Hesperetin: A Potent Antioxidant Against Peroxynitrite

Recent understanding of the mechanisms of the biological activities of hesperidin and hesperetin and their therapeutic effects on diseases

Flavonoids are natural phytochemicals that have therapeutic effects and act in the prevention of several pathologies. These phytochemicals can be found in lemon, sweet orange, bitter orange, clementine. Hesperidin and hesperetin are citrus flavonoids from the flavanones subclass that have anti-inflammatory, antioxidant, antitumor and antibacterial potential. Preclinical studies and clinical trials demonstrated therapeutical effects of hesperidin and its aglycone hesperetin in various diseases, such as bone diseases, cardiovascular diseases, neurological diseases, respiratory diseases, digestive diseases, urinary tract diseases. This review provides a comprehensive overview of the biological activities of hesperidin and hesperetin, their therapeutic potential in various diseases and their associated molecular mechanisms. This article also discusses future considerations for the clinical applications of hesperidin and hesperetin.

Antioxidant responses driven by Hesperetin and Hesperidin counteract Parkinson's disease-like phenotypes in Drosophila melanogaster

The study investigated the protective effects of Hesperetin (HSP) and Hesperidin (HSD) on 1 methyl, 4 phenyl, 1,2,3,6 tetrahydropyridine hydrochloride (MPTP)-induced Parkinsonism in Drosophila melanogaster (D. melanogaster). After a lifespan study to select exposure time and concentrations, flies were co-exposed to MPTP (0.4 mg/g diet), Hesperetin (0.2 and 0.4 mg/g diet), and Hesperidin (0.1 and 0.4 mg/g) for 7 days. In addition to in vivo parameters, we assayed some markers of oxidative stress and antioxidant status (lipid peroxidation, protein carbonylation, thiol content, hydrogen peroxide, and nitrate/nitrite levels, mRNA expression of Keap-1 (Kelch-like ECH associated protein 1), /Nrf2 (Nuclear factor erythroid 2 related factor 2), catalase, and glutathione-S-transferase (GST) activities), and cholinergic (acetyl cholinesterase activity (AChE) and dopaminergic signaling content and the mRNA expression of tyrosine hydroxylase (TH), monoamine oxidase (MAO-like) activity). In addition to increasing the lifespan of flies, we found that both flavonoids counteracted the adverse effects of MPTP on survival, offspring emergence, and climbing ability of flies. Both flavonoids also reduced the oxidative damage on lipids and proteins and reestablished the basal levels of pro-oxidant species and activities of antioxidant enzymes in MPTP-exposed flies. These responses were accompanied by the normalization of the mRNA expression of Keap1/Nrf2 disrupted in flies exposed to MPTP. MPTP exposure also elicited changes in mRNA expression and content of TH as well as in MAO and AChE activity, which were reversed by HST and HSD. By efficiently hindering the oxidative stress in MPTP-exposed flies, our findings support the promising role of Hesperetin and Hesperidin as adjuvant therapy to manage Parkinsonism induced by chemicals such as MPTP.

Effect of postharvest processing on quality traits of Radix Gentianae Macrophyllae: A integrative analysis of metabolomics and proteomics

The dried roots and rhizomes of Radix Gentianae Macrophyllae are widely used as food material or medicinal crops. "Sweating" is a traditional postharvest processing method, the basic processing procedure consists of softening, stacking and drying. The aim of this paper is to unveil the scientific connotation responsible for the "Sweating" processing in Radix Gentianae Macrophyllae during postharvest. Thus, the effect of different postharvest processing methods on the metabolic pathways of Radix Gentiasnae Macrophyllae was studied by the non-targeted metabolomic technique in combination with the label-free proteomics approach. The results showed that the differentially accumulated metabolites and abundant proteins were mainly enriched in the pathways of phenylalanine, tyrosine and tryptophan biosynthesis, polyphenols and terpenoids biosynthesis. "Sweating" has a greater up-regulation effect on these pathways than "Non-sweating", and can induce protein expression and metabolite accumulation associated with the quality traits of Radix Gentianae Macrophyllae. The results provide a detailed explanation of the scientific connotation of crucial steps of "Sweating" processing wherein opportunities existed for taking appropriate measures to enhance the accumulation of bioactive ingredients. These findings will serve as significant references for enhancing the postharvest processing technology of Radix Gentianae Macrophyllae and similar plants, resulting in higher product quality for food or plant materials production.

Hesperetin and Capecitabine Abate 1,2 Dimethylhydrazine-Induced Colon Carcinogenesis in Wistar Rats via Suppressing Oxidative Stress and Enhancing Antioxidant, Anti-Inflammatory and Apoptotic Actions

Colon cancer is a major cause of cancer-related death, with significantly increasing rates of incidence worldwide. The current study was designed to evaluate the anti-carcinogenic effects of hesperetin (HES) alone and in combination with capecitabine (CAP) on 1,2 dimethylhydrazine (DMH)-induced colon carcinogenesis in Wistar rats. The rats were given DMH at 20 mg/kg body weight (b.w.)/week for 12 weeks and were orally treated with HES (25 mg/kg b.w.) and/or CAP (200 mg/kg b.w.) every other day for 8 weeks. The DMH-administered rats exhibited colon-mucosal hyperplastic polyps, the formation of new glandular units and cancerous epithelial cells. These histological changes were associated with the significant upregulation of colon Ki67 expression and the elevation of the tumor marker, carcinoembryonic antigen (CEA), in the sera. The treatment of the DMH-administered rats with HES and/or CAP prevented these histological cancerous changes concomitantly with the decrease in colon-Ki67 expression and serum-CEA levels. The results also indicated that the treatments with HES and/or CAP showed a significant reduction in the serum levels of lipid peroxides, an elevation in the serum levels of reduced glutathione, and the enhancement of the activities of colon-tissue superoxide dismutase, glutathione reductase and glutathione-S-transferase. Additionally, the results showed an increase in the mRNA expressions of the anti-inflammatory cytokine, IL-4, as well as the proapoptotic protein, p53, in the colon tissues of the DMH-administered rats treated with HES and/or CAP. The TGF-β1 decreased significantly in the DMH-administered rats and this effect was counteracted by the treatments with HES and/or CAP. Based on these findings, it can be suggested that both HES and CAP, singly or in combination, have the potential to exert chemopreventive effects against DMH-induced colon carcinogenesis via the suppression of oxidative stress, the stimulation of the antioxidant defense system, the attenuation of inflammatory effects, the reduction in cell proliferation and the enhancement of apoptosis.

