Antifibrotic activity of hesperidin against dimethylnitrosamine-induced liver fibrosis in rats

Mixed micelles loaded with hesperidin protect against acetaminophen induced acute liver injury by inhibiting the mtDNA-cGAS-STING pathway

Excessive acetaminophen (APAP) is the main cause of drug-induced acute liver failure, and the pathogenesis has not been elucidated and there is a lack of effective drugs. Hesperidin (Hes), a rich flavanone in citrus peel with excellent biological activities, is a potential agent for treatment liver injury. Due to poor water solubility of Hes, this study prepared mixed micelles using polyvinyl pyrrolidone (PVP K17) and poloxamer 188, and encapsulated Hes (Hes-MMs). The results showed that Hes-MMs exhibited a uniform spherical shape with a particle size of 66.80 ± 0.83 nm, and Hes-MMs significantly improved the dispersibility, antioxidant activity, and cellular uptake of Hes. In vitro results showed that Hes-MMs protected the proliferation inhibition of HepG2 cells induced by APAP, inhibited the production of reactive oxygen species (ROS) and the damage of mitochondrial membrane potential (MMP) induced by APAP. Furthermore, Hes-MMs exerted liver protective effects by inhibiting APAP induced mtDNA release and activating the cGAS-STING pathway. In vivo results demonstrated that Hes-MMs showed protective and therapeutic effects on APAP induced liver injury, and their mechanisms were related to the mtDNA-cGAS-STING signaling pathway. In summary, our study demonstrated that the mtDNA-cGAS-STING pathway was involved in APAP induced acute liver injury, and Hes-MMs might be a potential therapeutic agent for treating APAP induced acute liver injury.

Application of the Mannich reaction in the structural modification of natural products

The Mannich reaction is commonly used to introduce N atoms into compound molecules and is thus widely applied in drug synthesis. The Mannich reaction accounts for a certain proportion of structural modifications of natural products. The introduction of Mannich bases can significantly improve the activity, hydrophilicity, and medicinal properties of compounds; therefore, the Mannich reaction is widely used for the structural modification of natural products. In this paper, the application of the Mannich reaction to the structural modification of natural products is reviewed, providing a method for the structural modification of natural products.

A review of edible plant-derived natural compounds for the therapy of liver fibrosis

Liver fibrosis has a high incidence worldwide and is the common pathological basis of many chronic liver diseases. Liver fibrosis is caused by the excessive deposition of extracellular matrix and concomitant collagen accumulation in livers and can lead to the development of liver cirrhosis and even liver cancer. A large number of studies have provided evidence that liver fibrosis can be blocked or even reversed by appropriate medical interventions. However, the antifibrosis drugs with ideal clinical efficacy are still insufficient. The edible plant-derived natural compounds have been reported to exert effective antifibrotic effects with few side-effects, representing a kind of promising source for the treatment of liver fibrosis. In this article, we reviewed the current progress of the natural compounds derived from dietary plants in the treatment of liver fibrosis, including phenolic compounds (capsaicin, chlorogenic acid, curcumin, ellagic acid, epigallocatechin-3-gallate, resveratrol, sinapic acid, syringic acid, vanillic acid and vitamin E), flavonoid compounds (genistein, hesperidin, hesperetin, naringenin, naringin and quercetin), sulfur-containing compounds (S-allylcysteine, ergothioneine, lipoic acid and sulforaphane) and other compounds (betaine, caffeine, cucurbitacin B, lycopene, α-mangostin, γ-mangostin, ursolic acid, vitamin C and yangonin). The pharmacological effects and related mechanisms of these compounds in in-vivo and in-vitro models of liver fibrosis are focused.

The Preventive and Therapeutic Potential of the Flavonoids in Liver Cirrhosis: Current and Future Perspectives

Non-alcoholic fatty liver disease (NAFLD) may vary from moderately mild non-alcohol fatty liver (NAFL) towards the malignant variant known as non-alcoholic steatohepatitis (NASH), which is marked by fatty liver inflammation and may progress to liver cirrhosis (LC), liver cancer, fibrosis, or liver failure. Flavonoids can protect the liver from toxins through their anti-inflammatory, antioxidant, anti-cancer, and antifibrogenic pharmacological activities. Furthermore, flavonoids protect against LC by regulation of hepatic stellate cells (HSCs) trans-differentiation, inhibiting growth factors like TGF-β and platelets-derived growth factor (PDGF), vascular epithelial growth factor (VEGF), viral infections like hepatitis-B, C and D viruses (HBV, HCV & HDV), autoimmune-induced, alcohol-induced, metabolic disorder-induced, causing by apoptosis, and regulating MAPK pathways. These flavonoids may be explored in the future as a therapeutic solution for hepatic diseases.

