Curcumin I Mediates Neuroprotective Effect Through Attenuation of Quinoprotein Formation,p‐p38 MAPK Expression,and Caspase‐3 Activation in 6‐Hydroxydopamine Treated SH‐SY5Y Cells

6‐Hydroxydopamine (6‐OHDA) selectively enters dopaminergic neurons and undergoes auto‐oxidation resulting in the generation of reactive oxygen species and dopamine quinones, subsequently leading to apoptosis. This mechanism mimics the pathogenesis of Parkinson's disease and has been used to induce experimental Parkinsonism in both in vitro and in vivo systems. In this study, we investigated the effects of curcumin I (diferuloylmethane) purified from Curcuma longa on quinoprotein production, phosphorylation of p38 MAPK (p‐p38), and caspase‐3 activation in 6‐OHDA‐treated SH‐SY5Y dopaminergic cells. Pretreatment of SH‐SY5Y with curcumin I at concentrations of 1, 5, 10, and 20 μM, significantly decreased the formation of quinoprotein and reduced the levels of p‐p38 and cleaved caspase‐3 in a dose‐dependent manner. Moreover, the levels of the dopaminergic neuron marker, phospho‐tyrosine hydroxylase (p‐TH), were also dose‐dependently increased upon treatment with curcumin I. Our results clearly demonstrated that curcumin I protects neurons against oxidative damage, as shown by attenuation of p‐p38 expression, caspase‐3‐activation, and toxic quinoprotein formation, together with the restoration of p‐TH levels. This study provides evidence for the therapeutic potential of curcumin I in the chemoprevention of oxidative stress‐related neurodegeneration. Copyright © 2013 John Wiley & Sons, Ltd.     

Protective effects of 3′‐deoxy‐4‐O‐methylepisappanol from Caesalpinia sappan against glutamate‐induced neurotoxicity in primary cultured rat cortical cells

To examine the neuroprotective effects of Caesalpinia sappan L., we tested its protection against the glutamate‐induced neurotoxicity in primary cortical cultured neurons. We found that an aqueous extract of this medicinal plant exhibited significant protection against glutamate‐induced toxicity in primary cultured rat cortical cells. In order to clarify the neuroprotective mechanism(s) of this observed effect, isolation was performed to seek and identify active fractions and components. By such fractionation, two known compounds – sappanchalcone and 3′‐deoxy‐4‐O‐methylepisappanol – were isolated from the methanol extracts from the air‐dried and chipped C. sappan. Among these two compounds, 3′‐deoxy‐4‐O‐methylepisappanol exhibited significant neuroprotective activities against glutamate‐induced toxicity, exhibiting cell viability of about 50%, at concentrations ranging from 0.1 μM to 10 μM. Therefore, the neuroprotective effect of C. sappan might be due to the inhibition of glutamate‐induced toxicity by the protosappanin derivative it contains. Copyright © 2009 John Wiley & Sons, Ltd.     

Phloroglucinol Protects INS‐1 Pancreatic β‐cells Against Glucotoxicity‐Induced Apoptosis

Decreasing numbers, and impaired function, of pancreatic β‐cells are key factors in the development of type 2 diabetes. This study was designed to investigate whether phloroglucinol protected pancreatic β‐cells against glucotoxicity‐induced apoptosis using a rat insulinoma cell line (INS‐1). High glucose treatment (30 mM) induced INS‐1 cell death; however, the level of glucose‐induced apoptosis was significantly reduced in cells treated with 100‐μM phloroglucinol. Treatment with 10–100‐μM phloroglucinol increased cell viability and decreased intracellular levels of reactive oxygen species, nitric oxide, and lipid peroxidation dose‐dependently in INS‐1 cells pretreated with high glucose. Furthermore, phloroglucinol treatment markedly reduced the protein expression of Bax, cytochrome c, and caspase 9, while increasing anti‐apoptotic Bcl‐2 protein expression. Cell death type was examined using annexin V/propidium iodide staining, revealing that phloroglucinol markedly reduced high glucose‐induced apoptosis. These results demonstrated that phloroglucinol could be useful as a potential therapeutic agent for the protection of pancreatic β‐cells against glucose‐induced apoptosis. Copyright © 2015 John Wiley & Sons, Ltd.     

