The protective effect of the natural compound hesperetin against fulminant hepatitis in vivo and in vitro

Enhanced anti-inflammatory and anti-fibrotic effects of nanoparticles loaded with a combination of Aloe vera-Moringa oleifera extracts

Metabolic associated steatohepatitis characterized by lipid accumulation, inflammation and fibrosis, is a growing global health issue, contributing to severe liver-related mortality. With limited effective treatments available, there is an urgent need for novel therapeutic strategies. Moringa oleifera, rich in antioxidants, offers potential for combating steatohepatitis, but its cytotoxicity presents challenges. Aloe vera, renowned for its cytocompatibility and anti-inflammatory effects, shows promise in mitigating these risks. Using infrared spectrometry and mass spectrometry, we identified 1586 metabolites from both plants across 84 chemical classes. By encapsulating these phytochemicals in nanoparticles, we achieved increased solubility, cytocompatibility, and gene modulation to hepatic stellate cells affected by steatohepatitis. Chemoinformatic analysis revealed bioactive metabolites, including hesperetin analogs, known to inhibit TGF-β. Our results demonstrate that these nanoparticles not only improved gene expression modulation related to metabolic associated steatohepatitis, particularly TGF-β and COL1A1, but also outperformed free compounds, highlighting their potential as a novel therapeutic approach.

Hesperitin prevents non-alcoholic steatohepatitis by modulating mitochondrial dynamics and mitophagy via the AMPKα-Drp1/PINK1-Parkin signaling pathway

Non-alcoholic fatty liver disease (NAFLD) is becoming a global public health burden, yet effective therapeutic strategies are notably lacking. NAFLD development may be mediated by mitochondrial dysfunction, according to new research. Producing mitochondrial regulators from plant-based substances to treat mitochondrial dysfunction is an appealing approach to treating NAFLD. Hesperetin (HES) is a flavonoid that is found naturally and is a member of the flavanone family. This study aims to clarify the mechanism of HES in preventing NAFLD which is caused by a high-fat diet (HFD). Serum and liver biochemical parameters, liver histology, lipid profiles, and mitochondrial function were evaluated in HFD-induced NAFLD Sprague-Dawley (SD) rats. HES treatment significantly reduced body weight gain, liver weight, and the liver index, while also improving hepatic steatosis, lipid metabolism disorders, and mitochondrial dysfunction in rats with NAFLD. The mechanism was investigated and confirmed using western blot and real-time quantitative polymerase chain reaction (RT-qPCR). We showed that in the liver of NAFLD rats, HES decreased the expression of dynamic-related protein 1 (Drp1), phosphorylated Drp1 at serine-616 (Drp1-pS616) and induced phosphorylated Drp1 at serine-637 (Drp1-pS637), PTEN-induced kinase 1 (PINK1), and E3 Ubiquitin-Protein Ligase Parkin (Parkin) via an AMP-activated protein kinase alpha (AMPKα)-dependent mechanism. Moreover, HES increased the expression of the mitochondrial fusion proteins mitofusin-2 (Mfn2) and optic atrophy 1 (Opa1) while suppressing the expression of fission protein 1 (Fis1). In this work, we identify a unique mechanism by which HES prevents NAFLD from developing. HES may be an attractive potential therapeutic agent to cure NAFLD.

Hesperetin alleviates aflatoxin B1 induced liver toxicity in mice: Modulating lipid peroxidation and ferritin autophagy

One of the ways Aflatoxin B1 damages the liver is through ferroptosis. Ferroptosis is characterized by the build-up of lipid peroxides and reactive oxygen species (ROS) due to an excess of iron. Dietary supplements have emerged as a promising strategy for treating ferroptosis in the liver. The flavonoid component hesperetin, which is mostly present in citrus fruits, has a number of pharmacological actions, such as those against liver fibrosis, cancer, and hyperglycemia. However, hesperetin's effects and mechanisms against hepatic ferroptosis are still unknown. In this study, 24 male C57BL/6 J mice were randomly assigned to CON, AFB1 (0.45 mg/kg/day), and AFB1+ hesperetin treatment groups (40 mg/kg/day). The results showed that hesperetin improved the structural damage of the mouse liver, down-regulated inflammatory factors (Cxcl1, Cxcl2, CD80, and F4/80), and alleviated liver fibrosis induced by aflatoxin B1. Hesperetin reduced hepatic lipid peroxidation induced by iron accumulation by up-regulating the levels of antioxidant enzymes (GPX4, GSH-Px, CAT, and T-AOC). It is worth noting that hesperetin not only improved lipid peroxidation but also maintained the dynamic balance of iron ions by reducing ferritin autophagy. Mechanistically, hesperetin's ability to regulate ferritin autophagy mostly depends on the PI3K/AKT/mTOR/ULK1 pathway. In AFB1-induced HepG2 cells, the addition of PI3K inhibitor (LY294002) and AKT inhibitor (Miransertib) confirmed that hesperetin regulated the PI3K/AKT/mTOR/ULK1 pathway to inhibit ferritin autophagy and reduced the degradation of ferritin in lysosomes. In summary, our results suggest that hesperetin not only regulates the antioxidant system but also inhibits AFB1-induced ferritin hyperautophagy, thereby reducing the accumulation of iron ions to mitigate lipid peroxidation. This work provides a fresh perspective on the mechanism behind hesperetin and AFB1-induced liver damage in mice.

Hesperetin Attenuates T-2 Toxin-Induced Chondrocyte Injury by Inhibiting the p38 MAPK Signaling Pathway

BACKGROUND

Hesperetin, a flavonoid derived from citrus fruits, exhibits potent antioxidant and anti-inflammatory activities and has been implicated in cartilage protection. However, its effectiveness against T-2 toxin-induced knee cartilage damage remains unclear.

METHODS

In this study, high-throughput sequencing analysis was employed to identify the key signaling pathways involved in T-2 toxin-induced articular cartilage damage in rats. Animal models were divided into the following groups: control, low-dose T-2 toxin, high-dose T-2 toxin, T-2 toxin + hesperetin, hesperetin, and vehicle. Pathological staining and immunohistochemistry were used to assess pathological changes, as well as the expression levels of the cartilage matrix-related proteins MMP13 and collagen II, along with the activation of the p38 MAPK signaling pathway. Additionally, primary rat chondrocytes were cultured to establish an in vitro model for investigating the underlying mechanism.

RESULTS

High-throughput sequencing analysis revealed the involvement of the MAPK signaling pathway in T-2 toxin-induced articular cartilage damage in rats. Hesperetin intervention in T-2 toxin-exposed rats attenuated pathological cartilage damage. Immunohistochemistry results demonstrated a significant reduction in collagen II protein expression in the high-dose T-2 toxin group (p < 0.01), accompanied by a significant increase in MMP13 protein expression (p < 0.01). In both the articular cartilage and the epiphyseal plate, the T-2 toxin + hesperetin group exhibited significantly higher collagen II protein expression than the high-dose T-2 toxin group (p < 0.05), along with significantly lower MMP13 protein expression (p < 0.05). Hesperetin inhibited the over-activation of the p38/MEF2C signaling axis induced by T-2 toxin in primary rat chondrocytes. Compared to the T-2 toxin group, the T-2 toxin + hesperetin group showed significantly reduced phosphorylation levels of p38 and protein expression levels of MEF2C (p < 0.001 or p < 0.05). Moreover, the T-2 toxin + hesperetin group exhibited a significant decrease in MMP13 protein expression (p < 0.05) and a significant increase in collagen II protein expression (p < 0.01) compared to the T-2 toxin group.

CONCLUSIONS

T-2 toxin activates the p38 MAPK signaling pathway, causing knee cartilage damage in rats. Treatment with hesperetin inhibits the p38/MEF2C signaling axis, regulates collagen II and MMP13 protein expression, and reduces cartilage injury significantly.

Elevated PINK1/Parkin-Dependent Mitophagy and Boosted Mitochondrial Function Mediate Protection of HepG2 Cells from Excess Palmitic Acid by Hesperetin

Deregulation of mitochondrial functions in hepatocytes contributes to many liver diseases, such as nonalcoholic fatty liver disease (NAFLD). Lately, it was referred to as MAFLD (metabolism-associated fatty liver disease). Hesperetin (Hst), a bioactive flavonoid constituent of citrus fruit, has been proven to attenuate NAFLD. However, a potential connection between its preventive activities and the modulation of mitochondrial functions remains unclear. Here, our results showed that Hst alleviates palmitic acid (PA)-triggered NLRP3 inflammasome activation and cell death by inhibition of mitochondrial impairment in HepG2 cells. Hst reinstates fatty acid oxidation (FAO) rates measured by seahorse extracellular flux analyzer and intracellular acetyl-CoA levels as well as intracellular tricarboxylic acid cycle metabolites levels including NADH and FADH2 reduced by PA exposure. In addition, Hst protects HepG2 cells against PA-induced abnormal energetic profile, ATP generation reduction, overproduction of mitochondrial reactive oxygen species, and collapsed mitochondrial membrane potential. Furthermore, Hst improves the protein expression involved in PINK1/Parkin-mediated mitophagy. Our results demonstrate that it restores PA-impaired mitochondrial function and sustains cellular homeostasis due to the elevation of PINK1/Parkin-mediated mitophagy and the subsequent disposal of dysfunctional mitochondria. These results provide therapeutic potential for Hst utilization as an effective intervention against fatty liver disease.