Efficiency of Hesperidin against Liver Fibrosis Induced by Bile Duct Ligation in Rats

Introduction

Bile duct ligation (BDL) and subsequent cholestasis are associated with oxidative stress and liver injury and fibrosis. Hesperidin (3,5,7-trihydroxyflavanone 7-rhamnoglucoside) is a flavanone glycoside abundant in citrus fruits. It has positive effects on diabetic retinopathy, reduced platelet aggregation, and blood flow alterations and has the potential to reduce liver injury in oxidative stress. The aim of this study was to evaluate the hepatoprotective effects of hesperidin on BDL-induced liver injury in rats.

Methods

A total of 48 adult male Wistar rats were equally allocated to six eight-rat groups, namely, a healthy group, a sham group, a BDL+Vehicle group (BDL plus treatment with distilled water), a BDL+VitC group (BDL plus treatment with vitamin C 4.25 μg/kg), a BDL+Hesp100 group (BDL plus treatment with hesperidin 100 mg/kg/day), and a BDL+Hesp200 group (BDL plus treatment with hesperidin 200 mg/kg/day). Treatments were orally provided for 21 consecutive days. Finally, rats were sacrificed through heart blood sampling. Blood samples were centrifuged, and liver function, oxidative stress, and antioxidant parameters were assessed. Liver tissue was also assessed for oxidative stress, antioxidant, and histological parameters. The expression of inflammatory genes, namely, TGFβ1, iNOS, Caspase-3, and α-SMA, was measured through polymerase chain reaction. Findings. Hesperidin supplementation was associated with significant decrease in the levels of liver enzymes, bilirubin, nitric oxide, malondialdehyde, protein carbonyl, and inflammatory gene expression; significant increase in the levels of total antioxidant capacity, glutathione, and superoxide dismutase and catalase enzyme activity; and significant improvement in the histological morphology and structure of the liver parenchyma.

Conclusion

Hesperidin has significant positive effects on liver morphology and structure, inflammation, fibrosis, and oxidative stress in rats with BDL-induced cholestatic liver injury.

Khalaf AA, R. Zaki A, Mansour Khalifa M, A. Ibrahim M, M. Mekkawy A, E. Abdelrahman R, Farghali A, A. Noshy P. Hesperidin protects rats’ liver and kidney from oxidative damage and physiological disruption induced by nickel oxide nanoparticles

Background: Nickel oxide nanoparticles (NiO-NPs) have recently been utilized in various advanced industrial fields like lithium-ion micro batteries, nanofibers, electrochromic devices, and several biomedical applications. NiO-NPs are classified as extremely toxic substances as they can cause long-term harm to the environment and aquatic life. Moreover, frequent and prolonged exposure can affect human and animal health, causing skin allergies and major toxic consequences, such as hepatorenal toxicity. Hesperidin (HSP) has been proven to possess anti-inflammatory, antioxidant, and free radical scavenging activities.

Objective: This study aimed to investigate the underlying protective mechanisms and effects of HSP against NiO-NPs-induced hepatorenal toxicities in rats.

Materials and Methods: Forty male Wistar rats were randomly divided into four groups (n = 10 in each). The first group served as a Control group. For 8 weeks, the second group was administered NiO-NPs (100 mg/kg/day), and the third group was given HSP (100 mg/kg/day) via oral gavage for both groups. The fourth group received NiO-NPs and HSP concurrently in the same oral daily doses and duration as the second and third groups.

Results: NiO-NPs administration revealed a significant increase in plasma biomarkers of nephrotoxicity (urea, creatinine) and hepatotoxicity (ALT, AST) in NiO-NPs group compared to Control group (p < 0.05). In addition, NiO-NPs administration resulted in a substantial increase in malondialdehyde levels with a significant drop in catalase activity and GSH content in Group II. Also, a significant decreased expression of Nrf-2 and Bcl-2 mRNA levels and upregulation of TNF-α, NF-kβ and BAX in the liver and kidney of NiO-NPs group were also detected. Histologically, the liver and kidney of rats of NiO-NPs group showed significant histopathological disturbances, with a substantial increase in the proliferating cell nuclear antigen (PCNA) positive hepatocytes and renal tubular cells in the NiO-NPs group compared to Control and HSP groups (p < 0.05). In contrast, concomitant administration of HSP with NiO-NPs in group IV showed a significant biochemical, histopathological, and immunohistochemical improvement compared to NiO-NPs group.

