Efficacy of various naturally occurring caffeic acid derivatives in preventing post-harvest protein losses in forages

BACKGROUND

In red clover, oxidation of endogenous o-diphenols by polyphenol oxidase (PPO) inhibits post-harvest proteolyis. This system is transferable to alfalfa by providing PPO (via a transgene) and o-diphenol PPO substrates (via exogenous application). To exploit the PPO system for protein protection, it would be advantageous to produce PPO substrates in alfalfa, which lacks them. We assessed the extent of PPO-mediated proteolytic inhibition by phenolic compounds, especially those whose biosynthesis could be engineered into alfalfa.

RESULTS

Tested compounds included o-diphenols (caffeic acid, phaselic acid, chlorogenic acid, clovamide) and monophenols (p-coumaric acid, p-coumaroyl-malic acid). In the presence of PPO, 2 mmol o-diphenol g⁻¹ protein reduced 24 h proteolysis 68-87% (P < 0.001) and as little as 0.25 mmol g⁻¹ protein still decreased 24 h proteolysis 43-60% (P < 0.001). At high concentrations, clovamide inhibited 24 h proteolysis 50% (P < 0.001) in the absence of PPO, likely due to non-PPO oxidation. Monophenol p-coumaric acid did not inhibit 24 h proteolyis, although high levels of its malate ester did exhibit PPO- and oxygen-independent inhibition (37%, P < 0.001).

CONCLUSIONS

For PPO-mediated proteolytic inhibition, pathways for both phaselic acid and chlorogenic acid may be good targets for engineering into alfalfa. Clovamide may be useful for inhibiting proteolysis without PPO.

NaStEP: a proteinase inhibitor essential to self-incompatibility and a positive regulator of HT-B stability in Nicotiana alata pollen tubes

In Solanaceae, the self-incompatibility S-RNase and S-locus F-box interactions define self-pollen recognition and rejection in an S-specific manner. This interaction triggers a cascade of events involving other gene products unlinked to the S-locus that are crucial to the self-incompatibility response. To date, two essential pistil-modifier genes, 120K and High Top-Band (HT-B), have been identified in Nicotiana species. However, biochemistry and genetics indicate that additional modifier genes are required. We recently reported a Kunitz-type proteinase inhibitor, named NaStEP (for Nicotiana alata Stigma-Expressed Protein), that is highly expressed in the stigmas of self-incompatible Nicotiana species. Here, we report the proteinase inhibitor activity of NaStEP. NaStEP is taken up by both compatible and incompatible pollen tubes, but its suppression in Nicotiana spp. transgenic plants disrupts S-specific pollen rejection; therefore, NaStEP is a novel pistil-modifier gene. Furthermore, HT-B levels within the pollen tubes are reduced when NaStEP-suppressed pistils are pollinated with either compatible or incompatible pollen. In wild-type self-incompatible N. alata, in contrast, HT-B degradation occurs preferentially in compatible pollinations. Taken together, these data show that the presence of NaStEP is required for the stability of HT-B inside pollen tubes during the rejection response, but the underlying mechanism is currently unknown.

A sensitive and selective liquid chromatography-tandem mass spectrometry method for simultaneous determination of five isoquinoline alkaloids from Chelidonium majus L. in rat plasma and its application to a pharmacokinetic study

Chelidonium majus L. is one of the most important medicinal plants of the family Papaveraceae. Its pharmacological effects have been primarily attributed to the presence of a number of alkaloids. In the present study, a sensitive and selective liquid chromatography-tandem mass spectrometry method for simultaneous determination of five isoquinoline alkaloids from Chelidonium majus L. was developed and validated. The analytes (protopine, chelidonine, coptisine, sanguinarine and chelerythrine), together with the internal standard (palmatine), were extracted from acidified rat plasma with ethyl acetate-dichloromethane (4:1, v/v). Chromatographic separation was carried out on a Diamonsil C(18) column with an isocratic mobile phase consisting of acetonitrile and water (adjusted to pH 2.3 with formic acid) (30:70, v/v) at a flow rate of 0.4 ml/min. Mass spectrometric detection was performed by selected reaction monitoring mode via electrospray ionization source operating in positive ionization mode. The assay exhibited good linearity (r ≥ 0.9933) for all the analytes. The lower limits of quantification were 0.197-1.27 ng/ml using only 50 µl of plasma sample. The intra- and inter-day precisions were less than 11.9%, and the accuracy was between -6.3% and 9.3%. The method was successfully applied to the pharmacokinetic study of the five alkaloids in rats after intragastric administration of Chelidonium majus L. extract.

