Characterization, quantification of free, esterified and bound phenolics in Kainth (Pyrus pashia Buch.-Ham. Ex D.Don) fruit pulp by UPLC-ESI-HRMS/MS and evaluation of their antioxidant activity

UPLC-Q-TOF-MS/MS identification, antioxidant, and alpha-glucosidase inhibition activities of three forms of phenolic compounds from Yemeni jujube fruit: In vitro and in silico investigations

Jujube fruits have rich medicinal value due to their biological properties which are affected mainly by geographical locations. This study investigates the antioxidant properties of free fraction (FF), esterified fraction (EF), bound fraction (BF), and other metabolites prepared from dried Yemeni jujube fruit and compare to those previously reported in the literature. Results from UPLC-Q-TOF-MS/MS analysis showed that this fruit consists of a total of 33, 26, and 27 free, esterified, and bound compounds identified, respectively. In terms of ABTS, DPPH, FRAP, and H2O2 assays, the BF exhibited values 1.2, 1.3,1.3, and 1.4 times higher than those of the FF, and similarly, 1.8, 1.9,2.0, and 2.5 times higher than the EF. A similar trend was observed in the inhibition of α-glucosidase (α-Glu), where the BF was 1.6, and 2.4 times more effective compared to the FF and EF, respectively. In silico analysis showed that flavonoids, the key active compounds, had substantial α-glucosidase binding capacity. In the meat model, all fractions inhibited protein and lipid oxidation during storage, and the BF exhibited the highest antioxidant capacity. This study provides the first investigation of the structure of active compounds and their biological properties in Yemeni jujube fruit. Yemeni fruits can be utilized as natural antioxidants, and nutraceuticals in food preservation, and medicine respectively.

Functional properties of insoluble dietary fibers extracted from different grape pomaces during simulated digestion and in vitro fermentation

This study investigated insoluble dietary fibers (IDFs) extracted from the grape pomaces of Cabernet Sauvignon (CS-IDF), Marselan (MS-IDF), and Merlot (ML-IDF). It explored the release patterns and potential bioactivities of dietary fiber-bound polyphenols from these sources through simulated digestion and in vitro colonic fermentation. The results showed a higher polyphenol content in MS grape skins, which also yielded more IDF. Bound polyphenols were released more effectively during fermentation than during digestion. Caffeic acid and epicatechin disappeared during the fermentation stage, while compounds such as chlorogenic acid, catechin, and myricetin appeared. Gentisic acid was the most abundant monomeric phenolic compound in the fermentation fluid. The released polyphenols exhibited strong antioxidant properties and digestive enzyme inhibitory activity. Fermentation of the IDFs increased propionic acid and total short-chain fatty acid (SCFA) levels, particularly in the CS-IDF and MS-IDF groups. MS-IDF also elevated the relative abundance of Acidaminococcus fermentans, a key SCFA producer. Additionally, all IDFs promoted the growth of beneficial gut bacteria such as Bacteroides H uniformis and Phascolarctobacterium A faecium, while reducing harmful bacteria such as Escherichia. Correlation analysis revealed a positive relationship between released polyphenols and the relative abundance of beneficial gut bacteria, including Parabacteroides B 862006 distasonis and Mitsuokella multacida. These findings suggest that dietary fiber-bound polyphenols exhibit significant bioactivity in the gastrointestinal tract, with MS-IDF showing particular advantages in promoting gut health and bioactive compound release.

Structural Variations of Broccoli Polyphenolics and Their Antioxidant Capacity as a Function of Growing Temperature

Polyphenolics in plants exist in free, soluble-bound, and insoluble-bound structural forms. The concentration of these structural forms depends on the plant's developmental stage, tissue type, soil water availability, and food preparation methods. In this study, for the first time, the effects of growth temperature (RT-room temperature-23 °C day/18 °C night, HT-high temperature-38 °C day/33 °C night, LT-low temperature-12 °C day/7 °C night) on variations of polyphenolic structural forms-free, soluble-bound (esterified and glycosylated), and insoluble-bound-in broccoli (Brassica oleracea L. convar. botrytis (L.) Alef. var. cymosa Duch.) microgreens were investigated. Using spectrophotometric, RP-HPLC, and statistical analyses, it was found that the highest amount of total phenolics (TP) in broccoli microgreens was present in the esterified form, regardless of the temperature at which they were grown (63.21 ± 3.49 mg GAE/g dw in RT, 65.55 ± 8.33 mg GAE/g dw in HT, 77.44 ± 7.82 mg GAE/g dw in LT). LT significantly increased the amount of free (from 13.30 ± 2.22 mg GAE/g dw in RT to 18.33 ± 3.85 mg GAE/g dw) and esterified soluble TP (from 63.21 ± 3.49 mg GAE/g dw in RT to 77.44 ± 7.82 mg GAE/g dw), while HT significantly increased the amount of TP glycosylated forms (from 14.85 ± 1.45 mg GAE/g dw in RT to 17.84 ± 1.20 mg GAE/g dw). LT also enhanced free and esterified forms of total flavonoids, tannins, hydroxycinnamic acids, and flavonols. HT, on the other hand, increased glycosylated forms of TP, flavonoids, tannins, hydroxycinnamic acids, flavonols, and phenolic acids, and decreased insoluble-bound tannins. According to the ABTS method, HT induced antioxidant potential of free and glycosylated forms, while LT increased antioxidant capacity of free forms only. According to the FRAP method, LT increased antioxidant potential of free and esterified polyphenolic forms. Also, based on ABTS and FRAP assays, esterified polyphenolics showed significantly higher antioxidant capacity than any other form. Principal component analysis showed that structural form had a greater impact than temperature. Hierarchical clustering showed that RT-, HT- and LT-broccoli microgreens were most similar in their glycosylated polyphenolics, but differed the most in esterified forms, which were also the most distinct overall. In conclusion, HT and LT induced specific shifts in the structural forms of broccoli polyphenolics and their antioxidant capacity. Based on the results, we recommend applying LT to increase the amount of free and esterified polyphenolics in broccoli microgreens, while HT may be used to enhance glycosylated forms.

