Inhibitory effect of chestnut (Castanea mollissima Blume) inner skin extract on the activity of α-amylase, α-glucosidase, dipeptidyl peptidase IV and in vitro digestibility of starches

This study aimed to investigate the inhibitory effect of chestnut inner skin extract (CISE) on the activity of postprandial blood sugar-related enzymes. In total, 12 flavonoids were identified by HPLC-TOF-MS. CISE showed strong and weak inhibition on α-amylase and α-glucosidase, with the IC₅₀ of 27.2 and 2.3 μg/mL, respectively. The inhibition modes of CISE against α-amylase and α-glucosidase were mixed-type and non-competitive type, respectively. Epicatechin gallate noncompetitively inhibited α-amylase, α-glucosidase and dipeptidyl peptidase IV (DPP-IV). Analysis by ultraviolet-visible spectroscopy, fluorescence spectroscopy and circular dichroism suggested that flavonoids altered the hydrophobicity and microenvironment of these enzymes. CISE decreased the starch bioavailability by reducing the enzymatic hydrolysis rate and increasing the fraction of undigested starch. The extract reduced the rapidly digestible starch and increased the resistant starch after incorporation into A-, B- or C- crystallinity starch. Thus, the chestnut inner skin is a useful resource for regulating postprandial blood sugar level.

Ohmic heating polyphenolic extracts from vine pruning residue with enhanced biological activity

Vine Pruning residue was submitted to conventional heating and ohmic heating (OH) for the extraction of bioactive compounds and analyzed for total phenolic content (TPC), polyphenolic profile, antioxidant activity, antimicrobial activity and anticancer activity. The OH extracts were obtained using Low electric field (496.0 V/cm) or Intermediate electric field - IEF (840.0 V/cm). The tests were performed using 45% (v/v) ethanol-water extraction solution at 80 °C at different extraction times (20-90 min). The extract that stood out among the others concerning anticancer potential was the one obtained by OH when used, IEF, where the TPC was significantly higher than in the other extracts which correlated with higher antioxidant, antimicrobial and anti-proliferative activity on different tumor cell lines (HepG2, MDA-MB-231, MCF-7 and Caco2). Vine pruning OH extracts obtained using green solvents by an eco-friendly procedure were revealed as a source of compounds with relevant antioxidant and anticancer activity.

Safety assessment of Morus nigra L. leaves: Acute and subacute oral toxicity studies in Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Morus nigra L. is a plant native to Asia, and well adapted to the Brazilian climate. It is popularly known as "amoreira preta", and is part of the National List of Plants of Interest to the Brazilian Unified Health System. It is used in folk medicine mainly to soften the effects of menopause, as anti-inflammatory, antidiabetic and antihypertensive. However, information on safe doses and use is still precarious.

AIM OF THE STUDY

To identify the chemical composition of the ethanolic extract of Morus nigra L. leaves (EEMN), as well as perform a toxicological study in male and female rats.

MATERIALS AND METHODS

The chemical composition of the extract was performed by HPLC/DAD. In the acute study, the dose administered was 2000 mg/kg, and signs of toxicity and mortality was observed. In the sub-acute study, the extract was administered at doses of 500, 750 and 1000 mg/kg for 28 days. Behavioral changes, object recognition test, renal and hepatic tissue assessments, biochemical and hematological parameters were determined. The extract was administered orally to male and female rats in both studies.

RESULTS

Quercetin and caffeic acid showed as major compounds in the extract. In the acute treatment, the extract was classified as safe (category 5), according to the protocol. In the subacute study, there was a decrease in AST in males (750 and 1000 mg/kg) and females (1000 mg/kg), reduction of total cholesterol in females (750 and 1000 mg/kg), and increase in renal and hepatic change the LPO levels.

CONCLUSION

The present investigation showed that EEMN did not present significant toxic effects when administered orally. Moreover, presented a potentially protective action of organs and possesses hypocholesterolemic activity, thus, it is shown as a promising natural source to be used in pharmacology.

Carbohydrates, volatile and phenolic compounds composition, and antioxidant activity of calabura (Muntingia calabura L.) fruit

Soluble carbohydrates, volatile and phenolic compounds from calabura fruit as well as its antioxidant activity were assessed. The low amount of fermentable oligo-, di-, and monosaccharides and polyols (FODMAPs) and similar amount of glucose and fructose allow us to classify the calabura berry as low-FODMAPs. The terpenes β-Farnesene and dendrolasin identified by SPME-GC-MS were the major volatile components. UHPLC-MS/MS analysis revelled gallic acid (5325 μg/g dw) and cyanidin-3-O-glucoside (171 μg/g dw) as the main phenolic compounds, followed by gentisic acid, gallocatechin, caffeic acid and protocatechuic acid. In addition, gallic acid was found mainly in esterified (2883 μg/g dw) and insoluble-bound (2272 μg/g dw) forms. Free and glycosylated forms showed however the highest antioxidant activity due to occurrence of flavonoids (0.28-27 μg/g dw) in these fractions, such as catechin, gallocatechin, epigallocatechin, naringenin, and quercetin. These findings clearly suggest that calabura is a berry with low energy value and attractive colour and flavour that may contribute to the intake of several bioactive compounds with antioxidant activity. Furthermore, this berry have great potential for use in the food industry and as functional food.

