Antioxidant and pancreatic lipase inhibitory effects of flavonoids from different citrus peel extracts: An in vitro study

Dietary Factors and Cognitive Function: with a Focus on Subjective Cognitive Decline

PURPOSE OF THE REVIEW

Age-related cognitive decline is an important global challenge. Substantial evidence suggests that diet may prevent or delay cognitive aging. This narrative review examines recent literature on how dietary factors influence cognitive function, with a focus on subjective cognitive decline (SCD).

RECENT FINDINGS

Higher intakes of flavonoids, carotenoids, and plant-based protein were associated with lower odds of SCD. Berries, citrus fruits and juices, carotenoid-rich and green leafy vegetables, and beans/legumes were among the foods with the strongest inverse associations with SCD. Healthy dietary patterns, such as the Mediterranean and MIND diet, may be beneficial for maintaining subjective cognitive function. Healthy choice of diet may play a role in lowering the risk of late-life SCD.

Modification of coconut insoluble dietary fiber by enzymatic extraction and high-pressure homogenization: physicochemical property changes and inhibitory effects on pancreatic lipase activity

In this study, coconut insoluble dietary fiber (CIDF) was modified by high-pressure homogenization (HPH), and the physicochemical properties and pancreatic lipase (PL) inhibitory activity were investigated. HPH diminished the particle size of CIDF (859.90 nm to 232.80 nm) and increased the total surface area and gap ratio. HPH enhanced the water and oil holding capacities of CIDF from 6.01 to 10.33 g/g and from 6.52 to 9.87 g/g, respectively. CIDF markedly inhibited PL activity by up to 72.51 % (p < 0.05), with the inhibition rate of PL was significantly higher in HPH-modified CIDF than in unmodified CIDF. The exposure of CIDF's hydroxyl groups due to the HPH treatment directly affected the degree of binding of CIDF to PL. CIDF reduces PL activity through hydrogen bonding and hydrophobic interactions with its aromatic amino acid residues.

Novel pancreatic lipase inhibitory peptides derived from lotus seed protein: isolation, identification, and the interaction mechanism

In this study, pancreatic lipase (PL) inhibitory peptides were identified from a lotus seed protein (LSP) hydrolysate and the potential mechanism was investigated. The LSP hydrolysate was isolated and purified, and six PL inhibitory peptides were screened; in particular, Phe-Leu-Leu (FLL) and Glu-Phe-Phe (EFF) exhibited the strongest inhibitory activity. Molecular docking results indicated that FLL and EFF interacted with residues around the PL active site through hydrogen bonding and hydrophobic interactions. The Lineweaver-Burk curve revealed that FLL acted as a mixed-type inhibitor, while EFF exhibited non-competitive inhibition of PL. Additionally, fluorescence spectroscopy, circular dichroism (CD), and ultraviolet-visible (UV-Vis) spectrometry analyses confirmed that FLL and EFF altered the microenvironment and secondary structure of PL by increasing the β-sheet content and reducing the α-helix content, thereby decreasing the catalytic activity of PL. Molecular dynamics simulation further confirmed that PL-peptide complexes exhibited a more stable state and compact structure. In summary, FLL and EFF could be used in the development of food supplements for obesity prevention.

Bioactive flavonoids metabolites in citrus species: their potential health benefits and medical potentials

Citrus flavonoids are naturally occurring phytochemicals widely present in the peels and pulps of citrus fruits. They exhibit a wide range of biological activities, including antioxidant, anti-inflammatory, hypoglycemic, lipid-lowering, antimicrobial, and gut-protective effects. These metabolites show great potential in improving metabolic syndromes such as diabetes, non-alcoholic fatty liver disease (NAFLD), and cardiovascular diseases. Additionally, citrus flavonoids have demonstrated significant effects in inhibiting pancreatic lipase activity, regulating lipid metabolism, and enhancing intestinal barrier function. Advances in extraction and purification techniques have further promoted their applications in the fields of food, medicine, and functional materials. This review systematically summarizes the types, bioactivities, and mechanisms of action of citrus flavonoids, providing scientific evidence for their research and development.

An innovative approach to improve the taste, quality, and shelf life of aronia berry juice by integrating food ingredient technology with high-pressure processing (HPP) technology

Aronia juice possesses multiple health benefits; however, unfavorable taste and storage instability limit its large-scale production and consumption. In this study, aronia juice was formulated with 2% (w/w) gum Arabic or 0.5% (w/w) egg white powder, treated with high-pressure processing (HPP) at 600 MPa for 5 min, and stored at 4°C for 12 months. A hedonic test (N = 60) was conducted, and the level of microorganisms, physicochemical properties, phenolic content, and antioxidant capacity during storage were evaluated. The results showed both formulations effectively reduced astringency, enhanced consumer liking, and improved physical and color stability of aronia juice. During storage, aerobic plate count, yeast counts, and mold counts remained below 1 log CFU/mL after HPP treatment. Only slight fluctuations were observed in pH, titratable acidity, °Brix, and °Brix: acid. Nonanthocyanin phenolic compounds and antioxidant capacity remained relatively stable. Overall, aronia juice formulated with gum Arabic or egg white powder and treated with HPP exhibited higher consumer acceptability, good storage stability, and an extended microbial shelf life at 4°C. These findings are valuable in meeting consumer demand for healthy fruit juices with an appealing taste while supporting the development of the aronia berry industry. PRACTICAL APPLICATION: This study presents an innovative approach to improve the taste, quality, and shelf life of aronia berry juice by integrating food ingredient technology with high-pressure processing technology. The technology also could be used for the commercial production of other high-polyphenol juices like aronia berry.

Polymethoxylated flavone variations and in vitro biological activities of locally cultivated Citrus varieties in China

Citrus peels are rich in polymethoxylated flavones (PMFs), which have beneficial health and pharmacological properties. In this study, the profiles, variations, and biological activities of PMFs in the peel extracts of 27 Citrus varieties (eight species) native to China were investigated. UPLC-QTOF-MS/MS analysis revealed that mandarin accumulated more diversity and higher detectable PMF contents. Wangcangzhoupigan (ZPG) possessed the highest antioxidant capacity. Gailiangcheng (GLC) and Bingtangcheng (BTC), sweet oranges showed excellent inhibitory effects against pancreatic lipase and α-glucosidase, respectively. Most citrus extracts effectively inhibited the production of ROS and pro-inflammatory cytokines, while increasing the accumulation of anti-inflammatory cytokines. In addition, Limeng (LM), Cupig-oushigan (GSG), and Yanxiwanlu (YXWL) showed anti-proliferative effects against DU145 and PC3 cancer cells. This study provides a comprehensive PMF profile and biological activities of various citrus species and will benefit future functional citrus breeding practices aimed at designing plants rich in total or specific PMFs for health benefits.

Simultaneous recycling of flavonone and polymethoxyflavonoids from Chenpi processing residue based on their complementary action on glycolipid lowering activity: Innovative combination use of yeast and aqueous two-phase system

This study aimed at recycling flavonoids with glycolipid lowering activity from Chenpi processing residue produced by essential oil extraction. The crude Chenpi flavonoids obtained by ethanol reflux mainly contained flavonone (hesperidin) and polymethoxyflavonoids (nobiletin, tangeretin, sinensetin, and isosinensetin), which complementally exerted strong glycolipid lowering activity as revealed by digestive enzyme inhibitory activity, molecular docking and network pharmacology. The reducing sugar and water-soluble impurities were efficiently removed by yeast fermentation and aqueous two-phase system (ATPS) extraction, respectively. The optimal combination use of yeast (2 % w/v, CN36) and ATPS formed by 22 % (w/w) (NH4)2SO4 and 25 % (w/w) ethanol improved flavonoid purity to 60.25 %, enriched flavonone and polymethoxyflavonoids by 6.69-fold, and enhanced digestive enzyme inhibitory activity, which was superior to the use of individual yeast or ATPS, unoptimized combination, macroporous resin (XAD-16), and ethyl acetate. This study was the first to develop a recyclable biophysical method for simultaneous enrichment of flavonone and polymethoxyflavonoids.