UHPLC-MS/MS based comprehensive phenolic profiling, antimicrobial and antioxidant activities of Indian Rhodomyrtus tomentosa fruits

Rhodomyrtus tomentosa fruits, endemic to the Western Ghats were analyzed for its free, bound and esterified phenolics by Ultra High Performance Liquid Chromatography-Mass Spectrometry. Overall, twenty-nine phenolic compounds were identified, amongst them 18 were detected in this fruit for the first time. Gallic acid (80.44 ± 8.74 mg/100 g) and ellagic acid (107.47 ± 7.28 mg/100 g) were the most prominent ones found in the bound phenolic fraction and gallic acid (103.76 ± 6.34 mg/100 g) in the esterified phenolic fraction of the fruit, respectively. Total Phenolic content was found to be highest in bound phenolics (7.09 ± 0.17 mg Gallic acid equivalent/g). The antioxidant and antimicrobial activities of the three extracts namely free, bound and esterified phenolic fruit fractions have been analyzed. Bound phenolics exhibited the highest antioxidant potential (DPPH-15.63 ± 0.86; ABTS-34.73 ± 0.07; FRAP-17.89 ± 0.27 mg/g Ascorbic acid equivalent). The bound phenolics showed good antimicrobial activity against Bacillus cereus, Staphylococcus aureus and Escherichia coli with a MIC of 0.156, 0.625 and 1.25 mg/mL respectively. The exploration of phenolic compounds in Indian variety of Rhodomyrtus tomentosa fruits may provide useful insights on its utilization as a functional food ingredient.

Preparation of hapten and monoclonal antibody of hesperetin and establishment of enzyme-linked immunosorbent assay

Hesperetin is the aglycone of hesperidin and is widely found in the Rutaceae plants and herbal medicines. It exhibits antioxidant, detoxifying, anti-inflammatory, and antimicrobial properties, similar to hesperidin. It has also shown potential in the regulation of certain diseases. In order to detect hesperetin in complex matrix samples such as citrus and herbal, we developed an anti-hesperetin monoclonal antibody and established an indirect competitive enzyme-linked immunosorbent assay (icELISA). The half maximal inhibitory concentration (IC50) was determined to be 2.03 ng/mL, the detection range was 0.39-12.73 ng/mL. In practical sample testing, the concentration of hesperidin measured by icELISA is consistent with the result of UPLC-MS/MS, and the correlation coefficient (R2) is 0.97. These results showed that the established method has good accuracy, reproducibility and broad application prospects, and can be used for the detection of hesperetin in complex matrix samples (such as citrus and herbal samples).

Fractional extraction phenolics from C. oleifera seed kernels exhibited anti-inflammatory effect via PI3K/Akt/NF-κB signaling pathway under Caco-2/RAW264.7 co-culture cell model

Camellia oleifera Abel (C. oleifera) is a multifunctional oilseed, which is rich in many biological active substances with health-promoting properties, especially polyphenols. Previous research revealed that camellia oil phenolics exhibited anti-inflammatory effect, which originated from seed. Thus, we aimed to explore the components of camellia seed phenolics and its potential mechanism of anti-inflammation. Initially, fractional extraction was processed to prepare the phenolics from camellia seed kernels, and we compare four different fractions of phenolics under the LPS-induced Caco-2/RAW264.7 coculturing model. Results showed that free phenolics (FP) had best effect on alleviating pro-inflammatory cytokines (IL-1β, IL-6, IL-8 and TNF-α) compared to esterified-bound phenolics (EP), glycosylated-bound phenolics (GP) and insoluble-bound phenolics (IP). Furthermore, FP reduced inflammation by suppressing the PI3K/Akt/NF-κB signaling pathway and effectively inhibited LPS-induced intestinal permeability increase, tight junction related proteins loss (ZO-1, claudin-1). Same results obtained, as the transepithelial electrical resistance (TEER) and alkaline phosphatase (AKP) activity of high-dose FP treated group was high than model group. Finally, molecular docking was used for evaluating the anti-inflammatory effect for phenolic monomer. KGRG (kaempferol -3-O-(2-O-glucopyranosyl-6-O-rhamnopyranosyl)-glucopyranoside), KXR (kaempferol 3-O-(2''-xylopyranosyl)-rutinoside) and leucoside (kaempferol 3-O-sambubioside) show lower binding energy docking with NF-κB, PI3K and Akt protein, indicating better interactions, which might be effective constituents against inflammation. Subsequently, five major polyphenols were obtained to validate the docking results, especially, indicating the best anti-inflammatory activities of KGRG. Overall, this research sheds insights on the therapy of phenolics from C. oleifera seed towards LPS-induced intestinal inflammation model in vitro and its related mechanism.

Generation, degradation mechanism, and toxicity evaluation of pigmented compounds in Leucosceptrum canum nectar

Leucosceptrum canum nectar (LCN) emerges as a novel food resource, distinguished by its unique dark brown hue. This study delves into the composition and toxicity assessment of novel pigments within LCN. Through liquid chromatography-tandem mass spectrometry (LC-MS/MS) and chemical synthesis, seventeen 2,5-di-(N-(-)-prolyl)-para-benzoquinone (DPBQ) analogs in LCN were identified. These compounds are synthesized in LCN via the Michael addition reaction, utilizing p-benzoquinone (BQ), derived from phenol metabolism, and amino acids as substrates in an alkaline environment (pH = 8.47 ± 0.06) facilitated by dissolved ammonia and the presence of alkaloids. Analytical techniques, including principal component analysis (PCA), orthogonal partial least squares discrimination analysis (OPLS-DA), and volcano plot analysis, were employed to investigate DPBQ analog degradation within the nectar and honey's unique environments. Toxicity assays revealed that DPBQ analogs exhibited no toxicity, displaying a significant difference in toxicity compared to the precursor compound BQ at concentrations exceeding 25 μM.

