Protective effects of hyperoside (quercetin-3-o-galactoside) to PC12 cells against cytotoxicity induced by hydrogen peroxide and tert-butyl hydroperoxide

The mechanical effects of chemical stimuli on neurospheres

The formulation of more accurate models to describe tissue mechanics necessitates the availability of tools and instruments that can precisely measure the mechanical response of tissues to physical loads and other stimuli. In this regard, neuroscience has trailed other life sciences owing to the unavailability of representative live tissue models and deficiency of experimentation tools. We previously addressed both challenges by employing a novel instrument called the cantilevered-capillary force apparatus (CCFA) to elucidate the mechanical properties of mouse neurospheres under compressive forces. The neurospheres were derived from murine stem cells, and our study was the first of its kind to investigate the viscoelasticity of living neural tissues in vitro. In the current study, we demonstrate the utility of the CCFA as a broadly applicable tool to evaluate tissue mechanics by quantifying the effect that oxidative stress has on the mechanical properties of neurospheres. We treated mouse neurospheres with non-cytotoxic levels of hydrogen peroxide and subsequently evaluated the storage and loss moduli of the tissues under compression and tension. We observed that the neurospheres exhibit viscoelasticity consistent with neural tissue and show that elastic modulus decreases with increasing size of the neurosphere. Our study yields insights for establishing rheological measurements as biomarkers by laying the groundwork for measurement techniques and showing that the influence of a particular treatment may be misinterpreted if the size dependence is ignored.

Quercetin as one of the most abundant represented biological valuable plant components with remarkable chemoprotective effects - A review

As a consequence of environmental quality changes as well as changes in our population's lifestyle, there is rapidly increasing variability and many so-called lifestyle disorders, allergies, and food intolerances (also known as non-allergic food hypersensitivity). Unhealthy eating practices, an inappropriate food composition with an excessive energy intake, a high intake of saturated fats, simple sugars, and salt, as well as an inadequate intake of fibre, vitamins, and substances with preventive effects (such as antioxidants), are some of the factors causing this detrimental phenomenon. Enhanced consumption of plant foods rich in valuable secondary metabolites such as phenolic acids and flavonoids with the benefit on human health, food research focused on these components, and production of foods with declared higher content of biologically active and prophylactic substances are some ways how to change and improve this situation. A unique class of hydroxylated phenolic compounds with an aromatic ring structure are called flavonoids. One unique subclass of flavonoids is quercetin. This phytochemical naturally takes place in fruits, vegetables, herbs, and other plants. Quercetin and its several derivates are considered to be promising substances with significant antidiabetic, antibacterial, anti-inflammatory, and antioxidant effects, which could also act preventively against cardiovascular disease, cancer, or Alzheimer's disease.

Hypericum perforatum: a comprehensive review on pharmacognosy, preclinical studies, putative molecular mechanism, and clinical studies in neurodegenerative diseases

The herb Hypericum perforatum, also referred to as St. John's wort, has drawn a lot of interest because of its potential therapeutic benefits in treating neurodegenerative illnesses. Due to the absence of effective therapies, illnesses like Alzheimer's and Parkinson's disease pose an increasing worldwide health concern. Because of its wide variety of phytochemicals, especially hyperforin, and hypericin, Hypericum perforatum is well known for its neuroprotective properties. These substances have proven to be able to affect different cellular processes linked to neurodegeneration. They can act as anti-inflammatory, antioxidant, and neurotransmitter system regulators, which may help halt neurodegenerative illnesses' progression. The use of Hypericum perforatum extracts and its contents has shown encouraging results in research on animal models of neurodegenerative disorders. These advantages include higher nerve cell survival, lowered oxidative stress, and higher cognitive performance. Underscoring its versatile potential to combat neurodegeneration, Hypericum perforatum has neuroprotective mechanisms that modulate neuroinflammation and prevent apoptotic pathways. In conclusion, Hypericum perforatum shows tremendous promise as a potential treatment for neurological illnesses due to its wide variety of phytochemicals. To completely comprehend its specific mechanisms of action and turn these discoveries into efficient clinical therapies, additional research is needed. Investigating Hypericum perforatum's function in neurodegenerative disorders may present new opportunities for the advancement of ground-breaking therapeutic strategies.

Phytochemical Analysis, Antioxidant Potential and Antibacterial Activities of Different Anatomical Parts of Hypericum cordifolium Choisy

The genus Hypericum comprises a large number of species. The flower, leaf, stem, and root of the Hypericum species are widely used in traditional medicine in different cultures. Many Hypericum species have been well investigated phytochemically and pharmacologically. However, only a few reports are available on the H. cordifolium native to Nepal. The present study aims to evaluate the phytochemical composition of different extracts, qualitative analysis of methanol extract of the flower and leaf using thin-layer chromatography (TLC), and the antioxidant properties of components by the TLC-DPPH. assay. The phenolic and flavonoid contents were estimated in different extracts of the leaf and stem, and their antioxidant and antibacterial activities were evaluated. In the phytochemical screening, phenolics and flavonoids were present in ethyl acetate, methanol, and 50% aq methanol extracts of both the leaf and stem. In TLC analysis, the methanol extract of flowers showed the presence of 11 compounds and the leaf extract showed the presence of 8 compounds. Both extracts contained chlorogenic acid and mangiferin. Hyperoside and quercetin were present only in the flower extract. In the TLC-DPPH. assay, almost all of the flower extracts and 5 compounds of the leaf extract showed radical scavenging potential. Estimation of phenolics and flavonoids showed that all the leaf extracts showed higher amounts of phenolics and flavonoids than stem extracts. Among leaf extracts, greater amounts of phenolics were detected in 50% aqueous methanol extract (261.25 ± 1.66 GAE/g extract) and greater amounts of flavonoids were detected in methanol extract (232.60 ± 10.52 CE/g extract). Among stem extracts, greater amounts of flavonoids were detected in the methanol extract (155.12 ± 4.30 CE/g extract). In the DPPH radical scavenging assay, the methanol extract of the leaf showed IC50 60.85 ± 2.67 µg/ml and 50% aq. methanol extract of the leaf showed IC50 63.09 ± 2.98 µg/ml. The methanol extract of the stem showed IC50 89.39 ± 3.23 µg/ml, whereas ethyl acetate and 50% aq. methanol extract showed IC50 > 100 µg/ml. In the antibacterial assay, the methanol extract of the leaf showed the inhibition zone of 12-13 mm and the stem extract showed the inhibition zone of 7-11 mm against S. aureus, E. coli, and S. sonnei, whereas both extracts were inactive against S. typhi. The findings of this study support the traditional use of this plant in Nepal for the treatment of diseases associated with bacterial infections. The present study revealed that the underutilized anatomical parts of H. cordifolium could be the source of various bioactive phytochemicals like other Hypericum species.