Effects of Chenpi (Citrus reticulata cv. Chachiensis) on serum antioxidant enzymes, inflammatory factors, and intestinal health in Beagle dogs

Ensuring companion animal welfare is a top priority for the pet industry and owners alike. The health of the pets can be directly and effectively improved through diet. Chenpi includes beneficial ingredients with proven anti-inflammatory, antioxidant, and immunomodulatory properties. The present investigation involved feeding snacks infused with Chenpi powder (CPP) to dogs for 42 days to examine the potential health benefits of CPP. The research evidenced a notable increase in serum superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activity in dogs, accompanied by a decrease in malondialdehyde (MDA), interleukin-8 (IL-8), and interferon-gamma (IFN-γ) level. Additionally, CPP increased fecal scores and significantly reduced fecal odors due to inhibition of 3-methylindole, hydrogen sulfide (H2S), and ammonia nitrogen (NH4 +-N), and also raised the levels of fecal secretory immunoglobulin A (SIgA). Analysis of the microbial composition via 16S rRNA sequencing showed that CPP increased Bacteroidota and decreased Firmicutes in the gut flora at the phylum level. Functional prediction study of microbial communities also showed that the CPP group enriched metabolic and genetic information processing pathways. In addition, there were significant correlations between serum indicators and several significantly altered microorganisms. These findings suggest that CPP can potentially enhance the overall health of dogs by reducing fecal odorants, enhancing antioxidant and immunological capabilities, and modulating intestinal flora. This study establishes a solid scientific foundation regarding the application of CPP in functional pet foods.

Integrated serum pharmacochemistry, pharmacokinetics, and network analysis to explore active components of BuShao Tiaozhi Capsule on hyperlipidemia

BuShao Tiaozhi Capsule (BSTZC), a novel drug in China, has been used to treat hyperlipidemia (HLP) in clinical practice for many years. Despite our previous studies suggesting that BSTZC can treat HLP, there is a lack of a rapid and systematic method to explore its active components. Therefore, in this study, we aimed to investigate the active components and mechanisms of BSTZC in treating HLP by integrating serum pharmacology, pharmacokinetics, network analysis, and experimental validation. We first established UPLC fingerprints, calibrated 23 common peaks, and identified 13 common peaks, and the similarity was greater than 0.99 for 10 batches. A total of nine metabolites from BSTZC were identified in serum and considered as PK markers. The pharmacokinetic parameters of the PK markers were compared between the control group and the model group through the pharmacokinetics study to determine the dynamic changes of representative components in rats. Compared with the control group, the Cmax and AUC0→t of OXY, IVT, IVL, and KPF-3-G were significantly higher (P< 0.05); the AUC0→∞ of OXY, PN, and IVT was significantly higher (P< 0.05); and the t1/2 of IVT, SA, and KPF-3-G was significantly different (P< 0.05). In vivo experiments showed that BSTZC and its active components could effectively alleviate lipid metabolism disorders and liver injury, with obvious lipid-lowering effects. Further studies showed that BSTZC alleviated HLP by inhibiting the PI3K/Akt signaling pathway, which was consistent with the results of the network analysis study. Our results revealed the active components and mechanisms of BSTZC in the treatment of HLP, which could provide useful information to guide the clinical application of BSTZC.

Avascular Necrosis in Renal Transplant Patients

OBJECTIVES

Kidney transplant recipients are at increased risk for avascular necrosis due to steroid use and accompanying comorbidities. Concerning risk factors, uncertainty still exists. We evaluated the clinical characteristics and risk factors of avascular necrosis in kidney transplant recipients.

MATERIALS AND METHODS

Symptomatic avascular necrosis was found by magnetic resonance imaging in 33 of 360 kidney transplant patients between 2005 and 2021. The patients' clinical characteristics, biochemical testing, and medications were evaluated.

RESULTS

We found the frequency of avascular necrosis to be 9.7% during the follow-up period. If the total steroid dosage used was more than 4 g in the first 3 months, the risk of developing avascular necrosis increased 4.08 times, and the presence of cytomegalovirus disease increased the risk by 4.03 times. Avascular necrosis was observed bilaterally in 60.6% of cases and at the femoral head in 66.7%. The frequency of avascular necrosis was highest in the first and second years posttransplant.

CONCLUSIONS

We found that avascular necrosis appears most frequently in the first 2 years after kidney transplant and the most important risk factors are cumulative steroid dose and cytomegalovirus disease. In the follow-up of kidney transplant patients, it is important to use low-dose steroid doses if possible. Of note, preventing the development of cytomegalovirus disease by screening and prophylaxis for cytomegalovirus is also important in reducing the development of avascular necrosis.

Targeted/untargeted metabolomics and antioxidant properties distinguish Citrus reticulata 'Chachi' from Citrus reticulata Blanco

Dried citrus peel (DCP), also called "Chen Pi", has edible and medicinal value. However, the specific differences among various sources remain unknown. Herein, we collected six DCP species, namely, one Citrus reticulata 'Chachi' (CZG) and five Citrus reticulata Blanco (CRB). Targeted high-performance liquid chromatography and untargeted ultra-high-performance liquid chromatography-tandem mass spectrometry were employed to comprehensively compare the phenolic compounds and metabolites in DCP. Interestingly, 13 different phenolic compounds were noted in DCP. The total phenolic compound content in all CRB samples (58.86-127.65 mg/g) was higher than that of CZG (39.47 mg/g). Untargeted metabolomic revealed 1495 compounds, with 115 differentially expressed metabolites for CRBs and CZG, particularly flavonoids (38), terpenoids (15), and phenolic acids and derivatives (9). Lastly, antioxidant assays revealed that all CRB samples exhibited higher antioxidant activities compared with CZG. Therefore, our study results provide a theoretical basis for the high-value utilization of citrus peels and their metabolites.

Exploration of the Mechanism of Guaijaverin in Inhibiting Pancreatic Lipase Based on Multispectral Method, Molecular Docking, and Oral Lipid Tolerance Test in Rats

This study aims to investigate the action mechanism of guaijaverin on pancreatic lipase from multiple perspectives and provide a theoretical basis for the search for new pancreatic lipase inhibitors. The inhibition of pancreatic lipase by guaijaverin was investigated through enzyme inhibition activity experiments, and the IC50 was calculated to determine the type of inhibition of guaijaverin. The mechanism of action was studied by measuring fluorescence, ultraviolet spectra, and circular dichroism. Molecular docking technology was used to explore the binding situation. In addition, in vivo oral lipid tolerance tests in rats were carried out to investigate the inhibitory effect of guaijaverin on pancreatic lipase. Guaijaverin inhibited pancreatic lipase up to 90.63%, confirming its excellent inhibitory ability. The inhibition type was noncompetitive inhibition in reversible inhibition. The multispectral experiments indicated that its quenching type was static quenching and guaijaverin changed the microenvironment and spatial conformation of pancreatic lipase. The molecular docking results showed that the minimum binding energy between the two compounds was -6.96 kcal/mol. In vivo experiments demonstrated that guaijaverin inhibits pancreatic lipase by reducing TG uptake in the body. Guaijaverin has excellent inhibitory effects on pancreatic lipase and has the potential to function as a pancreatic lipase inhibitor.

Recovery, Bioactivity, and Utilization of Bioactive Phenolic Compounds in Citrus Peel

Citrus peels are rich in bioactive phenolic compounds with various health effects including antioxidant, antiobesity, antiinflammatory, antihypertensive, antihypercholesterolemic, antimicrobial, antidiabetic, and anticarcinogenic activities. Both extractable and nonextractable phenolics are present in significant amounts in Citrus peel with diverse bioactivities. While extractable phenolics can be recovered from the fruit peels by conventional extraction methods, nonextractable phenolics remaining in the residues must be released from the cell matrix first by hydrolysis with acid, alkali, or enzymes. Novel processing technologies can help in improvement of extraction efficiency. Extreme process or medium conditions degrade phenolics and their bioactivity where encapsulation can be applied to improve their stability, solubility, and bioactivity. Citrus peel powder including ascorbic acid and dietary fiber besides phenolics or extracts therefrom can be used as functional food ingredients to extend shelf life and provide health benefits. In addition, phenolic extracts can be used as antioxidant and antimicrobial agents in active food packaging applications. Phenolic extracts have also a potential to be used as nutraceuticals and pharmaceuticals. In this review, phenolic compounds in different forms in Citrus peels, their recovery, bioactivity and possible applications for upcycling in the industry are presented.

