Conyza canadensis from Jordan: Phytochemical Profiling, Antioxidant, and Antimicrobial Activity Evaluation.

In this investigation, the chemical composition of the hydro-distilled essential oil (HD-EO), obtained from the fresh aerial parts (inflorescence heads (Inf), leaves (L), and stems (St)) of Conyza canadensis growing wild in Jordan was determined by GC/MS. Additionally, the methanolic extract obtained from the whole aerial parts of C. canadensis (CCM) was examined for its total phenolic content (TPC), total flavonoids content (TFC), DPPH radical scavenging activity, iron chelating activity and was then analyzed with LC-MS/MS for the presence of certain selected phenolic compounds and flavonoids. The GC/MS analysis of CCHD-EOs obtained from the different aerial parts revealed the presence of (2E, 8Z)-matricaria ester as the main component, amounting to 15.4% (Inf), 60.7% (L), and 31.6% (St) of the total content. Oxygenated monoterpenes were the main class of volatile compounds detected in the Inf-CCHD-EO. However, oils obtained from the leaves and stems were rich in polyacetylene derivatives. The evaluation of the CCM extract showed a richness in phenolic content (95.59 ± 0.40 mg GAE/g extract), flavonoids contents (467.0 ± 10.5 mg QE/ g extract), moderate DPPH radical scavenging power (IC50 of 23.75 ± 0.86 µg/mL) and low iron chelating activity (IC50 = 5396.07 ± 15.05 µg/mL). The LC-MS/MS profiling of the CCM extract allowed for the detection of twenty-five phenolic compounds and flavonoids. Results revealed that the CCM extract contained high concentration levels of rosmarinic acid (1441.1 mg/kg plant), in addition to caffeic acid phenethyl ester (231.8 mg/kg plant). An antimicrobial activity assessment of the CCM extract against a set of Gram-positive and Gram-negative bacteria, in addition to two other fungal species including Candida and Cryptococcus, showed significant antibacterial activity of the extract against S. aureus with MIC value of 3.125 µg/mL. The current study is the first phytochemical screening for the essential oil and methanolic extract composition of C. canadensis growing in Jordan, its antioxidant and antimicrobial activity.

Chemical Composition, In Vitro Antitumor Effect, and Toxicity in Zebrafish of the Essential Oil from Conyza bonariensis (L.) Cronquist (Asteraceae).

The essential oil from Conyza bonariensis (Asteraceae) aerial parts (CBEO) was extracted by hydrodistillation in a Clevenger-type apparatus and was characterized by gas chromatography-mass spectrometry. The antitumor potential was evaluated against human tumor cell lines (melanoma, cervical, colorectal, and leukemias), as well as non-tumor keratinocyte lines using the MTT assay. The effect of CBEO on the production of Reactive Oxygen Species (ROS) was evaluated by DCFH-DA assay, and a protection assay using the antioxidant N-acetyl-L-cysteine (NAC) was also performed. Moreover, the CBEO toxicity in the zebrafish model was assessed. The majority of the CBEO compound was (Z)-2-lachnophyllum ester (57.24%). The CBEO exhibited selectivity towards SK-MEL-28 melanoma cells (half maximal inhibitory concentration, IC50 = 18.65 ± 1.16 µg/mL), and induced a significant increase in ROS production. In addition, the CBEO's cytotoxicity against SK-MEL-28 cells was reduced after pretreatment with NAC. Furthermore, after 96 h of exposure, 1.5 µg/mL CBEO induced death of all zebrafish embryos. Non-lethal effects were observed after exposure to 0.50-1.25 µg/mL CBEO. Additionally, significant alterations in the activity of enzymes associated with oxidative stress in zebrafish larvae were observed. These results provide evidence that CBEO has a significant in vitro antimelanoma effect by increasing ROS production and moderate embryotoxicity in zebrafish.

Molecular Mechanisms Responsible for In Vitro Cytotoxic Attributes of Conyza bonariensis Extract against Lymphoblastic Leukaemia Jurkat Cells.

