Various Antioxidant Effects Were Attributed to Different Components in the Dried Blossoms of Citrus aurantium L. var. amara Engl

Widely Targeted Metabolomics Analysis Reveals Metabolites Important for Antioxidant Properties and Quality Traits in Different Fruit Parts of Aurantii Fructus Immatures

In traditional Chinese medicine, Aurantii Fructus Immatures (AFIs) have been utilized for more than 2000 years. The proportions of different fruit parts are crucial for evaluating AFI quality in China. However, the basis for this statement's substance is unclear. Differences in quality are intimately correlated with a plant's metabolite composition. On the basis of a widely targeted metabolome, this study intended to investigate the metabolite composition and evaluate the antioxidant capacity of the peel and pulp of an AFI. Metabolites were identified and quantified by UHPLC-QqQ-MS. To assess their antioxidant ability, DPPH and ABTS assays were carried out. There were 1327 chemical compounds identified by UHPLC-QqQ-MS. After screening the differential metabolites using a multivariate statistical analysis, it was found that there were 695 significant differences in the metabolites between the peel and the pulp. Among them, it was discovered that the content of active ingredients in the peel group was higher than that in the pulp group. Furthermore, the aqueous extracts from the peel showed stronger antioxidant capacities than those from the pulp. The metabolites and antioxidant capacities were significantly different between the peel and the pulp. This study of different fruit parts might provide a guide for AFI quality assessments.

Scavenging Glyoxal and Methylglyoxal by Synephrine Alone or in Combination with Neohesperidin at High Temperatures

α-Dicarbonyl compounds, such as glyoxal (GO) and methylglyoxal (MGO), are a series of chemical hazards that exist in vivo and in vitro, posing a threat to human health. We aimed to explore the scavenging effects on GO/MGO by synephrine (SYN) alone or in combination with neohesperidin (NEO). First, through LC-MS/MS, we confirmed that both SYN and NEO could effectively remove GO and form GO adducts, while NEO could also clear MGO by forming MGO adducts, and its ability to clear MGO was stronger than that of GO. Second, a synergistic inhibitory effect on GO was found when SYN and NEO were used in combination by using the Chou-Talalay method; on the other hand, SYN could promote NEO to clear more MGO, although SYN could not capture MGO. Third, after synthesizing four GO/MGO-adducts (SYN-GO-1, SYN-GO-3, NEO-GO-7, and NEO-MGO-2) and identifying their structure through NMR, strict correlations between the GO/MGO-adducts and the GO/MGO-clearance rate were found when using SYN and NEO alone or in combination. Furthermore, it was inferred that the synergistic effect between SYN and NEO stems from their mutual promotion in capturing more GO by the quantitative analysis of the adducts in the combined model. Finally, a study was conducted on flowers of Citrus aurantium L. var. amara Engl. (FCAVA, an edible tea) rich in SYN and NEO, which could serve as an effective GO and MGO scavenger in the presence of both GO and MGO. Therefore, our study provided well-defined evidence that SYN and NEO, alone or in combination, could efficiently scavenge GO/MGO at high temperatures, whether in the pure form or located in FCAVA.

Metabolic profiling of the flower of Citrus aurantium L. var. amara Engl. in rats using ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry with data mining strategy

RATIONALE

The flower of Citrus aurantium L. var. amara Engl. (FCAVA), an edible tea and herbal medicine with anti-obesity effect, has attracted great attention in China. The structural elucidation of chemical components in FCAVA has been realized in our previous work. It is well known that metabolic profiling provided a structural basis to discover potential anti-obesity ingredients in FCAVA. Nevertheless, there are no reports about in vivo metabolic profiles of FCAVA. Therefore, it is necessary to comprehensively identify in vivo substances of FCAVA.

METHODS

The identification of in vivo substances of FCAVA remains a challenge due to the strong interference of complex chemical components, biological matrices and metabolite isomers. In this work, ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS) analysis with a data mining strategy was established and applied for the metabolic profiling of FCAVA in rats. The data mining strategy, including diagnostic product ions and neutral loss filtering, improved structural elucidation of xenobiotics in rats after oral administration of FCAVA.