Effectively Enhancing the Physiological Activity and Sensory Quality of Whole Calamondin Puree via Yeast Fermentation

To explore the feasibility of pure yeast fermentation in whole Calamondin puree (FWCP) for the utilization of the whole fruit, yeasts were isolated from naturally fermented Calamondin, and their fermentation characteristics were evaluated. The results indicated that all yeasts were able to ferment FWCP, reducing the sour taste by degrading citric acid, increasing the contents of nutrients (such as phenols and limonins) and volatile compounds, and enhancing the antioxidant activity and inhibition of α-glucosidase activity (p < 0.05). Among them, P. terricola QJJY1 and H. opuntiae QJJY14 exhibited stronger abilities to degrade organic acids, with P. terricola QJJY1 enhancing the antioxidant capacity by releasing phenolic compounds such as phloretin-3',5'-di-c-β-glucoside, vitexin-2″-O-rhamnoside, and isomargaritene. Moreover, H. opuntiae QJJY15 improved the contents of characteristic volatile compounds such as terpene hydrocarbons and higher alcohols. In total, 70 components were identified as differential metabolites based on their fold change in the metabolites, with 42 differential metabolites involved in 29 metabolic pathways across four strains. The main pathways related to phenol and flavor enrichment were flavonoid, flavone, and flavonol biosynthesis, monoterpenoid biosynthesis, and glyoxylate and dicarboxylate metabolism. Therefore, yeast fermentation is an effective method for utilizing whole Calamondin.

Excretion characteristics of main compounds of Yigong San in urine, feces, and bile of rats

Yigong San (YGS) is a traditional Chinese medicine formula used for pediatric anorexia, chronic atrophic gastritis, and irritable bowel syndrome. In this study, the excretion of eight main compounds, including liquiritin; isoliquiritin; hesperidin; ginsenosides Rb1, Re, and Rg1; and atractylenolides I and II, in rat urine, feces, and bile, was investigated by ultra-high performance liquid chromatography-tandem mass spectrometry. The results showed that the cumulative excretion rates of the compounds in rat urine, feces, and bile were 0.018-1.15%, 0.024-19.89%, and 0.0025-0.72%, respectively. Among the eight compounds detected, liquiritin was the richest in urine, and ginsenosides Re and Rg1 and atractylenolide I were mainly found in feces and bile. In summary, the main components of YGS are excreted via multiple approaches. Liquiritin is mainly through urine, whereas isoliquiritin; hesperidin; ginsenosides Rb1, Re, and Rg1; and atractylenolides I and II are mainly through feces. The excretion of these compounds in bile is usually positively correlated with that in feces. This study lays a foundation for further pharmacological research and application of YGS.

Research advances in citrus polyphenols: green extraction technologies, gut homeostasis regulation, and nano-targeted delivery system application

Citrus polyphenols can modulate gut microbiota and such bi-directional interaction that can yield metabolites such as short-chain fatty acids (SCFAs) to aid in gut homeostasis. Such interaction provides citrus polyphenols with powerful prebiotic potential, contributing to guts' health status and metabolic regulation. Citrus polyphenols encompass unique polymethoxy flavonoids imparting non-polar nature that improve their bioactivities and ability to penetrate the blood-brain barrier. Green extraction technology targeting recovery of these polyphenols has received increasing attention due to its advantages of high extraction yield, short extraction time, low solvent consumption, and environmental friendliness. However, the low bioavailability of citrus polyphenols limits their applications in extraction from citrus by-products. Meanwhile, nano-encapsulation technology may serve as a promising approach to improve citrus polyphenols' bioavailability. As citrus polyphenols encompass multiple hydroxyl groups, they are potential to interact with bio-macromolecules such as proteins and polysaccharides in nano-encapsulated systems that can improve their bioavailability. This multifaceted review provides a research basis for the green and efficient extraction techniques of citrus polyphenols, as well as integrated mechanisms for its anti-inflammation, alleviating metabolic syndrome, and regulating gut homeostasis, which is more capitalized upon using nano-delivery systems as discussed in that review to maximize their health and food applications.

Metabolic profile and bioactivity of the peel of Zhoupigan (Citrus reticulata cv. Manau Gan), a special citrus variety in China, based on GC-MS, UPLC-ESI-MS/MS analysis, and in vitro assay

Zhoupigan (Citrus reticulata cv. Manau Gan) is a local citrus variety in China. Its peel, known as Zangju peel (ZJP). The metabolic profile and bioactivity of ZJP have not been adequately studied, resulting in underutilization of ZJP and a serious waste of resources. In this study, GC-MS identified 46 components in ZJP, which defined ZJP's distinct aroma. Furthermore, UPLC-ESI-MS/MS detected 1506 metabolites in ZJP, and the differential metabolites were primarily involved in the biosynthesis of flavonoids and phenylacetone. Additionally, 56 key differential metabolites with metabolic pathways were identified. ZJP had significant antioxidant activity and the enzyme inhibitory activity ranking as pancreatic lipase (IC50 = 3.71 mg/mL) > α-glucosidase (IC50 = 6.28 mg/mL) > α-amylase (IC50 = 8.02 mg/mL). This study aimed to evaluate the potential of ZJP as natural antioxidant and functional food source and to serve as foundation for the further development of ZJP products with specific functional attributes.

Comparative Evaluation of Micellization and Cellular Uptake of β-Carotene Affected by Flavonoids

Based on in vitro digestion, micellar synthesis, and Caco-2 cell model, this study investigated the effects of typical flavonoids in citrus (naringenin, naringin, hesperetin, hesperidin, quercetin, and rutin) at different doses on the micellization and cellular uptake of β-carotene. In in vitro digestion, low-dose flavonoids enhanced β-carotene bioaccesssibility by regulating the stability and dispersibility of the intestinal medium, particularly quercetin, which significantly increased the bioaccessibility by 44.6% (p < 0.05). Furthermore, naringenin, hesperetin, hesperidin, and quercetin enhanced the micellar incorporation rate of β-carotene; however, naringin and rutin exhibited an opposite effect, particularly naringin, which significantly reduced it by 71.3% (p < 0.05). This phenomenon could be attributed to the high solubility of naringin and rutin in micelles, resulting in a competitive inhibitory effect on β-carotene. Besides, all treatments significantly enhanced β-carotene cellular uptake (p < 0.05) by promoting the expression of scavenger receptor class B type I and Niemann-Pick C1-Like 1.

Flavonoids with lipase inhibitory activity from lemon squeezing waste: isolation, multispectroscopic and in silico studies

BACKGROUND

Obesity is recognized as a lifestyle-related disease and the main risk factor for a series of pathological conditions, including cardiovascular diseases, hypertension and type 2 diabetes. Citrus limon is an important medicinal plant, and its fruits are rich in flavonoids investigated for their potential in managing obesity. In the present work, a green extraction applied to lemon squeezing waste (LSW) was optimized to recover pancreatic lipase (PL) inhibitors.

RESULTS

The microwave-assisted procedure yielded an extract with higher lipase inhibitory activity than those obtained by maceration and ultrasound. The main compounds present in the extract were identified by high-performance liquid chromatographic-mass spectrometric analysis, and hesperidin, eriocitrin and 4'-methyllucenin II were isolated. The three compounds were evaluated for in vitro PL inhibitory activity, and 4'-methyllucenin II resulted in the most promising inhibitor (IC50 = 12.1 μmol L-1; Ki = 62.2 μmol L-1). Multispectroscopic approaches suggested the three flavonoids act as competitive inhibitors and the binding studies indicated a greater interaction between PL and 4'-methyllucenin II. Docking analysis indicated the significant interactions of the three flavonoids with the PL catalytic site.

CONCLUSION

The present work highlights flavonoid glycosides as promising PL inhibitors and proposes LSW as a safe ingredient for the preparation of food supplements for managing obesity. © 2024 Society of Chemical Industry.