Modulation of the crosstalk between Keap1/Nrf2/HO-1 and NF-κB signaling pathways by Tomatidine protects against inflammation/oxidative stress-driven fulminant hepatic failure in mice

Fulminant hepatic failure (FHF) is the terminal phase of acute liver injury, which is characterized by massive hepatocyte necrosis and rapid hepatic dysfunction in patients without preexisting liver disease. There are currently no therapeutic options for such a life-threatening hepatic failure except liver transplantation; therefore, the terminal phase of the underlying acute liver injury should be avoided. Tomatidine (TOM), asteroidal alkaloid, may have different biological activities, including antioxidant and anti-inflammatory effects. Herein, the lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced FHF mouse model was established to explore the protective potential of TOM and the underlying mechanisms of action. TOM pretreatment significantly inhibited hepatocyte necrosis and decreased serum aminotransferase activities in LPS/D-GalN-stimulated mice. TOM further increased the level of different antioxidant enzymes while reducing lipid peroxidation biomarkers in the liver. These beneficial effects of TOM were shown to be associated with targeting of NF-κB signaling pathways, where TOM repressed NF-κB activation and decreased LPS/D-GalN-induced TNF-α, IL-6, IL-1β, and iNOS production. Moreover, TOM prevented LPS/D-GalN-induced upregulation of Keap1 expression and downregulation of Nrf2 and HO-1 expression, leading to increased Nrf2-binding activity and HO-1 levels. Besides, TOM pretreatment repressed LPS/D-GalN-induced upregulation of proliferating cell nuclear antigen (PCNA) expression, which spared the hepatocytes from damage and subsequent repair following the LPS/D-GalN challenge. Collectively, our findings revealed that TOM has a protective effect on LPS/D-GalN-induced FHF in mice, showing powerful antioxidant and anti-inflammatory effects, primarily mediated via modulating Keap1/Nrf2/HO-1 and NF-κB/TNF-α/IL-6/IL-1β/iNOS signaling pathways.

Flavonoids contribute most to discriminating aged Guang Chenpi (Citrus reticulata 'Chachi') by spectrum-effect relationship analysis between LC-Q-Orbitrap/MS fingerprint and ameliorating spleen deficiency activity

To further explore the mechanism of "the longer storage time, the better bioactivity" of aged Guang Chenpi, the dry pericarp of Citrus reticulata 'Chachi' (CRC), a series of activity assessments were performed on spleen deficiency mice. The constituents in CRC with different storage years were analyzed by LC-Q-Orbitrap/MS. A total of 53 compounds were identified, and CRC stored for more than 5 years showed higher flavonoid content, especially that of polymethoxyflavones. Anti-spleen deficiency bioactivity analysis among various CRC with different storage years showed aged CRC (stored for more than 3 years) could significantly alleviate fatigue and depression behaviors much better, increase D-xylose and gastrin secretion, and upregulate the expression of the linking protein occludin in the colon walls. Results from 16S rDNA sequencing showed that aged CRC could downregulate the abundance of Enterococcus, Gemmata, Citrobacter, Escherichia_Shigella, and Klebsiella, which were significantly overrepresented in the model group. Bacteroides, Muribaculum, Alloprevotella, Paraprevotella, Alistipes, Eisenbergiella, and Colidextribacter were downregulated in the model group but enriched in the CRC groups. At last, the spectrum-effect relationship analysis indicated that flavonoids such as citrusin III, homoeriodictyol, hesperidin, nobiletin, and isosinensetin in aged CRC showed the highest correlation with better activity in ameliorating spleen deficiency by regulating gut microbiota. Flavonoids contribute most to discriminating aged CRC and could disclose the basis of "the longer storage time, the better bioactivity" of aged Guang Chenpi.

Trilobatin rescues fulminant hepatic failure by targeting COX2: Involvement of ROS/TLR4/NLRP3 signaling

BACKGROUND

Fulminant hepatic failure (FHF) lacks efficient therapies notwithstanding increased comprehending of the inflammatory response and oxidative stress play crucial roles in the pathogenesis of this type of hepatic damage. Trilobatin (TLB), a naturally occurring food additive, is endowed with anti-inflammation and antioxidant properties.

PURPOSE

In current study, we evaluated the effect of TLB on FHF with a mouse model with d-galactosamine/lipopolysaccharide (GalN/LPS)-induced FHF and LPS-stimulated Kupffer cells (KCs) injury.

METHODS

Mice were randomly divided into seven groups: control group, TLB 40 mg/kg + control group, GalN/LPS group, TLB 10 mg/kg + GalN/LPS group, TLB 20 mg/kg + GalN/LPS group, TLB 40 mg/kg + GalN/LPS group, bifendate 150 mg/kg + GalN/LPS group. The mice were administered intragastrically TLB (10, 20 and 40 mg/kg) for 7 days (twice a day) prior to injection of GalN (700 mg/kg)/LPS (100 µg/kg). The KCs were pretreated with TLB (2.5, 5, 10 μM) for 2 h or its analogue (10 μM) or COX2 inhibitor (10 μM), and thereafter challenged by LPS (1 μg/ml) for 24 h.

RESULTS

TLB effectively rescued GalN/LPS-induced FHF. Furthermore, TLB inhibited TLR 4/NLRP3/pyroptosis pathway, and caspase 3-dependent apoptosis pathway, along with reducing excessive cellular and mitochondrial ROS generation and enhancing mitochondrial biogenesis. Intriguingly, TLB directly bound to COX2 as reflected by transcriptomics, molecular docking technique and surface plasmon resonance assay. Furthermore, TLB failed to attenuate LPS-induced inflammation and oxidative stress in KCs in the absence of COX2.

CONCLUSION

Our findings discover a novel pharmacological effect of TLB: protecting against FHF-induced pyroptosis and apoptosis through mediating ROS/TLR4/NLRP3 signaling pathway and reducing inflammation and oxidative stress. TLB may be a promising agent with outstanding safety profile to treat FHF.

Treatment of diabetic complications: do flavonoids holds the keys?

Diabetes mellitus (DM) is an endocrinological disorder in which blood sugar levels get elevated and if unmanaged, it leads to several critical complications. Existing therapies or drugs are not able to attain absolute control of DM. Moreover, associated side/adverse effects associated with pharmacotherapy further worsen the Quality of life of patients. Present review is focused on therapeutical potential of flavonoids in management of diabetes and diabetic complications. Plenteous literature has established significant potential of flavonoids in the treatment of diabetes and diabetic complications. A number of flavonoids are found to be effective in treatment of not only diabetes but progression of diabetic complication was also found to be attenuated with the use of flavonoids. Moreover, SAR studies of some flavonoids also indicated the that efficacy of flavonoids is increased with a change in functional group of flavonoids in the treatment of diabetes and diabetic complications. A number of clinical trials are into action to investigate the therapeutic potential of flavonoids as first-line drugs or as adjuvants for treatment of diabetes and diabetic complications.. Owing to their diverse mechanism of action, efficacy and safety, flavonoids may be conscripted as potential candidate for treatment of diabetic complications.

Progress of research on the role of active ingredients of Citri Reticulatae Pericarpium in liver injury

BACKGROUND

Liver is a vital organ responsible for metabolizing and detoxifying both endogenous and exogenous substances in the body. However, it is susceptible to damage from chemical and natural toxins. The high incidence and mortality rates of liver disease and its associated complications impose a significant economic burden and survival pressure on patients and their families. Various liver diseases exist, including cholestasis, viral and non-viral hepatitis, fatty liver disease, drug-induced liver injury, alcoholic liver injury, and severe end-stage liver diseases such as cirrhosis, hepatocellular carcinoma (HCC), and cholangiocellular carcinoma (CCA). Recent research has shown that flavonoids found in Citri Reticulatae Pericarpium (CRP) have the potential to normalize blood glucose, cholesterol levels, and liver lipid levels. Additionally, these flavonoids exhibit anti-inflammatory properties, prevent oxidation and lipid peroxidation, and reduce liver toxicity, thereby preventing liver injury. Given these promising findings, it is essential to explore the potential of active components in CRP for developing new drugs to treat liver diseases.

OBJECTIVE

Recent studies have revealed that flavonoids, including hesperidin (HD), hesperetin (HT), naringenin (NIN), nobiletin (NOB), naringin (NRG), tangerine (TN), and erodcyol (ED), are the primary bioactive components in CRP. These flavonoids exhibit various therapeutic effects on liver injury, including anti-oxidative stress, anti-cytotoxicity, anti-inflammatory, anti-fibrosis, and anti-tumor mechanisms. In this review, we have summarized the research progress on the hepatoprotective effects of HD, HT, NIN, NOB, NRG, TN, ED and limonene (LIM), highlighting their underlying molecular mechanisms. Despite their promising effects, the current clinical application of these active ingredients in CRP has some limitations. Therefore, further studies are needed to explore the full potential of these flavonoids and develop new therapeutic strategies for liver diseases.