Insights into the radioprotective efficacy of Pterocarpus santalinus L. aqueous extract

In the present study, we have attempted a comprehensive assessment of the possible radioprotective efficacy of Pterocarpus santalinus aqueous extract (PSAE). All the studied models were gamma-irradiated with prior treatment with PSAE. First, the content of total phenols (4.061 μg/mg gallic acid equivalents), flavonoids (6.616 μg/mg quercetin equivalents), and tannins (0.008 mg/L of PSAE) were determined spectrophotometrically. Second, UHPLC-HRMS analysis was performed to identify the possible radioprotectors. Of those, santalins A & B are known for their usage as natural color in foods and alcoholic beverages identified in PSAE. Treatment was well tolerated with no side effects from PSAE. Later, it was shown that radiation-induced lethality significantly amended in PSAE-treated spleen lymphocytes as evidenced by reduced elevated levels of ROS and lipid peroxidation, restored total thiols and GSH: GSSG, inhibited DNA DSBs and cell death. Furthermore, an immunomodulation study was carried out because radiation exposure induces an inflammatory response. Our study shows that PSAE suppressed concanavalin A-induced T-cell proliferation as evidenced by CFSE dye dilution and CD69 antibody staining methods. Taken together, the current study explored the protective efficacy of PSAE from gamma radiation-inflicted injuries and hence we recommend PSAE as a potent radioprotective formulation.

Polysaccharide-polyphenol interactions: a comprehensive review from food processing to digestion and metabolism

Most studies on the beneficial effects of polyphenols on human health have focused on polyphenols extracted using aqueous organic solvents, ignoring the fact that a portion of polyphenols form complexes with polysaccharides. Polysaccharides and polyphenols are interrelated, and their interactions affect the physicochemical property, quality, and nutritional value of foods. In this review, the distribution of bound polyphenols in major food sources is summarized. The effect of food processing on the interaction between polyphenols and cell wall polysaccharides (CWP) is discussed in detail. We also focus on the digestion, absorption, and metabolic behavior of polysaccharide-polyphenol complexes. Different food processing techniques affect the interaction between CWP and polyphenols by altering their structure, solubility, and strength of interactions. The interaction influences the free concentration and extractability of polyphenols in food and modulates their bioaccessibility in the gastrointestinal tract, leading to their major release in the colon. Metabolism of polyphenols by gut microbes significantly enhances the bioavailability of polyphenols. The metabolic pathway and product formation rate of polyphenols and the fermentation characteristics of polysaccharides are affected by the interaction. Furthermore, the interaction exhibits synergistic or antagonistic effects on the stability, solubility, antioxidant and functional activities of polyphenols. In summary, understanding the interactions between polysaccharides and polyphenols and their changes in food processing is of great significance for a comprehensive understanding of the health benefits of polyphenols and the optimization of food processing technology.

Coffee leaf valorisation into functional wheat flour rusk: their nutritional, physicochemical, and sensory properties

Coffee leaves are currently emerging as a promising agri-food resource rich in phenolics. This study aims to valorise coffee leaf powder (CLP) by incorporating it in refined wheat flour rusk formulations and analyse its physio-chemical, rheological, functional and sensory characteristics. The progressive replacement of CLP improved the dietary fibre (2.51 ± 0.2%), ash (1.09 ± 0.11%), and water absorption capacity (59.7 ± 0.1%) of the flours. It considerably enhanced the falling number and sedimentation values of the flour blends while decreased the loaf volume. Progressive increase in the dietary phenolics (232.21-435.19 mg/100 g), chlorogenic acid (6.0-7.5 mg/100 g), and ABTS antioxidant activity (963.89-1607.25 µMTEAC/g) of the rusks was observed upon CLP addition. Rusks with 3% CLP were found to have significantly acceptable physical and sensory characteristics. Thus, supplementation of CLP in rusk helps in valorising coffee leaves besides providing a functional bakery product to the coffee industry.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-05927-z.

The profiles of free, esterified and insoluble-bound phenolics in peach juice after high pressure homogenization and evaluation of their antioxidant capacities, cytoprotective effect, and inhibitory effects on α-glucosidase and dipeptidyl peptidase-Ⅳ

The phenolic profiles, antioxidant capacities, cytoprotective effect, and α-glucosidase and DPP-IV inhibitory capacity of free (FP), esterified (EP) and insoluble-bound (IBP) phenolic fractions in 'Lijiang snow' peach juice after high pressure homogenization (HPH) were investigated, and the molecular docking was used to explore the enzyme inhibition mechanism. HPH increased total phenolic and total flavonoid contents in three fractions without changing compositions. The IC50 of radicals scavenged by three fractions were all reduced by HPH. The best inhibition on intracellular ROS production were found for phenolic fractions after HPH at 300 MPa, with ROS levels ranged within 95.26-119.16 %. HPH at 300 MPa reduced the apoptosis rates of FP and EP by 16.52 % and 9.33 %, respectively. All phenolic fractions showed effective inhibition on α-glucosidase and DPP-IV by formation of hydrogen bonding and van der Waals forces. This study explored the feasibility of HPH to enhance the phenolics and bioactivity of peach juice.