Regulation of mitophagy and mitochondrial function: Natural compounds as potential therapeutic strategies for Parkinson's disease

Mitochondrial damage is associated with the development of Parkinson's disease (PD), indicating that mitochondrial-targeted treatments could hold promise as disease-modifying approaches for PD. Notably, natural compounds have demonstrated the ability to modulate mitochondrial-related processes. In this review article, we discussed the possible neuroprotective mechanisms of natural compounds against PD in modulating mitophagy and mitochondrial function. A comprehensive literature search on natural compounds related to the treatment of PD by regulating mitophagy and mitochondrial function was conducted from PubMed, Web of Science and Chinese National Knowledge Infrastructure databases from their inception until April 2023. We summarize recent advancements in mitophagy's molecular mechanisms, including upstream and downstream processes, and its relationship with PD-related genes or proteins. Importantly, we highlight how natural compounds can therapeutically regulate various mitochondrial processes through multiple targets and pathways to alleviate oxidative stress, neuroinflammation, Lewy's body aggregation and apoptosis, which are key contributors to PD pathogenesis. Unlike the single-target strategy of modern medicine, natural compounds provide neuroprotection against PD by modulating various mitochondrial-related processes, including ameliorating mitophagy by targeting the PINK1/parkin pathway, the NIX/BNIP3 pathway, and autophagosome formation (i.e., LC3 and p62). Given the prevalence of mitochondrial damage in various neurodegenerative diseases, exploring the exact mechanism of natural compounds on mitophagy and mitochondrial dysfunction could shed light on the development of highly effective disease-modifying or adjuvant therapies targeting PD and other neurodegenerative disorders.

Potential Implications of Hyperoside on Oxidative Stress-Induced Human Diseases: A Comprehensive Review

Hyperoside is a flavonol glycoside mainly found in plants of the genera Hypericum and Crataegus, and also detected in many plant species such as Abelmoschus manihot, Ribes nigrum, Rosa rugosa, Agrostis stolonifera, Apocynum venetum and Nelumbo nucifera. This compound exhibits a multitude of biological functions including anti-inflammatory, antidepressant, antioxidative, vascular protective effects and neuroprotective effects, etc. This review summarizes the quantification, original plant, chemical structure and property, structure-activity relationship, pharmacologic effect, pharmacokinetics, toxicity and clinical application of hyperoside, which will be significant for the exploitation for new drug and full utilization of this compound.

Hyperoside protects against oxidative stress-mediated photoreceptor degeneration: therapeutic potentials for photoreceptor degenerative diseases

BACKGROUND

Photoreceptor degeneration underpinned by oxidative stress-mediated mitochondrial dysfunction and cell death leads to progressive and irreversible vision impairment. Drug treatments that protect against photoreceptor degeneration are currently available in the clinical settings. It has been shown that hyperoside, a flavonol glycoside, protects against neuronal loss in part by suppressing oxidative stress and maintaining the functional integrity of mitochondria. However, whether hyperoside protects against photoreceptor degeneration remains unknown.

METHODS

To address the pharmacological potentials of hyperoside against oxidative stress-mediated photoreceptor degeneration on molecular, cellular, structural and functional levels, multiple in vitro and in vivo methodologies were employed in the current study, including live-cell imaging, optical coherence tomography, electroretinography, histological/immunohistochemical examinations, transmission electron microscopy, RNA-sequencing and real-time qPCR.

RESULTS

The in vitro results demonstrate that hyperoside suppresses oxidative stress-mediated photoreceptor cell death in part by mitigating mitochondrial dysfunction. The in vivo results reveal that hyperoside protects against photooxidative stress-induced photoreceptor morphological, functional and ultrastructural degeneration. Meanwhile, hyperoside treatment offsets the deleterious impact of photooxidative stress on multiple molecular pathways implicated in the pathogenesis of photoreceptor degeneration. Lastly, hyperoside attenuates photoreceptor degeneration-associated microglial inflammatory activation and reactive Müller cell gliosis.

CONCLUSIONS

All things considered, the present study demonstrates for the first time that hyperoside attenuates oxidative stress-induced photoreceptor mitochondrial dysfunction and cell death. The photoreceptor-intrinsic protective effects of hyperoside are corroborated by hyperoside-conferred protection against photooxidative stress-mediated photoreceptor degeneration and perturbation in retinal homeostasis, warranting further evaluation of hyperoside as a photoreceptor protective agent for the treatment of related photoreceptor degenerative diseases.

The effects of short term blue light treatment on promoting nutrition value in Chinese cabbage

Chinese cabbage is a nutrients-rich vegetable with diverse leaf colors. Here, we used widely-targeted metabolomics technology to study the metabolic responses of three Chinese cabbage varieties with representative leaf colors after blue light treatment. The inner leaf color of orange varieties 20S530 and 15S1094 changed from yellow to golden yellow, while no visible color change occurred in the common variety 14S23 after the treatment. A total of 844 metabolites were measured from the leaf samples of these three varieties in a time course study after short term blue light treatment, with kaempferol-4'-O-glucoside, isoquercitrin, hyperin, arbutin, sulforaphane as enriched nutritional metabolites. Orange Chinese cabbage varieties showed additional nutrition enhancement after the treatment. This study is the first to explore the global metabolic responses of Chinese cabbage after blue light treatment, and our findings provided valuable insights on how to effectively use lighting conditions to enhance specific groups of nutrients in vegetables.

Antigenotoxic effect of hyperoside against Mitomycin C and hydrogen peroxide-induced genotoxic damage on human lymphocytes

Hyperoside is a flavonol glycoside isolated from various plant genera such as Hypericum and Crataegus. It has an important place in the human diet and is used medically to relieve pain and ameliorate cardiovascular functions. However, a comprehensive profile of the genotoxic and antigenotoxic effects of hyperoside is not known. The current study aimed to investigate the genotoxic and antigenotoxic effects of hyperoside against genetic damages induced by two genotoxins (MMC and H₂O₂) in human lymphocytes using chromosomal aberrations (CAs), sister chromatid exchanges (SCEs), and micronucleus (MN) assays in human peripheral blood lymphocytes in vitro. Blood lymphocytes were incubated with 7.8-62.5 μg/mL concentrations of hyperoside alone and simultaneously with 0.20 μg/mL Mitomycin C (MMC) or 100 μM Hydrogen peroxide (H₂O₂). Hyperoside did not exhibit genotoxic potential in the CA, SCE, and MN assays. Moreover, it did not cause a decrease in mitotic index (MI) which is an indicator of cytotoxicity. On the other hand, hyperoside significantly decreased CA, SCE, and MN (except for MMC treatment) frequencies induced by MMC and H₂O₂. Hyperoside, increased mitotic index against both mutagenic agents at 24-h treatment when compared to positive control. Our results demonstrate that hyperoside exhibited antigenotoxic effects rather than genotoxic in vitro human lymphocytes. Therefore, hyperoside may be a potential preventive agent in inhibiting chromosomal and oxidative damage induced by genotoxic chemicals.

