Phenolic profiles, bioaccessibility and antioxidant activity of plum (Prunus Salicina Lindl)

Postharvest ripening-induced modification of cell wall polysaccharide affects plum phenolic bioavailability

The mechanisms by which cell wall polysaccharides regulate phenolic release are essential to human health. Scanning electron microscopy (SEM), surface area and porosimetry analyzer, high-performance liquid chromatography (HPLC), and atomic force microscopy (AFM) indicated that compared to fresh plums, postharvest ripening reduced chain linearity in the homogalacturonan region of pectins and the degree of branching of RG-I; pectin and hemicellulose underwent solubilization and depolymerization by cell wall-degrading enzymes; and the specific surface area of cellulose was reduced by 19.5 %-26.8 %, with aggregation of cellulose occurring. In addition, confocal laser scanning microscopy (CLSM), polyphenol adsorption experiments, and in vitro gastrointestinal digestion experiments showed that the cell wall modifications under postharvest ripening process induced phenolics release and increased the bioaccessibility of plums: compared to the fresh plums, the equilibrium adsorption capacity of the cell wall of late postharvest ripened plums was reduced by 42.6 % (for epicatechin) and 27.4 % (for chlorogenic acid), and the bioaccessibility index of postharvest plum phenolics was increased by 11.2 %-23.9 %. These findings indicate cell wall modification under postharvest ripening process induces phenolic release and improves plum phenolic bioavailability.

Metabolic profile of procyanidin A2 by human intestinal microbiota and their antioxidant and hypolipidemic potential in HepG2 cells

PURPOSE

Procyanidins have strong potential for antioxidation and decreasing hepatic fat accumulation thus preventing non-alcoholic fatty liver disease (NAFLD). Procyanidin A2 (PCA2), predominately found in cranberries, avocado, peanut red skins and litchi fruit pericarp, is poorly absorbed in the gastrointestinal tract. However, literatures about its metabolic profile by gut microbiota and effects on lipid metabolism are limited. Therefore, the metabolites of PCA2 by human intestinal microbiota as well as their antioxidant and hypolipidemic potential were investigated.

METHODS

PCA2 was incubated with human intestinal microbiota and the metabolites produced were characterized by UPLC-Q-TOF-MS. The antioxidant and hypolipidemic potential of PCA2 and its microbial metabolites (MPCA2) were evaluated and compared.

RESULTS

The metabolism of PCA2 resulted in the formation of 14 metabolites, and the highest antioxidant capacity values were reached after 6 h incubation. In addition, PCA2 and MPCA2 were effective in reducing oxidative stress and lipid accumulation induced by oleic acid (OA) in HepG2 cells. They significantly promoted the phosphorylation of AMP-activated protein kinase (AMPK) and thus stimulated hepatic lipolysis by up-regulating of the expression of carnitine palmitoyl transferase I (CPT-I) and suppressed hepatic lipogenesis by down-regulation of the expression of 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMG-CoA) reductase, fatty acid synthase (FAS) and sterol regulatory element binding proteins 1c (SREBP-1c).

CONCLUSION

Our results indicated that PCA2 and MPCA2 were effective to prevent OA-induced lipid accumulation and oxidative stress in HepG2 cells, implying that microbial metabolites may play a crucial role in the realization of human health effects of PCA2.

Starch-based composite formulation of chickpea flour and black carrot (Daucus carota l.) pomace in extruded snacks: In vitro gastrointestinal behavior and stability of bioactive compounds

Black carrot pomace (BCP) is a by-product of colorant production, containing various valuable components with the health promoting effects. In this study, for the first time, BCP was incorporated into a starch-based extruded snack formulation using wheat semolina and corn starch. Total phenolic content, total antioxidant capacity, phenolics, and anthocyanins after processing and in vitro gastrointestinal digestion were investigated, and physical and textural properties of the snack products were determined. Incorporating BCP significantly raised the TPC and antioxidant levels, notably achieving peak levels in snacks enriched with 20 % BCP. The phenolic acids and anthocyanins were increased significantly (48-382 %) (p < 0.05) with simulated gastric digestion whereas no anthocyanins were detected after simulated intestinal digestion. On the other hand, the extrusion process resulted in a negative impact on anthocyanin concentrations, particularly marked by a significant reduction in some cyanidin derivatives indicating the detrimental effect of extrusion on the molecular integrity of anthocyanins under high temperature and pressure, leading to their degradation. In the final product, the snacks displayed lower expansion indices, water absorption index, water solubility index, and lightness; but had higher hardness and redness values compared to the control and turned slightly darker. The study proposes to evaluate BCP as a value-added ingredient that imparts functional properties to foods along with the utilization of starch in the extrusion process. Additionally, the integration of wheat semolina and corn starch contributed to the structural integrity and texture of the extruded snacks, highlighting the importance of polysaccharides in the formulation.

Characteristic of volatile flavor compounds in 'Fengtangli' plum (Prunus salicina Lindl.) were explored based on GC×GC-TOF MS

Introduction

The 'Fengtangli' plum (Prunus salicina Lindl.) is favoured by consumers for its characteristic flavor. The purpose of this study was to explore the characteristics of volatile flavor compounds in 'Fengtangli' plum.

Methods

The flavor compounds of both 'Fengtangli' and 'Siyueli' plums were analyzed using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOF MS).

Results

The results revealed the presence of 495 volatile flavor compounds in 'Fengtangli' plum and 466 in 'Siyueli' plum. The relative concentrations of hydrocarbons, alcohols, ketones, and esters in 'Fengtangli' plum were significantly elevated compared to those detected in 'Siyueli' plum. Moreover, the sensorial attributes of sweetness, citrus, herbal, floral, and fruity notes were more prominent in 'Fengtangli' plum relative to those of 'Siyueli' plum. Through the integration of differential metabolite analysis and relative odor activity assessment, it is hypothesized that furan-2-pentyl; (E)-2-octenal; and 1-octen-3-one may represent the characteristic of volatile flavor compounds in 'Fengtangli' plum.

Discussion

The research results may provide a theoretical reference for the development and application of 'Fengtangli' plum and the study of the synthesis mechanism of characteristic flavor compounds.