RESULTS

A total of 228 xenobiotics, including 80 prototypes (10 unambiguous confirmed with reference standards) and 148 metabolites, were tentatively characterized in rat plasma, urine and fecal samples. Among them, 35 xenobiotics were found in plasma, 124 in urine and 156 in feces. The main biotransformation pathway of FCAVA metabolism was deglycosylation, methylation, glucuronidation and sulfation. The main compounds absorbed into the blood were neohesperidin and naringin, which have been reported to show significant anti-obesity effect.

CONCLUSIONS

Collectively, this present study would be conducive to the discovery of active ingredients of FCAVA for the treatment of obesity and the development of quality control of FCAVA.

Quality analysis and metabolomic profiling of the effects of exogenous abscisic acid on rabbiteye blueberry

Blueberry is a characteristic berry fruit shrub of the genus Vaccinium in the Rhododendron family. The fruit is rich in anthocyanins and has a variety of nutritional and health functions. This study aimed to systematically study the effect of exogenous abscisic acid (ABA) application on ripening and metabolites in blueberry fruits. Blueberry fruit ripening was divided into six stages for further analysis. In this study, nontarget metabolomics was performed to demonstrate the effect on metabolite levels. The results showed that 1000 mg/L ABA significantly promoted fruit ripening and increased anthocyanin content. Moreover, exogenous ABA treatment can affect endogenous ABA levels and improve its antioxidant capacity. Important metabolites of the flavonoid pathway were detected, and the results showed that anthocyanin synthesis increased, and some other bioactive metabolite levels decreased. After comprehensive assessments, we believe that 1000 mg/L exogenous ABA application will have positive impacts on blueberry fruit quality and economic benefits.

p-Synephrine ameliorates alloxan-induced diabetes mellitus through inhibiting oxidative stress and inflammation via suppressing the NF-kappa B and MAPK pathways

Oxidative stress and inflammation play important roles in the development of diabetes mellitus. p-Synephrine, the primary pharmacologically active protoalkaloid in Citrus species, has been popularly consumed as a dietary supplement for weight loss management. However, the effects of p-synephrine on diabetes mellitus and the action mechanisms have not been clearly elucidated. In this study, the in vitro antioxidant effects of p-synephrine were evaluated. The data showed that p-synephrine treatment exhibited significant scavenging effects against DPPH, ABTS and OH radicals and showed high reducing power. Diabetic mice were developed by alloxan injection, followed by p-synephrine administration to investigate its hypoglycemic effects in vivo. The results showed that p-synephrine intervention significantly prevented alloxan-induced alteration in body weight, organ indexes, serum uric acid content and serum creatinine content. Meanwhile, p-synephrine application significantly improved the lipid profiles, superoxide dismutase (SOD) and catalase (CAT) activities and glutathione (GSH) contents in the serum and kidneys of diabetic mice and reduced the malondialdehyde (MDA) content in the serum of diabetic mice. Further assays suggested that p-synephrine treatment improved alloxan-induced decreases of glucose tolerance and insulin sensitivity. Also, p-synephrine supplementation altered histopathological changes in the kidneys and interscapular brown adipose tissues in diabetic mice. In addition, p-synephrine administration inhibited renal inflammation through suppressing tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) gene expression levels, as well as CD45 expression levels. The anti-inflammatory effects were probably involved in the regulation of nuclear factor-κB (NF-κB) activation and mitogen-activated protein kinase (MAPK) phosphorylation. In conclusion, p-synephrine application significantly ameliorated alloxan-induced diabetes mellitus by inhibiting oxidative stress via suppressing the NF-κB and MAPK pathways.

