolic compounds, mainly rosmarinic acid, carnosic acid and carnosol that are the main responsible for the noteworthy antioxidant activity observed in the assays. This study showed that R. eriocalyx might be a spice to be included in the European food additive list and used as a preservative agent besides R. officinalis.

Phenolic acids, antioxidant and antiproliferative activities of Naviglio® extracts from Schizogyne sericea (Asteraceae).

Schizogyne sericea, well-known as 'salado', is a halophytic shrub widespread on coastal rocks of Tenerife (Canary Islands). This plant is used traditionally as analgesic, astringent, anti-inflammatory and vulnerary agent. In the present work, we have analysed the aqueous and ethanolic extracts of S. sericea for the content of phenolic acids by HPLC-DAD. The dynamic solid-liquid Naviglio® extractor was used to extract the flowering aerial parts. Aqueous extracts showed higher levels of phenolics than ethanolic extracts. S. sericea extracts were rich in chlorogenic and isochlorogenic acids. The Naviglio® extracts obtained were assayed for in vitro biological activities, namely antioxidant, antimicrobial and cytotoxicity on tumour cells by DPPH, ABTS, FRAP, agar disc-diffusion and MTT methods, respectively. Results showed that aqueous extracts, being richer in phenolic acids, are endowed with relevant radical scavenging activity (TEAC values in the range 208-960 µmol TE/g) while ethanolic extracts exhibited noteworthy antiproliferative effects on tumour cells.

In vitro and ex vivo activity of an Azadirachta indica A.Juss. seed kernel extract on early sporogonic development of Plasmodium in comparison with azadirachtin A, its most abundant constituent.

BACKGROUND: NeemAzal® (NA) is a quantified extract from seed kernels of neem, Azadirachta indica A.Juss. (Meliaceae), with a wide spectrum of biological properties, classically ascribed to its limonoid content. NA contains several azadirachtins (A to L), azadirachtin A (AzaA) being its main constituent. AzaA has been shown to inhibit microgamete formation of the rodent malaria parasite Plasmodium berghei, and NA was found to completely inhibit the transmission of Plasmodium berghei to Anopheles stephensi mosquitoes when administered to gametocytemic mice at a corresponding AzaA dose of 50mg/kg before exposure to mosquitoes. PURPOSE: The present study was aimed at i) assessing the pharmacodynamics and duration of action of NA and AzaA against P. berghei exflagellation in systemic circulation in mice and ii) elucidating the transmission blocking activity (TBA) of the main NA constituents. STUDY DESIGN: The NA and AzaA pharmacodynamics on exflagellation were assessed through ex vivo exflagellation assays, while TBA of NA constituents was evaluated through in vitro ookinete development assay. METHODS: Pharmacodynamics experiments: Peripheral blood from P. berghei infected BALB/c mice with circulating mature gametocytes, were treated i.p. with 50mg/kg and 100mg/kg pure AzaA and with NeemAzal® (Trifolio-M GmbH) at the corresponding AzaA concentrations. The effect magnitude and duration of action of compounds was estimated by counting exflagellation centers, formed by microgametocytes in process of releasing flagellated gametes, at various time points after treatment in ex vivo exflagellation tests. Ookinete Development Assay: The direct effects of NeemAzal® and AzaA on ookinete development were measured by fluorescence microscopy after incubation of gametocytemic blood with various concentrations of test substances in microplates for 24h. RESULTS: The exflagellation tests revealed an half-life of NA anti-plasmodial compounds of up to 7h at a NA dose corresponding to 100mg/kg equivalent dose of AzaA. The ookinete development assay showed an increased activity of NA against early sporogonic stages compared to that of AzaA. The IC50 value determined for NA was 6.8µg/ml (CI95: 5.95-7.86), about half of the AzaA IC50 (12.4µg/ml; CI95: 11.0-14.04). CONCLUSION: The stronger activity of NA, when compared to AzaA, could not be explained by an additive or synergistic effect by other azadirachtins (B, D and I) present in NA. In fact, the addition of these compounds at 50µM concentration to AzaA did not evidence any decrease of the IC50 against early sporogonic stages to that obtained with AzaA alone. It is likely that other non-limonoid compounds present in NA may contribute to AzaA activity and enhanced pharmacodynamics against exflagellation both in vitro and in vivo.