Engineered production of bioactive polyphenolic O-glycosides

Polyphenolic compounds (such as quercetin and resveratrol) possess potential medicinal values due to their various bioactivities, but poor water solubility hinders their health benefits to humankind. Glycosylation is a well-known post-modification method to biosynthesize natural product glycosides with improved hydrophilicity. Glycosylation has profound effects on decreasing toxicity, increasing bioavailability and stability, together with changing bioactivity of polyphenolic compounds. Therefore, polyphenolic glycosides can be used as food additives, therapeutics, and nutraceuticals. Engineered biosynthesis provides an environmentally friendly and cost-effective approach to generate polyphenolic glycosides through the use of various glycosyltransferases (GTs) and sugar biosynthetic enzymes. GTs transfer the sugar moieties from nucleotide-activated diphosphate sugar (NDP-sugar) donors to sugar acceptors such as polyphenolic compounds. In this review, we systematically review and summarize the representative polyphenolic O-glycosides with various bioactivities and their engineered biosynthesis in microbes with different biotechnological strategies. We also review the major routes towards NDP-sugar formation in microbes, which is significant for producing unusual or novel glycosides. Finally, we discuss the trends in NDP-sugar based glycosylation research to promote the development of prodrugs that positively impact human health and wellness.

Quercetin 3-O-Galactoside Isolated from Limonium tetragonum Inhibits Melanogenesis by Regulating PKA/MITF Signaling and ERK Activation

Quercetin 3-O-galactoside (Q3G) is a common dietary flavanol that has been shown to possess several bioactivities, including anti-melanogenesis. However, how Q3G exerts its anti-melanogenic effect has not been studied. The current study, therefore aimed to investigate the anti-melanogenesis potential of Q3G and elucidate the underlying action mechanism in α-melanocyte-stimulating hormone (α-MSH)-induced hyperpigmentation model of B16F10 murine melanoma cells. Results showed that α-MSH stimulation significantly increased tyrosinase (TYR) and melanin production, which were significantly downregulated by Q3G treatment. The treatment with Q3G suppressed the transcriptional and protein expressions of melanogenesis-related enzymes TYR, tyrosinase related protein-1 (TRP-1), and TRP-2, along with the melanogenic transcription factor microphthalmia-associated transcription factor (MITF) in B16F10 cells. It was shown that Q3G downregulated MITF expression and suppressed its transcriptional activity by inhibiting the cAMP-dependent protein kinase A (PKA)-mediated activation of CREB and GSK3β. In addition, MAPK-regulated MITF activation signaling was also involved in the inhibition of melanin production by Q3G. The results suggest that the anti-melanogenic properties of Q3G rationalize further studies in vivo to confirm its action mechanism and consequent utilization as a cosmetic ingredient against hyperpigmentation.

Effect of Common Cooking and Drying Methods on Phytochemical and Antioxidant Properties of Corchorus olitorius Identified Using Liquid Chromatography-Mass Spectrometry (LC-MS)

In this study, Corchorus olitorius leaves were subjected to different thermal treatments (blanching, boiling, drying, frying, and steaming) and analyzed, total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity. Furthermore, Fourier transform infrared spectroscopy (FTIR) was used to identify functional groups, while metabolites were identified with LC-MC. The TPC and antioxidant activity of C. olitorius were significantly (p < 0.05) increased by cooking and drying. The steam-cooked sample had the highest TPC (18.89 mg GAE/g) and TFC (78.42 mg QE/g). With ABTS, FRAP, and DPPH assays, the steam-cooked sample exhibited the highest antioxidant activity of 119.58, 167.31, and 122.23 µM TE/g, respectively. LC-MS identified forty-two (42) metabolites in C. olitorius that included phenolic acid derivatives, flavonoid derivatives, and amino acid derivatives. Overall, steaming appears to be the best cooking method, with respect to the retention of phytochemical compounds and antioxidant activity.

Arbutus unedo: Innovative Source of Antioxidant, Anti-Inflammatory and Anti-Tyrosinase Phenolics for Novel Cosmeceuticals

Phenolic compounds are valuable cosmetic ingredients. They display skin protective potential and play an important role in preserving cosmetic formulations due to their ability to neutralize free radicals. Considering this fact, the current study aims to obtain a phenolic-enriched fraction from Arbutus unedo for topical application in cosmeceutical products. The chemical composition and the antioxidant, anti-inflammatory, and anti-tyrosinase activities of different extracts from the plant were investigated and compared. Samples were obtained by maceration, reflux, and ultrasound using water and ethanol. The findings indicated that the extraction methods impacted the phytochemical composition of the extracts. The high-performance liquid chromatography with diode-array detection (HPLC–DAD) analysis showed a wide range of phenolic compounds, comprising phenolic acids and flavonoids. Among the extracts, the water reflux had significant levels of both total polyphenols, flavonoids, and tannins and possessed the most important content on hyperoside. It displayed the most significant antioxidant activities with high antiradical and reducing power, as well as strong total antioxidant activity. It possesses a promising whitening effect with high anti-tyrosinase activities. Furthermore, it shows no cytotoxicity and moderate anti-inflammatory activity. Finally, due to its high yield efficiency and activities, water reflux was selected to formulate a cosmeceutical oil-in-water nanoemulsion that displayed optimal pH and stability.

Salicornia ramosissima: A New Green Cosmetic Ingredient with Promising Skin Effects

This study aims to validate a new cosmetic ingredient from Salicornia ramosissima S J. Woods through in vitro and ex vivo assays. The halophyte extracts were obtained by subcritical water extraction (SWE) at different temperatures (110, 120, 140, 160 and 180 °C). The antioxidant/radical scavenging activities and the phenolic profile were screened for all extracts. The optimal extract was assessed in keratinocytes and fibroblasts, while permeation assays were performed in Franz cells. The inhibitory activity of hyaluronidase and elastase was also evaluated. The sample extracted at 180 °C presented the highest phenolic content (1739.28 mg/100 g of dry weight (dw)). Despite not being efficient in the sequestration of ABTS^•+, this extract scavenged the DPPH^• (IC₅₀ = 824.57 µg/mL). The scavenging capacity of superoxide (O₂^•-) and hypochlorous acid (HOCl) was also considerable (respectively, IC₅₀ = 158.87 µg/mL and IC₅₀ = 5.80 µg/mL). The cell viability assays confirmed the absence of negative effects on keratinocytes, while the fibroblasts' viability slightly decreased. The ex vivo permeation of rutin, quercetin and syringic acid after 24 h was, respectively, 11, 20 and 11%. Additionally, the extract showed a good elastase and hyaluronidase inhibitory activity. The results obtained support the S. ramosissima bioactivity as a cosmetic ingredient.

