Anti-proliferative effect of Juglone from Juglans mandshurica Maxim on human leukemia cell HL-60 by inducing apoptosis through the mitochondria-dependent pathway

Comprehensive Characterization of Phytochemical Composition, Membrane Permeability, and Antiproliferative Activity of Juglans nigra Polyphenols

The aim of our study was the detailed polyphenol profiling of Juglans nigra and the characterization of the membrane permeability and antiproliferative properties of its main phenolics. A total of 161 compounds were tentatively identified in J. nigra bark, leaf, and pericarp extracts by ultrahigh-performance liquid chromatography-high-resolution tandem mass spectrometry (UHPLC-HR-MS/MS). Eight compounds including myricetin-3-O-rhamnoside (86), quercetin-3-O-rhamnoside (106), quercetin-3-O-xyloside (74), juglone (141), 1,2,3,4-tetrahydro-7,8-dihydroxy-4-oxonaphthalen-1-yl-6-O-galloyl-glucoside (92), ellagic acid (143), gallic acid (14), and ethyl gallate (58) were isolated from J. nigra pericarp. The in vitro antiproliferative activity of the isolated compounds was investigated against three human cancer cell lines, confirming that juglone (141) inhibits cell proliferation in all of them, and has similar activity as the clinical standards. The permeability of the isolated compounds across biological membranes was evaluated by the parallel artificial membrane permeability assay (PAMPA). Both juglone (141) and ethyl-gallate (58) showed positive results in the blood-brain-barrier-specific PAMPA-BBB study. Juglone (141) also possesses logPe values which indicates that it may be able to cross both the GI and BBB membranes via passive diffusion.

Enrichment and Evaluation of Antitumor Properties of Total Flavonoids from Juglans mandshurica Maxim

Flavonoids are important secondary metabolites found in Juglans mandshurica Maxim., which is a precious reservoir of bioactive substances in China. To explore the antitumor actions of flavonoids (JMFs) from the waste branches of J. mandshurica, the following optimized purification parameters of JMFs by macroporous resins were first obtained. The loading concentration, flow rate, and loading volume of raw flavonoid extracts were 1.4 mg/mL, 2.4 BV/h, and 5 BV, respectively, and for desorption, 60% ethanol (4 BV) was selected to elute JMFs-loaded AB-8 resin at a flow rate of 2.4 BV/h. This adsorption behavior can be explained by the pseudo-second-order kinetic model and Langmuir isotherm model. Subsequently, JMFs were identified using Fourier transform infrared combined with high-performance liquid chromatography and tandem mass spectrometry, and a total of 156 flavonoids were identified. Furthermore, the inhibitory potential of JMFs on the proliferation, migration, and invasion of HepG2 cells was demonstrated. The results also show that exposure to JMFs induced apoptotic cell death, which might be associated with extrinsic and intrinsic pathways. Additionally, flow cytometry detection found that JMFs exposure triggered S phase arrest and the generation of reactive oxygen species in HepG2 cells. These findings suggest that the JMFs purified in this study represent great potential for the treatment of liver cancer.

A Multiplex PCR System of Novel Microsatellite Loci for Population Genetic Application in Walnuts

Multiplex polymerase chain reaction (PCR) of microsatellite loci allows for simultaneous amplification of two or more pairs of primers in a single PCR reaction; hence, it is cost and time effective. However, very few attempts have been reported in non-model species. In this study, by combining a genome-based de novo development and cross-species application approach, a multiplex PCR system comprising 5 PCR reactions of 33 microsatellites consisting of 26 novel genomic and 7 literature-sourced loci was tested for polymorphisms, cross-species transferability, and the ability to assess genetic diversity and population structure of three walnut species (Juglans spp.). We found that the genome-based approach is more efficient than other methods. An allelic ladder was developed for each locus to enhance consistent genotyping among laboratories. The population genetic analysis results showed that all 33 loci were successfully transferred across the three species, showing high polymorphism and a strong genetic structure. Hence, the multiplex PCR system is highly applicable in walnut species. Furthermore, we propose an efficient pipeline to characterize and genotype polymorphic microsatellite loci. The novel toolbox developed here will aid future ecology and evolution studies in walnut and could serve as a model for other plant species.

Juglans mandshurica Maximowicz as a traditional medicine: review of its phytochemistry and pharmacological activity in East Asia

OBJECTIVES

The conducted search reveals that Juglans mandshurica Maximowicz, called Manchuria walnuts, had many local uses that can be categorized into cancer, dermatosis and acesodyne.

KEY FINDINGS

Various metabolites including diarylheptanoids, naphthoquinones, and flavonoids (also their glycosides) were reported as bioactive metabolites. The isolated metabolites and extracts from J. mandshurica showed different biological activity including cytotoxicity, anti-inflammation, antimelanotic, anticomplement, anti-HIV, antimicrobial and anti-obesity activity.

SUMMARY

It is indicated that this review will add value to more scientific research on J. mandshurica and enhance the increased interest in the sustainable commercialization of J. mandshurica. It also leads to the validation of unverified ethnobotanical claims. Future studies on J. mandshurica would be focused to establish the links between the pharmacological activity, bioactive metabolites, and traditional uses.

Advances in research on the relationship between thymoquinone and pancreatic cancer

Pancreatic cancer has one of the worst prognoses among the most common cancers in the world. Its characteristics include a high rate of metastasis and chemotherapeutic resistance, which present major challenges to the medical community. The potential anticancer effects of thymoquinone (TQ), which is the main bioactive compound of the black seeds of the Nigella sativa plant, have recently received widespread attention for their potential use in treating pancreatic cancer. TQ can inhibit cell proliferation, promote cancer cell apoptosis, inhibit cell invasion and metastasis, enhance chemotherapeutic sensitivity, inhibit angiogenesis, and exert anti-inflammatory effects. These anticancer effects predominantly involve the nuclear factor (NF)-κB, phosphoinositide 3 kinase (PI3K)/Akt, Notch, transforming growth factor (TGF)-β, c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) signaling pathways as well as the regulation of the cell cycle, matrix metallopeptidase (MMP)-9 expression, and pyruvate kinase isozyme type M2 (PKM2) activity. TQ regulates the occurrence and development of pancreatic cancer at multiple levels and through multiple targets that communicate with each other. In this review, we summarize and discuss the analogs and carriers of TQ that have been developed in recent years. Given its multilevel anticancer effects, TQ may become a new therapeutic drug for treating pancreatic cancer in the future. This review presents a brief introduction to the research that has been conducted on TQ in relation to pancreatic cancer to provide a theoretical basis for future studies on the topic.

Naphthoquinones and derivatives as potential anticancer agents: An updated review

One of the leading global causes of death is cancer; even though several treatment methods have improved survival rates, the incidence and fatality rates remain high. Naphthoquinones are a type of quinone that is found in nature and has vital biological roles. These chemicals have anticancer (antineoplastic), analgesic, anti-inflammatory, antimalarial, antifungal, antiviral, antitrypanosomal, antischistosomal, leishmanicidal, and anti-ulcerative effects. Direct addition of a substituent group to the 1,4-naphthoquinone ring can alter the naphthoquinone's oxidation/reduction and acid/base characteristics, and the activity can be altered. Because of their pharmacological properties, such as anticancer activity and probable therapeutic application, naphthoquinones have greatly interested the scientific community. Some chemicals having a quinone ring in malignant cells have been found to have antiproliferative effects. Naphthoquinones' deadly impact is connected with the inhibition of electron transporters, the uncoupling of oxidative phosphorylation, the creation of ROS, and the formation of protein adducts, notably with -SH enzyme groups. This review article aims to discuss naphthoquinones and their derivatives, which act against cancer and their future perspectives. This review covers several studies highlighting the potent anticancer properties of naphthoquinones. Further, various proposed mechanisms of anticancer actions of naphthoquinones have been summarized in this review.