Antioxidant and antimicrobial properties of monofloral bee pollen

The main aim of this study was to determine antioxidant properties and antibacterial activity of monofloral bee pollen samples to pathogenic bacteria. These samples were collected in different localities in Slovakia. The antioxidant properties of examined plant species were different and decreasing in the following order: Brassica napus subsp. napus L > Papaver somniferum L. > Helianthus annuus L. The antimicrobial effect of the bee product samples were tested by using the agar well diffusion method. The methanol (99.9% and 70%) and the ethanol (96% and 70%) were used for extraction. In this study, five different strains of bacteria were tested: Listeria monocytogenes CCM 4699; Pseudomonas aeruginosa CCM 1960; Staphylococcus aureus CCM 3953; Salmonella enterica CCM 4420; and Escherichia coli CCM 3988. The most sensitive bacteria of the poppy pollen ethanolic extract was Staphylococcus aureus was (70%) The most sensitive bacteria of rape bee pollen methanolic extract (70%) and sunflower ethanolic extract (70%) was Salmonella enterica.

Biogas production from wheat straw in batch and UASB reactors: the roles of pretreatment and seaweed hydrolysate as a co-substrate

This research evaluated biogas production in batch and UASB reactors from pilot-scale acid catalysed steam pretreated and enzymatic hydrolysed wheat straw. The results showed that the pretreatment was efficient and, a sugar yield of 95% was obtained. The pretreatment improved the methane yield (0.28 m(3)/kg VS(added)) by 57% compared to untreated straw. Treatment of the straw hydrolysate with nutrient supplementation in a UASB reactor resulted in a high methane production rate, 2.70 m(3)/m(3).d at a sustainable OLR of 10.4 kg COD/m(3).d and with a COD reduction of 94%. Alternatively, co-digestion of the straw and seaweed hydrolysates in a UASB reactor also maintained a stable anaerobic process and can thus reduce the cost of nutrients addition. We have shown that biogas production from wheat straw can be competitive by pretreatment, high methane production rate in UASB reactors and also by co-digestion with seaweed hydrolysate.

Evaluation of the mutagenicity and genotoxicity of Arrabidaea chica Verlot (Bignoneaceae), an Amazon plant with medicinal properties

Arrabidaea chica Verlot (Bignoniaceae) is an important folk medicine plant native to the Amazon region and used to treat anemia, hemorrhage, inflammation, intestinal colic, hepatitis, and skin affections. Although studies showed its therapeutic properties, little knowledge regarding genotoxic properties of this plant is available. The aim of this study was to determine the potential mutagenic and genotoxic/antigenotoxic effects of an A. chica chloroformic fraction (Ac-CF) obtained from leaves containing bioactive metabolites. The mutagenic effects were evaluated using the Salmonella mutagenicity assay, with TA98, TA97a, TA100, TA102, and TA1535 strains, with and without metabolic activation. In vivo mutagenic and genotoxic/antigenotoxic effects were investigated using the micronucleus (MN) test in bone marrow and alkaline comet assay in blood and liver after administration of 100, 500, or 1000 mg/kg Ac-CF in CF-1 mice by gavage (once a day for 3 d). In vitro antioxidant potential was evaluated using DPPH and xanthine/hypoxanthine assays. Ac-CF was not mutagenic in any of the Salmonella typhimurium strains tested and showed negative responses for mutagenicity and genotoxicity in mice. Further, Ac-CF displayed antigenotoxic effects by decreasing the oxidative DNA damage induced by hydrogen peroxide by greater than 50% in blood and liver. The antioxidant action detected in the in vitro assays demonstrated IC50 of 0.838 mg/ml in the xanthine/hypoxanthine assay and IC50 of 28.17 μg/ml in the DPPH assay. In conclusion, Ac-CF did not induce mutagenic and genotoxic effects and was able to protect DNA against oxidative damage in vivo, suggesting that this fraction may not pose genetic risks, although further toxicology assays are necessary.