BACKGROUND: Conyza bonariensis is known to have anti-cancer properties. OBJECTIVE: The current study investigated the in vitro pro-apoptotic properties of Conyza bonariensis (C. bonariensis) towards human lymphoblastic leukemia Jurkat cells. METHODS: Ariel parts of C. bonariensis were macerated in a non-polar (n-Hexane) solvent. MTS cell viability assay was employed to determine the cytotoxic activity of the extract towards human leukemia Jurket cells and normal Peripheral Blood Mononuclear Cells (PBMCs). The phytochemical composition of the extract was screened using HPLC method. Flow cytometric studies (FACS) were conducted to explore the pro-apoptotic potential of the extract. Western blot studies were employed to identify the molecular targets involved in the induction of apoptosis. RESULTS: The n-hexane extract showed selective cytotoxic activity towards Jurkat cells. FACS analysis indicated that the extract induced early and late apoptosis in Jurkat cells. Western blot studies revealed that the extract downregulated the expression of DNMT1, SIRT1, and UHRF1 with a simultaneous up-regulation of p73 and caspases-3 proteins expression. HPLC characterization of the extract revealed the presence of phenolic compounds. CONCLUSION: Overall, these findings demonstrate that the anti-cancer effects of a Conyza bonariensis extract towards human lymphoblastic leukemia Jurkat cells are due to the modulation of the activity of multiple oncogenic and tumor suppressor proteins. Phenolic contents of the extract are proposed to be responsible for these activities.

Pharmacological, Phytochemical and histopathological basis of Conyza bonariensis in the potential management of diabetes mellitus.

To evaluate the anti-diabetic potential of aqueous methanolic extract of Conyza bonariensis amongst the Wistar rats. Phytochemical and High Performance Liquid Chromatography (HPLC) analyses of phenols and flavonoids were examined. The plant extract (250 and 500mg/kg/day) was explored for its anti-hyperglycemic effect for 14 days in normoglycemic and alloxan-induced diabetic rats using the oral glucose tolerance test (OGTT). HPLC analyses demonstrated the composition of the plant extract as gallic acid, cinnamic acid, quercetin, p-coumaric acid and syringic acid. The blood glucose concentrations in experimental diabetic as well as non-diabetic rats significantly decreased with doses 250 and 500 mg/kg in OGTT. Moreover, the significant drop in fasting glucose level was observed following 14 days of therapy. It also ameliorated the serum cholesterol, total protein, low and high density lipoproteins, glycosylated hemoglobin A1C and serum amylase with respect to untreated rats suffering from diabetes. There appeared to be no significant alteration with regard to body weight amongst the treated rats. The plant extract revamped the pancreatic islets of Langerhans and abridged alloxan-induced degenerative changes in the liver. It can be concluded that Conyza bonariensis extract has a pronounced hypoglycemic effect on diabetes due to the presence of phytochemicals.

Neo-clerodane diterpenoids from Conyza pyrrhopappa Sch.Bip. ex A.Rich.

Two hitherto unknown neo-clerodane-type diterpenoids along with twelve known compounds have been isolated from Conyza pyrrhopappa Sch.Bip. ex A.Rich, a medicinal plant traditionally used across tropical Africa to relieve fever. The structures of isolates have been elucidated by a combination of spectroscopic techniques. The crude extract and the isolated compounds were evaluated in the Hela-S3 cell line and in a panel of microorganisms (bacteria and fungi) at concentrations up to 50 µg/mL. The new compounds were inactive while the pentamethylated flavonoids showed low to significant activity against the cancer cell line used. However, none of the samples showed any activity against the tested microorganisms at this concentration. The present manuscript is the first investigation of the cytotoxicity of phytochemicals and extract from C. pyrrhopappa.

Purification and Biochemical Characterization of a New Protease Inhibitor from Conyza dioscoridis with Antimicrobial, Antifungal and Cytotoxic Effects.

The main objective of the current study was the extraction, purification, and biochemical characterization of a protein protease inhibitor from Conyzadioscoridis. Antimicrobial potential and cytotoxic effects were also examined. The protease inhibitor was extracted in 0.1 M phosphate buffer (pH 6-7). Then, the protease inhibitor, named PDInhibitor, was purified using ammonium sulfate precipitation followed by filtration through a Sephadex G-50 column and had an apparent molecular weight of 25 kDa. The N-terminal sequence of PDInhibitor showed a high level of identity with those of the Kunitz family. PDInhibitor was found to be active at pH values ranging from 5.0 to 11.0, with maximal activity at pH 9.0. It was also fully active at 50 °C and maintained 90% of its stability at over 55 °C. The thermostability of the PDInhibitor was clearly enhanced by CaCl2 and sorbitol, whereas the presence of Ca2+ and Zn2+ ions, Sodium taurodeoxycholate (NaTDC), Sodium dodecyl sulfate (SDS), Dithiothreitol (DTT), and ß-ME dramatically improved the inhibitory activity. A remarkable affinity of the protease inhibitor with available important therapeutic proteases (elastase and trypsin) was observed. PDInhibitor also acted as a potent inhibitor of commercial proteases from Aspergillus oryzae and of Proteinase K. The inhibitor displayed potent antimicrobial activity against gram+ and gram- bacteria and against fungal strains. Interestingly, PDInhibitor affected several human cancer cell lines, namely HCT-116, MDA-MB-231, and Lovo. Thus, it can be considered a potentially powerful therapeutic agent.