Juglone from Walnut Produces Cardioprotective Effects against Isoproterenol-Induced Myocardial Injury in SD Rats

Therapeutic and/or preventive interventions using phytochemical constituents for ischemic heart disease have gained considerable attention worldwide, mainly due to their antioxidant activity. This study investigated the cardioprotective effect and possible mechanism of juglone, a major constituent of the walnut tree, using an isoproterenol (ISO)-induced myocardial infarction (MI) model in rats. Rats were pretreated for five (5) days with juglone (1, 3 mg/kg, i.p) and atenolol (1 mg/kg, i.p) in separate experiments before inducing myocardial injury by administration of ISO (80 mg/kg, s.c) at an interval of 24 h for 2 consecutive days (4th and 5th day). The cardioprotective effect of juglone was confirmed through a lead II electrocardiograph (ECG), cardiac biomarkers (cTnI, CPK, CK-MB, LDH, ALT and AST) and histopathological study. The results of our present study suggest that prior administration of juglone (1 and 3 mg/kg) proved to be effective as a cardioprotective therapeutic agent in reducing the extent of myocardial damage (induced by ISO) by fortifying the myocardial cell membrane, preventing elevated T-waves, deep Q-waves in the ECG, heart to body weight ratio, infarction and also by normalizing cardiac marker enzymes (cTnI, CPK, CK-MB, LDH, ALT and AST) and histopathological changes, such as inflammation, edema and necrosis. In conclusion, this study has identified phytochemical constituents, in particular juglone, as a potential cardioprotective agent.

Antitumor Effect of Glandora rosmarinifolia (Boraginaceae) Essential Oil through Inhibition of the Activity of the Topo II Enzyme in Acute Myeloid Leukemia

It was previously shown that the antitumor and cytotoxic activity of the essential oil (EO) extracted from the aerial parts of Glandora rosmarinifolia appears to involve a pro-oxidant mechanism in hepatocellular carcinoma (HCC) and in triple-negative breast cancer (TNBC) cell lines. Its most abundant compound is a hydroxy-methyl-naphthoquinone isomer. Important pharmacological activities, such as antitumor, antibacterial, antifungal, antiviral and antiparasitic activities, are attributed to naphthoquinones, probably due to their pro-oxidant or electrophilic potential; for some naphthoquinones, a mechanism of action of topoisomerase inhibition has been reported, in which they appear to act both as catalytic inhibitors and as topoisomerase II poisons. Our aim was to evaluate the cytotoxic activity of the essential oil on an acute myeloid leukemia cell line HL-60 and on its multidrug-resistant (MDR) variant HL-60R and verify its ability to interfere with topoisomerase II activity. MTS assay showed that G. rosmarinifolia EO induced a decrease in tumor cell viability equivalent in the two cell lines; this antitumor effect could depend on the pro-oxidant activity of EO in both cell lines. Furthermore, G. rosmarinifolia EO reduced the activity of Topo II in the nuclear extracts of HL-60 and HL-60R cells, as inferred from the inability to convert the kinetoplast DNA into the decatenated form and then not inducing linear kDNA. Confirming this result, flow cytometric analysis proved that EO induced a G0-G1 phase arrest, with cell reduction in the S-phase. In addition, the combination of EO with etoposide showed a good potentiation effect in terms of cytotoxicity in both cell lines. Our results highlight the antitumor activity of EO in the HL-60 cell line and its MDR variant with a peculiar mechanism as a Topo II modulator. Unlike etoposide, EO does not cause stabilization of a covalent Topo II-DNA intermediate but acts as a catalytic inhibitor. These data make G. rosmarinifolia EO a potential anticancer drug candidate due to its cytotoxic action, which is not affected by multidrug resistance.

Impact of Group II Baculovirus IAPs on Virus-Induced Apoptosis in Insect Cells

Apoptosis plays an important role in virus-host interactions and is a major element of the insect immune response. Exploring the regulatory mechanisms of virus-induced apoptosis through the expression of apoptotic genes holds important research and application value. Functional research on the reported inhibitor of apoptosis proteins (IAPs) mainly focuses on the group I baculovirus, while the functions of the group II baculovirus IAPs remains unclear. To explore its role in the regulation of the apoptosis of insect cells, we constructed the transient expression vector (pIE1 vectors) and the recombinant baculovirus expressing Bsiap genes (from the Buzura suppressaria nucleopolyhedrovirus) of the group II baculovirus. Apoptosis gene expression results and the virus-induced apoptosis rate show that the overexpression of BsIAP1 could promote apoptosis in insect cells. However, the overexpression of BsIAP2 and BsIAP3 decreases the expression of apoptotic genes, revealing an inhibitory effect. Results on the impact of baculovirus-induced apoptosis also confirm that BsIAP1 reduces viral nucleocapsid expression and the baculovirus titer, while BsIAP2 and BsIAP3 increase them significantly. Furthermore, compared with single expression, the co-expression of BsIAP2 and BsIAP3 significantly reduces the rate of virus-induced apoptosis and improves the expression of nucleocapsids and the titer of offspring virus, indicating the synergistic effect on BsIAP2 and BsIAP3. In addition, combined expression of all three BsIAPs significantly reduced levels of intracellular apoptosis-related genes (including apoptosis and anti-apoptosis genes), as well as apoptosis rate and progeny virus titer, indicating that life activities in insect cells are also inhibited. These findings reveal the relationship between apoptosis and group II baculovirus IAP, which provide an experimental and theoretical basis for further exploration of the molecular mechanism between group II baculoviruses and insect cells.

Traditional uses, phytochemistry, pharmacology and clinical applications of Cortex Juglandis Mandshuricae: A comprehensive review

ETHNOPHARMALOGICAL RELEVANCE

Cortex Juglandis Mandshuricae (CJM) is the dry branch or stem bark of the Juglans mandshurica Maxim. and is widely used as a traditional Chinese medicine in Asia and Africa. Its use was first recorded in Kaibao Bencao.

AIM OF THE STUDY

The present review provides a deeper insight, better awareness and detailed knowledge of phytochemistry, pharmacology, quality control, along with clinical applications of Cortex Juglandis Mandshuricae.

METHODS

The relevant information of Cortex Juglandis Mandshuricae was obtained from several databases including Web of Science, PubMed, and CNKI. The medical books, PhD and MSc dissertations in Chinese were also used to perform this work.

RESULTS

CJM has been traditionally used against a wide range of diseases, including dysentery, acute conjunctivitis, bacterial infections, and cancer. A total of 249 compounds have been isolated from CJM; they mainly include quinones and their derivatives, flavonoids, tannins, diarylheptanoids, triterpenoids, coumarins, phenylpropanoids, and volatile oils. These compounds exert anti-tumor, anti-oxidant, anti-inflammatory, bacteriostatic, anti-complement, immunomodulatory, anti-parasitic activities. Specifically, the effects of juglone, alkaloids and unsaturated fatty acid CJM components against hepatic cancer occur through exertion of apoptosis through a mitochondria-dependent pathway. In addition, taxifolin and several tannins have been found to have anti-HIV activity, and (±)-juglanaloid A and (±)-juglanaloid B target Alzheimer disease. Quality control is monitored through identification of juglone, quercetin, and volatile oils. A clinical preparation of CJM, Compound Muji Granules, is used in the treatment of various liver diseases with good therapeutic effect.

