Phenolic compositions and antioxidant attributes of leaves and stems from three inbred varieties of Lycium chinense Miller harvested at various times

Research Progress on Bioactive Substances of Beets and Their Functions

As a globally cultivated and economic crop, beets are particularly important in the cane sugar and feed industries. Beet pigments are among the most important natural pigments, while various chemical components in beets display beneficial biological functions. Phenolic substances and betalains, as the main bioactive compounds, determine the functional characteristics of beets. This review categorizes the basic types of beets by the chemical composition of bioactive substances in their leaves, stems, and roots and emphatically summarizes the research progress made on the functions of two major substances in different types of beets: phenolic compounds and betalain pigments. This study provides useful insights for the comprehensive and effective application of beets in the health food and pharmaceutical industries.

Exploring phytochemicals and pharmacological properties of Populus × tomentiglandulosa

Populus × tomentiglandulosa (PT), a tree endemic to Korea, shows promising potential as a natural therapeutic agent owing to its potent anti-inflammatory properties. However, the isolation and analysis of phytochemical compounds in PT and related species remains underexplored. Therefore, this study aims to investigate the biochemical profile of PT and evaluate its extracts and fractions for anti-inflammatory activities. Nine compounds were isolated, including two novel flavonoids (luteolin 7-O-β-d-glucuronide butyl ester and chrysoeriol 7-O-β-d-glucuronide butyl ester) from the Salicaceae family for the first time. The ethyl acetate fraction exhibited significant radical scavenging activity against various radicals, including DPPH, ABTS+, •OH, and O2 - radicals. PT extracts and the ethyl acetate fraction showed minimal cytotoxicity in Raw 264.7 macrophages at concentrations below 500 and 100 μg/mL, respectively. Furthermore, PT extracts and fractions significantly suppressed the protein expression of proinflammatory mediators (iNOS and IL-6) in LPS-stimulated Raw 264.7 macrophages, highlighting their potent anti-inflammatory effects. These findings suggest that PT holds promise as a valuable natural therapeutic intervention for various oxidative stress and inflammation-related disorders, underscoring the need for further exploration of its clinical applications.

Unveiling the Antioxidant, Cytotoxic, and Anti-Inflammatory Activities and Chemical Compositional Information of an Invasive Plant: Lycium ferocissimum Miers

In this study, the antioxidant (DPPH and ABTS radical-scavenging, ferric-reducing, iron (II)-chelating), anti-inflammatory (LPS-induced Raw 264.7 cell line), and cytotoxic activities (Du145 and A549 cell lines) of raw fruit, ripe fruit and leaves of the Lycium ferocissimum species were examined. By using high-pressure liquid chromatography, p-OH benzoic acid, caffeic acid, and rutin were detected in the ethanol and water extracts. For the most active raw fruit ethanol extract, the IC50 in terms of the DPPH-scavenging activity was 0.57 mg/mL, and the ABTS inhibition percentage was 88.73% at a 3 mg/mL concentration. The raw fruit ethanol extract exhibited significant inhibition of viability in the Du145 cell line in the concentration range of 62.5-1000 µg/mL. Additionally, the extract effectively reduced the LPS-induced inflammation parameters (TNF-α, IFN-γ, PGE 2, and NO) at a concentration of 31.25 µg/mL. The biological activities of L. ferocissimum, which have been elucidated for the first time, have yielded promising results.

Establishment of high performance liquid chromatographic fingerprint and determination of 4 kinds of phenolic acid bioactive substances of fruitless Lycium barbarum leaves from Ningxia at different harvesting periods

