The preventive effects of Centaurea maroccana Ball. extract against oxidative stress induced by cisplatin in mice brains: in vitro and in vivo studies.

Since antiquity, Centaurea species have been used in folk medicine to treat several diseases owing to their potential biological activities that distinguish this genus such as antioxidant, anticancer, and anti-inflammatory effect. The current study aimed to investigate the possible neuroprotective effects of the n-butanol extract of Centaurea maroccana (BECM) against cisplatin (CP) induced neurotoxicity in mice. BECM's potential neuroprotective properties were studied in vitro and in vivo models. Male Swiss albino mice were orally received BECM (200 mg/kg) for 10 days before a single intraperitoneal injection of cisplatin (8 mg/kg). Vitamin E (100 mg/kg) was given daily by gavage as a positive control. In vitro results revealed that BECM inhibited lipid peroxidation (LPO) levels and acetylcholinesterase (AChE) activity. In vivo findings showed that BECM pretreatment was able to regulate lactate dehydrogenase (LDH) levels and to improve CP-induced cholinergic dysfunction by inhibiting AChE activity in mice brains. Moreover, BECM attenuated CP-provoked oxidative stress by suppressing LPO levels, increasing total antioxidant capacity (TAC) and enhancing the activities of antioxidant enzymes (catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx) and glutathione S-transferase (GST)) in both brain cytosolic and mitochondrial fractions. The histological analysis exhibited neurotoprotective effect of BECM by protecting the cerebral cortex and reducing the histomorphological alterations resulted by cisplatin. Interestingly, our extract achieved neuroprotection comparable to vitamin E in most evaluated parameters. It appears that protective potency of BECM against CP-induced neurotoxicity could be related to its richness in polyphenols confirmed by liquid-chromatography tandem mass spectrometry analysis (LC-MS/MS).

Halimium halimifolium: From the Chemical and Functional Characterization to a Nutraceutical Ingredient Design.

Halimium halimifolium (Hh) is a shrub used in Algerian folk medicine to treat gastrointestinal pain. An UHPLC-PDA-ESI/MSn method was developed to identify the metabolic profile of the traditionally used infusion (Hh-A) from the aerial parts. The structures of flavanols were confirmed by NMR analysis after the isolation procedure from a hydrohalcolic extract (Hh-B) that also allowed for the identification of phenolic acids, an aryl butanol glucoside, and different derivatives of quercetin, myricetin, and kaempferol. Tiliroside isomers were the chemical markers of Hh-A and Hh-B (54.33 and 36.00 mg/g, respectively). Hh-A showed a significant scavenging activity both against the radicals 1,1-diphenyl-2-picrylhydrazyl and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (EC50 = 10.49 µg/mL and TEAC value = 1.98 mM Trolox/mg infusion) and the lipopolysaccharide-induced reactive oxygen species release in A375 and HeLa cells. Moreover, the antihyperglycemic properties, by inhibiting the α-amylase and α-glucosidase enzymes (IC50 = 0.82 mg/mL and 25.01 µg/mL, respectively), were demonstrated. To upgrade the therapeutic effect, a microencapsulation process is proposed as a strategy to optimize stability, handling, and delivery of bioactive components, avoiding the degradation and loss of the biological efficacy after oral intake. Hh-loaded microparticles were designed using cellulose acetate phthalate as the enteric coating material and spray drying as a production process. The results showed a satisfactory process yield (67.9%), encapsulation efficiency (96.7%), and micrometric characteristics of microparticles (laser-scattering, fluorescent, and scanning electron microscopy). In vitro dissolution studies (USPII-pH change method) showed that Hh-loaded microparticles are able to prevent the release and degradation of the bioactive components in the gastric tract, releasing them into the intestinal environment.

In vitro antioxidant, DNA-damaged protection and antiproliferative activities of ethyl acetate and n-butanol extracts of Centaurea sphaerocephalaL.

