Berberis aetnensis and B. libanotica: a comparative study on the chemical composition, inhibitory effect on key enzymes linked to Alzheimer's disease and antioxidant activity.

OBJECTIVES: This study involves for the first time the evaluation of Berberis aetnensis C. Presl. and Berberis libanotica Ehrenb. ex C.K. Schneid. roots for anticholinesterase and antioxidant properties, with the aim to search compounds possibly useful for the treatment of Alzheimer's disease (AD). METHODS: Samples were evaluated for their ability to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The antioxidant activity was assayed by 2,2-diphenyl-1-picrylhydrazyl radical and ß-carotene bleaching tests. Berberine and palmatine were isolated by flash chromatography and identified by spectrometric methods as main constituents. Non-polar compounds were analysed by gas chromatography and gas chromatography-mass spectrometry. KEY FINDINGS: Extracts, fractions and isolated compounds inhibited AChE and BChE to varying degrees. The methanol fractions exhibited the strongest AChE inhibitory activity with inhibitory concentration 50% (IC50 ) of 7.6 and 16.9 µg/ml for B. aetnensis and B. libanotica, respectively. The alkaloid fraction of B. aetnensis inhibited AChE (IC50 of 24.5 µg/ml) and possessed the highest antioxidant activity (IC50 value of 2.2 µg/ml in ß-carotene-bleaching test after 30 min of incubation). Berberine was more potent of palmatine against AChE (IC50 of 2.2 and 7.4 µg/ml, respectively). CONCLUSIONS: These findings raise the possibility of developing B. aetnensis and B. libanotica as a promising candidate for the treatment of AD.

Antioxidant and anti-cholinesterase activity of Globularia meridionalis extracts and isolated constituents.

The antioxidant and anti-cholinesterase properties of Globularia meridionalis (Podp.) O. Schwarz (Globulariaceae) were investigated. G. meridionalis aerial parts and roots were extracted with methanol, and the total extract successively partitioned with n-hexane. The methanol fraction of the roots showed the highest antioxidant activity with IC50 values of 8.0 and 2.1 microg/mL in the DPPH and beta-carotene bleaching tests, respectively. From this fraction, three flavonoids, namely pectolinarigenin 7-O-beta-glucoside, apigenin 7-O-beta-glucoside and luteolin, and two phenylethanoids, namely acteoside and isoacteoside, were isolated. Potential anti-cholinesterase effects were assessed through the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibition assay. The n-hexane fraction of the roots exhibited the highest activity against both AChE and BChE with IC50 values of 65.5 and 70.4 microg/mL, respectively.

Evaluation of Citrus aurantifolia peel and leaves extracts for their chemical composition, antioxidant and anti-cholinesterase activities.

BACKGROUND: The replacement of synthetic antioxidants by safe natural antioxidants fosters research on the screening of vegetables and food as sources of new antioxidants. Moreover, oxidative degeneration of cells is associated with neurodegenerative diseases such as Alzheimer's disease. On the basis of these considerations this work aimed to investigate the antioxidant properties [by using the diphenyl picryl hydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric reducing ability of plasma assays, and the ß-carotene bleaching test] and the anti-cholinesterase activity of Citrus aurantifolia peel and leaves from different areas of growth. RESULTS: Methanol extracts of the peel and leaves demonstrated the strongest radical scavenging activity. A similar trend was observed with the reducing ability, with values from 112.1 to 146.0 µmol L(-1) Fe(II) g(-1). The relationship between phenol and flavonoid contents and antioxidant activity was statistically investigated. Based on analysis by high-performance liquid chromatography, the most abundant flavonoids found in C. aurantifolia extracts were apigenin, rutin, quercetin, kaempferol and nobiletin. n-Hexane fractions of both peel and leaves showed a good acetylcholinesterase inhibitory activity with IC(50) values in the range 91.4-107.4 µg mL(-1). Gas chromatography-mass spectrometry analysis revealed the presence of monoterpenes and sesquiterpenes as most common components. CONCLUSION: The findings of this study suggest a potential use of C. aurantifolia peel and leaves for supplements for human health.