Assessment of the effect of condensed (acacia and quebracho) and hydrolysable (chestnut and valonea) tannins on rumen fermentation and methane production in vitro

BACKGROUND

Tannins added to animal diets may have a positive effect on energy and protein utilisation in the rumen. The objective of this study was to examine the impact of different sources and concentrations (20, 50, 100, 150 and 200 g kg⁻¹ dry matter (DM)) of condensed (acacia and quebracho) and hydrolysable (chestnut and valonea) tannins on rumen microbial fermentation in vitro. The experiment also included a negative control with no tannins (control) and a positive control with monensin (10 mg L⁻¹).

RESULTS

In vitro gas production and total volatile fatty acid (VFA) concentration decreased as tannin concentration increased. Addition of acacia, chestnut or valonea tannins at ≥ 50 g kg⁻¹ or quebracho tannins at ≥ 100 g kg⁻¹ resulted in a decrease (up to 40%) in methane (CH₄) production compared with the control. Valonea tannins were the only tannin source that reduced (-11%) CH₄ production at 50 g kg⁻¹ without affecting VFA concentration. Tannin treatments reduced ammonia (NH₃) and branched-chain VFA concentrations, indicating a reduction in ruminal protein degradation. Monensin reduced CH₄ production (-37%) and NH₃ concentration (-20%) without affecting total VFA concentration.

CONCLUSION

Supplying acacia, chestnut or valonea tannins at 50 g kg⁻¹ has the potential to reduce CH₄ production and ruminal protein degradation with minimum detrimental effects on efficiency of ruminal fermentation.

Comparative study of bioactive constituents in crude and processed Glycyrrhizae radix and their respective metabolic profiles in gastrointestinal tract in vitro by HPLC-DAD and HPLC-ESI/MS analyses

Two HPLC methods with diode array detection (HPLC-DAD) and electrospray ionization-mass spectrometry (HPLC-ESI/MS), respectively, were developed to investigate the differences of chemical constituents and their metabolism in gastrointestinal tract in vitro between two decoctions of crude and processed Glycyrrhizae radix. Total of eleven constituents (liquiritin apioside, liquiritin, licuraside, isoliquiritin, ononin, glycyrrhizin, liquiritigenin-7,4'-diglucoside, licorice saponin A3, 22β-acetoxylglycyrrhizic acid, licorice saponin G2, and yunganoside E2) were identified in the two decoctions, whereas lower contents of these constituents were usually found in the decoction of processed Glycyrrhizae Radix. [corrected] Furthermore, these constituents were metabolized into their respective aglycons in human intestinal bacteria juice, and the metabolism ratios were all higher in processed Glycyrrhizae Radix [corrected] decoction. No change was found in artificial gastric or intestinal juice. This study revealed that the processing can alter the contents of main constituents in crude G. radix and their metabolism in gastrointestinal tract, in which intestinal bacteria play an important role in the metabolism of licorice constituents.

Antidiabetic effect of kolaviron, a biflavonoid complex isolated from Garcinia kola seeds, in Wistar rats

BACKGROUND

Hypoglycaemic effect of kolaviron (KV), (biflavonoid from Garcinia kola) in streptozotocin (STZ)-diabetic rats has been established.

OBJECTIVES

To evaluate the possible protective effects of KV on cardiac, renal and hepatic tissues of STZ-diabetic rats.

METHODS

This study consists of four groups of 6 rats each. Groups one and two contained non-diabetic and untreated-diabetic rats, respectively. Groups three and four were made up of KV- and glibenclamide (GB) - treated diabetic rats, respectively.

