Narirutin fraction from citrus peels attenuates LPS-stimulated inflammatory response through inhibition of NF-κB and MAPKs activation

Phytoconstituents as modulator of inflammatory pathways for COVID-19: A comprehensive review and recommendations

SARS-CoV-2 infection causes disruptions in inflammatory pathways, which fundamentally contribute to COVID-19 pathophysiology. The present review critically evaluates the gaps in scientific literature and presents the current status regarding the inflammatory signaling pathways in COVID-19. We propose that phytoconstituents can be used to treat COVID-19 associated inflammation, several already formulated in traditional medications. For this purpose, extensive literature analysis was conducted in the PubMed database to collect relevant in vitro, in vivo, and human patient studies where inflammation pathways were shown to be upregulated in COVID-19. Parallelly, scientific literature was screened for phytoconstituents with known cellular mechanisms implicated for inflammation or COVID-19 associated inflammation. Studies with insufficient evidence on cellular pathways for autophagy and mitophagy were considered out of scope and excluded from the study. The final analysis was visualized in figures and evaluated for accuracy. Our findings demonstrate the frequent participation of NF-κB, a transcription factor, in inflammatory signaling pathways linked to COVID-19. Moreover, the MAPK signaling pathway is also implicated in producing inflammatory molecules. Furthermore, it was also analyzed that the phytoconstituents with flavonoid and phenolic backbones could inhibit either the TLR4 receptor or its consecutive signaling molecules, thereby, decreasing NF-κB activity and suppressing cytokine production. Although, allopathy has treated the early phase of COVID-19, anti-inflammatory phytoconstituents and existing ayurvedic formulations may act on the COVID-19 associated inflammatory pathways and provide an additional treatment strategy. Therefore, we recommend the usage of flavonoids and phenolic phytoconstituents for the treatment of inflammation associated with COVID-19 infection and similar viral ailments.

A mechanistic review of the pharmacological potential of narirutin: a dietary flavonoid

Flavanones, a type of polyphenol, are found in substantial amounts in citrus fruits. When high- or moderate-dose orange juice consumption occurs, flavanones make up a significant portion of the total polyphenols in plasma. Disaccharide derivative narirutin, mainly dihydroxy flavanone, is found in citrus fruits. The substantial chemotherapeutic potential of narirutin has been amply demonstrated by numerous experimental studies. Consequently, the purpose of this study is to compile the research that has already been done showing narirutin to be a promising anticancer drug, with its mechanism of action being documented in treatment plans for various cancer forms. Narirutin functions in a variety of cancer cells by regulating several pathways that include cell cycle arrest, apoptosis, antiangiogenic, antimetastatic, and DNA repair. Narirutin has been shown to modify many molecular targets linked to the development of cancer, including drug transporters, cell cycle mediators, transcription factors, reactive oxygen species, reactive nitrogen species, and inflammatory cytokines. Taken together, these reviews offer important new information about narirutin's potential as a potent and promising drug candidate for use in medicines, functional foods, dietary supplements, nutraceuticals, and other products targeted at improving the treatment of cancer.

Narirutin-Rich Celluclast Extract from Mandarin (Citrus unshiu) Peel Alleviates High-Fat Diet-Induced Obesity and Promotes Energy Metabolism in C57BL/6 Mice

Mandarin peel, a main by-product from the processing of citrus juice, has been highlighted for its various bioactivities and functional ingredients. Our previous study proved the inhibitory effects of Celluclast extract from mandarin peel (MPCE) on lipid accumulation and differentiation in 3T3-L1 adipocytes. Therefore, the current study aimed to evaluate the anti-obesity effect of MPCE in high-fat diet (HFD)-induced obese mice. The high-performance liquid chromatography (HPLC) analysis exhibited that narirutin and hesperidin are the main active components of MPCE. Our current results showed that MPCE supplementation decreased adiposity by reducing body and organ weights in HFD-induced obese mice. MPCE also reduced triglyceride (TG), alanine transaminase (ALT), aspartate transaminase (AST), and leptin contents in the serum of HFD-fed mice. Moreover, MPCE significantly inhibited hepatic lipid accumulation by regulating the expression levels of proteins associated with lipid metabolism, including sterol regulatory element-binding protein (SREBP1c), fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC). Furthermore, MPCE administration significantly inhibited both adipogenesis and lipogenesis, with modulation of energy metabolism by activating 5' adenosine monophosphate-activated protein kinase (AMPK) and lipolytic enzymes such as hormone-sensitive lipase (HSL) in the white adipose tissue (WAT). Altogether, our findings indicate that MPCE improves HFD-induced obesity and can be used as a curative agent in pharmaceuticals and nutraceuticals to alleviate obesity and related disorders.

Narirutin Attenuates Cerebral Ischemia-Reperfusion Injury by Suppressing the TXNIP/NLRP3 Pathway

Narirutin (Nar) is a flavonoid that is abundantly present in citrus fruits and has attracted considerable attention because of its diverse pharmacological activities and low toxicity. Here, we evaluated the preventive effects of Nar in middle cerebral artery occlusion/reperfusion (MCAO/R)-injured mice and oxygen-glucose deprivation/reperfusion (OGD/R)-injured bEnd.3 cells. Pretreatment with Nar (150 mg/kg) for 7 days effectively reduced infarct volume, improved neurological deficits, and significantly inhibited neuronal death in the hippocampus and cortex in MCAO/R-injured mice. Moreover, anti-apoptotic effects of Nar (50 µM) were observed in OGD/R-injured bEnd.3 cells. In addition, Nar pre-administration regulated blood-brain barrier function by increasing tight junction-related protein expression after MCAO/R and OGD/R injury. Nar also inhibited NOD-like receptor protein 3 (NLRP3) inflammasome activation by reducing the expression of thioredoxin-interacting protein (TXNIP) in vivo and in vitro. Taken together, these results provide new evidence for the use of Nar in the prevention and treatment of ischemic stroke.

Synthesis and biological evaluation of chromanone-based derivatives as potential anti-neuroinflammatory agents

As a privileged scaffold, chromanone has been extensively introduced in the design of drug leads with diverse pharmacological features, particularly in the area of inflammatory diseases. Herein, the preparation of chromanone-based derivatives (4a-4i) was smoothly achieved, and their structures were characterized using 1H NMR, 13C NMR, and ESI-HRMS spectroscopy techniques. Out of them, analogue 4e exhibited the most potent inhibitory capacity against the NO release and iNOS expression, without apparent cytotoxicity. Our observations showed that 4e could dramatically prevent the translocation of NF-κB from the cytoplasm to nucleus, and decrease the production of proinflammatory cytokines TNF-α, IL-6 and IL-1β in LPS-induced BV-2 cells. Mechanistically, 4e significantly deactivated NF-κB by disturbing TLR4-mediated TAK1/NF-κB and PI3K/Akt signaling cascades. Consistent with the in vitro study, 4e could effectively mitigate the inflammation response of hippocampal tissue in LPS-induced mouse model by inhibiting microglial activation. Collectively, these results revealed 4e as a prospective neuroprotective candidate for the therapy of neuroinflammation-related disorders.

The association between adherence to diet quality index and cardiometabolic risk factors in overweight and obese women: a cross-sectional study

Background

Obesity and overweight status increase the risk of cardiovascular disease. Diet quality can also predict the risk of cardiovascular diseases in obese and overweight patients. Therefore, in this study, we sought to examine the relationship between diet quality index (DQI) and cardiometabolic risk factors in obese and overweight women.

