Chemical and biological variability of hot pepper fruits (Capsicum annuum var. acuminatum L.) in relation to maturity stage

The aim of the present work was to evaluate the chemical composition and the radical-scavenging and antioxidant activities of hot pepper fruits (Capsicum annuum L. var. acuminatum) at three maturity stages (small green, green and red). GC–MS analysis of n-hexane and chloroform fractions showed a different composition between the three stages of ripening. The first stage of maturation (small green) showed the highest radical-scavenging activity (IC₅₀ of 129 μg/ml). Using the bovine brain peroxidation assay, the methanolic extract of green pepper showed significant antioxidant activity (IC₅₀ of 522 μg/ml). Addition of methanolic extract of red and green pepper inhibited oxidation of linoleic acid. Methanolic extract of red pepper showed greater antioxidative potency than the others (IC₅₀ of 3 μg/ml). The different composition of lipophilic compounds and the various amount of phenolics, showed in the three stage of ripening of C. annuum var. acuminatum fruits, modifies the antioxidant activity.     

Bioactivity and chemical characterization in hydrophilic and lipophilic compounds of Chenopodium ambrosioides L.

The bioactive properties (antioxidant and antitumour activities, and hepatotoxicity) of the infusion and methanolic extracts of Chenopodium ambrosioides L., a plant commonly used in Portuguese folk medicine, were compared. The chemical composition in hydrophilic (sugars, organic acids and phenolic compounds) and lipophilic (fatty acids and tocopherols) fractions were determined. In general, the infusion revealed higher antioxidant activity, while the methanolic extract was the only one showing antitumour effects against colon, cervical and hepatocellular carcinoma cell lines. No toxicity in non-tumour cells was observed either for the infusion or the extract. The studied plant proved to be a good source of natural antioxidants and other bioactive compounds, which may have industrial use. As far as we know, this is the first detailed chemical characterization and bioactivity evaluation of C. ambrosioides methanolic extract and infusion.     

Anti-complementary activity of flavonoids from Gnaphalium affine D. Don

Gnaphalium affine D. Don, is used as a vegetable as well as a folk medicine in China for its anti-inflammatory, antitussive, and expectorant activities. Phytochemical investigation of the ethyl acetate (EtOAc) fraction of this plant led to isolation of three new acylated flavonol glycosides, apigenin 4′-O-β-d-(6″-E-caffeoyl)-glucopyranoside, luteolin 4′-O-β-d-(6″-E-caffeoyl)-glucopyranoside, and quercetin 4′-O-β-d-(6″-E-caffeoyl)-glucopyranoside, together with 24 known compounds. The structures of these compounds were determined by spectroscopic methods. All compounds were evaluated for their anti-complementary activity on the classical pathway of the complement system in vitro, and luteolin 4′-O-β-d-(6″-E-caffeoyl)-glucopyranoside exhibited highest anti-complementary activity with an IC₅₀ value of 0.045 ± 0.005 mg/ml. This is the first report of anti-complementary activity of G. affine D. Don, which displays the initial evidence that this plant is a potent complement inhibitor.     

Chemical composition and biological activity of Citrus jambhiri Lush

The fresh peel of Citrus jambhiri was extracted with aqueous methanol and the residue was fractionated using light petroleum, chloroform and ethyl acetate. The constituents of the extracts were separated by column chromatography employing solvents of different polarity. The chemical structure of the isolated compounds was then identified by MS and NMR. Column chromatography of the petroleum fraction resulted in the isolation of nobiletin, 5-O-demethylnobiletin, tangeretin, 5-hydroxy-3,6,7,8,3′,4′-hexamethoxyflavone, 3,5,6,7,8,3′,4′-heptamethoxyflavone, and a mixture of β-sitosterol and stigmasterol. The chloroform fraction afforded 6-demethoxynobiletin, 5,4′-dihydroxy-6,7,8,3′-tetramethoxyflavone, limonin and nomilin. The flavonoid glycosides naringin, hesperidin and neohesperidin were isolated from the ethyl acetate fraction. The chemical structure of the isolated compounds was established by MS and NMR (APT, COSY, HSQC, HMBC, and NOESY). LC–ESI-MS analysis of the ethyl acetate fraction afforded eight flavonoid glycosides, while the dichloromethane fraction of the defatted seeds contained seven limonoid aglycones. The chloroform fraction exerted the strongest DPPH^∗ free radical scavenging activity in comparison to other fractions. The petroleum fraction showed a significant inhibition of lipoxygenase indicating an anti-inflammatory action (IC₅₀ 29 ± 1 μg/mL). Some of the isolated polymethoxyflavones exhibited strong cytotoxicity against COS7, HeLa and Caco-2 cell lines.     