Biological Activities of the Essential Oil from Erigeron floribundus.

Erigeron floribundus (Asteraceae) is an herbaceous plant widely used in Cameroonian traditional medicine to treat various diseases of microbial and non-microbial origin. In the present study, we evaluated the in vitro biological activities displayed by the essential oil obtained from the aerial parts of E. floribundus, namely the antioxidant, antimicrobial and antiproliferative activities. Moreover, we investigated the inhibitory effects of E. floribundus essential oil on nicotinate mononucleotide adenylyltransferase (NadD), a promising new target for developing novel antibiotics, and Trypanosoma brucei, the protozoan parasite responsible for Human African trypanosomiasis. The essential oil composition was dominated by spathulenol (12.2%), caryophyllene oxide (12.4%) and limonene (8.8%). The E. floribundus oil showed a good activity against Staphylococcus aureus (inhibition zone diameter, IZD of 14 mm, minimum inhibitory concentration, MIC of 512 µg/mL). Interestingly, it inhibited the NadD enzyme from S. aureus (IC50 of 98 µg/mL), with no effects on mammalian orthologue enzymes. In addition, T. brucei proliferation was inhibited with IC50 values of 33.5 µg/mL with the essential oil and 5.6 µg/mL with the active component limonene. The essential oil exhibited strong cytotoxicity on HCT 116 colon carcinoma cells with an IC50 value of 14.89 µg/mL, and remarkable ferric reducing antioxidant power (tocopherol-equivalent antioxidant capacity, TEAC = 411.9 µmol·TE/g).

Blue honeysuckle fruit (Lonicera caerulea L.) from eastern Russia: phenolic composition, nutritional value and biological activities of its polar extracts.

In the present work we conducted a comprehensive chemical analysis of blue honeysuckle (Lonicera caerulea) spontaneously growing in eastern Russia. HPLC-DAD-ESI/MS analysis showed cyanidin-3-glucoside as the major constituent among phenolics, while nutritional analysis revealed fibre, protein, calcium and magnesium as the most important macro- and micronutrients, respectively. Fatty acid composition was dominated by polyunsaturated fatty acids, linoleic acid being the most abundant. Furthermore, we evaluated several in vitro biological activities such as antioxidant, antimicrobial, antiproliferative, wound healing and immunomodulatory effects of blue honeysuckle aqueous and ethanolic extracts that are often incorporated in food and nutraceutical preparations. While the fruit extracts were revealed to be potent radical scavengers with significant inhibition of ABTS radical, thus confirming the literature data, their inhibitory effects against microbial pathogens and tumor cell lines were negligible. The fruit aqueous extract did not show toxicity to human fibroblasts, but 24 h treatment with 150-200 µg per mL of extract slightly enhanced the cell migration when tested by scratched wound assay. Worth mentioning was the inhibitory effect displayed by the blue honeysuckle fruit aqueous extract on human lymphocytes.

Essential oil composition and biological activity from Artemisia caerulescens subsp. densiflora (Viv.) Gamisans ex Kerguélen & Lambinon (Asteraceae), an endemic species in the habitat of La Maddalena Archipelago.