Phytochemicals and UHPLC-QTOF-HRMS characterisation of bioactives of butterfly pea (Clitoria ternatea L.) seeds and their antioxidant potentials

Clitoria ternatea Linn. (Fabaceae) is a medicinal and ornamental plant, widely used in Ayurvedic and Chinese medicine. There is no strong scientific evidence on the consumption of the tender fruits/seeds of blue- and white-flower plants as vegetables. Analysis of the nutrient composition revealed that the total carbohydrate, protein, and lipid were highest in the mature-stage seeds of both varieties. UHPLC analysis revealed the presence of rutin (1.66 mg%) as the major compound. LC-HRMS confirmed the presence of other bioactives, such as sinapic acid (m/z 223), catechin derivatives (m/z 305 and m/z 153), quercetin (m/z 463), etc., as well. The ascorbic acid content was found to be highest in blue-flowered plant seeds (18.10 mg/100 g). Analysis of antioxidant activity displayed the superiority of immature seeds over mature seeds. The research shows that these seeds are rich in nutrients and bioactives, which may have use in the food and pharmaceutical industries.

Free and Bound Phenolic Profiles and Antioxidant Activities in Melon (Cucumis melo L.) Pulp: Comparative Study on Six Widely Consumed Varieties Planted in Hainan Province

Bound phenolic compounds in the melon pulp have seldom been investigated. This study revealed considerable differences in the total phenolic content (TPC) and antioxidant activity of the free and bound phenolic extracts in the pulps of six melon varieties from Hainan Province, China. Naixiangmi and Yugu demonstrated the highest free TPC, while Meilong showed the highest bound and total TPC and antioxidant activity. UHPLC-QQQ-MS identified and quantified 30 phenolic compounds. The melon cultivars markedly differed in the amount and content of their free and bound phenolic compounds. Xizhoumi No. 25 and Meilong afforded the most phenolic compounds. Hongguan emerged with the highest free phenolic compound content and total content of phenolic compounds; however, Meilong possessed the highest bound phenolic compound content. Hierarchical cluster analysis divided the melon varieties into four different taxa. The present study provides a scientific basis for developing the health-promoting effects of melon pulp.

Recent advances in bio-based extraction processes for the recovery of bound phenolics from agro-industrial by-products and their biological activity

Usually found bound to other complex molecules (e.g., lignin, hemicellulose), phenolic compounds (PC) are widely present in agro-industrial by-products, and their extraction is challenging. In recent times, research is starting to highlight the bioactive roles played by bound phenolics (BPC) in human health. This review aims at providing a critical update on recent advances in green techniques for the recovery of BPC, focusing on enzymatic-assisted (EAE) and fermentation-assisted extraction (FAE) as well as in the combination of technologies, showing variable yield and features. The present review also summarizes the most recent biological activities attributed to BPC extracts until now. The higher antioxidant activity of BPC-compared to FPC-coupled with their affordable by-product source make them medicinally potent and economically viable, promoting their integral upcycling and generating new revenue streams, business, and employment opportunities. In addition, EAE and FAE can have a biotransformative effect on the PC itself or its moiety, leading to improved extraction outcomes. Moreover, recent research on BPC extracts has reported promising anti-cancer and anti-diabetic activity. Yet further research is needed to elucidate their biological mechanisms and exploit the true potential of their applications in terms of new food products or ingredient development for human consumption.

Identification of Key Antioxidants of Free, Esterified, and Bound Phenolics in Walnut Kernel and Skin

Walnut is a natural source of antioxidants. Its antioxidant capacity is determined by the distribution and composition of phenolics. The key phenolic antioxidants in various forms (free, esterified, and bound) in walnut kernel (particularly seed skin) are unknown. The phenolic compounds in twelve walnut cultivars were analyzed using ultra-performance liquid chromatography coupled with a triple quadrupole mass spectrometer in this study. A boosted regression tree analysis was used to identify the key antioxidants. Ellagic acid, gallic acid, catechin, ferulic acid, and epicatechin were abundant in the kernel and skin. The majority of phenolic acids were widely distributed in the free, esterified, and bound forms in the kernel but more concentrated in bound phenolics in the skin. The total phenolic levels of the three forms were positively correlated with antioxidant activities (R = 0.76-0.94, p < 0.05). Ellagic acid was the most important antioxidant in the kernel, accounting for more than 20%, 40%, and 15% of antioxidants, respectively. Caffeic acid was responsible for up to 25% of free phenolics and 40% of esterified phenolics in the skin. The differences in the antioxidant activity between the cultivars were explained by the total phenolics and key antioxidants. The identification of key antioxidants is critical for new walnut industrial applications and functional food design in food chemistry.

UPLC-MS/MS profiling, antioxidant and anti-inflammatory activities, and potential health benefits prediction of phenolic compounds in hazel leaf

Hazel leaf, one of the by-products of hazelnut, which is widely used in traditional folk medicine around the world. In the present study, the profile of free, conjugated, and bound phenolic compounds from hazel leaf was detected and their antioxidant and anti-inflammatory activities were investigated. The potential health benefits of different phenolic compounds were also predicted. The results showed that the 35 phenolic substances of free, conjugated and bound forms were identified including phenolic acids, flavonoids and catechins. Most of the hazel leaf phenolics were presented in free form, followed by conjugated and bound form. All the fractions effectively inhibited the production of reactive oxygen species and malondialdehyde in TBHP-stimulated human umbilical vein endothelial cells by enhancing endogenous superoxide dismutase, and accordingly alleviated inflammatory cytokines (NO, IL-1β, TNF-α, and IL-6) in LPS-stimulated RAW264.7 cells, showing obvious antioxidant and anti-inflammatory capacity. Moreover, combined with network pharmacology, the potential therapeutic effects and functional pathways of hazel leaf phenolics were predicted, which provided value basis for exploring their treatment on diseases and developing health products in the future.