CONCLUSION

While CJM has been used extensively as a folk medicine, the relationships between structure and activity remain unclear. More in vivo models are needed to study the pharmacological mechanisms of action and to assess potential toxic components, in addition to which the evidence used to demonstrate the quality standards of medicinal materials is clearly inadequate. Therefore, more in-depth research is needed to provide a reasonable scientific basis improve its clinical utilization.

Simultaneous Quantification of Diarylheptanoids and Phenolic Compounds in Juglans mandshurica Maxim. by UPLC–TQ-MS

The immature epicarps of Juglans mandshurica and Juglans regia have been used as folk medicine for the treatment of cancer in China. Other parts of the J.mandshurica plant, including leaves, branches, barks, and stems, have reported antitumor activities. We previously found that various diarylheptanoids and phenolic compounds isolated from J. mandshurica epicarps show significant antitumor activities. However, there are no reports of quantitative analysis of diarylheptanoids and phenolic compounds of J. mandshurica. In this study, a validated quantitative method, based on ultraperformance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry, was employed to determine the contents of eight diarylheptanoids and seven phenolic compounds in the epicarps of J. mandshurica during different growth periods, in different parts of the plant, and in the epicarps of two Juglans species. The most successful J. mandshurica epicarp harvesting time fell between Day 12 and Day 27. The leaves of J. mandshurica showed potential for medical use as they had the highest content of the 15 compounds (3.399 ± 0.013 mg/g). We showed for the first time that the total content of diarylheptanoids in J. mandshurica is higher than that in J. regia, though, conversely, J. regia has higher contents of phenolic compounds. The method developed in this study is practical and simple and can be applied for quantitative analysis for evaluating the intrinsic quality of J. mandshurica.

Toxicity evaluation of Eleutherine plicata Herb. extracts and possible cell death mechanism

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Ethanol extract of Eleutherine plicata showed low in vitro and in vivo cytotoxic potential.

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The dichloromethane fraction was cytotoxic to HepG2 and caused DNA. However, no toxicity was observed in vivo.

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Isoeleutherin caused DNA damage by the comet method and activated caspase-8 in the in silico study.

Eleutherine plicata has been shown to be a promising medicinal plant, and its activity has been associated with naphthoquinones. The present study aimed at evaluating the cytotoxicity, genotoxicity, and oral toxicity of the ethanol extract (EEEp), dichloromethane fraction (FDMEp) of E. plicata, and isoeleutherin. For the cytotoxicity evaluation, the viability test (MTT) was used. Genotoxicity was accessed through the Comet assay (alkaline version), acute and subacute oral toxicities were also evaluated. The antioxidant capacity of the samples in the wells where the cells were treated with E. plicata was evaluated. Furthermore, the participation of caspase-8 in the possible mechanism of action of isoeleutherin, eleutherin, and eleutherol was also investigated through a docking study. FDMEp and isoeleutherin were cytotoxic, with higher rates of DNA fragmentation observed for FDMEp and isoeleutherin, and all samples displayed higher antioxidant potential than the control. In the acute oral toxicity test, EEEp, FDMEp, and isoeleutherin did not cause significant clinical changes. In the subacute toxicity assay, EEEp and FDMEp also did not cause clinical, hematological, or biochemical changes. The three compounds bound similarly to caspase-8. Despite the results of cytotoxicity, in vitro studies demonstrated that the use of EEEp appears to be safe and cell death may involve its binding to caspase-8.

Pseudo-ginsenoside Rh2 Induces Protective Autophagy in Hepatocellular Carcinoma HepG2 Cells

BACKGROUND

Pseudo-ginsenoside-Rh2 (pseudo-G-Rh2), a novel derivative of ginsenoside Rh2, is reported to exert a pro-apoptotic effect on various malignancies. However, whether this anti-cancer action of pseudo-G-Rh2 involves autophagy remains to be determined and explored.

OBJECTIVES

Investigation of pseudo-G-Rh2-induced apoptosis and autophagy and the underlying mechanism.

METHODS

In the present study, the MTT assay was used for evaluating cell viability and the lactate dehydrogenase (LDH) assay was performed to assess cell toxicity. Autophagy evaluation was performed using monodansylcadaverine (MDC) staining and transmission electron microscopy (TEM). The levels of autophagy-associated and apoptosis-associated proteins were determined using Western blotting. The Annexin V FITC/propidium iodide (PI) assay was used to assess apoptosis.

RESULTS

The Annexin V FITC/PI assay revealed that the percentage of apoptotic cells in HepG2 cells at concentrations 0, 20, 40, and 60 μM was 3.75%±1.37%, 5.70%±1.04%, 12.30%±2.10%, and 34.26%±4.73%, respectively. Pseudo-G-Rh2 was observed to significantly increase the expressions of BAX, cleaved-caspase-3, and cleaved-caspase-9, while it decreased the Bcl-2 expression. MDC and TEM analyses revealed that pseudo-G-Rh2 at concentrations 20, 40, and 60 μM significantly facilitated the accumulation of autophagosomes and autolysosomes within the HepG2 cells. Moreover, pseudo-G-Rh2 significantly increased the expressions of LC3 Ⅱ/LC3 Ⅰ, and Beclin-1 and decreased the expression of p62. The Annexin V FITC/PI assay also revealed that in comparison to the pseudo-G-Rh2 group, the concurrent treatment with pseudo-G-Rh2 and an autophagy inhibitor (CQ or 3-MA) significantly induced distinct apoptosis. In addition, pseudo-G-Rh2 activated AMPK and inhibited the PI3K/Akt/mTOR pathway in a concentration-dependent manner. Pseudo-G-Rh2 is similar to the current patents, which enhanced its anti-cancer activity by combining with autophagy inhibitors.

CONCLUSION

Pseudo-G-Rh2 could induce protective autophagy in HepG2 cells, at least in part, via AMPK and the PI3K/Akt/mTOR pathway.

Amelioration of cognitive deficit in zebrafish by an undescribed anthraquinone from Juglans regia L.: An in-silico, in-vitro and in-vivo approach

An undescribed anthraquinone assigned as 1-Hydroxy-5,5-dimethyl-5,6,7,8-tetrahydro-9,10-anthraquinone (compound 1) was isolated from ethylacetate extract of Juglans regia L. The structure of the compound was established on the basis of 1D, 2D NMR (HSQC, HMBC, COSY), ESI-QTOF-MS/MS spectroscopy. The molecular docking studies of compound 1 indicated similar molecular interactions as that of co-crystalized inhibitor. Compound 1 showed hydrogen bonds with residues PHE295, GLY121, π-σ interactions with TYR 341, π-π interactions with HIS 447 residues, and π-alkyl with TRP86 and TYR 337. On the basis of in-silico interaction studies of compound 1 with proteins, it was tested using acetylcholinesterase inhibition assay, acrylamide-induced neurotoxicity test of zebrafish larva, and scopolamine-induced cognitive deficit model of adult zebrafish. The compound 1 showed potent acetylcholinesterase inhibition activity, prevented acrylamide-induced neurotoxicity and improved learning and memory functions in T-maze test. The results established compound 1 to be a potential neuroprotective natural product for amelioration of cognitive impairment.