Essential Oil Compositions of Three Invasive Conyza Species Collected in Vietnam and Their Larvicidal Activities against Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus.

Mosquito-borne infectious diseases are a persistent problem in tropical regions of the world, including Southeast Asia. Vector control has relied principally on synthetic insecticides, but these have detrimental environmental effects and there is an increasing demand for plant-based agents to control insect pests. Invasive weedy plant species may be able to serve as readily available sources of essential oils, some of which may be useful as larvicidal agents for control of mosquito populations. We hypothesize that members of the genus Conyza (Asteraceae) may produce essential oils that may have mosquito larvicidal properties. The essential oils from the aerial parts of Conyza bonariensis, C. canadensis, and C. sumatrensis were obtained by hydrodistillation, analyzed by gas chromatography-mass spectrometry, and screened for mosquito larvicidal activity against Aedes aegypti, Ae. albopictus and Culex quinquefasciatus. The essential oils of C. canadensis and C. sumatrensis, both rich in limonene (41.5% and 25.5%, respectively), showed notable larvicidal activities against Ae. aegypti (24-h LC50 = 9.80 and 21.7 µg/mL, respectively) and Ae. albopictus (24-h LC50 = 18.0 and 19.1 µg/mL, respectively). These two Conyza species may, therefore, serve as sources for alternative, environmentally-benign larvicidal control agents.

Spiroconyone A, a new phytosterol with a spiro [5,6] ring system from Conyza japonica.

Spiroconyone A (1), the first rearranged phytosterol featuring an unusual spiro [5,6] ring system, and nine known compounds (2-10) were isolated from the aerial parts of Conyza japonica. The structure of 1 was elucidated through spectroscopic methods, and its absolute configuration was determined by single-crystal X-ray diffraction analysis. Enzyme-based assay revealed that spiroconyone A showed weak TDP1 inhibition and compounds 7 and 10 showed TDP1 inhibition with IC50 values of 36 µM and 16 µM, respectively. MTT assay indicated that 7 and 10 showed a strong synergistic effect with the clinical TOP1 inhibitor topotecan in MCF-7 cells. Compound 5 displayed the most potent cytotoxicity against MCF-7 cells with a GI50 value of 3.3 µM. Furthermore, a hypothetical biosynthetic pathway for 1 was proposed. This work provides valuable information that the secondary metabolites from Conyza japonica could be developed as anticancer agents.

Sesquiterpenoids from the aerial parts of Conyza japonica and their inhibitory activity against nitric oxide production.

Four new sesquiterpenoids, conyterpenols A - D (1-4), along with nineteen known analogues (5-23) were isolated from the aerial parts of Conyza japonica. The structures of 1-4 were determined through spectroscopic analysis, while their absolute configurations were determined by comparison of calculated and experimental electronic circular dichroism (ECD) spectra. Conyterpenol D (4) was a new type of sesquiterpenoid with a seven-membered lactone ring. Compounds 1-23 were evaluated for their inhibitory activity against LPS-induced nitric oxide production in RAW264.7 macrophages and cytotoxicity against human hepatoma cell line (HepG2) and human breast adenocarcinoma cell line (MCF-7). Compounds 3, 4, and 12 displayed moderate inhibition against NO production with IC50 values in the range of 26.4-33.6 µM. And all compounds showed no obvious cytotoxicity against these two cancer cell lines at 100 µM.

Flaxleaf Fleabane Leaves (Conyza bonariensis), A New Functional Nonconventional Edible Plant?