METHODS

For this review, we conducted a systematic search of three databases (ScienceNet, PubMed, and Science Direct) up to July 2022, using the search terms "CRP active ingredient," "liver injury," and "flavonoids." The search data followed the PRISMA standard.

RESULTS

Our findings indicate that flavonoids found in CRP can effectively reduce drug-induced liver injury, alcoholic liver injury, and non-alcoholic liver injury. These therapeutic effects are mainly attributed to the ability of flavonoids to improve liver resistance to oxidative stress and inflammation while normalizing cholesterol and liver lipid levels by exhibiting anti-free radical and anti-lipid peroxidation properties.

CONCLUSION

Our review provides new insights into the potential of active components in CRP for preventing and treating liver injury by regulating various molecular targets within different cell signaling pathways. This information can aid in the development of novel therapeutic strategies for liver disease.

Hesperetin attenuates sepsis-induced intestinal barrier injury by regulating neutrophil extracellular trap formation via the ROS/autophagy signaling pathway

Background: Hesperetin (HES), one of the major flavonoids that has various biological activities, such as anti-inflammatory and antioxidant activities, may preserve the intestinal barrier during sepsis. However, the detailed mechanism remains unclear. Our previous studies confirmed that neutrophil extracellular traps (NETs) may jeopardize the intestinal barrier via a reactive oxygen species (ROS)-dependent pathway during sepsis. Therefore, we hypothesized that HES may inhibit NET formation and protect the intestinal barrier function during sepsis. Methods: Mice were pretreated with HES (50 mg kg-1) intraperitoneally for one week, and sepsis models were then induced using lipopolysaccharides (LPS) (10 mg kg-1). The mice were randomly divided into three groups: (1) sham group; (2) LPS group; and (3) HES + LPS group. Twenty-four hours after LPS injection, the serum and terminal ileum specimens were collected for subsequent studies. To detect ROS production and NET formation in vitro, human neutrophils were collected and incubated with phorbol-12-myristate-13-acetate (PMA) and various concentrations of HES. The level of autophagy was measured by an immunofluorescence assay and western blot analysis. TUNEL staining was utilized to analyze cell apoptosis. Results: The outcomes demonstrated that HES decreased inflammatory cytokine and myeloperoxidase (MPO) levels in serum and attenuated distant organ dysfunction in LPS-induced septic mice. Meanwhile, HES treatment reversed intestinal histopathological damage in septic mice, improving intestinal permeability and enhancing tight junction expression. Moreover, we found that neutrophil infiltration and NET formation in the intestine were suppressed during sepsis after HES pretreatment. In vitro, HES treatment reduced PMA-induced ROS production and NET formation, which were reversed by hydrogen peroxide (H2O2) administration. Notably, HES also inhibited NET formation by reducing the microtubule-associated protein light chain 3 (LC3)-II/LC3-I ratio (an indicator of autophagy) in PMA-induced neutrophils, which was reversed by rapamycin. Moreover, when autophagy was suppressed by chloroquine or induced by rapamycin, apoptosis in cells will be switched with autophagy. Conclusion: Taken together, these findings suggest that HES may inhibit NET formation in a ROS/autophagy-dependent manner and switch neutrophil death from NETosis to apoptosis, which reduced NETs-related intestinal barrier damage, providing a novel protective role in intestinal barrier dysfunction during sepsis.

Expression of VEGF and CD-31 in traumatic ulcer of diabetic Wistar rats after application of Citrus limon peel essential oil

Objective

Diabetes mellitus (DM) is a metabolic disease that delays the healing process, including the interruption of the processes of angiogenesis and vasculogenesis. The etiology of most angiogenic-related diseases, such as diabetes complications, includes the presence of hypoxia caused by declined vascular endothelium growth factor (VEGF) and CD-31. d-limonene, one of the main constituents of Citrus limon, is considered to have angiogenic, antioxidant, hypoglycemic, and anti-inflammatory activities. However, the exact mechanism of this process remains unclear. This study aimed to determine the potential of C. limon as a medication for diabetic ulceration.

Methods

A total of 30 Wistar rats (Rattus novergicus) induced with DM and traumatic ulcers on the lower lip mucosa were divided into six groups-three each for control and treatment groups. Control groups were treated with CMC 5% gel, and treatment groups were administered with C. limon peel essential oil gel. The expression of VEGF and CD-31 was observed on days 5, 7, and 9. Immunohistochemical examinations were performed with the monoclonal antibodies anti-VEGF and anti-CD-31. ANOVA was conducted to analyze the differences between the groups (p < 0.05).

Result

An increase in VEGF and CD-31 expression in the treatment group was observed compared with that of the control group (p < 0.05).

Conclusion

Citrus limon peel essential oil gel increased VEGF and CD-31 expression during the healing process of traumatic ulcers in diabetes-afflicted Wistar rats.

Molecular mechanism of anti-inflammatory effects of the proteasome inhibitor MG-132 on Con A-induced acute liver injury in mice

MG-132, an aldehyde-based peptide proteasome inhibitor (PI) that binds to the proteasome and reversibly inhibits proteasome activity, has been widely used in experimental research. However, it is not clear whether MG-132 has anti-inflammatory effects on liver injury. The molecular mechanism of the anti-inflammatory effect of the PI MG-132 on Con A-induced acute liver injury (ALI) mice was investigated by ELISA, HE, q RT-PCR, and IHC. The results showed that the serum activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and TNF-α and IL-6 contents of mice in the high and medium dose groups were reduced compared with those in the ALI group. The superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels in liver tissues were significantly increased, and the malondialdehyde (MDA) content was decreased. The pathological sections of mice in the ALI group showed typical ALI manifestations such as significant central venous stasis of liver tissues, cell swelling, and inflammatory cell infiltration. The pathological damage of liver tissues was relieved significantly in the three dose groups, especially in the high-dose group. The transcriptional level of TLR4/NF-κB pathway key factors mRNA was significantly reduced, and the expression of TLR4 and NF-κB P65 protein in liver tissues was significantly and positively correlated with the contents of TNF-α and IL-1β (p < 0.01). Our findings suggest that MG-132 can alleviate the inflammatory response to Con A-induced ALI and exert a hepatoprotective effect, and its anti-inflammatory effect is related to the inhibition of TLR4/NF-κB signaling pathway activation.

Anti-hyperuricemia effect of hesperetin is mediated by inhibiting the activity of xanthine oxidase and promoting excretion of uric acid

Hesperetin is a natural flavonoid with many biological activities. In view of hyperuricemia treatment, the effects of hesperetin in vivo and in vitro, and the underlying mechanisms, were explored. Hyperuricemia models induced by yeast extract (YE) or potassium oxonate (PO) in mice were created, as were models based on hypoxanthine and xanthine oxidase (XOD) in L-O2 cells and sodium urate in HEK293T cells. Serum level of uric acid (UA), creatinine (CRE), and urea nitrogen (BUN) were reduced significantly after hesperetin treatment in vivo. Hesperetin provided hepatoprotective effects and inhibited xanthine oxidase activity markedly, altered the level of malondialdehyde (MDA), glutathione peroxidase (GSH-PX) and catalase (CAT), downregulated the XOD protein expression, toll-like receptor (TLR)4, nucleotide binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, interleukin-18 (IL-18), upregulated forkhead box O3a (FOXO3a), manganese superoxide dismutase (MnSOD) in a uric acid-synthesis model in mice. Protein expression of organic anion transporter 1 (OAT1), OAT3, organic cationic transporter 1 (OCT1), and OCT2 was upregulated by hesperetin intervention in a uric acid excretion model in mice. Our results proposal that hesperetin exerts a uric acid-lowering effect through inhibiting xanthine oxidase activity and protein expression, intervening in the TLR4-NLRP3 inflammasome signaling pathway, and up-regulating expression of FOXO3a, MnSOD, OAT1, OAT3, OCT1, and OCT2 proteins. Thus, hesperetin could be a promising therapeutic agent against hyperuricemia.

Hesperetin, a Promising Dietary Supplement for Preventing the Development of Calcific Aortic Valve Disease

BACKGROUND

No effective therapeutic agents for calcific aortic valve disease (CAVD) are available currently. Dietary supplementation has been proposed as a novel treatment modality for various diseases. As a flavanone, hesperetin is widely abundant in citrus fruits and has been proven to exert protective effects in multiple diseases. However, the role of hesperetin in CAVD remains unclear.

METHODS

Human aortic valve interstitial cells (VICs) were isolated from aortic valve leaflets. A mouse model of aortic valve stenosis was constructed by direct wire injury (DWI). Immunoblotting, immunofluorescence staining, and flow cytometry were used to investigate the roles of sirtuin 7 (Sirt7) and nuclear factor erythroid 2-related factor 2 (Nrf2) in hesperetin-mediated protective effects in VICs.