Hesperetin promotes longevity and delays aging via activation of Cisd2 in naturally aged mice

Background

The human CISD2 gene is located within a longevity region mapped on chromosome 4q. In mice, Cisd2 levels decrease during natural aging and genetic studies have shown that a high level of Cisd2 prolongs mouse lifespan and healthspan. Here, we evaluate the feasibility of using a Cisd2 activator as an effective way of delaying aging.

Methods

Hesperetin was identified as a promising Cisd2 activator by herb compound library screening. Hesperetin has no detectable toxicity based on in vitro and in vivo models. Naturally aged mice fed dietary hesperetin were used to investigate the effect of this Cisd2 activator on lifespan prolongation and the amelioration of age-related structural defects and functional decline. Tissue-specific Cisd2 knockout mice were used to study the Cisd2-dependent anti-aging effects of hesperetin. RNA sequencing was used to explore the biological effects of hesperetin on aging.

Results

Three discoveries are pinpointed. Firstly, hesperetin, a promising Cisd2 activator, when orally administered late in life, enhances Cisd2 expression and prolongs healthspan in old mice. Secondly, hesperetin functions mainly in a Cisd2-dependent manner to ameliorate age-related metabolic decline, body composition changes, glucose dysregulation, and organ senescence. Finally, a youthful transcriptome pattern is regained after hesperetin treatment during old age.

Conclusions

Our findings indicate that a Cisd2 activator, hesperetin, represents a promising and broadly effective translational approach to slowing down aging and promoting longevity via the activation of Cisd2.

Investigation of the effect of hesperidin on some reproductive parameters in testicular toxicity induced by Bisphenol A

Bisphenol A (BPA) is one of the chemicals that cause dysfunction and infertility in testicles. Therefore, it is crucial to develop effective treatments against this damage. In this study, the effects of Hesperidin (HESP), a flavonoid in testicular toxicity induced by BPA in rats, on oxidative stress, inflammation, apoptosis, histological damage, spermatogenesis, steroidogenic enzymes and reproductive hormones were investigated. Our study used 52 Sprague Dawley male rats weighing 250-300 g, and four experimental groups were formed. From the experimental groups, 1 ml of olive oil was administered to the control group, HESP at a dose of 50 mg/kg to the HESP group, BPA at a dose of 100 mg/kg to the BPA group, HESP at a dose of 50 mg/kg to the BPA + HESP group and 100 mg/kg BPA was administered intragastrically (ig) for 14 days. We determined that BPA administration causes apoptosis, histological damage, inflammation, oxidative stress and toxic effects on spermatogenesis and steroidogenic enzymes in testicles. We observed that the administration of HESP with BPA attenuated oxidative stress, inflammation and apoptosis resulting in therapeutic effects on both steroidogenic enzymes and spermatogenesis and reproductive hormones (FSH, LH and testosterone). Our findings from this study clearly showed that while HESP treatment alleviates oxidative damage, inflammation and apoptosis in testicles of rats treated with BPA, it has regulatory effects on steroidogenic enzymes, spermatogenesis and serum reproductive hormones.

Hesperidin Functions as an Ergogenic Aid by Increasing Endothelial Function and Decreasing Exercise-Induced Oxidative Stress and Inflammation, Thereby Contributing to Improved Exercise Performance

The regulation of blood flow to peripheral muscles is crucial for proper skeletal muscle functioning and exercise performance. During exercise, increased mitochondrial oxidative phosphorylation leads to increased electron leakage and consequently induces an increase in ROS formation, contributing to DNA, lipid, and protein damage. Moreover, exercise may increase blood- and intramuscular inflammatory factors leading to a deterioration in endurance performance. The aim of this review is to investigate the potential mechanisms through which the polyphenol hesperidin could lead to enhanced exercise performance, namely improved endothelial function, reduced exercise-induced oxidative stress, and inflammation. We selected in vivo RCTs, animal studies, and in vitro studies in which hesperidin, its aglycone form hesperetin, hesperetin-metabolites, or orange juice are supplemented at any dosage and where the parameters related to endothelial function, oxidative stress, and/or inflammation have been measured. The results collected in this review show that hesperidin improves endothelial function (via increased NO availability), inhibits ROS production, decreases production and plasma levels of pro-inflammatory markers, and improves anaerobic exercise outcomes (e.g., power, speed, energy). For elite and recreational athletes, hesperidin could be used as an ergogenic aid to enhance muscle recovery between training sessions, optimize oxygen and nutrient supplies to the muscles, and improve anaerobic performance.

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.