This study aimed to evaluate the in vitro antiproliferative and inhibition of oxidative DNA-damage activities of n-butanol (n-BuOH) extract of Centaurea sphaerocephala. The in vitro antioxidant activity of the ethyl acetate (EtOAc) and the n-BuOH extracts of this plant were also assayed. To investigate the antioxidant potential, extracts were tested for their capacity to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH·) and to inhibit lipid peroxidation using the TBARs method. The contents of total phenolics and flavonoids were measured. Additionally, antiproliferative activity and DNA-damage inhibition of the n-BuOH extract was determined using XCELLigence RTCA instrument and photolyzing 46966 plasmid, respectively. The results exhibited that the scavenging abilities of the EtOAc extract were better than the n-BuOH extract with an IC50= 11.59 µg/mL and 16.67 µg/mL for both extracts, respectively. The phenolic and flavonoid contents were found higher in the n-BuOH and EtOAc extracts. Furthermore, our results showed that n-BuOH extract exhibited a remarkable inhibition of lipid peroxidation with an IC50 of 340.94±7.49 µg/mL and had an antiproliferative effect against Hela cells. Extracts of C. sphaerocephala showed antioxidant activity on scavenging DPPH·. In addition, the n-BuOH extract inhibited the lipid peroxidation and exhibited an antiproliferative effect against HeLa cells line (human cervix carcinoma).

Qualitative and Quantitative Phytochemical Analysis of Different Extracts from Thymus algeriensis Aerial Parts.

This study was performed to evaluate the metabolite recovery from different extraction methods applied to Thymusalgeriensis aerial parts. A high-performance liquid chromatographic method using photodiode array detector with gradient elution has been developed and validated for the simultaneous estimation of different phenolic compounds in the extracts and in their corresponding purified fractions. The experimental results show that microwave-assisted aqueous extraction for 15 min at 100 °C gave the most phenolics-enriched extract, reducing extraction time without degradation effects on bioactives. Sixteen compounds were identified in this extract, 11 phenolic compounds and five flavonoids, all known for their biological activities. Color analysis and determination of chlorophylls and carotenoids implemented the knowledge of the chemical profile of this plant.

Atriplex mollis Desf. Aerial Parts: Extraction Procedures, Secondary Metabolites and Color Analysis.

A method using high-performance liquid chromatography coupled with a photodiode array detector was proposed for the rapid characterization of different phenolic constituents from the extracts of Atriplex mollis aerial parts. Atriplex species are known for their multiple biological activities, but no information is available in the literature about A. mollis. With the aim to firstly characterize the main secondary metabolites of this plant, so as to orient better the biological evaluation, we applied three different extraction procedures and compared the chromatographic results. Microwave-assisted extraction gave the best yield and recovery of important compounds such as gallic acid, catechin, chlorogenic acid, p-OH benzoic acid, rutin, sinapinic acid, t-ferulic acid, naringenin and benzoic acid. These constituents belong to three important chemical classes: phenolic acids, flavonoids and monoterpenes. Color evaluation and analysis of chlorophylls (a and b) and carotenoids complete the preliminary profile of this plant. From these analyses, Atriplex mollis is a source of bioactive compounds (especially rutin, t-ferulic acid and gallic acid) and could be recommended as a plant of phyto-pharmaceutical relevance, opening new perspectives on this salt-tolerant plant.

Exploring the Bioactive Terpenoid Content of an Algerian Plant of the Genus Pulicaria: The ent-Series of Asteriscunolides.

Chemical analysis of the chloroform extract of the aerial parts of the Algerian plant Pulicaria undulata exhibiting anti-inflammatory activity resulted in the isolation of 10 new humulene sesquiterpenoids, 1-10, belonging to the asteriscunolide family of compounds. The structure and relative configuration have been defined by NMR data, whereas the absolute configuration has been established by ECD analysis. Compounds 1-10 include enantiomers of the known asteriscunolides A-D and tetrahydroasteriscunolide previously reported from the genera Asteriscus and Nauplius. Compounds 1 and 10 showed in vitro anti-inflammatory activity by inhibiting heat-induced albumin denaturation with IC50 values of 23.76 and 220.42 µM.