The purpose of this study was to investigate the composition of the essential oil obtained from a population of Artemisia caerulescens subsp. densiflora growing in Razzoli, an island in the La Maddalena Archipelago (Sardinia, Italy). A. caerulescens sups. densiflora Viv. (Asteraceae), a wild herb, seldom studied in the Mediterranean, represents one of the many rare endemic species growing in North Sardinia. The essential oil composition was analysed by means of GC/MS analysis, which showed davana ethers as the major volatile components, accounting together for 17.5%, followed by (E)-nerolidol (4.5%), ß-oplopenone (3.3%), cis-sabinene hydrate (5.2%) and terpinen-4-ol (4.7%). The oil was tested for antioxidant activity by means of DPPH test, inhibition of lipid oxidation test and hypochlorous acid test, which showed a quite interesting scavenger capacity. For the first time, we reported the cytotoxic activity of the essential oil of A. caerulescens subsp. densiflora, against three human tumour cell lines (A375, MDA-MB231 and HCT116), with IC50 values in the range 5.20-7.61 µg/mL, which deserved further studies to support its use as chemopreventive agent. Finally, the antimicrobial activity of the essential oil, displayed on a panel of human pathogens, was very low.

Phytochemical Analysis, Biological Activity, and Secretory Structures of Stachys annua (L.) L. subsp. annua (Lamiaceae) from Central Italy.

Stachys annua subsp. annua, well-known in central Italy as 'stregona annuale', is an annual, small, slightly-scented herb, commonly found in fields and uncultivated areas in almost all regions of Italy. In folk medicine, its aerial parts were used as anti-catarrhal, febrifuge, tonic, and vulnerary. In the present work, the chemical composition of the flowering aerial parts was studied. The hydrodistilled volatile oil, analysed by GC/MS, showed sesquiterpenoids as the major fraction (42.5%); phytol (9.8%), germacrene D (9.2%), and spathulenol (8.5%) were the most abundant constituents. The volatile oil was assayed for antioxidant and cytotoxic activity by DPPH, ABTS, FRAP, and MTT methods. The cytotoxicity results against HCT116, A375, and MDA-MB 231 human tumor cell lines were significant, with IC50 values of 23.5, 37.2, and 41.5 µg/ml, respectively, whereas the antioxidant power was negligible. The EtOH extract was composed mainly of three glycosidic flavonoids, namely 7-{[2-O-(6-O-acetyl-ß-D-allopyranosyl)-ß-D-glucopyranosyl]oxy}-5,8-dihydroxy-2-(4-methoxyphenyl)-4H-1-benzopyran-4-one (1), 7-{[6-O-acetyl-2-O-(6-O-acetyl-ß-D-allopyranosyl)-ß-D-glucopyranosyl]oxy}-2-(3,4-dihydroxyphenyl)-5,8-dihydroxy-4H-1-benzopyran-4-one (2), and 7-{[6-O-acetyl-2-O-(ß-D-allopyranosyl)-ß-D-glucopyranosyl]oxy}-2-(3-hydroxy-4-methoxyphenyl)-5,8-dihydroxy-4H-1-benzopyran-4-one (3). On the contrary, iridoids, considered chemotaxonomic markers of the genus Stachys, were absent in this species. Finally, the morphological and histochemical survey showed that glandular trichomes were composed of two main types, i.e. peltate type A and capitate types B and C giving positive response for both lipids and polyphenols.

Plasmodium transmission blocking activities of Vernonia amygdalina extracts and isolated compounds.