Discovery of Curcuminoids as Pancreatic Lipase Inhibitors from Medicine-and-Food Homology Plants

Researchers are increasingly interested in discovering new pancreatic lipase inhibitors as anti-obesity ingredients. Medicine-and-food homology plants contain a diverse set of natural bioactive compounds with promising development potential. This study screened and identified potent pancreatic lipase inhibitors from 20 commonly consumed medicine-and-food homology plants using affinity ultrafiltration combined with spectroscopy and docking simulations. The results showed that turmeric exhibited the highest pancreatic lipase-inhibitory activity, and curcumin, demethoxycurcumin, and bisdemethoxycurcumin were discovered to be potent pancreatic lipase inhibitors within the turmeric extract, with IC50 values of 0.52 ± 0.04, 1.12 ± 0.05, and 3.30 ± 0.08 mg/mL, respectively. In addition, the enzymatic kinetics analyses demonstrated that the inhibition type of the three curcuminoids was the reversible competitive model, and curcumin exhibited a higher binding affinity and greater impact on the secondary structure of pancreatic lipase than found with demethoxycurcumin or bisdemethoxycurcumin, as observed through fluorescence spectroscopy and circular dichroism. Furthermore, docking simulations supported the above experimental findings, and revealed that the three curcuminoids might interact with amino acid residues in the binding pocket of pancreatic lipase through non-covalent actions, such as hydrogen bonding and π-π stacking, thereby inhibiting the pancreatic lipase. Collectively, these findings suggest that the bioactive compounds of turmeric, in particular curcumin, can be promising dietary pancreatic lipase inhibitors for the prevention and management of obesity.

Discovery of baicalein derivatives as novel inhibitors against human pancreatic lipase: Structure-activity relationships and inhibitory mechanisms

Human pancreatic lipase (hPL) is a vital digestive enzyme responsible for breaking down dietary fats in humans, inhibiting hPL is a feasible strategy for preventing and treating obesity. This study aims to investigate the structure-activity relationships (SARs) of flavonoids as hPL inhibitors, and to find potent hPL inhibitors from natural and synthetic flavonoids. In this work, the anti-hPL effects of forty-nine structurally diverse naturally occurring flavonoids were assessed and the SARs were summarized. The results demonstrated that the pyrogallol group on the A ring was a key moiety for hPL inhibition. Subsequently, a series of baicalein derivatives were synthesized, while 4'-amino baicalein (ABA) and 4'-pyrrolidine baicalein (PBA) were identified as novel potent hPL inhibitors (IC50 < 1 μM). Further investigations showed that scutellarein, ABA and PBA potently inhibited hPL in a non-competitive manner (Ki < 1 μM). Among all tested flavonoids, PBA showed the most potent anti-hPL effect in vitro, while this agent also exhibited favorable safety profiles, unique tissue distribution (high exposure level to intestinal system but low exposure levels to deep organs) and impressive in vivo effects for lowering blood triglyceride levels in mice. Collectively, this work uncovers the SARs of flavonoids against hPL, while a newly synthetic flavonoid (PBA) emerges as a potent hPL inhibitor with favorable safety profiles and impressive anti-hPL effects in vivo.

Characterisation of pancreatic lipase inhibitors from Brassica rapa L. ssp. chinensis

Obesity has become a significant global health concern, affecting millions of people worldwide. One well-studied approach to identifying potential anti-obesity agents is the inhibition of pancreatic lipase (PL), an enzyme responsible for dietary fat digestion. This study investigated the inhibitory effects and mechanisms of galactolipid monogalactosyldiacylglycerol (MGDG), that was extracted from Brassica rapa ssp. chinensis on PL. Five different MGDG compounds were isolated and the results showed that compounds containing shorter fatty acid side chains and a higher degree of unsaturated bonds exhibit a greater inhibition effect on PL. Interestingly, both the kinetic study and the molecular docking prediction revealed a non-competitive inhibition of MGDG. Furthermore, the in vitro digestion model also showed that the consumption of MGDG extract with salad dressing was effective in delaying enzymatic fat digestion in a dose-dependent manner. These results suggest that MGDG from Brassica rapa ssp. chinensis may be a promising candidate for developing novel anti-obesity therapies.

Health-Promoting Potential of Mandarin Pomace Extracts Enriched with Phenolic Compounds

The aim of this work was to assess the effect of in vitro human digestion on the chemical composition (carbohydrates and phenolic compounds) and bioactivity of hydro-alcoholic-acid pomace extracts from two mandarin varieties (Clemenule and Ortanique) by measuring their antioxidant, antidiabetic, anti-glycative, hypolipidemic, and anti-inflammatory properties. The phenolic compound profile showed that nobiletin was the main flavonoid found in the extracts and digests of Clemenule pomace and extract, while isosinensetin/sinensetin/tangeretin were the ones in the Ortanique samples. The digests of Clemenule and Ortanique extracts showed Folin reaction values of 9.74 and 9.20 mg gallic acid equivalents (GAE)/g of sample, ABTS values of 83.2 and 91.7 µmol Trolox equivalents (TE)/g of sample, and ORAC-FL values of 142.8 and 891.6 µmol TE/g of sample, respectively. Extracts (50-500 µg/mL) inhibited intracellular reactive oxygen species (ROS) formation in CCD-18Co cells under physiological and oxidative-induced conditions. Clemenule and Ortanique extract digests showed IC50 values of 13.50 and 11.07 mg/mL for α-glucosidase, 28.79 and 69.64 mg/mL for α-amylase, and 16.50 and 12.77 mg/mL for AGEs, and 2.259 ± 0.267 and 0.713 ± 0.065 mg/mL for pancreatic lipase inhibition, respectively. Ortanique extract (250-1000 µg/mL) inhibited the production of nitric oxide in RAW264.7 macrophages under inflammation-induced conditions, and intracellular ROS formation. In conclusion, altogether, the results supported the potential of mandarin extracts to be used as health promoters by reducing the risk of non-communicable chronic diseases.

A narrative review on the mechanism of natural flavonoids in improving glucolipid metabolism disorders

Glucolipid metabolism disorder (GLMD) is a complex chronic disease characterized by glucose and lipid metabolism disorders with a complex and diverse etiology and rapidly increasing incidence. Many studies have identified the role of flavonoids in ameliorating GLMD, with mechanisms related to peroxisome proliferator-activated receptors, nuclear factor kappa-B, AMP-activated protein kinase, nuclear factor (erythroid-derived 2)-like 2, glucose transporter type 4, and phosphatidylinositol-3-kinase/protein kinase B pathway. However, a comprehensive summary of the flavonoid effects on GLMD is lacking. This study reviewed the roles and mechanisms of natural flavonoids with different structures in the treatment of GLMD reported globally in the past 5 years and provides a reference for developing flavonoids as drugs for treating GLMD.

Effects of different addition levels of CHM-JM113 on growth performance, antioxidant capacity, organ index, and intestinal health of AA broilers

The purpose of the present study was to investigate the effects of different levels of a Chinese herbal medicine formulation combined with JM113 (CHM-JM113) on growth performance, antioxidant capacity, organ index, and intestinal health of AA broilers. The AA broiler chicks were randomly allocated to 5 treatments as follows: a basic diet for the control group, the basic diet supplemented with 0.25% CHM-JM113, 0.5% CHM-JM113, 1% CHM-JM113 and 2% CHM-JM113 for the treatment group, respectively. The results showed that the addition of CHM-JM113 to the diet significantly reduced the mortality (p < 0.01) and improved the European Broiler Index (EBI) (p < 0.05), whereas it had no significance on growth performance of AA broilers (p > 0.05). Comparing the control group, 0.5 and 1% CHM-JM113 group significantly improved the organ index of liver, spleen and bursa (p < 0.05). In terms of intestinal morphology and structure, the addition of different levels of CHM-JM113 increased VH and VH/CD ratio, decreased CD in the small intestine compared to the control group, with 1 and 2% of the additive dose being more effective (p < 0.05). Chinese herbal medicine and probiotics as natural antioxidants also significantly increased the content of SOD in serum of 21-day-old broilers (p < 0.01), and significantly decreased the content of MDA in serum (p < 0.01). At 42 days of age, the addition of 1 and 2% CHM-JM113 significantly increased the content of SOD (p < 0.01) and significantly decreased the content of MDA in the organism (p < 0.01), accompanied by a significant increase in T-AOC and CAT content. In the study of the effect of CHM-JM113 on intestinal immunity, compared with the control group, we found that 1% or 2% CHM-JM113 had a better effect on the expression of occludin and claudin-1 in the intestinal segments of broilers (p < 0.05). For the expression of GATA-3, 0.5% CHM-JM113 may have a better effect (p < 0.05). CHM-JM113 may be used as an antibiotic alternative in broiler production.