Comparative study on the antioxidant capacity and cholinesterase inhibitory activity of Citrus aurantifolia Swingle, C. aurantium L., and C. bergamia Risso and Poit. peel essential oils.

UNLABELLED: The interest in medicinal plant research and in the aroma-therapeutic effects of essential oils in humans has increased in recent years, especially for the treatment of pathologies of relevant social impact such as Alzheimer's disease. The present study was taken up to evaluate the antioxidant capacity and the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity of the peel essential oils from three Citrus species, C. aurantifolia Swingle, C. aurantium L., and C. bergamia Risso & Poit. Essential oils were analyzed by GC and GC-MS and they contain mainly limonene, α-pinene, ß-pinene, γ-terpinene, and linalyl acetate. C. aurantifolia oil showed the highest radical scavenging activity on ABTS assay (IC50 value of 19.6 µg/mL), while C. bergamia exhibited a good antioxidant activity evaluated by the ß-carotene bleaching test (IC50 = 42.6 µg/mL after 60 min of incubation). C. aurantifolia inhibited more selectively AChE. Obtained data suggest a potential use of Citrus oils as a valuable new flavor with functional properties for food or nutraceutical products with particular relevance to supplements for the elderly. PRACTICAL APPLICATION: The demonstrated antioxidant activity and procholinesterase properties of Citrus essential oils suggested their use as a new potential source of natural antioxidant to added as extra-nutrient for using in food industries as a valuable new flavor with functional properties for food or nutraceutical products with particular relevance to supplements for the elderly.

Changes in the phenolic and lipophilic composition, in the enzyme inhibition and antiproliferative activity of Ficus carica L. cultivar Dottato fruits during maturation.

Fruits of Ficus carica cultivar Dottato from Italy were examined to assess how the stage of ripeness influences their chemical composition, antioxidant activity, pancreatic lipase inhibition and antiproliferative properties on C32 melanoma cells. Fruits of the first harvest (June) showed a major content in furanocoumarins and pyranocoumarins whereas the fruits collected in September showed the highest polyphenolic content (11.9 mg/g of dried material). The total 70% ethanol extracts were portioned between methanol/water and n-hexane, dichloromethane and ethyl acetate, successively. Coumarins and fatty acid esters were the most abundant components of the n-hexane fractions. The dichloromethane fractions showed as major components 2 furanocoumarins (rutarenin and pimpinellin). The total extracts of F. carica cv. Dottato exhibited a significant dose-dependent antiradical and inhibition of lipid peroxidation activity, particularly fruits of the first harvest (June) that showed the highest activity with IC50 of 1.64 mg/mL and 0.004 mg/mL, respectively. Among single fractions, the ethyl acetate fraction from the second harvest (July) showed the highest antiradical activity with an IC50 value of 0.05 mg/mL while the dichloromethane fraction showed the best inhibition of lipid peroxidation with an IC50 value of 0.02 mg/mL. Dichloromethane fractions showed the highest photodynamic cytotoxicity with an IC50<5 µg/mL.

Wild Mediterranean dietary plants as inhibitors of pancreatic lipase.

Lipids are essential compounds for all living organisms. Agents that inhibit fat digestion are of theoretical benefit in the treatment of obesity. A total of 18 species (21 hydroalcoholic extracts) of edible plants from Calabria region (Italy) were evaluated for their in vitro pancreatic lipase inhibitory activity. Lipase activity was measured by monitoring the hydrolysis of p-NPC, which releases the yellow chromogen, p-nitrophenol. The aqueous ethanol extracts of Portulaca oleracea (leaves) and Silene vulgaris (leaves) exhibited the strongest inhibitory effect on lipase. The amounts of total phenolics, measured by Folin-Ciocalteu method, varied widely in the different analysed extracts and ranged from 29 to 482 mg/g of extract. In this study, the findings do not show any relationship between lipase inhibitory activity and total phenolic content.