Conclusion: Co-administration of HSP with NiO-NPs significantly ameliorated most of the NiO-NPs-induced hepatorenal toxicities in male rats.

Antioxidant and Antitumor Activities of Newly Synthesized Hesperetin Derivatives

Hesperetin is a class of natural products with a wide range of sources and remarkable biological activities. In this study, we described the synthesis of a series of novel hesperetin derivatives and evaluated the in vitro antioxidant and antitumor activity of these compounds. Eleven novel compounds were synthesized in moderate yields. The compounds synthesized in this work exhibited antioxidant activities against DPPH and ABTS free radicals in a dose-dependent manner. Among them, compound 3f had the best antioxidant activity, with IC₅₀ of 1.2 μM and 24 μM for DPPH and ABTS, respectively. The antitumor activity of the compounds against human cancer cell lines, such as breast MCF-7, liver HepG2, and cervical Hela, was determined by a standard 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Three compounds had moderate IC₅₀ values. Interestingly, compound 3f had better biological activity than hesperetin, which matches the prediction by Maestro from Schrödinger. Therefore, the new hesperidin derivative is a promising drug for the treatment of cancer due to its effective antitumor activity. The results also suggested that the antitumor activities of hesperetin derivatives may be related to their antioxidant activities.

Therapeutic potential of targeting regulatory mechanisms of hepatic stellate cell activation in liver fibrosis

Hepatic fibrosis is a manifestation of different etiologies of liver disease with the involvement of multiple mediators in complex network interactions. Activated hepatic stellate cells (aHSCs) are the central driver of hepatic fibrosis, given their potential to induce connective tissue formation and extracellular matrix (ECM) protein accumulation. Therefore, identifying the cellular and molecular pathways involved in the activation of HSCs is crucial in gaining mechanistic and therapeutic perspectives to more effectively target the disease. In addition to a comprehensive summary of our current understanding of the role of HSCs in liver fibrosis, we also discuss here the proposed therapeutic strategies based on targeting HSCs.

Piperlongumine attenuates bile duct ligation-induced liver fibrosis in mice via inhibition of TGF-β1/Smad and EMT pathways

Liver fibrosis (LF) is a progressive liver injury that may result in excessive accumulation of extracellular matrix (ECM). However, transforming growth factor-beta (TGF-β) and epithelial to mesenchymal transition (EMT) play a central role in the progression of LF through the activation of matrix producing hepatic stellate cells (HSCs). Piperlongumine (PL), an alkaloid extracted from Piper longum, has been reported to possess anti-inflammatory and antioxidant activities in various diseases but its hepatoprotective and antifibrotic effects have not been reported yet. Therefore, in the present study, we investigated the protective effect of PL in bile duct ligation (BDL)-induced LF model and explored the molecular mechanisms underlying its antifibrotic effect. BDL group displayed a significant degree of liver damage, oxidative-nitrosative stress, hepatic inflammation and collagen deposition in the liver while these pathological changes were effectively attenuated by treatment with PL. Furthermore, we found that PL treatment greatly inhibited HSCs activation and ECM deposition via downregulation of fibronectin, α-SMA, collagen1a, and collagen3a expression in the fibrotic livers. We further demonstrated that PL administration significantly inhibited TGF-β1/Smad and EMT signaling pathways. Our study demonstrated that PL exerted strong hepatoprotective and antifibrotic activities against BDL-induced LF and might be an effective therapeutic agent for the treatment of LF.