Potential Anti-Tumor Activity of Kefir-Induced Juglone and Resveratrol Fractions Against Ehrlich Ascites Carcinoma-Bearing BALB/C Mice

We investigated the potential influence of kefir-induced juglone and resveratrol fractions (JRK) against Ehrlich Ascites Carcinoma (EAC) bearing BALB/c male mice. Kefir yeast was grown in the cell culture supplemented with juglone and resveratrol (1:2). After 48 h incubation, JRK solution was applied (0.1 mL/day i.p.) to the EAC-bearing mice throughout five days. Molecular regulatory mechanisms of apoptotic and anti-apoptotic pathway components were evaluated in the plasma of mice and isolated EAC cells with ELISA, qRT-PCR, and immunocytchemical experiments. EAC-induced upregulation in Bcl-2 and downregulation in Caspase-3 were normalized with JRK in the plasma of mice. Additionally, JRK upregulated the expression levels of apoptotic Bax, p53, Caspase-3,8,9, and APAF-1 proteins together with BAX, CASPASE-8, and CASPASE-9 genes in isolated EAC cells. These changes were also associated with decreased expression levels of anti-apoptotic Bcl-2 and Bcl-xl proteins. Immunocytochemical studies also confirmed the activation of apoptotic pathways and repression of anti-apoptotic proteins in EAC cells with JRK treatment. JRK activates apoptotic pathway and inhibits anti-apoptotic genes and proteins in Ehrlich ascites carcinoma- bearing BALB/c mice that could be beneficial in cancer treatment.

Juglans mandshurica Maxim.: A Review of Its Traditional Usages, Phytochemical Constituents, and Pharmacological Properties

Juglans mandshurica Maxim., also known as “Manchurian walnut” (Chinese) and “Onigurumi” (Japanese), is a medicinal plant widely distributed in Western and Central Asia, especially in China. It has been traditionally used to treat cancer, gastric ulcers, diarrhea, dysentery, dermatosis, uterine prolapse, and leukopenia. To date, more than 400 constituents including quinones (e.g. naphthoquinones, anthraquinones, naphthalenones, tetralones), phenolics, flavonoids, triterpenoids, coumarins, lignans, phenylpropanoids, diarylheptanoids, and steroids, were isolated and structurally identified from different plant parts of J. mandshurica. Among them, quinones, phenolics, triterpenoids, and diarylheptanoids, as the major bioactive substances, have been extensively studied and displayed significant bioactivity. Previous studies have demonstrated that J. mandshurica and a few of its active components exhibit a wide range of pharmacologically important properties, such as antitumor, immunomodulatory, anti-inflammatory, neuroprotective, anti-diabetic, antiviral, antimicrobial, and anti-melanogenesis activities. However, many investigations on biological activities were mainly based on crude extracts of this plant, and the major bioactive ingredients responsible for these bioactivities have not been well identified. Further in vitro and in vivo studies on the mechanisms of action of the pure bioactive compounds, and more elaborate toxicity studies as well as clinical studies are needed to ensure safety and effectiveness of the plant for human use. Taken together, the present review will provide some specific useful suggestions guide to further investigations and applications of this plant in the preparation of medicines and functional foods.

Two new quinones and six additional metabolites with potential anti-inflammatory activities from the roots of Juglans mandshurica

Two new quinones, 4-(5-hydroxy-1,4-dioxo-1,4-dihydronaphtha-len-3-ylamino)-butyric acid methyl ester (compound 1) and 1,3-dimethoxycarbonyl-8-hydroxy-9,10-anthraquinone (2), and six known compounds (3-8) were isolated from the roots of Juglans mandshurica Maxim., a member of the Juglandaceae family. The chemical structures of the compounds were elucidated by nuclear magnetic resonance spectroscopy and compared with data from the literature. The isolated compounds were evaluated for their ability to inhibit the production of nitric oxide, tumour necrosis factor-α, and interleukin-6 by the mouse macrophage RAW 264.7 cell line after lipopolysaccharide stimulation in vitro. We found that compounds 1-4 exhibited potent anti-inflammatory effects, as indicated by suppression of lipopolysaccharide-stimulated nitric oxide and cytokine production with 50% inhibitory concentrations between 20.09 μM and 27.63 μM. These results identify two novel quinones from J. mandshurica with potential utility as anti-inflammatory compounds.

Notch3 contributes to T-cell leukemia growth via regulation of the unfolded protein response

Unfolded protein response (UPR) is a conserved adaptive response that tries to restore protein homeostasis after endoplasmic reticulum (ER) stress. Recent studies highlighted the role of UPR in acute leukemias and UPR targeting has been suggested as a therapeutic approach. Aberrant Notch signaling is a common feature of T-cell acute lymphoblastic leukemia (T-ALL), as downregulation of Notch activity negatively affects T-ALL cell survival, leading to the employment of Notch inhibitors in T-ALL therapy. Here we demonstrate that Notch3 is able to sustain UPR in T-ALL cells, as Notch3 silencing favored a Bip-dependent IRE1α inactivation under ER stress conditions, leading to increased apoptosis via upregulation of the ER stress cell death mediator CHOP. By using Juglone, a naturally occurring naphthoquinone acting as an anticancer agent, to decrease Notch3 expression and induce ER stress, we observed an increased ER stress-associated apoptosis. Altogether our results suggest that Notch3 inhibition may prevent leukemia cells from engaging a functional UPR needed to compensate the Juglone-mediated ER proteotoxic stress. Notably, in vivo administration of Juglone to human T-ALL xenotransplant models significantly reduced tumor growth, finally fostering the exploitation of Juglone-dependent Notch3 inhibition to perturb the ER stress/UPR signaling in Notch3-dependent T-ALL subsets.

Naphthoquinones from Handroanthus impetiginosus promote skin wound healing through Sirt3 regulation

Objective(s):

Lapachone is a natural naphthoquinone-derived compound found in Tabebuia avellanedae. It is well-known for its analgesic, anti-inflammatory, anti-microbial, diuretic, and anti-cancerous effects. However, the wound-healing effects of this compound are not known yet. The aim of this study was to investigate the wound healing activity of naphthoquinones (α-lapachone and β-lapachone) from Handroanthus impetiginosus.

Materials and Methods:

Expression of Sirt3, migration-related proteins (Rac1, Cdc42, α-Pak) and angiogenesis-related protein of vascular endothelial growth factor (VEGF) was monitored using western blot analysis. Blood vessel formation and tissue development were monitored by angiogenesis assay and hematoxylin & eosin (H & E) staining, respectively on mouse skin tissue samples. Both α-lapachone and β-lapachone increased Sirt3 expression in vivo, but only β-lapachone increased Sirt3 expression in vitro.

Results:

Both the compounds accelerated wound healing in cultured skin cells as well as mouse skin; however, β-lapachone was more effective at lower concentrations. Both of the compounds increased the expression of migration-related proteins both in vitro and in vivo. Similarly, α-lapachone and β-lapachone increased VEGF expression, tissue development and blood vessel formation in mouse skin.

Conclusion:

These findings indicated that α-lapachone and β-lapachone are novel Sirt3 activators, and Sirt3 has a role in wound healing. Thus, Sirt3 and its regulators come out as a novel target and potential drug candidates, respectively in the important field of cutaneous wound healing.