Apoptosis Induction by 13‐Acetoxyrolandrolide through the Mitochondrial Intrinsic Pathway

The aim of this study was to evaluate the mechanisms of cytotoxicity of the sesquiterpene lactone 13‐acetoxyrolandrolide, a nuclear factor kappa B (NF‐κB) inhibitor that was previously isolated from Rolandra fruticosa. The effects associated with the inhibition of the NF‐κB pathway included dose‐dependent inhibition of the NF‐κB subunit p65 (RelA) and inhibition of upstream mediators IKKβ and oncogenic Kirsten rat sarcoma (K‐Ras). The inhibitory concentration of 13‐acetoxyrolandrolide on K‐Ras was 7.7 µm . The downstream effects of the inhibition of NF‐κB activation were also investigated in vitro. After 24 h of treatment with 13‐acetoxyrolandrolide, the mitochondrial transmembrane potential was depolarized in human colon cancer (HT‐29) cells. The mitochondrial oxidative phosphorylation was also negatively affected, and reduced levels of nicotinamine adenine dinucleotide phosphate (NAD(P)H) were detected after 2 h of 13‐acetoxyrolandrolide exposure. Furthermore, the expression of the pro‐apoptotic protein caspase‐3 increased in a concentration‐dependent manner. Cell flow cytometry showed that 13‐acetoxyrolandrolide induced cell cycle arrest at G₁, indicating that the treated cells had undergone caspase‐3‐mediated apoptosis, indicating negative effects on cancer cell proliferation. These results suggest that 13‐acetoxyrolandrolide inhibits NF‐κB and K‐Ras and promotes cell death mediated through the mitochondrial apoptotic pathway. Copyright © 2013 John Wiley & Sons, Ltd.     

Ferulate Protects the Epithelial Barrier by Maintaining Tight Junction Protein Expression and Preventing Apoptosis in Tert‐Butyl Hydroperoxide‐Induced Caco‐2 Cells

Epithelial barrier function is determined by both transcellular and paracellular permeability, the latter of which is mainly influenced by tight junctions (TJs) and apoptotic leaks within the epithelium. We investigated the protective effects of ferulate on epithelial barrier integrity by examining permeability, TJ protein expression, and apoptosis in Caco‐2 cells treated with tert‐butyl hydroperoxide (t‐BHP), a strong reactive species inducer. Caco‐2 cells pretreated with ferulate (5 or 15 μM) were exposed to t‐BHP (100 μM), and ferulate suppressed the t‐BHP‐mediated increases in reactive species and epithelial permeability in Caco‐2 cells. Moreover, ferulate inhibited epithelial cell leakage induced by t‐BHP, which was accompanied by decreased expression of the TJ proteins zonula occludens‐1 and occludin. In addition, pretreatment with ferulate markedly protected cells against t‐BHP‐induced apoptosis, as evidenced by decreased nuclear condensation, cytochrome c release, and caspase‐3 cleavage and an increased Bax/Bcl‐2 ratio. These results suggest that ferulate protects the epithelial barrier of Caco‐2 cells against oxidative stress, which results in increased epithelial permeability, decreased TJ protein expression, and increased apoptosis. The most significant finding of our study is the demonstration of protective, ferulate‐mediated antioxidant effects on barrier integrity, with a particular focus on intracellular molecular mechanisms. Copyright © 2012 John Wiley & Sons, Ltd.     

THC (Δ9‐Tetrahydrocannabinol) Exerts Neuroprotective Effect in Glutamate‐affected Murine Primary Mesencephalic Cultures Through Restoring Mitochondrial Membrane Potential and Anti‐apoptosis Involving CB1 Receptor‐dependent Mechanism

Aging‐related neurodegenerative diseases, such as Parkinson's disease (PD) or related disorders, are an increasing societal and economic burden worldwide. Δ9‐Tetrahydrocannabinol (THC) is discussed as a neuroprotective agent in several in vitro and in vivo models of brain injury. However, the mechanisms by which THC exhibits neuroprotective properties are not completely understood. In the present study, we investigated neuroprotective mechanisms of THC in glutamate‐induced neurotoxicity in primary murine mesencephalic cultures, as a culture model for PD. Glutamate was administered for 48 h with or without concomitant THC treatment. Immunocytochemistry staining and resazurin assay were used to evaluate cell viability. Furthermore, superoxide levels, caspase‐3 activity, and mitochondrial membrane potential were determined to explore the mode of action of this compound. THC protected dopaminergic neurons and other cell types of primary dissociated cultures from glutamate‐induced neurotoxicity. Moreover, THC significantly counteracted the glutamate‐induced mitochondrial membrane depolarization and apoptosis. SR141716A, a CB₁ receptor antagonist, concentration‐dependently blocked the protective effect of THC in primary mesencephalic cultures. In conclusion, THC exerts anti‐apoptotic and restores mitochondrial membrane potential via a mechanism dependent on CB₁ receptor. It strengthens the fact that THC has a benefit on degenerative cellular processes occurring, among others, in PD and other neurodegenerative diseases by slowing down the progression of neuronal cell death. Copyright © 2016 John Wiley & Sons, Ltd.     