Anthemis wiedemanniana essential oil prevents LPS-induced production of NO in RAW 264.7 macrophages and exerts antiproliferative and antibacterial activities in vitro.

Anthemis wiedemanniana is known in folk medicine for the treatment of microbial infections, cancer and also urinary and pulmonary problems. In this study, the chemical composition of the essential oil from A. wiedemanniana was evaluated and its antibacterial activity was tested against 10 bacterial strains. The oil was also tested for its potentiality to inhibit nitric oxide production in RAW 264.7 macrophages and for its cytotoxicity against four human cancer cell lines. A. wiedemanniana oil, rich of oxygenated monoterpenes (25.4%), showed a good antibacterial activity against Gram-positive bacteria and a good activity against the two Gram-negative bacteria, Escherichia coli and Proteus vulgaris. Besides that, it exhibited a high inhibitory effect on the LPS-induced nitrite production and a strong cytotoxic activity, especially against amelanotic melanoma (C32) and large lung cell carcinoma (COR-L23) cell lines.

Comparative chemical composition and antioxidant activity of Calamintha nepeta (L.) Savi subsp. glandulosa (Req.) Nyman and Calamintha grandiflora (L.) Moench (Labiatae).

The two studied Calamintha species showed different polyphenolic content and sterol composition. Calamintha grandiflora possessed twice the polyphenolic content of Calamintha nepeta subsp. glandulosa, while the latter contained a higher number of sterols. Among them, stigmast-5-en-3ß-ol was found to be the major constituent. The methanolic extract of C. grandiflora was more potent than the C. nepeta subsp. glandulosa methanolic extract in a DPPH assay, while the activity of the C. grandiflora EtOAc fraction was weaker than its C. nepeta subsp. glandulosa counterpart. Fractions of C. nepeta subsp. glandulosa showed higher activity using a ß-carotene bleaching test. The petrol ether fraction of C. grandiflora showed significant inhibition of NO production.

Studies on the potential antioxidant properties of Senecio stabianus Lacaita (Asteraceae) and its inhibitory activity against carbohydrate-hydrolysing enzymes.

This study showed for the first time the antioxidant and hypoglycaemic properties of the methanol, n-hexane and ethyl acetate extracts from Senecio stabianus Lacaita, a plant that belongs to the Asteraceae family. The antioxidant activities were carried out using two different in vitro assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) test and 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonate) (ABTS) test. The ethyl acetate extract showed the highest activity with inhibitory concentration 50% (IC(50)) values of 35.5 and 32.7 µg mL(-1) on DPPH test and ABTS test, respectively. This activity may be related to a good total phenol and flavonoid content. All extracts were also tested for their potential inhibitory activity of α-amylase and α-glucosidase digestive enzymes. The n-hexane extract exhibited the highest α-amylase inhibition with an IC(50) value of 0.21 mg mL(-1). Through bioassay-guided fractionation processes seven fractions (A-G) were obtained and tested. Based on the phytochemical analysis, the activity of n-hexane extract may be related to the presence of monoterpenes and sesquiterpenes.

Antioxidant and antiproliferative activity of Laurus nobilis L. (Lauraceae) leaves and seeds essential oils against K562 human chronic myelogenous leukaemia cells.

The antioxidant and antiproliferative activities of the essential oils from Laurus nobilis leaves and seeds in relation to their composition were analysed. The most abundant components of the leaf essential oil were 1,8-cineole, 1-p-menthen-8-ethyl acetate, linalool and sabinene, while the seed oil was characterised by ß-ocimene, 1,8-cineole, α-pinene and ß-pinene as main constituents. Both seed and leaf essential oils exhibited a scavenging effect on the DPPH radical, with IC50 values of 66.1 and 53.5 µg mL⁻¹, respectively. The leaf essential oil showed the strongest antioxidant activity in the ß-carotene/linoleic acid system, with an IC50 value of 35.6 µg mL⁻¹ after 30 min of incubation. Both leaf and seed oils inhibited proliferation of the K562 tumour cell line with IC50 values of 95 and 75 µg mL⁻¹, respectively. The L. nobilis leaf oil showed a percentage of erythroide differentiation of 15% at a concentration of 10 µg mL⁻¹. A value of 12% was found for the seed essential oil at a concentration of 50 µg mL⁻¹. When the oils were added to a suboptimal concentration of the commercial drug, cytosine arabinoside, a clear synergic effect was observed.

