Metabolites Profiling of Manilkara mabokeensis Aubrév Bark and Investigation of Biological Activities.

Manilkara mabokeensis Aubrév is a tree that belongs to the Sapotaceae family, native to the tropical forest in Latin America, Asia, Australia, and Africa. The bark of this species is used as traditional medicine to treat diseases. The present study is the first phytochemical investigation on M. mabokeensis Aubrév bark in terms of phytochemical composition and bioactivity. Among the different extracts, ethyl acetate (EtOAc) exhibited the highest values of total phenolic content (TPC), total flavonoid content (TFC), condensed tannin content (CTC), and reducing sugar content, as well as a high antioxidant activity. Interestingly, gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS) analysis were enabled to identify 23 compounds in the essential oil of M. mabokeensis Aubrév bark, which have not been previously described in the literature. Phytol and 8,14-cedranoxide were the major identified compounds, with area percentages of 27.9 and 18.8%, respectively. For HPLC analysis, 3,4-dihydroxy-benzoic acid methyl ester showed the highest concentration with 61.8 mg/g of dry residue (dr) among other identified molecules. Manilkara mabokeensis Aubrév bark MeOH extract showed a good anti-15-lipoxygenase (anti-15-LOX) and anti-acetylcholinesterase (anti-AChE) activities of 65.8 and 71.0%, respectively, while it exhibited a moderate antixanthine oxidase (anti-XOD) activity (41.5%) at 50 µg/mL. Furthermore, cyclohexane (CYHA) and ethyl acetate induced the highest cytotoxicity against the human ovarian cancer cell lines, OVCAR (49.5%) and IGROV (48.7%), respectively. Taken together, obtained results argue that M. mabokeensis Aubrév bark is an excellent source of natural compounds and justify its use in folk medicine.

Evaluation of in vitro biological activities: antioxidant; anti-inflammatory; anti-cholinesterase; anti- xanthine oxidase, anti-superoxyde dismutase, anti-α-glucosidase and cytotoxic of 19 bioflavonoids.

Pure compounds belonging to phenolic family were studied for their biological potential such as 5,8-dihydroxy-1,4-naphthoquinone (M1), rutin hydrate (M2), 2,3-dichloro-5,8-dihydroxy-1,4-naphthoquinone (M3), taxifolin (M4), myricetin (M5), plumbagin (M6), silibinin (M7), dihydromyricetin (M8), shikonin (M9), quercetin 3-ß-D-glucoside (M10), (±)-taxifolin hydrate (M11), cardamonin (M12),(-)-epicatechin (M13), 9-chloro-10-hydroxy-anthracene-1,4-dione (M14), 9-chloro-10-hydroxy-2,3-dimethyl-anthracene-1,4-dione (M15), 2-chloro-3-(2-hydroxy-5-methylanilino)-1,4-naphthoquinone (M16), 2-chloro-3-(4-hydroxy-phenylamino)-(1,4) naphthoquinone (M17), 2-chloro-3-(3,5-di-tert-butyl-4-hydroxy-phenyl)-(1,4)-naphtoquinone (M18), and myricitrin dihydrate (M19). These molecules were chosen based on two reasons; the limited or total absence of their exploitation in several studied activities and the use of other tests for the same activity. The evaluation of the in vitro anti-acetyl-cholinesterase (AChE), anti-5-lipoxygenase (5-LOX), anti-xanthine oxidase (XOD), anti-alpha glucosidase, anti-superoxide dismutase (SOD), anti-oxidant (DPPH (1, 1-diphenyl-2-picrylhydrazyl) and ABTS (2, 2- azinobis-3-ethylbenzothiazoline-6-sulphonate)), and anticancer activities of mentioned 19 molecules was explored during this work. M3, M14, M15, M16, M17, M18, M19 were exploited for the first time for such purposes. Tested compounds were shown to have interesting radical scavenging abilities against DPPH radicals, and the highest molecules among them were M19 and M5 (IC50 = 12.0 and 15.5 µM, respectively), and M4, M19 and M2 against ABTS (IC50= 1.9, 4.3 and 4.3 µM, respectively). Moreover, the majority of products showed very important cytotoxic activity since IC50 values were ranging between (IC50= 0.2 µM (M1) and 79 µM (M8)) against HCT116 cell line, and values of IC50= 0.2 µM for M1 against MCF7 cell line. All new molecules (non studied before) were shown to have great cytotoxic effect against both cancer cell lines.Furthermore, molecule M5 was shown to have anti-inflammatory potential via the inhibition of 5-LOX enzyme (65% at 100 µM). In addition, M19 showed important anti XOD activity with 47% of inhibition at 100 µM. Also, it has been found that compound M3 had the best anti alpha glucosidase activity with 43.8 % of inhibition at 100 µM, the highest anti-AChE effect (IC50= 14.5 µM), and the best effect towards SOD (IC50= 10.0 µM).  A structure-activity relationship study was also performed.