A comparative evaluation of the composition and antioxidant activity of free and bound polyphenols in sugarcane tips

The sugarcane tip is abundant in phenolic compounds. Previous studies have concentrated on the effects of free polyphenols, while bound polyphenols were overlooked. In this study, the content of bound polyphenols (SPB) (31.9 ± 0.9 mg GAE/g DW) was significantly higher than free polyphenols (SPF) (3.4 ± 0.1 mg GAE/g DW). A total of 44 free and 31 bound phenolics were identified by the UPLC-EIS-QTOF-MS/MS. Moreover, the antioxidant activity of SPB was more pronounced, as evidenced by its higher ABTS+ and DPPH scavenging rates than SPF, which was attributed to the higher tannin content. Furthermore, at all tested concentrations (100 and 200 μg/mL), SPB significantly enhanced the survival and antioxidant enzyme activity of Caenorhabditis elegans (C. elegans), while concurrently reducing ROS levels. High concentrations of SPB even exhibited antioxidant activity comparable to Vitamin C (Vc). The collective findings strongly indicate that SPB holds great potential as an effective antioxidant.

Effect of ultrasound-assisted extraction on phenolic profile, bio-accessibility, OVCAR-3, and SKOV-3 cytotoxicity in blackthorn (Prunus spinosa L.)

This study aimed to examine the extraction of specific phenolic compounds from blackthorn using ultrasound-assisted extraction (UAE) and to evaluate the influence of UAE on the phenolic composition, bioaccessibility, and cytotoxic effect evaluated on ovarian cancer (OVCAR-3 and SKOV-3) and healthy (HaCaT) cell lines. The UAE parameters were optimized by modeling with the response surface method. Temperature, time, and ultrasound amplitude were utilized to determine the optimal extraction conditions. Optimization experiments were conducted to assess the influence of independent variables on the maximum concentrations of six phenolic compounds identified via high-performance liquid chromatography (HPLC) and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. The optimal conditions for UAE were determined as an extraction temperature of 33.177°C, a duration of 4.334 min, and an amplitude of 38.980%. The phenolic profile of the extract obtained under optimized UAE conditions (B-UAEopt) was re-examined, confirming that it remained consistent at the individual component level. Using an in vitro digestion model, UAE was found to increase the bioaccessibility of antioxidant activity in the small intestine. The IC50 values for OVCAR-3 were 64 and 67 mg mL-1 for blackthorn and B-UAEopt, while the IC50 values for SKOV-3 were 53 mg mL-1 and 50 mg mL-1 for blackthorn and B-UAEopt, respectively. This study showed that UAE is an exceptionally effective method for extracting phenolic compounds from blackthorn, as it preserves the phenolic profile, enhances bioaccessibility, and maintains cytotoxic effects without any detrimental impact.

Soluble sugar, organic acid and phenolic composition and flavor evaluation of plum fruits

Plums (Prunus salicina and Prunus domestica) are prevalent in southwestern China, and have attracted interest owing to their delectable taste and exceptional nutritional properties. Therefore, this study aimed to investigate the nutritional and flavor properties of plum to improve its nutritional utilization. Specifically, we determined the soluble sugars, organic acids, and phenolic components in 86 accessions using high-performance liquid chromatography. Notably, glucose, fructose, malic, and quinic acids were the predominant sweetness and acidity in plums, with sucrose contributing more to the sweetness of the flesh than the peel. Moreover, The peel contains 5.5 fold more phenolics than flesh, epicatechin, gallic acid, and proanthocyanidins C1 and B2 were the primary sources of astringency. Correlation and principal component analyses showed eight core factors for plum flavor rating, and a specific rating criterion was established. Conclusively, these findings provide information on the integrated flavor evaluation criteria and for enhancing optimal breeding of plums.

The synergistic effects of rice bran rancidity and dephenolization on digestive properties of rice bran protein

Both rice bran (RB) rancidity and dephenolization could affect the structural characteristics and phenolics composition of rice bran protein (RBP), thereby affecting RBP digestibility. The synergistic effects of RB rancidity and dephenolization on RBP digestibility were investigated. Excessive RB rancidity (RB stored for 10 d) and non-dephenolization reduced RBP digestibility, while moderate RB rancidity (RB stored for 1 d) combined with dephenolization improved RBP digestibility to a maximum of 74.19%. Dephenolization reduced the antioxidant capacities of RBP digestive products. The digestibility of non-dephenolized RBP (NDRBP) was significantly (P < 0.05) related with its carbonyl content, surface hydrophobicity, and ζ-potential. The digestibility of dephenolized RBP (DRBP) was significantly related with its β-sheet structure content, surface hydrophobicity, ζ-potential, and average particle size. Overall, moderate RB rancidity combined with dephenolization enhanced RBP digestibility by reducing the non-competitive inhibition of endogenous phenolics on protease and regulating the spatial structural characteristics of RBP.

The Release of Organic Acids and Low Molecular Weight Carbohydrates from Matcha Tea After In Vitro Digestion

BACKGROUND/OBJECTIVES

This study tested the influence of in vitro digestion on the release of organic acids and low molecular weight saccharides of matcha.

METHODS

The concentrations of analytes in the raw and undigested portion of matcha were measured using HPLC with spectrometric and refractometric detection to establish their residual values after a two-step enzymatic digestion that was finally presented as a retention factor.

RESULTS

It was established that dry matter digestibility values after simulated gastric and both gastric and intestinal phases were 67.3 and 85.9%, respectively. Native matcha, citric acid (44.8 mg/g), malic acid (32.2 mg/g), trehalose (36.1 mg/g), and L-arabinose (8.20 mg/g) reached the highest values and were predominant, whereas D-fructose, xylose, maltose, and saccharose were not detected. Regarding gastric phase digestion, succinic and malic acids, trehalose and D-glucose were the worst-releasing compounds and their remaining factors reached 34, 19, 18, and 50%, respectively, whereas L-arabinose was completely released. Focusing on gastric and small intestinal digestion, the least-releasing compounds of matcha tea leaves were succinic acid and trehalose, with their retention factors at 7 and 13%, which can proceed with the leaf matrix to the large intestine.

CONCLUSIONS

Malic, oxalic, and citric acids, the carbohydrates D-glucose, L-arabinose, and L-rhamnose, are almost entirely released from matcha tea during digestion in the stomach and small intestine and can be available for absorption in the small intestine. In the measurement of oxalic acid, considering that the process of shading tea leaves increases the concentration of this acid and its retention factor value is too small, it would be appropriate in the future to evaluate the recommended maximum daily intake of matcha tea for people sensitive to the formation of urinal stones.