Juglone potentiates BRAF inhibitor‑induced apoptosis in melanoma through reactive oxygen species and the p38‑p53 pathway

BRAF inhibitors are some of the most effective drugs against melanoma; however, their clinical application is largely limited by drug resistance. Juglone, isolated from walnut trees, has demonstrated anti‑tumour activity. In the present study, it was investigated whether juglone could enhance the responses to a BRAF inhibitor in melanoma cells (A375R and SK‑MEL‑5R) with an acquired resistance. These cells were treated with juglone alone, BRAF inhibitor (PLX4032) alone, or juglone combined with PLX4032. It was demonstrated that the combination of juglone and PLX4032 had synergistic effects on BRAF inhibitor‑resistant melanoma cells. Juglone potentiated PLX4032‑induced cytotoxicity and mitochondrial apoptosis in both A375R and SK‑MEL‑5R cells, which was accompanied by a decline in mitochondrial membrane potential and a decrease in Bcl‑2/Bax ratio. Moreover, juglone combined with PLX4032 markedly increased the intracellular level of reactive oxygen species (ROS) and activated p38 and p53, as compared with juglone alone or PLX4032 alone. Pre‑treatment with N‑acetyl‑L‑cysteine, a ROS scavenger, completely reversed the cytotoxicity induced by juglone combined with PLX4032. In conclusion, juglone potentiated BRAF inhibitor‑induced apoptosis in resistant melanoma cells, and these effects occurred partially through ROS and the p38‑p53 pathway, suggesting the potential of juglone as a sensitizer to BRAF inhibitors in the treatment of melanoma.

Mechanisms mediating the vasodilatory effects of juglone in porcine isolated coronary artery

Juglone (5-hydroxy-1, 4-naphthoquinone), is a natural phenolic compound that has been shown to relax smooth muscle. Therefore the aim of this study was to determine the effect of juglone on vascular tone using porcine coronary artery (PCA). Segments of PCA, with or without endothelium, were mounted for isometric tension recording in isolated tissue baths and precontracted with the thromboxane A₂ analog U46619 or KCl. After pre-contraction, cumulative concentrations of juglone were added to the tissues, in the presence or absence of a variety of inhibitors on intracellular signaling pathways. Juglone (10^-9 to 10^-5 M) produced a concentration-dependent relaxation of the PCA which was reduced in endothelium-denuded vessels, as well as in vessels pre-treated with the nitric oxide synthase inhibitor L-NAME, indicating that at least part of the effect of juglone is mediated through an endothelium, NO-dependent mechanism. Juglone also inhibited contractions in response to influx of extracellular calcium and release of intracellular calcium, indicating that juglone may inhibit a common signaling pathway downstream of calcium. Contractions to the protein kinase C activator Phorbol 12-myristate 13-acetate were also reduced by juglone, suggesting that juglone might be acting through inhibition of protein kinase C. In summary, juglone produces a relaxation of the porcine coronary artery through activation of the nitric oxide pathway and inhibition of calcium-induced contractions.

Analysis of the Mechanisms of Action of Naphthoquinone-Based Anti-Acute Myeloid Leukemia Chemotherapeutics

Acute myeloid leukemia (AML) is a neoplastic disorder resulting from clonal proliferation of poorly differentiated immature myeloid cells. Distinct genetic and epigenetic aberrations are key features of AML that account for its variable response to standard therapy. Irrespective of their oncogenic mutations, AML cells produce elevated levels of reactive oxygen species (ROS). They also alter expression and activity of antioxidant enzymes to promote cell proliferation and survival. Subsequently, selective targeting of redox homeostasis in a molecularly heterogeneous disease, such as AML, has been an appealing approach in the development of novel anti-leukemic chemotherapeutics. Naphthoquinones are able to undergo redox cycling and generate ROS in cancer cells, which have made them excellent candidates for testing against AML cells. In addition to inducing oxidative imbalance in AML cells, depending on their structure, naphthoquinones negatively affect other cellular apparatus causing neoplastic cell death. Here we provide an overview of the anti-AML activities of naphthoquinone derivatives, as well as analysis of their mechanism of action, including induction of reduction-oxidation imbalance, alteration in mitochondrial transmembrane potential, Bcl-2 modulation, initiation of DNA damage, and modulation of MAPK and STAT3 activity, alterations in the unfolded protein response and translocation of FOX-related transcription factors to the nucleus.

Photodynamic therapy using zinc phthalocyanine with low dose of diode laser combined with doxorubicin is a synergistic combination therapy for human SK-MEL-3 melanoma cells

Chemotherapy is a generally used anticancer strategy for melanoma and it may have improved outcomes in combination with other approaches. One such strategy is photodynamic therapy (PDT), where a photosensitizer (PS) generates reactive oxygen species (ROS) after illumination of target cells. Interestingly, in low doses and high doses of light sources, special cellular responses can be induced. Regarding this fact, in this study, the combination of zinc phthalocyanine (ZnPc)-PDT and Doxorubicin (DOX) was applied at low and high dose of diode laser to treat SK-MEL-3 cells. Cytotoxic effects were determined by MTT assay for assessment synergistic effects were estimated by calculation of Combination Index (CI); that synergistic effects were observed in most groups. In low dose of laser irradiation higher synergism effects were observed. Significant changes of ROS were not observed with combinations, but autophagy, subG1 and G2/M phase cell cycle arrest, decreased cell migration ability and apoptosis induction were significantly increased compared to either treatment alone. The expression of caspase-8, -9, -3 and Bcl-2 genes revealed caspase-dependent apoptosis in all groups. Moreover, ZnPc-PDT and chemo-PDT down-regulated the expression of MMP-9 and Vimentin genes that impaired cell migration. In conclusion, it can be suggested that pre-treatment with ZnPc-PDT has high effects to sensitize SK-MEL-3 cells to DOX, in particular with low dose of diode laser.

Juglone in Oxidative Stress and Cell Signaling

Juglone (5-hydroxyl-1,4-naphthoquinone) is a phenolic compound found in walnuts. Because of the antioxidant capacities of phenolic compounds, juglone may serve to combat oxidative stress, thereby protecting against the development of various diseases and aging processes. However, being a quinone molecule, juglone could also act as a redox cycling agent and produce reactive oxygen species. Such prooxidant properties of juglone may confer health effects, such as by killing cancer cells. Further, recent studies revealed that juglone influences cell signaling. Notably, juglone is an inhibitor of Pin1 (peptidyl-prolyl cis/trans isomerase) that could regulate phosphorylation of Tau, implicating potential effects of juglone in Alzheimer’s disease. Juglone also activates mitogen-activated protein kinases that could promote cell survival, thereby protecting against conditions such as cardiac injury. This review describes recent advances in the understanding of the effects and roles of juglone in oxidative stress and cell signaling.

Transthyretin Amyloid Fibril Disrupting Activities of Extracts and Fractions from Juglans mandshurica Maxim. var. cordiformis (Makino) Kitam

Transthyretin-related amyloidosis is a slowly progressive disorder caused by deposition of insoluble amyloid plaques formed by fibrillization of mutant or defective transthyretin (TTR) monomers that leads to neurodegeneration and organ failure. Thus, any compound exhibiting TTR amyloid formation inhibitory activity or TTR amyloid fibril disrupting activity might be a potential candidate for the development of therapies for these disorders. Our aim in this study was the evaluation of the TTR amyloid fibril disrupting potential of extracts of leaves and immature fruits of two Juglans plants, i.e., Juglans mandshurica var. sachalinensis and Juglans mandshurica var. cordiformis. The TTR amyloid fibril disrupting activity was measured by Thioflavin-T (ThT) assay and PROTEOSTAT^® Protein aggregation assay methods. A fifty percent acetone extract of the fruits of Juglans mandshurica var. cordiformis showed strong amyloid fibril disrupting activity, and was further fractionated using different solvents. Ethyl acetate and n-butanol fractions showed significant activity in both assays. Syringic acid was isolated and identified as main compound in both of these fractions; however, it did not show any activity. Furthermore, some of the previously reported compounds from Juglans plants including naphthoquinone derivatives and phenolic compounds were evaluated to identify the potential bioactive compounds. Among them, juglone, a naphthoquinone derivative showed promising activity. However, juglone also showed strong cytotoxicity in HEK293 cells. Thus, future studies should focus on the isolation and identification of naphthoquinone derivatives or other compounds from Juglans plan ts with potent bioactivity and low cytotoxicity.