"Fruitless Lycium barbarum leaf (FLBL) are the leaves of a new variety of Lycium barbarum in Ningxia, which exhibit higher content of various nutrients, trace elements, and bioactive substances compared to Lycium barbarum fruits and leaves. However, the health and medicinal value as well as the by-products derived from FLBL have not received sufficient attention, and the contents of main components vary at different harvesting periods. Therefore, for the first time this study aimed to establish high-performance liquid chromatography (HPLC) fingerprints and determine the contents of four phenolic acid bioactive substances during different harvesting periods in order to provide an experimental basis for cultivation, collection, and research on FLBL. The results revealed 17 common peaks among 10 batches samples with a similarity ranging from 0.71 to 0.976. The linear relationships R2 for catechin, epicatechin-catechin, chlorogenic acid, and rutin were determined as 0.9999 each; meanwhile, the average recovery rate ranged from 93.92 % to 120.11 %, with an RSD between 0.91 % and 2.82 %. The precision, repeatability stability (24 h), and recovery rate met the requirements outlined in "Chinese Pharmacopoeia". Catechin, epicatechin, and rutin exhibited higher levels from June to August, while chlorogenic acid showed increased levels from July to September. The findings serve as a foundation for quality control measures such as identifying optimal harvest periods or facilitating development and production processes related to Ningxia FLBL."

Phenolic mapping and associated antioxidant activities through the annual growth cycle of sugar maple leaves

Concentrations of antioxidant components (analyzed by HPLC-UV) and antioxidant attributes (assayed by radical scavenging and non-radical redox potential methods) of sugar maple leaves (SML) from different harvesting times were investigated. Moreover, measurements of colorimetry, SEM, and FTIR spectroscopy-based characterization of leaves composition, throughout the growth cycle, were performed. Results showed that the antioxidant activities of SML are strongly correlated with phenolic contents and significantly (p < 0.05) varied with harvesting time where minimum amount of total phenolics (105.67 ± 13.16 mg GAE/g DM) and total flavonoids (3.27 ± 0.26 mg CTE/g DM) were found to be concentrated in Fall leaves. The absorption bands obtained from FTIR spectra revealed the presence of functional groups that have great significance towards the antioxidant activity of SML. Principal component analysis revealed that biosynthesis of maximum phenolic compounds in SML mostly occurs during the leaf expansion and growth phases. The obtained data provided a better understanding towards the effect of harvesting time on the phenolic mapping of SML in favor of its valorization into functional food ingredients.

Variation in the Main Health-Promoting Compounds and Antioxidant Capacity of Three Leafy Vegetables in Southwest China

Malabar spinach (Basella alba), amaranth (Amaranthus tricolor), and sweet potato (Ipomoea batatas) are leafy vegetables found in Southwest China. The variation of chlorophyll, carotenoids, ascorbic acid, total flavonoids, phenolic compounds, and antioxidant capacity was studied in the leaves and stems of the three vegetables. The content of main health-promoting compounds and the antioxidant capacity in the leaves were higher than that in the stems, indicating that the leaves of the three vegetables possess greater nutritional value. The trend of total flavonoids in all three vegetables was similar to the trend of antioxidant capacity, suggesting that the total flavonoids may be the major antioxidants wihin these vegetables. Eight individual phenolic compounds were detected in three different vegetables. The most abundant levels of individual phenolic compounds in the leaves and stems of malabar spinach, amaranth, and sweet potato were 6'-O-feruloyl-d-sucrose (9.04 and 2.03 mg g^-1 DW), hydroxyferulic acid (10.14 and 0.73 mg g^-1 DW), and isorhamnetin-7-O-glucoside (34.93 and 6.76 mg g^-1 DW), respectively. Sweet potato exhibited a higher total and individual phenolic compound content compared to malabar spinach and amaranth. Overall, the results demonstrate that the three leafy vegetables possess high nutritional value, and could be used not only for consumption but also in various other fields, including medicine and chemistry.

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.