Effect of fermentation modification on the physicochemical characteristics and anti-aging related activities of Polygonatum kingianum polysaccharides

In order to fully investigate the anti-aging value of the plants polysaccharides, the fermentation method was applied to modify the Polygonatum kingianum polysaccharides (PKPS), and the ultra-filtration was used to further segment the hydrolyzed polysaccharides. It was found that the fermentation induced an increase in the in vitro anti-aging-related activities of PKPS including antioxidant, hypoglycemic and hypolipidemic activity, and cellular aging-delaying ability. In particular, the low Mw fraction PS2-4 (10-50 kDa) separated from the fermented polysaccharide exhibited superior anti-aging activity on experimental animals. PS2-4 extended the Caenorhabditis elegans lifespan by 20.70 %, with an increased effect of 10.09 % compared to the original polysaccharide; it was also more effective than the original one in improving movement ability and reducing lipofuscin accumulation of worms. This fraction was screened as the optimal anti-aging active polysaccharide. After fermentation, the main molecular weight distribution of PKPS changed from 50-650 kDa to 2-100 kDa, and the chemical composition and monosaccharide composition also changed; the initial rough and porous microtopography turned into smooth state. These alterations in physicochemical characteristics suggest that fermentation exerted an influence on the structure of PKPS, which contributed to the enhanced anti-aging activity, indicating that fermentation was promising in the structural modification of polysaccharides.

Glycoside constituents with various antioxidant effects from fresh Cynomorium songaricum

Cynomorium songaricum Rupr. (CSR), an edible and medicinal material, is widely cultivated in desert regions of Eastern and Western Asia, Europe, and North Africa. Ten glycoside constituents 1-10 including one new songaricumone A (1) were isolated from the fresh C. songaricum. Their structures were elucidated by comprehensive NMR data analysis. Further, various antioxidant effects of isolated compounds (1-3 and 5-10) were comprehensively and comparatively investigated. In conclusion, it is obvious that different glycosides vary significantly toward different sources of free radicals, which are attributed to different aglycones and substituted positions of sugar unit in structures.

Ingredients with anti-inflammatory effect from medicine food homology plants

Inflammation occurs when the immune system responses to external harmful stimuli and infection. Chronic inflammation induces various diseases. A variety of foods are prescribed in the traditional medicines of many countries all over the world, which gave birth to the concept of medicine food homology. Over the past few decades, a number of secondary metabolites from medicine food homology plants have been demonstrated to have anti-inflammatory effects. In the present review, the effects and mechanisms of the medicine food homology plants-derived active components on relieving inflammation and inflammation-mediated diseases were summarized and discussed. The information provided in this review is valuable to future studies on anti-inflammatory ingredients derived from medicine food homology plants as drugs or food supplements.

Primary Bitter Taste of Citrus is Linked to a Functional Allele of the 1,2-Rhamnosyltransferase Gene Originating from Citrus grandis

1,2-Rhamnosyltransferase (1,2RhaT) catalyzes the final step of production of flavanone neohesperidoside (FNH) that is responsible for the primary bitter taste of citrus fruits. In this study, species-specific flavonoid profiles were determined in 87 Citrus accessions by identifying eight main flavanone glycosides (FGs). Accumulation of FNHs was completely correlated to the presence of the 1,2RhaT gene in 87 citrus accessions analyzed using a novel 1,2RhaT-specific DNA marker. Pummelo (Citrus grandis) was identified as the genetic origin for a function allele of 1,2RhaT that underpinned FNH-bitterness in modern citrus cultivars. In addition, genes encoding six MYB and five bHLH transcription factors were shown to coexpress with 1,2RhaT and other flavonoid pathway genes related to FNH accumulation, indicating that these transcription factors may affect the fruit taste of citrus. This study provides a better understanding of bitterness formation in Citrus varieties and a genetic marker for the early selection of nonbitterness lines in citrus breeding programs.

Potential roles of dietary flavonoids from Citrus aurantium L. var. amara Engl. in atherosclerosis development