Efficacy of 5-aminolevulinic acid-based photodynamic therapy against keloid compromised by downregulation of SIRT1-SIRT3-SOD2-mROS dependent autophagy pathway

Keloids exhibit cancer-like properties without spontaneous regression and usually recur post excision. Although photodynamic therapy (PDT) is a promising treatment, details of the mechanisms remain to be elucidated. In this study, we investigated mechanisms involved in 5-Aminolevulinic Acid (5-ALA)-based PDT against keloid. Found that 5-ALA-PDT induced superoxide anion-dependent autophagic cell death. Application of autophagy inhibitor 3-Methyladenine (3-MA) significantly prevented the effect that 5-ALA-PDT induced keloid-derived fibroblasts death, but Z-VAK-FMK (apoptotic inhibitor) did not. Interestingly, 5-ALA-PDT promoted the SIRT3 protein expression and the activity of mitochondrial superoxide dismutase 2 (SOD2), but SIRT1 protein expression level was decreased. SOD2 as a key enzyme can decrease mitochondrial ROS (mROS) level, Deacetylation of SOD2 by SIRT3 regulates SOD2 enzymatic activity has been identified. Then we explored SOD2 acetylation level with immunoprecipitation, found that 5-ALA-PDT significantly increased the acetylation levels of SOD2. In order to confirm deacetylation of SOD2 regulated by SIRT3, 3-TYP (SIRT3 inhibitor) was used. Found that inhibition of SIRT3 by 3-TYP significantly increased the level of SOD2 acetylation level compared with control group or 5-ALA-PDT group. To explore the connection of SIRT1 and SIRT3, cells were treated with EX527(SIRT1 inhibitor) or SRT1720 (SIRT1 activator), and EX527 increased SIRT3 protein level, however, SRT1720 displayed the opposite effect in the present or absence of 5-ALA-PDT. Moreover SIRT1-inhibited cells are more resistant to 5-ALA-PDT and showing decreased ROS accumulation. These results may demonstrate that 5-ALA-PDT induced SIRT1 protein level decreased, which promoted the effect of SIRT3 increased activity of SOD2 that can reduce mROS level, and then compromised 5-ALA-PDT induced autophagic cell death.

Overexpression of Hes1 is involved in sensitization of K562 cells to Imatinib

Tyrosine kinase inhibitor (TKI)-based therapy has created promising results among much chronic myeloid leukemia (CML) patients. Imatinib as a relatively specific inhibitor of Bcr-Abl is at present one of the undisputed therapeutic agent for newlydiagnosed patients with CML. However, the occurrence of imatinib-resistance enlightens the urgent need to identify other therapeutic agents against CML. Juglone (5-hydroxy-2-methyl-1, 4-naphthoquinone) exerts cytotoxic effects against various human cancer cell lines. However, the mechanisms through which Juglone induces anticancer effects in CML especially in comparison with imatinib treatment remain unknown. Our results revealed that Juglone-inhibited K562 cells growth through inducing apoptosis. Based on our Western blot analyses, Juglone significantly reduced p-Akt levels and increased the expression level of Forkhead box O1 (FoxO1) and FoxO3a proteins. Moreover, hairy/enhancer of split-1 (Hes1) protein, overexpressed under the influence of Juglone, is apparently involved in Juglone-induced apoptosis among K562 cells. Conversely, treatment with imatinib attenuated Hes1 protein expression. Considering the different functional mechanism of Juglone compared with imatinib, it seems that Juglone treatment could be a useful alternative strategy for the treatment of patients with imatinib-resistance.

FPOA induces apoptosis in HeLa human cervical cancer cells through a caspase-mediated pathway

In the present study, the triterpenoid 3-acetoxylanosta-8,24-dien-21-oic acid (FPOA) was extracted from Fomitopsis pinicola. The aim of the present was to elucidate the mechanism of action of FPOA in HeLa cervical cancer cells. Cell viability was examined using an MTT assay and the morphological detection of apoptosis was conducted using DAPI staining. The rate of apoptosis was examined via Annexin V-FITC/PI double staining and the expression levels of apoptosis-associated proteins were determined by western blot analysis. FPOA was observed to inhibit HeLa cell proliferation, with IC₅₀ values of 25.28, 15.30 and 11.79 µg/ml at 24, 48 and 72 h, respectively. Typical apoptotic bodies were observed in the HeLa cells following treatment with FPOA, as revealed by DAPI staining. The percentage of apoptotic cells was 3.00, 3.12, 6.18 and 32.28% following treatment with FPOA at concentrations of 0, 7.5, 15 and 30 µg/ml, respectively. Western blot analysis showed that caspase-3 and −9 were cleaved more frequently after treatment with FPOA. Furthermore, the expression of Bax was increased but Bcl-2 expression was decreased after treatment with FPOA. These results suggest that FPOA can induce HeLa cell apoptosis through a caspase-mediated pathway.

Pseudo-Ginsenoside Rh2 induces A549 cells apoptosis via the Ras/Raf/ERK/p53 pathway

Ginsenoside Rh2, a major effective constituent of ginseng, has been suggested to have a pro-apoptotic effect in a variety of cancer cells. Pseudo-Ginsenside-Rh2 (pseudo-G-Rh2) is a novel derivative of ginsenoside Rh2. The aim of the present study was to evaluate the effect of pseudo-G-Rh2 on the apoptosis of lung adenocarcinoma A549 cells. The cytotoxicity of pseudo-G-Rh2 on A549 cells was evaluated using an MTT assay. Apoptosis was detected using DAPI staining and flow cytometry. The expression of apoptosis associated proteins was identified by western blot analysis. The results demonstrated that pseudo-G-Rh2 inhibits the proliferation of A549 cells in a dose-dependent manner. DAPI staining revealed topical morphological changes in apoptotic bodies following pseudo-G-Rh2 treatment. Flow cytometric analysis revealed that the percentage of Annexin V-fluorescein isothiocyanate-positive cells, which are apoptotic, increased with pseudo-G-Rh2 treatment in a dose-dependent manner. Furthermore, treatment with pseudo-G-Rh2 increased the level of reactive oxygen species in A549 cells as well as the activation of caspase-9, caspase-3 and poly ADP-ribose polymerase. Pseudo-G-Rh2 treatment was observed to induce mitochondrial membrane potential loss. Furthermore, the results of western blotting revealed that B-cell lymphoma 2 (Bcl-2) expression was significantly decreased while Bcl-2-associated X protein expression was significantly upregulated in A549 cells with pseudo-G-Rh2 treatment. Pseudo-G-Rh2-induced apoptosis was accompanied by sustained phosphorylation of Ras, Raf, extracellular signal-regulated kinase (ERK) and p53. In conclusion, the results of the present study suggest that pseudo-G-Rh2 induces mitochondrial apoptosis in A549 cells and is responsible for excessive activation of the Ras/Raf/ERK/p53 pathway.