Hesperetin Nanocrystals Improve Mitochondrial Function in a Cell Model of Early Alzheimer Disease

Mitochondrial dysfunction represents a hallmark of both brain aging and age-related neurodegenerative disorders including Alzheimer disease (AD). AD-related mitochondrial dysfunction is characterized by an impaired electron transport chain (ETC), subsequent decreased adenosine triphoshpate (ATP) levels, and elevated generation of reactive oxygen species (ROS). The bioactive citrus flavanone hesperetin (Hst) is known to modulate inflammatory response, to function as an antioxidant, and to provide neuroprotective properties. The efficacy in improving mitochondrial dysfunction of Hst nanocrystals (HstN) with increased bioavailability has not yet been investigated. Human SH-SY5Y cells harboring neuronal amyloid precursor protein (APP₆₉₅) acted as a model for the initial phase of AD. MOCK-transfected cells served as controls. The energetic metabolite ATP was determined using a luciferase-catalyzed bioluminescence assay. The activity of mitochondrial respiration chain complexes was assessed by high-resolution respirometry using a Clarke electrode. Expression levels of mitochondrial respiratory chain complex genes were determined using quantitative real-time polymerase chain reaction (qRT-PCR). The levels of amyloid β-protein (Aβ_1-40) were measured using homogeneous time-resolved fluorescence (HTRF). ROS levels, peroxidase activity, and cytochrome c activity were determined using a fluorescence assay. Compared to pure Hst dissolved in ethanol (HstP), SH-SY5Y-APP₆₉₅ cells incubated with HstN resulted in significantly reduced mitochondrial dysfunction: ATP levels and respiratory chain complex activity significantly increased. Gene expression levels of RCC I, IV, and V were significantly upregulated. In comparison, the effects of HstN on SY5Y-MOCK control cells were relatively small. Pure Hst dissolved in ethanol (HstP) had almost no effect on both cell lines. Neither HstN nor HstP led to significant changes in Aβ_1-40 levels. HstN and HstP were both shown to lower peroxidase activity significantly. Furthermore, HstN significantly reduced cytochrome c activity, whereas HstP had a significant effect on reducing ROS in SH-SY5Y-APP₆₉₅ cells. Thus, it seems that the mechanisms involved may not be linked to altered Aβ production. Nanoflavonoids such as HstN have the potential to prevent mitochondria against dysfunction. Compared to its pure form, HstN showed a greater effect in combatting mitochondrial dysfunction. Further studies should evaluate whether HstN protects against age-related mitochondrial dysfunction and thus may contribute to late-onset AD.

Hesperetin as an inhibitor of the snake venom serine protease from Bothrops jararaca

The majority (90%) of the snakebite envenomation in Brazil accounts for Bothrops from the Viperidae family. Some snake venom serine proteases provoke blood coagulation in ophidian accident victims because of their fibrinolytic activity, one of those proteases from Bothrops jararaca (B. jararaca) has been chosen for this study. Our objectives were to isolate and characterize the target serine protease; isolate, purify, and characterize the orange bagasse flavone (hesperetin, Hst), and investigate the interactions between the targets, enzyme, and hesperetin. The purified serine protease was named BjSP24 because of its molecular mass and proteolytic activity. BjSP24 was folded and characterized using circular dichroism and showed low alpha-helix contents (7.7%). BjSP24 exhibited sequence similarity to other known snake venom serine proteases as measured in the enzyme tryptic peptides' LC-MS/MS run. Hesperetin was obtained within the expected yield and with the predominance of 2S isomer (82%). It acted as a mixed inhibitor for the serine protease (SVSP) from Bothrops jararaca snake venom observed in three different in vitro experiments, fluorescence, kinetics, and SSTD-NMR. It is still to determine if hesperetin might aid-in reverting the on site blood clotting problems just after snakebite accidents.

Hesperetin improves diabetic coronary arterial vasomotor responsiveness by upregulating myocyte voltage‑gated K+ channels

Hesperetin (HSP) is a naturally occurring flavonoid. The present study aimed to investigate the potential vasomotor effects and mechanisms of HSP action on rat coronary arteries (RCAs) injured by diabetes or high glucose concentrations. HSP (100 mg/kg/day) was intragastrically administered to the rats for 8 weeks, which were rendered diabetic with a single intraperitoneal injection of 60 mg/kg streptozotocin (STZ). The vascular tone of RCAs was recorded using a wire myograph. The voltage-dependent K⁺ (Kv) currents were examined using patch clamping. The expression of Kv channels (Kv1.2 and Kv1.5) was examined by western blot analysis and reverse transcription-quantitative PCR (RT-qPCR). Diabetes induced contractile hypersensitivity and vasodilator hyposensitivity in RCAs, both of which were attenuated by the chronic administration of HSP. Patch clamp data revealed that chronic HSP treatment reduced diabetes-induced suppression of Kv currents in the myocytes. Western blot and RT-qPCR analyses revealed that chronic HSP administration increased the expression of Kv1.2, but not Kv1.5, in the RCAs of diabetic rats compared with those from non-diabetic rats. In vitro analysis showed that co-incubation with HSP ameliorated high-glucose-induced suppression of Kv currents and Kv 1.2 protein expression in the myocytes. Taken together, the present study demonstrated that HSP alleviated RCA vasomotor dysfunction as a result of diabetes in rats by upregulating the expression of myocyte Kv channels.

Rescue role of hesperidin in 4-vinylcyclohexene diepoxide-induced toxicity in the brain, ovary and uterus of wistar rats

Background The ovotoxicity of 4-vinylcyclohexene diepoxide (VCD) has been established in several experimental models. Hesperidin (HSD) is a bi-flavonoid found in citrus fruits and has been reported to be a potent antioxidant and anti-inflammatory agent. Here, we have evaluated the rescue role of hesperidin on VCD-induced toxicity in the brain, ovary, and uterus of rats. Methods Six groups of rats containing ten rats in each group were orally given corn oil (control), hesperidin (100 mg/kg), hesperidin (200 mg/kg), VCD (250 mg/kg), VCD [(250 mg/kg)+hesperidin (100 mg/kg)] and VCD [(250 mg/kg)+hesperidin (200 mg/kg)] once a day for 30 days, respectively. Thereafter, we determined the selected biomarkers of oxidative damage, inflammation, endocrine balance, and histology of the reproductive organs. Results The data showed that hesperidin rescued VCD-induced increase in oxidative stress (hydrogen peroxide and malondialdehyde) and inflammatory (nitric oxide) biomarkers. In addition, hesperidin restored the reduction in antioxidant enzymes (catalase, glutathione S-transferase, glutathione peroxidase) activities and glutathione level in the brain, ovary, and uterus of rats (p<0.05). Lastly, hesperidin preserved the histological structure of the ovary and uterus of rats exposed to VCD. Conclusions Overall, the rescue role of hesperidin on VCD-induced toxicity in the brain and reproductive organs of female rats may be due to its antioxidative and anti-inflammatory properties.