Cytotoxic Activity and Antioxidant Capacity of Purified Lichen Metabolites: An In Vitro Study

The purpose of this study was to investigate the effects of six lichen metabolites (diffractaic acid, lobaric acid, usnic acid, vicanicin, variolaric acid, protolichesterinic acid) on proliferation, viability and reactive oxygen species (ROS) level towards three human cancer cell lines, MCF‐7 (breast adenocarcinoma), HeLa (cervix adenocarcinoma) and HCT‐116 (colon carcinoma). Cells were treated with different concentrations (2.5–100 μM) of these compounds for 48 h. In this comparative study, our lichen metabolites showed various cytotoxic effects in a concentration‐dependent manner, and usnic acid was the most potent cytotoxic agent, while variolaric acid did not inhibit the proliferation of any of the three cell lines used. All tested lichen compounds did not exhibit free radical scavenging activity using the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) assay. The lichen metabolites did not significantly increase the intracellular ROS level and did not prevent oxidative injury induced by t‐butylhydroperoxide in HeLa cells. To better clarify the mechanism(s) of cytotoxic effect induced by protolichesterinic acid in HeLa cells, we investigated apoptotic markers such as condensation and fragmentation of nuclear chromatin and activation of caspase‐3, 8 and 9. Our results revealed that the antiproliferative activity of 40 μM protolichesterinic acid in HeLa cells is related to its ability to induce programmed cell death involving caspase‐3, 8 and 9 activation. Copyright © 2012 John Wiley & Sons, Ltd.     

Protective effects of dibenzocyclooctadiene lignans from Schisandra chinensis against beta‐amyloid and homocysteine neurotoxicity in PC12 cells

Aggregated beta‐amyloid (Aβ) and elevated plasma levels of homocysteine have been implicated as critical factors in the pathogenesis of Alzheimer's disease. The neuroprotective effects and possible mechanism of four structurally similar dibenzocyclooctadiene lignans (namely schisandrin, schisantherin A, schisandrin B and schisandrin C) isolated from the fruit of Schisandra chinensis (Turcz.) Baill. (Schisandraceae) against Aβ_25‐35 and homocysteine toxicity in PC12 cells was studied. Exposure of PC12 cells to 0.5 µm Aβ_25‐35 caused significant cell death, increased the number of apoptotic cells, elevated reactive oxygen species, increased the levels of the pro‐apoptotic protein Bax and caspase‐3 activation. All these effects induced by Aβ_25‐35 were markedly reversed by schisandrin B and schisandrin C pretreatment, while schisandrin and schisantherin A had no obvious effects. Meanwhile, schisandrin B and schisandrin C reversed homocysteine‐induced cytotoxicity. The results indicated that schisandrin B and schisandrin C protected PC12 cells against Aβ toxicity by attenuating ROS production and modulating the apoptotic signal pathway through Bax and caspase‐3. Further structure–activity analysis of Schisandra lignans and evaluations of their neuroprotective effects using AD animal models are warranted. Copyright © 2010 John Wiley & Sons, Ltd.     

6‐Acetoxy Cyperene,a Patchoulane‐type Sesquiterpene Isolated from Cyperus rotundus Rhizomes Induces Caspase‐dependent Apoptosis in Human Ovarian Cancer Cells