Lemon Flavonoid Extract Eriomin Improves Pro/Antioxidant Status and Interferes with Cholesterol Metabolism without Affecting Serum Cholesterol Levels in Aged Rats

This study aimed to assess the antioxidant capacity of lemon flavonoid extract Eriomin® (LE) and its impact on cholesterol metabolism in the context of healthy aging. We orally treated 24-month-old male Wistar rats with an LE (40 mg/kg) suspended in 0.3 mL of sunflower oil. At the same time, control groups received an equal volume of sunflower oil (CON) or remained untreated (ICON) daily for 4 weeks. We examined LE's effects on superoxide dismutase and catalase- and glutathione-related enzyme activities, the concentration of lipid peroxides and protein carbonyls, total oxidant status (TOS) and antioxidant status (TAS), and oxidative stress index (OSI) in the liver, jejunum, and ileum. We also measured total cholesterol, its biosynthetic precursors (lanosterol, lathosterol, desmosterol), its degradation products (bile acid precursors) in the serum, liver, jejunum, and ileum, and serum phytosterols (intestinal absorption markers). LE reduced TOS, TAS, and OSI (p < 0.05) compared with control values, indicating its consistent antioxidant action in all examined organs. LE lowered hepatic desmosterol (p < 0.05) while also reducing 7α- and 24-hydroxycholesterol levels in the liver and ileum (p < 0.01). Serum cholesterol, hepatic gene expression, and the immunostaining intensity of CYP7A1 were unchanged. In conclusion, LE exerted non-enzymatic antioxidant effects and reduced cholesterol degradation, reducing its biosynthesis products, thereby maintaining serum cholesterol levels.

Inquiry lipaseoring the mechanism of pancreatic lipase inhibition by isovitexin based on multispectral method and enzyme inhibition assay

Isovitexin is a main natural flavonoid component in various plants. Currently, the inhibitory effect of isovitexin on pancreatic lipase (PL) and its mechanism have not been elucidated yet. In the present study, we investigated the inhibitory effect of isovitexin on PL, as well as its interaction mechanism, using enzyme inhibition methods, spectroscopic analysis, and molecular simulations. Results showed that isovitexin possessed significant PL inhibitory activity, with IC50 values of 0.26 ± 0.02 mM. The interaction between isovitexin and PL was dominated by static quenching, and mainly through hydrogen bonding and hydrophobic interaction forces. Analysis of fluorescence spectroscopy confirmed that isovitexin binding altered the conformation of the PL. Circular dichroism (CD) spectrum indicated that isovitexin altered the secondary structure of PL by decreasing the α-helix content and increasing the β-fold content. Molecular simulations further characterize the conformational changes produced by the interaction between isovitexin with PL. The performed study may provide a new insight into the inhibitory mechanism of isovitexin as a novel PL inhibitor.

Total Content and Composition of Phenolic Compounds from Filipendula Genus Plants and Their Potential Health-Promoting Properties

This current article was dedicated to the determination of the composition of phenolic compounds in extracts of four species of the genus Filipendula in order to establish a connection between the composition of polyphenols and biological effects. A chemical analysis revealed that the composition of the extracts studied depended both on the plant species and its part (leaf or flower) and on the extractant used. All four species of Filipendula were rich sources of phenolic compounds and contained hydrolyzable tannins, condensed tannins, phenolic acids and their derivatives, and flavonoids. The activities included data on those that are most important for creating functional foods with Filipendula plant components: the influence on blood coagulation measured by prothrombin and activated partial thromboplastin time, and on the activity of the digestive enzymes (pancreatic amylase and lipase). It was established that plant species, their parts, and extraction methods contribute meaningfully to biological activity. The most prominent result is as follows: the plant organ determines the selective inhibition of either amylase or lipase; thus, the anticoagulant activities of F. camtschatica and F. stepposa hold promise for health-promoting food formulations associated with general metabolic disorders.

Influence of industrial blanching, cutting, and freezing treatments on in vitro gastrointestinal digestion stability of orange (Citrus sinensis L.) and lemon (Citrus limon L.) peel polyphenols

BACKGROUND

Citrus peels, which are often discarded as waste in the food-processing industry, are rich sources of polyphenols. The aim of the current study was to investigate the influence of an industrial freezing process along with blanching and cutting pretreatments on the in vitro gastrointestinal digestion stability of orange (Citrus sinensis L.) and lemon (Citrus limon L.) peel polyphenols. The major polyphenols were identified and quantified with ultra-performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI-MS/MS) and high performance liquid chromatography-photodiode array detector (HPLC-PDA), respectively.

RESULTS

The results revealed that hesperidin and chlorogenic acid were the predominant flavonoid and phenolic acids in orange peels whereas, for lemon peels, eriocitrin and caffeic acid were the dominant flavonoid and phenolic acids, respectively. Blanching pretreatment enhanced the levels of major flavonoids in orange and lemon peels (by 39-82% and 54-146%, respectively) (P < 0.05) after in vitro gastrointestinal digestion. On the other hand, the application of cutting treatment after blanching significantly reduced the levels of flavonoids (23-62%) (P < 0.05); however, there was no statistically significant difference between the phenolic acid levels of cut and uncut citrus peels. Overall, the bioaccessibility of individual flavonoids and phenolic acids from frozen orange peels was generally slightly lower than that of untreated peels (9-34% and 9-49%, respectively). Nevertheless, frozen lemon peels contained higher bioaccessible flavonoids and phenolic acids in comparison with untreated peels (40-172% and 32-98%, respectively).

CONCLUSION

These results suggest that industrial freezing steps could largely preserve the bioaccessibility of polyphenols in orange and lemon peels. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Mandarin peel ethanolic extract attenuates diclofenac sodium induced hepatorenal toxicity in rats by mitigating oxidative stress and inflammation

Nonsteroidal anti-inflammatory drugs (NSAIDs) constitute approximately one-third of the global pharmaceutical market and are the first drugs of choice when treating fever and pain. Furthermore, among NSAIDs, the use of diclofenac sodium (DS) is preferred as it is a strong inhibitor of cyclooxygenase enzyme. However, despite its strong efficacy, DS is known for its potential to cause hepatorenal damage. Currently, to mitigate the adverse effects of certain drugs, medically effective agricultural products are often preferred as they are inexpensive, effective and safe. One such agricultural product-mandarin-is noteworthy for its high phenolic contents. The purpose of the present study was to assess the efficacy of mandarin peel ethanolic extract (MPEE) in protecting against hepatorenal damage induced by DS. Four groups (six/group) of adult male albino rats received oral administration of physiological saline (control group), DS (10 mg/kg body weight), MPEE (200 mg/kg body weight), and DS + MPEE for 7 days. Rats in the DS group showed increased serum levels of ALT, AST, ALP, BUN, CRE, and UA. Furthermore, the hepatic and renal tissue levels of MDA, TNF-α and IL-1β increased, whereas those of GSH, SOD, GP-x and IL-10 decreased (p < 0.05). Investigation of MPEE in terms of its effects on biochemical, oxidative and inflammatory parameters, it exerted protective and healing effects. Therefore, MPEE can be used to ameliorate DS-induced hepatorenal damage.

Selenizing chitooligosaccharide with site-selective modification to alleviate acute liver injury in vivo

Two selenized chitooligosaccharide (O-Se-COS and N,O-Se-COS) with different sites modification were synthesized to alleviate liver injury in vivo. Comparing to traditional COS, both selenized COS exhibited enhanced reducibility as well as antioxidant capacity in vitro. Furthermore, O-Se-COS demonstrated superior efficacy in reducing intracellular reactive oxygen species (ROS) and mitochondrial damage compared to N,O-Se-COS as its enhanced cellular uptake by the positive/negative charge interactions. Two mechanisms were proposed to explained these results: one is to enhance the enzymatic activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), which effectively scavenge free radicals; the other is to down-regulate intracellular cytochrome P450 (CYP2E1) levels, inhibiting carbon tetrachloride (CCl4)-induced peroxidation damage. In vivo studies further demonstrated the effective alleviation of CCl4-induced liver injury by selenized COS, with therapeutic efficacy observed in the following order: O-Se-COS > N,O-Se-COS > COS. Finally, hemolysis and histological tests confirmed the biosafety of both selenized COS. Taken together, these finding demonstrated that selenium has the potential to improve the biological activity of COS, and precise selenylation was more conducive to achieving the synergistic effect where 1 + 1>2.