Nutrients,phytochemicals and bioactivity of wild Roman chamomile: A comparison between the herb and its preparations

Roman chamomile, Chamaemelum nobile L. (Asteraceae), has been used for medicinal applications, mainly through oral dosage forms (decoctions and infusions). Herein, the nutritional characterisation of C. nobile was performed, and herbal material and its decoction and infusion were submitted to an analysis of phytochemicals and bioactivity evaluation. The antioxidant activity was determined by free radicals scavenging activity, reducing power and inhibition of lipid peroxidation, the antitumour potential was tested in human tumour cell lines (breast, lung, colon, cervical and hepatocellular carcinomas), and the hepatotoxicity was evaluated using a porcine liver primary cell culture. C. nobile proved to be an equilibrated valuable herb rich in carbohydrates and proteins, and poor in fat, providing tocopherols, carotenoids and essential fatty acids (C18:2n6 and C18:3n3). Moreover, the herb and its infusion are a source of phenolic compounds (flavonoids such as flavonols and flavones, phenolic acids and derivatives) and organic acids (oxalic, quinic, malic, citric and fumaric acids) that showed antioxidant and antitumour activities, without hepatotoxicity. The most abundant compounds in the plant extract and infusion were 5-O-caffeoylquinic acid and an apigenin derivative. These, as well as other bioactive compounds, are affected in C. nobile decoction, leading to a lower antioxidant potential and absence of antitumour potential. The plant bioactivity could be explored in the medicine, food, and cosmetic industries.     

Immunomodulatory and anticancer activities of phenolics from emblica fruit (Phyllanthus emblica L.)

There is a paucity of studies on the immunomodulatory properties of fruit extracts of emblica with the emphasis on lymphocytes. Therefore, the aim of the study was to evaluate the immunomodulatory properties and anticancer potential of six phenolic compounds from emblica fruit by in vitro proliferation assay. Effects of these compounds on splenocyte proliferation and the cytotoxicity to both human breast cancer cell (MCF-7) and human embryonic lung fibroblast cell (HELF) were determined by the MTT method. Significantly stimulatory effects (P < 0.05) were found for geraniin and isocorilagin. The concentration of geraniin, quercetin 3-β-d-glucopyranoside, kaempferol 3-β-d-glucopyranoside, isocorilagin, quercetin, kaempferol and rutin to obtain 50% of stimulatory effect was 56, 123, 242, 42, 73, 93 and 92 μg/ml, respectively. The assay of anticancer activities suggested that geraniin and isocorilagin exhibited higher cytotoxicities than other compounds against MCF-7 with IC₅₀ of 13.2 and 80.9 μg/ml, respectively. Isocorilagin exhibited a strong cytotoxicity to HELF cell with IC₅₀ of 51.4 μg/ml. Geraniin, quercetin, kaempferol and their glycosides had weak cytotoxicity against HELF cells. Paclitaxel showed a strong cytotoxicity to MCF-7 and HELF with IC₅₀ of 6.8 and 14.5 μg/ml, respectively. These findings are in line with the reported potent antioxidant activity. These results suggested that the antitumour activity of these compounds might be achieved by immunomodulatory properties which could partially be attributed to their antioxidant activity.     

Chemical composition and antioxidant activity of the essential oil of Clinopodium vulgare L.

