Phenolic composition, antioxidant capacity and α-glucosidase inhibitory activity of raw and boiled Chilean Araucaria araucana kernels

Evaluation of antioxidant, antimicrobial, and bioactive properties and peptide sequence composition of Malatya apricot kernels

BACKGROUND

This study used four different apricot (Prunus armeniaca) kernels cultivated in Malatya during two consecutive years. The varieties were Hacihaliloglu, Hasanbey, Kabaasi, and Zerdali. The physicochemical properties of the kernels were determined, and the bioactive content of the kernels was evaluated using kernel hydrolysates prepared using trypsin.

RESULTS

With regard to the physicochemical properties of the kernels, the dry matter ratio and protein content were the highest in the Hacihaliloglu variety; the ash ratio was the highest in the Kabaasi variety, and the free oil ratio was the highest in the Hasanbey variety. The bioactive compound content changed according to kernel variety. Angiotensin-converting enzyme inhibitors activity was found to be the highest in the Hacihaliloglu and Hasanbey varieties, which had the lowest amygdalin content, and Zerdali had the highest amygdalin content. The antioxidant and antimicrobial effects of the kernels varied, with Hasanbey and Kabaasi generally having the highest content in both analyses. Moreover, a concentration of 20 mg mL-1 of the hydrolysate was determined to have a destructive effect for the microorganisms used in this study. The storage protein of the kernels, except Hacihaliloglu, was found to be Prunin 1, with the longest matching protein chain in the kernels being R.QQQGGQLMANGLEETFCSLRLK.E.

CONCLUSION

The results suggest that the peptide sequences identified in the kernels could have antihypertensive, antioxidative, and Dipeptidyl peptidase IV (DPP-IV) inhibitory effects. Consequently, apricot kernels show potential for use in the production of functional food products. Of the kernels evaluated in this study, Hacihaliloglu and Hasanbey were deemed the most suitable varieties due to their higher bioactive content and lower amygdalin content. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Antioxidant capacity and inhibition of metabolic syndrome-associated enzymes by Cryptocarya alba fruits

The fruits of the native tree Cryptocarya alba Mol. (Lauraceae), known as "peumo" were consumed by the Mapuche Amerindians in Chile both raw and after boiling. The aim of this work was to compare the content of phenolic, procyanidins, antioxidant capacity and inhibition of enzymes related with metabolic syndrome (α-glucosidase, α-amylase and pancreatic lipase) from the phenolic enriched extracts (PEEs) of peumo fruits. Fruits were collected during two years in three different places in central Chile and were investigated raw, boiled, and after separation into cotyledons and peel. The water resulting from the fruit decoction was also analyzed. The composition of the PEE was assessed by HPLC-DAD-MS/MS and the main compounds were quantified by HPLC. The strong inhibitory effect on α-glucosidase, with IC50 values below 1 µg/mL for several samples, was related, at least in part, to the content of 3-caffeoylquinic acid, 5-caffeoylquinic acid and (-)-epicatechin. The effect of the PEE on pancreatic lipase is of interest and can be partially explained by the (-)-epicatechin content. PCA analyses showed a clear separation of the samples according to the fruit parts and processing. However, no differences by geographic origin were observed. The activity of peumo PEEs on enzymes related to metabolic syndrome and its antioxidant capacity support further studies on the health promoting properties of this native Chilean food plant.

Phenolic characterization of fermented jujube puree by HPLC-MS/MS and their release during in vitro dynamic digestion

Health benefits of fruit products fermented with probiotics are partially attributed to their increased contents of phenolic compounds. In this study, the effect of in vitro dynamic gastrointestinal digestion on the release of phenolic compounds and changes in the antioxidant activity of jujube puree fermented with Streptococcus thermophilus was investigated. Thirteen target phenolic compounds were characterized by high-performance liquid chromatography-tandem mass spectrometry. The recovery of this developed method ranged from 87.41% to 111.03%, and the limits of detection and quantification were low. Fermentation with Streptococcus thermophilus significantly increased the contents of most phenolic compounds in jujube puree. Fermentation reduced the decrease in the contents of most phenolic compounds in jujube puree during gastrointestinal digestion and, as a consequence improved the antioxidant capacity of digested fractions. These findings indicated that fermentation could increase the bioaccessibility of specific phenolics in jujube, as well as the antioxidant activity of this fruit.