A Comprehensive Review of Natural Products against Liver Fibrosis: Flavonoids, Quinones, Lignans, Phenols, and Acids

Liver fibrosis resulting from continuous long-term hepatic damage represents a heavy burden worldwide. Liver fibrosis is recognized as a complicated pathogenic mechanism with extracellular matrix (ECM) accumulation and hepatic stellate cell (HSC) activation. A series of drugs demonstrate significant antifibrotic activity in vitro and in vivo. No specific agents with ideally clinical efficacy for liver fibrosis treatment have been developed. In this review, we summarized the antifibrotic effects and molecular mechanisms of 29 kinds of common natural products. The mechanism of these compounds is correlated with anti-inflammatory, antiapoptotic, and antifibrotic activities. Moreover, parenchymal hepatic cell survival, HSC deactivation, and ECM degradation by interfering with multiple targets and signaling pathways are also involved in the antifibrotic effects of these compounds. However, there remain two bottlenecks for clinical breakthroughs. The low bioavailability of natural products should be improved, and the combined application of two or more compounds should be investigated for more prominent pharmacological effects. In summary, exploration on natural products against liver fibrosis is becoming increasingly extensive. Therefore, natural products are potential resources for the development of agents to treat liver fibrosis.

Flavonoids from Aurantii Fructus Immaturus and Aurantii Fructus: promising phytomedicines for the treatment of liver diseases

Background

Liver diseases and related complications are major sources of morbidity and mortality, which places a huge financial burden on patients and lead to nonnegligible social problems. Therefore, the discovery of novel therapeutic drugs for the treatment of liver diseases is urgently required. Aurantii Fructus Immaturus (AFI) and Aurantii Fructus (AF) are frequently used herbal medicines in traditional Chinese medicine (TCM) formulas for the treatment of diverse ailments. A variety of bioactive ingredients have been isolated and identified from AFI and AF, including alkaloids, flavonoids, coumarins and volatile oils.

Main body

Emerging evidence suggests that flavonoids, especially hesperidin (HD), naringenin (NIN), nobiletin (NOB), naringin (NRG), tangeretin (TN), hesperetin (HT) and eriodictyol (ED) are major representative bioactive ingredients that alleviate diseases through multi-targeting mechanisms, including anti-oxidative stress, anti-cytotoxicity, anti-inflammation, anti-fibrosis and anti-tumor mechanisms. In the current review, we summarize the recent progress in the research of hepatoprotective effects of HD, NIN, NOB, NRG, TN, HT and ED and highlight the potential underlying molecular mechanisms. We also point out the limitations of the current studies and shed light on further in-depth pharmacological and pharmacokinetic studies of these bioactive flavonoids.

Conclusion

This review outlines the recent advances in the literature and highlights the potential of these flavonoids isolated from AFI and AF as therapeutic agents for the treatment of liver diseases. Further pharmacological studies will accelerate the development of natural products in AFI and AF and their derivatives as medicines with tantalizing prospects in the clinical application.

A review of the hepatoprotective effects of hesperidin, a flavanon glycoside in citrus fruits, against natural and chemical toxicities

OBJECTIVES

Liver is the most important and functional organ in the body to metabolize and detoxify endogenous compounds and xenobiotics. The major goal of the present narrative review is to assess the hepatoprotective properties of hesperidin against a variety of natural and chemical hepatotoxins via different mechanisms.

EVIDENCE ACQUISITION

Scientific databases such as Scopus, Medline, Web of Science and Google scholar were thoroughly searched, based on different keywords.

RESULTS

A variety of natural hepatotoxins such as lipopolysaccharide, concanavalin A and microcystins, and chemical hepatotoxins such as ethanol, acrylamide and carbon tetrachloride have been shown to damage hepatocytes as well as other liver cells. In addition to hepatocytes, ethanol can also damage liver hepatic stellate cells, Kupffer cells and sinusoidal endothelial cells. In this regard, the flavanone hesperidin, occur in the rind of citrus fruits, had been demonstrated to possess widespread pharmacological properties. Hesperidin exerts its hepatoprotective properties via different mechanisms including elevation in the activities of nuclear factor-like 2/antioxidant response element and heme oxygenase 1 as well as the levels of enzymatic and non-enzymatic antioxidants. Furthermore, reduction in the levels of high-mobility group box 1 protein, inhibitor of kappa B protein-alpha, matrix metalloproteinase-9 and C-reactive protein are some other important hesperidin-derived hepatoprotective mechanisms.

CONCLUSION

Based on several research papers, it could be concluded that hesperidin is able to protect against liver damage from inflammation and/or oxidative stress-mediated natural and chemical toxins.