Crosstalk between xanthine oxidase (XO) inhibiting and cancer chemotherapeutic properties of comestible flavonoids- a comprehensive update

Gout is an inflammatory disease caused by metabolic disorder or genetic inheritance. People throughout the world are strongly dependent on ethnomedicine for the treatment of gout and some receive satisfactory curative treatment. The natural remedies as well as established drugs derived from natural sources or synthetically made exert their action by mechanisms that are closely associated with anticancer treatment mechanisms regarding inhibition of xanthine oxidase, feedback inhibition of de novo purine synthesis, depolymerization and disappearance of microtubule, inhibition of NF-ĸB activation, induction of TRAIL, promotion of apoptosis, and caspase activation and proteasome inhibition. Some anti-gout and anticancer novel compounds interact with same receptors for their action, e.g., colchicine and colchicine analogues. Dietary flavonoids, i.e., chrysin, kaempferol, quercetin, fisetin, pelargonidin, apigenin, luteolin, myricetin, isorhamnetin, phloretinetc etc. have comparable IC₅₀ values with established anti-gout drug and effective against both cancer and gout. Moreover, a noticeable number of newer anticancer compounds have already been isolated from plants that have been using by local traditional healers and herbal practitioners to treat gout. Therefore, the anti-gout plants might have greater potentiality to become selective candidates for screening of newer anticancer leads.

Hyperoside ameliorates TNF‑α‑induced inflammation, ECM degradation and ER stress‑mediated apoptosis via the SIRT1/NF‑κB and Nrf2/ARE signaling pathways in vitro

Intervertebral disc degeneration (IDD) is the main pathogenesis of numerous cases of chronic neck and back pain, and has become the leading cause of spinal-related disability worldwide. Hyperoside is an active flavonoid glycoside that exhibits anti-inflammation, anti-oxidation and anti-apoptosis effects. The purpose of the present study was to investigate the effect of hyperoside on tumor necrosis factor (TNF)-α-induced IDD progression in human nucleus pulposus cells (NPCs) and its potential mechanism. The activity and apoptosis of NPCs were detected by Cell Counting Kit-8 and flow cytometry analyses, respectively. The expression of interleukin (IL)-6 and IL-1β was detected with ELISA kits. Western blotting was used to detect the expression levels of proteins. The results showed that hyperoside effectively alleviated TNF-α-induced NPC apoptosis, and hyperoside treatment inhibited the upregulation of inducible nitric oxide synthase, cyclooxygenase-2, IL-1β and IL-6 in TNF-α-stimulated NPCs. Compared with the findings in the TNF-α group, the intervention of hyperoside attenuated the upregulated expression of aggrecan and collagen II, and downregulated the expressions of matrix metalloproteinase (MMP) 3, MMP13 and a disintegrin and metalloproteinase with thrombospondin motifs 5. In addition, hyperoside upregulated sirtuin-1 (SIRT1) and nuclear factor E2-related factor 2 (Nrf2) protein expression, and inhibition of SIRT1 or Nrf2 signaling reversed the protective effect of hyperoside on TNF-α-induced NPCs. In summary, hyperoside ameliorated TNF-α-induced inflammation, extracellular matrix degradation, and endoplasmic reticulum stress-mediated apoptosis, which may be associated with the regulation of the SIRT1/NF-κB and Nrf2/antioxidant responsive element signaling pathways by hyperoside.

Hyperoside: A review on its sources, biological activities, and molecular mechanisms

Hyperoside is a natural flavonol glycoside in various plants, such as Crataegus pinnatifida Bge, Forsythia suspensa, and Cuscuta chinensis Lam. Medical research has found that hyperoside possesses a broad spectrum of biological activities, including anticancer, anti-inflammatory, antibacterial, antiviral, antidepressant, and organ protective effects. These pharmacological properties lay the foundation for its use in treating multiple diseases, such as sepsis, arthritis, colitis, diabetic nephropathy, myocardial ischemia-reperfusion, pulmonary fibrosis, and cancers. Hyperoside is obtained from the plants and chemical synthesis. This study aims to provide a comprehensive overview of hyperoside on its sources and biological activities to provide insights into its therapeutic potential, and to provide a basis for high-quality studies to determine the clinical efficacy of this compound.

Development of new and validated HPTLC methods for the qualitative and quantitative analysis of hyperforin, hypericin and hyperoside contents in Hypericum species

PURPOSE

Hypericum perforatum L. (St. John's wort) is a medicinally important member of Hypericaceae. Many pharmacological activities have been mostly attributed to its hyperforin, hypericin and/or hyperoside contents. Therefore, qualitative and quantitative determinations of these ingredients are essential to justify the beneficial effects of St. John's wort on health. In the European Pharmacopoeia, the TLC and HPLC methods were given for this purpose. High performance thin layer chromatography (HPTLC) has recently become increasingly used as a suitable technique for analysing herbal drugs. This study aims to develop new and validated HPTLC methods to analyse these active components in different Hypericum spp. to find other suitable species to replace the official plant.

METHODS

Three different mobile phases were developed: n-hexane-ethyl acetate (8:2) for hyperforin analysis, toluene-chloroform-ethyl acetate-formic acid (8:5:3.5:0.6) for hypericin analysis and ethyl acetate-formic acid-acetic acid-water (15:2:2:1) for hyperoside analysis. These newly developed and validated HPTLC systems were further applied to determine their concentrations in different Hypericum species.

RESULTS

Hyperforin concentration was found between 6.40 to 26.40 mg/g only in H. triquetrifolium, H. scabrum and two H. perforatum samples; hypericin was detected between 0.81 and 1.41 mg/g only in H. bithynicum, H. perfoliatum, H. triquetrifolium and two H. perforatum samples; and hyperoside was identified in all tested specimens ranging from 1.01 to 9.73 mg/g. The new HPTLC methods developed and validated in the present study may ensure reliable results for the qualification and quantification of hyperforin, hypericin and hyperoside contents in Hypericum species.