Evaluation of Bioactive Properties of Lipophilic Fractions of Edible and Non-Edible Parts of Nasturtium officinale (Watercress) in a Model of Human Malignant Melanoma Cells

Watercress is an enriched source of phenethyl isothiocyanate (PEITC), among other phytochemicals, with an antioxidant capacity. The aim of this study was to (i) chemically characterize and (ii) biologically evaluate the profile of the main health-promoting compounds contained in edible (i.e., mixture of leaves and lateral buds) and non-edible (i.e., stems) parts of watercress in an in vitro model of malignant melanoma consisting of human malignant melanoma (A375), non-melanoma (A431) and keratinocyte (HaCaT) cells. The extraction of the main constituents of watercress was performed by subjecting the freeze-dried edible and non-edible samples through different extraction protocols, whereas their concentration was obtained utilizing analytical methodologies. In addition, cell viability was evaluated by the Alamar Blue assay, whereas levels of oxidative stress and apoptosis were determined by commercially available kits. The edible watercress sample contained a higher amount of various nutrients and phytochemicals in the hexane fraction compared to the non-edible one, as evidenced by the presence of PEITC, phenolics, flavonoids, pigments, ascorbic acid, etc. The cytotoxicity potential of the edible watercress sample in the hexane fraction was considerably higher than the non-edible one in A375 cells, whereas A431 and HaCaT cells appeared to be either more resistant or minimally affected, respectively. Finally, levels of oxidative stress and apoptotic induction were increased in both watercress samples, but the magnitude of the induction was much higher in the edible than the non-edible watercress samples. Herein, we provide further evidence documenting the potential development of watercress extracts (including watercress waste by-products) as promising anti-cancer agent(s) against malignant melanoma cells.

Simultaneous determination of four phenolic acids in traditional Chinese medicine by capillary electrophoresis-chemiluminescence

Chlorogenic, ferulic, vanillic, and caffeic acids are phenolic acids found in natural drugs. They possess the biological activities of scavenging free radicals and inhibiting thrombus formation. Phenolic acids can inhibit the oxidation of low-density lipoprotein, as well as have anti-inflammatory effects. This paper reports for the first time a capillary electrophoresis-chemiluminescence (CE-CL) method for the simultaneous determination of the four phenolic acids found in traditional and proprietary Chinese medicine, including Lycium chinense Miller, Shuanghuanglian oral liquid, and Taraxacum mongolicum granules. Capillary electrophoretic separation was performed on a self-assembled CE-CL device with an uncoated fused-silica capillary (66 cm effective length, 50 μm i.d.), and the background electrolyte was composed of 3.0 × 10-5 M Ag(iii) (pH = 12.01), 3.0 mM luminol (pH = 9.20), and 10 mM sodium tetraborate solution. The injection time was 12 s (under gravity) and the separation voltage was 22 kV. The combination of solid-phase extraction (SPE) and CE-CL improves the sensitivity. Under optimal conditions, calibration graphs displayed a linear range between 0.625 and 20.0, 1.000 and 30.0, 0.150 and 1.50, and 0.045 and 1.00 μg mL-1 for chlorogenic, ferulic, vanillic, and caffeic acid, respectively. The detection limit ranged from 0.014 to 0.300 μg mL-1. The practicality of using the proposed method to determine the four target analytes in traditional Chinese medicine was also validated, in which recoveries ranged from 90.9% to 119.8%. Taken together, these results indicate that the developed method is sensitive and reliable. Furthermore, the method was successfully applied to real traditional Chinese medicine samples.

Effect of flavonoids from Lycium barbarum leaves on the oxidation of myofibrillar proteins in minced mutton during chilled storage

Herein, we report the effect of flavonoids from Lycium barbarum leaves (LBLF) on myofibrillar proteins (MP) in minced mutton during chilled storage (4 ± 1 ℃). High performance liquid chromatography (HPLC) analysis showed that the total flavonoid content in LBLF was 322.0 mg/g, of which the rutin content was 297.6 mg/g. The effect of 0.5%, 1.0%, and 1.5% LBLF on the structure and thermodynamic properties of MP in minced mutton was studied systematically. Tyrosine and tryptophan of MP samples treated with LBLF were converted from an exposed state to an embedded state. The interaction between LBLF and MP quenched the internal fluorescence, and improved the thermal stability of MP. The addition of LBLF significantly reduced the carbonyl and sulfhydryl contents of MP (p < 0.05), and decreased the surface hydrophobicity of MP in a dose-dependent manner. Our results indicate that LBLF can combine with free radicals produced by protein oxidation, block the free radical oxidation chain reaction, and inhibit the oxidation of MP. Therefore, LBLF may have great potential as a natural antioxidant in meats and meat products during chilled storage. PRACTICAL APPLICATION: Lycium barbarum is widely distributed in China, especially in Qinghai and Ningxia. The results of this study suggest that flavonoids extracted from L. barbarum leaves may be an effective natural antioxidant for the preservation of meats and meat products.