Cyperus rotundus (Cyperaceae) has been widely used in traditional medicine for the treatment of various diseases, including cancer. Although an anti‐tumour effect has been suggested for C. rotundus, the anti‐tumour effects and underlying molecular mechanisms of its bioactive compounds are poorly understood. The n‐hexane fraction of an ethanol extract of C. rotundus rhizomes was found to inhibit cell growth in ovarian cancer (A2780, SKOV3 and OVCAR3) and endometrial cancer (Hec1A and Ishikawa) cells. Among the thirteen sesquiterpenes isolated from the n‐hexane fraction, some patchoulane‐type compounds, but not eudesmane‐type compounds, showed moderate cytotoxic activity in human ovarian cancer cells. In particular, the patchoulane sesquiterpene 6‐acetoxy cyperene had the most potent cytotoxicity. In this regard, propidium iodide/Annexin V staining and terminal deoxynucleotidyl transferase dUTP (deoxynucleotide triphosphate) nick end labeling assay were performed to study cell cycle progression and apoptosis. 6‐acetoxy cyperene induced apoptosis, as shown by the accumulation of sub‐G1 and apoptotic cells. Furthermore, treatment with 6‐acetoxy cyperene stimulated the activation of caspase‐3, caspase‐8 and caspase‐9 and poly(ADP‐ribose)polymerase in a dose‐dependent manner. Pretreatment with caspase inhibitors neutralized the pro‐apoptotic activity of 6‐acetoxy cyperene. Taken together, these data suggest that 6‐acetoxy cyperene, a patchoulane‐type sesquiterpene isolated from C. rotundus rhizomes, is an anti‐tumour compound that causes caspase‐dependent apoptosis in ovarian cancer cells. Copyright © 2015 John Wiley & Sons, Ltd.     

The ethyl acetate extract of Phellinus linteus grown on germinated brown rice induces G0/G1 cell cycle arrest and apoptosis in human colon carcinoma HT29 cells

It is well known that Phellinus linteus has a variety of biological functions, such as antitumor and immunomodulating activities. In our previous studies, we developed a P. linteus grown on germinated brown rice (PBR) and found that organic solvent extracts of PBR possessed immunomodulating activity to regulate a balance of cytokine network in mice. The components of PBR are ergosterol peroxide, γ‐aminobutyric acid (GABA) and B‐glucan. In this study, we demonstrate that an organic solvent extract of P. linteus grown on PBR induced apoptotic cell death through the induction of G₀/G₁ arrest of cell cycle and the apoptosis via DNA fragmentation in human colon carcinoma HT‐29 cells. Cell death induced by the extract of P. linteus grown on PBR was shown to be associated with the upregulation of p21^CIP1/WAF1, the downregulation of cyclin D1, anti‐apoptotic protein, Bcl‐2, the release of cytochrome c, and the activation of caspase‐9, caspase‐3 and caspase‐8. This study suggests that the ethyl acetate extract of P. linteus grown on PBR induces apoptosis accompanied by cell cycle arrest at G₀/G₁ phase and regulates apoptosis‐regulatory proteins, which may be applicable to anticancer therapy. Copyright © 2009 John Wiley & Sons, Ltd.     

Apoptosis of BGC823 cell line induced by p‐hydroxymethoxybenzobijuglone,a novel compound from Juglans mandshurica

p‐Hydroxymethoxybenzobijuglone (HMBBJ), a new quinone compound isolated from Juglans mandshurica (by bioassay‐guided fractionation), showed cytotoxic activity in the gastric carcinoma cell line BGC823. The growth of BGC823 cells was inhibited as demonstrated by MTT assay and several cellular characteristic changes, such as cell shrinkage, chromatin condensation and apoptotic body formation with programmed cell death. Flow cytometry analysis revealed that the BGC823 cell cycle was arrested at G2/M phase by HMBBJ, and the apoptotic rate of BGC823 cells increased with respect to HMBBJ in a dose‐dependent manner. HMBBJ also activated caspase‐3, decreased the expression of Bcl‐2 and caused a decrease in the mitochondrial membrane potential (ΔΨ_m). These findings suggest that HMBBJ could significantly induce apoptosis in BGC823 cells and should be considered as a potential candidate for a chemotherapeutic drug against cancer. Copyright © 2008 John Wiley & Sons, Ltd.     

Inhibitory effects of the aqueous extract of Magnolia officinalis on the responses of human urinary bladder cancer 5637 cells in vitro and mouse urinary bladder tumors induced by N‐Butyl‐N‐(4‐hydroxybutyl) nitrosamine in vivo