Protective effects of hesperidin against MTX-induced hepatotoxicity in male albino rats

Hesperidin (HD), a bioflavonoid, has been shown to exert hepatoprotective effects. Our aim is to investigate the possible protective effects of HD against methotrexate (MTX) hepatotoxicity in adult male Sprague-Dawley (SD) rats that were divided into four groups (10 rats/each) and were exposed to MTX with or without HD co-administration for consecutive 28 days. The results showed that HD significantly ameliorated MTX-induced increase in liver enzymes and histopathological changes. Hepatic oxidative stress was suppressed by HD, as evidenced by the decrease in malondialdehyde (MDA), with a concomitant increase in total antioxidant activity (TAC), catalase (CAT), and glutathione (GSH) levels. Moreover, co-administration of HD with MTX remarkably upregulated the expression of Nrf2 and HO-1 compared with the MTX group. By the decrease in nuclear factor-kB (NF-κB) pathway and tumor necrosis factor α (TNF-α), HD obviously attenuated inflammatory response in MTX-lesioned livers. Likewise, the downregulation of P53 by HD could explain its antiapoptotic effects as indicated by increase BCl2 and the significant decrease of caspase-9 mRNA expression as compared with the MTX group. Thus, these findings revealed the hepatoprotective nature of HD against MTX hepatotoxicity by attenuating the pro-inflammatory and apoptotic mediators and improving antioxidant aptitude.

Effects of Hesperidin on H₂O₂-Treated Chondrocytes and Cartilage in a Rat Osteoarthritis Model

Background

The purpose of this research was to investigate the effects of hesperidin on hydrogen peroxide (H₂O₂)-induced chondrocytes injury and cartilage degeneration in a rat model of osteoarthritis (OA).

Material/Methods

Chondrocytes were isolated from rat knee joints and treated with hesperidin alone or combined with H₂O₂. Then, Cell Counting Kit-8 (CCK-8) assay was used to assess cell viability. Activity of reactive oxygen species (ROS) and levels of malondialdehyde (MDA) were estimated. Cell apoptosis was assessed by flow cytometry assay. In addition, gene expression levels were measured for caspase 3, tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), collagen type II (Col2a1), aggrecan, (sex-determining region Y)-box 9 (SOX9), matrix metalloproteinase (MMP)-13, and inducible nitric oxide synthase (iNOS) through quantitative real-time polymerase chain reaction (qPCR). To examine the effects on cartilage destruction in vivo, hesperidin or vehicle control were orally administrated in a surgically-induced osteoarthritis (OA) model.

Results

The results indicated that hesperidin pretreatment of chondrocytes reduce H₂O₂-induced cytotoxicity and apoptosis. Hesperidin pretreatment decreased the formation of MDA and intracellular ROS, including chondrocyte apoptosis. Hesperidin also reversed the activity of H₂O₂ on inhibiting the Col2a1, aggrecan, and SOX9 gene expression and increasing the gene expression of caspase 3, IL-1β, TNFα, iNOS, and MMP13. In addition, hesperidin administration markedly attenuated cartilage destruction and reduced IL-1β and TNF-α levels in a surgically-induced OA model.

Conclusions

Our study suggests that hesperidin can prevent H₂O₂-induced chondrocytes injury through its antioxidant effects in vitro and reduce cartilage damage in a rat model of OA.

Sildenafil protects against bile duct ligation induced hepatic fibrosis in rats: Potential role for silent information regulator 1 (SIRT1)

Hepatic fibrosis is a potential health problem that may end with life-threatening cirrhosis and primary liver cancer. Recent studies point out to the protective effects of silent information regulator1 (SIRT1), against different models of organs fibrosis. This work aimed to investigate the possible protective effect of sildenafil (SIRT1 activator) against hepatic fibrosis induced by bile duct ligation (BDL). Firstly, three different doses of sildenafil (5, 10, 20mg/kg/day) were investigated; to detect the most protective one against BDL induced liver dysfunction and hepatic fibrosis. The most protective dose is then used; to study its effect on BDL induced SIRT1 downregulation, imbalance of oxidant/antioxidant status, increased inflammatory cytokines and fibrosis. Sildenafil (20mg/kg/day) was the most protective one, it caused upregulation of SIRT1, reduction of hepatic malondialdehyde (MDA) content, increase in expression of nuclear factor erythroid 2-related factor 2 (Nrf2), hemeoxygenease (HO)-1, reduced glutathione (GSH) content and superoxide dismutase (SOD) activity. Hepatic content of tumor necrosis factor-α (TNF-α) and nuclear factor κB (NFκB) expression & content displayed significant reductions with sildenafil treatment, Furthermore, sildenafil caused marked reductions of transforming growth factor (TGF)-β content, expression of plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), α-smooth muscle actin (α-SMA), fibronectin, collagen I (α1) and hydroxyproline content. However, sildenafil protective effects were significantly reduced by co-administration of EX527 (SIRT1 inhibitor). Our work showed, for the first time that, sildenafil has promising protective effects against BDL induced liver dysfunction and hepatic fibrosis. These effects may be, in part, mediated by up regulation of SIRT1.