This work aimed to investigate the phytochemical composition, nutritional value, antioxidant, antihemolytic, antihyperglycemic, and antiproliferative activities of flaxleaf fleabane (Conyza bonariensis) leaves. Different concentrations of water and ethanol (0:100, 25:75, 50:50, 75:25, and 100:0 v/v) were used in the extraction process and results showed that the hydroalcoholic extract (50:50 v/v) presented the highest total phenolics, ortho-diphenolics, Folin-Ciocalteu reducing capacity, FRAP, and Fe2+ chelating ability values. Flaxleaf fleabane leaves (FFL) contained 19.6 g/100 g of fibers and 26 g/100 g of proteins. Ellagic acid, procyanidin A2, caffeic, rosmarinic, gallic, and 2,5-dihydroxybenzoic acids were the main phenolics. This phenolic-rich extract inhibited the lipid oxidation of Wistar rat brain (IC50 = 863.0 mg GAE/L), inhibited α-glucosidase activity (IC50 = 435.4 µg/mL), protected human erythrocytes against mechanical hemolysis at different osmolarity conditions, and showed cytotoxic/antiproliferative effects against human ileocecal adenocarcinoma cells (HCT8; IC50 = 552.6 µg/mL) but no cytotoxicity toward noncancerous human lung fibroblast (IMR90). Overall, FFL showed potential to be explored by food companies to be a source of proteins, natural color substances, and phenolic compounds. PRACTICAL APPLICATION: Flaxleaf fleabane leaves (FFL) are usually burnt or partially given to cattle, without a proper utilization as a source of nutrients for human nutrition. Here, we studied the nutritional composition, phenolic composition, and toxicological aspects of FFL using different biological protocols. FFL was proven to be a rich source of proteins and dietary fibers and showed antioxidant activity measured by chemical and in vitro biological assays. Additionally, as it did protected human red cells and did not show cytotoxicity, we assume FFL has relative safety to be consumed as a nonconventional edible plant.

Phytosynthesis of nearly monodisperse CuO nanospheres using Phyllanthus reticulatus/Conyza bonariensis and its antioxidant/antibacterial assays.

In the present article we have developed an eco-friendly, phytosynthetic, cost-effective and straightforward method for the synthesis of nearly monodisperse CuO nanospheres (NSP) using leaf extracts of medicinal plants Phyllanthus reticulatus (PR) and Conyza bonariensis (CB) as novel green reducing agents. Copper nitrate (Cu (NO3)2) was used as a precursor. The stoichiometric ratio of both leaf extracts (PR/CB) and Cu(NO3)2 was standardized for the synthesis of NSP. During formation of CuO NSP, a color of solution gradually changed from light greenish-blue to black with a number of intermediate stages and it correlated to the reduction reaction catalyzed by phytochemicals. As-synthesized materials were characterized in detail at the structural, electronic level and morphological authentication by XRD, FT-IR, EDS, UV-DRS, Raman, XPS, SEM, TEM, BET and AFM. SEM studies of phytosynthesized materials revealed nearly monodisperse nanospheres, while TEM rendered average particles size 4-14 nm. Also, AFM profiles suggested a homogenized nature of the nanospheres. Then, the antioxidant property was obtained by α, α-diphenyl-ß-picrylhydrazyl (DPPH). Ethanolic, methanolic extracts were used for the antioxidant activity, while ascorbic acid was used as a standard medium. Each plant extract exhibited noteworthy antioxidant activity. Moreover, the antibacterial activity of CuO NSP (PR/CB) was tested against human pathogenic bacteria viz. gram-positive Staphylococcus aureus, Klebsiella pneumoniae, and gram-negative Escherichia coli. Result rendered effective antibacterial activity against Escherichia coli.

Synthesis and characterization of phytochemical fabricated zinc oxide nanoparticles with enhanced antibacterial and catalytic applications.