This study was designed to examine the chemical composition and in vitro antioxidant activity of the essential oil of Clinopodium vulgare. GC–MS analysis of the oil resulted in the identification of 40 compounds, representing 99.4% of the oil; thymol (38.9%), γ-terpinene (29.6%) and p-cymene (9.1%) were the main components. The samples were subjected to a screening for their possible antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene-linoleic acid assays. In the first case, IC₅₀ value of the C. vulgare essential oil was determined as 63.0 ± 2.71 μg/ml. IC₅₀ value of thymol and γ-terpinene, the major compounds of the oil, was determined as 161 ± 1.3 μg/ml and 122 ± 2.5 μg/ml, respectively, whereas p-cymene did not show antioxidant activity. In β-carotene-linoleic acid system, C. vulgare essential oil exhibited 52.3 ± 1.19% inhibition against linoleic acid oxidation. In both systems, antioxidant capacities of BHT, curcumine and ascorbic acid were also determined in parallel experiments.     

Antioxidant and anti-inflammatory properties of taiwanese yam (Dioscorea japonica Thunb. var. pseudojaponica (Hayata) Yamam.) and its reference compounds

Dioscorea japonica Thunb. var. pseudojaponica (DP) is consumed as food and widely used in traditional Chinese medicine in Taiwan. The aims of this study are to investigate the antioxidant and anti-inflammatory effects of ethanol extract of DP (EDP) and its reference compounds. Fingerprint chromatogram from HPLC indicated that EDP contains gallic acid and vanillic acid. EDP was evaluated for its antioxidant effects and LPS-induced nitrite oxide (NO) production in RAW264.7 cells. EDP decreased the LPS-induced NO production and expressions of iNOS and COX-2 in RAW264.7 cells. In-vivo anti-inflammatory activities of EDP were assessed in mouse paw oedema induced by λ-carrageenan (Carr). We investigated the antioxidant mechanism of EDP via studies of the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) and the levels of malondialdehyde (MDA) in the oedematous paw. The results showed that EDP might be a natural antioxidant and anti-inflammatory agent.     

Inhibitory effect of sour orange (Citrus aurantium) juice on Salmonella Typhimurium and Listeria monocytogenes

The sour orange (Citrus aurantium) juice is commonly used as flavoring and acidifying agent for vegetable salads and appetizers in Turkey. It was aimed to determine the survival and growth pattern of Salmonella Typhimurium and Listeria monocytogenes in sour orange juice. Different concentrations of neutralized and un-neutralized juice samples were inoculated with each of the test microorganisms (∼6 log CFU/mL) separately and then incubated at 4 °C and 37 °C for seven days. It was detected both of the test microorganisms could survive and even grow in neutralized juice samples at 37 °C for two days. However, none of them could survive at the end of seventh day of incubation at 37 °C. Low incubation temperature (+4 °C) increased the survival of the tested microorganisms. Also, it was detected that L. monocytogenes were less resistant to the variable conditions than S. Typhimurium. It was concluded that the antimicrobial effect of sour orange juice mainly depends on the low pH value of the product. However, incubation time and temperature are also effective on the survival of the tested pathogens.     

A new flavone from antioxidant extracts of Pistacia terebinthus

Acetone and methanol extracts of the fruits of Pistacia terebinthus L. subsp. terebinthus L. were studied for their antioxidant activity by investigating their total phenolic and flavonoid contents, β-carotene bleaching potential, DPPH radical scavenging effect, scavenging activity on superoxide anion radical, reducing power, and metal chelating effect on ferrous ion. Both extracts showed very similar chemical profile by checking on TLC plates, and exhibited high scavenging activity on superoxide anion radical and DPPH radical. Due to these similarities they were combined and fractionated on a silica gel column for their constituents, and the most active three fractions in DPPH assay were purified to afford a new flavone 6′-hydroxyhypolaetin 3′-methyl ether (1) besides a group of known flavonoids apigenin, luteolin, luteolin 7-O-glucoside, quercetin, quercetagetin 3-methyl ether 7-O-glucoside, isoscutellarein 8-O-glucoside. Their structures were established by UV, UV shift reagents, and ¹H NMR spectroscopic techniques. Antioxidant activity of the new flavone was investigated by β-carotene bleaching and DPPH radical scavenging activity methods, and it showed a high activity in the first system, but not so good in the latter.     