Antioxidant and anti-inflammatory activity through inhibition of NF-κB and sEH of some citrus peel and phytoconstituent characteristics

In Indonesia, there are many types of citrus where parts of the fruit, leaves, and peel can be utilized as food, drinks, spices, and medicine. This research aims to determine the phytochemical characteristics, antioxidant activities, and anti-inflammatory activity through inhibition of NF-κB and sEH, and the main phytoconstituents of three types of citrus fruits that are commonly used as herbs in Indonesia. The flesh and peel of Citrus amblycarpa/CAm, C. aurantiifolia/CAu, and C. hystrix/CH were extracted by Ultrasound-Assisted Extraction (UAE) with 70 % ethanol and then concentrated. All extracts were tested for total flavonoid content (TFC), total polyphenolic content (TPC), chemical constituents using LCMS, and DPPH radical scavenging activity. Molecular docking tests of 33 compounds containing CAm, CAu, and CH fruit peels from the literature study against NF-κB (Nuclear Factor Kappa Beta) and sEH (Soluble Epoxide Hydrolase) were also conducted. The TFC in fruit peels was 13.47-17.34 mg QE/g extract, and in flesh was 1.35-2.51 mg QE/g extract. The TPC in fruit peels was 4.28-6.3 mg GAE/g extract, and in flesh was 0.85-2.09 mg GAE/g extract. The IC50 values of antioxidant activity on fruit peel were 74.01-168.54 µg/mL; and flesh 185.62-2669 µg/mL. CAu peels provided the highest antioxidant activity and polyphenol content. The LC-MS/MS test on citrus peels shows the main chemical compounds: naringin (C27H32O14), naringenin (C15H12O5), hesperidin (C28H34O15), and hesperitin (C16H14O6). Molecular docking shows that naringin and neohesperidin predicted inhibit NF-κB, and hesperidin, neohesperidin, narirutin, naringin, apigenin, kaempferol, quercetin, rutin, eriocitrin, sinensetin, and vitamin A predicted can inhibit sEH enzyme. All citrus peel has stronger antioxidant activity and more flavonoids and phenolics than the flesh. Naringin and neohesperidin can inhibit NF-κB and sEH enzymes. The main flavonoid contents of the citrus peels and presumed to have activity are hesperidin and naringin. These flavonoids and their glycosides can be used as marker phytoconstituents in the quality assurance of pharmaceutical products.

Antioxidative, Metabolic and Vascular Medicinal Potentials of Natural Products in the Non-Edible Wastes of Fruits Belonging to the Citrus and Prunus Genera: A Review

Diabetes mellitus and related metabolic and vascular impairments are notable health problems. Fruits and vegetables contain phenolics that are beneficial to metabolic and oxidative health and useful in preventing associated disease. Scientific evidence has shown that some bioactive phenolics are more abundant in the non-edible parts (especially the peels) of many fruits than in their respective edible tissues. Fruits belonging to the Citrus and Prunus genera are commonly consumed worldwide, including in South Africa, and their non-edible wastes (peel and seed) have been shown to have antioxidative, metabolic and vascular pharmacological potentials and medicinal phytochemistry. It is therefore imperative to evaluate the pharmacological actions and phytochemical properties of the non-edible wastes of these fruits and understand how they could potentially be of medicinal relevance in oxidative, metabolic and vascular diseases, including diabetes, oxidative stress, obesity, hypertension and related cardiovascular impairments. In the absence of a previous review that has concomitantly presented the medicinal potentials of fruits wastes from both genera, this review presents a critical analysis of previous and recent perspectives on the medicinal potential of the non-edible wastes from the selected Citrus and Prunus fruits in metabolic, vascular and oxidative health. This review further exposes the medicinal phytochemistry, while elucidating the underlying mechanisms through the fruit wastes potentiates their therapeutic effects. A literature search was carried out on "PubMed" to identify peer-reviewed published (mostly 2015 and beyond) studies reporting the antidiabetic, antioxidative, antihypertensive, anti-hyperlipidemic and anti-inflammatory properties of the non-edible parts of the selected fruits. The data of the selected studies were analyzed to understand the bioactive mechanisms, bioactive principles and toxicological profiles. The wastes (seed and peel) of the selected fruits had antioxidant, anti-obesogenic, antihypertensive, anti-inflammatory, antidiabetic and tissue protective potentials. Some phenolic acids and terpenes, as well as flavonoids and glycosides such as narirutin, nobiletin, hesperidin, naringin, naringenin, quercetin, rutin, diosmin, etc., were the possible bioactive principles. The peel and seed of the selected fruits belonging to the Citrus and Prunus genera are potential sources of bioactive compounds that could be of medicinal relevance for improving oxidative, metabolic and vascular health. However, there is a need for appropriate toxicological studies.

Chemical Constituents and α-Glucosidase Inhibitory, Antioxidant and Hepatoprotective Activities of Ampelopsis grossedentata

Ampelopsis grossedentata is a valuable medicinal and edible plant, which is often used as a traditional tea by the Tujia people in China. A. grossedentata has numerous biological activities and is now widely used in the pharmaceutical and food industries. In this study, two new flavonoids (1-2) and seventeen known compounds (3-19) were isolated and identified from the dried stems and leaves of A. grossedentata. These isolated compounds were characterized by various spectroscopic data including mass spectrometry and nuclear magnetic resonance spectroscopy. All isolates were assessed for their α-glucosidase inhibitory, antioxidant, and hepatoprotective activities, and their structure-activity relationships were further discussed. The results indicated that compound 1 exhibited effective inhibitory activity against α-glucosidase, with an IC50 value of 0.21 μM. In addition, compounds 1-2 demonstrated not only potent antioxidant activities but also superior hepatoprotective properties. The findings of this study could serve as a reference for the development of A. grossedentata-derived products or drugs aimed at realizing their antidiabetic, antioxidant, and hepatoprotective functions.

Soluble polysaccharides decrease inhibitory activity of banana condensed tannins against porcine pancreatic lipase

The inhibition of soluble polysaccharides (SPs) (arabic gum, dextran and pectin from citrus) on the binding between banana condensed tannins (BCTs) and pancreatic lipase (PL) was studied from variant aspects. Molecular docking simulations predicted that BCTs strongly bound SPs and PL through non-covalent interactions. The experimental results showed that SPs reduced the inhibition of BCTs on PL, and the IC₅₀ value increased. However, the addition of SPs did not change the inhibitory type of BCTs on PL, which all were non-competitive inhibition. BCTs quenched PL fluorescence through static quenching mechanism and changed the secondary structure of PL. The addition of SPs alleviated the trending. The effect of SPs on the binding of BCTs-PL was mainly due to the strong non-covalent interaction between SPs and BCTs. This study emphasized that attention should be paid to the counteracting effects of polysaccharides and polyphenols in dietary intake to maximize their respective roles.

Research Progress of Immunomodulation on Anti-COVID-19 and the Effective Components from Traditional Chinese Medicine

SARS-CoV-2 has posed a threat to the health of people around the world because of its strong transmission and high virulence. Currently, there is no specific medicine for the treatment of COVID-19. However, for a wide variety of medicines used to treat COVID-19, traditional Chinese medicine (TCM) plays a major role. In this paper, the effective treatment of COVID-19 using TCM was consulted first, and several Chinese medicines that were frequently used apart from their huge role in treating it were found. Then, when exploring the active ingredients of these herbs, it was discovered that most of them contained flavonoids. Therefore, the structure and function of the potential active substances of flavonoids, including flavonols, flavonoids, and flavanes, respectively, are discussed in this paper. According to the screening data, these flavonoids can bind to the key proteins of SARS-CoV-2, 3CLpro, PLpro, and RdRp, respectively, or block the interface between the viral spike protein and ACE2 receptor, which could inhibit the proliferation of coronavirus and prevent the virus from entering human cells. Besides, the effects of flavonoids on the human body systems are expounded on in this paper, including the respiratory system, digestive system, and immune system, respectively. Normally, flavonoids boost the body's immune system. However, they can suppress the immune system when over immunized. Ultimately, this study hopes to provide a reference for the clinical drug treatment of COVID-19 patients, and more TCM can be put into the market accordingly, which is expected to promote the development of TCM on the international stage.