Design, synthesis and biological evaluation of hesperetin derivatives as potent anti-inflammatory agent

A flavonoid hesperetin is reported to have a variety of biological activities, including anticancer, antiviral, antioxidant, neuroprotective and anti-inflammatory properties. Thirty-one novel hesperetin derivatives were designed, synthesized and evaluated for anti-inflammatory activity using RAW264.7 cells and CCl4-induced acute liver injury model. Among these compounds, 5b displayed the excellent anti-inflammatory activity on decreasing NO, IL-6 and TNF-α both in vitro and vivo. In addition, 5b could also reduce the release of NO, IL-6 and TNF-α production by LPS stimulated RAW 264.7 cell through MAPK and NF-κB signaling pathway in a concentration dependent manner. From in vivo study, it was also observed that 5b attenuated liver histopathologic changes in mouse models.

Design, Synthesis and Evaluation of Hesperetin Derivatives as Potential Multifunctional Anti-Alzheimer Agents

In this study we designed and synthesized a series of new hesperetin derivatives on the basis of the structural characteristics of acetylcholinesterase (AChE) dual-site inhibitors. The activity of the novel derivatives was also evaluated. Results showed that the synthesized hesperetin derivatives displayed stronger inhibitory activity against AChE and higher selectivity than butyrylcholine esterase (BuChE) (selectivity index values from 68 to 305). The Lineweaver-Burk plot and molecular docking study showed that these compounds targeted both the peripheral anionic site (PAS) and catalytic active site (CAS) of AChE. The derivatives also showed a potent self-induced β-amyloid (Aβ) aggregation inhibition and a peroxyl radical absorbance activity. Moreover, compound 4f significantly protected PC12 neurons against H₂O₂-induced cell death at low concentrations. Cytotoxicity assay showed that the low concentration of the derivatives does not affect the viability of the SH-SY5Y neurons. Thus, these hesperetin derivatives are potential multifunctional agents for further development for the treatment of Alzheimer's disease.

Dietary Flavonoid Hyperoside Induces Apoptosis of Activated Human LX-2 Hepatic Stellate Cell by Suppressing Canonical NF-κB Signaling

Hyperoside, an active compound found in plants of the genera Hypericum and Crataegus, is reported to exhibit antioxidant, anticancer, and anti-inflammatory activities. Induction of hepatic stellate cell (HSC) apoptosis is recognized as a promising strategy for attenuation of hepatic fibrosis. In this study, we investigated whether hyperoside treatment can exert antifibrotic effects in human LX-2 hepatic stellate cells. We found that hyperoside induced apoptosis in LX-2 cells and decreased levels of α-smooth muscle actin (α-SMA), type I collagen, and intracellular reactive oxygen species (ROS). Remarkably, hyperoside also inhibited the DNA-binding activity of the transcription factor NF-κB and altered expression levels of NF-κB-regulated genes related to apoptosis, including proapoptotic genes Bcl-Xs, DR4, Fas, and FasL and anti-apoptotic genes A20, c-IAP1, Bcl-X_L, and RIP1. Our results suggest that hyperoside may have potential as a therapeutic agent for the treatment of liver fibrosis.