Rosmarinic acid,scutellarein 4′-methyl ether 7-O-glucuronide and (16S)-coleon E are the main compounds responsible for the antiacetylcholinesterase and antioxidant activity in herbal tea of Plectranthus barbatus (“falso boldo”)

Plectranthus barbatus, known as “falso boldo” in Brazil, is used in herbal tea or cooked as a vegetable. Infusions and decoctions of leaves from P. barbatus were analysed for their inhibition of acetylcholinesterase and their antioxidant activity. The decoction showed high inhibition activity (31% inhibition with 0.5 mg of extract/ml) and also high antioxidant activity (IC₅₀ = 45.8 ± 0.5 μg of dry extract/ml in the DPPH test; IC₅₀ = 69.8 ± 3.1 μg of dry extract/ml in the β-carotene–linoleic acid test). Rosmarinic acid, scutellarein 4′-methyl ether 7-O-glucuronide and (16S)-coleon E were the main constituents identified. These compounds have antiacetylcholinesterase activity. Rosmarinic acid and the scutellarein derivative have IC₅₀ = 440 μg/ml and 1 mg/ml, respectively. One milligram per millilitre of (16S)-coleon E showed 61% inhibition of the enzyme. Other Plectranthus species, P. ecklonii, P. fructicosus, P. lanuginosus and P. verticillatus, were also analysed and the results obtained correlated with the content in rosmarinic acid.     

Chemical composition and antioxidant activity of dried powder formulations of Agaricus blazei and Lentinus edodes

Several mushroom species have been pointed out as sources of antioxidant compounds, in addition to their important nutritional value. Agaricus blazei and Lentinus edodes are among the most studied species all over the world, but those studies focused on their fruiting bodies instead of other presentations, such as powdered preparations, used as supplements. In the present work the chemical composition (nutrients and bioactive compounds) and antioxidant activity (free radical scavenging activity, reducing power and lipid peroxidation inhibition) of dried powder formulations of the mentioned mushroom species (APF and LPF, respectively) were evaluated. Powder formulations of both species revealed the presence of essential nutrients, such as proteins, carbohydrates and unsaturated fatty acids. Furthermore, they present a low fat content (<2 g/100 g) and can be used in low-calorie diets, just like the mushrooms fruiting bodies. APF showed higher antioxidant activity and higher content of tocopherols and phenolic compounds (124 and 770 μg/100 g, respectively) than LPF (32 and 690 μg/100 g). Both formulations could be used as antioxidant sources to prevent diseases related to oxidative stress.     

Effects of binary solvent extraction system,extraction time and extraction temperature on phenolic antioxidants and antioxidant capacity from mengkudu (Morinda citrifolia)

An investigation into the effects of ethanol concentration (0–100%, v/v), extraction time (20–120 min) and extraction temperature (25–65 °C) on the extraction of phenolic antioxidants from mengkudu (Morinda citrifolia) was performed using a single-factor experiment. Total phenolic content (TPC) and total flavonoid content (TFC) assays were used for determination of phenolic compounds. Antioxidant capacity was evaluated by measuring the scavenging effect on 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radicals. Experimental results showed that extraction conditions had significant effect on extraction of phenolic compounds and antioxidant capacities. The optimised conditions were 40% ethanol for 80 min at 65 °C, with values of 919.95 mg GAE/100 g DW for TPC, 472.73 mg CE/100 g DW for TFC, 791.71 μmol TEAC/100 g DW for ABTS and 1928.5 μmol TEAC/100 g DW for DPPH. TPC was significantly correlated with DPPH under the effects of ethanol concentration (r = 0.932) and extraction time (r = −0.938).     