This study investigated the anticancer activity of Magnolia officinalis on urinary bladder cancer in vitro and in vivo, and elucidated the mechanism of its activity. An aqueous extract of M. officinalis inhibited cell viability and DNA synthesis in cultured human urinary bladder cancer 5637 cells. Inhibition of proliferation was the result of apoptotic induction, because FACS analyses of 5637 cells treated with M. officinalis showed a sub‐G1 phase accumulation. M. officinalis extract also increased cytoplasmic DNA–histone complex dose‐dependently. These inhibitory effects were associated with the upregulation of proapoptotic molecules Bax, cytochrome c and caspase 3. Treatment of 5637 cells with M. officinalis extract suppressed the expression of matrix metalloproteinase 2 (MMP‐2) and MMP‐9, as revealed by zymographic and immunoblot analyses. When M. officinalis extract was given to mice simultaneously with the carcinogen N‐butyl‐N‐(4‐hydroxybutyl) nitrosamine, which induces urinary bladder tumors, the size of the induced tumors was smaller. Finally, histological data indicated that the histological grade of carcinoma and the depth of invasion were dramatically decreased by treatment with M. officinalis extract in mice with N‐butyl‐N‐(4‐hydroxybutyl) nitrosamine‐induced urinary bladder tumors. In conclusion, the findings showed that M. officinalis extract exhibited potential chemopreventive activity against urinary bladder tumor in vitro and in vivo. Copyright © 2008 John Wiley & Sons, Ltd.     

7,3′‐dimethoxy hesperetin induces apoptosis of fibroblast‐like synoviocytes in rats with adjuvant arthritis through caspase 3 activation

Approaches inducing fibroblast‐like synoviocytes (FLS) apoptosis in rheumatoid arthritis (RA) patients have been considered as a promising strategy for treating RA. Here, adjuvant arthritis (AA) in rat was induced by complete Freund's adjuvant and FLS were separated and cultured using a tissue explant cultivation method. The apoptotic effect of 7,3′‐dimethoxy hesperetin (DMHP, a highly antirheumatic active derivative of hesperidin) on AA FLS was evaluated with MTT assay, Hoechst staining and flow cytometry analysis. Bcl‐2, Bax, caspase 3 gene expressions and caspase 3 activity were assayed to identify whether caspase 3 was involved in the apoptosis induced by DMHP. It was found that DMHP significantly decreased AA FLS proliferation in vitro by MTT assay. The AA FLS treated with DMHP displayed typical apoptotic characteristics including irregularity in shape, nuclear shrinkage and chromatin condensation. Flow cytometry analysis indicated that DMHP could obviously increase the AA FLS apoptosis rate. Compared with the AA‐FLS control group, DMHP markedly decreased the mRNA expression of Bcl‐2, whereas those of Bax and caspase 3 were increased. Moreover, DMHP significantly increased caspase 3 activity in a dose‐dependent manner. In aggregate, the results demonstrate that DMHP effectively induces AA FLS apoptosis through caspase 3 activation and can be considered as a possible antirheumatic agent. Copyright © 2010 John Wiley & Sons, Ltd.     

Anti‐platelet Activity of Erythro‐(7S,8R)‐7‐acetoxy‐3,4,3′,5′‐tetramethoxy‐8‐O‐4′‐neolignan from Myristica fragrans

Platelets play a critical role in pathogenesis of cardiovascular disorders and strokes. The inhibition of platelet function is beneficial for the treatment and prevention of these diseases. In this study, we investigated the anti‐platelet activity of erythro‐(7S,8R)‐7‐acetoxy‐3,4,3′,5′‐tetramethoxy‐8‐O‐4′‐neolignan (EATN), a neolignan isolated from Myristica fragrans, using human platelets. EATN preferentially inhibited thrombin‐ and platelet‐activating factor (PAF)‐induced platelet aggregation without affecting platelet damage in a concentration‐dependent manner with IC₅₀ values of 3.2 ± 0.4 and 3.4 ± 0.3 μM, respectively. However, much higher concentrations of EATN were required to inhibit platelet aggregation induced by arachidonic acid. EATN also inhibited thrombin‐induced serotonin and ATP release, and thromboxane B₂ formation in human platelets. Moreover, EATN caused an increase in cyclic AMP (cAMP) levels and attenuated intracellular Ca²⁺ mobilization in thrombin‐activated human platelets. Therefore, we conclude that the inhibitory mechanism of EATN on platelet aggregation may increase cAMP levels and subsequently inhibit intracellular Ca²⁺ mobilization by interfering with a common signaling pathway rather than by directly inhibiting the binding of thrombin or PAF to their receptors. This is the first report of the anti‐platelet activity of EATN isolated from M. fragrans. Copyright © 2013 John Wiley & Sons, Ltd.     