RESULTS

STZ-intoxication caused a significant (p<0.05) increase in the relative weight of liver in diabetic rats. STZ-diabetic rats had significant increase (p<0.05) in the levels of fasting blood glucose (FBG), á-amylase and HbA1c. A marked and significant (p<0.05) increase in the levels of cardiac, renal and liver marker indices such as serum creatine kinase, lactate dehydrogenase, creatinine, urea and alanine aminotransferase were observed in untreated diabetic rats. Also, untreated diabetic rats had significantly (p<0.05) elevated urinary glucose and protein and, lowered creatinine clearance. In KV- and GB- treated groups, the levels of FBG, á-amylase and HbA1c were significantly (p<0.05) reduced, while treatment with KV significantly (p<0.05) attenuated the cardiac, renal and liver marker indices.

CONCLUSION

KV offered significant antidiabetic and tissues protective effects in the rats.

Efficient ethanol production from separated parenchyma and vascular bundle of oil palm trunk

For efficient utilization of both starchy and cellulosic materials, oil palm trunk was separated into parenchyma (PA) and vascular bundle (VB). High solid-state simultaneous saccharification and fermentation (HSS-SSF) using 30% (w/v) PA, containing 46.7% (w/w) starch, supplemented with amylases and Saccharomyces cerevisiae K3, produced 6.1% (w/v) ethanol. Subsequent alkali-pretreatment using sodium hydroxide was carried out with starch-free PA (sfPA) and VB. Enzymatic digestibility of 5% (w/v) pretreated sfPA and VB was 92% and 97%, respectively, using 18 FPU of commercial cellulase supplemented with 10 U of Novozyme-188 per gram of substrate. Likewise, HSS-SSF using 30% (w/v) alkali-pretreated sfPA and VB, with cellulases and yeast, resulted in high ethanol production (8.2% and 8.5% (w/v), respectively). These results show that HSS-SSF using separated PA and VB is a useful fermentation strategy, without loss of starchy and cellulosic materials, for oil palm trunk.

Apoptotic effects of cooked and in vitro digested soy on human prostate cancer cells

Previous laboratory and animal studies reported that soy isoflavones were major bioactive compounds in soy to exert chemoprotection of prostate cancer. However, these studies cannot reflect the realistic effects that soy may induce through diets, and little is known about the bioavailability of isoflavones from whole soy food and their bioactivities after cooking and digestion. In this study, cooking and in vitro digestion were used to prepare soy extracts and the effects of cooking and digestion on the isoflavone contents and bioactivities of the whole soy extracts were examined. The cooking procedure generally increased the amount of daidzin, genistin and daidzein, but decreased that of genistein. Digestion process significantly lowered contents of daidzin and genistin in 60min cooked sample, while increased the contents of daidzin and daidzein and decreased the content of genistein in the uncooked sample. Antioxidant activities of soy extracts increased after cooking and in vitro digestion, while no consistent increase of the four soy isoflavones was determined. The apoptotic effects of soy extracts on both LNCaP and C4-2B cells were generally in a dose-dependent manner. Compared to purified single isoflavones, cooked and digested soy were more effective on induction of prostate cancer cell apoptosis, which indicated synergistic interactions between various bioactive compounds in the whole soy.

Correlation of rutin accumulation with 3-O-glucosyl transferase and phenylalanine ammonia-lyase activities during the ripening of tomato fruit

In tomato, the predominant flavonoid is quercetin-3-rutinoside (rutin). In this study, we aim to investigate the phenylalanine ammonia-lyase (PAL) and the quercetin-3-O-glucosyl transferase (3-GT) reactions in the formation of rutin during tomato fruit ripening. Tomatoes of the Moneymaker variety at different development stages (green, breaker, turning, pink, red, and deep red) were divided into flesh and peel fractions. In each sample, both the content of rutin and the enzymatic activities for PAL and 3-GT were recorded. The highest activities of PAL were recorded in the peel of turning fruit (3,000 μkat/mg fresh weight). In fruit flesh, maximal activity was observed in red fruit (917.3 μkat/mg). For both tissues, PAL activity strongly decreased at the final (deep red) fruit stage. The activity of 3-GT in peel peaked in the turning fruit stage (50.7 pkat/mg), while in flesh maximal activity (33.4 pkat/mg) was observed in green fruit, which rapidly declined at the turning stage. Higher levels of rutin were detected in the tomato peel compared to the flesh part with the highest level being found at the green stage. The relation of PAL and 3-GT activities to rutin content is also evaluated.