Constituents of Sideritis syriaca. ssp. syriaca (Lamiaceae) and their antioxidant activity

The aerial parts of Sideritis syriaca ssp. syriaca (Lamiaceae) were extracted, after defatting, with diethyl ether, ethyl acetate and n-butanol. The antioxidant activities of the extracts were evaluated through in vitro model systems, such as 1,1-diphenyl-2-picryl hydrazyl (DPPH) and Co(II) EDTA-induced luminol chemiluminescence. In both model systems the ethyl acetate extract was the most effective. Phytochemical analysis of ethyl acetate extract showed the presence of two new isomeric compounds (1 and 1′), identified as 1-rhamnosyl, 1-coumaroyl, dihydrocaffeoyl, protocatechuic tetraester of quinic acid, as well as chlorogenic acid (2), apigenin 7-O-glucoside (3), apigenin (4), 4′-O-methylisoscutellarein 7-O-[6′′′-O-acetyl-β-D-allopyranosyl-(1 → 2)-β-d-glucopyranoside] (5), isoscutellarein 7-O-[6′′′-O-acetyl-β-D-allopyranosyl-(1 → 2)-β-d-glucopyranoside] (6), 4′-O-methylisoscutellarein 7-O[β-d-allopyranosyl-(1 → 2)-β-d-glucopyranoside] (7) and 4′-O-methylisoscutellarein 7-O-[β-d-allopyranosyl-(1 → 2)-6′′-O-acetyl-β-d-glucopyranoside] (8). The above compounds were identified by spectroscopic methods.     

Infusion and decoction of wild German chamomile: Bioactivity and characterization of organic acids and phenolic compounds

Natural products represent a rich source of biologically active compounds and are an example of molecular diversity, with recognised potential in drug discovery. Herein, the methanol extract of Matricaria recutita L. (German chamomile) and its decoction and infusion (the most consumed preparations of this herb) were submitted to an analysis of phytochemicals and bioactivity evaluation. The antioxidant activity was determined by free radicals scavenging activity, reducing power and inhibition of lipid peroxidation; the antitumour potential was tested in human tumour cell lines (breast, lung, colon, cervical and hepatocellular carcinomas), and the hepatotoxicity was evaluated using a porcine liver primary cell culture (non-tumour cells). All the samples revealed antioxidant properties. The decoction exhibited no antitumour activity (GI₅₀ > 400 μg/mL) which could indicate that this bioactivity might be related to compounds (including phenolic compounds) that were not extracted or that were affected by the decoction procedure. Both plant methanol extract and infusion showed inhibitory activity to the growth of HCT-15 (GI₅₀ 250.24 and 298.23 μg/mL, respectively) and HeLa (GI₅₀ 259.36 and 277.67 μg/mL, respectively) cell lines, without hepatotoxicity (GI₅₀ > 400 μg/mL). Infusion and decoction gave higher contents of organic acids (24.42 and 23.35 g/100 g dw). Otherwise, the plant methanol extract contained the highest amounts of both phenolic acids (3.99 g/100 g dw) and flavonoids (2.59 g/100 g dw). The major compound found in all the preparations was luteolin O-acylhexoside. Overall, German chamomile contains important phytochemicals with bioactive properties (mainly antitumour potential selective to colon and cervical carcinoma cell lines) to be explored in the pharmaceutical, food and cosmetics industries.     