Juglone induces apoptosis and autophagy via modulation of mitogen-activated protein kinase pathways in human hepatocellular carcinoma cells

Juglone (JG), a naturally-occurring naphthoquinone of Manchurian walnut (Juglans mandshurica) was shown to inhibit proliferation in various tumor types. However, the molecular mechanisms of JG on the induction of apoptosis and autophagy in HepG2 cells have not been examined. Herein, we investigated that JG could inhibit cell proliferation by induction of G2/M phase arrest. Also, occurrence of apoptosis was closely related with loss of mitochondrial membrane potential, the changes of apoptosis-related proteins after treatment with JG. In addition, we found that JG caused autophagy, as evidenced by increased expressions of LC3-II and Beclin-1. Interestingly, inhibition of JG-induced autophagy by 3-methyladenine (3-MA) and wortmannin (WT) significantly decreased apoptosis, whereas the apoptosis inhibitor z-VAD-fmk slightly enhanced autophagy. Furthermore, the induction of autophagy and apoptosis was associated with activation of MAPK family members (p38 and JNK) and production of reactive oxygen species (ROS). Both JNK inhibitor (SP600125) and ROS scavenger (N-acetylcysteine, NAC) could attenuate JG-induced autophagy and apoptosis. However, the p38-specific inhibitor SB203580 enhanced autophagic and apoptotic death. Moreover, the ROS scavenger NAC prevented phosphorylation of both p38 and JNK. Collectively, our data revealed that JG induced G2/M phase arrest, apoptosis, and autophagy through the ROS-dependent signaling pathway.

Juglone potentiates TRAIL‑induced apoptosis in human melanoma cells via activating the ROS‑p38‑p53 pathway

Tumor necrosis factor‑related apoptosis‑inducing ligand (TRAIL)‑based cancer therapy offers promise as TRAIL can kill cancer cells without apparent toxicity towards normal cells. However, intrinsic or acquired resistance to TRAIL inseveral types of cancer cell has become a major challenge in TRAIL‑based cancer therapy. Juglone is a natural compound isolated from walnut trees. In the present study, it was demonstrated that juglone sensitized melanoma cells to TRAIL‑induced cytotoxicity by MTT and crystal violet assays. Flow cytometry analysis indicated that juglone potentiated TRAIL‑induced cell death. Western blot assay demonstrated that the expressions of cleaved poly(ADP‑ribose) polymerase (PARP) and cleaved caspase 3 were markedly increased in the juglone combined with TRAIL group. Exposure to TRAIL alone did not induce the production of reactive oxygen species (ROS), activation of p38 orincrease of p53 in the TRAIL‑resistant melanoma cells, as determined by flow cytometry and western blot analysis. However, exposure to TRAIL in combination with juglone markedly increased the production of ROS, activated p38 and increased p53, compared with the cells treated with either juglone or TRAIL alone. Pretreatment with N‑acetyl cysteine, a ROS scavenger, significantly reduced the cytotoxicity of juglone in combination with TRAIL, which further supported that ROS was involved in the juglone‑induced sensitization of TRAIL. In conclusion, juglone potentiated TRAIL‑induced apoptosis in melanoma cells, and these effects were partially mediated through the ROS‑p38‑p53 pathway. These findings suggested that juglone may be a potential sensitizer for TRAIL therapy in the treatment of melanoma.

Casticin induced apoptotic cell death and altered associated gene expression in human colon cancer colo 205 cells

Casticin, a polymethoxyflavone, derived from natural plant Fructus Viticis exhibits biological activities including anti-cancer characteristics. The anti-cancer and alter gene expression of casticin on human colon cancer cells and the underlying mechanisms were investigated. Flow cytometric assay was used to measure viable cell, cell cycle and sub-G1 phase, reactive oxygen species (ROS) and Ca²⁺ productions, level of mitochondria membrane potential (ΔΨ_m ) and caspase activity. Western blotting assay was used to detect expression of protein level associated with cell death. Casticin induced cell morphological changes, decreased cell viability and induced G2/M phase arrest in colo 205 cells. Casticin increased ROS production but decreased the levels of ΔΨ_m , and Ca²⁺ , increased caspase-3, -8, and -9 activities. The cDNA microarray indicated that some of the cell cycle associated genes were down-regulated such as cyclin-dependent kinase inhibitor 1A (CDKN1A) (p21, Cip1) and p21 protein (Cdc42/Rac)-activated kinase 3 (PAK3). TNF receptor-associated protein 1 (TRAP1), CREB1 (cAMP responsive element binding protein 1) and cyclin-dependent kinase inhibitor 1B (CDKN1B) (p27, Kip1) genes were increased but matrix metallopeptidase 2 (MMP-2), toll-like receptor 4 (TLR4), PRKAR2B (protein kinase, cAMP-dependent, regulatory, type II, bet), and CaMK4 (calcium/calmodulin-dependent protein kinase IV) genes were inhibited. Results suggest that casticin induced cell apoptosis via the activation of the caspase- and/or mitochondria-dependent signaling cascade, the accumulation of ROS and altered associated gene expressions in colo 205 human colon cancer cells.

Isolation and purification of novel peptides derived from Sepia ink: Effects on apoptosis of prostate cancer cell PC‑3

Novel prostate cancer therapeutics are in high demand. In order to identify potential therapeutic targets, protein from sepia ink was hydrolyzed by utilizing pepsin in an orthogonal array design. Pepsin hydrolysate (SH) obtained at optimal conditions exhibited the highest antitumor activity. Subsequently, a novel antitumor peptide, which was termed SHP, was isolated through ultrafiltration, gel filtration chromatography and reversed phase high‑performance liquid chromatography. The amino acid sequence of SHP was identified as Leu‑Lys‑Glu‑Glu‑Asn‑Arg‑Arg‑Arg‑Arg‑Asp with a molecular mass of 1371.53 Da. The results of the proliferation assay revealed that SHP significantly inhibited the proliferation of PC‑3 cells in a time‑ and dose‑dependent manner. Acridine orange/ethidium bromide staining indicated significant SHP‑induced apoptosis. Furthermore, Annexin V/PI double‑staining assays revealed that the percentage of early‑ stage apoptotic cells increased from 8.85 to 29% following PC‑3 exposure to 5, 10 and 15 mg/ml SHP for 24 h. SHP‑induced apoptosis was accompanied by the activation of cellular tumor antigen p53 and caspase‑3, the upregulation of apoptosis regulator BAX, and the downregulation of apoptosis regulator Bcl‑2. These findings suggest that SHP is a novel inducer of apoptosis in vitro and merits further investigation as a possible therapeutic agent for the treatment of cancer.

Structural and Antioxidant Properties of Compounds Obtained from Fe2+ Chelation by Juglone and Two of Its Derivatives: DFT, QTAIM, and NBO Studies

The chelating ability of juglone and two of its derivatives towards Fe²⁺ion and the antioxidant activity (AOA) of the resulting chelates and complexes (in the presence of H₂O and CH₃OH as ligands) in gas phase is reported via bond dissociation enthalpy, ionization potential, proton dissociation enthalpy, proton affinity, and electron transfer enthalpy. The DFT/B3LYP level of theory associated with the 6-31+G(d,p) and 6-31G(d) Pople-style basis sets on the atoms of the ligands and the central Fe(II), respectively, was used. Negative chelation free energies obtained revealed that juglone derivatives possessing the O-H substituent (L₂) have the greatest ability to chelate Fe²⁺ ion. Apart from 1B, thermodynamic descriptors of the AOA showed that the direct hydrogen atom transfer is the preferred mechanism of the studied molecules. NBO analysis showed that the Fe-ligand bonds are all formed through metal to ligand charge transfer. QTAIM studies revealed that among all the Fe-ligand bonds, the O₁-Fe bond of 1A is purely covalent. The aforementioned results show that the ligands can be used to fight against Fe(II) toxicity, thus preserving human health, and fight against the deterioration of industrial products. In addition, most of the complexes studied have shown a better AOA than their corresponding ligands.