Hyperoside exerts osteoprotective effect on dexamethasone-induced osteoblasts by targeting NADPH Oxidase 4 (NOX4) to inhibit the reactive oxygen species (ROS) accumulation and activate c-Jun N-terminal kinase (JNK) pathway

Hyperoside (Hyp) is a flavonoid active compound deriving from Chinese herbal medicines. Increasing studies have implicated that Hyp may serve as a predominant promoting factor in osteoblast differentiation. This paper investigates whether Hyp could relieve glucocorticoid-induced osteonecrosis of the femoral head (GONFH) via promoting osteoblast survival and differentiation as well as to uncover its potential mechanism. GONFH cell model was induced by treating MC3T3-E1 cells with dexamethasone (DEX). The viability, apoptosis, and osteogenic differentiation of DEX-induced cells with the presence or absence of Hyp were assessed by CCK-8, Tunel, ALP assay, and ARS staining, respectively. The NADPH Oxidase 4 (NOX4) overexpression was performed by transfection with overexpression vector. Besides, western blot was used to determine the levels of apoptosis-, osteogenic differentiation-, and c-Jun N-terminal kinase (JNK) signaling-related proteins. It was noticed that Hyp caused no significant effects on the viability of MC3T3-E1 cells without any treatment but significantly enhanced the viability of DEX-induced cells. Besides, Hyp inhibited the apoptosis in DEX-induced cells but enhanced ALP activity and calcium nodule formation. Additionally, Hyp declined NOX4 expression in DEX-induced cells. However, NOX4 overexpression partially reversed the impacts of Hyp on DEX-exposed MC3T3-E1 cells. Finally, Hyp suppressed the activation of ROS/JNK pathway in DEX-induced cells, which was then counteracted by NOX4 overexpression. In conclusion, Hyp could promote the survival and differentiation of DEX-induced osteoblasts by targeting NOX4 to inhibit the ROS/JNK pathway. These results provide evidence for the application of Hyp in treating GONFH.

Euphorbia characias: Phytochemistry and Biological Activities

The aim of this review is to summarize all the compounds identified and characterized from Euphorbia characias, along with the biological activities reported for this plant. Euphorbia is one of the greatest genera in the spurge family of Euphorbiaceae and includes different kinds of plants characterized by the presence of milky latex. Among them, the species Euphorbia characias L. is an evergreen perennial shrub widely distributed in Mediterranean countries. E. characias latex and extracts from different parts of the plant have been extensively studied, leading to the identification of several chemical components such as terpenoids, sterol hydrocarbons, saturated and unsaturated fatty acids, cerebrosides and phenolic and carboxylic acids. The biological properties range between antioxidant activities, antimicrobial, antiviral and pesticidal activities, wound-healing properties, anti-aging and hypoglycemic properties and inhibitory activities toward target enzymes related to different diseases, such as cholinesterases and xanthine oxidase. The information available in this review allows us to consider the plant E. characias as a potential source of compounds for biomedical research.

Neuropharmacological Effects of Quercetin: A Literature-Based Review

Quercetin (QUR) is a natural bioactive flavonoid that has been lately very studied for its beneficial properties in many pathologies. Its neuroprotective effects have been demonstrated in many in vitro studies, as well as in vivo animal experiments and human trials. QUR protects the organism against neurotoxic chemicals and also can prevent the evolution and development of neuronal injury and neurodegeneration. The present work aimed to summarize the literature about the neuroprotective effect of QUR using known database sources. Besides, this review focuses on the assessment of the potential utilization of QUR as a complementary or alternative medicine for preventing and treating neurodegenerative diseases. An up-to-date search was conducted in PubMed, Science Direct and Google Scholar for published work dealing with the neuroprotective effects of QUR against neurotoxic chemicals or in neuronal injury, and in the treatment of neurodegenerative diseases. Findings suggest that QUR possess neuropharmacological protective effects in neurodegenerative brain disorders such as Alzheimer’s disease, Amyloid β peptide, Parkinson’s disease, Huntington's disease, multiple sclerosis, and amyotrophic lateral sclerosis. In summary, this review emphasizes the neuroprotective effects of QUR and its advantages in being used in complementary medicine for the prevention and treatment o of different neurodegenerative diseases.

Protective Effect of n-Butanol Extract from Viola yedoensis on Immunological Liver Injury

Viola yedoensis Makino was used to treat inflammation, viral hepatitis, acute pyogenic infection, and ulcerative carbuncles. However, the protective effect on immunological liver injury (ILI) of V. yedoensis had been rarely reported. This study aimed to explore the protective effect of n-butanol extract (BE) from V. yedoensis on ILI in vitro and in vivo. In vitro, the BE significantly inhibited the secretions of Hepatitis B surface antigen (HBsAg) and Hepatitis B e antigen (HBeAg) in the HepG2.2.15 cells and the replication of HBV DNA. The research data in vivo revealed that the BE reduced the levels of alanine transaminase (ALT), aspartate transaminase (AST), and methane dicarboxylic aldehyde (MDA) in liver tissues of the ConA-induced mice, while increased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and the effective contents of tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and the BE could ameliorate liver histological lesions. These results motivated a further investigation into the chemical constituents of BE. Four coumarins (esculetin, prionanthoside, cichoriin, and esculin) and one flavonoid (quercetin-3-O-galactoside) were isolated from the BE by silica gel column chromatography and recrystallization, of which structures were eventually confirmed by ¹ H-NMR, ¹³ C-NMR, and MS.

Protective Effects and Mechanism of Hyperoside in PC12 Cells Against Oxidative Stress Injury Induced by Hydrogen Peroxide

As the aging phenomenon continues to increase, the incidence of neurodegenerative diseases continues to increase annually. As one of the significant contributive factors of neurodegenerative diseases, oxidative stress damage has received extensive attention in recent years. Oxidative stress plays an important role in neuronal damage through various apoptotic mechanisms related to neurodegenerative diseases. The use of natural antioxidants to combat oxidative stress may be a useful approach in delaying disease progression. In this study, we explored the neuroprotective effect of hyperoside on rat pheochromoma (PC12) cells. Specifically, the antioxidant effect and mechanism of hyperoside in hydrogen peroxide (H2O2)-induced cellular cytotoxicity were investigated. Our results showed that hyperoside could significantly increase the survival rate of rat PC12 cells when exposed to H2O2. In addition, hyperoside regulated the expression of genes and proteins in the corresponding pathways by up-regulating the phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt), and light chain 3β (LC3B) pathways and down-regulating the nuclear factor-ᴋ-gene binding (NF-κB), Bcl2-associated X (Bax), cysteinyl aspartate specific proteinase 3 (Caspase 3), and P62 pathways, thereby inhibiting cell apoptosis. Therefore, hyperoside can effectively inhibit H2O2-induced oxidative stress damage by regulating inflammation, autophagy, and apoptosis-related pathways.

leaf extract protects against H2O2-induced oxidative stress by increasing autophagy in PC12 cells