Evaluation of the Enzyme Inhibition, Antioxidant, and Antimicrobial Activities of Apricots, Plums, and Their Hybrid Fruits

The current study focuses on evaluating the enzyme inhibition (acetylcholinesterase, α-amylase, α-glucosidase, pancreatin lipase), antioxidant, and antimicrobial activities of the "Modesto" apricot, "Stanley" plum, and their hybrid the "Stendesto" plum-apricot. The "Stendesto" is the only successful plum-apricot hybrid in Bulgaria. A spectrophotometric approach was used to evaluate the antioxidant activity following four complementary assays (DPPH, ABTS, FRAP, and CUPRAC). The "Stendesto" plum-apricot revealed its enhanced antioxidant potential compared to its parental lines. Apart from the free phenolics extraction, two other techniques (alkaline and acid hydrolysis) were applied to reveal the biological potential of the studied fruit. Not only free but also bound phenolic extracts were able to inhibit α-glucosidase and acetylcholinesterase, while none of the extracts inhibited lipase or α-amylase. None of the apricot extracts had antimicrobial activity, while the other fruit had limited antimicrobial activity. The proposed results undoubtedly reveal that hybrid fruits possess enhanced biological activity compared to their parents. This is a first comprehensive evaluation of hybrid fruits with reference to parental lines. This makes them an interesting research topic that should be better explored.

Chemical Characterization of Pruning Wood Extracts from Six Japanese Plum (Prunus salicina Lindl.) Cultivars and Their Antitumor Activity

The Japanese plum tree (Prunus salicina Lindl.) is mainly cultivated in temperate areas of China and some European countries. Certain amounts of wood (from pruning works) are generated every year from this crop of worldwide commercial significance. The main objective of this work was to value this agricultural woody residue, for which the chemical composition of pruning wood extracts from six Japanese plum cultivars was investigated, and the antiproliferative activity of extracts and pure phenolics present in those extracts was measured. For the chemical characterization, total phenolic content and DPPH radical-scavenging assays and HPLC‒DAD/ESI‒MS analyses were performed, with the procyanidin (-)-ent-epicatechin-(2α→O→7,4α→8)-epicatechin (5) and the propelargonidin (+)-epiafzelechin-(2β→O→7,4β→8)-epicatechin (7) being the major components of the wood extracts. Some quantitative differences were found among plum cultivars, and the content of proanthocyanidins ranged from 1.50 (cv. 'Fortune') to 4.44 (cv. 'Showtime') mg/g of dry wood. Regarding the antitumoral activity, eight wood extracts and four phenolic compounds were evaluated in MCF-7 cells after 48 h of induction, showing the wood extract from cv. 'Songold' and (‒)-annphenone (3), the best antiproliferative activity (IC50: 424 μg/mL and 405 μg/mL, respectively).

Exploring the anti-inflammatory ingredients and potential of golden buckwheat (Fagopyrum dibotrys) on the TLR4/NLRP3 pathway in acute lung injury

Golden buckwheat, also called Fagopyrum dibotrys (D. Don) H. Hara, is a plant of the genus Buckwheat in the buckwheat family. The aim of this study was to screen the bioactive ingredients of golden buckwheat extract and investigate the protective effect on acute lung injury (ALI). The ethyl acetate extract (EAE) was identified as the active fraction in LPS-induced RAW264.7 cells, with gallic acid, proanthocyanidin B2, and epicatechin at 0.0563%, 0.3707%, and 0.3868%, respectively. At the same time, 20 compounds (mainly flavonoids and organic acids) were identified by UPLC-Q-Exactive Orbitrap-HRMS in EAE. Furthermore, the EAE reduced lung histopathology scores in mice with ALI, decreased the dry-to-wet weight ratio of lung tissue, and significantly inhibited the concentrations of IL-1β, TNFα, and IL-6 in bronchoalveolar lavage fluid (BALF). It also reduced the number of leukocytes, decreased the activity of MPO in lung tissue, and inhibited the levels of TLR4/NLRP3 pathway mRNA and protein in lung tissue. Our study indicated that golden buckwheat as a source of functional food prevents or treats associated lung diseases by modulating the activation of the TLR4/NLRP3 signaling pathway.

Insights on the Extraction and Analysis of Phenolic Compounds from Citrus Fruits: Green Perspectives and Current Status

Citrus fruits (CF) are highly consumed worldwide, fresh, processed, or prepared as juices and pies. To illustrate the high economic importance of CF, the global production of these commodities in 2021 was around 98 million tons. CF's composition is considered an excellent source of phenolic compounds (PC) as they have a large amount and variety. Since ancient times, PC has been highlighted to promote several benefits related to oxidative stress disorders, such as chronic diseases and cancer. Recent studies suggest that consuming citrus fruits can prevent some of these diseases. However, due to the complexity of citrus matrices, extracting compounds of interest from these types of samples, and identifying and quantifying them effectively, is not a simple task. In this context, several extractive and analytical proposals have been used. This review discusses current research involving CF, focusing mainly on PC extraction and analysis methods, regarding advantages and disadvantages from the perspective of Green Chemistry.

Effects of steam explosion on raspberry leaf structure and the release of water-soluble nutrients and phenolics

Raspberry leaves were subjected to steam explosion at 0.5 and 1.0 MPa for 60-120 s, aiming to disrupt their physical and chemical structure and, consequently, promote the release of phenolic compounds into the leaf aqueous infusion. Under optimal condition of 1.0 MPa for 60 s, steam explosion led to a notable 23 % increase in total phenolic content, a 29 % elevation in ABTS radical scavenging capacity, and a 13 % rise in DPPH radical scavenging capacity of the aqueous infusion. Utilizing UHPLC-Q-TOF-MS/MS and UHPLC-QE-MS/MS techniques, respectively, a total of 39 phenolic compounds were identified from raspberry leaves, and the changes in the contents of the most important 11 species were analyzed following steam explosion. Through correlation analysis and considering the content of each phenolic compound, it was inferred that the heightened antioxidant capacity of the aqueous infusion primarily stemmed from a substantial increase in the release of ellagic acid after steam explosion.