玳玳花精油的成分及其抗氧化活性研究

以玳玳花精油为试验材料,利用气相色谱-质谱联用技术对其进行组分分析,测定了其理化特征,采用DPPH、ABTS、羟基自由基的清除率及总抗氧化能力来评价其抗氧化活性。结果表明,玳玳花精油是一种具有玳玳花特征香气的琥珀色澄清液体,共分离出41种成分,占总成分95.80%,其中包括13种醇类化合物(59.34%),16种萜烯类化合物(22.82%),4种烷烃类化合物、3种酸、3种酯类、1种吲哚和1种酚类化合物。玳玳花精油的总抗氧化能力在4 mg/mL时超过VC;对DPPH自由基清除能力较弱,精油浓度为50 mg/mL时清除率为73.51%;对ABTS和羟基自由基清除能力较好,10mg/mL时清除率分别达到85.63%和94.87%;综上,玳玳花精油具有显著的抗氧化作用且与浓度呈正相关。     

Antioxidant activities of compounds isolated from Dalbergia odorifera T. Chen and their inhibition effects on the decrease of glutathione level of rat lens induced by UV irradiation

Four compounds were isolated from the root of Dalbergia odorifera T. Chen and identified by chemical and spectroscopic methods as 2′-O-methyl-isoliquiritigenin (1), odoriflavene (2), 5′-methoxy-vestitol (3) and formononetin (4). Their antioxidant activities were investigated in lard by the oxidative stability instrument; their inhibitory effects on the decrease of glutathione level of rat lens induced by UV irradiation were studied using a rat lens UV-damage model, and their in vitro cytotoxicity was measured on human SH-SY5Y neuroblastoma cells. Results indicated that all four compounds had obvious antioxidant effects, while none of them showed any synergistic effects on butylated hydroxytoluene or α-tocopherol. When FeCl₃ (4.0 μM) was added, the antioxidant activities of the four compounds markedly decreased. The inhibitory effects of compounds 1, 2 and 4 on the decrease of glutathione level of rat lens induced by UV irradiation were comparable to that of α-tocopherol. All four compounds showed cytotoxic activity when evaluated against a SH-SY5Y cell line in vitro.     

The antioxidant and free-radical scavenging activities of extract and fractions from corn silk (Zea mays L.) and related flavone glycosides

This study was designed to evaluate both the antioxidant and free-radical scavenging activities of extract and fractions from corn silk. N-butanol fraction (BF) demonstrated the highest total phenolic content (164.1 ± 9.7 μg GAE/g DCS) and total flavonoids content (69.4 ± 5.1 μg RE/g DCS), accompanied with the highest antioxidant activity compared to other fractions through all antioxidant assays. Two flavone glycosides showing potent antioxidant activity were isolated from BF and identified, by comparing spectral data (UV, FAB-MS and NMR) with literature values, to be isoorientin-2″-O-α-l-rhamnoside and 3′-methoxymaysin. The two isolated flavone glycosides, particularly isoorientin-2″-O-α-l-rhamnoside, demonstrated significant total antioxidant activity, DPPH radical scavenging activity, reducing power and iron-chelating capacity, with EC₅₀ values of 14.24 ± 1.49, 22.69 ± 2.33, 6.58 ± 1.07 and 30.25 ± 3.05 μg/ml, respectively. Results obtained indicated that corn silk extracts can be used potentially as a ready accessible and valuable bioactive source of natural antioxidants.     

New coumarins and anti-inflammatory constituents from Zanthoxylum avicennae

Zanthoxylum avicennae is commercially used as healthcare products for the improvement of chronic hepatitis and rheumatism. Its fruit is also used as a spice. Five new coumarins, 5′-methoxyauraptene (1), 6,5′-dimethoxyauraptene (2), 5′-methoxycollinin (3), 7-((2′E,5′E)-7′-methoxy-3′,7′-dimethylocta-2′,5′-dienyloxy)coumarin (4), and 6-methoxy-7-((2′E,5′E)-7′-methoxy-3′,7′-dimethylocta-2′,5′-dienyloxy)coumarin (5), have been isolated from the leaves of Z. avicennae, together with 15 known compounds (6–20). The structures of these new compounds were determined through spectroscopic and MS analyses. Compounds 6, 9–15, and 18 exhibited inhibition (IC₅₀ ? 8.29 μg/ml) of superoxide anion generation by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (fMLP/CB). Compounds 6, 10, 12, 14, and 18 inhibited fMLP/CB-induced elastase release with IC₅₀ values ?6.30 μg/ml.