The effect of Apocynum venetum leaf extract (AVLE) on the nervous system has been widely studied, but its effect on injured neurons is not fully understood. In the present study, the protective effect of AVLE on injured neurons was determined. H2O2 was used to induce oxidative stress in PC12 cells and cell viability assays were used to determine the optimum concentration range of AVLE and its protective effects against oxidative stress. A live-dead assay was performed to confirm the effects of AVLE on oxidative stress. Subsequently, expression of apoptotic proteins including Bax and cleaved-caspase-3 were evaluated to determine whether AVLE affected apoptosis, and reactive oxygen species (ROS) levels were detected to determine the role of AVLE in H2O2 exposure. Furthermore, expression of autophagic proteins including LC3-II and p62 were detected to evaluate the effects of AVLE on autophagic activity, and cells were treated with 3-methyladenine (3-MA), an autophagic inhibitor, to identify the underlying protective mechanism of AVLE. The results showed that the optimum conditions to induce oxidative stress were treatment with 40 µM H2O2 for 2 h, and the suitable range of AVLE concentrations was shown to be 1-100 µg/ml. AVLE improved cell viability in PC12 cells following treatment with H2O2. AVLE reduced the expression of Bax and cleaved-caspase-3, and decreased ROS production. Furthermore, AVLE upregulated LC3-II expression and downregulated p62 expression, whereas treatment with 3-MA increased the levels of ROS and apoptotic proteins. These results suggest that AVLE may protect injured neurons against oxidative stress-induced apoptosis, and this effect may be associated with the reduction of ROS by increasing autophagy.

Evaluation of Garlic Landraces from Foggia Province (Puglia Region; Italy)

Interest in local landraces has unfortunately decreased over, the last decades, in which they have been continuously subjected to a high genetic erosion in favour of new modern varieties. Within the Puglia region (S-E Italy), Foggia province was found to be the richest in vegetable landraces. In the present study, six garlic landraces collected from this area have been assessed for their chemical composition (minerals, organic acids, free sugars, volatile, and phenolic compounds) along with their main morpho-biometrical traits. A commercial genotype was also considered as a reference standard. The landraces show a large variability, but in general high morphological standards, high levels of cations and phenols, and low levels of volatile-(S)-compounds in comparison with the commercial genotype and the literature values. 'Aglio di Peschici' and 'Aglio Rosso di Monteleone di Puglia' are very rich in minerals and phenols (mainly ferulic acid and iso-rhamnetin). This increase in knowledge on the chemical properties of these garlic landraces could represent a tool for encouraging the consumption of a food product. At the same time, the consumption of these landraces would stimulate their cultivation and could highly contribute to protection against the risk of erosion of agro-biodiversity by their in situ/on-farm conservation.

Phenolic Profiles of Hardy Kiwifruits and Their Neuroprotective Effects on PC-12 and SH-SY5Y Cells against Oxidative Stress

Hardy kiwifruits (Actinidia arguta Planch.) have high amounts of antioxidants, including ascorbic acid (vitamin C) and phenolics. The anti-cholinesterase activity and neuroprotective effects of three different cultivars of hardy kiwifruits, cv. Mansu (A. arguta × A. deliciosa), cv. Haeyeon (A. arguta), and cv. Chiak (A. arguta), on PC-12 and SH-SY5Y cells were evaluated. Extraction of phenolics and vitamin C was carried out using 80% (v/v) aqueous ethanol and metaphosphoric acid assisted with homogenization, respectively. Hardy kiwifruit of cv. Mansu showed higher total phenolic, total flavonoid, and vitamin C contents and antioxidant capacity compared to the other tw°Cultivars of hardy kiwifruits, cv. Haeyeon and cv. Chiak. Analysis of high-performance liquid chromatography results revealed the presence of procyanidin B2, (?)-epicatechin, neochlorogenic acid, cryptochlorogenic acid, rutin, hyperoside, isoquercitrin, and astragalin in hardy kiwifruits. The three cultivars of hardy kiwifruits had a wide range of vitamin C content of 55.2?130.0 mg/100 g fresh weight. All three cultivars of hardy kiwifruits had protective effects on neuronal PC-12 and SHSY5Y cells exposed to hydrogen peroxide by increasing cell viability and reducing intracellular oxidative stress. Furthermore, the hardy kiwifruits inhibited acetylcholinesterase and butyrylcholinesterase. Collectively, these results suggest that hardy kiwifruits rich in antioxidants like phenolics and vitamin C have good potential as functional materials in neuroprotective applications.

Antibacterial activities of the extracts, fractions and isolated compounds from Canarium patentinervium Miq. against bacterial clinical isolates

Background

Canarium patentinervium leaves are used by the local indigenous people of Malaysia for wound healing. The current study is undertaken to screen the comprehensive antibacterial activity of the leaves and barks extracts, fractions and isolated compounds from this plant. Bioassay guided fractionation was also undertaken to deeply evaluate the antibacterial activity of the water fraction of the leaves extract. This is to provide preliminary scientific evidence to the ethnopharmacology usage of this plant by investigating antibacterial properties of the plant and its isolated constituents.

Methods

Bio-assay guided fractionation and subsequent isolation of compounds using open column chromatography. The antibacterial activity against gram positive and gram negative ATCC strain and resistant clinical strains were evaluated using microtiter broth dilution method to determine minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill assay. The chemical structure of the isolated compounds from the water fraction of the ethanol extract of leaves was elucidated using Nuclear Magnetic Resonance (NMR).

Results

The ethanol extract of the leaves and barks showed antimicrobial activity against all four ATCC and eight clinical isolates. The ethanol extract of the leaves and the corresponding water fraction had good activity against MRSA S. aureus. (MIC: 250 μg/ml) and had bactericidal effect on eight of the clinical strains (MSSA,MRSA, oxacillin-resistant CONS, oxacillin-sensitive CONS, Enterococcus faecalis, Klebsiela species, Kleb pneumoniae ESBL and Candida parapsilosis). Further phytochemical investigation of the water fraction of the crude ethanol extract of leaves afforded compound 7 (hyperin) and compound 8 (cynaroside) that had bactericidal activity against tested bacterial species (MIC 50 μg/ml and 100 μg/ml). The two compounds were isolated from this genus for the first time.

Conclusions

These results may provide a rational support for the traditional use of Canarium patentinervium Miq. in infections and wound healing, since the antimicrobial compounds isolated were also present in the leaves extract.

Suppression of 6-Hydroxydopamine-Induced Oxidative Stress by Hyperoside Via Activation of Nrf2/HO-1 Signaling in Dopaminergic Neurons

In our ongoing research to discover natural products with neuroprotective effects, hyperoside (quercetin 3-O-galactoside) was isolated from Acer tegmentosum, which has been used in Korean traditional medicine to treat liver-related disorders. Here, we demonstrated that hyperoside protects cultured dopaminergic neurons from death via reactive oxygen species (ROS)-dependent mechanisms, although other relevant mechanisms of hyperoside activity remain largely uncharacterized. For the first time, we investigated the neuroprotective effects of hyperoside on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in neurons, and the possible underlying mechanisms. Hyperoside significantly ameliorated the loss of neuronal cell viability, lactate dehydrogenase release, excessive ROS accumulation and mitochondrial membrane potential dysfunction associated with 6-OHDA-induced neurotoxicity. Furthermore, hyperoside treatment activated the nuclear erythroid 2-related factor 2 (Nrf2), an upstream molecule of heme oxygenase-1 (HO-1). Hyperoside also induced the expression of HO-1, an antioxidant response gene. Remarkably, we found that the neuroprotective effects of hyperoside were weakened by an Nrf2 small interfering RNA, which blocked the ability of hyperoside to inhibit neuronal death, indicating the vital role of HO-1. Overall, we show that hyperoside, via the induction of Nrf2-dependent HO-1 activation, suppresses neuronal death caused by 6-OHDA-induced oxidative stress. Moreover, Nrf2-dependent HO-1 signaling activation represents a potential preventive and therapeutic target in Parkinson's disease management.