Dietary consumption of flavonoids correlated positively with lower risk of cardiovascular disease. However, the precise roles of flavonoids from the blossoms of Citrus aurantium Linn variant amara Engl (CAVA) in atherosclerosis (AS) are still poorly understood. This study aimed to find novel flavonoid-type skeletons with protection against AS. Total flavonoids (CAVAF), homoeriodictyol (HE) and hesperetin-7-O-β-d-glucopyranoside (HG) were isolated from the blossoms of Citrus aurantium Linn variant amara Engl. by chromatography. Their suppressive effects on lipopolysaccharide (LPS)-induced inflammatory responses and ox-LDL-induced foam cell formation were systematically and comparatively investigated using macrophage RAW264.7 cells. HE was more powerful than HG in inhibiting LPS-induced production of nitric oxide (NO), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β) and gene expression in RAW264.7 cells. HE and HG showed different responses to extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinases (JNK), P38, P65, IκBα, IκKα/β phosphorylation, and nuclear factor-kappa B (NF-κB) nuclear translocation. HE and HG also differentially decreased oxidized low-density lipoprotein (ox-LDL)-induced foam cell formation by regulating peroxisome proliferator-activated receptor-gamma (PPARγ), phospholipid ATP-binding cassette transporter A1 (ABCA1), phospholipid ATP-binding cassette transporter G1 (ABCG1), scavenger receptor class B type I (SRB1), scavenger receptor class A type I (SRA1) and cluster of differentiation 36 (CD36) expression at gene and protein levels in RAW264.7 cells. HG showed weaker potential than HE in preventing AS development. Their chemical differences might partially explain the discrepancy in their bioactivity. In conclusion, HE and HG might be developed into novel therapeutic agents against inflammation and AS-associated diseases.

In vitro Antioxidant Activity of Artemisia argyi Powder and the Effect on Hepatic and Intestinal Antioxidant Indices in Broiler Chickens

This study was conducted to investigate the in vitro and in vivo antioxidant effect of Artemisia argyi powder (AAP). 240 mixed-sex one-day-old Arbor Acres broilers were randomly divided into five treatment groups, each consisting of six replicates (one replicate per cage) with eight broilers per replicate. Broilers were fed basal diets supplemented with 0, 2.5, 5, 10 and 20 g AAP per kg feed, respectively. The hepatic and intestinal samples were collected on d 21 and 42 for analysis of antioxidant indices and antioxidative enzyme gene expression. The in vitro results showed that the scavenging activity of Artemisia argyi against •OH and DPPH were 34.99±1.11% and 74.12±0.50%, respectively; the ferric reducing power was 2.58±0.03%. The in vivo results showed that dietary 20 g/kg of AAP significantly enhanced the hepatic total antioxidant capacity (T-AOC), catalase (CAT) activity, and glutathione peroxidase (GSH-Px) activity, also decreased the malondialdehyde (MDA) content; dietary10 g/kg of AAP significantly increased the gene expression of superoxide dismutase (SOD) and CAT on d 42. For the duodenum, 10 g/kg of AAP increased SOD activity (P<0.05), and reduced MDA level (P<0.05) on d 21; the gene expression of CAT and SOD were increased in the 20 g/kg of AAP treatment compared with the control group on d 42. For the jejunum, on d 21, the T-AOC level was increased by inclusion of 10 g/kg of AAP, and CAT activity was enhanced significantly at 5, 10, and 20 g/kg of AAP group; dietary AAP significantly decreased MDA level at the concentration of 2.5, 5, 10 and 20 g/kg in contrast with control group on d 42; 5 and 20 g/kg of AAP increased the gene expression of SOD on d 21, and the gene expression of GSH-Px was increased (P<0.05) in 10 g/kg of AAP group on d 42. For the ileum, compared to the control group, 2.5 and 20 g/kg of AAP increased SOD activity (P<0.05); and dietary 10 and 20 g/kg of AAP significantly reduced MDA level; dietary 10 g/kg of AAP increased the gene expression of SOD, CAT and GSH-Px in broilers on d 42. In conclusion, dietary AAP could improve the antioxidant defenses of liver and small intestine, and the best concentration of the AAP improving hepatic and small intestinal antioxidant status was 20 g/kg and 10 g/kg, respectively.