Method

A cross-sectional study was conducted on 197 Iranian women with a Body Mass Index (BMI) > 25, 18-48 years, and recruited from 20 Tehran Health Centers. Nutrition intake and DQI were assessed using a 147-item semi-quantitative food frequency questionnaire (FFQ). Additionally, anthropometric measurements, body composition, biochemical evaluations, and cardiometabolic risk factors were evaluated.

Results

There was an association between DQI and waist-to-hip ratio (WHR), atherogenic index of plasma (AIP), and CHOLINDEX in obese women, after adjusting for potential confounders. Whereas, there were no significant associations of the tertiles of DQI compared with the first tertile in other cardiometabolic risk factors, before and after adjustment.

Conclusion

This study provides evidence that dietary intake and DQI are associated with cardiometabolic risk factors and that dietary modification may be a predictor for reducing WHR, AIP, and CHOLINDEX. However, more research is needed to develop a DQI that reflects changes in cardiometabolic risk factors by considering women's eating habits and patterns.

Citrus tangerine pith extract alleviates hypoxia-induced ileum damage in mice by modulating intestinal microbiota

Visitors to high altitude are susceptible to hypoxia-induced acute intestinal mucosal barrier injury and severe gastrointestinal disorders, which are life-threatening. Citrus tangerine pith extract (CTPE) is rich in pectin and flavonoids and has been proved to enhance intestinal health and improve gut dysbiosis. In this study, we aim to explore the protective effect of CTPE on ileum injury induced by intermittent hypobaric hypoxia in a mouse model. Balb/c mice were divided into blank normoxia (BN), blank hypobaric hypoxia (BH), hypobaric hypoxia plus CTPE (TH), and hypobaric hypoxia plus Rhodiola extract (RH) groups. From the 6th day of gavage, mice in BH, TH, and RH groups were transferred into a hypobaric chamber at a simulated elevation of 6000 m for 8 hours per day for 10 days. Then half the mice were tested for small intestine movement, and others were used to evaluate intestinal physical barrier function, inflammation, and gut microbiota. Results showed that CTPE reversed the increase of intestinal peristalsis, effectively attenuated impaired structural integrity of ileum, improved the mRNA and protein expression levels of tight junction proteins, and reduced serum D-LA content in mice to alleviate hypoxia-induced mucosal barrier damage. Moreover, CTPE supplementation ameliorated hypoxia-induced intestinal inflammation response by significantly downregulating the proinflammatory cytokines IL-6, TNF-α and IFN-γ. By 16S rDNA gene sequencing of gut microbiota, CTPE significantly increased the abundance of probiotic Lactobacillus, suggesting that CTPE may be used as a prebiotic to regulate ecology of intestinal microorganisms. In addition, Spearman rank correlation analysis revealed that changed gut microbiota were significantly correlated with alteration of intestinal barrier function indexes. Taken together, these results indicate that CTPE effectively alleviates hypoxia-induced intestinal injury in mice and enhances intestinal integrity and barrier function by altering intestinal microbiota composition.

Narirutin downregulates lipoxygenase-5 expression and induces G0/G1 arrest in triple-negative breast carcinoma cells

BACKGROUND

Triple-negative breast cancer (TNBC) accounts for 20% of breast cancer that does not express HER2, progesterone and estrogen receptors. It is associated with a high mortality rate, morbidity, metastasis, recurrence, poor prognosis and resistance to chemotherapy. Lipoxygenase-5 (LOX-5), cyclooxygenase-2 (COX-2), cathepsin-D (CATD), ornithine decarboxylase (ODC) and dihydrofolate reductase (DHFR) are involved in breast cancer carcinogenesis; hence, there is a pressing need to identify novel chemicals that targets these enzymes. Narirutin, a flavanone glycoside abundantly present in citrus fruits, is reported to have immune-modulatory, anti-allergic and antioxidant potential. Still, the cancer chemopreventive mechanism against TNBC has not been explored.

METHODS

In vitro experiments, enzyme activity, expression analysis, molecular docking and MD simulation were carried out.

RESULTS

Narirutin suppressed the growth of MDA-MB-231 and MCF-7 in a dose-proportional manner. The pronounced effect with >50% inhibition was observed in SRB and MTT assays for MDAMB-231 cells. Unexpectedly, narirutin suppressed the proliferation of normal cells (24.51%) at 100 μM. Further, narirutin inhibits the activity of LOX-5 in cell-free (18.18 ± 3.93 μM) and cell-based (48.13 ± 7.04 μM) test systems while moderately affecting COX-2, CATD, ODC and DHFR activity. Moreover, narirutin revealed a down-regulation of LOX-5 expression with a fold change of 1.23. Besides, MD simulation experiments confirm that narirutin binding forms a stable complex with LOX-5 and improves the stability and compactness of LOX-5. In addition, the prediction analysis demonstrates that narirutin could not cross the blood-brain barrier and did not act as an inhibitor of different CYPs.

CONCLUSIONS AND SIGNIFICANCE

Narirutin could be a potent cancer chemopreventive lead for TNBC, further paving the way for synthesizing novel analogues.

Antioxidant and Anti-Inflammatory Compounds from Edible Plants with Anti-Cancer Activity and Their Potential Use as Drugs

Food is our daily companion, performing numerous beneficial functions for our bodies. Many of them can help to alleviate or prevent ailments and diseases. In this review, an extensive bibliographic search is conducted in various databases to update information on unprocessed foods with anti-inflammatory and antioxidant properties that can aid in treating diseases such as cancer. The current state of knowledge on inflammatory processes involving some interleukins and tumor necrosis factor-alpha (TNF-α) is reviewed. As well as unprocessed foods, which may help reduce inflammation and oxidative stress, both of which are important factors in cancer development. Many studies are still needed to take full advantage of the food products we use daily.

Citrus peel ameliorates mucus barrier damage in HFD-fed mice

Citrus peel is rich in bioactive components, especially polyphenols, which are considered to have great potential in the prevention of intestinal diseases. The intestinal mucus barrier is the first defense against the invasion of foreign substances. In this study, we aimed to explore the possibility and mechanism of citrus peel in alleviating the mucus barrier damage in high-fat-diet (HFD) mice. We found that citrus peel powder (CPP) supplementation effectively reduced body weight, fat weight, intestinal permeability, hyperlipidemia, and systemic inflammation in HFD-fed mice. In particular, CPP increased the number of goblet cells, the protein expression of Mucin-2 (Muc2), and the thickness of the mucus layer, thereby strengthening the colonic mucus barrier function. Moreover, CPP supplementation also reduced the expression of endoplasmic reticulum stress (ERS) proteins (GRP78 and CHOP) and increased the expression of T-synthase (O-glycosylation rate-limiting enzyme) and its chaperone protein (Cosmc) in the colon of HFD-fed mice, which suggested that CPP could improve the abnormal protein folding and O-glycosylation of Muc2 during processing and modification. In summary, our study indicates that CPP plays an effective role in relieving mucus barrier damage by improving the production and properties of Muc2, providing new perspectives on the development of CPP as a dietary supplement for strengthening the intestinal barrier.

Chiral Separation, Configuration Confirmation and Bioactivity Determination of the Stereoisomers of Hesperidin and Narirutin in Citrus reticulata Blanco

Hesperidin and narirutin are a class of flavanone glycosides, which are the main active constituents in Citrus reticulata Blanco. In the present study, a chiral HPLC-UV method with amylose tris(3,5-dimethylphenylcarbamate) as a stationary phase under a normal-phase mode was used to achieve the stereoselective separation of the C-2 diastereomers of hesperidin and narirutin simultaneously. The single epimer was then successfully prepared by applying semi-preparative chromatography, whose absolute configuration (R/S) was characterized by combining the experimental electronic circular dichroism (ECD) detection with time-dependent density functional theory (TDDFT) calculations. The epimer composition of these two chiral flavanone glycosides in Citrus reticulata Blanco was then determined, which was found to be slightly different in the herbs from different production regions. The anti-inflammatory activity of each prepared single epimer was further evaluated, and some differences between one pair of epimers of hesperidin and narirutin were observed, which suggested that the presence of different epimers should be considered in the quality evaluation and control of natural medicine.