The impact of regional locality on chemical composition, anti-oxidant and biological activities of Thymelaea hirsuta L. extracts.

BACKGROUND: Thymelaea hirsuta L. is a medicinal plant endemic to Tunisia, commonly used for its biological properties in traditional medicinal. PURPOSE: This study reports, to the best of our knowledge for the first time, the effect of regional location on the chemical composition, anti-oxidant and biological activities of organics extracts obtained from aerial parts of T. hirsuta. METHODS/STUDY DESIGN: The aerial parts collected from different locations were prepared by sequential method with solvents of increasing polarity namely hexane, ethyl acetate, ethanol and methanol. An assessment of the anti-oxidant properties of all extracts was performed using DPPH and ABTS+ assays. We also investigated the anti-cholinesterase, anti-xanthine oxidase and cytotoxic (against MCF-7 and OVCAR) activities. RESULTS: The study of the phytochemical composition showed that the extracts are rich in phenolics (5.38-315.65 mg GAE/g dw) and tannin (0.7-73.8 mg CE/g dw). Also, the results showed that the chemical composition as well as the biological activities varies considerably between regions. The DPPH and ABTS+ assays revealed that the highest important antioxidant activity was in the methanolic extract for all localities (IC50: 14.8-16.5 mg/l and 6.4-22.23 mg/l, respectively). However, the various extracts had moderate anti-cholinesterase activity (7.52-45.36%) at 50 mg/l. Regarding the xanthine oxidase inhibitory activity, ethyl acetate extract exhibited a moderate activity at a 50 mg/l. The highest cytotoxic activity against MCF-7 and OVCAR was recorded in the ethyl acetate extract of Fernana region (70.1% and 70.8% inhibition at 50 mg/l, respectively). The analysis of HPLC-UV indicates the presence of several phenolic compounds in different extracts of T. hirsuta, possibly accounting for its biological properties. CONCLUSION: The phenolic contents were highly correlated to anti-oxidant activity with very high correlation coefficient (R2) values. The findings show that the extracts are rich in antioxidant compounds and this plant may be used as a natural source of bioactive compounds with high anti-oxidant and potential anticancer activities.

Bioactive flavones isolated from Tunisian Artemisia campestris L. Leaves.

Four flavones were isolated from dried leaves of Artemisia campestris L. 2',4',5,7-tetrahydroxy-5',6-dimethoxyflavone, eupatilin and dimethoxycentaureidin were reported for the first time in this species whereas cirsiliol was previously identified but it was isolated for the first time. Their structures were elucidated by spectroscopic methods, including 1D and 2D NMR experiments and mass spectrometry analysis. In addition, all isolated flavones were evaluated for their antioxidant, anti-inflammatory, anti-superoxide dismutase, anti-xanthine oxidase and cytotoxic activities. The results showed that all isolated compounds exhibited potent anti-xanthine oxidase activity with IC50 ranging from 3.3 to 6.8 µM, which was higher than that of the control compound allopurinol (8.2 ± 0.6 µM). In addition, cirsiliol was found to be the most cytotoxic against OVCAR-3, IGROV-1and HCT-116 cell lines at 15µM, with inhibition percentage values of 53.7, 48.8 and 40.9%, respectively. All compounds also showed weak to moderate anti-inflammatory and anti-superoxide dismutase activities.

Chemical composition and biological activities of extracts and essential oil of Boswellia dalzielii leaves.

CONTEXT: Boswellia dalzielii Hutch. (Burseraceae) is an aromatic plant. The leaves are used for beverage flavouring. OBJECTIVE: This study investigates the chemical composition and biological activities of various extracts. MATERIALS AND METHODS: The essential oil was prepared via hydrodistillation. Identification and quantification were realized via GC-MS and GC-FID. Consecutive extractions (cyclohexane, dichloromethane, ethyl acetate and methanol) were carried out and various chemical groups (phenolics, flavonoids, tannins, antocyanins and sugar) were quantified. The volatile compounds of organic extracts were identified before and after derivatization. Antioxidant, antihyperuricemia, anti-Alzheimer, anti-inflammatory and anticancer activities were evaluated. RESULTS: In the essential oil, 50 compounds were identified, including 3-carene (27.72%) and α-pinene (15.18%). 2,5-Dihydroxy acetophenone and ß-d-xylopyranose were identified in the methanol extract. Higher phenolic (315.97 g GAE/kg dry mass) and flavonoid (37.19 g QE/kg dry mass) contents were observed in the methanol extract. The methanol extract has presented remarkable IC50 = 6.10 mg/L for antiDPPH, 35.10 mg/L for antixanthine oxidase and 28.01 mg/L for anti-5-lipoxygenase. For acetylcholinesterase inhibition, the best IC50 (76.20 and 67.10 mg/L) were observed, respectively, with an ethyl acetate extract and the essential oil. At 50 mg/L, the dichloromethane extract inhibited OVCAR-3 cell lines by 65.10%, while cyclohexane extract inhibited IGROV-1 cell lines by 92.60%. DISCUSSION AND CONCLUSION: Biological activities were fully correlated with the chemical groups of the extracts. The ethyl acetate and methanol extracts could be considered as potential alternatives for use in dietary supplements for the prevention or treatment of diseases because of these extracts natural antioxidant, antihyperuricemic and anti-inflammatory activities.