Comparative study on the chemical composition, antioxidant properties and hypoglycaemic activities of two Capsicum annuum L. cultivars (Acuminatum small and Cerasiferum).

The present study aimed to evaluate for the first time the phenols, flavonoids, carotenoids, capsaicin and dihydrocapsaicin content and the antioxidant and hypoglycemic properties of Capsicum annuum var. acuminatum small and C. annuum var. cerasiferum air-dried fruits. The ethanol extract of C. annuum var. acuminatum small, characterized by the major content of total poliphenols, flavonoids, carotenoids and capsaicinoids, showed the highest radical scavenging activity (IC(50) of 152.9 µg/ml). On the contrary, C. annuum var. cerasiferum showed a significant antioxidant activity evaluated by the ß-carotene bleaching test (IC(50) of 3.1 µg/ml). The lipophilic fraction of both C. annuum var. acuminatum and C. annuum var. cerasiferum exhibited an interesting and selective inhibitory activity against α-amylase (IC(50) of 6.9 and 20.1 µg/ml, respectively).

In vitro cytotoxic activity of extracts and isolated constituents of Salvia leriifolia Benth. against a panel of human cancer cell lines.

In the course of recent efforts to identify new potential antiproliferative active principles, Salvia leriifolia extracts and isolated constituents were evaluated for their cytotoxic activity against a panel of human cancer cell lines, including renal adenocarcinoma (ACHN), amelanotic melanoma (C32), colorectal adenocarcinoma (Caco-2), lung large cell carcinoma (COR-L23), malignant melanoma (A375), lung carcinoma (A549), and hepatocellular carcinoma (Huh-7D12) cells. The hexane and CH(2) Cl(2) extracts showed the strongest cytotoxic activity against the C32 cell line with IC(50) values of 11.2 and 13.6 µg/ml, respectively, and the AcOEt extract was the most active extract against the COR-L23 cell line (IC(50) of 20.9 µg/ml). Buchariol, a sesquiterpene obtained by biofractionation of the CH(2) Cl(2) extract, exhibited a higher activity than the positive control vinblastine against the C32 and A549 cell lines (IC(50) values of 2.1 and 12.6 µM, resp.). Interesting results were also obtained for naringenin, a flavonoid isolated from the AcOEt extract, which exhibited a strong cytotoxic activity against the C32, LNCaP, and COR-L23 cell lines (IC(50) values of 2.2, 7.7, and 33.4 µM, resp.), compared to vinblastine (IC(50) values of 3.3, 32.2, 50.0 µM, resp.). None of the tested compounds affected the proliferation of skin fibroblasts (142BR), suggesting a selective activity against tumor cells.

In vitro antioxidant and hypoglycemic activities of Ethiopian spice blend Berbere.

The metal chelating activity, antioxidant properties, and the effect on carbohydrate-hydrolyzing enzymes of Ethiopian spice blend Berbere have been investigated. Berbere contains a total amount of phenols corresponding to 71.3 mg chlorogenic acid equivalent per gram of extract and a total flavonoid content of 32.5 mg quercetin equivalent per gram of extract. An increase of the resistance towards forced oxidation was obtained when Berbere was added to sunflower oil. In order to evaluate the bioactivity of the non-polar constituents, an n-hexane extract was obtained from Berbere. The gas chromatography-mass spectrometry analysis revealed the presence of 19 fatty acids constituents (98.1% of the total oil content). Among them, linoleic acid was the major component (72.0% of the total lipids). The ethanolic extract had the highest ferric-reducing ability power (35.4 µM Fe(II)/g) and DPPH scavenging activity with a concentration giving 50% inhibition (IC(50)) value of 34.8 µg/ml. Moreover, this extract exhibited good hypoglycemic activity against α-amylase (IC(50) = 78.3 µg/ml). In conclusion, Ethiopian spice blend Berbere showed promising antioxidant and hypoglycemic activity via the inhibition of carbohydrate digestive enzymes. These activities may be of interest from functional point of view and for the revalorization of the spice blend in gastronomy also outside the African country.