Application of metabolomics profiling in the analysis of metabolites and taste quality in different subtypes of white tea

Three subtypes of white tea, Silver Needle (SN), White Peony (WP), and Shou Mei (SM), differ in their taste, aroma, bioactivity, and commercial value. Here, a metabolomics investigation on the chemical compositions combining taste equivalent-quantification and dose-over-threshold (DoT) determination on the taste qualities were applied to comprehensively characterize the white tea subtypes for the first time. Significant differences in the contents of catechins, dimeric catechins, amino acids, phenolic acids, flavonol/flavone glycosides, and aroma precursors were observed among these 3 white teas. Metabolite content comparison and partial least-squares (PLS) analysis suggest that theanine, aspartic acid, asparagine, and AMP were positively correlated with the umami taste in white tea, and flavan-3-ols, theasinensins, procyanidin B3, and theobromine had positive correlations with higher bitterness and astringency tastes. In addition, puckering astringent (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG) and theogallin, bitter-tasting caffeine, and the mouth-drying/velvety-like astringent γ-aminobutyric acid (GABA) were identified as key taste compounds of white tea infusion by absolute quantification and DoT factor calculations. This work provided systematic and comprehensive knowledge on the chemical components, taste qualities, and sensory active metabolites for the subtypes of white tea.

Ultrasonic-assisted extraction combined with sample preparation and analysis using LC-ESI-MS/MS allowed the identification of 24 new phenolic compounds in pecan nut shell [Carya illinoinensis (Wangenh) C. Koch] extracts

Ultrasonic-assisted extraction combined with statistical tools (factorial design, response surface methodology and kinetics) were used to evaluate the effects of the experimental conditions of temperature, solid-to-solvent ratio, ethanol concentration and time for the extraction of the total phenolic content from pecan nut shells. The optimal conditions for the aqueous and hydroalcoholic extract (with 20% v/v of ethanol) were 60 and 80 °C; solid to solvent ratio of 30 mL·g^-1 (for both) and extraction time of 35 and 25 min, respectively. Using these optimize extraction conditions, 426 and 582 mg GAE·g^-1 of phenolic compounds, from the aqueous and hydroalcoholic phases respectively, were obtained. In addition, the analysis of the phenolic compounds using the LC-ESI-MS/MS system allowed the identification of 29 phenolic compounds, 24 of which had not been reported in literature for this raw material yet.

Rhizoma Smilacis Glabrae inhibits pathogen-induced upper genital tract inflammation in rats through suppression of NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizoma Smilacis Glabrae (RSG) is traditionally used to treat gynecological disease, which is simply recorded in Chinese Pharmacopoeia. However, whether it has effect on upper genital tract inflammation (UGTI) is unclear.

AIM OF THE STUDY

To evaluate the pharmacological effect of RSG on UGTI in rats and analyze its phytochemistry characteristics.

MATERIALS AND METHODS

The substances in RSG extract was qualified by LC-Q-TOF-MS method, and 11 substances were further quantified. The RSG extract, at dose of 241, 482 (clinical dose) and 964mg/kg/day, was orally administered to UGTI rats whose upper genital tracts were multi-infected with pathogens. Infiltrations of neutrophil and lymphocyte and productions of IL-1β, IL-6, CXCL-1, MCP-1, RANTES, PGE2, COX-2, NF-κB p65 and IκB-α in upper genital tract were examined to evaluate the effects of RSG and its potential mechanism.

RESULTS

A total of 77 substances were detected in RSG extract, with 50 substances putatively identified, most of which were flavonoids, phenolic acids and phenylpropanoids. The quantification analysis showed flavonoid had a relative high amount. In pharmacological study, RSG extract suppressed infiltrations of inflammatory cells, reduced over-productions of factors involved in inflammation and pelvic pain. A potential mechanism of these effects was blocking NF-κB signal pathway.

CONCLUSIONS

The RSG extract exhibited anti-inflammatory effect on UGTI, with a potential mechanism of blocking the activation of NF-κB signal pathway. The effect may be involved in the presence of substances, such as flavonoids and phenolic acids.

Characterization of white tea metabolome: Comparison against green and black tea by a nontargeted metabolomics approach

White tea is considered the least processed form of tea and is reported to have a series of potent bioactivities, such as antioxidant, anti-inflammatory, anti-mutagenic, and anti-cancer activities. However, the chemical composition of white tea and the dynamic changes of the metabolites during the manufacturing process are far from clear. In this study, we applied a nontargeted metabolomics approach based on ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS) to comprehensively profile the characteristic metabolites of white tea. There were significant differences in the content of amino acids, catechins, dimeric catechins, flavonol and flavone glycosides, and aroma precursors in white tea compared with green and black teas that were manufactured from the same fresh tea leaves. Furthermore, the dynamic changes of the metabolites in the tea samples with various withering durations of 0, 4, 8, 12, 16, 20, 24, 28, and 36 h were also profiled. This study offers a comprehensive characterization of the metabolites and their changes in white tea.