Importance of Insoluble-Bound Phenolics to the Antioxidant Potential Is Dictated by Source Material

Insoluble-bound phenolics (IBPs) are extensively found in the cell wall and distributed in various tissues/organs of plants, mainly cereals, legumes, and pulses. In particular, IBPs are mainly distributed in the protective tissues, such as seed coat, pericarp, and hull, and are also available in nutritional tissues, including germ, epicotyl, hypocotyl radicle, and endosperm, among others. IBPs account for 20-60% of the total phenolics in food matrices and can exceed 70% in leaves, flowers, peels, pulps, seeds, and other counterparts of fruits and vegetables, and up to 99% in cereal brans. These phenolics are mostly covalently bound to various macromolecules such as hemicellulose, cellulose, structural protein, arabinoxylan, and pectin, which can be extracted by acid, alkali, or enzymatic hydrolysis along with various thermal and non-thermal treatments. IBPs obtained from various sources exhibited a wide range of biological activities, including antioxidant, anti-inflammatory, antihypertensive, anticancer, anti-obesity, and anti-diabetic properties. In this contribution, the chemistry, distribution, biological activities, metabolism, and extraction methods of IBPs, and how they are affected by various treatments, are summarized. In particular, the effect of thermal and non-thermal processing on the release of IBPs and their antioxidant potential is discussed.

Hand-Portable Miniaturized Liquid Chromatography for the Determination of Chlorogenic Acids in Dietary Supplements

With the explosive growth of the dietary supplements industry, new demands have emerged that cannot be faced with the sophisticated instrumentation available in well-equipped laboratories. In particular, there is a demand for simplified and easy-to-use instruments, capable of providing results in short times of analysis. In this study, a hand-portable miniaturized liquid chromatograph (portable LC) has been tested for the determination of chlorogenic acids (CGAs) in products intended to supplement the diet and elaborated with green coffee extracts. CGAs offer several health benefits due to their antioxidant properties, and an increasing number of dietary supplements are marketed with claimed high contents of these compounds. The results obtained with the proposed portable LC approach have been compared with those obtained with two other miniaturized benchtop liquid chromatography instruments, namely, a capillary liquid chromatograph (capLC) and a nano liquid chromatograph (nanoLC). Although compared with the methods that used the benchtop instruments, the sensitivity attainable was lower, the portable LC instrument provided a comparable analytical performance for the quantification of the main GCAs at low mg g^-1 levels, and it was clearly superior in terms of speed. The proposed portable LC-based method can be applied to assess the content and distribution profile of the predominant CGAs in this kind of dietary supplement. It can be also used to estimate the antioxidant power due to CGAs, as well as their preservation state.

Comprehensive Nutritional Analysis, Antioxidant Activities, and Bioactive Compound Characterization from Seven Selected Cereals and Pulses by UHPLC-HRMS/MS

Cereals and pulses comprise the largest proportion in a typical Indian diet plate. This research mainly focuses on determining the nutritional composition, bioactive compound characterization, and antioxidant activities of seven selected cereals and pulses. The total carbohydrate content was high in unripe banana (67.65/100 g) and arrowroot (63.76/100 g). Finger millet (44.55 μmol %), chickpea (53.33 μmol %), and green gram (17.40 μmol %) showed high oleic, linoleic, and linolenic acid contents, respectively. The ascorbic acid content was the highest in chickpea and horse gram at 86.83 and 83.76 mg/100 g, respectively. The major phenolics and flavonoids quantified and confirmed using HPLC and UHPLC-HRMS/MS were gallic, protocatechuic, vanillic, para-coumaric, ferulic, chlorogenic, sinapic, and trans-cinnamic acids, rutin, and quercetin. The sample extracts showed dose-dependent antioxidant activity to combat the reactive oxygen species. Hence, these serve as an excellent source for the development of functional food formulations for lowering the risk of various diseases.

Extract of Murraya koenigii selectively causes genomic instability by altering redox-status via targeting PI3K/AKT/Nrf2/caspase-3 signaling pathway in human non-small cell lung cancer

BACKGROUND

Lung cancer is the leading cause of cancer-related death worldwide. Dietary bioactives have been used as alternative therapeutics to overcome various adverse effects caused by chemotherapeutics. Curry leaves are a widely used culinary spice and different parts of this plant have been used in traditional medicines. Curry leaves are a rich source of multiple bioactives, especially polyphenols and alkaloids. Therefore, extraction processes play a key role in obtaining the optimum yield of bioactives and their efficacy.

PURPOSE

We aim to select an extraction process that achieves the optimum yield of bioactives in curry leaves crude extract (CLCE) with minimum solvent usage and in a shorter time. Further, to investigate the anticancer properties of CLCE and its mechanism against lung cancer.

METHODS

Different extraction processes were performed and analyzed polyphenol content. The bioactives and essential oils present in curry leaves were identified through LC-MS/MS and GC-MS analysis. The cytotoxicity of microwave-assisted CLCE (MA-CLCE) was investigated through MTT and colony-forming assays. The DNA damage was observed by comet assay. The apoptotic mechanisms of MA-CLCE were investigated by estimating ROS production, depolarization of mitochondrial membrane potential (MMP), and apoptotic proteins. The glutathione assay estimated the antioxidant potential of MA-CLCE in normal cells.