Antioxidants from different citrus peels provide protection against cancer

Cancer is one of the leading causes of death. Despite significant advancements in the discovery of medications for the treatment of cancer, these drugs are hindered by applicability and efficacy issues and frequently exhibit major side effects that can further impair patients 'quality of life. Therefore, the development of therapeutically sound anti-cancer medicines derived from natural products has gained prominence in the field of functional foods. Some of these compounds have shown efficacy in the prevention and treatment of cancer as well as low toxicity. Additionally, many recent studies have explored the recycling of agro-industrial waste to create bioactive chemicals. Citrus peels are produced in vast quantities in the food processing sector; due to their abundance of flavonoids, they may be inexpensive sources of protection against several cancers. Citrus is a common type of fruit that contains a variety of nutrients. In particular, the antioxidant chemicals found in citrus peel have been identified as potential cancer-fighting agents. Antioxidant substances such as flavonoids prevent the development of cancer by inhibiting the metastatic cascade, decreasing the mobility of cancer cells in the circulatory system, promoting apoptosis, and suppressing angiogenesis. To explore the most effective uses of citrus peel-derived antioxidants, this review presents background information, an overview of the role of citrus antioxidants in cancer therapy, and a discussion of the key underlying molecular mechanisms.

Classification of Pericarpium Citri Reticulatae (Chenpi) age using surface-enhanced Raman spectroscopy

Pericarpium Citri Reticulatae (PCR) is used in food and medical herbal formula, and its quality is determined by its age. Raman spectroscopy is a laser technology for molecular fingerprinting. The feasibility of using surface-enhanced Raman spectroscopy (SERS) to determine the PCR age was investigated. The Raman peaks were acquired using a Raman spectrometer with a 785 nm diode laser and were analyzed using principal component analysis (PCA) followed by linear discriminant analysis (PCA-LDA). There were six major peaks at 600, 730, 990, 1370, 1607, and 1742 cm^-1 in the SERS spectra, and their intensity, especially the peak at 1607 cm^-1, was inversely correlated with the PCR age. The different ages of PCR could be correctly classified with over 90 % accuracy by using PCA-LDA based on the SERS spectra. In conclusion, a Raman spectrometer may be used as a novel method to identify the age of PCR products.

Role of flavonoids in controlling obesity: molecular targets and mechanisms

Obesity presents a major health challenge that increases the risk of several non-communicable illnesses, such as but not limited to diabetes, hypertension, cardiovascular diseases, musculoskeletal and neurological disorders, sleep disorders, and cancers. Accounting for nearly 8% of global deaths (4.7 million) in 2017, obesity leads to diminishing quality of life and a higher premature mortality rate among affected individuals. Although essentially dubbed as a modifiable and preventable health concern, prevention, and treatment strategies against obesity, such as calorie intake restriction and increasing calorie burning, have gained little long-term success. In this manuscript, we detail the pathophysiology of obesity as a multifactorial, oxidative stress-dependent inflammatory disease. Current anti-obesity treatment strategies, and the effect of flavonoid-based therapeutic interventions on digestion and absorption, macronutrient metabolism, inflammation and oxidative stress and gut microbiota has been evaluated. The use of several naturally occurring flavonoids to prevent and treat obesity with a long-term efficacy, is also described.

Comparative study on secondary metabolites from different citrus varieties in the production area of Zhejiang

To investigate the distribution pattern of bioactive components and their correlations between citrus varieties, we thoroughly analyzed secondary metabolites (including flavonoids, phenolic acids, carotenoids, and limonoids) in the peel and pulp of 11 citrus varieties from the production area of Zhejiang. Citrus peels accumulated metabolites far more than the pulp, and the accumulation varied significantly between species. Flavonoids were the most abundant compounds, followed by phenolic acids, with carotenoids and limonoids being far less abundant than the first two, but limonoids were more abundant than carotenoids. Hesperidin was the main flavonoid in most varieties, but cocktail grapefruit and Changshanhuyou contained naringin, with Ponkan having the most abundant polymethoxylated flavones (PMFs). The major components of phenolic acids, carotenoids, and limonoids were ferulic acid, β-cryptoxanthin, and limonin, respectively. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) indicated that these components were mostly correlated with each other, and these citrus varieties could be categorized into four groups by pulp and three groups by peel. The obtained results filled the data gap for secondary metabolites from local citrus and could provide data references for citrus resource utilization, selection and breeding of superior varieties, and other research.

Molecular structures, chemical descriptors, and pancreatic lipase (1LPB) inhibition by natural products: a DFT investigation and molecular docking prediction

Density functional theory (DFT) calculations and molecular docking have been carried out on natural products containing eugenol, gingerol, ascorbic acid, oleurpoein, piperine, hesperidin, quercetin, Luteolin, and curcumin in order to predict their biological activities and to analyze their pancreatic lipase inhibition. The biological activity predictions are based on the global and local chemical descriptors, namely, HOMO-LUMO gaps, chemical hardness, chemical potential, electrophilicity, dipole moment, and Fukui functions. Our findings show that the studied compounds can be divided into two groups based on the chemical descriptors; the first group is composed of eugenol, gingerol, ascorbic acid, and oleuropein and the second one is composed of piperine, hesperidin, quercetin, Luteolin, and curcumin depending on the HOMO-LUMO gaps and electrophilicity values predicting best reactivity for the second group than the first one. The frontier orbitals offer a deeper insight concerning the electron donor and electron acceptor capabilities, whereas the local descriptors resulting from Fukui functions put emphasis on the active sites of different candidate ligands. The molecular docking was performed in order to compare and identify the inhibition activity of the natural candidate ligands against pancreatic lipase which were compared to that of synthesized ones. The molecular docking results revealed that the Luteolin compound has the best binding affinity of -8.56 kcal/mol due to their unique molecular structure and the position of -OH aromatic substituents.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11224-023-02176-2.

Screening and identification of lipase inhibitors extracted from Dioscorea nipponica Makino by UV-vis and HPLC coupled to UPLC-Q-TOF-MS/MS

Dioscoreae nipponica Makino (D. nipponica) as the rhizome of dioscoreaceae rich in steroidal saponins, has been reported to have the hypolipidemic effects etc. However, it is still unclear which exact active components are primary responsible for the beneficial effects. This study was conducted to fish out the lipase inhibitors from D. nipponica, and evaluate the inhibitory activity on porcine pancreatic lipase (PPL) through in vitro kinetic assay using p-nitrophenyl palmitate as substrate. Accordingly, the ethanolic extract was subjected to D101 macroporous resin purification for spectrophotometric screening, high performance liquid chromatography (HPLC) separation and structural characterization by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Through orlistat validation, the PPL inhibitory activity and IC₅₀ value of the extract were respectively 68.34 ± 1.47 % and 107.05 μg/mL under the optimized inhibition conditions. From 6 steroidal saponins identified, the inhibitory components named the protodioscin, protogracillin, dioscin and gracillin were fished out by grouping separation and HPLC analysis. Furthermore, dioscin and gracillin with the parent structure of diogenin were confirmed as the major inhibitors by virtue of stability tests based on transformation of protodioscin and protogracillin. Finally, the inhibitory mechanism of the major inhibitors toward PPL was further clarified by kinetic analysis and molecular docking analysis. The proposed method not only revealed the PPL inhibitory components in D. nipponica, but also provided an effective approach to hierarchical screening of PPL inhibitors from natural plants.