RESULTS

Hesperetin supplementation protected the mice from wire-injury-induced aortic valve stenosis; in vitro, hesperetin inhibited the lipopolysaccharide (LPS)-induced activation of NF-κB inflammatory cytokine secretion and osteogenic factors expression, reduced ROS production and apoptosis, and abrogated LPS-mediated injury to the mitochondrial membrane potential and the decline in the antioxidant levels in VICs. These benefits of hesperetin may have been obtained by activating Nrf2-ARE signaling, which corrected the dysfunctional mitochondria. Furthermore, we found that hesperetin could directly bind to Sirt7 and that the silencing of Sirt7 decreased the effects of hesperetin in VICs and potently abolished the ability of hesperetin to increase Nrf2 transcriptional activation.

CONCLUSIONS

Our work demonstrates that hesperetin plays protective roles in the aortic valve through the Sirt7-Nrf2-ARE axis; thus, hesperetin might be a potential dietary supplement that could prevent the development of CAVD.

Hesperidin Inhibits the p53-MDMXInteraction-Induced Apoptosis of Non-Small-Cell Lung Cancer and Enhances the Antitumor Effect of Carboplatin

Objective

This study aimed to observe the effect of hesperidin on the apoptosis, proliferation, and invasion of non-small-cell lung cancer, as well as to explore the possible mechanism. The inhibitory effect of hesperidin combined with carboplatin on non-small-cell lung cancer was also investigated.

Methods

A549 and NCI-H460 cells were treated with different concentrations of hesperidin (10, 50, and 100 μM). The effect of siRNA knockdown on MDMX on the antitumor effect of hesperidin was observed. CCK-8 was used to detect cell activity. The apoptosis rate was determined by TUNEL. The transwell assay detects the ability of cell migration and invasion. The expression levels of the apoptosis-related proteins p53, MDM2, MDMX, p21, PUMA, Bcl-2, and Bax were detected by qRT-PCR. Cell-proliferation and transwell assays were used to detect the effects of the combined use of hesperidin and carboplatin on lung cancer cells.

Results

Hesperidin significantly inhibited the activity and invasion of A549 and NCI-H460 cells in a dose-dependent manner. Hesperidin also induced the apoptosis of A549 and NCI-H460 cells. Hesperidin further inhibited the interaction between p53 and MDMX, increased the expression of p53, and played an anticancer role. The combination of hesperidin and carboplatin showed the most obvious antitumor effect.

Conclusion

Hesperidin can inhibit lung cancer by inhibiting the interaction between p53 and MDMX. Moreover, the combination of hesperidin and carboplatin can inhibit the migration and invasion of lung cancer cell lines through p53 upregulation, thereby increasing the antitumor effect of carboplatin.

Traditional Chinese medicine promotes bone regeneration in bone tissue engineering

Bone tissue engineering (BTE) is a promising method for the repair of difficult-to-heal bone tissue damage by providing three-dimensional structures for cell attachment, proliferation, and differentiation. Traditional Chinese medicine (TCM) has been introduced as an effective global medical program by the World Health Organization, comprising intricate components, and promoting bone regeneration by regulating multiple mechanisms and targets. This study outlines the potential therapeutic capabilities of TCM combined with BTE in bone regeneration. The effective active components promoting bone regeneration can be generally divided into flavonoids, alkaloids, glycosides, terpenoids, and polyphenols, among others. The chemical structures of the monomers, their sources, efficacy, and mechanisms are described. We summarize the use of compounds and medicinal parts of TCM to stimulate bone regeneration. Finally, the limitations and prospects of applying TCM in BTE are introduced, providing a direction for further development of novel and potential TCM.

Hesperetin protects against diesel exhaust particles-induced cardiovascular oxidative stress and inflammation in Wistar rats

Air particulate matter exposure has been linked to cardiovascular and atherosclerosis as a result of increase oxidative stress and inflammatory response. This study aims to determine the effect of the use of hesperetin (HESP) as a therapeutic agent to mitigate the cardiovascular oxidative and pro-inflammatory effects of diesel exhaust particles in Wistar rats. DEP was collected from an Iveco cargo engine truck, and n-hexane fraction (hDEP) was obtained. Forty Wistar strains of male albino rats (6 weeks) were divided into 8 groups: control group received DMSO and CMC-Na; other groups received either n-hexane extract of DEP (0.064 or 0.640 mg/kg hDEP) or Standard Reference Material 2975 (0.064 mg/kg hSRM) in the presence or absence of 200 mg/kg HESP. Extracts were administered orally. Serum lipids, lipid peroxidation (LPO), conjugated dienes (CDs), and GSH levels were determined. Also, inflammatory cytokines, PCSK-9, LDL-receptor, and antioxidant genes expression were assessed by RT-PCR in both the heart and aorta. The molecular interaction of targeted proteins with HESP was assessed by the in silico approach. Extracts of DEP caused a significant (p < 0.001) increase in serum lipids but significantly decreased HDL-CHOL. It also increased CDs and MDA levels but decreased GSH levels. In addition, the particulate extracts caused a significant (p < 0.001) increase in pro-inflammatory genes expression in the heart and aorta but significantly decreased IL-10 and LDL-R gene expressions. Pre-treatment with hesperetin significantly reversed all these effects. This study shows that hesperetin has the ability to protect against DEP-induced oxidative stress and inflammation in the cardiovascular system.

Regulation of endoplasmic reticulum stress by hesperetin: Focus on antitumor and cytoprotective effects

BACKGROUND

Cancer is still an all-times issue due to a large and even increasing number of deaths. Impaired genes regulating cell proliferation and apoptosis are targets for the development of novel cancer treatments.

HYPOTHESIS

Increased transcription of NADPH oxidase activator (NOXA), Bcl2-like11 (BIM), BH3-only proteins and p53 unregulated apoptosis modulator (PUMA) is caused by the imbalance between pro- and anti-apoptotic Bcl-2 proteins due to endoplasmic reticulum (ER) stress. The membranous network of ER is present in all eukaryotic cells. ER stress facilitates the interaction between Bax and PUMA, triggering the release of cytochrome C. As a main intracellular organelle, ER is responsible for translocation as well as post-translation modification and protein folding.

RESULTS

Hesperetin is a cytoprotective flavonone, which acts against ER stress and protects from cell damage induced by reactive oxygen species (ROS) and reactive nitrogen species (RNS). Hesperetin inhibits lipid peroxidation induced by Fe²⁺ and l-ascorbic acid in rat brain homogenates.

CONCLUSION

This review deals with the anticancer effects of hesperetin regarding the regulation of ER stress as a principal mechanism in the pathogenesis of tumors.

Scopoletin and umbelliferone protect hepatocytes against palmitate- and bile acid-induced cell death by reducing endoplasmic reticulum stress and oxidative stress

BACKGROUND

The number of patients with non-alcoholic fatty liver disease (NAFLD) is rapidly increasing due to the growing epidemic of obesity. Non-alcoholic steatohepatitis (NASH), the inflammatory stage of NAFLD, is characterized by lipid accumulation in hepatocytes, chronic inflammation and hepatocyte cell death. Scopoletin and umbelliferone are coumarin-like molecules and have antioxidant, anti-cancer and anti-inflammatory effects. Cytoprotective effects of these compounds have not been described in hepatocytes and the mechanisms of the beneficial effects of scopoletin and umbelliferone are unknown.

AIM

To investigate whether scopoletin and/or umbelliferone protect hepatocytes against palmitate-induced cell death. For comparison, we also tested the cytoprotective effect of scopoletin and umbelliferone against bile acid-induced cell death.

METHODS

Primary rat hepatocytes were exposed to palmitate (1 mmol/L) or the hydrophobic bile acid glycochenodeoxycholic acid (GCDCA; 50 μmol/L). Apoptosis was assessed by caspase-3 activity assay, necrosis by Sytox green assay, mRNA levels by qPCR, protein levels by Western blot and production of reactive oxygen species (ROS) by fluorescence assay.

RESULTS

Both scopoletin and umbelliferone protected against palmitate and GCDCA-induced cell death. Both palmitate and GCDCA induced the expression of ER stress markers. Scopoletin and umbelliferone decreased palmitate- and GCDCA-induced expression of ER stress markers, phosphorylation of the cell death signaling intermediate JNK as well as ROS production.

CONCLUSION

Scopoletin and umbelliferone protect against palmitate and bile acid-induced cell death of hepatocytes by inhibition of ER stress and ROS generation and decreasing phosphorylation of JNK. Scopoletin and umbelliferone may hold promise as a therapeutic modality for the treatment of NAFLD.