Health-Promoting Compounds in Stevia: The Effect of Mycorrhizal Symbiosis, Phosphorus Supply and Harvest Time

This work aimed to establish the synergic role of arbuscular mycorrhizal fungi (AMF) symbiosis, phosphorus (P) fertilization and harvest time on the contents of stevia secondary metabolites. Consequently, steviol glycosides (SVglys) concentration and profile, total phenols and flavonoids as well as antioxidant assays, have been assessed in inoculated and no-inoculated plants, grown with or without P supply and collected at different growth stages(69, 89 and 123 days after transplanting).The obtained results suggest that the synthesis of stevia secondary metabolites is induced and/or modulated by all the investigated variability factors. In particular, AMF symbiosis promoted total SVglys content and positively influenced the concentration of some minor compounds (steviolbioside, dulcoside A and rebaudioside B), indicating a clear effect of mycorrhizal inoculation on SVglys biosynthetic pathway. Interestingly, only the mycorrhizal plants were able to synthesize rebaudioside B. In addition, P supply provided the highest levels of total phenols and flavonoids at leaf level, together with the maximum in vitro antioxidant activities (FRAP and ORAC). Finally, the harvest time carried out during the full vegetative phase enhanced the entire composition of the phytocomplex (steviolbioside, dulcoside A, stevioside, rebaudioside A, B, C. total phenols and flavonoids). Moreover, polyphenols and SVglys appeared to be the main contributors to the in vitro antioxidant capacity, while only total phenols mostly contributed to the cellular antioxidant activity (CAA). These findings provide original information about the role played by AMF in association with P supply, in modulating the accumulation of bioactive compounds during stevia growth. At the cultivation level, the control of these preharvest factors, together with the most appropriate harvest time, can be used as tools for improving the nutraceutical value of raw material, with particular attention to its exploitation as functional ingredient for food and dietary supplements and cosmetics.

Assessment of Mineral and Phenolic Profiles and Their Association with the Antioxidant, Cytotoxic Effect, and Antimicrobial Potential of Lycium chinense Miller

This study aimed at investigating the Lycium chinense Miller leaf extract mineral and phenolic compound profiles as well as antioxidant and antimicrobial potential. We determined the leaf extract mineral composition, identified its major mineral components, and quantified secondary metabolites. We also measured the leaf extract antioxidant potential and found that it varies in a concentration-dependent manner. We observed a significant and higher positive correlation between DPPH and ABTS assays compared with the total phenolic and flavonoid content. Furthermore, our assay results positively correlated with several observed acids, indicating their strong association with the L. chinense antioxidant potential. Our cytotoxic assay revealed weak toxicity at higher tested concentrations. Our MIC assay showed that the 80% methanol extract effectively inhibited the growth of Escherichia coli Castellani and Chalmers (ATCC35150). The 625-ppm leaf extract completely suppressed the growth of Staphylococcus aureus Rosenbach (ATCC13150), Bacillus cereus (ATCC 14579), and Helicobacter pylori (ATCC43504). These results allow us to understand the indigenous medicinal value of L. chinense. Our study suggests that the L. chinense leaf extract phenolic compounds possess a good antioxidant activity against free radicals and are effective antimicrobial agents. Finally, the presence and high level of diverse minerals suggest the potential of L. chinense for nutraceutical and functional food applications.