Protective Effect of Hesperidin on the Oxidative Stress Induced by an Exhausting Exercise in Intensively Trained Rats

Intensive exercise can lead to oxidative stress, which can be particularly deleterious for lymphoid tissues. Hesperidin has demonstrated its antioxidant activity, but few studies focus on its influence on intensive training. The aim of this study was to assess the impact of hesperidin on the oxidant/antioxidant status of lymphoid tissues after an intensive training program. Wistar rats were trained for five weeks (five days per week), including two exhaustion tests plus three trainings per week. During this period, animals were orally administrated with 200 mg/kg of hesperidin or vehicle (three days per week). The oxidative status was determined before, immediately after and 24 h after an additional exhaustion test. The production of reactive oxygen species (ROS) by peritoneal macrophages, superoxide dismutase (SOD) and catalase activities in spleen, thymus and liver, and hepatic glutathione peroxidase activity (GPx) were assessed. Hesperidin prevented an increase in ROS production induced by the additional exhaustion test. Likewise, hesperidin avoided a decrease in SOD and catalase activities in the thymus and spleen that was found after the additional exhaustion test. The antioxidant effects of hesperidin were associated with a higher performance in the assessed training model. These results suggest that hesperidin, acting as an antioxidant, can prevent oxidative stress induced by exercise and improve exercise performance.

Aluminium phosphide-induced testicular toxicity through oxidative stress in Wistar rats: Ameliorative role of hesperidin

The present study was designed to investigate aluminium phosphide (ALP)-induced testicular toxicity, including its effects on sperm parameters and histological alterations in Wistar rats, and the possible protective role of hesperidin (HSD). Oral administration of ALP at 1.15 mg/kg body weight (1/10 LD50) for 30 days resulted in a significant increase in testicular malondialdehyde, lipid hydroperoxides, and oxidized protein levels. These indicators of oxidative stress were accompanied by decreased activity of the antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase, followed by a drastic reduction in the non-enzymatic antioxidant indices of glutathione and total antioxidant capacity when compared to control. Furthermore, ALP treatment produced a marked reduction in sperm count, motility and viability while increasing abnormal sperm morphology and adverse histopathological changes in testis. Co-administration with HSD significantly ameliorated ALP-induced testicular damage by suppressing oxidative stress indices and enhancing antioxidant status while also improving the sperm parameters and histological alterations in ALP-treated rats. The results of the present study indicated that testicular toxic effects of ALP are due to oxidative imbalance and that HSD could be a potential therapeutic agent against ALP-induced testicular damage.

Hesperidin Prevents Nitric Oxide Deficiency-Induced Cardiovascular Remodeling in Rats via Suppressing TGF-β1 and MMPs Protein Expression

Hesperidin is a major flavonoid isolated from citrus fruits that exhibits several biological activities. This study aims to evaluate the effect of hesperidin on cardiovascular remodeling induced by n-nitro l-arginine methyl ester (l-NAME) in rats. Male Sprague-Dawley rats were treated with l-NAME (40 mg/kg), l-NAME plus hesperidin (15 mg/kg), hesperidin (30 mg/kg), or captopril (2.5 mg/kg) for five weeks (n = 8/group). Hesperidin or captopril significantly prevented the development of hypertension in l-NAME rats. l-NAME-induced cardiac remodeling, i.e., increases in wall thickness, cross-sectional area (CSA), and fibrosis in the left ventricular and vascular remodeling, i.e., increases in wall thickness, CSA, vascular smooth muscle cells, and collagen deposition in the aorta were attenuated by hesperidin or captopril. These were associated with reduced oxidative stress markers, tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta 1 (TGF-β1), and enhancing plasma nitric oxide metabolite (NOx) in l-NAME treated groups. Furthermore, up-regulation of tumor necrosis factor receptor type 1 (TNF-R1) and TGF- β1 protein expression and the overexpression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) was suppressed in l-NAME rats treated with hesperidin or captopril. These data suggested that hesperidin had cardioprotective effects in l-NAME hypertensive rats. The possible mechanism may involve antioxidant and anti-inflammatory effects.

Role of Plant-Derived Flavonoids and Their Mechanism in Attenuation of Alzheimer's and Parkinson's Diseases: An Update of Recent Data

Neurodegeneration is a progressive loss of neuronal cells in certain regions of the brain. Most of the neurodegenerative disorders (NDDs) share the communal characteristic such as damage or reduction of various cell types typically including astrocytes and microglial activity. Several compounds are being trialed to treat NDDs but they possess solitary symptomatic advantages along with copious side effects. The finding of more enthralling and captivating compounds to suspend and standstill the pathology of NDDs will be considered as a hallmark of present times. Phytochemicals possess the potential to alternate the synthetic line of therapy against NDDs. The present review explores the potential efficacy of plant-derived flavonoids against most common NDDs including Alzheimer's disease (AD) and Parkinson's disease (PD). Flavonoids are biologically active phytochemicals which possess potential pharmacological effects, including antiviral, anti-allergic, antiplatelet, anti-inflammatory, anti-tumor, anti-apoptotic and anti-oxidant effects and are able to attenuate the pathology of various NDDs through down-regulating the nitric oxide (NO) production, by reducing the tumor necrosis factor-α (TNF-α), by reducing the excitotoxicity of superoxide as well as acting as tyrosine kinase (TK) and monoamine oxidase (MAO) inhibiting enzyme.

Hesperidin, a citrus flavonoid, protects against l-methionine-induced hyperhomocysteinemia by abrogation of oxidative stress, endothelial dysfunction and neurotoxicity in Wistar rats

CONTEXT

Hesperidin (HSP), a flavanoglycone found in citrus fruits, has antioxidant, anti-inflammatory and neuroprotective properties.