Antioxidant, 5-lipoxygenase inhibitory and cytotoxic activities of compounds isolated from the Ferula lutea flowers.

A phytochemical investigation of the Ferula lutea (Poir.) Maire flowers has led to the isolation of a new compound, (E)-5-ethylidenefuran-2(5H)-one-5-O-ß-d-glucopyranoside (1), designated ferunide, 4-hydroxy-3-methylbut-2-enoic acid (2), reported for the first time as a natural product, together with nine known compounds, verbenone-5-O-ß-d-glucopyranoside (3), 5-O-caffeoylquinic acid (4), methyl caffeate (5), methyl 3,5-O-dicaffeoylquinate (6), 3,5-O-dicaffeoylquinic acid (7), isorhamnetin-3-O-α-l-rhamnopyranosyl(1→6)-ß-d-glucopyranoside, narcissin (8), (-)-marmesin (9), isoimperatorin (10) and 2,3,6-trimethylbenzaldehyde (11). Compounds 3-10 were identified for the first time in Ferula genus. Their structures were elucidated by spectroscopic methods, including 1D and 2D NMR experiments, mass spectroscopy and X-ray diffraction analysis (compound 2), as well as by comparison with literature data. The antioxidant, anti-inflammatory and cytotoxic activities of isolated compounds were evaluated. Results showed that compound 7 exhibited the highest antioxidant activity with IC50 values of 18 ± 0.5 µmol/L and 19.7 ± 0.7 µmol/L by DPPH radical and ABTS radical cation, respectively. The compound 6 exhibited the highest anti-inflammatory activity with an IC50 value of 5.3 ± 0.1 µmol/L against 5-lipoxygenase. In addition, compound 5 was found to be the most cytotoxic, with IC50 values of 22.5 ± 2.4 µmol/L, 17.8 ± 1.1 µmol/L and 25 ± 1.1 µmol/L against the HCT-116, IGROV-1 and OVCAR-3 cell lines, respectively.

Chemical composition, biological and cytotoxic activities of plant extracts and compounds isolated from Ferula lutea.

The present work describes the phytochemical study on Ferula lutea flowers. Total phenolics and flavonoids of the n-butanol and ethyl acetate extracts were quantified (phenolics [40.68-52.29 mg gallic acid equivalent/g of dry weight], flavonoids [12.38-14.72 mg quercitin/g dry weight]). Two diastereoisomers were isolated and identified using spectroscopic techniques (1D, 2D NMR and GC-MS). The extracts and diastereoisomers were tested for antioxidant, antiacetylcholinesterase, antimicrobial, antidiabectic, cytotoxic (leukemia cell line) activities and allelopathic potentialities. The strongest antioxidant activity was obtained for the ethyl acetate extract (IC50 = 12.8 ± 1.29 µg/mL). The two extracts exhibited high antidiabetic activity (54.1 and 52.1% at 40 µg/mL).

Comparison between supercritical CO2 extraction and hydrodistillation for two species of eucalyptus: yield, chemical composition, and antioxidant activity.

In this work, 2 Eucalyptus species extracts (Eucalyptus cinerea and Eucalyptus camaldulensis) were prepared by hydrodistillation (HD) and supercritical carbon dioxide extraction (SCE) techniques. The best yields of E. cinerea and E. camaldulensis (27.5 and 8.8 g/kg, respectively) were obtained using SCE at 90 bar, 40 °C compared to HD (23 and 6.2 g/kg, respectively). Extracts were quantified by gas chromatography-flame ionization detection and identified by gas chromatography-mass spectrometry. 1,8-cineole and p-menth-1-en-8-ol were the major compounds of E. cinerea essential oil obtained by HD (64.89% and 8.15%, respectively) or by SCE (16.1% and 31.87%, respectively). Whereas, in case of E. camaldulensis, 1,8-cineole (45.71%) and p-cymene (17.14%) were the major compounds obtained by HD, and 8,14-cedranoxide (43.79%) and elemol (6.3%) by SCE. Their antioxidant activity was assessed using 2 methods: 2,2-azino-di-3-ethylbenzothialozine-sulphonic acid radical cation (ABTS(•+) ) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(•) ). In the SCE extracts from both E. cinerea and E. camaldulensis, a promising radical scavenging activity was observed with ABTS(•+) , (65 and 128 mg/L, respectively). The total phenolics composition of the extracts was measured and the range was 2 to 60 mg of gallic acid equivalent/g dry plant material. The SCE method was superior to HD, regarding shorter extraction times (30 min for SCE compared with 4 h for HD), a low environmental impact, allows production of nondegraded compounds and being part of green chemistry.