A "green route" to fabricate nanoparticles has emerged as a revolutionary approach. The reported work presents a green approach to synthesize ZnO nanoparticles using Conyza canadensis plant leaves extract. The synthesis of ZnO was conducted at two different temperatures i.e. 30 °C and 80 °C. ZnO nanoparticles prepared at 80 °C were smaller in size and exhibited spherical morphology. The prepared nanomaterials were examined for the reduction of organic dyes i.e. methylene blue and methyl orange. The fabricated ZnO nanoparticles synthesized at 80 °C were found to be highly active for the reduction of aforementioned dyes with 94.5% reduction of MO and 85.3% reduction of MB in 45 min and 20 min respectively. The rate constant (k) for this reduction of MO was found to be 5.781 × 10-3 s-1 in the absence of a catalyst and 5.843 × 10-2 s-1 in the presence of ZnO NPs catalyst. The rate constant (k) for the reduction of MB was found to be 4.7 × 10-3 s-1 in the absence of a catalyst and 9.936 × 10-3 s-1 in the presence of ZnO NPs catalyst. ZnO nanoparticles synthesized at 80 °C were examined for their antibacterial activity. The biogenic ZnO nanoparticles exhibited strong antibacterial activity against E. coli and S. aureus with a zone of inhibition (16 mm) and (14 mm) respectively. This high antibacterial and catalytic activity of biogenic ZnO nanoparticles can be attributed to its small size, good dispersion, and well-defined morphology.

Antibacterial activities of the phytochemicals-characterized extracts of Callistemon viminalis, Eucalyptus camaldulensis and Conyza dioscoridis against the growth of some phytopathogenic bacteria.

Three bacterial isolates were isolated from infected potato tubers showing soft and brown rots like symptoms as well as one isolate from infected peach tree showing crown gall symptom. The morphological, biochemical and molecular assays proved that bacterial isolates belonging to Pectobacterium carotovorum subsp. carotovorum, Ralstonia solanacearum, Dickeya spp. and Agrobacterium tumefaciens. The acetone (AcE) and n-butanol (ButE) extracts of Callistemon viminalis flowers and essential oil from aerial parts of Conyza dioscoridis as well as ButE of Eucalyptus camaldulensis bark are evaluated at different concentrations against the growth of the isolated bacteria. The diameter of inhibition zone (IZ) and the minimum inhibitory concentrations (MICs) are compared. Results indicated that the highest IZ values were 20.0 mm and 18.3 mm for E. camaldulensis bark ButE and C. viminalis flower ButE, respectively, against P. carotovorum; 16.3 mm and 16.0 mm for E. camaldulensis bark ButE and C. viminalis flower ButE, respectively, against R. solanacearum; 18.5 mm for C. viminalis flower AcE and C. dioscoridis aerial parts EO against Dickeya spp.; and 15.0 mm for C. viminalis flower AcE against A. tumefaciens. MICs ranged from <16 µg/mL for D. solani to >4000 µg/mL for A. tumefaciens. It was proved that C. viminalis flowers AcE contains mainly 5-hydroxymethylfurfural (20.6%), palmitic acid (18.5%), and pyrogallol (16.4%); while C. viminalis flower ButE contains palmitic acid (36.3%), 2-hydroxymyristic acid (9.4%), 5-hydroxymethylfurfural (7.2%), and shikimic acid (6.6%); whereas E. camaldulensis bark ButE contains 8-nonynoic acid methyl ester (45.6), camphor (30.9%), menthol (8.8%), and 1,8-cineole (eucalyptol) (8.2%), whilst the EO of C. dioscoridis aerial parts comprises Z-(13,14-epoxy)tetradec-11-en-1-ol acetate (11.6%), γ-elemene (10.2%), tau.-muurolol (7.1%), and cadina-3,9-diene (4.7%). It can be concluded that phytochemical extracts of C. viminalis, E. camaldulensis and C. dioscoridis demonstrated strong to moderate antibacterial effects against the studied plant bacterial pathogens.

Essential oils of aromatic Egyptian plants repel nymphs of the tick Ixodes ricinus (Acari: Ixodidae).

Due to the role of Ixodes ricinus (L.) (Acari: Ixodidae) in the transmission of many serious pathogens, personal protection against bites of this tick is essential. In the present study the essential oils from 11 aromatic Egyptian plants were isolated and their repellent activity against I. ricinus nymphs was evaluated Three oils (i.e. Conyza dioscoridis L., Artemisia herba-alba Asso and Calendula officinalis L.) elicited high repellent activity in vitro of 94, 84.2 and 82%, respectively. The most active essential oil (C. dioscoridis) was applied in the field at a concentration of 6.5 µg/cm2 and elicited a significant repellent activity against I. ricinus nymphs by 61.1%. The most repellent plants C. dioscoridis, C. officinalis and A. herba-alba yielded essential oils by 0.17, 0.11 and 0.14%, respectively. These oils were further investigated using gas chromatography-mass spectrometry analysis. α-Cadinol (10.7%) and hexadecanoic acid (10.5%) were the major components of C. dioscoridis whereas in C. officinalis, α-cadinol (21.2%) and carvone (18.2%) were major components. Artemisia herba-alba contained piperitone (26.5%), ethyl cinnamate (9.5%), camphor (7.7%) and hexadecanoic acid (6.9%). Essential oils of these three plants have a potential to be used for personal protection against tick bites.