Systematic Detection and Identification of Bioactive Ingredients from Citrus aurantium L. var. amara Using HPLC-Q-TOF-MS Combined with a Screening Method

Bitter orange, Citrus aurantium L. var. amara (CAVA), is an important crop and its flowers and fruits are widely used in China as a food spice, as well as in traditional Chinese medicine, due to its health-promoting properties. The secondary metabolites that are present in plant-derived foods or medicines are, in part, responsible for the health benefits and desirable flavor profiles. Nevertheless, detailed information about the bioactive ingredients in CAVA is scarce. Therefore, this study was aimed at exploring the phytochemicals of CAVA by high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS). Here, a systematic screening method combined with HPLC-Q-TOF-MS was presented. This technique was used to systematically screen metabolites, primarily from the complex matrix of CAVA, and to identify these compounds by their exact masses, characteristic fragment ions, and fragmentation behaviors. A total of 295 metabolites were screened by the screening method and 89 phytochemicals were identified in the flowers, fruits, roots, leaves, and branches of CAVA. For the first time, 69 phytochemicals (flavonoids, alkaloids, terpenoids, etc.) were reported from CAVA. The results highlight the importance of CAVA as a source of secondary metabolites in the food, medicine, and nutraceutical industries.

Optimization of Ultrasonic-Assisted Extraction of Total Phenolics from Citrus aurantium L. Blossoms and Evaluation of Free Radical Scavenging, Anti-HMG-CoA Reductase Activities

The objective of this study was to develop an ultrasonic-assisted procedure for the extraction of total phenolics from Citrus aurantium L. blossoms (CAB) and evaluate the free radical scavenging activity and anti-HMG-CoA reductase activity of the total phenolics. In this work, a Box-&nbsp;Behnken design based on single-factor experiments was used to explore the optimum extraction process. Under the optimum conditions (extraction solvent 70.31% ethanol, extraction temperature 61.94 °C, extraction time 51.73 min, and liquid-to-solid ratio 35.63 mL/g), the extraction yield of total phenolics was 95.84 mg gallic acid equivalents (GAE)/g dry matter (DM), which was highly consistent with the theoretical value (96.12 mg GAE/g DM). The higher contents of total phenolics and five main phenolic compounds obtained from the optimized ultrasonic-assisted extraction (UAE) proved its efficiency when compared with conventional heat reflux extraction (HRE). The total phenolic extract showed excellent free radical scavenging properties against 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·), 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS⁺·), hydroxyl radical (·OH) and superoxide anion radical (·O₂^-), with IC₅₀ values of 197.007, 83.878, 218.643, and 158.885 μg/mL, respectively; the extracts also showed good inhibition of β-hydroxy-β-methylglutaryl-CoA reductase (HMG-CoA reductase) activity, with an IC₅₀ value of 117.165 μg/mL. Total phenolics from CAB could be a potential source of natural free radical scavenger and HMG-CoA reductase inhibitor.

Anti-fatigue Effects of Active Ingredients from Traditional Chinese Medicine: A Review

Background:

The application of traditional Chinese medicine (TCM) in the treatment of fatigue has long been practiced in clinical and showed significant effects.

Objective:

This article summarizes the work done on the natural products from TCM that are reported to have effects of treating fatigue, in the past two decades.

Method:

Research status, sources, models, efficacy and mechanisms of active ingredients and their monomer in the treatment of fatigue are discussed.

Results:

Pharmacological research shows that active ingredients of polysaccharide can significantly improve body’s resistance through promoting glycogen synthesis, reducing sports metabolites and increasing hypoxia tolerance; Alkaloids have been proven to be effective in promoting the reserving of various glucogen substances, improving exercise endurance and speeding up the metabolism of body’s urea nitrogen in mice; With the increase of glycosides amount, up goes the sport endurance, liver glycogen content and the ability of clear lactate index in mice, indicating that saponin has clear, dose-dependent anti-fatigue effect; Polyphenols have also functions of resisting fatigue, where they reduce free radicals accumulated and thus slow down the rapid declination of exercise capacity when doing sports; There are other active ingredients of TCM that have biological activities, like some proteins, anthraquinones, terpenes, unsaturated fatty acid monomer compounds; And research has found that tonic medicine can promote the elimination of fatigue and improve athletic ability.

Conclusion:

It is hoped that the data summarized in this review will be beneficial to the screening of new nature-derived drugs with the ability of relieving and improving fatigue.