Casein Lactose-Glycation of the Maillard-Type Attenuates the Anti-Inflammatory Potential of Casein Hydrolysate to IEC-6 Cells with Lipopolysaccharide Stimulation

During the thermal processing of dairy products, the Maillard reaction occurs between milk proteins and lactose, resulting in the formation of various products including glycated proteins. In this study, lactose-glycated casein was generated through the Maillard reaction between casein and lactose and then hydrolyzed by a trypsin preparation. The anti-inflammatory effect of the resultant glycated casein hydrolysate (GCH) was investigated using the lipopolysaccharide (LPS)-sitmulated rat intestinal epithelial (IEC-6) cells as a cell model and corresponding casein hydrolysate (CH) as a control. The results indicated that the preformed glycation enabled lactose conjugation to casein, which endowed GCH with a lactose content of 12.61 g/kg protein together with a lower activity than CH to enhance the viability value of the IEC-6 cells. The cells with LPS stimulation showed significant inflammatory responses, while a pre-treatment of the cells with GCH before LPS stimulation consistently led to a decreased secretion of three pro-inflammatory mediators, namely, IL-6, IL-1β and tumor necrosis factor-α (TNF-α) but an increased secretion of two anti-inflammatory mediators, including IL-10 and transforming growth factor-β (TGF-β), demonstrating the anti-inflammatory potential of GCH in LPS-stimulated cells. In addition, GCH up-regulated the expression of TLR4, p-p38, and p-p65 proteins in the stimulated cells, resulting in the suppression of NF-κB and MAPK signaling pathways. Collectively, GCH was mostly less efficient than CH to exert these assessed anti-inflammatory activities in the cells and more importantly, GCH also showed an ability to cause cell inflammation by promoting IL-6 secretion and up-regulating the expression of TLR4 and p-p65. The casein lactose-glycation of the Maillard-type was thereby concluded to attenuate the anti-inflammatory potential of the resultant casein hydrolysate. It is highlighted that the casein lactose-glycation of the Maillard-type might cause a negative impact on the bioactivity of casein in the intestine, because the glycated casein after digestion could release GCH with reduced anti-inflammatory activity.

Reversal of Peripheral Neuropathic Pain by the Small-Molecule Natural Product Narirutin via Block of Nav1.7 Voltage-Gated Sodium Channel

Neuropathic pain is a refractory chronic disease affecting millions of people worldwide. Given that present painkillers have poor efficacy or severe side effects, developing novel analgesics is badly needed. The multiplex structure of active ingredients isolated from natural products provides a new source for phytochemical compound synthesis. Here, we identified a natural product, Narirutin, a flavonoid compound isolated from the Citrus unshiu, showing antinociceptive effects in rodent models of neuropathic pain. Using calcium imaging, whole-cell electrophysiology, western blotting, and immunofluorescence, we uncovered a molecular target for Narirutin's antinociceptive actions. We found that Narirutin (i) inhibits Veratridine-triggered nociceptor activities in L4-L6 rat dorsal root ganglion (DRG) neurons, (ii) blocks voltage-gated sodium (Na_V) channels subtype 1.7 in both small-diameter DRG nociceptive neurons and human embryonic kidney (HEK) 293 cell line, (iii) does not affect tetrodotoxin-resistant (TTX-R) Na_V channels, and (iv) blunts the upregulation of Na_v1.7 in calcitonin gene-related peptide (CGRP)-labeled DRG sensory neurons after spared nerve injury (SNI) surgery. Identifying Na_v1.7 as a molecular target of Narirutin may further clarify the analgesic mechanism of natural flavonoid compounds and provide an optimal idea to produce novel selective and efficient analgesic drugs.

Citrus junos Tanaka Peel Extract Ameliorates HDM-Induced Lung Inflammation and Immune Responses In Vivo

In the wake of the COVID-19 pandemic, lung disorders have become a major health concern for humans. Allergic asthma is the most prevalent form of asthma, and its treatments target the inflammation process. Despite significant developments in the diagnosis and management of allergic asthma, side effects are a major concern. Additionally, its extreme heterogeneity impedes the efficacy of the majority of treatments. Thus, newer, safer therapeutic substances, such as natural products, are desired. Citrus junos Tanaka has traditionally been utilized as an anti-inflammatory, sedative, antipyretic, and antitoxic substance. In this study, the protective effects of Citrus junos Tanaka peel extract (B215) against lung inflammation were examined, and efforts were made to understand the underlying protective mechanism using an HDM-induced lung inflammation murine model. The administration of B215 reduced immune cell infiltration in the lungs, plasma IgE levels, airway resistance, mucus hypersecretions, and cytokine production. These favorable effects alleviated HDM-induced lung inflammation by modulating the NF-κB signaling pathway. Hence, B215 might be a promising functional food to treat lung inflammation without adverse effects.

The recovery from agro-industrial wastes provides different profiles of anti-inflammatory polyphenols for tailored applications

Food and agro-industrial processing produce a great amount of side-stream and waste materials that are excellent sources of functional bioactive molecules such as phenolic compounds that recover them can be beneficial not only for food sustainability but also to human for many industrial applications such as flavor compounds and therapeutic applications such as antimicrobial and anti-inflammatory. The treatments and extraction techniques have major effects on the recovery of bioactive compounds. Along with the conventional extraction methods, numerous innovative techniques have been evolved and have been optimized to facilitate bioactive extraction more efficiently and sustainably. In this work, we have summarized the state-of-the-art technological approaches concerning novel extraction methods applied for five most produced crops in Italy; Grape Pomace (GP), Tomato Pomace (TP), Olive Pomace (OP), Citrus Pomace (CP), and Spent Coffee Grounds (SCG), presenting the extraction yield and the main class of phenolic classes, with the focus on their biological activity as an anti-inflammatory in vitro and in vivo studies via describing their molecular mechanism of action.

Oral Intervention of Narirutin Ameliorates the Allergic Response of Ovalbumin Allergy

A new intervention was investigated for the induction of oral tolerance (OT) of OVA using narirutin by in vivo and in vitro experiments combined with network pharmacology and structural analysis of molecular docking. Narirutin (and its metabolism naringenin) has effects on OT by affecting B cell function, DCs, and T cell response by prediction. It was verified that narirutin could affect B cell function of secreting antibodies, thereby reducing the ability of DCs to absorb antigens by affecting GATA3, CCR7, STAT5, and MHCII expression and regulating T cell response by suppressing Th2 and improving Treg cells in vivo. Molecular docking showed that steric hindrance effects may be the reason for weaker binding energy with targets of narirutin. However, this does not mean that it has no bioactivity, for it can inhibit mast cell degranulation. This finding is interesting because it offers the possibility of using natural compounds to promote oral tolerance.