On-Line Screening, Isolation and Identification of Antioxidant Compounds of Helianthemum ruficomum.

Many Helianthemum species (Cistaceae) are recognized for their various medicinal virtues. Helianthemum ruficomum is an endemic species to the septentrional Sahara on which no report is available so far. The purpose of this work was to investigate the chemical composition and the radical scavenging capacity of this species and its isolated components. Collected from Mougheul (south-west of Algeria), the aerial parts were macerated with 80% EtOH/H2O, after evaporation, the remaining extract was diluted with H2O and extracted with petroleum ether, chloroform, ethyl acetate and n-butanol. EtOAc and n-BuOH extracts were evaluated for their free radical scavenging capacity by on-line HPLC-ABTS•+ assay. The obtained data which were confirmed by TEAC and ORAC assays, allowed guiding the fractionation of these extracts by CC, TLC and reverse phase HPLC. Among the components, 14 were isolated and identified by spectroscopic analyses: protocatechuic acid (1), trans-tiliroside (2), cis-tiliroside (3), astragalin (4), picein (7), vanillic acid 4-O-ß-d-glucopyranoside (8), lavandoside (9), 4-hydroxybenzoic acid 4-O-ß-d-glucopyranoside (10), nicotiflorin (11), rutin (12), vicenin-2 (13), narcissin (14) and stigmasterol (5) and ß-sitosterol (6) as a mixture (71% and 29%, respectively). Compounds 5, 7, 8, 9, 10 and 14 were new for the genus Helianthemum. The antioxidant power of all the isolated compounds was also evaluated by HPLC-ABTS•+, TEAC and ORAC assays. The results clearly indicated high antioxidant potential of the extracts and tested compounds of this species especially, compounds 1, 4, 8, 9, 10 and 12.

Cynara Cardunculus Flavonoids-rich Fraction Alleviates Liver Injury in Mice Overconsumed Fructose Model.

BACKGROUND: Non-alcoholic Fatty liver disease (NAFLD) is becoming a major global health burden in the world. Cynara cardunculus is an edible plant growing wild in the North of Algeria. Its potential as a source of health-promoting compounds is still underexplored. OBJECTIVES: This study aimed to explore the preventive effect of Cynara cardunculus (C. cardunculus) on the NAFLD model. METHODS: Total flavonoid contents (TFC) and in vitro antioxidant effects of butanolic (n- BuTOH) and ethyl acetate (EtOAc) fractions on scavenging the ABTS+ radical, inhibition of lipid peroxidation and reducing power proprieties were assessed. The n-ButOH fraction showed the highest TFC and antioxidant capacity in all realized assays. This fraction is used for anti- NAFLD experiments. Adult male Albinos mice were divided into four groups. Group 1 was normal control. Group 2 was watered with 30% of fructose for three weeks to induce the NAFLD model. Group 3 and Group 4 were co-treated with C. cardunculus n-ButOH fractions and Atorvastatin, respectively for three weeks. Blood and livers were collected for biochemical and histological analysis. RESULTS: The C. cardunculus n-ButOH fractions significantly restored levels of transaminases, triglycerides, cholesterol, LDL, glucose and uric acid. The n-ButOH fraction exerted an improving effect on the body and liver weight and liver index. It also significantly corrected the imbalance in liver MDA and GSH levels. The n-ButOH fractions further ameliorated abnormalities in liver histology through suppression of lipid droplets accumulation. CONCLUSION: This research proves that the flavonoid-rich fraction of C. cardunculus has protective activity against high fructose intake in mice via reversing hyperlipidemia and boosting liver antioxidant capacity.