Exploring the binding effects and inhibiting mechanism of hyperoside to lipase using multi-spectroscopic approaches, isothermal titration calorimetry, inhibition kinetics and molecular dynamics

Hyperoside (HYP) is a flavonoid with various physiological activities. The present study examined the interaction mechanism between HYP and lipase using multi-spectrum and computer-aided techniques. Results demonstrated that the force type of HYP on lipase was mainly hydrogen bond, hydrophobic interaction force, and van der Waals force, and HYP had an excellent binding affinity with lipase at 1.576 × 10⁵ M^-1. HYP dose-dependently inhibited lipase in the inhibition experiment, and its IC₅₀ value was 1.92 × 10^-3 M. Moreover, the results suggested that HYP could inhibit the activity by binding to essential groups. Conformational studies indicated that the conformation and microenvironment of lipase were slightly changed after the addition of HYP. Computational simulations further confirmed the structural relationships of HYP to lipase. The interaction between HYP and lipase can provide ideas for the development of functional foods related to weight loss. The results of this study help comprehend the pathological significance of HYP in biological systems, as well as its mechanism.

Digestive and gastroprotective effects of Achillea erba-rotta subsp. moschata (Wulfen) I.Richardson (syn. A. moschata Wulfen) (Asteraceae): From traditional uses to preclinical studies

ETHNOPHARMACOLOGICAL RELEVANCE

Achillea erba-rotta subsp. moschata (Wulfen) I.Richardson (syn. A. moschata Wulfen) (Asteraceae) is an alpine endemic plant whose aerial parts are harvested by the locals mainly for the digestive properties. Despite its widespread use, few studies have been conducted to date to verify its bioactivity.

AIM OF THE STUDY

The purpose of the work was to meet the tradition confirming with experimental data the popular belief that the consumption of this species offers beneficial effects to the gastrointestinal system.

MATERIALS AND METHODS

Using Soxhlet apparatus, the dried aerial parts of A. erba-rotta subsp. moschata were successively extracted with petroleum ether (PET), dichloromethane (DCM) and methanol (MeOH). The essential oil (EO) was obtained by hydrodistillation using a Clevenger apparatus while infusion (AE) was prepared following the traditional local recipe. Their chemical characterization was performed by various techniques including SPME-GC/MS, GC/MS and HPLC/MS-MS. An in vitro biological screening was carried out. The influence of AE on lipid digestion was monitored by titration of free fatty acids (FFA) during pancreatic lipase activity with the pH-stat method. For all extracts and EO, the anti-Helicobacter pylori activity was assessed by the broth microdilution method, the influence on cell viability was evaluated against NCI-N87, OE21 and Caco-2 cell lines and a preliminary toxicity evaluation was done using Brine Shrimp lethality (BSL) assay. The anti-inflammatory potential was evidenced by interleukin IL-1- induced IL8 expression on Caco-2 cells.

RESULTS

AE increased by 15% the FFA releasing compared to the pancreatic lipase alone. PET, DCM and MeOH extracts as well as AE and EO were considered active against the growth of both antimicrobial susceptible and resistant strains of H. pylori with MIC values starting from 16 μg/mL. PET and DCM (IC₅₀ = 89 μg/mL and 96 μg/mL, respectively, against Caco-2 cell line) extracts showed the high effect on cell viability while the EO reduced in 50% of cell viability at 1.48 μL/mL (NCI-N87 cells), 1.42 μL/mL (OE21 cells), and 3.44 μL/mL (Caco-2 cells) corroborating the BSL results. In different degrees, all extracts and EO inhibited the IL-1β-stimulated IL-8 production in Caco-2 cells.

CONCLUSIONS

The obtained data are encouraging and provide a scientific basis for the traditional use of A. erba-rotta subsp. moschata as a digestive agent although they need to be further corroborated by studies involving the investigation of both the in vivo activities and the role of the compounds detected in the extracts.

Evaluation of the impact of hydrogen-rich water on the quality attribute notes of butter

The effects of washing raw butter with hydrogen-rich water (HRW), prepared with hydrogen (H₂) and/or magnesium (Mg), on butter quality were investigated in this research paper. During the washing process, titratable acidity (TA) decreased by 12% for all washed samples. During the storage period, TA increased by 28% and 93% (control), 14% and 58% (H₂), and 10% and 66% (Mg) for the 60^th and 90^th days, respectively. Peroxide value (mEq O₂/kg) increased to 2.76 and 8.83 (control), 1.92 and 7.25 (H₂), and 2.02 and 8.12 (Mg) for the 60^th and 90^th days. HRW samples showed the lowest acid degree value (ADV) and the highest color notes (L*, C*, and h). The HRW treatment of raw butter has shown improving effects on the product without any harmful residuals in the final product or the environment.

The flavonoid profiles in the pulp of different pomelo (Citrus grandis L. Osbeck) and grapefruit (Citrus paradisi Mcfad) cultivars and their in vitro bioactivity

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Fourteen flavonoid compounds were detected in pomelo and grapefruit pulp.

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The flavonoid profiles in pomelo and grapefruit pulp had varietal difference.

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Flavonoids of pomelo and grapefruit showed strong cellular antioxidant activity.

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Flavonoids of pomelo and grapefruit are good inhibitors of pancreatic lipase.

Previous results indicated that the flavonoid profiles might have varietal differences in pomelo, but detailed information is unknown. We previously isolated 4 new flavonoids, cigranoside C, D, E, F, in Citrus grandis Shatianyu pulp. However, their distribution in different pomelo cultivars remains to be explored. Therefore, the flavonoid profiles and in vitro bioactivity of the pulp from 5 pomelo and 1 grapefruit cultivars commonly consumed in China were investigated. Fourteen flavonoids were identified, cigranoside C, D, E were detected in these pomelo and grapefruit. Naringin and cigranoside C were the major flavonoids in grapefruit, Guanximiyu-W, Guanximiyu-R and Liangpingyu, while melitidin and rhoifolin was the predominant flavonoid in Shatianyu and Yuhuanyu, respectively. Pomelo and grapefruit showed strong antioxidant activity, and were potent inhibitors of pancreatic lipase with IC₅₀ values of 11.4–72.6 mg fruit/mL except Shatianyu. Thus, pomelo and grapefruit are natural antioxidants and possess anti-obesity potential.

In vitro determination of anti-lipidemic, anti-inflammatory, and anti-oxidant properties and proximate composition of range of millet types and sorghum varieties in Sri Lanka

Methanolic extracts of whole grains of five millet types and two sorghum varieties were evaluated for anti-lipidemic, anti-inflammatory, and a range of anti-oxidant properties in vitro (n = 3 each). Furthermore, proximate composition (n = 3 each) was also studied. Results showed significant differences (P &lt; 0.05) among the selected samples for studied parameters. Pancreatic lipase and cholesterol esterase inhibitory activities of selected samples (2 mg/ml) ranged from 21.16 ± 1.58 to 66.65 ± 3.30 and 17.43 ± 0.60 to 52.09 ± 1.61%, respectively. Nitric oxide inhibitory activity of selected samples (2 mg/ml) ranged from −1.17 ± 0.32 to 13.56 ± 0.93%. Total polyphenolic content (TPC), total flavonoid content (TFC), and total proanthocyanidin content (TPAC) were in the range of 0.19 ± 0.01–12.50 ± 0.87 mg gallic acid equivalents/g, 0.05 ± 0.00–1.57 ± 0.01 mg quercetin equivalents/g, and 0.35 ± 0.01–12.87 ± 0.25 mg cyaniding equivalents/g of samples, respectively. Ferric reducing anti-oxidant power, oxygen radical absorbance capacity, ferrous ion chelating activity, and ABTS and DPPH anti-oxidant properties ranged from 0.15 ± 0.00 to 4.56 ± 0.03 mg of Trolox equivalents (TEs)/g, 0.19 ± 0.01 to 8.50 ± 0.72 mg of TEs/g, 0.13 ± 0.00 to 0.79 ± 0.03 mg EDTA equivalents/g, 0.22 ± 0.00 to 25.57 ± 0.35 mg of TEs/g, and 0.07 ± 0.00 to 22.97 ± 0.83 mg of TEs/g of samples, respectively. Among the studied samples, pigmented sweet sorghum exhibited the highest activities for all the tested parameters. The observed activities were moderate compared to the reference standards used. The highest values for proximate composition parameters tested varied with the different samples studied. In conclusion, the consumption of especially pigmented millet and sorghum in Sri Lanka may play an important role in the prevention and management of oxidative stress–associated chronic diseases. This is the first study to report pancreatic lipase and cholesterol esterase inhibitory activities of any millet types and sorghum varieties in Sri Lanka and the first report of cholesterol esterase inhibitory activity of millet and sorghum the world over.