Exploring the bioaccessibility and intestinal absorption of major classes of pure phenolic compounds using in vitro simulated gastrointestinal digestion

The bioaccessibility and bioavailability of phenolic compounds (PC) influence directly their role in disease prevention/control. Studies have evaluated this ability through complex plant and food matrices, which may reflect more a synergistic effect of the matrix than the ability of the PCs, hindering their individual exploitation in nutraceutical or pharmaceutical applications. In the present study ten pure PCs representing major classes were evaluated for their bioaccessibility and intestinal absorption in an in vitro simulated gastrointestinal digestion (SGD). This is the first study concerning the bioaccessibility evaluation of pure phloretin, phloroglucinol, naringin, naringenin and daidzein, while no in vitro SGD has been performed before for the other compounds considered here. PCs were analyzed through ultra-high-performance liquid chromatography coupled with diode-array detection and tandem mass spectrometry (UHPLC-DAD-MSn). Most of the compounds remained present along the gastrointestinal tract, and the bioaccessibility was in general higher than 50%, except for quercetin, epigallocatechin gallate, and ellagic acid. All compounds were highly absorbed in the intestine, with phloretin showing the lowest percentage at about 82%. The study findings provide new knowledge on the bioaccessibility and intestinal absorption of different PCs classes.

Effect of Porphyra haitanensis polyphenols from different harvest periods on hypoglycaemic activity based on in vitro digestion and widely targeted metabolomic analysis

The hypoglycemic effect of Porphyra is well known. Based on in vitro digestion and metabolomics, the bioaccessibility, antidiabetic activity and phenolic conversion of P. haitanensis were investigated at different harvests. Total polyphenol content (TPC), α-glucosidase inhibition and oxygen radical absorbance capacity (ORAC) increased with harvesting and digestion stages, reaching maximum at the fourth harvest. TPC and α-glucosidase inhibition after digestion reached 130-150 mg/g and 50-90 %, ORAC was 8.7-13.5 times higher than the undigestion. However, bioaccessibility in the first and second harvests was 10-80 % higher than other harvests. The phenolic content in the fourth harvest was up-regulated to 2-30 times than the first and mostly were citrus flavonoids. Redundancy analysis indicated significant correlation between phenolic metabolites and bioactivities in different harvests of P. haitanensis during digestion, with the strongest correlation coefficients were apigenin and genistein. This study provides reference for the application of P. haitanensis in treating type 2 diabetes.

The Effects of Different Drying Methods on the In Vitro Bioaccessibility of Phenolics, Antioxidant Capacity, and Morphology of European Plums (Prunes domestica L.)

Four different drying methods, hot-air-drying (HAD), vacuum-drying (VD), ultrasound-assisted vacuum-drying (US-VD), and freeze-drying (FD), were used to obtain dried plums (Prunes domesticaL.). These prunes were evaluated for their physical properties (such as color, rehydration ratio, and microstructural properties), phenolic compounds, and antioxidant activities before and after being subjected to in vitro digestion. TPC (total phenolic content) of plums ranged from 196.84 to 919.58 mg of GAE (gallic acid equivalent)/100 g of dw, and neochlorogenic acid was the most abundant phenolic compound. FD prunes had the highest levels of phenolics, whereas US-VD caused the most significant loss. During in vitro digestion, the phenolics were present at higher levels at the gastric medium but failed to maintain their stability at the small intestinal stage. Among the samples, FD along with HAD prunes exhibited a higher bioaccessibility index for most of the phenolic compounds. The ratios of TPC, TFC (total flavonoid content), and individual phenolics determined in the digested residues to the initial values of the undigested samples ranged from 0.23 to 31.03%. It could be concluded that the majority of the phenolics were extracted during digestion. Our findings showed that the different drying methods would alter the microstructure, which would affect the extractability and release of phenolics in the simulated digestion model.

Nanopore analysis of cis-diols in fruits

Natural fruits contain a large variety of cis-diols. However, due to the lack of a high-resolution sensor that can simultaneously identify all cis-diols without a need of complex sample pretreatment, direct and rapid analysis of fruits in a hand-held device has never been previously reported. Nanopore, a versatile single molecule sensor, can be specially engineered to perform this task. A hetero-octameric Mycobacterium smegmatis porin A (MspA) nanopore modified with a sole phenylboronic acid (PBA) adapter is prepared. This engineered MspA accurately recognizes 1,2-diphenols, alditols, α-hydroxy acids and saccharides in prune, grape, lemon, different varieties of kiwifruits and commercial juice products. Assisted with a custom machine learning program, an accuracy of 99.3% is reported and the sample pretreatment is significantly simplified. Enantiomers such as DL-malic acids can also be directly identified, enabling sensing of synthetic food additives. Though demonstrated with fruits, these results suggest wide applications of nanopore in food and drug administration uses.

The composition of phenolic compounds in Chinese olive (Canarium album L.) cultivars and their contribution to the anti-inflammatory properties of the cultivars

Objective

This study aimed to explore the phenolic compounds (PCs) present in three Chinese olive (Canarium album L.) cultivars and the contribution of these PCs to the anti-inflammatory activities of the cultivars.

Methods

Ultra-high performance liquid chromatography coupled with hybrid quadrupole-orbitrap/mass spectrometry (UPLC-Q-Exactive/MS) was used to identify and quantify the PCs present in three Chinese olive cultivars, "Na zhong," "Tan xiang," and "Xiang zhong". 2,2-diphenyl-1-picrylhydrazyl (DPPH); 2,2'-azinobis (3-ethylbenzothiazoline 6-sulfonate) (ABTS); and oxygen radical absorption capacity (ORAC) assays were used to assess the antioxidant activities of the PCs. Furthermore, we analyzed the anti-inflammatory action of these PCs using lipopolysaccharide (LPS)-induced RAW264.7 cells.

Results

A total of 44 PCs were identified in the three cultivars. Of these, 17 PCs were previously unidentified in Chinese olive. Among the cultivars, the free phenolics (FPs) of "Tan xiang" showed the strongest antioxidant activity. All cultivars have shown significant inhibition of TNF-α and IL-6 production. Clustering correlation analysis showed galloyl-bis-HHDP-glucose and paeonol have significant anti-inflammatory ability in FPs. Quininic, galloylquinic acid, 4-hydroxycinnamic acid and gallic acid hexoside have shown significant inhibition of IL-6 production in BPs. Furthermore, gallic acid, catechin, syringic acid, and nobiletin exhibit negative correlation in FPs and positive correlation in BPs of cytokine production, while corilagin and methyl ellagic acid pentoside exhibited opposite correlation.