Evaluation of anti-inflammatory, diuretic and oral glucose tolerance activities of phenolic compound-rich fractions of Hammada articulata in Albino Wistar rats.

Hammada articulata is a plant widely used by the locals of the Algerian Sahara for multiple medicinal purposes. However, little was known about its chemical composition and the mechanisms of its bioactivity. For this purpose, the derived extracts [chloroform (CHCl3), ethyl acetate (EtOAc) and n-butanol (n-BuOH)] of the 80% ethanol extract of its aerial parts, were evaluated for their anti-inflammatory, diuretic, and anti-hyperglycemic activities in vivo. A preliminary phytochemical screening of H. articulata extracts showed the presence of a variety of secondary metabolites. RP-HPLC/DAD was used to analyze some fractions obtained by fractionation of the three derived extracts, by column chromatography and chosen because of the abundance and simplicity of their chemical composition. The fractions obtained from EtOAc and n-BuOH extracts showed a particular richness in phenolic compounds mainly naringenin, quercetin, kaempferol, myricetin, and rutin, which were known for their many interesting biological activities. The three derived extracts from H. articulata were assessed for their anti-inflammatory activity in the carrageenan-induced edema model in rats and their diuretic activity using hydrochlorothiazide (HCTZ) as a diuretic reference. All extracts showed considerable anti-inflammatory activity; the highest was registered in the group treated with the n-BuOH extract. However, for the diuretic activity, only the chloroform extract was active, with a diuretic spectrum similar to that of the standard diuretic HCTZ. The anti-hyperglycemic effect was carried out on the three derived extracts administered orally at a dose of 200 mg/kg, using the glucose tolerance test after gavage with the extracts. The EtOAc and n-BuOH extracts showed significant anti-hyperglycemic activity, improving oral glucose tolerance in normal rats.

A new isoflavonoid derivative, evaluation of the antioxidant capacity and phenolic content of Genista lobelii DC.

The phytochemical investigation of both chloroform and ethyl acetate extracts of Genista lobelii DC from an Algerian endemic plant led to the isolation of a new isoflavonoid Aspalathoidin compound (1) and nine known compounds (laburnetin, isokaempferide, retamasin B, ephedrodin, sakuretin, isoprunetin, genistein -7-O-ß-glucoside, derrone-4'-O-methyl ether and eriodictyol-7,3'-dimethylether). Twelve phenolic compounds were identified in ethyl acetate and n-butanol extracts through a qualitative investigation of phenolic compounds using HPLC. Finally, both extracts were estimated for their phenolic and flavonoid contents as well as the evaluation of their antioxidant activity using five different assays DPPH, CUPRAC, ABTS, GOR and the sun protection factor SPF was determined as an index of the photoprotective capacity of the G.lobelii DC extracts. The extract of chloroform and ethyl acetate has good antioxidant and includes significant levels of phenolic and flavonoid components.

Neuroinflammation and Behavioral Deficit in Rotenone-Induced Neurotoxicity in Rats and the Possible Effects of Butanolic Extract of Centaurea africana.

BACKGROUND: Many studies have used rotenone (ROT) to create an experimental animal model of Parkinson's disease (PD) because of its ability to induce similar behavioral and motor deficits. PD is the most common age-related motoric neurodegenerative disorder. Neuroinflammation and apoptosis play an important role in the pathogenesis of this disease. OBJECTIVE: This study investigated the effect of butanolic (n-BuOH) extract of Centaurea africana (200 mg/kg, 16 days) on a ROT-induced neurotoxicity model in male Wistar albino rats. METHODS: Estimation of Tumor Necrosis Factor (TNF-α) and Nitric Oxide (NO) levels along with the myeloperoxidase (MPO) activity in brains was carried out in order to evaluate neuro-inflammation. Oxidative stress, Caspase 3 activity (apoptosis), and behavioral alterations were also evaluated. RESULTS: In behavior assessment, using Ludolph Movement Analysis Scale, all ROT treated animals showed a decreased locomotor activity. The mitochondrial dysfunction induced by ROT was expressed by a decreased activity of complex I of the mitochondrial respiratory chain and increased lipid peroxidation and caspase 3. Co-treatment with the n-BuOH extract significantly restored the activity of complex I (65.41 %) compared to treatment with ROT alone. The n-BuOH extract also reduced the neuroinflammation in rat brains by reducing MPO activity (75.12 %), NO levels (77.43 %), and TNF-α (71.48 %) compared to the group treated with ROT. CONCLUSION: The obtained results indicated that C. africana n-BuOH extract exhibited a protective effect in rats.