Overexpression of a Paenibacillus campinasensis xylanase in Bacillus megaterium and its applications to biobleaching of cotton stalk pulp and saccharification of recycled paper sludge

A xylanase gene (xynG1-1) from Paenibacillus campinasensis G1-1 was expressed in Bacillus megaterium MS941 and a high level of extracellular xylansae activity (304.26 IU/mL) was achieved after induction with 0.5% xylose. The purified recombinant xylanase (XynG1-1R) revealed optimal activity at 60°C and pH 7.0 and retained 79% and 81% activity after incubation without substrate at 60°C, pH 5.0 and pH 8.0 for 3h, respectively. Application of XynG1-1R (15 IU/g pulp) to cotton stalk pulp bleaching increased brightness by 3.65% over that of the control without the xylanase and reduced the need for chlorine compounds by 50% without loss of brightness and pulp fiber qualities. When XynG1-1R (80 IU/g paper sludge) was used in combination with mixed cellulolytic enzymes, the saccharification efficiency of recycled paper sludge was increased by 10%. These results indicated that XynG1-1R is a promising candidate for various industrial applications such as biobleaching and bioenergy conversion.

Polysaccharide from seeds of Plantago asiatica L. increases short-chain fatty acid production and fecal moisture along with lowering pH in mouse colon

Mice (20.0 ± 2.0 g, n = 48 per group) were given 30 days oral administration of polysaccharide from Plantago asiatica L. seeds at the dose of 0.4 g/kg body weight by gavage to investigate the effects of the polysaccharide on mouse colon. Results showed that the concentrations of total short-chain fatty acids (SCFA), acetic, propionic, and n-butyric acids in mouse colonic content of polysaccharide treated group were all significantly higher than that of control group (water) (p < 0.05). In addition, moisture of mouse colonic content of polysaccharide treated group was also notably higher than that of the control group (p < 0.05) indicating the intake of polysaccharide from P. asiatica L. resulted in a stronger water-holding capacity for colonic content throughout the experimental period. Furthermore, a decreased pH (from 7.5 ± 0.1 to 7.2 ± 0.1) was observed in mouse colon of the polysaccharide treated group compared with the control group (pH from 7.5 ± 0.1 to 7.5 ± 0.1). These results suggested that the intake of the polysaccharide from P. asiatica L. might be beneficial for the colon health.

6-gingerdiols as the major metabolites of 6-gingerol in cancer cells and in mice and their cytotoxic effects on human cancer cells

6-Gingerol, a major pungent component of ginger (Zingiber officinale Roscoe, Zingiberaceae), has been reported to have antitumor activities. However, the metabolic fate of 6-gingerol and the contribution of its metabolites to the observed activities are still unclear. In the present study, we investigated the biotransformation of 6-gingerol in different cancer cells and in mice, purified and identified the major metabolites from human lung cancer cells, and determined the effects of the major metabolites on the proliferation of human cancer cells. Our results show that 6-gingerol is extensively metabolized in H-1299 human lung cancer cells, CL-13 mouse lung cancer cells, HCT-116 and HT-29 human colon cancer cells, and in mice. The two major metabolites in H-1299 cells were purified and identified as (3R,5S)-6-gingerdiol (M1) and (3S,5S)-6-gingerdiol (M2) based on the analysis of their 1D and 2D NMR data. Both metabolites induced cytotoxicity in cancer cells after 24 h, with M1 having a comparable effect to 6-gingerol in H-1299 cells.

Mass spectrometry-based metabolite profiling and antioxidant activity of Aloe vera ( Aloe barbadensis Miller) in different growth stages

Metabolite profiling of four different-sized Aloe vera plants was performed using gas chromatography-ion trap-mass spectrometry (GC-IT-MS) and ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS) with multivariate analysis. Amino acids, sugars, and organic acids related to growth and development were identified by sizes. In particular, the relative contents of glucose, fructose, alanine, valine, and aspartic acid increased gradually as the size of the aloe increased. Anthraquinone derivatives such as 7-hydroxy-8-O-methylaloin, 7-hydroxyaloin A, and 6'-malonylnataloins A and B increased gradually, whereas chromone derivatives decreased continuously as the size of the aloe increased. The A30 aloe (size = 20-30 cm) with relatively high contents of aloins A and B, was suggested to have antioxidant components showing the highest antioxidant activity among the four different sizes of aloe. These data suggested that MS-based metabolomic approaches can illuminate metabolite changes associated with growth and development and can explain their change of antioxidant activity.