Pharmacological Effects of Polyphenol Phytochemicals on the Intestinal Inflammation via Targeting TLR4/NF-κB Signaling Pathway

TLR4/NF-κB is a key inflammatory signaling transduction pathway, closely involved in cell differentiation, proliferation, apoptosis, and pro-inflammatory response. Toll like receptor 4 (TLR4), the first mammalian TLR to be characterized, is the innate immune receptor that plays a key role in inflammatory signal transductions. Nuclear factor kappa B (NF-κB), the TLR4 downstream, is the key to accounting for the expression of multiple genes involved in inflammatory responses, such as pro-inflammatory cytokines. Inflammatory bowel disease (IBD) in humans is a chronic inflammatory disease with high incidence and prevalence worldwide. Targeting the TLR4/NF-κB signaling pathway might be an effective strategy to alleviate intestinal inflammation. Polyphenol phytochemicals have shown noticeable alleviative effects by acting on the TLR4/NF-κB signaling pathway in intestinal inflammation. This review summarizes the pharmacological effects of more than 20 kinds of polyphenols on intestinal inflammation via targeting the TLR4/NF-κB signaling pathway. We expected that polyphenol phytochemicals targeting the TLR4/NF-κB signaling pathway might be an effective approach to treat IBD in future clinical research applications.

Prospective multifunctional roles and pharmacological potential of dietary flavonoid narirutin

Plant-based phytochemicals are now being used to treat plenty of physiological diseases. Herbal drugs have gained popularity in recent years because of their strength, purity, and cheap cost-effectiveness. Citrus fruits contain significant amounts of flavanones, which falls to the category of polyphenols. Flavanones occupy a major fraction of the total polyphenols present in the plasma when orange juice is taken highly or in moderate states. Narirutin is a disaccharide derivative available in citrus fruits, primarily dihydroxy flavanone. From a pharmacological viewpoint, narirutin is a bioactive phytochemical with therapeutic efficacy. Many experimental researches were published on the use of narirutin. Anticancer activity, neuroprotection, stress relief, hepatoprotection, anti-allergic activity, antidiabetic activity, anti-adipogenic activity, anti-obesity action, and immunomodulation are a couple of the primary pharmacological properties. Narirutin also has antioxidant, and anti-inflammatory activities. The ultimate goal of this review is to provide the current scenario of pharmacological research with narirutin; to make a better understanding for therapeutic potential of narirutin, as well as its biosynthesis strategies and side effects. Extensive literature searches and studies were undertaken to determine the pharmacological properties of narirutin.

Analyses of Physical and Chemical Compositions of Different Medicinal Specifications of CRPV by Use of Multiple Instrumental Techniques Combined with Multivariate Statistical Analysis

Citri Reticulatae Pericarpium Viride (CRPV) is the processed product of Citrus reticulata Blanco. We systematically analyzed two CRPV types, Geqingpi (GQP) and Sihuaqingpi (SHQP), based on powder color, microscopic characteristics, and chemical composition. In addition, we characterized their constituents via ultra-high-performance liquid chromatography with hybrid quadrupole-orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap-MS). Both showed significant differences in their powder color and microscopic characteristics. Fourier-transform infrared (FT-IR) spectroscopic analysis results showed that the C=O peak absorption of carboxylic acids and their carbonyl esters in SHQP was higher than that of GQP, while the C-OH and C-H plane bending peaks of polysaccharides were lower than those of GQP. We analyzed these data via similarity analysis, PCA, and OPLS-DA. GQP and SHQP had large distinct differences. Based on the mass measurements for molecular and characteristic fragment ions, we identified 44 main constituents from CRPV, including different flavonoid glycosides and flavonoid aglycones in SHQP and GQP, respectively. We found luteolin-6-C-glucoside, orientin, rhoifolin, and pilloin solely in SHQP, and naringenin and hesperetin only in GQP. The peak area measurements showed GQP having a higher flavonoid glycoside (narirutin, hesperidin, etc.) content, whereas SHQP had a higher polymethoxyflavone (nobiletin, tangeretin, etc.) content. Since we holistically analyzed two CRPV types, the results can not only support future pharmacological research, but also provide a scientific basis for formulating more reasonable CRPV quality standards and guide its clinical potential as a precision medicine.

Recent advances in valorization of citrus fruits processing waste: a way forward towards environmental sustainability

Citrus fruits are well known for their medicinal and therapeutic potential due to the presence of immense bioactive components. With the enormous consumption of citrus juice, citrus processing industries are focused on the production of juice but at the same time, a large amount of waste is produced mainly in the form of peel, seeds, pomace, and wastewater. This waste left after processing leads to environmental pollution and health-related hazards. However, it could be exploited for the recovery of essential oils, pectin, nutraceuticals, macro and micronutrients, ethanol, and biofuel generation. In view of the importance and health benefits of bioactive compounds found in citrus waste, the present review summarizes the recent work done on the citrus fruit waste valorization for recovery of value-added compounds leading to zero wastage. Therefore, instead of calling it waste, these could be a good resource of significant valuable components, in this way encouraging the zero-waste theory.

Analysis and Potential Value of Compounds Extracted From Star Ruby, Rio Red, and Ruby Red Grapefruit, and Grapefruit Juice Processing Residues via Steam Explosion

Culled whole grapefruit (WG) and grapefruit juice processing residues (GP) are currently incorporated into low-cost animal feed. If individual chemical components found within these side streams could be recovered as high-value coproducts, this would improve the overall value of the grapefruit crop. In this study, pectic hydrocolloids, sugars, volatiles, phenolics, and flavonoids were extracted from Star Ruby, Rio Red, and Ruby Red GP and WG using a continuous pilot scale steam explosion system. Up to 97% of grapefruit juice oils and peel oils could be volatilized and contained 87-94% d-limonene. The recovery of pectin, as determined by galacturonic acid content, was between 2.06 and 2.72 g 100 g-1. Of the phenolics and flavonoids analyzed in this study, narirutin and naringin were extracted in the amounts of up to 10,000 and 67,000 μg g-1, respectively.

Relaxation effect of narirutin on rat mesenteric arteries via nitric oxide release and activation of voltage-gated potassium channels

Narirutin is one of the most common flavanones found in citrus fruits. The vascular effects of its analogues naringenin and naringin have been reported but its effects on the cardiovascular system are largely unknown. In this study, relaxation effect of narirutin and its mechanisms of action were investigated by measuring isometric tension in rat mesenteric arteries. Patch-clamping was also used to study the effect of narirutin on potassium channels in vascular smooth muscle cells. Moreover, its effects on phosphorylation of endothelial nitric oxide synthase, cAMP level and phosphodiesterase activity in rat mesenteric arteries were studied by Western blot and biochemical assays. The results showed that pre-incubation of rat mesenteric arteries with narirutin had no influence on acetylcholine-induced endothelial-dependent relaxation. However, narirutin caused a direct concentration-dependent relaxation in rat mesenteric arteries. This relaxation effect was comparable to that of narirutin's structural analogue naringenin. Narirutin-induced relaxation was reduced by the removal of endothelium, NG-nitro-L-arginine methyl ester (a nitric oxide synthase inhibitor), and 4-aminopyridine (a voltage-gated potassium channel blocker). In addition, narirutin increased the phosphorylation of endothelial nitric oxide synthase and increased the voltage-dependent potassium current in mesenteric arterial smooth muscle cells. These effects were abolished by protein kinase A inhibitor. Furthermore, narirutin could increase cAMP level and inhibit phosphodiesterase activity in rat mesenteric arteries. In conclusion, narirutin has vasorelaxing effect and the mechanism involves the inhibition of phosphodiesterase, which increases intracellular cAMP, thereby stimulating the endothelial nitric oxide synthase and activating the voltage-gated potassium channels in vascular smooth muscle cells.