Biologically Active Compounds from Goji (Lycium Barbarum L.) Leaves Aqueous Extracts: Purification and Concentration by Membrane Processes

Goji (Lycium barbarum L.) leaves and fruits have been described as a valuable source of bioactive compounds with a great potential for the development of health-promoting formulations. The present study aimed to evaluate the potential of a sustainable process for the recovery of phenolic compounds from Goji leaves through a combination of aqueous extraction and membrane-based operations. Water was used as a safe, cheap, and non-hazardous extraction solvent, and parameters of extraction of dried Goji leaves were optimized in order to maximize the yield of polyphenols, total soluble solids (TSS), and total antioxidants simultaneously. The aqueous extract was clarified by ultrafiltration and then processed with three flat-sheet polyethersulphone (PES) membranes with molecular weight cut-off (MWCO) values in the range of 0.3–4.0 kDa, in order to remove sugar compounds from polyphenols and improve the antioxidant activity of the produced fractions. Among the selected membranes, a 1 kDa membrane exhibited the best performance in terms of purification of polyphenols from the clarified aqueous extract. The rejection by this membrane of TSS and total carbohydrates was in the range of 15.8–25.3%, and was decreased by increasing the volume reduction factor (VRF). On the other hand, the retention values for total polyphenols and total antioxidant activity (TAA) were in the range of 73–80%, and were increased by increasing the VRF.

Phytochemical composition profile and space-time accumulation of secondary metabolites for Dracocephalum moldavica Linn. via UPLC-Q/TOF-MS and HPLC-DAD method

The aerial parts of Dracocephalum moldavica L. are extensively used in traditional ethnic medicines in China as a remedy for cardiovascular and cerebrovascular damage. However, the chemical composition and the accumulation of main secondary metabolites of D. moldavica in different natural environments remain unclear. This study aimed to conduct a qualitative and quantitative analysis of the main secondary metabolites to explore the quality variation of D. moldavica in markets. The evaluation of space-time accumulation of main secondary metabolites in D. moldavica was carried out during different growth periods and in different geographical locations. A total of 35 ingredients were detected and 24 identified, including 21 flavonoids, two phenolic acids and one coumarin by UPLC-QTOF-MS method. Furthermore, a simple and convenient HPLC method was successfully developed for the simultaneous determination of lutelin-7-O-glucuronide and tilianin and rosmarinic acid in D. moldavica. The results of space-time accumulation analysis showed the distinct variation of secondary metabolites of D. moldavica with the growth period and geographical location. Finally, the current study provided a meaningful and useful approach for comprehensively evaluating the quality of D. moldavica.

Phytochemical study and antioxidant activity of Dalbergia ecastaphyllum

Abstract The chemical profile of Dalbergia ecastaphyllum has been indicated as the botanical origin of Brazilian red propolis, an apicultural product with proven therapeutic properties. However, few studies have investigated this plant species. This study evaluated and compared microbiological quality, chemical composition, and antioxidant activity of stem and leaf samples of D. ecastaphyllum. The samples were collected in February 2015, in the southern region of the state of Bahia, Brazil. We performed the microbiological analyses, determined the contents of fatty acid, total phenol and flavonoid, and identified the chemical profile and antioxidant activit. Escherichia coli, Salmonella spp. and sulfite reducing clostridial spores were not detected in the samples. Acids of the family ω3 were recorded in the stems and ω6 in the leaves. The leaves presented better nutritional quality of the fraction, better antioxidant capacity in the tests by the DPPH method and β-carotene bleaching. There were 49 chemical compounds, of which 38 belonged to the class of flavonoids. The results indicate that stems and leaves of D. ecastaphyllum have biological properties. Leaves particularly are better for functional food formulation and as natural antioxidant.