OBJECTIVE

This study evaluates the protective effect of HSP on l-methionine-induced hyperhomocysteinemia (HHcy) in rats.

MATERIALS AND METHODS

Male Wistar rats were randomly divided into seven groups as DMSO, l-methionine, HSP (25, 50 and 100 mg/kg), HSP-per se (100 mg/kg) and donepezil (0.1 mg/kg). HHcy was induced by oral administration of l-methionine (1.7 g/kg) for 32 days. From the 14^th day of study HSP (25, 50 and 100 mg/kg) and donepezil was administered orally to l-methionine-treated rats. Cognitive impairment induced by HHcy was determined using the Morris water maze (MWM) and Y-maze on video tracking system (28^th-32^nd day). Different biomarkers of HHcy in serum and brain and vascular reactivity were evaluated and histopathology (thoracic aorta and brain) was done.

RESULTS

HSP (100 mg/kg) treatment in l-methionine-treated rats exhibited significant (p < 0.001) dose-dependent activity and reduced behavioural deficits, brain acetylcholinesterase (25.99 ± 2.36 versus 10.73 ± 1.26 μmoles/mg), brain lipid peroxidation (15.25 ± 1.65 versus 6.18 ± 0.74 nM/mg), serum homocysteine (Hcy) (22.37 ± 0.30 versus 11.01 ± 1.01 μg/mL) and serum cholesterol (182.7 ± 2.15 versus 101.5 ± 2.76 mg/dL) and increased brain antioxidant levels. HSP significantly (p < 0.001) reduced endothelial dysfunction (ED) by abolishing the effect of l-methionine on acetylcholine-induced endothelial-dependent relaxation and increased serum nitrite and vascular nitric oxide bioavailability along with the restoration of histological aberrations.

CONCLUSION

HSP exerts a protective effect on HHcy by abrogating oxidative stress, ED and neurotoxicity.

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.

Evaluation of the protective effects of hesperetin against cisplatin-induced ototoxicity in a rat animal model

OBJECTIVES

We aimed to investigate the effects of hesperetin as a flavanon both histopathologically and immunohistochemically on cochlear apoptosis in a rat model of cisplatin-induced ototoxicity (CIO). The evaluation of the effects of hesperetin on cisplatin-induced hearing loss was performed using distortion product otoacoustic emission (DPOAE).

METHODS

Twenty-eight wistar albino rats were used in the current study. The rats were randomly divided into four groups with seven rats in each group. Group C was exposed to a single dose of cisplatin (12mg/kg) by intraperitoneal injection. Group CH received intraperitoneally cisplatin (12mg/kg) and hesperetin (20mg/kg). Group H was exposed to hesperetin (20mg/kg) intraperitoneally. The sham group (group S) received normal saline (6cc) intraperitoneally. The measurements of DPOAE and signal-noise ratios (SNR) were performed before the treatment and again on the first and 6 days after administration of the drugs. Rats were sacrificed and cochleae were dissected 10 days after drug administration. The cochlear tissue was assessed in all groups by histopathologic, immunohistochemical and TUNEL assay. In addition, serum oxidative stress markers and antioxidant parameters were analyzed.

RESULTS

There was a significant difference between the basal value and the sixth day at frequencies 8.4, 9.6 and 9.96 for group C. We also found a significant difference between the first and sixth day at frequencies 7.2, 8.4, 9.6 and 9.96. On the 6th day, there were significant differences between C and S groups at all frequencies except 2.4. We showed a significant difference between C and H groups at frequencies 4.8, 6.0, 8.4, 9.6 and 9.96. There was also a significant difference between C and CH groups at frequencies 2.4, and 3.6. We found lower levels of oxidants and higher levels of antioxidants in CH group as compared to C group. C group had a significantly greater number of TUNEL-positive cells than did S, H and CH groups. The number of TUNEL-positive cells in CH group was higher than in S and H groups. There was a significant difference between the positive PCNA cells of CH group compared to S and H groups in spiral ganglion and stria vascularis. In addition, there were no positive PCNA cells in C group.

CONCLUSIONS

Hesperetin may prevent ototoxicity by increased antioxidant enzymes and reduced oxidant parameters and protected against apoptosis resulting from a proliferation of cochlear cells in CIO.

Exploring the Potential Role of Chemopreventive Agent, Hesperetin Conjugated Pegylated Gold Nanoparticles in Diethylnitrosamine-Induced Hepatocellular Carcinoma in Male Wistar Albino Rats

Liver cancer is the fifth most common cancer and is still one of the leading causes of death world wide, due to food additives, alcohol, fungal toxins, air, toxic industrial chemicals, and water pollutants. Chemopreventive drugs play a potential role in liver cancer treatment. Obviously in the production of anticancer drugs, the factors like poor solubility, bioavailability, biocompatibility, limited chemical stability, large amount of dose etc., plays a major role. Against this backdrop, the idea of designing the chemopreventive nature of bio flavanoid hesperetin (HP) drug conjugated with pegylated gold nanoparticles to increasing the solubility, improve bioavailability and enhance the targeting capabilities of the drug during diethylnitrosamine (DEN) induced liver cancer in male wistar albino rats. The dose fixation studies and the toxicity of pure HP and HP conjugated gold nanoparticles (Au-mPEG(5000)-S-HP) were analysed. After concluded the dose fixation and toxicity studies the experimental design were segregated in six groups for the anticancer analysis of DEN induced HCC for 16 weeks. After the experimental period the body weight, relative liver weight, number of nodules and size of nodules, the levels of tumor markers like CEA, AFP and the level of lipid peroxidation, lipid hydroperoxides and the activities of antioxidant enzymes were assessed. The administration of DEN to rats resulted in increased relative liver weight and serum marker enzymes aspartate transaminase, alanine transaminase, alkaline phosphatase, lactate dehydrogenase, and gamma glutamyl transpeptidase. The levels of lipid peroxides elevated (in both serum and tissue) with subsequent decrease in the final body weight and tissue antioxidants like superoxide dismutase, catalase, reduced glutathione, glutathione peroxidise, and glutathione reductase. HP supplementation (20 mg/kg b.wt) significantly attenuated these alterations, thereby showing potent anticancer effect in liver cancer and the HP loaded gold nanoparticels (Au-mPEG(5000)-S-HP) treated animals shows the better treatment than the pure HP due to the solubility of drug, bioavailability and the target drug delivery of the biodegradable polymer. Histological observations were also carried out, which added supports to the chemopreventive action of the pure HP and HP loaded gold nanoparticles (Au-mPEG(5000)-S-HP) against DEN induction during liver cancer progression. These findings suggest that HP loaded gold nanoparticels (Au-mPEG(5000)-S-HP) shows better efficacy than the pure HP against lipid peroxidation, hepatic cell damage and protects the antioxidant system in DEN induced hepatocellular carcinogenesis.