A review of chemical constituents and health-promoting effects of citrus peels

Citrus is one of the main fruits processed worldwide, producing a lot of industrial by-products. As the main part of citrus "residue", citrus peels have a wide application prospect. They could not only be directly used to produce various food products, but also be used as promising biofuels to produce ethanol and methane. Additionally, functional components (flavonoids, limonoids, alkaloids, essential oils and pectin) extracted from citrus peels have been related to the improvement of human health against active oxygen, inflammatory, cancer and metabolic disorders. Therefore, it is clear that the citrus peels have great potential to be developed into useful functional foods, medicines and biofuels. This review systematically summarizes the recent advances in current uses, processing, bioactive components and biological properties of citrus peels. A better understanding of citrus peels may provide reference for making full use of it.

Bioactivity, bioavailability, and gut microbiota transformations of dietary phenolic compounds: implications for COVID-19

The outbreak of mysterious pneumonia at the end of 2019 is associated with widespread research interest worldwide. The coronavirus disease-19 (COVID-19) targets multiple organs through inflammatory, immune, and redox mechanisms, and no effective drug for its prophylaxis or treatment has been identified until now. The use of dietary bioactive compounds, such as phenolic compounds (PC), has emerged as a putative nutritional or therapeutic adjunct approach for COVID-19. In the present study, scientific data on the mechanisms underlying the bioactivity of PC and their usefulness in COVID-19 mitigation are reviewed. In addition, antioxidant, antiviral, anti-inflammatory, and immunomodulatory effects of dietary PC are studied. Moreover, the implications of digestion on the putative benefits of dietary PC against COVID-19 are presented by addressing the bioavailability and biotransformation of PC by the gut microbiota. Lastly, safety issues and possible drug interactions of PC and their implications in COVID-19 therapeutics are discussed.

Anti-Allergic Effects of the Subcritical Water Extract Powder of Citrus unshiu in Mouse and Guinea Pig Models

We evaluated the effects of unripe mandarin orange (Citrus unshiu) extract powder (unripe mandarin extract powder [UMEP]) treated with subcritical water on allergic diseases by using animal models. High performance liquid chromatography (HPLC) analysis revealed that subcritical water is a more effective solvent than alcohol and hot water, as it quickly extracted approximately 90% of the functional compounds narirutin (1) and hesperidin (2) from whole fruits. Repeated oral administration of UMEP significantly reversed the peripheral blood flow decline observed during the promotion of allergies after sensitization with the antigen, hen egg-white lysozyme (HEL). UMEP also significantly inhibited compound 48/80-induced scratching behavior in HEL-sensitized mice, which are more sensitive to itching stimuli than are normal mice, without suppressing locomotor activity. In addition, repeated oral administration of UMEP in ovalbumin-challenged guinea pigs significantly suppressed the late phase of nasal airway resistance. This study provides evidence that the subcritical water extract powder of unripe C. unshiu fruit is an effective anti-allergic functional food.

Effect of Yijin-Tang, an Oriental Traditional Formula, on Allergic Responses Using an Ovalbumin-Induced Murine Asthma Model

Yijin-tang is an oriental traditional herb used to treat inflammatory diseases. In the present study, we investigated the protective effects of Yijin-tang water extract (YTE) using an ovalbumin- (OVA-) induced asthma model, focusing on the antioxidant and anti-inflammatory properties of the herb. BALB/c mice were intraperitoneally injected with OVA on days 0 and 14 and then challenged with OVA on days 21, 22, and 23. The animals were orally administered YTE (200 and 400 mg/kg) from days 18 to 23, and this was found to significantly decrease airway hyperresponsiveness and release of inflammatory cells, cytokines, and OVA-specific immunoglobulin E in mice with asthma. In addition, YTE was associated with a marked reduction in airway inflammation and mucus production in lung tissue of mice with asthma. Furthermore, YTE suppressed the expression of matrix metalloproteinase-9 and phosphorylation of ERK in the lungs, which in turn led to a reduction in inducible nitric oxide synthases and an elevation in reduced glutathione and heme oxygenase-1. In conclusion, YTE effectively suppressed allergic responses in mice with asthma and the effect was closely related to antioxidant and anti-inflammatory properties of the herb. Our results indicate that YTE may be a potential agent for the treatment of allergic asthma.

Pure Total Flavonoids From Citrus Protect Against Nonsteroidal Anti-inflammatory Drug-Induced Small Intestine Injury by Promoting Autophagy in vivo and in vitro

Small intestine injury is an adverse effect of non-steroidal anti-inflammatory drugs (NSAIDs) that urgently needs to be addressed for their safe application. Although pure total flavonoids from citrus (PTFC) have been marketed for the treatment of digestive diseases, their effects on small intestine injury and the underlying mechanism of action remain unknown. This study aimed to investigate the potential role of autophagy in the mechanism of NSAID (diclofenac)-induced intestinal injury in vivo and in vitro and to demonstrate the protective effects of PTFC against NSAID-induced small intestine disease. The results of qRT-PCR, western blotting, and immunohistochemistry showed that the expression levels of autophagy-related 5 (Atg5), light chain 3 (LC3)-II, and tight junction (TJ) proteins ZO-1, claudin-1, and occludin were decreased in rats with NSAID-induced small intestine injury and diclofenac-treated IEC-6 cells compared with the control groups. In the PTFC group, Atg5 and LC3-II expression, TJ protein expression, and the LC3-II/LC3-I ratio increased. Furthermore, the mechanism by which PTFC promotes autophagy in vivo and in vitro was evaluated by western blotting. Expression levels of p-PI3K and p-Akt increased in the intestine disease-induced rat model group compared with the control, but decreased in the PTFC group. Autophagy of IEC-6 cells was upregulated after treatment with a PI3K inhibitor, and the upregulation was significantly more after PTFC treatment, suggesting PTFC promoted autophagy through the PI3K/Akt signaling pathway. In conclusion, PTFC protected intestinal barrier integrity by promoting autophagy, which demonstrates its potential as a therapeutic candidate for NSAID-induced small intestine injury.

Meta-Analysis on the Chinese Herbal Formula Xiaoer-Feike Granules as a Complementary Therapy for Children With Acute Lower Respiratory Infections

Background

Over the past five years the Chinese herbal formula (CHF) medicine, Xiaoer-Feike granules (XFG), has become a widely used adjuvant therapy for acute lower respiratory infections (ALRI). Considering the rapid popularization and application of XFG, and the lack of systematic evidence evaluating its effectiveness and safety in treating ALRI, it is necessary to conduct a meta-analysis to determine its benefits for patients.

Methods

This study systematically identified randomized controlled trials (RCTs) of XFG treatments for ALRI through July 2019 using four English-databases (PubMed, Cochrane Library, Ovid, and Web of Science) and four Chinese-databases (Sino-med database, China National Knowledge Infrastructure (CNKI), VIP database, and the WANFANG database). We then performed a quality assessment and data analysis with Review Manager 5.3.5 and Stata 15.1.

Results

Twenty-one RCTs involving 3425 patients were randomly divided into an XFG group and a conventional medicine (CM) group. The results showed that the clinical efficacy rate (CER) of the XFG group was significantly higher than that of the CM group (RR=1.17, 95% CI =1.13-1.22, P< 0.00001). In comparison with the CM group, the XFG group had strikingly shortened: resolution time of cough (RTC) (MD = -1.92; 95% CI =-2.33, -1.51, P<0.00001); resolution time of rale (RTR) (MD = -1.68; 95% CI =-2.27, -1.10, P<0.00001); resolution time of fever (RTF) (MD = -1.46; 95% CI =-1.92, -1.00, P<0.00001); resolution time of inflammatory lesions (RTIL) (MD = -2.43, 95% CI =-2.94, -1.93, P< 0.00001); and hospital stays (HS) (MD = -2.26, 95% CI =-3.03, -1.49, P< 0.00001). At the cellular and molecular level, the CD4, CD8, CD4/CD8, IL-6, TNF-α, and CRP levels were significantly improved when CM was complemented with XFG. In addition, no significant difference was observed between the XFG and CM groups in terms of the adverse events (AE) (RR =0.97, 95% CI= 0.61-1.54, P= 0.89).