BACKGROUND: Medicinal plants are a validated source for discovery of new leads and standardized herbal medicines. The aim of this study was to assess the activity of Vernonia amygdalina leaf extracts and isolated compounds against gametocytes and sporogonic stages of Plasmodium berghei and to validate the findings on field isolates of Plasmodium falciparum. METHODS: Aqueous (Ver-H2O) and ethanolic (Ver-EtOH) leaf extracts were tested in vivo for activity against sexual and asexual blood stage P. berghei parasites. In vivo transmission blocking effects of Ver-EtOH and Ver-H2O were estimated by assessing P. berghei oocyst prevalence and density in Anopheles stephensi mosquitoes. Activity targeting early sporogonic stages (ESS), namely gametes, zygotes and ookinetes was assessed in vitro using P. berghei CTRPp.GFP strain. Bioassay guided fractionation was performed to characterize V. amygdalina fractions and molecules for anti-ESS activity. Fractions active against ESS of the murine parasite were tested for ex vivo transmission blocking activity on P. falciparum field isolates. Cytotoxic effects of extracts and isolated compounds vernolide and vernodalol were evaluated on the human cell lines HCT116 and EA.hy926. RESULTS: Ver-H2O reduced the P. berghei macrogametocyte density in mice by about 50% and Ver-EtOH reduced P. berghei oocyst prevalence and density by 27 and 90%, respectively, in An. stephensi mosquitoes. Ver-EtOH inhibited almost completely (>90%) ESS development in vitro at 50 µg/mL. At this concentration, four fractions obtained from the ethylacetate phase of the methanol extract displayed inhibitory activity >90% against ESS. Three tested fractions were also found active against field isolates of the human parasite P. falciparum, reducing oocyst prevalence in Anopheles coluzzii mosquitoes to one-half and oocyst density to one-fourth of controls. The molecules and fractions displayed considerable cytotoxicity on the two tested cell-lines. CONCLUSIONS: Vernonia amygdalina leaves contain molecules affecting multiple stages of Plasmodium, evidencing its potential for drug discovery. Chemical modification of the identified hit molecules, in particular vernodalol, could generate a library of druggable sesquiterpene lactones. The development of a multistage phytomedicine designed as preventive treatment to complement existing malaria control tools appears a challenging but feasible goal.

Antioxidant activity and cytotoxicity on tumour cells of the essential oil from Cedronella canariensis var. canariensis (L.) Webb & Berthel. (Lamiaceae).

Cedronella canariensis is a lemon-scented species of the family Lamiaceae endemic to the Canary Islands where it is used in the traditional medicine to prepare infusions or inhalations for anti-catarrhal, tonic, diuretic, hypoglycaemiant, hypotensive, anti-inflammatory and decongestant of the respiratory tract. In this work we investigated for the first time the antioxidant activity of the essential oil and its inhibitory effects on tumour cells (A375, MDA-MB-231, HCT 116) proliferation by DPPH, ABTS, FRAP and MTT assays, respectively. The oil, analysed by GC-ionisation flame detector and GC-MS, was characterised by pinocarvone (58.0%) and ß-pinene (10.8%) as the major constituents, being typical of the chemotype 'canariensis'. Noteworthy was the cytotoxic activity of the oil against the tumour cells examined, with IC50 values of 4.3, 7.3 and 11.4 µg/mL on A375, MDA-MB-231 and HCT 116 tumour cells, respectively, as well as the scavenging activity against the ABTS radical (IC50 of 10.5 µg/mL).

Phytochemical analysis and in vitro biological activity of three Hypericum species from the Canary Islands (Hypericum reflexum, Hypericum canariense and Hypericum grandifolium).

In the present work we carried out a phytochemical and biological investigation on three Hypericum species, i.e. Hypericum reflexum, Hypericum canariense and Hypericum grandifolium, from the Canary Islands where they are traditionally used as diuretic, wound healing, vermifuge, sedative and antidepressive agents. The polar extracts of the top flowering aerial parts, prepared by Soxhlet apparatus using a methanol-acetone (1:1) extracting mixture, were analyzed by HPLC-DAD and HPLC-MS for the content of eight biomarkers such as hypericin, hyperforin, chlorogenic acid, rutin, hyperoside, isoquercitrin, quercitrin and quercetin, whereas the hydrodistilled essential oils were analyzed by GC-FID and GC-MS. The three Hypericum species had different results in both polar and volatile constituents, H. reflexum being the only one endowed with a small amount of naphtodianthrones (hypericin and pseudohypericin), and containing high levels of chlorogenic acid, rutin and volatile mono- and sesquiterpenes. After chemical characterization, all products were in vitro biologically assayed for antiproliferative activity on human tumor cell lines by MTT assay, for antioxidant potential by DPPH, ABTS and FRAP assays, and for antimicrobial activity by the agar disc diffusion and microdilution methods. Results revealed interesting bioactivities and differences between polar extracts and essential oils, with the former being endowed with significant antioxidant activity and the latter with comparable inhibition effects on the tumor cells (A375, MDA-MB 231 and HCT 116) to that of cisplatin.