Radioprotective effect of hesperetin against γ-irradiation-induced DNA damage and immune dysfunction in murine splenocytes

This study was conducted to evaluate the preventive effect of hesperetin against radiation-induced DNA damage and immune dysfunction in murine splenocytes. Isolated splenocytes from BALB/c mice were treated with hesperetin (20, 100, and 500 µM), and then irradiated at a dose of 2 and 4 Gy of γ-irradiation. Exposure to ?-radiation resulted in DNA damage and a reduction of cell viability as well as an elevation of the levels of proinflammatory cytokines, intracellular ROS (reactive oxygen species), and NO (nitric oxide). Hesperetin significantly enhanced the cell viability of the splenocytes compared with the irradiated group. In addition, hesperetin was found to be highly effective in preventing DNA damage as identified by comet and DNA ladder assays. Hesperetin also effectively inhibited proinflammatory cytokines, intracellular ROS, and NO in irradiated splenocytes. In conclusion, hesperetin was shown to be radioprotective against irradiation-induced DNA damage and immune dysfunction in murine splenocytes.

A sensitive phosphorescence method based on MPA-capped Mn-doped ZnS quantum dots for the detection of diprophyllin

The mechanism of the phosphorescence quenching process of Mn-doped ZnS QDs by DPP.

Hesperetin attenuates ventilator-induced acute lung injury through inhibition of NF-κB-mediated inflammation

Hesperetin, a major bioflavonoid in sweet oranges and lemons, has been reported to have anti-inflammatory properties. However, the effect of hesperetin on ventilator-induced acute lung injury has not been studied. In present study, we investigated the protective effect of hesperetin on ventilator-induced acute lung injury in rats. Rats were orally administered hesperetin (10, 20, or 40mg/kg) two hour before acute lung injury was induced by mechanical ventilation. Rats were then randomly divided into six groups: the lung protective ventilation group (n=20, LV group), injurious ventilation group (n=20, HV group), vehicle-treated injurious ventilation group (n=20, LV+vehicle group), hesperetin (10mg/kg)-treated acute lung injury group (n=20, HV+Hsp (10mg)), hesperetin (20mg/kg)-treated acute lung injury group (n=20, HV+Hsp (20mg)), and hesperetin (40mg/kg)-treated acute lung injury group (n=20, HV+Hsp (40mg)). The lung tissues and bronchoalveolar lavage fluid were isolated for subsequent measurements. Treatment with hesperetin dramatically improved the histology of lung tissue, and reduced the wet/dry ratio, myeloperoxidase activity, protein concentration, and production of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, and MIP-2 in the bronchoalveolar lavage fluid of rats with ventilator-induced acute lung injury. Additionally, our study indicated that this protective effect of hesperetin results from its ability to increase the expression of peroxisome proliferator-activated receptor (PPAR)-γ and inhibit the activation of the nuclear factor (NF)-κB pathway. These results suggest that hesperetin may be a potential novel therapeutic candidate for protection against ventilator-induced acute lung injury.

Hesperetin Induces the Apoptosis of Gastric Cancer Cells via Activating Mitochondrial Pathway by Increasing Reactive Oxygen Species

BACKGROUND

Hesperetin, has been shown to exert biological activities on various types of human cancers. However, few related studies on gastric cancer are available.

AIM

In this study, we sought to investigate the effect of hesperetin on gastric cancer and clarify its specific mechanism.

MATERIALS AND METHODS

Cell Counting Kit-8, 2',7'-dichlorofluorescin diacetate, JC-1, Hoechst 33258 staining, and western bolt were used to detect cell viability, levels of intracellular reactive oxygen species (ROS), changes in mitochondrial membrane potential (△ψ m), cell apoptosis, and expressions of mitochondrial pathway proteins, respectively. Meanwhile, xenograft tumor models in nude mice were made to evaluate the effect of hesperetin on gastric cancer in vivo.

RESULTS

Compared with the control group, the proliferation of gastric cancer cells in hesperetin groups was significantly inhibited (P < 0.05), and dose- and time-dependent effects were observed. Pretreatment with H2O2 (1 mM) or N-acetyl-L-cysteine (5 mM) enhanced or attenuated the hesperetin-induced inhibition of cell viability (P < 0.05). Percentages of apoptotic cells, levels of intracellular ROS, and △ψ m varied with the dose and treatment time of hesperetin (P < 0.05), and hesperetin caused an increase in the levels of AIF, Apaf-1, Cyt C, caspase-3, caspase-9, and Bax and a decrease in Bcl-2 levels (P < 0.05). Meanwhile, hesperetin significantly inhibited the growth of xenograft tumors (P < 0.05).

CONCLUSION

Our study suggests that hesperetin could inhibit the proliferation and induce the apoptosis of gastric cancer cells via activating the mitochondrial pathway by increasing the ROS.