Phytochemical investigation of Volutaria lippii and evaluation of the antioxidant activity.

Volutaria lippii (L.) Cass. ex Maire, syn. Centaurea lippii (L.), (Asteraceae) is a plant from the central region of Algeria, considerably distributed in all Mediterranean areas. Herein, the antioxidant activity of the three derived fractions [chloroform (CHCl3), ethyl acetate (EtOAc) and n-butanol (n-BuOH)] of the 70% methanol extract of the aerial parts (leaves and flowers), was assessed by using CUPRAC, ABTS, DPPH free radical scavenging, and ß-carotene bleaching methods. The results obtained allowed to guide the fractionation of EtOAc and n-BuOH fractions by CC followed by purification by TLC and reverse phase HPLC. A guaianolide glucoside, 3ß-hydroxy-11ß,13-dihydrodehydrocostuslactone 8α-O-(6'-acetyl-ß-glucopyranoside) (1), never reported in the literature, was isolated together with other known compounds (2-14). Their structures were elucidated by the extensive use of 1 D- and 2 D-NMR experiments along with ESI-MS analyses and with comparison with literature data.

Essential oil constituents of Juniperus oxycedrus L. and Cupressus sempervirens L. (Cupressaceae) growing in Aures region of Algeria.

The purpose of this study was to determine the chemical composition of essential oils from the aerial parts of two species belonging to the Cupressaceae family growing in the Aures region of Algeria Juniperus oxycedrus and Cupressus Sempervirens. The analysis by GC-MS and GC-FID techniques showed the presence of 38 compounds in J. oxycedrus oil where the major constituents were manoyl oxide (23.5%), pentadecan-2-enone 6Z (12.6%), abietatriene (8.0%), abieta-8,11,13-triene-7-one (6.5%), cubebol (4.6%), epi-torilenol (3.8%) and α-cadinol (2.6%), while, a total of 65 compounds were showed in C. sempervirens oil where the major constituents were α-pinene (68.0%), epi-cedrol (6.1%), α-terpenyl acetate (3.5%) and germacrene D (2.5%). It is the first time that the compounds pentadecan-2-enone 6Z, abieta-8,11,13-trien-7-one, cubebol and epi-torilenol have been identified in our J. oxycedrus and epi-cedrol in C. sempervirens essential oils with high contents, as we noticed the absence of α-pinene in our J. oxycedrus essential oil.

Antioxidant, Anti-Inflammatory and Cytotoxic Properties of Centaurea africana Lamk var. [Bonnet] M].