Quality Evaluation of Thirteen Geographical Populations of Lycium chinense Using Quantitative Analysis of Nutrients and Bioactive Components

Lycium chinense Mill. is an important medicinal and edible perennial plant that has been developed as a popular vegetable and healthcare tea in southern China in recent years. In this study, we evaluated the nutritional quality of 13 different geographical L. chinense populations through a common-garden experiment. There were significant differences (P<0.05) in active components and nutrient elements among the populations. Principal component and clustering analyses showed that populations in the central China showed better integrated quality than the other populations; populations in southern China also showed good prospects for further development, having special characteristics such as high contents of amino acids, total flavonoids, and chlorogenic acid. Moreover, all the populations had much higher contents than most vegetables of flavonoids and of the mineral elements Fe, Se, Mn, and K. These results provide important information required for the development of L. chinense germplasm resources and to ensure the sustainable utilization of L. chinense.

HPLC-DAD-ESI-MS/MS screening of phytochemical compounds and the bioactive properties of different plant parts of Zizyphus lotus (L.) Desf

Zizyphus lotus L. (Desf.) has been widely used as a homemade ingredient to treat numerous diseases in Algerian folk medicine. In this context, decoction, infusion and hydroethanolic extracts were prepared from the branches, leaves, roots, and stem barks. The extracts were characterized regarding their phytochemical composition by HPLC-DAD-ESI/MSⁿ and were assessed for in vitro bioactivity (cytotoxicity, anti-inflammatory activity, and antibacterial activity). A total of 29 compounds (flavonoid derivatives and secoiridoids) were identified in Z. lotus, 15 being detected in leaves, 10 in branches, 5 in roots and 7 in stem barks. The highest contents of these compounds, especially secoiridoids, were detected in branches followed by leaves, oleuropein being the main compound detected in leaves and oleoside in branches. The aqueous preparations of the leaves and root barks revealed the highest cytotoxicity and anti-inflammatory potential. On the other hand, as for the antibacterial activity, the hydroethanolic extract of the branches showed the highest potential, especially against the MSSA strain. Hence, the chemical diversity found in Z. lotus makes it a source of bioactive ingredients that can be applied in the formulations of different ingredients in the food and pharmaceutical industries.

Phenol Profiling and Nutraceutical Potential of Lycium spp. Leaf Extracts Obtained with Ultrasound and Microwave Assisted Techniques

In recent years, agricultural and industrial residues have attracted a lot of interest in the recovery of phytochemicals used in the food, pharmaceutical, and cosmetic industries. In this paper, a study on the recovery of phenol compounds from Lycium spp. leaves is presented. Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) have been used with alcoholic and hydroalcoholic solvents. Methanolic UAE was the most successful technique for extracting phenols from Lycium leaves, and we used on leaves from L. barbarum and L. chinense cultivated in Italy. The extracts were then characterized as regards to the antioxidant properties by in vitro assays and the phenol profiling by a high performance liquid chromatography-diode array detector (HPLC-DAD). Chlorogenic acid and rutin were the main phenol compounds, but considerable differences have been observed between the samples of the two Lycium species. For example, cryptochlorogenic acid was found only in L. barbarum samples, while quercetin-3-O-rutinoside-7-O-glucoside and quercetin-3-O-sophoroside-7-O-rhamnoside only in L. chinense leaves. Finally, multivariate statistical analysis techniques applied to the phenol content allowed us to differentiate samples from different Lycium spp. The results of this study confirm that the extraction is a crucial step in the analytical procedure and show that Lycium leaves represent an interesting source of antioxidant compounds, with potential use in the nutraceutical field.

Changes in the profiling of bioactive components with the roasting process in Lycium chinense leaves and the anti-obesity effect of its bioaccessible fractions

BACKGROUND

This study aimed to investigate the profiles of bioactive components in roasted Lycium chinense leaves (LCLs) and its in vitro anti-obesity activity after digestion processes.