Enzymatic Extraction, Purification, and Characterization of Polysaccharides from Penthorum chinense Pursh: Natural Antioxidant and Anti-Inflammatory

Penthorum chinense Pursh (PCP) is a kind of functional food or medicine for liver protection. In the present work, Plackett-Burman design, steepest ascent method, and response surface methodology (RSM) were employed to obtain maximum total sugar yield. The experimental yield of 6.91% indicated a close agreement with the predicted yield of 7.00% of the model under optimized conditions. The major polysaccharide fraction (PCPP-1a) from PCPP was purified and identified as acidic polysaccharides with a high content of uronic acid (FT-IR, UV, HPGPC). PCPP had similar monosaccharide profile with PCPP-1a but was rich in galacturonic acid (HPLC). Both of PCPP and PCPP-1a possessed strong hydroxyl radical scavenging, DPPH radical scavenging, and Fe²⁺ chelating activities. Moreover, they were revealed to show strong anti-inflammatory activities by inhibiting NO, TNF-α, and IL-1β release compared to LPS treatment in RAW264.7 cells. These data suggest that the polysaccharides from PCP could be potential natural products for treating ROS and inflammatory-related diseases.

Polyphenols from Blossoms of Citrus aurantium L. var. amara Engl. Show Significant Anti-Complement and Anti-Inflammatory Effects

Citrus aurantium L. var. amara Engl. (CAVA) was traditionally used as a digestant or expectorant in China. Crude polyphenols (CAVAP-W) extracted from blossoms of CAVA were mainly composed of eriocitrin/neoeriocitrin, eriocitrin/neoeriocitrin, rhoifolin, hesperidin, naringin, rutin, veronicastroside, neohesperidin, and hesperetin by LC-MS analysis. CAVAP-W showed significant anticomplement and anti-inflammatory effects. Due to the close relationship between anticomplement and anti-inflammatory activity, the anti-inflammatory effect was further investigated and the results showed that CAVAP-W significantly suppressed production of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and mRNA expression of inducible nitric oxide synthase (iNOS), IL-6, TNF-α, IL-1β, and cyclooxygenase-2 (COX-2) in lipopolysaccharides-stimulated RAW264.7 cells. Furthermore, CAVAP-W inhibited mitogen-activated protein kinase (MAPK) phosphorylation and NF-κB activation through suppressing nuclear translocation of nuclear factor-kappa B (NF-κB) P65, degradation and phosphorylation of IκBα, phosphorylation of IκKα/ß, c-Jun N-terminal kinase (JNK), and P38, and activation of COX-2, thereby exerting the anti-inflammatory effects.

Anti-inflammatory Effect of Essential Oil from Citrus aurantium L. var. amara Engl

Essential oil has been popularly used as an alternative for the treatment of inflammation. The bioactivities of essential oil from blossoms of Citrus aurantium L. var. amara Engl (CAVAO) showed greater anti-inflammation potential than that of antioxidant, anticancer, and 3T3-L1 proliferation inhibition. CAVAO (250 μg/mL) significantly inhibited production of nitric oxide (NO) (99.54 ± 2.81%), interleukin-6 (IL-6) (98.11 ± 1.62%), tumor necrosis factor-α (TNF-α) (41.84 ± 1.52%), and interleukin-1β (IL-1β) (56.09 ± 2.21%) as well as their gene expression level. CAVAO also markedly decreased the expression levels of cyclooxygenase-2 (COX-2) gene and protein. Furthermore, CAVAO inhibited nuclear factor-κB (NF-κB) activation, which was justified by the inhibitory effect on NF-κB nuclear translocation, IκBα phosphorylation and degradation, and phosphorylation-dependent IκB kinase activation in RAW264.7 cells stimulated with lipopolysaccharides. CAVAO also suppressed the phosphorylation of c-Jun N-terminal kinase (JNK) and p38, indicating that mitogen-activated protein kinase (MAPK) signaling pathways were also blocked. The major constituents of CAVAO were characterized as linalool (64.6 ± 0.04%), α-terpineol (7.61 ± 0.03%), (R)-limonene (6.15 ± 0.04%), and linalyl acetate (5.02 ± 0.03%), which might be responsible for its observed anti-inflammation activity. It is concluded that CAVAO has great potential to be developed into a functional food for the treatment of inflammatory-associated diseases.