Juglone ameliorates skin wound healing by promoting skin cell migration through Rac1/Cdc42/PAK pathway

Skin cell regeneration and wound healing are key processes in the recovery from skin injuries. Rapid cell migration and regeneration of skin cells lead to faster and better healing of wounded skin. In the present study, we aimed to investigate the wound healing potential of juglone, a naturally occurring Pin1 inhibitor found in walnuts. Cultured skin cells (NHDF and HaCaT) and hairless mice were treated with juglone after wound creation to examine its effects on cell migration and wound healing rate. The expressions of cell migration related proteins (Rac1, Cdc42, and α-PAK), collagen deposition, and angiogenesis were analyzed. Juglone treatment resulted in faster rate of growth and migration and recovered cell morphology, particularly at a concentration of 5 µM, in skin cells compared to the untreated group. In vivo experiments showed that mice treated with juglone showed faster wound healing rate with better skin morphology and collagen deposition than the vehicle group. Furthermore, juglone increased the activation and/or expression of Cdc42, Rac1, and α-pak in HaCaT cells, and resulted in enhanced angiogenesis in endothelial cells (HUVECs). Juglone also activated MAPKs signaling by activation of ERK, JNK, and p38 proteins. Taken together, these data suggest that juglone may be a potential candidate for wound healing and skin regeneration which ameliorates wound healing mainly by promoting skin cell migration through Rac1/Cdc42/PAK pathway.

Phytochemistry, Bioactivity and Potential Impact on Health of Juglans: the Original Plant of Walnut

Walnuts are seeds with a hard shell from the genus Juglans (J. mandshurica, J. regia, J. sinensis, J. cathayensis, J. nigra and J. sigillata). Walnuts can nourish brain cells to improve human memory. Other parts of the plant are also employed as traditional Chinese medicines. Modern research on Juglans species has been mostly focused on the above-mentioned species, the seeds of which are all called walnuts. Juglans species have diverse chemical constituents, including diarylheptanoids, quinones, polyphenols, flavones and terpenes. The diarylheptanoids and quinones have notable antitumor activity, supplying new lead compounds for preparing antitumor drugs. The potent pain-relieving, antioxidant, antibacterial and antitumor activities of these plants are significant. In the review, comprehensive information on the nutritional characteristics, traditional functions, chemical constituents, and biological activities of the Juglans species, together with the seeds used as walnuts is provided to explore their potential and to advance research.

Casticin Induced Apoptosis in A375.S2 Human Melanoma Cells through the Inhibition of NF-[Formula: see text]B and Mitochondria-Dependent Pathways In Vitro and Inhibited Human Melanoma Xenografts in a Mouse Model In Vivo

Casticin, a polymethoxyflavone occurring in natural plants, has been shown to have anticancer activities. In the present study, we aims to investigate the anti-skin cancer activity of casticin on melanoma cells in vitro and the antitumor effect of casticin on human melanoma xenografts in nu/nu mice in vivo. A flow cytometric assay was performed to detect expression of viable cells, cell cycles, reactive oxygen species production, levels of [Formula: see text] and caspase activity. A Western blotting assay and confocal laser microscope examination were performed to detect expression of protein levels. In the in vitro studies, we found that casticin induced morphological cell changes and DNA condensation and damage, decreased the total viable cells, and induced G2/M phase arrest. Casticin promoted reactive oxygen species (ROS) production, decreased the level of [Formula: see text], and promoted caspase-3 activities in A375.S2 cells. The induced G2/M phase arrest indicated by the Western blotting assay showed that casticin promoted the expression of p53, p21 and CHK-1 proteins and inhibited the protein levels of Cdc25c, CDK-1, Cyclin A and B. The casticin-induced apoptosis indicated that casticin promoted pro-apoptotic proteins but inhibited anti-apoptotic proteins. These findings also were confirmed by the fact that casticin promoted the release of AIF and Endo G from mitochondria to cytosol. An electrophoretic mobility shift assay (EMSA) assay showed that casticin inhibited the NF-[Formula: see text]B binding DNA and that these effects were time-dependent. In the in vivo studies, results from immuno-deficient nu/nu mice bearing the A375.S2 tumor xenograft indicated that casticin significantly suppressed tumor growth based on tumor size and weight decreases. Early G2/M arrest and mitochondria-dependent signaling contributed to the apoptotic A375.S2 cell demise induced by casticin. In in vivo experiments, A375.S2 also efficaciously suppressed tumor volume in a xenotransplantation model. Therefore, casticin might be a potential therapeutic agent for the treatment of skin cancer in the future.

Juglanthraquinone C Induces Intracellular ROS Increase and Apoptosis by Activating the Akt/Foxo Signal Pathway in HCC Cells

Juglanthraquinone C (JC), a naturally occurring anthraquinone extracted from Juglans mandshurica, could induce apoptosis of cancer cells. This study aims to investigate the detailed cytotoxicity mechanism of JC in HepG2 and BEL-7402 cells. The Affymetrix HG-U133 Plus 2.0 arrays were first used to analyze the mRNA expression exposed to JC or DMSO in HepG2 cells. Consistent with the previous results, the data indicated that JC could induce apoptosis and hyperactivated Akt. The Western blot analysis further revealed that Akt, a well-known survival protein, was strongly activated in HepG2 and BEL-7402 cells. Furthermore, an obvious inhibitory effect on JC-induced apoptosis was observed when the Akt levels were decreased, while the overexpression of constitutively active mutant Akt greatly accelerated JC-induced apoptosis. The subsequent results suggested that JC treatment suppressed nuclear localization and increased phosphorylated levels of Foxo3a, and the overexpression of Foxo3a abrogated JC-induced apoptosis. Most importantly, the inactivation of Foxo3a induced by JC further led to an increase of intracellular ROS levels by suppressing ROS scavenging enzymes, and the antioxidant N-acetyl-L-cysteine and catalase successfully decreased JC-induced apoptosis. Collectively, this study demonstrated that JC induced the apoptosis of hepatocellular carcinoma (HCC) cells by activating Akt/Foxo signaling pathway and increasing intracellular ROS levels.

Augmentation of oxidative stress-induced apoptosis in MCF7 cells by ascorbate-tamoxifen and/or ascorbate-juglone treatments

Since reactive oxygen species (ROS) play diverse roles in cancer, modulating the redox status of cancerous cells seems to be a promising therapeutic approach. Oxidant-targeted therapy appears logical for intervention with the acquired adaptive response to oxidative stress in cancer. In this study, we investigated the cytotoxic effects of juglone (J) and tamoxifen (T) and also the combination of each with ascorbate (A): tamoxifen/ascorbate (TA) and/or juglone/ascorbate (JA) on MCF7 cancerous cells. The results revealed that the growth inhibitory effects of juglone and tamoxifen were each associated with enhanced levels of ROS production and lipid peroxidation. These effects were markedly intensified in tamoxifen/ascorbate and juglone/ascorbate co-treatments. On the other hand, the intracellular anti-oxidant components such as reduced glutathione (GSH), catalase, superoxide dismutase (SOD), and glutathione peroxidase significantly declined in cells subjected to combination treatments compared to that in cells exposed solely to tamoxifen, juglone, and the untreated control cells. In addition, ascorbate association induced more apoptotic and necrotic or necrotic-like cell death than cells treated with each drug alone. These results were further confirmed by comparing the Bax/Bcl2 ratio in combination-treated cells. Additionally, ascorbate was able to potentiate the cytotoxic effects of combination therapy via activation of ROS-responsive factors including Foxo family members.