BACKGROUND: In Algerian traditional medicine, Centaurea species are well known in traditherapy. Centaurea africana has been used in folk medicine for the treatment of several inflammatory disorders. OBJECTIVE: This study aims to examine the antioxidant, anti-inflammatory and anti-proliferative potential of both n-Butanol (BECA) and ethyl acetate (EAECA) extracts of Centaurea africana. METHODS: The phytochemical analysis of both BECA and EAECA were explored and the antioxidant activities were investigated by measuring the DPPH° scavenging effect, the reducing power and the inhibition of lipid peroxidation (LPO) induced by by Fe2+/ ascorbic acid system. The antiinflammatory properties were determined by measuring the NO° scavenging effect and by using carrageenan-induced rat paw oedema. The antiproliferative activity was studied on HT29 (human colorectal adenocarcinoma), OV2008 (human ovarian cancer) and C6 (Rattus norvegicus brain glioma) cell lines using the Sulforhodamine B assay. RESULTS: The total polyphenol contents (TPC) of EAECA and BECA are recorded at 125.24±10.14 and 53.03±2.50 mgGAE/g extract, respectively. Both extracts revealed the antioxidant activity in a concentration-dependent manner; this effect is more pronounced with EAECA. The BECA exhibited a higher anti-inflammatory activity. This anti-inflammatory activity was reflected in a reduction of swelling of carrageenan-evoked edemas (48.45 %), inhibition of nitric oxide (84.7 %), effective decrease in myeloperoxidase activity (58.82 %) and malondialdehyde level (65.58 %). The cytotoxic effect of BECA was found to be more pronounced against C6 cell lines (IC50 value: 131.93 µg/mL) while the cytotoxic activity of EAECA was more effective against HT29 and OV2008 cell lines. CONCLUSION: The obtained results indicated that EAECA exhibited a high antioxidant activity, while BECA has significant anti-inflammatory activity. Both extracts showed cytotoxic effects against cancer cell lines at certain concentrations in a cell-specific manner.

New sesquiterpenes from Asteriscus graveolens.

Asteriscus graveolens (Forsk) Less. is a Saharan medicinal plant of Asteraceae family. A new acyclic sesquiterpene [7,12-dihydroxy-6,7-dihydro-5,(6) E-dehydronerolidol (3)] and sesquiterpene germacranolide lactone derivatives [9ß-hydroxy-11ß,13-dihydroparthenolide-9-O-ß-D-glucopyranoside (7) and 9α-hydroxy-11ß,13-dihydroparthenolide-9-O-ß-D-glucopyranoside (8)] along with eight known compounds were isolated from polar extracts of aerial parts. Their structures were established by the analysis of 1 D- 2 D-NMR and high-resolution mass spectrometry data. A. graveolens extracts and compounds showed a significant (P < 0.05) and concentration dependent inhibitory effect on the growth of Human Colon Carcinoma (HCT116) and Human Colorectal Adenocarcinoma (DLD1) cells with IC50 in a concentration range from 89.4 to 296.0 µg/mL for extracts and from 32.6 to 728.1 µg/mL for compounds. No cytotoxic effects was evidenced in normal Primary Human Dermal Fibroblast (HDFa) up to 0.050 mg/mL for extracts and 1.0 mg/mL for pure compounds.

Polyphenolic content and bioactivities of Crataegus oxyacantha L. (Rosaceae).

Solid-Liquid Extraction (SLE) using solvent of different polarities (CHCl3, EtOAc, and n-BuOH) has been applied to leaves and fruits from (Crataegus oxyacantha L.), a deciduous shrub with an expected rich phytochemical profile. The total polyphenols content and the radical scavenging activity of each extract were evaluated. These extracts were analyzed by HPLC-DAD and rutin, quercetin-3-glucoside, caftaric and caffeic acid had been positively identified. The phytochemical study of the ethyl acetate extract of C. oxyacantha, led to the isolation and structural elucidation of quercetin (1); quercetin-3-O-ß-glucoside (2); epicatechin (3); naringenin (4), reported for the first time from this species except caffeic acid and epicatechin. These compounds were identified by 1D and 2D NMR combined analysis as well as by MS and UV.The antimicrobial activity of these extracts has also been tested, showing strong antibacterial activity-solvent dependent-against Gram positive bacteria. Additionally, bactericidal power was demonstrated in fruit extracts.

Apigenin rich-Limonium duriusculum (de Girard) Kuntze promotes apoptosis in HCT116 cancer cells.