CQMUH-011 mitigates autoimmune hepatitis via inhibiting the function of T lymphocytes

CQMUH-011 is a modified adamantane sulfonamide compound, that inhibits macrophage proliferation and possesses anti-inflammatory properties. Here, fresh mouse splenocytes were obtained and stimulated with concanavalin A (ConA, 5 μg/ml) in vitro; and experimental autoimmune hepatitis (AIH) was induced by ConA (20 mg/kg, iv) in vivo, to clarify the protective effects of CQMUH-011 against AIH and its possible mechanisms. Our results demonstrated that CQMUH-011 pretreatment can dose-dependently inhibit the proliferation of splenocytes in vitro. In vivo, CQMUH-011 administration reduced the hepatic histopathological score and the infiltration of lymphocytes in the liver parenchyma; additionally, it downregulated the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and pro-inflammatory cytokines interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and interleukin (IL)-6 in serum, as well as those of methane dicarboxylic aldehyde and myeloperoxidase in the liver tissues. It also down-regulated the expression of p-NF-κB and related proteins in the liver tissues. Furthermore, CQMUH-011 could maintain the balance of CD3+ CD4+ /CD3+ CD8+ and decrease the percentages of CD8+ CD69+ and CD4+ CD25+/- CD69+ T-cells in the splenocytes of ConA-challenged mice. Moreover, we found thatCD4+ CD25+/- CD69+ T-cells were significantly correlated with ALT levels, especially CD4+ CD25- CD69+ T-cells. In conclusion, CQMUH-011 exerts potential protective effects against ConA-induced hepatitis, which may be partially attributed to its inhibition of T cells, especially the suppression of the proliferation of CD4+ CD25- CD69+ and CD8+ CD69+ subsets in the spleen. CQMUH-011 also reduced the early apoptosis of lymphocytes in the thymus.

Cichorium pumilum Jacq Extract Inhibits LPS-Induced Inflammation via MAPK Signaling Pathway and Protects Rats From Hepatic Fibrosis Caused by Abnormalities in the Gut-Liver Axis

The development of liver fibrosis is closely related to the gut microbiota, and the "gut-liver axis" is the most important connection between the two. ethyl acetate extract of Cichorium pumilum Jacq (CGEA) is an herbal extract consisting mainly of sesquiterpenoids. The anti-inflammatory and hepatoprotective effects of CGEA have been reported, but the anti-fibrotic effects of CGEA via intestinal microbes and the "gut-liver axis" cycle have rarely been reported. In this study, we observed that CGEA not only directly attenuated inflammatory factor levels in inflamed mice, but also attenuated liver inflammation as well as liver fibrosis degeneration in rats with liver fibrosis caused by colitis. We observed in vitro that CGEA significantly promoted the growth of Bifidobacterium adolescentis. Similarly, fecal 16S rDNA sequencing of liver fibrosis rats showed that CGEA intervention significantly altered the composition of the intestinal microbiota of liver fibrosis rats. CGEA increased the abundance of intestinal microbiota, specifically, CGEA increased the ratio of Firmicutes to Bacteroidetes, CGEA could significantly increase the levels of Ruminococcus. In addition, CGEA intervention significantly protected intestinal mucosal tissues and improved intestinal barrier function in rats. Lactucin is the main sesquiterpenoid in CGEA, and HPLC results showed its content in CGEA was up to 6%. Lactucin has been reported to have significant anti-inflammatory activity, and in this study, we found that Lactucin decreased p38 kinases (p38), phosphorylation of the extracellular signal-regulated kinase (ERK) and protein kinase B (AKT) protein phosphorylation in lipopolysaccharide (LPS)-activated RAW264.7 cells, thereby reducing mRNA expression and protein expression of pro-inflammatory factors inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and inhibiting the release of inflammatory factors interleukin (IL)-6 and nitric oxide (NO), exerting anti-inflammatory effects. In summary, the prevention of liver fibrosis caused by intestinal inflammation by CGEA may be achieved by regulating the intestinal microbiota and restoring the intestinal barrier thereby improving the "gut-liver axis" circulation, reducing liver inflammation, and ultimately alleviating liver fibrosis. Notably, the direct anti-inflammatory effect of CGEA may be due to its content of Lactucin, which can exert anti-inflammatory effects by inhibiting the phosphorylation of Mitogen-activated protein kinase (MAPK) and Akt signaling pathways.

Hesperetin attenuates silica-induced lung injury by reducing oxidative damage and inflammatory response

Oxidative stress and the inflammatory response are two important mechanisms of silica-induced lung injury. Hesperetin (HSP) is a natural flavonoid compound that is found in citrus fruits and has been indicated to exhibit strong antioxidant and anti-inflammatory properties. The current study evaluated the protective effect of HSP on lung injury in rats exposed to silica. The results indicated that the degree of alveolitis and pulmonary fibrosis in the HSP-treated group was significantly decreased compared with the silica model group. The content of hydroxyproline (HYP) was also revealed to decrease overall in the HSP treated group compared with the silica model group, indicating that the degree of pulmonary fibrosis was decreased compared with the silica model group. The present study also demonstrated that HSP reduced oxidation levels of malondialdehyde (MDA) and increased the activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-PX). Total antioxidant capacity (T-AOC) was also increased following HSP treatment, indicating that HSP can alleviate oxidative stress in the lung tissue of silica-exposed rats. In addition, HSP was revealed to inhibit the synthesis and secretion of fibrogenic factor TGF-β1, reduce the production of pro-inflammatory cytokines IL-1β, IL-4, TNF-α and increase the levels of anti-inflammatory factors IFN-γ and IL-10. The current study demonstrated that HSP can effectively attenuate silica-induced lung injury by reducing oxidative damage and the inflammatory response.

Role of Oxidative Stress in the Pathogenesis of Non-Alcoholic Fatty Liver Disease: Implications for Prevention and Therapy

Oxidative stress (OxS) is considered a major factor in the pathophysiology of inflammatory chronic liver diseases, including non-alcoholic liver disease (NAFLD). Chronic impairment of lipid metabolism is closely related to alterations of the oxidant/antioxidant balance, which affect metabolism-related organelles, leading to cellular lipotoxicity, lipid peroxidation, chronic endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Increased OxS also triggers hepatocytes stress pathways, leading to inflammation and fibrogenesis, contributing to the progression of non-alcoholic steatohepatitis (NASH). The antioxidant response, regulated by the Nrf2/ARE pathway, is a key component in this process and counteracts oxidative stress-induced damage, contributing to the restoration of normal lipid metabolism. Therefore, modulation of the antioxidant response emerges as an interesting target to prevent NAFLD development and progression. This review highlights the link between disturbed lipid metabolism and oxidative stress in the context of NAFLD. In addition, emerging potential therapies based on antioxidant effects and their likely molecular targets are discussed.

Hesperetin's health potential: moving from preclinical to clinical evidence and bioavailability issues, to upcoming strategies to overcome current limitations

Flavonoids are common in the plant kingdom and many of them have shown a wide spectrum of bioactive properties. Hesperetin (Hst), the aglycone form of hesperidin, is a great example, and is the most abundant flavonoid found in Citrus plants. This review aims to provide an overview on the in vitro, in vivo and clinical studies reporting the Hst pharmacological effects and to discuss the bioavailability-related issues. Preclinical studies have shown promising effects on cancer, cardiovascular diseases, carbohydrate dysregulation, bone health, and other pathologies. Clinical studies have supported the Hst promissory effects as cardioprotective and neuroprotective agent. However, further well-designed clinical trials are needed to address the other Hst effects observed in preclinical trials, as well as to a more in-depth understanding of its safety profile.

Hesperetin, a SIRT1 activator, inhibits hepatic inflammation via AMPK/CREB pathway

Silent mating type information regulation 2 homolog 1 (SIRT1) is an important inflammatory regulator, which epigenetically reprograms inflammation by altering the acetylation of NF-κB. Hesperetin, as a common flavonoid, has been proven to have a significant effect on acute inflammatory diseases. However, the detailed molecular mechanism by which hesperetin alleviates inflammatory response and accompanied tissue injury is poorly understood. Our results show that SIRT1 is required for the inhibitory effect of hesperetin on inflammation. Hesperetin suppresses the acetylation of RelA/p65 to reduce NF-κB activity by inducing SIRT1 expression. Mechanistically, hesperetin increases SIRT1 expression through AMPK/CREB pathway. Additionally, the protective effect of hesperetin against LPS/D-GalN-induced hepatitis in mice is also dependent on SIRT1. Our study suggests that hesperetin is an SIRT1 activator and could be potential candidates for the treatments of inflammatory conditions.

Recognition of Natural Products as Potential Inhibitors of COVID-19 Main Protease (Mpro): In-Silico Evidences

SARS-CoV-2 (2019-nCoV) emerged in 2019 and proliferated rapidly across the globe. Scientists are attempting to investigate antivirals specific to COVID-19 treatment. The 2019-nCoV and SARS-CoV utilize the same receptor of the host which is COVID-19 of the main protease (Mpro).COVID-19 caused by SARS-CoV-2 is burdensome to overcome by presently acquired antiviral candidates. So the objective and purpose of this work was to investigate the plants with reported potential antiviral activity. With the aid of in silico techniques such as molecular docking and druggability studies, we have proposed several natural active compounds including glycyrrhizin, bicylogermecrene, tryptanthrine, β-sitosterol, indirubin, indican, indigo, hesperetin, crysophanic acid, rhein, berberine and β-caryophyllene which can be encountered as potential herbal candidate exhibiting anti-viral activity against SARS-CoV-2. Promising docking outcomes have been executed which evidenced the worthy of these selected herbal remedies for future drug development to combat coronavirus disease.