RESULTS

Generally, conventional extraction methods require high temperatures, extra energy input, and time. Recently, green extraction processes are getting wider attention as alternative extraction methods. This study compared different extraction processes and found that the microwave-assisted extraction (MAE) method yields the highest polyphenols from curry leaves among other extraction processes with minimum processing. The MA-CLCE functions as an antioxidant under normal physiological conditions but pro-oxidant to cancer cells. MA-CLCE scavenges free radicals and enhances the intracellular GSH level in alveolar macrophages in situ. We found that MA-CLCE selectively inhibits cell proliferation and induces apoptosis in cancer cells by altering cellular redox status. MA-CLCE induces chromatin condensation and genotoxicity through ROS-induced depolarization of MMP. The depolarization of MMP causes the release of cytochrome c into the cytosol and activates the apoptotic pathway in lung cancer cells. However, pretreatment with ascorbic acid, an antioxidant, inhibits the MA-CLCE-induced apoptosis by reducing ROS production, which impedes mitochondrial membrane disruption, preventing BAX/BCL-2 expression alteration. Simultaneously, MA-CLCE downregulates the expression of survival signaling regulator PI3K/AKT, which modulates Nrf-2. MA-CLCE also diminishes intracellular antioxidant proficiency by suppressing Nrf-2 expression, followed by HO-1 expressions.

CONCLUSION

Among several extraction methods, MA-CLCE is rich in several bioactives, especially polyphenols, alkaloids, and essential oils. Here, we reported for the first time that MA-CLCE functions as a pro-oxidant to lung cancer cells and acts as an antioxidant to normal cells by regulating different cellular programs and signaling pathways. Therefore, it can be further developed as a promising phytomedicine against lung cancer.

Variation in the Main Health-Promoting Compounds and Antioxidant Activity of Different Edible Parts of Purple Flowering Stalks (Brassica campestris var. purpuraria) and Green Flowering Stalks (Brassica campestris var. campestris)

Purple flowering stalks and green flowering stalks of Brassica campestris are widely cultivated in the middle and upper reaches of the Yangtze River. Here, concentrations of the main health-promoting compounds and antioxidant capacity levels were characterized in different parts (leaves, peel, flesh, and inflorescences) of purple and green flowering stalks. There were significant differences in the concentrations of health-promoting compounds between the two variants; the concentrations of pigments, especially anthocyanidins, and gluconapin, were significantly higher in purple flowering stalks than in green flowering stalks, and the progoitrin content was significantly higher in green flowering stalks than in purple flowering stalks. The leaves were judged to be the most nutritional edible part because they had the highest concentrations of pigments, ascorbic acid, proanthocyanidins, flavonoids, and total phenolics. Antioxidant capacity was also highest in the leaves, and it was positively correlated with the concentration of health-promoting compounds. Purple flowering stalks and green flowering stalks were found to be rich in health-promoting compounds, especially glucosinolates. Overall, our findings indicate that consumption of the leaves and peel would provide the most health benefits. Some suggestions are provided regarding the processing and utilization of these edible components.

Immunomodulatory effect of metabolites from digested and fermented fractions from irradiated pineapple (Annanas comosus L.) snack-bars

Phenolic compounds (PC), can modulate the immune response. UV-C irradiation, commonly used as a minimal processing method in fresh-foods to reduce the microbial load, increase shelf-life, provide a minimal processing and facilitate the release of PC. This study aimed to evaluate the effect of intestinal (IF) and fermented (FF) fractions of non-irradiated (NIPB) and irradiated (IPB) pineapple snack-bars on the production of nitric oxide (NO), interleukin 6 (IL-6), cyclooxygenase 2 (COX-2), and tumor necrosis factor-alpha (TNF-α) in mice macrophages. IF of NIPB and IPB exerted an immunomodulatory effect by promoting the production of NO (26 pg/mL) in both treatments, COX-2 (438 and 399 pg/mL), and TNF-α (778 and 802 pg/mL) for NIPB and IPB respectively. The TNF-α increased in IF of NIPB and IPB approximately 371 %, and in FF, only increased 132 %. The NO production was not different between IF and FF. COX-2 production was higher in FF.

Ethanolic extract of Pyrus pashia buch ham ex. D. Don (Kainth): A bioaccessible source of polyphenols with anti-inflammatory activity in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Pyrus pashia Buch ham ex. D. Don (Kainth) fruit from the Himalayan region is traditionally consumed by native people in the form of decoctions for various clinical conditions including inflammatory diseases. However, scientific studies on the biofunctional properties of Kainth fruits are still scarce.

AIM OF THE STUDY

The study is aimed to investigate the anti-inflammatory effects of Kainth fruit extracts using in vitro and in vivo inflammation models.

MATERIAL AND METHODS

Free, esterified and bound fractions from the Kainth ethanolic extracts were prepared for determining the anti-inflammatory effect. The levels of 5-LOX and COX-2 were determined in vitro. The protein levels of cytokines (IL-6, TNF-α & IL-10) were quantitated by ELISA method in lipopolysaccharide-stimulated RAW macrophages. Also, the anti-inflammatory potential of the Kainth fruit extracts was determined using the carrageenan-induced mice paw edema model. The bioaccessibility of Kainth fruit extracts was measured using a simulated in vitro digestion system (salivary, gastric and intestinal).

RESULTS

The Kainth fruit extracts were partially purified to yield free, esterified and bound phenolics. Free and bound phenolics of Kainth fruits inhibited 5-Lipoxygenase, Cyclooxygenase-2 activities and pro-inflammatory cytokines (Interleukin-6 and tumour necrosis factor-α) expression in vitro. Also, oral administration of these extracts to the carrageenan-injected mice showed an anti-inflammatory effect by decreasing the pro-inflammatory cytokines and reducing the cellular infiltration in paw tissues. Also, both the extracts showed better bioavailability and bioaccessibility in in vitro and in vivo studies.

CONCLUSIONS

The results indicated that free and bound phenolics from Kainth fruits that are rich in catechin, epicatechin, arbutin and chlorogenic acid exhibited anti-inflammatory effects and could potentially be used to treat inflammatory diseases.