Saponin fraction isolated from Conyza blinii H.Lév. demonstrates strong anti-cancer activity that is due to its NF-κB inhibition.

CBS (Conyza blinii saponin) is the total triterpenoidal saponins of Conyza blinii H.Lév which is a type of traditional Chinese medicine (TCM). We have discovered that CBS has a profound cytostatic activity against a range of solid tumour cells in a time- and dose-dependent manner. We also confirm that the cytostatic activity of CBS originates from its apoptosis induction effect. Additionally, we use immunoblot to find out that the apoptosis induction effect of CBS is attributable to the activation of mitochondrial pathway. Mechanistic study demonstrates that CBS is an effective NF-κB inhibitor. It inhibits p65 nuclear translocation and NF-κB downstream gene expression, including XIAP, survivin, Bcl-xL, COX-2, cyclin D1, MMP-2, MMP-9 in HeLa cells. Tumour xenografted animal models verify the anti-cancer efficacy in vivo. Tumour growth is significantly repressed in two CBS-treated groups compared with the controls (P < 0.001). CBS treatment (i.g.) leads to a 48.5% and 57.0% reduction in terms of tumour weight for the 10 and 20 mg/kg dosed groups respectively. Also no apparent observable adverse effects can be seen. These results suggest that CBS obliterate tumour, at least in part due to its NF-κB inhibition, which creates potential for CBS to be developed as a practical cancer treatment.

In vitro screening of Cymbopogon jwarancusa and Conyza canadensis against liver flukes.

Aim of present study was to screen medicinal plants for flukicidal activity in vitro to develop alternative sources of treatment for trematodes infection. For this purpose, crude methanolic extracts (CME) of Cymbopogn jwarancusa and Conyza canadensis were prepared and live adult flukes viz; Fasciola gigantica, and Paramphistomum cervi isolated from liver and bile ducts of slaughtered buffalo were subjected to different drug concentrations as well as positive and negative control. Motility inhibition and paralysis leading to the death of parasites was considered as flukicidal activity of plants extracts. The results revealed that CME of C. jwarancusa and C. canadensis showed significant (P<0.05) flukicidal activity compared to positive control. Also there was a significant effect of different concentrations (P<0.05) and exposure of time on the flukes (P<0.05). Furthermore, ED50 for C. jwarancusa and C. canadensis against F. gigantica were 13.1 and 41.4 mg/ml, respectively. In the case of P. cervi, it was 10.8 and 29.0 mg/ml. It can be concluded that both tested plants showed greater flukicidal activity as compared to positive control with Albendazole till the 8(th) hr. These potent plants needs further studies invivo to elucidate their mode of action.

Isotopic Differences between Forage Consumed by a Large Herbivore in Open, Closed, and Coastal Habitats: New Evidence from a Boreal Study System.

Documenting habitat-related patterns in foraging behaviour at the individual level and over large temporal scales remains challenging for large herbivores. Stable isotope analysis could represent a valuable tool to quantify habitat-related foraging behaviour at the scale of individuals and over large temporal scales in forest dwelling large herbivores living in coastal environments, because the carbon (δ13C) or nitrogen (δ15N) isotopic signatures of forage can differ between open and closed habitats or between terrestrial and littoral forage, respectively. Here, we examined if we could detect isotopic differences between the different assemblages of forage taxa consumed by white-tailed deer that can be found in open, closed, supralittoral, and littoral habitats. We showed that δ13C of assemblages of forage taxa were 3.0 ‰ lower in closed than in open habitats, while δ15N were 2.0 ‰ and 7.4 ‰ higher in supralittoral and littoral habitats, respectively, than in terrestrial habitats. Stable isotope analysis may represent an additional technique for ecologists interested in quantifiying the consumption of terrestrial vs. marine autotrophs. Yet, given the relative isotopic proximity and the overlap between forage from open, closed, and supralittoral habitats, the next step would be to determine the potential to estimate their contribution to herbivore diet.