Bolus consumption of a specifically designed fruit juice rich in anthocyanins and ascorbic acid did not influence markers of antioxidative defense in healthy humans

Exotic fruits such as açai, camu-camu, and blackberries rich in natural antioxidants (ascorbic acid, anthocyanins) are marketed as "functional" foods supporting a pro-/antioxidant balance. Confirming data from human studies are lacking. Within a randomized controlled crossover trial, 12 healthy nonsmokers ingested 400 mL of a blended juice of these fruits or a sugar solution (control). Blood was drawn before and afterward to determine antioxidants in plasma, markers of antioxidant capacity [trolox equivalent antioxidant capacity, Folin-Ciocalteu reducing capacity, total oxidant scavenging capacity (TOSC)] and oxidative stress [isoprostane, DNA strand breaks in leukocytes in vivo], and their resistance versus H₂O₂-induced strand breaks. Compared with sugar solution, juice consumption increased plasma ascorbic acid and maintained TOSC and partly Folin-Ciocalteu reducing capacity (both P values < 0.05). Strand breaks in vivo increased after ingestion of both beverages (P < 0.001), probably due to postprandial and/or circadian effects. This anthocyanin-rich fruit juice may stabilize the pro-/antioxidant balance in healthy nonsmokers without affecting markers of oxidative stress.

Gut microbial metabolism of polyphenols from black tea and red wine/grape juice is source-specific and colon-region dependent

The colonic microbial degradation of a polyphenol-rich black tea extract (BTE) and red wine/grape juice extract (RWGE) was compared in a five-stage in vitro gastrointestinal model (TWINSHIME). Microbial metabolism of BTE and RWGE polyphenols in the TWINSHIME was studied subsequently in single- and continuous-dose experiments. A combination of liquid or gas chromatography with mass spectrometry (LC-MS or GC-MS) and NMR-based metabolic profiling was used to measure selected parent polyphenols, their microbial degradation into phenolic acids, and the production of short-chain fatty acids (SCFAs) in different colon compartments. Acetate production was increased by continuous feeding of BTE but not RWGE. During RWGE feeding, gallic acid and 4-hydroxyphenylpropionic acid remained elevated throughout the colon, while during BTE feeding, they were consumed in the distal colon, while 3-phenylpropionic acid was strongly produced. Gut microbial production of phenolics and SCFAs is dependent on colon location and polyphenol source, which may influence potential health benefits.

Chlorophyll catabolites in senescent leaves of the lime tree (Tilia cordata)

In cold extracts of senescent leaves of the Lime tree (Tilia cordata), two colorless nonfluorescent chlorophyll catabolites (NCCs) were identified, named Tc-NCC-1 and Tc-NCC-2, as well as a polar yellow chlorophyll catabolite (YCC), named Tc-YCC. The constitution of the two NCCs was determined by spectroscopic means. In addition, a tentative structure was derived for Tc-YCC. The three chlorophyll degradation products exhibited tetrapyrrolic structures, as are typical of NCCs or YCCs, and turned out to be rather polar, due to a glucopyranosyl group at their 8(2)-position. At their 3-positions, the more polar Tc-NCC-1 carried a 1,2-dihydroxyethyl group and the less polar Tc-NCC-2 a vinyl group. Tc-YCC was identified as the product of an oxidation of Tc-NCC-1.