Hesperetin protects against palmitate-induced cellular toxicity via induction of GRP78 in hepatocytes

Lipotoxicity plays a critical role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Hesperetin, a flavonoid derivative, has anti-oxidant, anti-inflammatory and cytoprotective properties. In the present study, we aim to examine whether hesperetin protects against palmitate-induced lipotoxic cell death and to investigate the underlying mechanisms in hepatocytes. Primary rat hepatocytes and HepG2 cells were pretreated with hesperetin for 30 min and then exposed to palmitate (1.0 mmol/L in primary rat hepatocytes; 0.5 mmol/L in HepG2 cells) in the presence or absence of hesperetin. Necrotic cell death was measured via Sytox green nuclei staining and quantified by LDH release assay. Apoptotic cell death was determined by caspase 3/7 activity and the protein level of cleaved-PARP. The unfolded protein response (UPR) was assessed by measuring the expression of GRP78, sXBP1, ATF4 and CHOP. Results show that hesperetin (50 μmol/L and 100 μmol/L) protected against palmitate-induced cell death and inhibited palmitate-induced endoplasmic reticulum (ER) stress in both primary rat hepatocytes and HepG2 cells. Hesperetin (100 μmol/L) significantly activated sXBP1/GRP78 signaling, whereas a high concentration of hesperetin (200 μmol/L) activated p-eIF2α and caused hepatic cell death. Importantly, GRP78 knockdown via siRNA abolished the protective effects of hesperetin in HepG2 cells. In conclusion, hesperetin protected against palmitate-induced hepatic cell death via activation of the sXBP1/GRP78 signaling pathway, thus inhibiting palmitate-induced ER stress. Moreover, high concentrations of hesperetin induce ER stress and subsequently cause cell death in hepatocytes.

Influence of Hesperidin on Systemic Immunity of Rats Following an Intensive Training and Exhausting Exercise

Intensive training and exhausting exercise can disrupt innate and acquired immunity. The flavanone hesperidin has shown immunomodulatory properties in physiological and some pathological conditions, and positive effects on exercise-induced oxidative stress. Nevertheless, it remains uncertain whether it also prevents exhausting exercise-induced immune alterations. The aim of this study was to establish the effect of oral hesperidin supplementation on the systemic immune system in rats following an intensive training and exhausting exercise. For this purpose, female Wistar rats were randomized into an intensive training group or a sedentary group. Intensive training was induced by running in a treadmill 5 days per week (including two exhausting tests) for five weeks. Throughout the training period, 200 mg/kg of hesperidin or vehicle was administered by oral gavage three times per week. At the end, blood, thymus, spleen and macrophages were collected before, immediately after and 24 h after an additional final exhaustion test. Hesperidin supplementation enhanced natural killer cell cytotoxicity and the proportion of phagocytic monocytes, attenuated the secretion of cytokines by stimulated macrophages, prevented the leukocytosis induced by exhaustion and increased the proportion of T helper cells in the thymus, blood and spleen. These results suggest that hesperidin can prevent exhausting exercise-induced immune alterations.

Hesperetin attenuated acetaminophen-induced hepatotoxicity by inhibiting hepatocyte necrosis and apoptosis, oxidative stress and inflammatory response via upregulation of heme oxygenase-1 expression

Acetaminophen (APAP) is a common antipyretic and analgesic drug, but its overdose can induce acute liver failure with lack of effective therapies. Hesperetin, a dihydrogen flavonoid compound, has been revealed to exert multiple pharmacological activities. Here, we explored the protective effects and mechanism of hesperetin on APAP-induced hepatotoxicity. The results showed that pretreatment with hesperetin dose-dependently attenuated APAP-induced acute liver injury in mice, as measured by alleviated serum enzymes activities, hepatic pathological damage and apoptosis. Moreover, hesperetin mitigated APAP-induced oxidative stress and inflammatory response in mice by inhibiting oxidative molecules but increasing antioxidative molecules production, reducing inflammatory cells infiltration and proinflammatory cytokines production, blocking Toll-like receptor (TLR)-4 signal activation. In vitro experiment indicated that hesperetin dose-dependently inhibited APAP-primed cytotoxicity, apoptosis, and reactive oxygen species (ROS) in murine AML12 hepatocytes. Notably, hesperetin up-regulated expression of heme oxygenase-1 (HO-1) mRNA and protein in the liver of mice and AML12 cells exposed to APAP. Furthermore, knockdown of HO-1 by adenovirus-mediated HO-1 siRNA reverted these beneficial effects of hesperetin on APAP-induced hepatocytotoxicity as well as ROS and inflammatory response in vivo and in vitro. These findings demonstrated that hesperetin exerted a protective prophylaxis on APAP-induced acute liver injury by inhibiting hepatocyte necrosis and apoptosis, oxidative stress and inflammatory response via up-regulating HO-1 expression.

Hesperetin ameliorates DSS-induced colitis by maintaining the epithelial barrier via blocking RIPK3/MLKL necroptosis signaling

Hesperetin, a flavonoid from citrus fruits, possess various pharmacological properties, including anti-inflammatory, anti-oxidative, anti-tumor potentials. However, the role and its mechanism in ulcerative colitis (UC) remains unclear. This study aimed to investigate the protective effects and mechanisms of hesperetin on dextran sodium sulfate (DSS) -induced colitis. Our results showed that hesperetin significantly relieved the symptoms of DSS -induced colitis and increased the expressions of zonula occludens-1 (ZO-1), occludin and mucin2 (MUC-2) as well as the decrease of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-18, HMGB1 and IL-6. Of note, results from immunohistochemistry (IHC) and western blotting indicated that hesperetin inhibited the expressions of receptor-interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like (MLKL), the two key proteins of necroptosis pathway, and inactivated RIPK3/MLKL necroptosis signalling. Meanwhile, in the cell-coculture system between Caco-2 and RAW264.7 cells, hesperetin treatment significantly ameliorated the decrease of trans epithelial electric resistance (TEER) value while HS-173 (necroptosis inducer) could obviously influence the effect of hesperetin. In addition, hesperetin attenuated the LPS-induced increasing in 4-kDa fluorescein isothiocyanate-dextran (FD4) permeability while HS-173 could weaken the protective effect of hesperetin. Meanwhile, HS-173 reduced the changes in the expressions of phosphorylated RIPK3, phosphorylated MLKL, ZO-1, occludin and MUC-2 as well as TNF-α, IL-1β. These findings demonstrated hesperetin ameliorated DSS-induced colitis by maintaining the epithelial barrier via blocking the intestinal epithelial necroptosis.

Effect of hesperetin on systemic inflammation and hepatic injury after blunt chest trauma in rats

We investigated the protective effect of hesperetin on hepatic damage after blunt chest trauma in rats using histological and biochemical methods. We used 18 adult male rats in three groups of six: control, chest trauma and chest trauma + hesperetin. Chest trauma was caused by dropping a metal cylinder onto the right hemithorax. Hesperetin, 100 mg/kg, was administered orally for 7 days. At the end of the seventh day, liver tissue samples were obtained. Serum tumor necrosis factor-alpha (TNF-α), interleukin 1-beta (IL-1β), alanine aminotransferase (AST), aspartate transferase (ALT) and lactate dehydrogenase (LDH) enzyme activities were measured in blood samples taken from the heart. The general structure of liver tissue was investigated using hematoxylin and eosin staining. Nuclear factor kappa beta (Nf-κβ) expression in liver tissue was determined by the indirect immunohistochemical method. Apoptosis was determined using the terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) method. Decreased TNF-α, AST and ALT enzyme activity, fewer histopathological changes and lower Nf-kB expression were observed in the hesperetin treated group compared to the chest trauma group. We also found reduced hepatic apoptosis in the chest trauma + hesperetin group compared to the chest trauma group. Hesperetine inhibits liver damage by reducing proinflammatory cytokines and by suppressing Nf-κβ activity in a blunt chest trauma model in rats.

Nicotine attenuates concanavalin A-induced liver injury in mice by regulating the α7-nicotinic acetylcholine receptor in Kupffer cells

Nicotine, a potent parasympathomimetic alkaloid, manifests anti-inflammatory properties by activating nicotinic acetylcholine receptors (nAChRs). In this study, we evaluated the effects of nicotine on concanavalin A (ConA)-induced autoimmune hepatitis. Nicotine (0.5 and 1 mg/kg) was intraperitoneally administered to BALB/c mice and mice were intravenously injected with ConA (15 mg/kg) to induce hepatitis. The results showed that nicotine treatment ameliorated pathological lesions in livers and significantly suppressed the expression of pro-inflammatory cytokines in the livers. Such effects were mediated by inhibiting the nuclear factor-kappa B (NF-κB) signaling in livers. Interestingly, nicotine inhibited the ConA-induced inflammatory response in primary cultured Kupffer cells (KCs) but did not alter the proliferation of splenocytes. The protective effects of nicotine against ConA-induced hepatitis were abolished in KC-depleted mice, indicating the requirement of KCs in this process. Additionally, the expression of α7-nAChR on KCs was dramatically increased by nicotine treatment, and the protective effects of nicotine on ConA-induced liver injury were significantly suppressed by treatment with methyllycaconitine (MLA), a specific α7-nAChR antagonist. Consistently, in primary cultured KCs, the activation of NF-κB signaling was also regulated by nicotine treatment. This study suggests that nicotine increases α7-nAChR-mediated cholinergic activity in KCs resulting in decrease of ConA-induced autoimmune hepatitis through inhibiting NF-κB signaling.