Effect of heat processing on phenolics and their possible transformation in low-sugar high-moisture (LSHM) fruit products from Kainth (Pyrus pashia Buch.-ham ex D. Don) fruit

LSHM fruit products were developed using 40% Kainth fruit juice (KJ40) and 10% pomace (KP10). The percentage of fruit juice and pomace was optimized based on the sensory analysis. The effect of heat processing on the nutritional and neutraceuticals parameters was studied. The product KJ40 was rich in free phenolics, while in KP10, it was bound phenolics. Both the products had good retention of phenolics, vitamins, minerals during processing and were microbiologically safe for up to six months. UPLC-ESI-HRMS was used for the identification and quantification of major phenolic compounds. Arbutin and catechin were the most stable phenolics during processing and storage. A slight change in catechin and chlorogenic acid contents was observed, which might be transformed or degraded. Tentatively, three unknown compounds were also identified using non-targeted analysis (Marker View Software, AB Sciex). Both products might offer health benefits as rich in phenolics and dietary fiber (≥5%).

Pterocarpus santalinus L. extract mitigates gamma radiation-inflicted derangements in BALB/c mice by Nrf2 upregulation

Plant-based natural extracts contain several nutrients and bioactive compounds, such as phenolics and flavonoids, that possess various health-promoting activities. This study investigated the effects of polyphenols from Pterocarpus santalinus hydroalcoholic extract (PSHE) against gamma radiation-induced derangements via the upregulation of Nrf2. Ultra High Performance Liquid Chromatography Coupled to High Resolution Mass Spectrometry (UHPLC-HRMS/MS) analysis was performed to identify the possible radioprotectors. In vivo and in vitro studies, namely Real-Time-PCR (RT-PCR) analysis, Reactive Oxygen Species (ROS) scavenging activity, lipid peroxidation and GSH levels, DNA damage and cell death studies, anti-inflammatory (Sandwich ELISA), immunomodulatory studies (antibody staining), and model free radical scavenging assays, were performed. Vanillic acid, protocatechuic acid, para-hydroxybenzoic acid, chlorogenic acid, TNF-α inhibitor (Eudesmin), isoflavone (Daidzein 7-o-glucoside), astragalin (Kaempferol 3-o-glycoside), and other polyphenols were identified in PSHE using UHPLC-HRMS/MS analysis. Prophylactic administration of PSHE (-1 h) rendered more than 33% survival in mice exposed to 8 Gy whole-body-irradiation with increased mice survival and recovery of bone marrow and spleen cellularity. Real-time RT-PCR analysis showed that PSHE treatment (50 µg/mL) upregulated Nrf2, HO-1, and GPX-1 in mice splenocytes. At 50 µg/mL, PSHE reduced ROSscavenging activity, mitochondrial and spleen membrane lipid peroxidation levels, DNA damage, and cell death, and increased GSH levels. At 10 µg/mL, PSHE treatment diminished the content of IL-6 and TNF-α. At 50 µg/mL, PSHE suppressed lymphocyte proliferation. These findings indicate that polyphenols of PSHE possess marked antioxidant, anti-inflammatory, and immunomodulatory capacities, which play important roles in the prevention of radiation damage.

Comprehensive Mass Spectrometric Analysis of Snake Fruit: Salak (Salacca zalacca)

Snake fruit (Salacca zalacca (Gaert.) Voss) is a fruit species traditionally cultivated in Indonesia and other Southeast Asian countries. The edible parts of the fruits contain a certain amount of total phenolic, flavonoid, and monoterpenoid compounds, proving them to be their perfect sources. The main goal of this work was to detect, quantify, and identify various phenolic compounds present in snake fruit pulp. Ultrahigh performance liquid chromatography coupled to a Q-Orbitrap tandem mass spectrometer was able to detect 19 phenolic compounds in the salak pulp, including 5 flavanols, 6 phenolic acids, 2 flavonols, 1 flavone, and also 5 presumably new phenolic compounds. Among the detected compounds, 11 were reported and quantified for the first time in salak pulp. Chlorogenic acid was by far the most predominant phenolic compound. The next relatively abundant compounds in snake fruit were epicatechin, isoquercetin, neochlorogenic acid, ferulic acid, gallic acid and procyanidine B2 (levels at ca 5–10 μg/g in MeOH extract), syringic acid, and caffeic acid (levels at ca 1 μg/g in H2O extract). A significant total phenolic content (257.17 μL/mL) and antioxidant activities (10.56 μM TE/g of fruit pulp) were determined. In conclusion, S. zalacca fruit has potential to serve as a natural source of phenolic compounds with antioxidative activities which may be associated with their health benefits.

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

Plum (Prunus Salicina Lindl) is a rich source of phenolic compounds. However, the bound phenolics and its bioaccessibility and antioxidant activity remain unclear. Hence, the purpose of this study was to determine: 1) phenolic profiles of plum, including both free and bound phenolic fractions, 2) bioaccessibility of phenolic compounds in plum during simulated gastrointestinal digestions, 3) their antioxidant properties. A total of 17 phenolic compounds were identified by UPLC-Q-Exactive Orbitrap/MS with most epicatechin, neochlorogenic acid and procyanidin B2 in the free phenolics fraction, while catechin and epicatechin was the main compounds in the bound phenolics fraction. After the gastrointestinal digestion phase, the most bioaccessible phenolics were quercetin-pentoside (61.64%), cyanidin-3-O-glucoside (43.26%), and naringenin-7-O-β-D-glucoside (42.04%). The antioxidant capacity of both undigested plum and its digested fractions showed a positive correlation with the total phenolics, and with specific individual phenolic compounds such as neochlorogenic acid, epicatechin and procyanidin B2 in undigested plum whereas catechin, neochlorogenic acid, and epicatechin in digested one. The results confirm that bound fraction of plum contribution to the total phenolic content must be taken into account in the assessment of the improving human health effects of plum.