Evaluation of topical hesperetin matrix film for back-of-the-eye delivery

PURPOSE

The goal of the present study was to develop a poly (ethylene oxide) N10 (PEO N10) based melt-cast matrix system for efficient and prolonged delivery of hesperetin (HT), a promising bioflavonoid, to the posterior segment of the eye through the topical route.

METHODS

HT film was prepared by melt-cast method using PEO N10 and cut into 4mm×2mm segments, each weighing 8mg. This film was evaluated with respect to in vitro release rates and also transmembrane delivery across Spectra/Por® membrane (MWCO: 10,000 Daltons) and isolated rabbit corneas. Ocular tissue concentrations were also determined postapplication of the film in ex vivo and in vivo models.

RESULTS

HT release from the film was determined to be about 95.3% within 2h. In vitro transcorneal flux was observed to be 0.58±0.05μg/min/cm(2) across the isolated rabbit cornea. High levels of HT were detected in the retina-choroid (RC) and vitreous humor (VH) in the ex vivo model following topical application of the film. Significant levels of HT were observed in both anterior and posterior segment ocular tissues 1h post topical application of the 10 and 20%w/w HT films on the rabbit eye. Moreover, HT was detected in the VH and RC even after 6h following topical application of the film in vivo.

CONCLUSION

The results from this study suggest that the melt-cast films can serve as a viable platform for sustained topical delivery of bioflavonoids, and other therapeutic agents, into the back-of-the eye tissues.

Hesperidin as a preventive resistance agent in MCF-7 breast cancer cells line resistance to doxorubicin

OBJECTIVE

To evaluate of hesperidin to overcome resistance of doxorubicin in MCF-7 resistant doxorubicin cells (MCF-7/Dox) in cytotoxicity apoptosis and P-glycoprotein (Pgp) expression in combination with doxorubicin.

METHODS

The cytotoxic properties, 50% inhibition concentration (IC50) and its combination with doxorubicin in MCF-7 cell lines resistant to doxorubicin (MCF-7/Dox) cells were determined using MTT assay. Apoptosis induction was examined by double staining assay using ethidium bromide-acridine orange. Immunocytochemistry assay was performed to determine the level and localization of Pgp.

RESULTS

Single treatment of hesperidin showed cytotoxic activity on MCF-7/Dox cells with IC50 value of 11 µmol/L. Thus, combination treatment from hesperidin and doxorubicin showed addictive and antagonist effect (CI>1.0). Hesperidin did not increase the apoptotic induction, but decreased the Pgp expressions level when combined with doxorubicin in low concentration.

CONCLUSIONS

Hesperidin has cytotoxic effect on MCF-7/Dox cells with IC50 of 11 µmol/L. Hesperidin did not increased the apoptotic induction combined with doxorubicin. Co-chemotherapy application of doxorubicin and hesperidin on MCF-7/Dox cells showed synergism effect through inhibition of Pgp expression.

Hesperidin inhibits inflammatory response induced by Aeromonas hydrophila infection and alters CD4+/CD8+ T cell ratio

Background. Aeromonas hydrophila is an opportunistic bacterial pathogen that is associated with a number of human diseases. Hesperidin (HES) has been reported to exert antioxidant and anti-inflammatory activities. Objectives. The aim of this study was to investigate the potential effect of HES treatment on inflammatory response induced by A. hydrophila infection in murine. Methods. A. hydrophila-infected mice were treated with HES at 250 mg/kg b.wt./week for 4 consecutive weeks. Phagocytosis, reactive oxygen species production, CD4⁺/CD8⁺ T cell ratio, and CD14 expression on intestinal infiltrating monocytes were evaluated. The expression of E-selectin and intercellular adhesion molecule 1 on stimulated HUVECs and RAW macrophage was evaluated. Results. Percentage of CD4⁺ T cells in the intestinal tissues of infected treated mice was highly significantly increased; however, phagocytic index, ROS production, CD8⁺ T cells percentage, and CD14 expression on monocytes were significantly reduced. On the other hand, HES significantly inhibited A-LPS- and A-ECP-induced E-selectin and ICAM-1 expression on HUVECs and ICAM-1 expression on RAW macrophage. Conclusion. Present data indicated that HES has a potential role in the suppression of inflammatory response induced by A. hydrophila toxins through downmodulation of ROS production and CD14 and adhesion molecules expression, as well as increase of CD4⁺/CD8⁺ cell ratio.

Oxidative stress and neurodegenerative disorders

Living cells continually generate reactive oxygen species (ROS) through the respiratory chain during energetic metabolism. ROS at low or moderate concentration can play important physiological roles. However, an excessive amount of ROS under oxidative stress would be extremely deleterious. The central nervous system (CNS) is particularly vulnerable to oxidative stress due to its high oxygen consumption, weakly antioxidative systems and the terminal-differentiation characteristic of neurons. Thus, oxidative stress elicits various neurodegenerative diseases. In addition, chemotherapy could result in severe side effects on the CNS and peripheral nervous system (PNS) of cancer patients, and a growing body of evidence demonstrates the involvement of ROS in drug-induced neurotoxicities as well. Therefore, development of antioxidants as neuroprotective drugs is a potentially beneficial strategy for clinical therapy. In this review, we summarize the source, balance maintenance and physiologic functions of ROS, oxidative stress and its toxic mechanisms underlying a number of neurodegenerative diseases, and the possible involvement of ROS in chemotherapy-induced toxicity to the CNS and PNS. We ultimately assess the value for antioxidants as neuroprotective drugs and provide our comments on the unmet needs.