Conclusions

The findings of this meta-analysis support the use of XFG in the treatment of ALRI. However, these results should be treated with caution due to the significant heterogeneity and publication bias of existing data. Further well-designed and high-quality RCTs are needed to interrogate the efficacy and safety of XFG.

Narirutin-rich fraction from grape fruit peel protects against transient cerebral ischemia reperfusion injury in rats

Objective: Ischemic stroke is one of the leading causes of disability in adults worldwide. The present study was aimed to evaluate the efficacy of Narirutin-rich fraction (NRF), obtained from grape fruit peel, on cerebral ischemia/reperfusion injury in rats.Methods: Male Wistar rats (180-200 g) were subjected to bilateral carotid artery occlusion for 30 min followed by reperfusion for 24 h to induce cerebral ischemia/reperfusion injury. NRF (150, 300 mg/kg, oral) was administered for 7 days continuously before animals were subjected to ischemia/reperfusion injury. Various behavioral tests (for measurement of motor coordination, locomotor activity, and spatial memory), biochemical parameters (lipid peroxidation, superoxide dismutase, and catalase activity), and histopathological alterations were assessed.Results: Seven-day NRF (150 and 300 mg/kg) pretreatment significantly improved neurobehavioral alterations and histological findings as compared to the disease control group. Further NRF treatment significantly reduced oxidative damage as indicated by improved lipid peroxidation, superoxide dismutase, and catalase activity as compared to disease control animals.Conclusion: The present study demonstrated the protective effect of NRF against cerebral ischemia/reperfusion injury in rats. The results suggest that NRF can be a potential pretreatment option against cerebral ischemia/reperfusion injury.

Narirutin produces antidepressant-like effects in a chronic unpredictable mild stress mouse model

Depression is a highly debilitating and life-threatening mental disorder, which is accompanied by dysregulation of the peripheral and central immune system. Narirutin (NR), which has antioxidant and anti-inflammatory activities, is one of the active constituents isolated from Citrus unshiu. However, its potential antidepressant-like and anxiolytic-like effects are poorly understood. The present study was aimed to investigate whether NR confers an antidepressant-like effect in mice exposed to a chronic mild stress (CMS) model of depression. The results showed that NR treatment for 1 week significantly alleviated the depressive-like behaviours of CMS-exposed mice, as indicated by restored decreased sucrose preference and shortened floating time in the forced swimming test. Moreover, NR treatment significantly blocked the CMS-induced anxiety-like behaviors, including increased time spent in the central zone in the open field test, and shortened the latency to feeding in the novelty suppressed feeding test. Taken together, our findings suggested that NR exerted potential antidepressant-like and anxiolytic-like effects in CMS mice model of depression, which support further exploration into developing NR as a novel agent to treat depression and even other stress-related disorders.

Polyphenolic Extract from Tarocco (Citrus sinensis L. Osbeck) Clone "Lempso" Exerts Anti-Inflammatory and Antioxidant Effects via NF-kB and Nrf-2 Activation in Murine Macrophages

Citrus fruits are often employed as ingredients for functional drinks. Among Citrus, the variety, “Lempso”, a typical hybrid of the Calabria region (Southern Italy), has been reported to possess superior antioxidant activity when compared to other common Citrus varieties. For these reasons, the aim of this study is to investigate in vitro the nutraceutical value of the Tarocco clone, “Lempso”, highlighting its anti-inflammatory and antioxidant potential. A post-column 2,2′-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging assay for the screening of antioxidant compounds in these complex matrices was developed. Subsequently, polyphenolic extract was tested on a murine macrophage cell line under inflammatory conditions. The extract resulted was able to significantly inhibit nitric oxide (NO) and cytokine release and inducible nitric oxide synthase (iNOS) and cycloxygenase-2 (COX-2) expression. The inhibition of these pro-inflammatory factors was associated to Nuclear factor-kB (NF-kB) inhibition. Our results also indicate an anti-oxidant potential of the extract as evidenced by the inhibition of reactive oxygen species (ROS) release and by the activation of the nuclear factor E2-related factor-2 (Nrf-2) pathway in macrophages. The obtained results highlight the anti-inflammatory and antioxidant potential of Lempso extract and its potential use, as a new ingredient for the formulation of functional beverages with high nutraceutical value, providing health benefits to consumers.

Neuroprotective effect of Citrus kawachiensis (Kawachi Bankan) peels, a rich source of naringin, against global cerebral ischemia/reperfusion injury in mice

Cerebral ischemia/reperfusion is known to induce the generation of reactive oxygen species and inflammatory responses. Numerous studies have demonstrated that naringin (NGIN) has anti-oxidant and anti-inflammatory properties. We previously reported that Citrus kawachiensis contains a large quantity of NGIN in its peel. In the present study, we orally (p.o.) administered dried peel powder of C. kawachiensis to mice of a transient global ischemia model and found in the hippocampus region that it 1) suppressed neuronal cell death, 2) reversed the reduction in the level of phosphorylated calcium-calmodulin-dependent protein kinase II, 3) had the tendency to reverse the reduction in the level of glutathione, and 4) blocked excessive activation of microglia and astrocytes. These results suggested that the dried peel powder of C. kawachiensis had a neuroprotective effect against ischemic brain via anti-oxidative and anti-inflammatory effects. We also showed that these effects of the dried peel powder were more powerful than those obtained with a comparable amount of NGIN alone.

Fermented Extraction of Citrus unshiu Peel Inhibits Viability and Migration of Human Pancreatic Cancers

Pancreatic cancer is one of the most dangerous cancers with high mortality rates. Despite continuous efforts, there has been limited improvement in its prognosis. In this study, we prepared fermented extract of Citrus unshiu peel (fCUP) from the by-product after juice processing and then examined the anticancer effects of fCUP on human pancreatic cancer cells. Treatment with fCUP inhibited the growth of human pancreatic cancer cells through induction of caspase-3 cleavage both in vitro and in vivo. Treatment with fCUP also blocked the migration of human pancreatic cancer cells through activation of intracellular signaling pathways such as MKK3/6 and P38. In contrast, treatment with fCUP did not inhibit growth and migration of human umbilical vein endothelial cells. In addition, we found that fCUP mainly consisted of aboriginal compounds, narirutin and hesperidin, as well as newly generated compounds, naringenin and hesperetin. In silico analysis showed that naringenin and hesperetin were the unique modules related to anticancer effect. Furthermore, fCUP exhibited the anticancer effects in in vivo xenograft models. Collectively, these results suggest that fCUP might have the potential to be developed into an effective anticancer drug for pancreatic cancers without causing adverse side-effects.