Phytochemical profile, antioxidant, anti-inflammatory and hypoglycemic potential of hydroalcoholic extracts from Citrus medica L. cv Diamante flowers, leaves and fruits at two maturity stages.

Since the past decade consumption of certain foods has been reported to have a positive effect on health. The object of the study was to determine for the first time the chemical composition and the antioxidant, anti-inflammatory and hypoglycemic potential of Citrus medica L. cv Diamante flowers, leaves and fruits (endocarp and mesocarp) at two maturity stages. Flowers and leaves were characterized by the highest total phenols and flavonoids content. A declining trend was observed during maturity of fruits for both phenols and flavonoids. The antioxidant activity evaluated by the ß-carotene bleaching test showed a strong activity for flowers and endocarp of mature fruits with IC50 values of 2.8 µg/mL and 3.5 µg/mL, respectively, after 30 min of incubation. Interestingly, the mature fruits endocarp (IC50 value of 426.0 µg/mL) could inhibit α-amylase with an IC50 value 2-fold higher than immature fruits. None of the tested extracts affected the proliferation of human skin fibroblasts 142BR. The obtained results suggest a potential use of C. medica L. cv Diamante as new valuable Citrus species with functional properties for food or nutraceutical product on the basis of high content of phytochemicals.

Chemical composition and protective effect of oregano (Origanum heracleoticum L.) ethanolic extract on oxidative damage and on inhibition of NO in LPS-stimulated RAW 264.7 macrophages.

The present study shows the chemical profile and the in vitro properties (antioxidant and inhibition of nitric oxide production) of the Origanum heracleoticum L. (Lamiaceae). The ethanolic extract of the aerial parts is characterized by terpenes and fatty acids. The extract, with high total phenol and flavonoid content, showed a significant radical-scavenging activity (IC(50) value of 12.8 µg/mL) using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test and an interesting antioxidant activity with the ß-carotene bleaching test (IC(50) values of 12.9 and 14.1 µg/mL at 30 and 60 min of incubation, respectively). The test for the inhibition of NO production, performed using the murine monocytic macrophage RAW 264.7 cell line, showed that the extract had significant activity with an IC(50) value of 108.5 µg/mL. The cytotoxic effect of O. heracleoticum extract in presence of lipopolysaccharide (LPS) (1 µg/mL) was evaluated but found to be negligible.

Correlation between environmental factors, chemical composition, and antioxidative properties of caper species growing wild in Calabria (South Italy).

Twenty samples of two caper species were collected from various natural habitats of Calabria (South Italy). A sample program was designed in order to cover all taxa and morphotypes present in the studied area, trying to correlate ecological conditions, phytochemical content, and biological activities. These species were characterized through the detection, isolation, and capillary GC-GC/MS quantitative evaluation of chemical markers (phytosterols and vitamin E). The antioxidant activity of MeOH caper extracts was assayed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ß-carotene bleaching tests. The chemical investigation showed a different composition according to the species and the populations. The best free radical (DPPH) scavenging activity was exerted by Capparis orientalis sample C4 (collected near Copanello village, granodiorite sea cliff) and Capparis sicula ssp. sicula sample C5 (collected near Tarsia village, clay soil). Sample C2 (Galatrella Valley, clay soil) showed the highest inhibition of linoleic acid oxidation with more efficacy than propyl gallate, the reference drug.