Metabolome of Vanilla planifolia (Orchidaceae) and related species under Cymbidium mosaic virus (CymMV) infection

The genus Vanilla which belongs to the Orchidaceae family comprises more than 110 species of which two are commercially cultivated (Vanilla planifolia and Vanilla xtahitensis). The cured pods of these species are the source of natural vanilla flavor. In intensive cultivation systems the vines are threatened by viruses such as Cymbidium mosaic virus (CymMV). In order to investigate the effect of CymMV on the growth and metabolome of vanilla plants, four accessions grown in intensive cultivation systems under shadehouse, CR01 (V. planifolia), CR17 (V. xtahitensis), CR03 (V. planifolia × V. xtahitensis) and CR18 (Vanilla pompona), were challenged with an isolate of CymMV. CymMV infected plants of CR01, CR03 and CR17 had a reduced growth compared to healthy plants, while there was no significant difference in the growth of CR18 vines. Interestingly, CR18 had qualitatively more phenolic compounds in leaves and a virus titre that diminished over time. No differences in the metabolomic profiles of the shadehouse samples obtained by nuclear magnetic resonance (NMR) were observed between the virus infected vs. healthy plants. However, using in- vitro V. planifolia plants, the metabolomic profiles were affected by virus infection. Under these controlled conditions the levels of amino acids and sugars present in the leaves were increased in CymMV infected plants, compared to uninfected ones, whereas the levels of phenolic compounds and malic acid were decreased. The metabolism, growth and viral status of V. pompona accession CR18 contrasted from that of the other species suggesting the existence of partial resistance to CymMV in the vanilla germplasm.

Bioactive constituents in Prunus africana: geographical variation throughout Africa and associations with environmental and genetic parameters

Prunus africana--an evergreen tree found in Afromontane forests--is used in traditional medicine to cure benign prostate hyperplasia. Different bioactive constituents derived from bark extracts from 20 tree populations sampled throughout the species' natural range in Africa were studied by means of GC-MSD. The average concentration [mg/kgw/w] in increasing order was: lauric acid (18), myristic acid (22), n-docosanol (25), ferulic acid (49), β-sitostenone (198), β-sitosterol (490), and ursolic acid (743). The concentrations of many bark constituents were significantly correlated and concentration of n-docosanol was highly significantly correlated with all other analytes. Estimates of variance components revealed the highest variation among populations for ursolic acid (66%) and the lowest for β-sitosterol (20%). In general, environmental parameters recorded (temperature, precipitation, altitude) for the samples sites were not correlated with the concentration of most constituents; however, concentration of ferulic acid was significantly correlated with annual precipitation. Because the concentration of compounds in bark extracts may be affected by tree size, the diameter of sampled plants at 1.3m tree height (as proxy of age) was recorded. The only relationship with tree diameter was a negative correlation with ursolic acid. Under the assumption that genetically less variable populations have less variable concentrations of bark compounds, correlations between variation parameters of the concentration and the respective genetic composition based on chloroplast and nuclear DNA markers were assessed. Only variation of β-sitosterol concentration was significantly correlated with haplotypic diversity. The fixation index (F(IS)) was positively correlated with the variation in concentration of ferulic acid. Principal Components Analysis (PCA) indicated a weak geographic pattern. Mantel tests, however, revealed associations between the geographic patterns of bioactive constituents and the phylogenetic relationship among the populations sampled. This suggests an independent evolution of bark metabolism within different phylogeographical lineages, and the molecular phylogeographic pattern is partly reflected in the variation in concentration of bark constituents. The results have important implications for the design of strategies for the sustainable use and conservation of this important African tree species.

Evaluation of different extraction approaches for the determination of phenolic compounds and their metabolites in plasma by nanoLC-ESI-TOF-MS

Sample preparation is an important step for the determination of phenolic compounds in biological samples. Different extraction methods have been tested to determine phenolic compounds and their metabolites in plasma by nano-liquid chromatography coupled to electrospray ionisation-time-of-flight mass spectrometry (nanoLC-ESI-TOF-MS). The sample treatment optimisation was performed using commercial foetal bovine serum spiked with representative phenolic standards, namely naringenin, luteolin, verbascoside, apigenin, rutin, syringic acid and catechin. Different protein-precipitation conditions were evaluated as well as enzymatic digestion with trypsin and solid-phase extraction using different phases such as C-18, ABN and ENV+, working at different pH values. The optimum extraction procedure consisted of a previous protein-precipitation step using HCl 200 mmol/L in methanol for 2.5 h at 50 °C followed by a solid-phase extraction using C-18 cartridges at pH 2.5. This procedure was finally applied to the plasma of rats overfed with a phenolic-rich Lippia citriodora extract. These samples were analysed by nanoLC-ESI-TOF-MS, enabling the identification of five compounds previously found in the administered L. citriodora extract and one metabolite.