Antinociceptive and hypoglycaemic evaluation of Conyza filaginoides (D.C.) Hieron Asteraceae.

OBJECTIVES: This work was undertaken to assess the antinociceptive and hypoglycaemic properties of a quantified extract of Conyza filaginoides (CFOE), as well as the antinociceptive potential of rutin, the main active compound of the plant, in normoglycaemic and/or hyperglycaemic mice (nicotinamide-streptozotocin, NA-STZ). METHODS: The antinociceptive effect of CFOE was evaluated using the writhing, hotplate and formalin tests in mice. Rutin was also examined with the formalin test. In addition, the antihyperalgesic effect of CFOE was evaluated in hyperglycaemic mice. The hypoglycaemic effect of CFOE was tested using an acute hypoglycaemic assay, and oral glucose and sucrose tests in normoglycaemic and hyperglycaemic mice. KEY FINDINGS: CFOE showed antinociceptive effect when tested in normoglycaemic mice in the writhing and hotplate tests (31.6-316 mg/kg). CFOE was also active in both normoglycaemic and hyperglycaemic mice in the formalin test (10-100 µg/paw) revealing its antihyperalgesic property. Rutin reduced the nociceptive behaviour in the formalin test; its mechanism of action seems to involve GABAergic and opioid pathways. CFOE possessed noted hypoglycaemic and antihyperglycaemic effects in normoglycaemic and hyperglycaemic mice (31.6-316 mg/kg). CONCLUSIONS: The antinociceptive, antihyperalgesic and hypoglycaemic effects of C. filaginoides found in this study support the contemporary uses of the plant in Mexican folk medicine.

Antioxidant and antibacterial activities of extracts from Conyza bonariensis growing in Yemen.

This study aims to examine the antioxidant and antibacterial activities and phenolic contents of Conyza bonariensis growing in Yemen. The whole plants of C. bonariensis were ultrasonically extracted by ethanol. The antioxidant activity of the extract was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ß-carotene bleaching (BCB). The effectiveness of the extract on the growth inhibition of some indicators of foodborne illness bacteria were investigated by agar well diffusion assay. The total phenols (TP), total flavonoids (TF), total tannins (TT), and total anthocyanins (TA) were determined by Folin-Ciocalteu method, aluminium chloride method, Folin and Ciocalteu method, and pH-differential method, respectively. The extract of C. bonariensis possessed TP 144.1 mg/g, TF 143 mg/g, TT 0.99mg/g, and TA 0.97mg 100g, with 94.57% inhibition of DPPH and 92.47% inhibition of BCB, and strong inhibitory effects against tested bacteria, which was approximate to those of peel extract of Punica granatum.

Bioactivity-guided isolation of antiplasmodial constituents from Conyza sumatrensis (Retz.) E.H. Walker.

Conyza sumatrensis (Retz.) E.H. Walker (Cs) leaves are used for traditional treatment of malaria in Cameroon. However, the antimalarial activity of the leaf constituents of this plant is still unexplored. The aim of our investigation was to evaluate the antiplasmodial activity of some bioactive constituents from Cs leaves. Compounds were isolated from Cs leaves and structurally elucidated using extensive spectroscopic analysis. The in vitro antiplasmodial activity of the extracts and pure compounds were evaluated on chloroquine-sensitive strain (NF54) of Plasmodium falciparum. The in vivo assay was done by administering seven doses of extracts in mice infected with Plasmodium berghei K173 through oral route. Cytotoxicity of pure compounds on murine macrophage cells was performed through [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] (MTT) test. Hemolysis and lactate dehydrogenase assays were also carried out using standard procedures. The in silico prediction of bioactive constituents was performed through Autodock Vina. Polarity-based extracts from Cs were found to be active against P. falciparum (NF54) and P. berghei (K173) in vitro and in vivo respectively. Further, bioactivity-guided isolation of n-hexane fraction yielded three compounds, (1), (2) and (3) with IC50 of 34, 17.9 and 18µg/ml, respectively, while the ethyl acetate fraction afforded the fourth compound with an IC50 of 25µg/ml, indicating anti-malarial potential of Cs through PfLDH interaction without compromising normal cell growth. This study reports for the first time, the antiplasmodial activity of bioactive constituents from Cs and confirms its traditional use.