Global chemical composition and antioxidant and anti-tuberculosis activities of various extracts of Globularia alypum L. (Globulariaceae) leaves.

In this work, an evaluation of the biological activities of Globularia alypum L. extracts and their global chemical composition was realized. Extracts from G. alypum were obtained by two extraction methods. The composition of polyphenols (8.5-139.95 g gallic acid equivalent/Kg of dry mass), tannins (1.39-18.65 g catechin equivalent/Kg of dry mass), anthocyanins (8.17-70.69 mg cyanidin equivalent/Kg of dry mass) and flavonoids (0.31-19.28 g quercetin equivalent/Kg of dry mass) was evaluated. The samples were subjected to a screening for their antioxidant activities using the DPPH* and ABTS*+ assays. For the first time, the anti-tuberculosis activity (H(37)Rv) for G. alypum was tested against Mycobacterium tuberculosis. The strongest antioxidant activity was obtained for the methanol extract (IC(50 ) = 15.58 ± 0.168 mg/L) and the best anti-tuberculosis activity was obtained for the petroleum ether extract (IC(50 )= 77 mg/L). We have found a positive correlation between the total phenolics content and the antioxidant activity R2 = 0.88 (DPPH*) and R2 = 0.97 (ABTS*+). We have found also a positive correlation between the flavonoid content and the antioxidant activity R2 = 0.91 (DPPH*) and R2 = 0.91 (ABTS*+).

Influence of the process, season, and origin on volatile composition and antioxidant activity of Juniperus phoenicea L. leaves essential oils.

Essential oils of Juniperus phoenicea L. leaves cultivated in 3 regions, Korbos, Matmata, and Tabarka of Tunisia were obtained by hydrodistillation (HD), steam distillation (SD), and Soxhlet (SH) extraction methods. The essential oils were analyzed and quantified by capillary gas chromatography using flame ionization detection (GC-FID) and mass spectrometry (GC-MS). The highest yield was observed in HD process (1.12%). Tabarka essential oil provided the best yield 0.79% compared to other regions. December month SD essential oil was the highest in oxygenated monoterpenes (52.7%). Nevertheless, SH essential oil showed a higher content in sesquitepenes hydrocarbons (64.5%). α-Terpinol (25.5%) was the main oxygenated component in Matmata juniper essential oil, extracted by SD. Moreover, the antioxidant activity of essential oils was evaluated using ABTS assays. The strongest antioxidant activity (IC(50) = 22.6 ± 0.7 mg/L) was obtained by the Matmata (October 2007) SD essential oil.

Chemical composition and anticancer and antioxidant activities of Schinus molle L. and Schinus terebinthifolius Raddi berries essential oils.

Essential oils were obtained by steam distillation from berries of Schinus molle L. and Schinus terebinthifolius Raddi originating from southern of Tunisia and analyzed by GC-FID and GC-MS. Among 57 and 62 compounds (%[mg/100 g dry matter]) identified in these oils, the main were alpha-phellandrene (46.52%[1256.15] and 34.38%[859.60]), beta-phellandrene (20.81%[561.74] and 10.61%[265.15]), alpha-terpineol (8.38%[226.26] and 5.60%[140.03]), alpha-pinene (4.34%[117.29] and 6.49%[162.25]), beta-pinene (4.96%[133.81] and 3.09%[77.30]) and p-cymene (2.49%[67.28] and 7.34%[183.40]), respectively. A marked quantity of gamma-cadinene (18.04%[451.05]) was also identified in the S. terebinthifolius essential oil whereas only traces (0.07%[1.81]) were detected in the essential oil of S. molle. The in vitro antioxidant and antiradical scavenging properties of the investigated essential oils were evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Essential oil of S. terebinthifolius expressed stronger antioxidant activity in the ABTS assay, with an IC(50) of 24 +/- 0.8 mg/L, compared to S. molle (IC(50)= 257 +/- 10.3 mg/L). Essential oils were also evaluated for their anticancer activities against human breast cancer cells (MCF-7). S. terebinthifolius essential oil was more effective against tested cell lines (IC(50)= 47 +/- 9 mg/L) than that from S. molle (IC(50)= 54 +/- 10 mg/L). Suggestions on relationships between chemical composition and biological activities are outlined.