Flavonoid mixture ameliorates increase in erythrocyte osmotic fragility and malondialdehyde concentration induced by Trypanosoma brucei brucei-infection in Wistar rats

The experiment was performed with the aim of investigating the effect of a flavonoid mixture, Daflon® 500 mg (DF) on the erythrocyte fragility and lipoperoxidative changes, induced by Trypanosoma brucei brucei infection in Wistar rats. Fifty adult male rats randomly divided into five groups of 10 animals each were used. Rats in the control group were administered (1 mL/kg) distilled water only, while the other groups were infected with T. brucei brucei and treated with Daflon® 500 mg and/or Diminazene aceturate. At the end of 5 weeks, EDTA-blood samples and serum samples were collected from the rats, and were used to determine erythrocyte osmotic fragility (EOF) and serum malondialdehyde (MDA) concentration respectively. The results showed that EOF and MDA concentration significantly (P<0.05) increased in the infected untreated group when compared to the treatment groups. Treatment with Daflon® 500 mg and Diminazene aceturate significantly (P<0.05) reduced trypanosome-induced increases in EOF and lipoperoxidative changes, suggesting possible antioxidant properties of Daflon® 500 mg and its therapeutic value in trypanosomosis.

Hesperetin alleviates the inhibitory effects of high glucose on the osteoblastic differentiation of periodontal ligament stem cells

Hesperetin (3',5,7-trihydroxy-4-methoxyflavanone) is a metabolite of hesperidin (hesperetin-7-O-rutinoside), which belongs to the flavanone subgroup and is found mainly in citrus fruits. Hesperetin has been reported to be an effective osteoinductive compound in various in vivo and in vitro models. However, how hesperetin effects osteogenic differentiation is not fully understood. In this study, we investigated the capacity of hesperetin to stimulate the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) and to relieve the anti-osteogenic effect of high glucose. Osteogenesis of PDLSCs was assessed by measurement of alkaline phosphatase (ALP) activity, and evaluation of the mRNA expression of ALP, runt-related gene 2 (Runx2), osterix (OSX), and FRA1 as osteogenic transcription factors, as well as assessment of protein expression of osteopontin (OPN) and collagen type IA (COLIA). When PDLSCs were exposed to a high concentration (30 mM) of glucose, osteogenic activity decreased compared to control cells. Hesperetin significantly increased ALP activity at doses of 1, 10, and 100 µM. Pretreatment of cells with hesperetin alleviated the high-glucose-induced suppression of the osteogenic activity of PDLSCs. Hesperetin scavenged intracellular reactive oxygen species (ROS) produced under high glucose condition. Furthermore, hesperetin increased the activity of the PI3K/Akt and β-catenin pathways. Consistent with this, blockage of Akt or β-catenin diminished the protective effect of hesperetin against high glucose-inhibited osteogenic differentiation. Collectively, our results suggest that hesperetin alleviates the high glucose-mediated suppression of osteogenic differentiation in PDLSCs by regulating ROS levels and the PI3K/Akt and β-catenin signaling pathways.

Hesperetin rescues retinal oxidative stress, neuroinflammation and apoptosis in diabetic rats

The purpose of the study was to evaluate the effects of hesperetin (Hsp) on diabetes-induced retinal oxidative stress, neuroinflammation and apoptosis in rats. The Hsp treatment (100 mg/kg body weight) was carried for twenty four weeks in STZ-induced diabetic rats and evaluated for antioxidant (Superoxide dismutase; SOD, Catalase; CAT and glutathione; GSH) enzymes, inflammatory cytokines (TNF-α, IL-1β), caspase-3, glial fibrillary acidic protein (GFAP) and aquaporin-4(AQP4) expression. Histological changes were evaluated by light and transmission electron microscopic (LM and TEM) studies. Retinal GSH levels and anti-oxidant enzymes (SOD and CAT) activity were significantly decreased in diabetic group as compared to normal group. However, in Hsp-treated rats, retinal GSH levels were restored close to normal levels and positive modulation of anti-oxidant enzyme activity was observed. Diabetic retinae showed significantly increased expression of Pro-inflammatory cytokines (TNF-α and IL-1β) as compared to normal retinae. While Hsp-treated retinae showed significantly lower levels of cytokines as compared to diabetic retinae. Diabetic retinae showed increased caspase-3, GFAP and AQP4 expression. However, Hsp-treated retinae showed inhibitory effect on caspase-3, GFAP and AQP4 expression. LM images showed edematous Müller cell endfeet, and also degenerated photoreceptor layer; however, protective effect of Hsp was seen on Müller cell processes and photoreceptors. TEM study showed increased basement membrane (BM) thickness in diabetic retina, while relatively thin BM was recorded in Hsp-treated retina. It can be postulated that dietary flavanoids, like Hsp, can be effective for the prevention of diabetes induced neurovascular complications such as diabetic retinopathy.

Hesperidin and naringin attenuate hyperglycemia-mediated oxidative stress and proinflammatory cytokine production in high fat fed/streptozotocin-induced type 2 diabetic rats

Abnormal regulation of glucose and impaired carbohydrate utilization that result from a defective or deficient insulin are the key pathogenic events in type 2 diabetes mellitus (T2DM). The present study was hypothesized to investigate the beneficial effects of hesperidin and naringin on hyperglycemia-induced oxidative damage in HFD/STZ-induced diabetic rats. Diabetes was induced by feeding rats with an HFD for 2 weeks followed by an intraperitoneal injection of STZ (35 mg/kg body weight). An oral dose of 50mg/kg hesperidin or naringin was daily given for 4 weeks after diabetes induction. At the end of the experimental period, blood was obtained from jugular vein and livers were rapidly excised and homogenized for biochemical assays. In the diabetic control group, levels of glucose, glycosylated hemoglobin (HbA1c%), MDA, NO, TNF-α and IL-6 were significantly increased, while serum insulin, GSH, vitamin C, and vitamin E levels were decreased. Both hesperidin and naringin administration significantly reversed these alterations. Moreover, supplementation with either compound significantly ameliorated serum and liver MDA, NO and glutathione, and liver antioxidant enzymes. Although detailed studies are required for the evaluation of the exact mechanism of the ameliorative effects of hesperidin and naringin against diabetic complications, these preliminary experimental findings demonstrate that both hesperidin and naringin exhibit antidiabetic effects in a rat model of T2DM by potentiating the antioxidant defense system and suppressing proinflammatory cytokine production.