The ellagitannin metabolite urolithin C is a glucose-dependent regulator of insulin secretion through activation of L-type calcium channels

BACKGROUND AND PURPOSE

The pharmacology of polyphenol metabolites on beta-cell function is largely undetermined. We sought to identify polyphenol metabolites that enhance the insulin-secreting function of beta-cells and to explore the underlying mechanisms.

EXPERIMENTAL APPROACH

INS-1 beta-cells and rat isolated islets of Langerhans or perfused pancreas preparations were used for insulin secretion experiments. Molecular modelling, intracellular Ca2+ monitoring, and whole-cell patch-clamp recordings were used for mechanistic studies.

KEY RESULTS

Among a set of polyphenol metabolites, we found that exposure of INS-1 beta-cells to urolithins A and C enhanced glucose-stimulated insulin secretion. We further characterized the activity of urolithin C and its pharmacological mechanism. Urolithin C glucose-dependently enhanced insulin secretion in isolated islets of Langerhans and perfused pancreas preparations. In the latter, enhancement was reversible when glucose was lowered from a stimulating to a non-stimulating concentration. Molecular modelling suggested that urolithin C could dock into the Cav 1.2 L-type Ca2+ channel. Calcium monitoring indicated that urolithin C had no effect on basal intracellular Ca2+ but enhanced depolarization-induced increase in intracellular Ca2+ in INS-1 cells and dispersed cells isolated from islets. Electrophysiology studies indicated that urolithin C dose-dependently enhanced the L-type Ca2+ current for levels of depolarization above threshold and shifted its voltage-dependent activation towards more negative potentials in INS-1 cells.

CONCLUSION AND IMPLICATIONS

Urolithin C is a glucose-dependent activator of insulin secretion acting by facilitating L-type Ca2+ channel opening and Ca2+ influx into pancreatic beta-cells. Our work paves the way for the design of polyphenol metabolite-inspired compounds aimed at ameliorating beta-cell function.

Hesperetin relieves cisplatin-induced acute kidney injury by mitigating oxidative stress, inflammation and apoptosis

Although cisplatin is an effective anticancer drug, its clinical application is limited due to various side effects, especially nephrotoxicity. In this study, we investigated the protective effects and possible mechanisms of hesperetin on cisplatin-induced kidney damage. In vitro, hesperetin significantly attenuated oxidative stress-induced apoptosis by reducing ROS levels in cisplatin-treated HK-2 cells. Simultaneously, hesperetin activated the Nrf2 signaling pathway and regulated its downstream genes, including NQO1 and HO-1. In vivo, hesperetin could significantly attenuate cisplatin-induced nephrotoxicity, blood urea nitrogen (BUN) and serum creatinine (SCr). Furthermore, hesperetin clarifies cisplatin-induced oxidative stress by reducing MDA/MPO levels and increasing SOD/GSH levels. In addition, from the histopathological analysis of the kidney, hesperetin significantly reduced the nephrotoxicity caused by cisplatin compared with the cisplatin group. Moreover, western blotting of renal tissue revealed that hesperetin activates Nrf2 in a dose-dependent manner, attenuates the MAPK signaling pathway against inflammation, and inhibits the expression of apoptotic proteins to protect kidneys from AKI caused by cisplatin. Altogether, these findings suggest that hesperetin may be a potential protectant against cisplatin-induced nephrotoxicity.

Methyl 3,4-dihydroxybenzoate protects against d-galN/LPS-induced acute liver injury by inhibiting inflammation and apoptosis in mice

Objectives

Aimed to investigate the effect and mechanism of methyl 3,4-dihydroxybenzoate (MDHB) on d-galactosamine/lipopolysaccharide (d-galN/LPS)-induced acute liver failure (ALF).

Methods

Confirmed the hepatoprotective effect and hepatotoxicity of MDHB by histopathological examination (HE) and examination of alanine aminotransferase (ALT) and aspartate aminotransferase (AST); the expression of serum tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) was detected by ELISA; transcription levels of TNF-α, IL-1β, IL-6 and Toll-like receptor 4 (TLR4) were detected by qRT-PCR; and phosphorylation levels of p38 and p65 were analysed by Western blot.

Results

Histopathological examination and examination of ALT and AST confirmed that MDHB is a low toxicity drug that can resist d-galN/LPS-induced ALF; MDHB can effectively reduce high transcription and expression of TNF-α, IL-1β, IL-6 and TLR4 in d-galN/LPS-induced ALF; and Western blot showed that MDHB could down-regulate the expression of bax, up-regulate the expression of bcl-xl and bcl-2, and inhibit the phosphorylation of p38 and p65.

Conclusions

Methyl 3,4-dihydroxybenzoate can effectively resist d-galN/LPS-induced acute liver failure, which is related to the inhibition of inflammation and apoptosis.

Hesperetin, a Citrus Flavonoid, Attenuates LPS-Induced Neuroinflammation, Apoptosis and Memory Impairments by Modulating TLR4/NF-κB Signaling

Glial activation and neuroinflammation play significant roles in apoptosis as well as in the development of cognitive and memory deficits. Neuroinflammation is also a critical feature in the pathogenesis of neurodegenerative disorders such as Alzheimer and Parkinson’s diseases. Previously, hesperetin has been shown to be an effective antioxidant and anti-inflammatory agent. In the present study, in vivo and in vitro analyses were performed to evaluate the neuroprotective effects of hesperetin in lipopolysaccharide (LPS)-induced neuroinflammation, oxidative stress, neuronal apoptosis and memory impairments. Based on our findings, LPS treatment resulted in microglial activation and astrocytosis and elevated the expression of inflammatory mediators such as phosphorylated-Nuclear factor-κB (p-NF-κB), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) in the cortical and hippocampal regions and in BV2 cells. However, hesperetin cotreatment markedly reduced the expression of inflammatory cytokines by ameliorating Toll-like receptor-4 (TLR4)-mediated ionized calcium-binding adapter molecule 1/glial fibrillary acidic protein (Iba-1/GFAP) expression. Similarly, hesperetin attenuated LPS-induced generation of reactive oxygen species/lipid per oxidation (ROS/LPO) and improved the antioxidant protein level such as nuclear factor erythroid 2-related factor 2 (Nrf2) and Haem-oxygenase (HO-1) in the mouse brain. Additionally, hesperetin ameliorated cytotoxicity and ROS/LPO induced by LPS in HT-22 cells. Moreover, hesperetin rescued LPS-induced neuronal apoptosis by reducing the expression of phosphorylated-c-Jun N-terminal kinases (p-JNK), B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax), and Caspase-3 protein and promoting the Bcl-2 protein level. Furthermore, hesperetin enhanced synaptic integrity, cognition, and memory processes by enhancing the phosphorylated-cAMP response element binding protein (p-CREB), postsynaptic density protein-95 (PSD-95), and Syntaxin. Overall, our preclinical study suggests that hesperetin conferred neuroprotection by regulating the TLR4/NF-κB signaling pathway against the detrimental effects of LPS.

Hesperetin ameliorates diabetic nephropathy in rats by activating Nrf2/ARE/glyoxalase 1 pathway

Diabetic nephropathy (DN) is one of the most common diabetic complications, and alpha-carbonyl aldehydes and their detoxicating enzyme glyoxalase 1 (Glo-1) play vital roles in pathogenesis of diabetic complications. The aim of this study was to evaluate the renoprotective effects of hesperetin against DN in rats, and to investigate mechanisms from the aspect of Nrf2/ARE/Glo-1 pathway. Streptozotocin-induced diabetic rats were treated orally with hesperetin (50 and 150 mg/kg), or nuclear factor erythroid-derived-2-like 2 (Nrf2) inducer tert-butylhydroquinone (tBHQ, 25 mg/kg) for 10 weeks. Then proteinuria, creatinine, urea nitrogen, and uric acid were assayed for renal functions, fibronectin and collagen IV levels by immunohistochemistry, as well as periodic acid-Schiff staining and electron microscope observation, were used to assess renal morphology. Glo-1 activity, protein, and mRNA levels and the classic Nrf2/ARE pathway were investigated. Moreover, advanced glycation endproducts (AGEs) and its receptor RAGE, interleukin-1β and tumor necrosis factor-α levels were also examined in the kidney. Hesperetin markedly ameliorated the renal functions and structural changes of diabetic rats, accompanied by up-regulation of Glo-1 as well as inhibition of AGEs/RAGE axis and inflammation. Meanwhile, hesperetin caused significant increases in Nrf2 and p-Nrf2 levels, as well as up-regulation of γ-glutamylcysteine synthetase, a well-known target gene of Nrf2/ARE signaling. Our results demonstrated that hesperetin could slow down the pathological process of DN, and Glo-1 enhancement contributed to the beneficial effects, which was obtained by the activation of Nrf2/ARE pathway.