Phenolic profiles and antioxidant activities of free, esterified and bound phenolic compounds in walnut kernel

The free, esterified and bound forms of 37 phenolic compounds (including hydroxybenzoic acid, hydroxycinnamic acids, flavanols, flavonols and flavones) from walnut kernel (Juglans regia L.) were investigated in this study. Results showed that the majority of walnut phenolics were presented in the free form (51.1%-68.1%), followed by bound (21.0%-38.0%) and esterified forms (9.7%-18.7%). Ellagic acid, gallic acid, ferulic acid, sinapic acid and caffeic acid were widely distributed in three forms. Differently, jeuglone, kaempferol, quercetin-7-o-β-d-glucoside and dihydroquercetin were only found in free phenolics. Among the three forms, free phenolics had the highest radical scavenging activity (IC₅₀: DPPH, 15.5 µg/ml; ABTS, 13.6 µg/ml). The correlation coefficients between the antioxidant activities of phenolics and their corresponding contents were 0.82-0.92. More soluble phenolics (free and esterified forms) could be extracted by acetone, while methanol was better at extracting insoluble bound phenolics.

The Bioavailability, Extraction, Biosynthesis and Distribution of Natural Dihydrochalcone: Phloridzin

Phloridzin is an important phytochemical which was first isolated from the bark of apple trees. It is a member of the dihydrochalcones and mainly distributed in the plants of the Malus genus, therefore, the extraction method of phloridzin was similar to those of other phenolic substances. High-speed countercurrent chromatography (HSCCC), resin adsorption technology and preparative high-performance liquid chromatography (HPLC) were used to separate and purify phloridzin. Many studies showed that phloridzin had multiple pharmacological effects, such as antidiabetic, anti-inflammatory, antihyperglycaemic, anticancer and antibacterial activities. Besides, the physiological activities of phloridzin are cardioprotective, neuroprotective, hepatoprotective, immunomodulatory, antiobesity, antioxidant and so on. The present review summarizes the biosynthesis, distribution, extraction and bioavailability of the natural compound phloridzin and discusses its applications in food and medicine.

Simultaneous determination of 49 amino acids, B vitamins, flavonoids, and phenolic acids in commonly consumed vegetables by ultra-performance liquid chromatography-tandem mass spectrometry

A sensitive and reliable method was developed and validated for the simultaneous determination of 49 amino acids, B vitamins, flavonoids, and phenolic acids based on a rapid metabolomic extraction procedure combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) in a single chromatographic run and applied in analysis of 26 commonly consumed vegetables. The chromatographic and sample preparation conditions were optimized, given the high diversity of the target analytes. Eight isotope-labeled standards were applied to validate the method in terms of recovery, linearity, matrix effects, precision, and sensitivity. Most recoveries in four vegetable matrices ranged from 65.0% to 105.3% with associated RSDs < 20%. Low LOQs ranged from 0.06 to 17 µg/kg. Linear calibration curves with different ranges were established with R² > 0.993. Among the 26 vegetables, purple cabbage, broccoli, and red lettuce were found to contain the highest concentrations of free amino acids, B vitamins, and phenolic compounds.

Lipidome, nutraceuticals and nutritional profiling of Pyrus pashia Buch.-ham ex D. Don (Kainth) seeds oil and its antioxidant potential

Kainth fruit, as traditional medicine, has been used in the Himalayan region for its health-promoting properties. However, the phytochemicals and lipidomes of Kainth Seed Oil (KSO) are still scarce. Here, we investigated the physicochemical characterization of KSO and its nutraceuticals, antioxidant potentials. Kainth seeds contain 19-20% oil rich in polyunsaturated fatty acids (PUFA, 82.22%), particularly linoleic acid (C18:2). Lipidome analysis of KSO using high-resolution mass spectrometry showed that trilinoleate (C54:6) was the dominant triacylglycerol (TAG) species. Further, the characteristics of PUFA-rich oil were validated by Fourier transforms infrared spectroscopy (FTIR) and Differential Scanning calorimetry (DSC). The nutraceuticals profiling of KSO depicted the presence of tocopherols (86.72 mg) and phytosterols (32.25 mg) in 100 g oil with significant antioxidant activity. The oil cake contained 19.09% protein and minerals and can be a source for dietary protein. Collectively these results suggest that KSO will be a suitable source for PUFA and nutraceuticals potential.

Insights into Arbutin Effects on Bone Cells: Towards the Development of Antioxidant Titanium Implants

Arbutin is a plant-derived glycosylated hydroquinone with antioxidant features, exploited to combat cell damage induced by oxidative stress. The latter hinders the osseointegration of bone prostheses, leading to implant failure. Little is known about arbutin antioxidant effects on human osteoblasts, therefore, this study explores the in vitro protective role of arbutin on osteoblast-like cells (Saos-2) and periosteum-derived progenitor cells (PDPCs). Interestingly, cells exposed to oxidative stress were protected by arbutin, which preserved cell viability and differentiation. Starting from these encouraging results, an antioxidant coating loaded with arbutin was electrosynthesized on titanium. Therefore, for the first time, a polyacrylate-based system was designed to release the effective concentration of arbutin in situ. The innovative coating was characterized from the physico-chemical and morphological point of view to achieve an optimized system, which was in vitro tested with cells. Morpho-functional evaluations highlighted the high viability and good compatibility of the arbutin-loaded coating, which also promoted the expression of PDPC differentiation markers, even under oxidative stress. These results agreed with the coatings’ in vitro antioxidant activity, which showed a powerful scavenging effect against DPPH radicals. Taken together, the obtained results open intriguing opportunities for the further development of natural bioactive coatings for orthopedic titanium implants.