The pro-apoptotic property of n-BuOH extract of Limonium duriusculum (BEL) and its major isolated components [apigenin (APG1) and apigenin7-O-ß-D-(6''-methylglucuronide) (APG2)] were tested. The anti-proliferative IC50 of BEL and APG1 was quantified as 7.60 µg/mL and 25.74 µM respectively, while APG2 did not affect cell proliferation in HCT116 p53 wild type cells. Growth inhibition by BEL treatment was associated with reduced signaling from the MAP kinase, activation of the p53 response pathway and PARP cleavage. The multi-effect of Limonium duriusculum could be due through their major apigenin compounds and the other bioactive constituents that may possibly act in synergy to exercise the most favorable anti-tumor activities.

Bio-guided isolation of leishmanicidal and trypanocidal constituents from Pituranthos battandieri aerial parts.

Protozoan pathogens that cause neglected tropical diseases are a major public health concern in tropical and developing countries. In the course of our ongoing search for new lead compounds as potential antiprotozoal agents, this study aims to perform a bio-guided fractionation of Pituranthos battandieri, using an in vitro assay against Leishmania amazonensis and Trypanosoma cruzi. Two known polyacetylenes, (-)-panaxydiol (1) and (-)-falcarindiol (2) were identified from the ethanolic extract of the aerial parts of P. battandieri as the main bioactive constituents. Compounds 1 and 2 showed similar potency (IC50 values of 5.76 and 5.68 µM, respectively) against L. amazonensis to miltefosine (IC50 value of 6.48 µM), the reference drug, and low toxicity on macrophage cell lines J774. Moreover, compound 1 exhibited moderate activity (IC50 23.24 µM) against T. cruzi. In addition, three known furanocoumarins, 8-geranyloxypsoralen (3), 8-geranyloxy-5-methoxypsoralen (4), and phellopterin (5) were isolated. Their structures were elucidated by NMR and MS analysis. Compounds 1 and 2 are described for the first time in the Pituranthos genus, and this is the first report on their antiprotozoal activity. These results highlight this type of polyacetylenes as an interesting scaffold for the development of novel antiparasitic drugs.

On-line screening and identification of polyphenolic antioxidant compounds of Convolvulus trabutianus.

Convolvulus trabutianus Schweinf. & Muschl. is an endemic plant from northern Sahara used in folk medicine. Herein we report, the isolation, characterization and evaluation of the radical scavenging properties of twenty three compounds from different extracts of this species by on-line HPLC-ABTS•+ screening. These compounds include nine phenolic acids: 2, 6, 10-16, two phytosterols: 3-4, four coumarins: 5, 7-9, two quinic acids: 21 and 22 and six flavonoids: 1, 17-20 and 23 among which the most active were: 10, 16, 21 and 22. All the extracts showed a significant antioxidant activity on-line. These results were validated off-line by ORAC and TEAC assays. Four compounds: 1, 5, 18 and 19 were described for the first time from the Convolvulaceae family, whereas compounds 2, 6, 8, 10, 13 and 21 were new for the genus Convolvulus.

Chemical composition, in vitro antiparasitic, antimicrobial and antioxidant activities of Frankenia thymifolia Desf.

This study was performed on the derived fractions [chloroform (FT-C), ethyl acetate (FT-E) and n-butanol (FT-B)] of the 70% ethanol extract prepared from Frankenia thymifolia, endemic to North Africa. The fractions showed high total phenolic and flavonoid contents particularly FT-E. These results agreed with their antioxidant effects. Indeed, all the fractions were able to scavenge 1,1-diphenyl-2-picrylhydrazyl radical, with a better power of FT-E. These results were supported by the inhibition of ß-carotene oxidation assay. The fractions showed moderate activity against Acanthamoeba castellanii and Leishmania amazonensis with a better activity of FT-E against A. castellanii. Moreover, FT-B exhibited an interesting antimicrobial activity against all tested bacteria. The phytochemical investigation of the most active fractions (FT-E and FT-B) led to the isolation and structural determination of six compounds. The observed biological activities may be associated with the presence of quercetin and its derivatives found in the chemical composition of these fractions.