Antioxidant and anti-inflammatory activities of freeze-dried grapefruit phenolics as affected by gum arabic and bamboo fibre addition and microwave pretreatment

BACKGROUND

Recent epidemiological studies have suggested that phenolic compounds present in grapefruit play an important role in the bioactive properties of this fruit. However, the consumption of fresh grapefruit is low. Freeze-dried powdered grapefruit can be an alternative to promote this fruit consumption. To improve the quality and stability of the powdered fruit, encapsulating and anticaking agents can be added. In the present study, different grapefruit powders obtained by freeze-drying with the addition of gum arabic (1.27 g per 100 g) and bamboo fibre (0.76 g per 100 g) with and without a pre-drying microwave treatment were compared with the fresh and freeze-dried fruit with no carriers added, aiming to evaluate the effect of these preservation processes on phenolics content and on its antioxidant [1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing ability of plasma (FRAP)] and anti-inflamatory (evaluated in RAW 264.7 macrophages) capacities.

RESULTS

Freeze-drying and gum arabic and bamboo fibre addition significantly increased total phenolics, as well as the antioxidant and anti-inflammatory activities (by inhibiting nitric oxide production of lipopolysaccharide activated RAW 264.7 macrophages), of grapefruit. An additional increase in these parameters was obtained with microwave pretreatment before freeze-drying.

CONCLUSIONS

The combined addition of gum arabic and bamboo fibre to grapefruit puree and the application of a microwave pretreatment improve the functional properties of the fruit without showing cytotoxicity in vitro. © 2017 Society of Chemical Industry.

Bioactivities of Phenolics by Focusing on Suppression of Chronic Diseases: A Review

Phenolics, which are secondary metabolites of plants, exhibit remarkable bioactivities. In this contribution, we have focused on their protective effect against chronic diseases rather than their antioxidant activities, which have been widely discussed in the literature. A large body of epidemiological studies has proven the bioactivities of phenolics in both standard compounds and natural extracts: namely, anticancer, anti-inflammatory, and antibacterial activities as well as reducing diabetes, cardiovascular disease, and neurodegenerative disease. Phenolics also display anti-analgesic, anti-allergic, and anti-Alzheimer’s properties. Thus, this review provides crucial information for better understanding the bioactivities of phenolics in foods and fills a gap in the existing collective and overall knowledge in the field.

Pure total flavonoids from citrus improve non-alcoholic fatty liver disease by regulating TLR/CCL signaling pathway: A preliminary high-throughput 'omics' study

OBJECTIVE

This study investigated the possible molecular mechanisms of pure total flavonoids from citrus (PTFC) for the treatment of non-alcoholic fatty liver disease (NAFLD) via toll-like receptor/C-C chemokine ligand (TLR/CCL) signaling pathways by monitoring the changes in gene expression profile in liver tissues induced by high-fat diet.

METHODS

We performed systematical analyses on hepatic expression profiles of mRNAs in a high-fat diet (HFD)-induced steatotic animal model with or without PTFC treatment. The study was conducted by using MouseOneArray^® v2 gene chip, and analyzed by bioinformatics tools for differential gene expression. Real time-PCR, Western blot and liquid suspension array analysis were used to validate specific genes in the NAFLD liver expression profile in which PTFC plays a role in the TLR/CCR pathway.

RESULTS

We found that a total of 562 genes showed varying degrees of reversal after PTFC intervention. Pathway analysis of the differential gene expression in the HFD group and the normal diet group (ND group) revealed six signaling pathways related to inflammatory responses in the top ten results. Comparison of genes between the HFD+PTFC and the HFD groups indicated seven signaling pathways correlated with inflammatory response in the top ten results of the pathway analysis. The TLR/CCL inflammatory signaling pathways played an essential role during liver inflammation in NAFLD mice induced by high-fat diet. Real-time PCR, Western blot and liquid suspension array analysis of the differential gene expression involving the TLR/CCL signaling pathways validated the results of microarray detection.

CONCLUSION

PTFC may improve NAFLD by regulating TLR/CCL signaling pathways. Genomic studies provide additional evidence supporting the role of PTFC in the treatment of NAFLD.

Anti-inflammatory effects of phytochemicals from fruits, vegetables, and food legumes: A review

Inflammation is the first biological response of the immune system to infection, injury or irritation. Evidence suggests that the anti-inflammatory effect is mediated through the regulation of various inflammatory cytokines, such as nitric oxide, interleukins, tumor necrosis factor alpha-α, interferon gamma-γ as well as noncytokine mediator, prostaglandin E₂. Fruits, vegetables, and food legumes contain high levels of phytochemicals that show anti-inflammatory effect, but their mechanisms of actions have not been completely identified. The aim of this paper was to summarize the recent investigations and findings regarding in vitro and animal model studies on the anti-inflammatory effects of fruits, vegetables, and food legumes. Specific cytokines released for specific type of physiological event might shed some light on the specific use of each source of phytochemicals that can benefit to counter the inflammatory response. As natural modulators of proinflammatory gene expressions, phytochemical from fruits, vegetables, and food legumes could be incorporated into novel bioactive anti-inflammatory formulations of various nutraceuticals and pharmaceuticals. Finally, these phytochemicals are discussed as the natural promotion strategy for the improvement of human health status. The phenolics and triterpenoids in fruits and vegetables showed higher anti-inflammatory activity than other compounds. In food legumes, lectins and peptides had anti-inflammatory activity in most cases. However, there are lack of human study data on the anti-inflammatory activity of phytochemicals from fruits, vegetables, and food legumes.

Aqueous Extraction of Citrus unshiu Peel Induces Proangiogenic Effects Through the FAK and ERK1/2 Signaling Pathway in Human Umbilical Vein Endothelial Cells

Citrus unshiu peel has been used empirically as a traditional medicine to improve bronchial asthma and blood circulation in northeast Asian nations, including Korea, Japan, and China. In this study, we report the proangiogenic effects of the aqueous extract of Citrus unshiu peel (AECUP). In human umbilical vein endothelial cells, AECUP significantly induced cellular migration and capillary tube formation. We also demonstrated that AECUP markedly increased the phosphorylation of FAK and ERK1/2 through the integrin signaling pathway. Additionally, we identified that narirutin and hesperidin were major constituents of AECUP and both showed proangiogenic effects, but at different levels. Collectively, these results suggest that the AECUP may have potential as a therapeutic agent for improving angiogenic functions with reduced harmful side effects.

Protective effect and potential mechanisms of Wei-Chang-An pill on high-dose 5-fluorouracil-induced intestinal mucositis in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Wei-Chang-An pill (WCA pill), a traditional Chinese pharmaceutical preparation, possessed potential anti-inflammatory advantages and noteworthy gastrointestinal regulations in digestive diseases, which might represent a promising candidate for the treatment of intestinal mucositis (IM) induced by 5-fluorouracil (5-FU).

AIM OF THE STUDY

To analyze the bioactive constituents and investigate the effect of methanol extraction from WCA pill (WCA ext) on 5-FU induced IM with underlying mechanisms.

MATERIALS AND METHODS

The analysis of serum bioactive constituents after WCA ext administration in rats was carried out by UHPLC-Quadrupole-Time of Flight-Mass Spectrometry. In mice, IM was induced by 5-FU and physical manifestations were measured during the period of drug delivery. Half of mice were assessed with histology, expression of inflammatory cytokines in ileum and plasma via hematoxylin and eosin staining, immunohistochemical staining as well as cytokine enzyme-linked immunosorbent assay test, respectively. Besides, gastric emptying (GE) and gastrointestinal transit (GIT) were further tested in the other half of 5-FU induced mice.

RESULTS

Twenty-two compounds were identified or tentatively characterized. IM induced by 5-FU was improved significantly after treatment with WCA ext through reducing the body weight loss, relieving the severe diarrhea, and inhibiting the GE as well as GIT. Further assessments validated that WCA ext promoted the recovery of intestinal mucosa, evaluated the activity of enterocyte proliferation, maintained the integrity of tight junction, and ameliorated the inflammatory disturbances.