Hesperetin, a citrus flavonoid, attenuates testicular damage in diabetic rats via inhibition of oxidative stress, inflammation, and apoptosis

AIM

This study was designed to assess the beneficial effect of hesperetin on diabetes-associated testicular injury in the rat.

MAIN METHODS

Oral treatment with hesperetin started 10 days after diabetes induction by streptozotocin (60 mg/kg, i.p.) for 46 days. Testicular damage was evaluated by histological evaluation of seminiferous tubules in addition to assessment of epididymal sperm count, motility, and viability. In addition, testicular biomarkers of apoptosis, inflammation, and oxidative stress were also determined.

KEY FINDINGS

Hesperetin treatment of diabetic group prevented body weight loss and reduced serum glucose in addition to improvement of serum testosterone. Additionally, hesperetin-treated diabetic group had lower levels of malondialdehyde (MDA), reactive oxygen species (ROS), protein carbonyl, DNA fragmentation, and caspase 3 activity as specific biomarkers of oxidative stress and/or apoptosis. Furthermore, hesperetin augmented testicular antioxidant system as shown by higher levels of glutathione (GSH), mitochondrial membrane potential (MMP), and ferric reducing antioxidant power (FRAP) in addition to improvement of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx). Moreover, hesperetin administration to diabetic rats attenuated testicular indices of inflammation consisting of tumor necrosis factor α (TNFα) and interleukin 17 (IL-17) and prevented damage of seminiferous tubules as revealed by higher levels of sperm count, motility, and viability in diabetic rats.

SIGNIFICANCE

Collectively, hesperetin could alleviate testicular damage in DM, at least through inhibition of apoptosis, oxidative stress, and inflammation in addition to its up-regulation of endogenous enzymatic and non-enzymatic antioxidants.

Hesperetin and it nanocrystals ameliorate social behavior deficits and oxido-inflammatory stress in rat model of autism

Prenatal exposure to valproic acid (VPA) induces behavioral disorders and enhancement of oxido-inflammatory stress in Autism Spectrum Disorders (ASDs). The aim of this study was to investigate the comparative effects of hesperetin (Hst) and nano-hesperetin on social behavior deficits and oxido-inflammatory indexes in prenatally valproic acid-exposed rat offspring. Pregnant Wistar rats on embryonic day 0 (E0) were segregated into six groups; Group-1 served as vehicle, received distillated water orally (PO) from E1 until the end of lactation and saline intraperitoneally (i.p) on E12.5. Group-2 received sodium valproate (500 mg/kg in 0.9% saline, i.p) on E12.5 was considered as VPA-exposed group, Group-3 to 6 were VPA-exposed which received hesperetin and nano-hesperetin (10 and 20 mg/kg/day, PO) from E0 until the end of lactation respectively. Social interaction and open field tests were conducted on postnatal day 28 (PND 28) and PND 30, cerebral antioxidant enzymes activity and biochemical indexes, the level of inflammatory factors in plasma and histopathology of cerebellum were estimated on PND 28 and PND 30. Prenatal valproic acid-exposed rat exhibited poor sociability and high level of anxiety-like behaviors (P <  0.05). In addition, increased level of oxidative stress and inflammation were found by determining different oxido-inflammatory markers. Hesperetin and nano-hesperetin treatment improved the behavioral disorder and reduced the oxidative stress in brain and significantly (p <  0.05) plasma's inflammation indexes. In conclusion, it can be state that nano-hesperetin exerts neuroprotective action in comparison with hesperetin and could be efficacious for treatment of VPA animal model of autism during pregnancy and lactation.

Citri Reticulatae Pericarpium (Chenpi): Botany, ethnopharmacology, phytochemistry, and pharmacology of a frequently used traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Citri Reticulatae Pericarpium (Rutaceae, CRP), commonly called as Chenpi () in Chinese, is most frequently used as a qi-regulating drug in thousands of Chinese medicine prescriptions. CRP is found mainly in major citrus-producing areas such as the Guangdong, Guangxi, Sichuan, Fujian, and Zhejiang Provinces of China. Since thousands of years in China, CRP has been used widely in clinical practice to treat nausea, vomiting, indigestion, anepithymia, diarrhea, cough, expectoration, and so on. Currently, CRP is listed in the Pharmacopoeia of the People's Republic of China. The present paper reviews the botany, ethnopharmacology, phytochemistry, pharmacology, quality control, and toxicology of CRP.

MATERIALS AND METHODS

Information on CRP was gathered from various sources including the books on traditional Chinese herbal medicine; scientific databases including Elsevier, PubMed, and ScienceDirect; Baidu Scholar; CNKI; and others and from different professional websites.

RESULTS

Approximately 140 chemical compounds have been isolated and identified from CRP. Among them, volatile oils and flavonoids are generally considered as the main bioactive and characteristic ingredients. CRP possesses wide pharmacological effects such as having a beneficial effect on the cardiovascular, digestive, and respiratory systems, antitumor, antioxidant, and anti-inflammatory properties; and a protective effect on the liver and nerve. Moreover, hesperidin is chosen as an indicator in the quantitative determination of CRP, and the quantity of aflatoxin in CRP must not exceed the standard limit mentioned in the pharmacopoeia.

CONCLUSIONS

In brief, CRP has a warming nature, and hence, it can be used in harmony with a lot of medicines. CRP not only exhibits its effects individually but also aids other medicines exhibit a better effect. CRP can be consumed with tea, food, alcohol, and medicine. Irrespective of the form it is being consumed, CRP not only shows a synergistic effect but also has strengths on its own. Modern pharmacological studies have demonstrated that CRP has marked bioactivities, especially on the diseases of the digestive and respiratory systems. The bioactivities of CRP are useful for its clinical application and provide prospects for the development of drugs as well as food and health products for people. Although CRP is a commonly used drug in the traditional Chinese herbal prescription, there is an urgent need for further research on its synergistic effect with other herbs based on the compatibility theory of TCM, which would further increase our understanding on the compatibility theory of TCM.

Identification of Aspergillus fumigatus UDP-Galactopyranose Mutase Inhibitors

Aspergillus fumigatus is an opportunistic human pathogen responsible for deadly, invasive infections in immunocompromised patients. The A. fumigatus cell wall is a complex network of polysaccharides among them galactofuran, which is absent in humans. UDP-galactopyranose mutase (UGM) catalyzes the conversion of UDP-galactofuranose (UDP-Galf) to UDP-galactopyranose (UDP-Galp) and is an important virulence factor. UGM is a flavin-dependent enzyme that requires the reduced flavin for activity; flavin reduction is achieved by reaction with NADPH. The aim of this work was to discover inhibitors of UGM by targeting the NADPH binding site using an ADP-TAMRA probe in a high-throughput screening assay. The flavonoids (2S)-hesperetin and (2S)-naringenin were validated as competitive inhibitors of UGM against NADPH with K_i values of 6 µM and 74 µM, respectively. To gain insight into the active chemical substituents involved in the inhibition of UGM, several derivatives of these inhibitors were studied. The results show that the hydroxyl groups of (2S)-hesperetin are important for inhibition, in particular the phenyl-chroman moiety. Congo red susceptibility assay and growth temperature effects showed that these compounds affected cell wall biosynthesis in A. fumigatus. This work is the first report of inhibition studies on UGM from eukaryotic human pathogens.

The protective effect of the natural compound hesperetin against fulminant hepatitis in vivo and in vitro

BACKGROUND AND PURPOSE

Liver diseases are mostly accompanied by inflammation and hepatocyte death. Therapeutic approaches targeting both hepatocyte injury and inflammation are not available. Natural compounds are considered as potential treatment for inflammatory liver diseases. Hesperetin, a flavonoid component of citrus fruits, has been reported to have anti-inflammatory properties. The aim of this study was to evaluate the cytoprotective and anti-inflammatory properties of hesperetin both in vitro and in models of fulminant hepatitis.

EXPERIMENTAL APPROACH

Apoptotic cell death and inflammation were induced in primary cultures of rat hepatocytes by bile acids and cytokine mixture respectively. Apoptosis was quantified by caspase-3 activity and necrosis by LDH release. The concanavalin A (ConA) and D-galactosamine/LPS (D-GalN/LPS) were used as models of fulminant hepatitis. Liver injury was assessed by alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, liver histology and TUNEL assay and inflammation by inducible NOS (iNOS) expression.

KEY RESULTS

Hesperetin blocked bile acid-induced apoptosis and cytokine-induced inflammation in rat hepatocytes. Moreover, hesperetin improved liver histology and protected against hepatocyte injury in ConA- and D-GalN/LPS-induced fulminant hepatitis, as assessed by TUNEL assay and serum AST and ALT levels. Hesperetin also reduced expression of the inflammatory marker iNOS and the expression and serum levels of TNFα and IFN-γ, the main mediators of cell toxicity in fulminant hepatitis.

CONCLUSION AND IMPLICATIONS

Hesperetin has anti-inflammatory and cytoprotective actions in models of acute liver toxicity. Hesperetin therefore has therapeutic potential for the treatment of inflammatory liver diseases accompanied by extensive hepatocyte injury, such as fulminant hepatitis.