Oxidative stress differentially induces tau dissociation from neuronal microtubules in neurites of neurons cultured from different regions of the embryonic Gallus domesticus brain

Abnormal phosphorylation of microtubule-associated proteins such as tau has been shown to play a role in neurodegenerative disorders. It is hypothesized that oxidative stress-induced aggregates of hyperphosphorylated tau could lead to the microtubule network degradation commonly associated with neurodegeneration. We investigated whether oxidative stress induced tau hyperphosphorylation and focused on neurite degradation using cultured neurons isolated from the embryonic chick brain as a model system. Cells were isolated from the cerebrum, cerebellum, and tectum of 14-day-old chicks, grown separately in culture, and treated with tert-Butyl hydroperoxide (to simulate oxidative stress) for 48 hr. Relative expression and localization of tau or phospho-tau and β-tubulin III in neurites were determined using quantitative immunocytochemistry and confocal microscopy. In untreated cells, tau was tightly colocalized with β-tubulin III. Increasing levels of oxidative stress induced an increase in overall tau expression in neurites of cerebral and tectal but not the cerebellar neurons, coupled with a decrease in phospho-tau expression in tectal but not the cerebral or cerebellar neurons. In addition, oxidative stress induced the degeneration of the distal ends of the neurites and redistribution of phospho-tau toward the neuronal soma in the cerebral but not the tectal and cerebellar neurons. These results suggest that oxidative stress induces changes in tau protein that precede cytoskeletal degradation and neurite retraction. Additionally, there is a differential susceptibility of neuronal subpopulations to oxidative stress, which may offer potential avenues for investigation of the cellular mechanisms underlying the differential manifestations of neurodegenerative disorders in different regions of the brain.

Investigation of quercetin and hyperoside as senolytics in adult human endothelial cells

Quercetin has been reported to act as a senolytic by selectively removing senescent endothelial cells, and thus it would seem quercetin could revolutionize the field of gerontology. However, given quercetin's narrow therapeutic index reported in work done with human umbilical vein endothelial cells (HUVECs), we hypothesized that quercetin is not innocuous for non-senescent adult human vascular endothelial cells at concentrations that have been reported to be safe for proliferating HUVECs. Furthermore, we investigated quercetin 3-D-galactoside (Q3G; hyperoside), an inactive quercetin derivative that needs to be cleaved by beta-galactosidase overexpressed in senescent cells to release quercetin, as a potential safer senolytic. We compared the effectiveness of quercetin and Q3G in primary human coronary artery endothelial cells (HCAEC), which are adult microvascular cells. We found that quercetin caused cell death in non-senescent endothelial cells at a concentration that has been reported to selectively remove senescent cells, and that Q3G was not cytotoxic to either young or senescent cells. Thus, in primary adult human endothelial cells, quercetin and Q3G are not senolytics. Earlier work reporting positive results was done with HUVECs, and given their origin and the disparate findings from the current study, these may not be the best cells for evaluating potential senolytics in clinically relevant endothelial cells.

Recent advances in discovery and development of natural products as source for anti-Parkinson's disease lead compounds

Parkinson's disease (PD) is a common chronic degenerative disease of the central nervous system. Although the cause remains unknown, several pathological processes and central factors such as oxidative stress, mitochondrial injury, inflammatory reactions, abnormal deposition of α-synuclein, and cell apoptosis have been reported. Currently, anti-PD drugs are classified into two major groups: drugs that affect dopaminergic neurons and anti-cholinergic drugs. Unfortunately, the existing conventional strategies against PD are with numerous side effects, and cannot fundamentally improve the degenerative process of dopaminergic neurons. Therefore, novel therapeutic approaches which have a novel structure, high efficiency, and fewer side effects are needed. For many years, natural products have provided an efficient resource for the discovery of potential therapeutic agents. Among them, many natural products possess anti-PD properties as a result of not only their wellrecognized anti-oxidative and anti-inflammatory activities but also their inhibitory roles regarding protein misfolding and the regulatory effects of PD related pathways. Indeed, with the steady improvement in the technologies for the isolation and purification of natural products and the in-depth studies on the pathogenic mechanisms of PD, many monomer components of natural products that have anti-PD effects have been gradually discovered. In this article, we reviewed the research status of 37 natural products that have been discovered to have significant anti-PD effects as well as their mode of action. Overall, this review may guide the design of novel therapeutic drugs in PD.

Electrochemical luminescence determination of hyperin using a sol-gel@graphene luminescent composite film modified electrode for solid phase microextraction

In this paper, a novel electrochemiluminescence (ECL) sensor of sol-gel@graphene luminescent composite film modified electrode for hyperin determination was prepared using graphene (G) as solid-phase microextraction (SPME) material, based on selective preconcentration of target onto an electrode and followed by luminol ECL detection. Hyperin was firstly extracted from aqueous solution through the modified GCE. Hydrogel, electrogenerated chemiluminescence reagents, pH of working solution, extraction time and temperature and scan rate were discussed. Under the optimum conditions, the change of ECL intensity was in proportion to the concentration of hyperin in the range of 0.02-0.24μg/mL with a detection limit of 0.01μg/mL. This method showed good performance in stability, reproducibility and precision for the determination of hyperin.

Evaluation of the cytotoxic activity of Hypericum spp. on human glioblastoma A1235 and breast cancer MDA MB-231 cells

Cytotoxic activity of 16 Hypericum ethanolic extracts was evaluated by MTT assay on two human cancer cell lines: glioblastoma A1235 and breast cancer MDA MB-231. Morphology and the type of induced cell death were determined using light and fluorescence microscopy. The majority of Hypericum extracts had no significant cytotoxic effect on MDA MB-231 cells. Eight extracts exhibited mild cytotoxic effect on A1235 cells after 24 h incubation, ranging from 8.0% (H. patulum) to 21.7% (H. oblongifolium). After 72 h of treatment, the strongest inhibition of A1235 viability was observed for extracts of H. androsaemum (26.4-43.9%), H. balearicum (25.8-36.3%), H. delphicum (14.8-27.4%) and H. densiflorum (11.2-24.1%). Micro-scopic examination of cells showed apoptosis as the dominant type of cell death. Due to observed high viability of treated cells, we propose that cytotoxic effects of Hypericum extracts could be related to alternations/interruptions in the cell cycle.