CONCLUSIONS

These results suggested that WCA ext promoted the restoration of intestinal function in 5-FU-induced IM via regulating multiple sites of actions in intestinal homeostasis. Accordingly, WCA pill might be a promising therapeutic candidate for the prevention of IM during cancer chemotherapy.

Antihyperlipidemic effects of Citrus sinensis, Citrus paradisi, and their combinations

Objective:

Hyperlipidemia, extensively contributes in the progression of coronary heart diseases and atherosclerosis, but may be managed through alterations in the nutritional pattern. Several studies show that diet rich in polyphenols and antioxidants have antiatherogenic effects. Citrus sinensis and Citrus paradisi are widely known for health benefits and have found to produce antioxidant, anti-inflammatory, and hypolipidemic effects, hence current research was planned to determine the hypolipidemic effects of C. sinensis and C. paradisi in rats receiving diet rich in cholesterol.

Materials and Methods:

All rats were divided into 11 groups each comprising 10 animals: Normal control group and hyperlipidemic control. C. sinensis treated three groups, C. paradisi treated three groups, C. sinensis and C. paradisi combination treated two groups, and group treated atorvastatin. All rats in the respective groups were treated orally with sterile water, juices, and standard drug for 8 weeks and lipid profile was estimated at the end of dosing.

Results:

Cholesterol, triglycerides (TGs), and low-density lipoprotein (LDL) were decreased at all the three doses of C. sinensis and C. paradisi but rise in high-density lipoprotein (HDL) was only significant at 8 ml/kg, and 0.3 ml/kg, respectively. Animals received the combination doses of C. sinensis and C. paradisi also showed a highly significant fall in cholesterol, LDL, and TGs, however HDL level was significantly elevated by SPJ-2 combination.

Conclusion:

Results suggest that C. sinensis and C. paradisi possess antihyperlipidemic activity due to phytochemicals and other essential nutrients, hence may serve as cardioprotective by preventing thrombosis.

Citrus unshiu peel extract alleviates cancer-induced weight loss in mice bearing CT-26 adenocarcinoma

Skeletal muscle atrophy is a critical feature of cancer-induced cachexia, caused by pro-cachectic factors secreted by host cells and tumor cells. Therefore, blockade of these factors has considered a reasonable target for pharmacological and nutritional interventions to prevent skeletal muscle loss under cancer-induced cachexia. Citrus unshiu peel (CUP) has been used for treating the common cold, dyspepsia, and bronchial discomfort and reported to have pharmacological activities against inflammation, allergy, diabetes, and viral infection. In the present study, we observed that daily oral administration of water extract of CUP (WCUP) to male BALB/c mice bearing CT-26 adenocarcinoma remarkably reduced the losses in final body weight, carcass weight, gastrocnemius muscle, epididymal adipose tissue, and hemoglobin (Hb), compared with saline treatment. The levels of serum IL-6 and muscle-specific E3 ligases elevated by tumor burden were also considerably reduced by WCUP administration. In an in vitro experiment, WCUP efficiently suppressed the production of pro-cachectic cytokines in immune cells as well as cancer cells. In addition, WCUP treatment attenuated C2C12 skeletal muscle cell atrophy caused by cancer cells. These findings collectively suggest that WCUP is beneficial as a nutritional supplement for the management of cancer patients with severe weight loss.

Flavonoid metabolites reduce tumor necrosis factor-α secretion to a greater extent than their precursor compounds in human THP-1 monocytes

Scope

Flavonoids are generally studied in vitro, in isolation, and as unmetabolized precursor structures. However, in the habitual diet, multiple flavonoids are consumed together and found present in the circulation as complex mixtures of metabolites. Using a unique study design, we investigated the potential for singular or additive anti‐inflammatory effects of flavonoid metabolites relative to their precursor structures.

Methods and results

Six flavonoids, 14 flavonoid metabolites, and 29 combinations of flavonoids and their metabolites (0.1–10 μM) were screened for their ability to reduce LPS‐induced tumor necrosis factor‐α (TNF‐α) secretion in THP‐1 monocytes. One micromolar peonidin‐3‐glucoside, cyanidin‐3‐glucoside, and the metabolites isovanillic acid (IVA), IVA‐glucuronide, vanillic acid‐glucuronide, protocatechuic acid‐3‐sulfate, and benzoic acid‐sulfate significantly reduced TNF‐α secretion when in isolation, while there was no effect on TNF‐α mRNA expression. Four combinations of metabolites that included 4‐hydroxybenzoic acid (4HBA) and/or protocatechuic acid also significantly reduced TNF‐α secretion to a greater extent than the precursors or metabolites alone. The effects on LPS‐induced IL‐1β and IL‐10 secretion and mRNA expression were also examined. 4HBA significantly reduced IL‐1β secretion but none of the flavonoids or metabolites significantly modified IL‐10 secretion.

Conclusion

This study provides novel evidence suggesting flavonoid bioactivity results from cumulative or additive effects of circulating metabolites.

Chemopreventive and therapeutic potential of "naringenin," a flavanone present in citrus fruits

Cancer is one of the major causes of deaths in developed countries and is emerging as a major public health burden in developing countries too. Changes in cancer prevalence patterns have been noticed due to rapid urbanization and changing lifestyles. One of the major concerns is an influence of dietary habits on cancer rates. Approaches to prevent cancer are many and chemoprevention or dietary cancer prevention is one of them. Therefore, nutritional practices are looked at as effective types of dietary cancer prevention strategies. Attention has been given to identifying plant-derived dietary agents, which could be developed as a promising chemotherapeutic with minimal toxic side effects. Naringenin, a phytochemical mainly present in citrus fruits and tomatoes, is a frequent component of the human diet and has gained increasing interest because of its positive health effects not only in cancer prevention but also in noncancer diseases. In the last few years, significant progress has been made in studying the biological effects of naringenin at cellular and molecular levels. This review examines the cancer chemopreventive/therapeutic effects of naringenin in an organ-specific format, evaluating its limitations, and its considerable potential for development as a cancer chemopreventive/therapeutic agent.

Auraptene in the Peels of Citrus kawachiensis (Kawachi Bankan) Ameliorates Lipopolysaccharide-Induced Inflammation in the Mouse Brain

Examination of the dried peel powder of Citrus kawachiensis, one of the citrus products of Ehime, Japan, showed that it contained naringin (NGIN; 44.02 ± 0.491 mg/g), narirutin (NRTN; 4.46 ± 0.0563 mg/g), auraptene (AUR; 4.07 ± 0.033 mg/g), and 3,5,6,7,8,3′,4′-heptamethoxyflavone (HMF; 0.27 ± 0.0039 mg/g). When this dried peel powder was orally preadministered at the dose of 1.2 or 2.4 g/kg/day for 7 days into lipopolysaccharide- (LPS-) injected mice, an animal model of systemic inflammation, it suppressed (1) LPS-induced loss of body weight and abnormal behavior in the open field, (2) LPS-induced activation of microglia and astrocytes in the hippocampus, and (3) LPS-induced expression of cyclooxygenase (COX)-2, which were coexpressed in astrocytes of these mice. When NGIN or AUR was preadministered to LPS-injected mice at an amount similar to that in the peel powder, AUR, but not NGIN, had the ability to suppress the LPS-induced inflammation in the brain of these model mice. The dried powder of flavedo tissue (the outer colored layer of the mesocarp of a citrus fruit) and juice, which contained sufficient amounts of AUR, also had anti-inflammatory effect. These results suggest that AUR was the main ingredient responsible for the anti-inflammatory property of the dried peels of C. kawachiensis.