Conclusion

In summary, this study contributed to the literature on PCs in Chinese olives and the potential health benefits of FPs and BPs.

Insights into tissue-specific anthocyanin accumulation in Japanese plum (Prunus salicina L.) fruits: A comparative study of three cultivars

In the present study, three matured Japanese plum cultivars with different colored peel and flesh were selected to mine the key transcription factors regulating anthocyanin formation in tissues. Results showed that PsMYB10 was correlated with structural genes C4H, F3H, and ANS. PsMYB6 could positively regulate C4H (r = 0.732) and accumulated anthocyanins in Sanhua plum's flesh. Sanhua plum has the highest phenolic and anthocyanin contents (10.24 ± 0.37 gallic acid equivalent mg g-1 dry weight (DW) and 68.95 ± 1.03 μg g-1 DW), resulting itself superior biological activity as 367.1 ± 42.9 Trolox equivalent mg g-1 DW in oxygen radical absorbance capacity value and 72.79 ± 4.34 quercetin equivalent mg g-1 DW in cellular antioxidant activity value. The present work provides new insights into the regulatory mechanism of tissue-specific anthocyanin biosynthesis, confirming the pivotal role of anthocyanins in the biological activity of plums, providing essential support for the development of horticultural products enriched with anthocyanins.

Gastrointestinal digestion assays for evaluating the bioaccessibility of phenolic compounds in fruits and their derivates: an overview

Fruits and their derivatives are sources of phenolic compounds, which contribute to the maintenance of health benefits. In order to exert such properties, these compounds must be exposed to gastrointestinal conditions during digestion. In vitro methods of gastrointestinal digestion have been developed to simulate and evaluate the changes that compounds undergo after being exposed to various conditions. We present, in this review, the major in vitro methods for evaluating the effects of gastrointestinal digestion of phenolic compounds in fruits and their derivatives. We discuss the concept of bioaccessibility, bioactivity, and bioavailability, as well as the conceptual differences and calculations among studies. Finally, the main changes caused by in vitro gastrointestinal digestion in phenolic compounds are also discussed. The significant variation of parameters and concepts observed hinders a better evaluation of the real effects on the antioxidant activity of phenolic compounds, thus, the use of standardized methods in research would contribute for a better understanding of these changes.

Evaluation of the total phenolic content, antioxidative capacity, and chemical fingerprint of Annona crassiflora Mart. Bioaccessible molecules

Annona crassiflora Mart. (araticum) is an exotic fruit native to the Brazilian Cerrado that stands out for its phytochemical profile, especially for the presence of bioactive compounds. The health-related benefits promoted by these metabolites are widely explored. It is known that the biological activity of bioactive compounds is directly dependent on the availability of the molecules, and their bioaccessibility after the digestion process is one of the main limiting factors. The present study aimed to evaluate the bioaccessibility of bioactive compounds in some parts of araticum (peel, pulp and seeds) fruits obtained from different regions through the in vitro digestion process simulating the gastrointestinal tract. The total phenolic content ranged from 480.81 to 1007.62 for pulp; 837.53 to 1926.56 for peel; and 358.28 to 1186.07 for seeds (mg GAE.100 g^-1 of sample). The highest antioxidant activity was observed for the seeds by the DPPH method, the peel by the ABTS method, and most of the peel, except for the Cordisburgo sample, by the FRAP method. Through the research of the chemical profile, it was possible to list up to 35 compounds, including the nutrients, in this identification attempt. It was observed that some compounds were listed only in natura samples (epicatechin and procyanidin) and others only for the bioaccessible fraction (quercetin-3-O-dipentoside), which is justified by the different gastrointestinal tract conditions. Thus, the present study elucidates that the food matrix will directly influence the bioaccessibility of bioactive compounds. In addition, it highlights the potential of unconventionally used or consumed parts that can be used as sources of substances with biological activities, increasing the sustainability by reducing waste.

Profile and activity of phenolic antioxidants in chrysanthemum (Huangshan Gongju) as affected by simulated digestions

The phenolics are the main bioactive substances of Huangshan Gongju, a famous chrysanthemum of China, but their digestive characteristics are still unknown. To explore the digestive properties of Huangshan Gongju phenolics, the flower was extracted and subjected to simulated digestions, and their phenolic profile and activity were analyzed. The results indicated that the total phenolics content and antioxidant activity of the extract varied with the simulated digestion steps, and they generally decreased in the oral and small intestine digestions but increased in the gastric digestion, and high correlations were detected between the total phenolics content and antioxidant activity (0.873 < r < 0.979, p < .01). The change of phenolic profile during the simulated digestions was similar to that of total phenolics content, and six individual phenolics were identified and quantified, and three of them, including chlorogenic acid, apigenin-7-O-rutinoside, and apigenin-7-O-6″-acetylglucoside showed higher recovery (>64.29%), implying they may be the main functional phenolics of Huangshan Gongju. PRACTICAL APPLICATIONS: This study proved that most phenolics in Huangshan Gongju were relatively stable during digestion. The finding may guarantee the application of Huangshan Gongju in the field of functional foods.

Effects of Pollen Sources on Fruit Set and Fruit Characteristics of 'Fengtangli' Plum (Prunus salicina Lindl.) Based on Microscopic and Transcriptomic Analysis

Adequate yield and fruit quality are required in commercial plum production. The pollen source has been shown to influence fruit set and fruit characteristics. In this study, 'Siyueli', 'Fenghuangli' and 'Yinhongli' were used as pollinizers of 'Fengtangli' plum. Additionally, self-pollination, mixed pollination, and open pollination were performed. We characterized the differences in pollen tube growth, fruit set and fruit quality among pollination combinations. 'Fengtangli' flowers pollinated by 'Fenghuangli' had more pistils with pollen tubes penetrating the ovary and the highest fruit set rate, while the lowest fruit set rate was obtained from self-pollination. In self-pollinated flowers, 33% of pistils had at least one pollen tube reaching the ovary, implying that 'Fengtangli' is partially self-compatible. Pollen sources affected 'Fengtangli' fruit size, weight, pulp thickness, soluble solids, and sugar content. Transcriptome analysis of 'Siyueli'-pollinated and 'Yinhongli'-pollinated fruits revealed 2762 and 1018 differentially expressed genes (DEGs) involved in the response to different pollen sources. DEGs were enriched in plant hormone signal transduction, starch and sucrose metabolism, and MAPK signaling pathways. Our findings provide a reference for the selection of suitable pollinizers for 'Fengtangli' plum and promote future research on the metaxenia effect at the molecular level.