Bioactive Activities of the Phenolic Extract from Sterile Bracts of Araucaria angustifolia

Sterile bracts can represent 80% of Araucaria angustifolia pinecone and are a rich source of phenolic compounds. This study aimed to optimize the extraction of the phenolic compounds from Araucaria angustifolia bracts using response surface methodology; the bioactivity properties were also investigated. The effects of the ethanol concentration, solute/solvent ratio, and temperature in relation to the phenolic composition and antioxidant activity were evaluated. The quantification and identification of the individual phenolic compounds (using high-performance liquid chromatography) and their bioactivity were evaluated. The optimized extraction conditions, which detected gallic acid, catechin, epicatechin, quercetin, and kaempferol, were obtained using 60% ethanol at a ratio of 1:38 (w/v) and a temperature of 80 °C. The extract showed high levels of phenolic classes and antioxidant activity. The extract also showed an inhibitory activity for pathogenic (approximately 80%, 10,000 µg/mL) and lactic acid (27.9%, 15,000 µg/mL) bacteria strains. The α-glucosidase inhibitory activity was approximately ten times greater than acarbose, demonstrating its high antiglycemic potential. No antioxidant and anti-inflammatory cellular activity were determined; however, a high cytotoxicity for non-tumor cells and the antiproliferative activity against the tumor cells were observed. Overall, the phenolic extract showed promising action in relation to the fight against the diseases related to oxidative stress and, hopefully, the application of the safe concentrations of the extract, based on bioavailability assays, can be verified.

Potential biomedical applications of Araucaria araucana as an antispasmodic, bronchodilator, vasodilator, and antiemetic: Involvement of calcium channels

ETHNOPHARMACOLOGICAL RELEVANCE

Since pre-Columbian era, the resin of Araucaria araucana tree has been used traditionally for the treatment of ulcers and wounds. Araucaria species have also been used to treat inflammation, respiratory problems, viral infections, ulcers, and rheumatoid, cardiovascular, and neurological disorders.

AIMS AND OBJECTIVE

Due to its popular use, the authors aimed to scrutinize the potential of this plant as an antispasmodic and an antiemetic agent. Furthermore broncho- and vasodilatory effects of this plant was explored to rationalize its folkloric uses.

MATERIALS AND METHODS

Araucaria araucana crude extract (Aa.Cr) was evaluated in isolated preparations of rabbit jejunum, trachea, aorta, and atria to investigate the antispasmodic, bronchodilator, and vasodilator effects. The potential mechanistic approaches were compared with the standard drug 'verapamil'. The antiemetic activity was determined and compared with the standard drug 'domperidone' via chick emesis model.

RESULTS

Aa.Cr dose-dependently relaxed both spontaneous and K⁺-induced contractions in the isolated jejunum preparations of rabbits. In concentration-response curves of calcium (Ca⁺⁺), Aa.Cr also triggered the rightward shift like verapamil. Applying carbachol and phenylephrine (1 μM) and K+ (80 mM) to the isolated tracheal and aortic tissue preparation, respectively, resulted in broncho- and vasodilatory activities, respectively which may be due to the inhibition of Ca++ channels. Aa.Cr inhibited atrial force and spontaneous contractions in the rabbit's right atria. Aa.Cr exhibited significant antiemetic activity (P < 0.001 vs. saline) in dose-dependent (50-150 mg/kg) manner like domperidone. In silico molecular docking was performed to investigate the biological targets of purified components of Aa.Cr which revealed that cadinol dominantly targets β2 receptors to cause bronchodilation, however, eudesmin binds non-specifically to all the selected targets, while secoisolariciresinol mediated high hydrogen bonding with muscarinic receptors (M1 and M3) and Ca⁺⁺ channels, thus shows the suggested mechanistic pathways of targeted activities.

CONCLUSIONS

The results of this study indicates that Aa.Cr may exhibit antispasmodic activity, bronchodilation, and vasodilation by inhibiting voltage-dependent Ca⁺⁺ channels and release of subcellular calcium. This explains its folkloric use in hypertension, bronchospasms, gastrointestinal spasms, and emesis.

Evaluation of antioxidant, enzyme inhibition, nitric oxide production inhibitory activities and chemical profiles of the active extracts from the medicinal and edible plant: Althaea officinalis

To develop the medicinal and edible plant resources of Althaea officinalis Linn in Europe and other places, this study concentrated on the bioactive ingredients of its different extracts. The phytochemical compositions of MeOH extracts were evaluated by UPLC-DAD-ESI-Q-TOF-MSⁿ analysis. The in vitro antioxidant properties, enzymes inhibitory effects and nitric oxide (NO) production inhibitory activities of fractions obtained from the aerial parts of Althaea officinalis (APAO) were evaluated. The results identified 76 compounds, including 8 phenolic acids, 17 flavonoids, 6 coumarins, 9 triterpenes and 11 alkaloids. Fr. C-2 of APAO was found to have the highest TPC (175.8 ± 1.5 mg GAE/g) and TFC (466.9 ± 5.0 mg RE/g) with the highest antioxidant capacity in DPPH, ABTS, CUPRAC, FRAP and β-carotene bleaching assays. Fr. A showed noticeable inhibition of α-glucosidase with an IC₅₀ value of 3.8 ± 0.1 μg/mL. However, Fr. B displayed stronger inhibitory activity on 5-lipoxygenase than quercetin, with the IC₅₀ value of 8.4 ± 1.6 μg/mL. In addition, Fr. B also possessed potent inhibitory activities on NO production toward LPS-activated RAW 264.7 Cells with an IC₅₀ value of 15.7 ± 1.6 μg/mL. Our findings suggest that different Althaea officinalis extracts may be considered sources of phenolic and flavonoid compounds with high potential as natural antioxidants, anti-inflammatory agents and blood sugar regulators. In addition, they can also be used in food and nutraceutical products with enhanced bioactivities.