Characterisation of the essential oil of Nepeta glomerata Montbret et Aucher ex Bentham from Lebanon and its biological activities.

The essential oil of Nepeta glomerata from Lebanon was studied by means of GC and GC/MS analysis; 70 compounds were identified. The oil was constituted mainly by monoterpenes and the most abundant components were α-pinene, spathulenol and carvacrol. Nepeta glomerata oil showed antibacterial activity, particularly towards Gram-positive bacteria, and also inhibited LPS-induced NO production in macrophage cell line RAW 264.7, with an IC(50) value of 78.1 µg mL(-1). Furthermore, an in vitro cytotoxic assay showed that the oil was more active on a renal adenocarcinoma cell line (48% of inhibition of proliferation at 100 µg mL(-1)) in comparison to an amelanotic melanoma.

Chemical composition, antioxidant properties and anti-cholinesterase activity of Cordia gilletii (Boraginaceae) leaves essential oil.

This study aimed to investigate for the first time the chemical composition, the antioxidant properties and the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity of the essential oil from the leaves of Cordia gilletii De Wild (Boraginaceae). The essential oil, characterized by 23 constituents (90.1% of the total oil), was constituted by terpene derivatives (25.6%) and non-terpene derivatives (64.5%), among which aldehydes, fatty acids and alkanes were present with the percentage of 16.5%, 18.8% and 23.1%, respectively. The antioxidant activity of C. gilletii essential oil was screened by two in vitro tests: DPPH and beta-carotene bleaching test. The essential oil revealed antioxidant activity with an IC50 value of 75.0 and 129.9 microg/mL on DPPH radical and beta-carotene decoloration tests, respectively. Moreover, C. gilletii inhibited AChE enzyme with an IC50 value of 105.6 microg/mL.

Chemical composition and bioactivity of Citrus medica L. cv. Diamante essential oil obtained by hydrodistillation, cold-pressing and supercritical carbon dioxide extraction.

The chemical composition of the essential oil of Citrus medica L. cv. Diamante peel obtained by hydrodistillation, cold-pressing and supercritical carbon dioxide extraction techniques was determined by GC/MS analysis. Forty-six components were fully characterised. Limonene and γ-terpinene were the major components of the oils obtained by hydrodistillation (HD) and cold-pressing (CP), while citropten was the major constituent in the oil obtained by supercritical carbon dioxide extraction (SFE). Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities were evaluated. The essential oil obtained by hydrodistillation exerted the highest inhibitory activity against BChE (IC50 value of 154.6 µg mL⁻¹) and AChE (IC50 value of 171.3 µg mL⁻¹. Interestingly, the oil obtained by cold-pressing exhibited a selective inhibitory activity against AChE. The essential oils have also been evaluated for the inhibition of NO production in LPS induced RAW 264.7 macrophages. The oil obtained by hydrodistillation exerted a significant inhibition of NO production with an IC50 value of 17 µg mL⁻¹ (IC50 of positive control 53 µg mL⁻¹).

Protective effect of Hypericum calabricum Sprengel on oxidative damage and its inhibition of nitric oxide in lipopolysaccharide-stimulated RAW 264.7 macrophages.

The present study shows for the first time the phenolic composition and the in vitro properties (antioxidant and inhibition of nitric oxide production) of Hypericum calabricum Sprengel collected in Italy. The content of hypericins (hypericin and pseudohypericin), hyperforin, flavonoids (rutin, hyperoside, isoquercetrin, quercitrin, quercetin and biapigenin) and chlorogenic acid of H. calabricum, have been determined. The ethyl acetate fraction from the aerial parts of H. calabricum exhibited activity against the radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC50 value of 1.6 jig/ml. The test for inhibition of nitric oxide (NO) production was performed using the murine monocytic macrophage cell line RAW 264.7. The ethyl acetate fraction had significant activity with an IC50 value of 102 jig/ml and this might indicate that it would have an anti-inflammatory effect in vivo.