Changes in the Primary Metabolites of ‘Fengtang’ Plums during Storage Detected by Widely Targeted Metabolomics

Plums are one of the most popular stone fruits worldwide owing to their high nutritional value. After harvest, plum fruit quality and flavor change during storage; however, little is known about the changes in metabolites during this period. A comprehensive comparison of primary metabolites in ‘Fengtang’ plum fruits during storage is performed using widely targeted primary metabolomics. A total of 272 primary metabolites were identified by means of ultra-performance liquid chromatography and tandem mass spectrometry (UPLC-MS/MS) in the plums at different storage periods. There was a significant increase in the relative amounts of twenty-eight lipids, twenty amino acids and their derivatives, thirteen organic acids, ten saccharides and alcohols, six nucleotides and their derivatives, and two vitamins. A Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of differential metabolites revealed that glucosinolate biosynthesis, starch and sucrose metabolism, ascorbate and aldarate metabolism, lysine degradation, and other metabolic pathways were significantly enriched; therefore, changes in these metabolic pathways may be key to the quality and flavor change in ‘Fengtang’ plum fruits during storage. Our results provide a theoretical foundation and technical support to evaluate ‘Fengtang’ plum fruit quality.

Characterization, Hypoglycemic Activity, and Antioxidant Activity of Methanol Extracts From Amomum tsao-ko: in vitro and in vivo Studies

The dried fruit of Amomum tsao-ko is well-known as a spice as well as a Chinese traditional herb. This study aimed to identify the bioactive constituents in the powder of methanol extract from Amomum tsao-ko (PMEAT) and to evaluate the hypoglycemic and antioxidant effects of PMEAT, in vitro and in vivo. We identified 36 phytochemicals in PMEAT by employing HPLC-MS/MS. PMEAT solution was found to have potent α-glucosidase-inhibiting activity (IC₅₀, 0.145 mg/mL) in vitro, twice as strong as that of acarbose (IC₅₀, 0.273 mg/mL). To investigate the hypoglycemic activity of PMEAT in vivo, we studied the impact of low-dose PMEAT (the addition of 100 mg/kg PMEAT to the mice diet) and high-dose PMEAT (200 mg/kg PMEAT addition) treatments in STZ-induced diabetic mice. After 6 weeks of intervention, significantly decreased fasting blood glucose (FBG) (p < 0.05), significantly decreased area under the curve (AUC) of the oral glucose tolerance test (p < 0.05), significantly decreased HOMA-IR (p < 0.05), and significantly increased HOMA-β (p < 0.05) were observed in the high-dose PMEAT group. Moreover, we performed an antioxidant activity experiment in vitro. The results showed that PMEAT had a strong ability to scavenge DPPH (IC₅₀, 0.044 mg/mL) as well as ABTS free radicals (IC₅₀, 0.040 mg/mL). In an animal experiment conducted on oxidative damage mice model which was induced by D-glucose and a high-fat diet, we observed significantly increased dismutase (SOD) (p < 0.01), glutathione (GSH) (p < 0.01), and glutathione peroxidase (GSH-Px) (p < 0.01) and significantly reduced malondialdehyde (MDA) and 8-ISO-prostaglandin-PGF2α (8-ISO-PGF2α), after treatment with PMEAT for 90 days. In conclusion, this study reveals the therapeutic potential of Amomum tsao-ko for the treatment of diabetes and helps us discover new antioxidant candidates from natural sources.

Changes in ethylene and sugar metabolism regulate flavonoid composition in climacteric and non-climacteric plums during postharvest storage

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Ethylene metabolism regulated flavonoid (and sugar) contents and composition.

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Ethylene induced anthocyanin and reduced flavonol and flavan-3-ols in plum fruit.

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Anthocyanins positively correlate with sucrose and galactose metabolic pathways.

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Flavonol and flavan-3-ols associated with sorbitol, fructose, and glucose contents.

Plums are rich in flavonoids, key contributors to fruit coloration and putative health benefits. We studied the impact of changes in ethylene and sugars in flavonoid metabolism-related pathways of the climacteric Santa Rosa and its non-climacteric mutant Sweet Miriam, throughout the postharvest period. Fruits were harvested at optimal maturity, subjected to ethylene treatments, and evaluated during storage. We examined transcript profiles of structural and regulatory genes of flavonoid-related pathways and their associated metabolites in skin and flesh, integrated with multivariate analyses of ethylene and sugar metabolism. Ethylene treatments were positively correlated with anthocyanin and negatively correlated with flavonol and flavan-3-ol metabolism. Sucrose and galactose were positively associated with anthocyanin concentration, while sorbitol, fructose, glucose and minor sugars were correlated with flavonol and flavan-3-ol metabolism. Our results support the notion that ethylene is playing key roles in shifting plum fruit flavonoid profiles, which are also associated with changes in fruit sugars.

Free and Bound Phenolic Profiles of Rosa roxburghii Tratt Leaves and Their Antioxidant and Inhibitory Effects on α-Glucosidase

Rosa roxburghii Tratt (R. roxburghii) tea is a traditional Chinese beverage. This study aims to investigate and compare the phenolics in free and bound forms of two cultivars of R. roxburghii leaves, and their bioactivities. The total phenolic content of free and bound fractions was 72.71 and 17.75 mg GAE/g DW in Gui Nong No. 5 (GNN5) and 94.28 and 11.19 mg GAE/g DW in Seedless Cili (SC). A total of 37 phenolic compounds were characterized and quantified by UPLC-Q-Exactive Orbitrap/MS with ellagic acid, quercitrin, isoquercitrin, and quininic acid in free fraction, while gallic acid, ellagic acid, and hyperoside were main compounds in bound fraction. The free fraction with higher phenolic contents also showed excellent performances on antioxidant activities and α-glucosidase inhibitory potency than bound phenolics. Therefore, the results highlight that R. roxburghii leaves are a promising source enriched in phenolic constituents for functional beverages and nutritional foods.