RESULTS

Chlorogenic acid, kaempferol-3-sophoroside-7-glucoside, kaempferol-3-sophoroside, and kaempferol-3-glucoside were discovered as bioactive components in various ratios of ethanol (EtOH) extract in LCLs by using ultra-performance liquid chromatography-electrospray ionization-mass spectrophotometry (UPLC-ESI-MS). The roasting process followed by a 30% EtOH extraction tended to decrease the content of chlorogenic acid and kaempferol-3-glucoside, and enhanced the content of kaempferol-3-sophoroside-7-glucoside. It effectively inhibited pancreatic lipase activity by 62.50 ± 4.81%, which was approximately 1.71 percentage points higher than that of the dried-nonroasted LCL extract (60.79 ± 3.75%). Its bioaccessible fraction obtained from in vitro digestion significantly and dose dependently reduced intracellular lipid accumulation by adipocyte 3T3-L1 compared with a 30% EtOH extraction. At a concentration of 200 μg mL^-1 , it inhibited lipid accumulation up to 29.55% in 3T3-L1 cells, which indicated that human digestive enzymes converted kaempferol-3-sophoroside-7-glucoside to kaempferol metabolites that have anti-obesity effects.

CONCLUSION

This study suggests that the profiling of bioactive components by processing methods and a bioaccessible fraction could be crucial to improve the bioactivity of LCLs, and potentially be a natural anti-obesity ingredient after oral intake. © 2019 Society of Chemical Industry.

Phenolic compositions and antioxidant properties of leaves of eight persimmon varieties harvested in different periods

The compositions and contents of antioxidant components and antioxidant attributes (scavenging DPPH radicals, TEAC, ferric reducing power and inhibiting Cu²⁺-induced human LDL oxidation) for the leaves of eight persimmon varieties harvested from Sep. to Nov. were determined. Harvest time and variety were important factors affecting the compositions and contents of phenolic compounds in persimmon leaves; moreover, phenolic contents (polyphenol, flavonoid, condensed tannin and phenolic acid) of the leaves were significantly correlated with their antioxidant activities. For each variety, the leaves harvested in months with higher temperature, solar radiation and sunshine duration had higher phenolic contents contributing to better antioxidant properties (ranking: Sep. > Oct. > Nov.). In addition, the compositions and contents of phenolic components and antioxidant capacities for the leaves from various persimmon varieties were also different. The leaves of persimmon varieties belonging to pollination constant and astringent (PCA) had higher phenolic contents and also presented better antioxidant effects.

The Potential Protective Effects of Phenolic Compounds against Low-density Lipoprotein Oxidation

BACKGROUND

The exact mechanism(s) of atherosclerosis in humans remains elusive, but one theory hypothesizes that this deleterious process results from the oxidative modification of low-density lipoprotein (LDL). Research suggests that foods rich in dietary phenolic compounds with antioxidant activity can mitigate the extent of LDL oxidation in vivo. With regard to the different classes of flavonoids, there appears to be a structurefunction relationship between the various moieties/constituents attached to the flavonoids' three ring system and their impact at retarding LDL oxidation.

METHODS

This article summarizes the findings to date of both in vitro and in vivo studies using foods or phenolic extracts isolated from foodstuffs at inhibiting the incidence of LDL oxidation. Three bases: SCOPUS, Web Science, and PubMed were used for search.

RESULTS

An often used method for the determination of antioxidant properties of natural phenolic compounds is the LDL oxidation assay. LDLs are isolated from human plasma and their oxidation is induced by Cu2+ ions or 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH). The sample is incubated with a phenolic extract or individual/isolated phenolic compounds. LDL oxidation is then monitored by various chemical methods (e.g., measurement of the generation of conjugated dienes and trienes). This technique confirmed the antioxidant properties of several extracts as obtained from plant material (e.g., grapes, berries, orange, grapefruit, coffee, tea, chocolate, olives, nuts) as well as the individual phenolic compounds (e.g., luteolinidin, apigenidin, caffeic acid, chlorogenic acid, catechin, quercetin, rutin). Several studies in vivo confirmed protective effects of phenolic compounds against LDL oxidation. They covered the healthy subjects with hyperlipidaemia, overweight, obesity, metabolic syndrome, heavy smokers, patients receiving haemodialysis, patients with peripheral vascular disease, and subjects at high cardiovascular risk. The studies comprise individuals of all ages, and the number of participants in the different experiments varied widely.