A metabolite-profiling approach to assess the uptake and metabolism of phenolic compounds from olive leaves in SKBR3 cells by HPLC-ESI-QTOF-MS

Olive leaves, an easily available natural low-cost material, constitute a source of extracts with significant antitumor activity that inhibits cell proliferation in several breast-cancer-cell models. In this work, a metabolite-profiling approach has been used to assess the uptake and metabolism of phenolic compounds from an olive-leaf extract in the breast-cancer-cell line SKBR3 to evaluate the compound or compounds responsible for the cytotoxic activity. For this, the extract was firstly characterized quantitatively by high-performance liquid chromatography coupled to electrospray ionization-quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS). Then, SKBR3 cells were incubated with 200 μg/mL of the olive-leaf extract at different times (15 min, 1, 2, 24, and 48 h). A metabolite-profiling approach based on HPLC-ESI-QTOF-MS was used to determine the intracellular phenolic compounds, enabling the identification of 16 intact phenolic compounds from the extract and four metabolites derived from these compounds in the cell cytoplasm. The major compounds found within the cells were oleuropein, luteolin-7-O-glucoside and its metabolites luteolin aglycone and methyl-luteolin glucoside, as well as apigenin, and verbascoside. Neither hydroxytyrosol nor any of its metabolites were found within the cells at any incubation time. It is proposed that the major compounds responsible for the cytotoxic activity of the olive-leaf extract in SKBR3 cells are oleuropein and the flavones luteolin and apigenin, since these compounds showed high uptake and their antitumor activity has been previously reported.

Secondary metabolites from the stems of Engelhardia roxburghiana and their antitubercular activities

Bioassay-guided fractionation of stems of Engelhardia roxburghiana led to isolation of: four diarylheptanoids, engelheptanoxides A-D (1-4); two cyclic diarylheptanoids, engelhardiols A (5) and B (6); one naphthoquinone dimer, engelharquinonol (7); and one 1-tetralone, (4S)-4,6-dihydroxy-1-tetralone (8), along with 24 known compounds (9-32). The structures of 1-8 were by spectroscopic analysis. Compounds 5, 6, 13, 22, and 23 showed antitubercular activity against Mycobacterium tuberculosis H(37)Rv with MIC values of 72.7, 62.1, 9.1, 15.3, and 70.1μM, respectively.

Intestinal ellagitannin metabolites ameliorate cytokine-induced inflammation and associated molecular markers in human colon fibroblasts

Pomegranate ellagitannins (ETs) are transformed in the gut to ellagic acid (EA) and its microbiota metabolites, urolithin A (Uro-A) and urolithin B (Uro-B). These compounds exert anti-inflammatory effects in vitro and in vivo. The aim of this study was to investigate the effects of Uro-A, Uro-B, and EA on colon fibroblasts, cells that play a key role in intestinal inflammation. CCD18-Co colon fibroblasts were exposed to a mixture of Uro-A, Uro-B, and EA, at concentrations comparable to those found in the colon (40 μM Uro-A, 5 μM Uro-B, 1 μM EA), both in the presence or in the absence of IL-1β (1 ng/mL) or TNF-α (50 ng/mL), and the effects on fibroblast migration and monocyte adhesion were determined. The levels of several growth factors and adhesion cytokines were also measured. The mixture of metabolites significantly inhibited colon fibroblast migration (∼70%) and monocyte adhesion to fibroblasts (∼50%). These effects were concomitant with a significant down-regulation of the levels of PGE(2), PAI-1, and IL-8, as well as other key regulators of cell migration and adhesion. Of the three metabolites tested, Uro-A exhibited the most significant anti-inflammatory effects. The results show that a combination of the ET metabolites found in colon, urolithins and EA, at concentrations achievable in the intestine after the consumption of pomegranate, was able to moderately improve the inflammatory response of colon fibroblasts and suggest that consumption of ET-containing foods has potential beneficial effects on gut inflammatory diseases.