Chemotaxonomic Identification of Key Taste and Nutritional Components in 'Shushanggan Apricot' Fruits by Widely Targeted Metabolomics

The chemotypic and the content variation in taste substances and nutrients in ‘Shushanggan apricot’ fruits were detected by UPLC-MS/MS. A total of 592 compounds were identified, of which sucrose contributed mainly to the sweet taste and malic acid and citric acid were important organic acids affecting sweet–sour taste. γ-linolenic acid, α-linolenic acid and linoleic acid were the dominant free fatty acids, and neochlorogenic acid and chlorogenic acid were the predominant phenolic acids. Fruit taste was positively correlated with sucrose and negatively correlated with malic acid and citric acid. The differential metabolites were significantly enriched in the biosynthesis of amino acids and 2-oxocarboxylic acid metabolism pathways, regulating the sugar and organic acid biosynthesis. Taste and nutrient differences could be revealed by variations in composition and abundance of carbohydrates, organic acids and amino acids. The purpose of this study was to provide a comprehensive chemical characterization of taste and nutrient compounds in ‘Shushanggan apricot’ fruits.

The Effect of In Vitro Digestion on Matcha Tea (Camellia sinensis) Active Components and Antioxidant Activity

This study investigates the effects of in vitro digestion on the antioxidant activity and release of phenolics, xanthine alkaloids, and L-theanine contents of matcha. It establishes digestibility values between 61.2–65.8%. Considering native matcha, the rutin content (303–479 µg/g) reached higher values than catechin (10.2–23.1 µg/g). Chlorogenic acid (2090–2460 µg/g) was determined as predominant. Rutin, quercetin, ferulic, ellagic, and caffeic acid were the least-released phenolics, and their remaining residues reached 76–84%. Protocatechuic, hydroxybenzoic acid, epigallocatechin, and epigallocatechin-3-gallate were the best-released phenolics, with the remaining residues under 1%. Caffeine, L-theanine, and theobromine contents in native matcha reached 16.1, 9.85, and 0.27 mg/g, respectively. Only caffeine (3.66–5.26 mg/g) and L-theanine (0.09–0.15 mg/g) were monitored in the undigested residue, representing 13 and 0.1% of the remaining part, respectively. A chemiluminescence assay showed that water-soluble antioxidants showed significant antioxidant activity in native matcha, while lipid-soluble compounds showed higher antioxidant activity in the undigested samples. Cinnamic and neochlorogenic acids were determined as the main contributors to the ACW values in the undigested matcha, epicatechin, and quercetin in the ACL fraction. The application of the digestion process reduced the antioxidant activity by more than 94%. SEM has proved specific digestion patterns of in vitro digestibility of matcha.

An Upgraded, Highly Saturated Linkage Map of Japanese Plum (Prunus salicina Lindl.), and Identification of a New Major Locus Controlling the Flavan-3-ol Composition in Fruits

Japanese plum fruits are rich in phenolic compounds, such as anthocyanins and flavan-3-ols, whose contents vary significantly among cultivars. Catechin (C) and epicatechin (EC) are flavan-3-ol monomers described in the fruits of this species and are associated with bitterness, astringency, antioxidant capacity, and susceptibility to enzymatic mesocarp browning. In this study, we aimed to identify quantitative trait loci (QTL) associated with the content of flavan-3-ol in Japanese plum fruits. We evaluated the content of C and EC in the mesocarp and exocarp of samples from 79 and 64 seedlings of an F1 progeny (<'98-99' × 'Angeleno'>) in the first and second seasons, respectively. We also constructed improved versions of linkage maps from '98-99' and 'Angeleno,' presently called single-nucleotide polymorphisms (SNPs) after mapping the already available GBS reads to Prunus salicina Lindl. cv. 'Sanyueli' v2.0 reference genome. These data allowed for describing a cluster of QTLs in the cultivar, 'Angeleno,' associated with the flavan-3-ol composition of mesocarp and exocarp, which explain up to 100% of the C/EC ratio. Additionally, we developed a C/EC metabolic marker, which was mapped between the markers with the highest log of odds (LOD) scores detected by the QTL analysis. The C/EC locus was located in the LG1, at an interval spanning 0.70 cM at 108.30-108.90 cM. Our results suggest the presence of a novel major gene controlling the preferential synthesis of C or EC in the Japanese plum fruits. This study is a significant advance in understanding the regulation of synthesizing compounds associated with fruit quality, postharvest, and human health promotion.

Cancer protective effects of plums: A systematic review

Plums is one of the most cultivated stone fruits due to its fast growing popularity. It has various traditionally recognized health benefits. There are two main commercial types of plums: the European plum (Prunus domestica) and the Japanese plum (Prunus salicina), each having many varieties. Researchers are gathering further evidence of pharmacological effects for plums by scientifically studying its anti-inflammatory, antioxidant properties. A systematic review analysing the literature related to the effects of plums on prevention and treatment of cancer is warranted. This is the first review examining the cancer-related effects of plums. Antioxidation properties of the active constituents of plum were also compared. Scopus, Google Scholar, PubMed, Medxriv and Cochrane Library databases, from their date of inception until July 2021 were utilized. The risk of bias was assessed using CONSORT checklist. A total of 6639 studies were screened and eventually only 54 studies were included. Full-text review of included studies revealed that plum extracts were rich in antioxidants. Overall, most of the studies that fulfilled the eligibility criteria were in vitro and a few clinical studies involving in vivo work. Therefore, it would be beneficial to perform more studies on animals or humans, to confirm that the result obtained from these in vitro studies are able to be extrapolated in a wider range of applications. Further clinical and in vivo studies are warranted to validate plums as a functional food for treatment and prevention of cancer.