CONCLUSION

Properly designed double-blind, placebo-controlled randomised clinical trials offer stronger evidence as to the impact of dietary phenolics consumption at retarding LDL oxidation. More such clinical trials are needed to strengthen the hypothesis that foods rich in dietary phenolic compounds with antioxidant activity can mitigate the extent of LDL oxidation in vivo.

Variation in the main health-promoting compounds and antioxidant activity of whole and individual edible parts of baby mustard (Brassica juncea var. gemmifera)

The main differences of health-promoting compounds and antioxidant activity of whole and individual edible parts of baby mustard were demonstrated.

Ameliorative effect of black ginseng extract against oxidative stress-induced cellular damages in mouse hepatocytes

Background

Oxidative stress induces the production of reactive oxygen species (ROS), which play important causative roles in various pathological conditions. Black ginseng (BG), a type of steam-processed ginseng, has drawn significant attention due to its biological activity, and is more potent than white ginseng (WG) or red ginseng (RG).

Methods

We evaluated the protective effects of BG extract (BGE) against oxidative stress-induced cellular damage, in comparison with WG extract (WGE) and RG extract (RGE) in a cell culture model. Ethanolic extracts of WG, RG, and BG were used to evaluate ginsenoside profiles, total polyphenols, flavonoid contents, and antioxidant activity. Using AML-12 cells treated with H₂O₂, the protective effects of WGE, RGE, and BGE on cellular redox status, DNA, protein, lipid damage, and apoptosis levels were investigated.

Results

BGE exhibited significantly enhanced antioxidant potential, as well as total flavonoid and polyphenol contents. ATP levels were significantly higher in BGE-treated cells than in control; ROS generation and glutathione disulfide levels were lower but glutathione (GSH) and NADPH levels were higher in BGE-treated cells than in other groups. Pretreatment with BGE inhibited apoptosis and therefore protected cells from oxidative stress-induced cellular damage, probably through ROS scavenging.

Conclusion

Collectively, our results demonstrate that BGE protects AML-12 cells from oxidative stress-induced cellular damages more effectively than WGE or RGE, through ROS scavenging, maintenance of redox status, and activation of the antioxidant defense system.

Phytochemical characterization and bioactivity of Lycium europaeum: A focus on antioxidant, antinociceptive, hepatoprotective and nephroprotective effects

In this study, the antioxidant, antinociceptive, hepatoprotective, nephroprotective properties and the bioactive composition of Lycium europaeum were investigated. Polyphenols and total tannin contents were measured by colorimetric methods The antioxidant activity in vitro was evaluated using the reducing power, 2,2-diphenyl-1-picrylhydrazyl radical and phosphomolybdenum assays. The hepatotoxicity and nephrotoxicity effects were studied using carbon tetrachloride (CCl₄)-induced liver and renal injuries in mice. The analgesic activity was explored using the hot-plate and acetic acid tests in mice. Results showed that the methanol fraction of L. europaeum (LEM) had the highest level of total phenolic, total tannin, and flavonoid. HPLC-DAD analysis revealed the presence of twelve compounds among them caffeic acid was the major compound (140.18μg/g of extract). This fraction also showed the best antioxidant activity in vitro in the three used assays. In vivo, in the mice studies, CCl₄ administration induced hepatotoxicity and nephrotoxicity by a significant rise in the levels of serum liver biomarkers (gamma glutamyl transferase, lactate dehydrogenase, and aminotransferases) and serum renal biomarkers (urea, creatinine, and uric acid). Similarly, levels of lipid peroxidation (MDA) in both tissues were found increased by CCl₄ intoxication. Pretreatment with LEM and quercetin significantly restored the majority of these biological parameters to normal levels, as well as an improvement of histopathological changes. In addition, LEM showed an interesting analgesic activity. LEM decreased significantly the number of writhing induced by acetic acid and prolonged the reaction time in response to thermal stimulus in mice. Therefore, it was speculated that the obtained results highlighted the potential use of L. europaeum as a source of bioactive compounds with pharmacological advantages.