Combination of Ligusticum chuanxiong and Radix Paeoniae ameliorate focal cerebral ischemic in MCAO rats via endoplasmic reticulum stress-dependent apoptotic signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Combination of Ligusticum chuanxiong and Radix Paeoniae (XS) is highly effective in the treatment for focal cerebral ischemic, but the underlying mechanism is not clear. This study was conducted to evaluate the combinative effects of XS on MCAO rats and explore the underlying mechanisms.

MATERIALS AND METHODS

MCAO rats were used to evaluate the protective effect of Ligusticum chuanxiong (CX), Radix Paeoniae Rubra (CS) and their combination (XS) on ameliorating focal cerebral ischemic. Cerebral ischemia deficits and infarct size were performed by 2,3,5-triphenyltetrazolium chloride (TTC) and hematoxylin-eosin (H-E) staining. Activities of SOD, CAT and GSH-Px, as well as levels of LPO and MDA were detected by commercial kits while ELISA kits for the content of plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator (PA). Immunohistochemistry (IHC) and western blot analysis (WB) were carried out to examine the protein expressions including PKR-like endoplasmic reticulum kinase (PERK), cytoplasmic of glucose regulated protein 78 (GRP78), X box-binding protein-1 (XBP-1), activating transcription factor-6 (ATF-6), C/EBP-homologous protein (CHOP), metalloprotease-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), Bcl-2 associated X protein (Bax), and porcineB-cellleukemia/lymphoma-2 (Bcl-2) in brain tissues. Reverse transcription polymerase chain reaction (RT-PCR) and Quantitative PCR (Q-PCR) were applied to examine vascular endothelial growth factor (VEGF) and N-methyl-d-aspartate receptors (NMDAR1) mRNA levels.

RESULTS

CX, CS and their combination (XS) could reduce cerebral ischemia deficits and infarct size of MCAO rats. They increased SOD, CAT and GSH-Px activities, and reduced MDA and LPO levels in serum, markedly. A significant decrease of endoplasmic reticulum stress-related factors PERK, XBP-1, ATF-6 and CHOP protein expression levels while an increase of GRP78 and MVD expression by the treatment of CX, CS and XS. It could also be observed that their treatment could reduce apoptotic damage of brain tissues by up-regulating Bax level and down-regulating Bcl-2 level. Furthermore, the levels of MMP-9 and PAI-1 in serum and tissues of rats were down-regulated remarkably while TIMP-1 and PA levels were up-regulated. VEGF mRNA level was up-regulated dramatically whereas NMDAR1 was reduced. Importantly, the combination of CX and CS, namely XS, has a more meaningful improvement on focal cerebral ischemic than CX or CS alone.

CONCLUSION

All these revealed that the combined XS exerted more remarkable protective effects than alone. XS could inhibit neuronal apoptosis by attenuating ER-stress-dependent apoptotic signaling and protected the blood-brain barrier. These findings might supply beneficial hints for the synergy of CX and CS, and provide the basis for rationality of XS preparation and deserve further clinical investigations.

Identification of Vitis vinifera L. grape berry skin color mutants and polyphenolic profile

A germplasm set of twenty-five grapevine accessions, forming eleven groups of possible berry skin color mutants, were genotyped with twelve microsatellite loci, being eleven of them identified as true color mutants. The polyphenolic profiling of the confirmed mutant cultivars revealed a total of twenty-four polyphenols, comprising non-colored compounds (phenolic acids, flavan-3-ols, flavonols and a stilbene) and anthocyanins. Results showed differences in the contribution of malvidin-3-O-glucoside to the characteristic Pinot Noir anthocyanins profile. Regarding the two Pique-Poul colored variants, the lighter variant was richer than the darker one in all classes of compounds, excepting anthocyanins. In Moscatel Galego Roxo the F3'H pathway seems to be more active than F3'5'H, resulting in higher amounts of cyanidin, precursor of the cyanidin derivatives. As far as we are aware, this is the first time that a relationship between the content of polyphenolic compounds is established in groups of grape berry skin color mutant cultivars.

Comparison of phenolic profiles and antioxidant properties of European Fagopyrum esculentum cultivars

The purpose of this study was to investigate composition and content of phenolic compounds in seeds of common buckwheat (Fagopyrum esculentum Moench) cultivars from Western, Central and Southeastern Europe grown in the Balkan area, and to compare them with cultivars from the Balkan. Mostly detected hydroxycinnamic acids in seeds of the investigated cultivars were caffeic and chlorogenic acid derivatives. More than ten different flavanols were detected in the investigated seeds, based on which all tested buckwheat cultivars were divided into two groups: those with high propelargonidins (epiafzelechin-epicatechin) and those with high procyanidins contents. 'Novosadska' had the highest level of phenolic acids, proanthocyanidins, flavones and most of the flavonols. However, 'Bosna 1' and 'Bosna 2' were highlighted with the greatest rutin content (up to 46 times higher than in other cultivars). All buckwheat cultivars had quite high antioxidant capacity (more than 80% of neutralized radicals), yet, 'Novosadska', 'Godijevo', 'Spacinska 1' and 'Bamby' excelled.