Assembly of the Complete Mitochondrial Genome of Chinese Plum (Prunus salicina): Characterization of Genome Recombination and RNA Editing Sites

Despite the significant progress that has been made in the genome sequencing of Prunus, this area of research has been lacking a systematic description of the mitochondrial genome of this genus for a long time. In this study, we assembled the mitochondrial genome of the Chinese plum (Prunus salicina) using Illumina and Oxford Nanopore sequencing data. The mitochondrial genome size of P. salicina was found to be 508,035 base pair (bp), which is the largest reported in the Rosaceae family to date, and P. salicina was shown to be 63,453 bp longer than sweet cherry (P. avium). The P. salicina mitochondrial genome contained 37 protein-coding genes (PCGs), 3 ribosomal RNA (rRNA) genes, and 16 transfer RNA (tRNA) genes. Two plastid-derived tRNA were identified. We also found two short repeats that captured the nad3 and nad6 genes and resulted in two copies. In addition, nine pairs of repeat sequences were identified as being involved in the mediation of genome recombination. This is crucial for the formation of subgenomic configurations. To characterize RNA editing sites, transcriptome data were used, and we identified 480 RNA editing sites in protein-coding sequences. Among them, the initiation codon of the nad1 gene confirmed that an RNA editing event occurred, and the genomic encoded ACG was edited as AUG in the transcript. Combined with previous reports on the chloroplast genome, our data complemented our understanding of the last part of the organelle genome of plum, which will facilitate our understanding of the evolution of organelle genomes.

Investigation on the Phytochemical Composition, Antioxidant and Enzyme Inhibition Potential of Polygonum Plebeium R.Br: A Comprehensive Approach to Disclose New Nutraceutical and Functional Food Ingredients

The present work describes medicinal potential and secondary metabolic picture of the methanol extract (PP-M) of Polygonum plebeium R.Br. and its fractions; hexane (PP-H), ethyl acetate (PP-E) and water (PP-W). In total bioactive component estimation, highest contents of phenolic (89.38±0.27 mgGAE/g extract) and flavonoid (51.21±0.43 mgQE/g extract) were observed in PP-E, and the same fraction exhibited the highest antioxidant potential in DPPH (324.80±4.09 mgTE/g extract), ABTS (563.18±11.39 mgTE/g extract), CUPRAC (411.33±15.49 mgTE/g extract) and FRAC (369.54±1.70 mgTE/g extract) assays. In Phosphomolybdenum activity assay, PP-H and PP-E showed nearly similar potential, however, PP-H was the most active (13.54±0.24 mgEDTAE/g extract) in metal chelating activity assay. PP-W was the stronger inhibitor (4.03±0.05 mgGALAE/g extract) of the enzyme AChE, while PP-H was potent inhibitor of BChE (5.62±0.27 mg GALAE/g extract). Interestingly, PP-E was inactive against BChE. Against tyrosinase activity, PP-E was again the most active fraction with inhibitory value of 71.89±1.44 mg KAE/g extract, followed by the activity of PP-M and PP-W. Antidiabetic potential was almost equally distributed among PP-M, PP-H and PP-E. For mapping the chemodiversity of P. plebeium, PP-M was analyzed through UHPLC/MS, which led to the identification of more than 50 compounds. Flavonoids were the main components derived from isovitexin, kaempferol and luteolin however, gallic acid, protocatechuic acid, gingerols and lyoniresinol 9'-sulfate were among important bioactive phenols. These findings prompted to conclude that Polygonum plebeium can be a significant source to offer new ingredient for nutraceuticals and functional foods.

Chemical Profiling and Biological Evaluation of Nepeta baytopii Extracts and Essential Oil: An Endemic Plant from Turkey

Nepeta baytopii is a poorly studied, endemic Nepeta species (Lamiaceae) of Turkey. For the first time, the biological activities (antioxidant, enzyme inhibition, and cytotoxicity properties) of the hexane, ethyl acetate, methanol, water/methanol, and water extracts and essential oil prepared from N. baytopii aerial parts were assessed. Hydro-methanol (41.25 mg gallic acid equivalent (GAE)/g) and water extracts (50.30 mg GAE/g), respectively showed the highest radical scavenging (94.40 and 129.22 mg Trolox equivalent (TE)/g, for 2,2-diphenyl-1-picrylhydrazyl radical and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid radical scavenging assays) and reducing (229.37 and 129.55 mg TE/g, for ferric-reducing antioxidant power and cupric-reducing antioxidant capacity assays) capacities in vitro. An interestingly high inhibition was observed for ethyl acetate extract against butyrylcholinesterase (10.85 mg galantamine equivalent/g). The methanol extract showed high cytotoxicity (31.7%) against HepG2 cells. Caryophyllene oxide was identified in high concentrations in the essential oil (39.3%). Luteolin and apigenin and their derivatives were identified from the methanol and water extracts. The results obtained from this study highlighted that the abundance of highly bioactive compounds from Nepeta baytopii ensures the multiple biological activities of the tested extracts, and this suggests a potential use in the pharmaceutical and nutraceutical fields, and therefore should be investigated further.

Tanacetum vulgare L. (Tansy) as an effective bioresource with promising pharmacological effects from natural arsenal

The Tanacetum genus is a big treasure with the presence of biologically-active compounds and members of this genus are widely used for the treatment of several diseases in traditional medicine system. Considering this fact, we aimed to analyze the extracts from Tanacetum vulgare L. in case of chemical profiles and biological effects. Chemical characterization was performed by using UHPLC-HRMS technique and showed the presence of several phytochemical groups (107 compounds were identified, including phenolic acids, flavonoids, terpenoids and fatty acids. Biological abilities were examined by using antioxidant (DPPH, ABTS, FRAP, CUPRAC, metal chelating and phosphomolybdenum assays) and enzyme inhibition (tyrosinase, amylase, glucosidase and cholinesterase) properties. Pharmaco-toxicological investigations were also performed with the aim to identify limits of biocompatibility, anti-oxidant and neuromodulatory effects, in hypothalamic HypoE22 cells. A bioinformatic analysis was also carried to unravel the putative protein-targets for the observed biological effects. Generally, the tested hexane and hydroalcoholic extracts displayed stronger activities in antioxidant and enzyme inhibitory assays, when compared with water. In addition, multivariate analysis was performed to understand the differences in both solvents and plant parts and we clearly observed the separation of these parameters. The extracts (10 μg/mL) also stimulated DAT and inhibited TNFα and BDNF gene expression, in HypoE22 cells. In parallel, the extracts were also able to stimulate norepinephrine release from this cell line. By contrast, in the concentration range 50-100 μg/mL, the extracts reduced the HypoE22 viability, thus demonstrating cytotoxicity at concentrations 5-10 fold higher compared to those effective as neuromodulatory. Our observations manifested that T. vulgare has several beneficial effects and it can be used as a potential natural raw material for designing further health-promoting applications in nutraceutical, cosmeceutical, and pharmaceutical areas.