The Hierarchical Contribution of Organic vs. Conventional Farming, Cultivar, and Terroir on Untargeted Metabolomics Phytochemical Profile and Functional Traits of Tomato Fruits

In this work, the impact of terroir, cultivar, seasonality, and farming systems on functional traits of tomato was hierarchically investigated. Untargeted metabolomics, antioxidant capacity, colorimetric assays, and enzyme inhibition were determined. The total phenolic and carotenoid contents significantly varied between growing years, whereas an interaction between the farming system and growing year (p < 0.01) was observed for total phenolics, carotenoids, and flavonoids, and for acetylcholinesterase inhibition. Hierarchical clustering showed that geographical origin and growing year were the major contributors to the differences in phytochemical profiles. Nonetheless, supervised modeling allowed highlighting the effect of the farming system. Several antioxidants (L-ascorbic acid, α-tocopherol, and 7,3',4'-trihydroxyflavone) decreased, whereas the alkaloid emetine and phytoalexin phenolics increased under organic farming. Taken together, our findings indicate that cultivar and pedo-climatic conditions are the main determinants for the functional quality of tomato, whereas the farming system plays a detectable but hierarchically lower.

Bioactivity screening of pinhão (Araucaria Angustifolia (Bertol.) Kuntze) seed extracts: the inhibition of cholinesterases and α-amylases, and cytotoxic and anti-inflammatory activities

The objective of this work was to determine the potential bioactive properties of extracts from bio-residues of pinhão (Araucaria angustifolia (Bertol.) Kuntze) seeds, namely the α-amylase and cholinesterase inhibition, cytotoxicity, and anti-inflammatory properties. The pinhão extracts evaluated were obtained from cooking water (CW) and as an ethanolic extract from residual pinhão seed shells (PS). Catechin was the major compound found in both extracts. The PS extract presented higher antioxidant levels and the better inhibition of human salivary and porcine pancreatic α-amylases when compared to the CW extract. Also, based on in vivo evaluations, the PS extract did not differ significantly from acarbose when compared to a control group. The most potent inhibitor of cholinesterases was the CW extract. No cytotoxicity toward normal cells was detected, and neither extract showed anti-inflammatory activity. The PS extract presented cytotoxic activity toward non-small-cell lung, cervical, hepatocellular and breast carcinoma cell lines. Overall, the results demonstrated the potential bioactivity of extracts obtained from pinhão bio-residues.

Antiglycating Effect of Phenolics from the Chilean Currant Ribes cucullatum under Thermal Treatment

Numerous dietary polyphenols possess antiglicating activity, but the effects of thermal treatment on this activity are mostly unknown. The effect of thermal treatment in the antiglycating activity of polyphenolic enriched extracts (PEEs) from Ribes cucullatum towards glyoxal-induced glycation of sarcoplasmic proteins was assessed. Sarcoplasmic proteins from chicken, beef, salmon, and turkey, were incubated 2 h at 60 °C with and without glyoxal and different concentrations of PEEs (0.25, 0.5, 1, and 5 mg/mL). The antiglycating activity was evaluated by: (1) Lys and Arg consumption, (2) Carboxymethyl lysine (CML) generation, and (3) lipid-derived electrophiles inhibition in a gastric digestion model. Protective effects were observed against CML generation in proteins and a decrease of electrophiles in the gastric digestion model. A dose-dependent consumption of Lys and Arg in proteins/PEEs samples, indicated the possible occurrence of quinoproteins generation from the phenolics. Protein/PEEs incubations were assessed by: (1) High pressure liquid chromatography analysis, (2) Gel electrophoresis (SDS-PAGE), and (3) Redox cycling staining of quinoproteins. Protein/PEEs incubations produced: (1) Decrease in phenolics, (2) increase of protein crosslinking, and (3) dose-dependent generation of quinoproteins. We demonstrate that phenolic compounds from R. cucullatum under thermal treatment act as antiglycating agents, but oxidative reactions occurs at high concentrations, generating protein crosslinking and quinoproteins.