Involvement of splenic iron accumulation in the development of nonalcoholic steatohepatitis in Tsumura Suzuki Obese Diabetes mice

Nonalcoholic steatohepatitis (NASH) is a common hepatic manifestation of metabolic syndrome and can lead to hepatic cirrhosis and cancer. It is considered that NASH is caused by multiple parallel events, including abnormal lipid metabolism, gut-derived-endotoxin-induced inflammation, and adipocytokines derived from adipose tissue, suggesting that other tissues are involved in NASH development. Previous studies demonstrated that spleen enlargement is observed during the course of NASH pathogenesis. However, the involvement of splenic status in the progression of NASH remains unclear. In this study, we examined hepatic and splenic histopathological findings in the early stage of NASH using the Tsumura Suzuki Obese Diabetes (TSOD) mouse model established for assessing NASH. We found that 12-week-old TSOD mice clearly exhibited the histopathological features of NASH in the early stage. At this age, the spleen of TSOD mice showed markedly higher iron level than that of control Tsumura Suzuki Non Obesity (TSNO) mice. The level of accumulated iron was significantly decreased by feeding a diet with glucosyl hesperidin, a bioactive flavonoid, accompanied with alleviation of hepatic lesions. Furthermore, we found that splenic iron level was positively correlated with the severity of NASH manifestations, suggesting that abnormalities in the spleen are involved in the development of NASH.

Hesperetin derivatives: Synthesis and anti-inflammatory activity

Sixteen novel hesperetin derivatives containing Mannich base moiety were designed and synthesized and their anti-inflammatory activities were evaluated by inhibiting tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in mouse RAW264.7 macrophages. Compounds 3a-3k showed better hydrophilic, while compounds 3l-3p with aromatic groups was hydrophobic. The anti-inflammatory activity of title compounds was correlated with logP values, among them, compounds 3c, 3e and 3i with minus logP values exhibited best anti-inflammatory activity through decreasing both IL-6 and TNF-α. Furthermore, the expression of LPS-induced notch1 and inos was reduced by compounds 3c, 3e, and 3i, and compound 3e attenuated LPS-induced inos protein levels in a dose-dependent manner.

Natural antioxidants for non-alcoholic fatty liver disease: molecular targets and clinical perspectives

Non-alcoholic steatohepatitis (NASH), the progressive form of non-alcoholic fatty liver disease (NAFLD), is emerging as a main health problem in industrialized countries. Lifestyle modifications are effective in the treatment of NAFLD; however, the long-term compliance is low. Therefore, several pharmacological treatments have been proposed but none has shown significant efficacy or long-term safety. Natural polyphenols are a heterogeneous class of polyphenolic compounds contained in vegetables, which are being proposed for the treatment of different metabolic disorders. Although the beneficial effect of these compounds has traditionally related to their antioxidant properties, they also exert several beneficial effects on hepatic and extra-hepatic glucose and lipid homeostasis. Furthermore, natural polyphenols exert antifibrogenic and antitumoural effects in animal models, which appear relevant from a clinical point of view because of the association of NASH with cirrhosis and hepatocellular carcinoma. Several polyphenols, such anthocyanins, curcumin and resveratrol and those present in coffee, tea, soy are available in the diet and their consumption can be proposed as part of a healthy diet for the treatment of NAFLD. Other phenolic compounds, such as silymarin, are commonly consumed worldwide as nutraceuticals or food supplements. Natural antioxidants are reported to have beneficial effects in preclinical models of NAFLD and in pilot clinical trials, and thus need clinical evaluation. In this review, we summarize the existing evidence regarding the potential role of natural antioxidants in the treatment of NAFLD and examine possible future clinical applications.

Protective effects of flavonoids against microbes and toxins: The cases of hesperidin and hesperetin

Many plants produce flavonoids as secondary metabolites. These organic compounds may be involved in the defense against plant-threatening factors, such as microbes and toxins. Certain flavonoids protect their origin source against plant pathogens, but they also exhibit potential healthy properties in human organisms. Hesperidin (Hsd) and its aglycone, hesperetin (Hst), are two flavonoids from the Citrus species that exhibit various biological properties, including antioxidant, antiinflammatory and anticancer effects. Recent studies indicated that Hst and Hsd possess antimicrobial activity. Although the exact mechanisms behind their antimicrobial properties are not fully understood, several mechanisms such as the activation of the host immune system, bacterial membrane disruption, and interference with microbial enzymes, have been proposed. Hsd and Hst may also have protective effects against toxicity induced by various agents. These natural substances may contribute to the protection of cells and tissues through their antioxidant and radical scavenging activities. This review discusses the protective activities of Hsd and Hst against microbes and several toxicities induced by oxidants, chemicals, toxins, chemotherapy and radiotherapy agents, which were reported in vitro and in vivo. Furthermore, the probable mechanisms behind these activities are discussed.