Bioactive effects of quercetin in the central nervous system: Focusing on the mechanisms of actions

Quercetin, a ubiquitous flavonoid that is widely distributed in plants is classified as a cognitive enhancer in traditional and oriental medicine. The protective effects of quercetin for the treatment of neurodegenerative disorders and cerebrovascular diseases have been demonstrated in both in vitro and in vivo studies. The free radical scavenging activity of quercetin has been well-documented, wherein quercetin has been observed to exhibit protective effects against oxidative stress mediated neuronal damage by modulating the expression of NRF-2 dependent antioxidant responsive elements, and attenuation of neuroinflammation by suppressing NF-κB signal transducer and activator of transcription-1 (STAT-1). Several in vitro and in vivo studies have also shown that quercetin destabilizes and enhances the clearance of abnormal protein such as beta- amyloid peptide and hyperphosphorlyated tau, the key pathological hallmarks of Alzheimer's disease. Quercetin enhances neurogenesis and neuronal longevity by modulating a broad number of kinase signaling cascades such as phophoinositide 3- kinase (P13-kinase), AKT/PKB tyrosine kinase and Protein kinase C (PKC). Quercetin has also been well reported for its ability to reverse cognitive impairment and memory enhancement during aging. The current review focuses on summarizing the recent findings on the neuroprotective effect of quercetin, its mechanism of action and its possible roles in the prevention of neurological disorders.

Biochemical Characterization and Antimicrobial and Antifungal Activity of Two Endemic Varieties of Garlic (Allium sativum L.) of the Campania Region, Southern Italy

Extracts of the bulbs of the two endemic varieties "Rosato" and "Caposele" of Allium sativum of the Campania region, Southern Italy, were analyzed. The phenolic content, ascorbic acid, allicin content, and in vitro antimicrobial and antifungal activity were determined. Ultra performance liquid chromatography with diode array detector performed polyphenol profile. The polyphenolic extracts showed antioxidant activity (EC50) lower than 120 mg. The amount of ascorbic acid and allicin in the two extracts was similar. Polyphenol extract exhibited antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and (only by the extract of Rosato) against Bacillus cereus. The extract of Caposele was more effective in inhibiting the growth of Aspergillus versicolor and Penicillum citrinum. On the other hand, the extract of Rosato was effective against Penicillium expansum.

Hyperoside Induces Endogenous Antioxidant System to Alleviate Oxidative Stress

Background:

Hyperoside, a flavonoid which is mainly found in Hypericum perforatum L., has many biological effects. One of the most important effects is to prevent the oxidative stress induced by reactive oxygen species. However, the molecular mechanisms underlying its effect are not fully understood. Oxidative stress is implicated in the occurrence of various physical diseases. A wide array of enzymatic antioxidant defense systems include NADH: quinone oxidoreductase 1, superoxide dismutase, and heme oxygenase-1 (HO-1). In the present study, the protective effects of hyperoside against hydrogen peroxide-induced oxidative stress in human lens epithelial cells, HLE-B3, were investigated in terms of HO-1 induction.

Methods:

The protein and mRNA expressions of HO-1 were examined by Western blotting and reverse transcriptase-PCR assays, respectively. To evaluate the ability of hyperoside to activate nuclear factor erythroid 2-related factor 2 (Nrf2), Western blotting and electrophoretic mobility shift assay were performed with nuclear extracts prepared from HLE-B3 cells treated with hyperoside. The activation of extracellular signal-regulated kinase (ERK), the upstream kinase of Nrf2 signaling, was monitored by Western blot analysis. The protective effect of hyperoside in HLE-B3 cells against hydrogen peroxide was performed by MTT assay.

Results:

Hyperoside increased both the mRNA and protein expression of HO-1 in a time- and dose-dependent manner. In addition, hyperoside elevated the level of of Nrf2 and its antioxidant response element-binding activity, which was modulated by upstream of ERK. Moreover, it activated ERK and restored cell viability which was decreased by hydrogen peroxide.

Conclusions:

Hyperoside is an effective compound to protect cells against oxidative stress via HO-1 induction.

Neuroprotective Activity of Hypericum perforatum and Its Major Components

Hypericum perforatum is a perennial plant, with worldwide distribution, commonly known as St. John's wort. It has been used for centuries in traditional medicine for the treatment of several disorders, such as minor burns, anxiety, and mild to moderate depression. In the past years, its antidepressant properties have been extensively studied. Despite that, other H. perforatum biological activities, as its neuroprotective properties have also been evaluated. The present review aims to provide a comprehensive summary of the main biologically active compounds of H. perforatum, as for its chemistry, pharmacological activities, drug interactions and adverse reactions and gather scattered information about its neuroprotective abilities. As for this, it has been demonstrated that H. perforatum extracts and several of its major molecular components have the ability to protect against toxic insults, either directly, through neuroprotective mechanisms, or indirectly, through is antioxidant properties. H. perforatum has therefore the potential to become an effective neuroprotective therapeutic agent, despite further studies that need to be carried out.

Ligustrazinyl amides: a novel class of ligustrazine-phenolic acid derivatives with neuroprotective effects

Background

Ligustrazine has potent effects of thrombolysis, neuroprotection and vascular protection, which were important for effectively protecting the nervous system. Previous study in our laboratory reported that ligustrazine-benzoic acid derivatives have been shown to exhibit beneficial effect against CoCl₂-induced neurotoxicity in differentiated PC12 cells. To further improve ligustrazine’s neuroprotection, we integrated the ligustrazine and phenolic acid fragments into one molecule via an amide bond based on structural combination.

Results

In this study, 12 novel ligustrazine-phenolic acid derivatives were synthesized and nine others were prepared by improved methods. Furthermore, these compounds were evaluated for their protective effects against CoCl₂-induced neurotoxicity in differentiated PC12 cells. The amides conjunctional derivatives exhibited promising neuroprotective activities in comparison with ligustrazine. In addition, the most active congener (E)-3-(2,3,4-trimethoxyphenyl)-N-((3,5,6-trimethylpyrazin-2-yl)methyl)acrylamide (L10, EC₅₀ = 25 μM), which is 2 times higher than that of ligustrazine, may be a potential candidate for intervention in neurological diseases. Structure-activity relationship was discussed briefly.

Conclusions

Results of series of ligustrazinyl amides enrich the study of ligustrazine derivatives with neuroprotective effects. Our completed work supports that the attempt to apply structure combination to discover more efficient neuroprotection lead compounds is viable.

Graphical Abstract