3‐O‐Acetyloleanolic Acid Induces Apoptosis in Human Colon Carcinoma Hct‐116 Cells

The cytotoxic effect of 3‐O‐acetyloleanolic acid, an oleanolic acid derivative isolated from the seeds of Vigna sinensis K., was investigated in human colon carcinoma HCT‐116 cells. 3‐O‐acetyloleanolic acid dose‐dependently inhibited the viability of HCT‐116 cells. Apoptosis was characterized by detection of cell surface annexin V and sub‐G1 apoptotic cell populations. The number of immunostained cells with annexin V‐FITC was increased after treatment with 3‐O‐acetyloleanolic acid. The sub‐G1 cell population was also increased. Expression of TRAIL‐mediated apoptosis signaling‐related death receptor DR5 was increased in 3‐O‐acetyloleanolic acid‐treated HCT‐116 cells. Activation of caspase‐8 and caspase‐3, critical mediators of extrinsic apoptosis signaling, was also increased by 3‐O‐acetyloleanolic acid. The results indicate that 3‐O‐acetyloleanolic acid induces apoptosis in HCT‐116 cells mediated by an extrinsic apoptosis signaling cascade via up‐regulation of DR5. Copyright © 2012 John Wiley & Sons, Ltd.     

Inhibitory effect of n-butylidenephthalide on neointimal hyperplasia in balloon injured rat carotid artery

This investigation was designed to determine the inhibitory effects and mechanisms of n‐butylidenephthalide (BP) from Angelica sinensis on smooth muscle cell (SMC) proliferation in vitro and in balloon injured rat carotid artery. Treatment of cultured rat aorta SMC‐derived A7r5 cells with 25–100 μg/mL BP significantly inhibited the proliferation and arrested the cell cycle in G₀/G₁ phase. BP induced the expression and migration of Nur77 from the nucleus to the cytoplasm. Among signal pathways, JNK and p38 MAPK were phosphorylated after BP treatment. In vivo, the neointimal area of common carotid artery 2 weeks after balloon injury reduced significantly in Sprague‐Dawley rats treated with 150–300 mg/kg BP compared with the control. The proliferative activity indicated by immunohistochemical detection of Ki‐67 positive cells in the neointima was significantly decreased in the 60–300 mg/kg BP treatment groups. The apoptotic activity indicated by cleaved caspase‐3 positive cells and Nur77 positive cells in the neointima was significantly increased in rats treated with 60–300 mg/kg BP. This study demonstrated BP inhibited neointimal hyperplasia in balloon injured rat carotid artery due to its dual effects of proliferative inhibition and apoptotic induction on SMCs. Up‐regulation of Nur77 gene may partly explain the antihyperplasia activity of BP on the neointima. Copyright © 2011 John Wiley & Sons, Ltd.     

Aloe‐emodin Induces Apoptosis in Human Liver HL‐7702 Cells through Fas Death Pathway and the Mitochondrial Pathway by Generating Reactive Oxygen Species

Aloe‐emodin (1,8‐dihydroxy‐3‐hydroxymethyl‐anthraquinone) is one of the primary active compounds in total rhubarb anthraquinones isolated from some traditional medicinal plants such as Rheum palmatum L. and Cassia occidentalis, which induce hepatotoxicity in rats. Thus, the aim of this study was to determine the potential cytotoxic effects and the underlying mechanism of aloe‐emodin on human normal liver HL‐7702 cells. The CCK‐8 assays demonstrated that aloe‐emodin decreased the viability of HL‐7702 cells in a dose‐dependent and time‐dependent manner. Aloe‐emodin induced S and G2/M phase cell cycle arrest in HL‐7702 cells. This apoptosis was further investigated by flow cytometry and nuclear morphological changes by DAPI staining, respectively. Moreover, aloe‐emodin provoked the production of intracellular reactive oxygen species and the depolarization of mitochondrial membrane potential (MMP). Further studies by western blot indicated that aloe‐emodin dose‐dependently up‐regulated the levels of Fas, p53, p21, Bax/Bcl‐2 ratio, and cleaved caspase‐3, ‐8, ‐9, and subsequent cleavage of poly(ADP‐ribose)polymerase (PARP). Taken together, these results suggest that aloe‐emodin inhibits cell proliferation of HL‐7702 cells and induces cell cycle arrest and caspase‐dependent apoptosis via both Fas death pathway and the mitochondrial pathway by generating reactive oxygen species, indicating that aloe‐emodin should be taken into account in the risk assessment for human exposure. Copyright © 2017 John Wiley & Sons, Ltd.     

Rutin attenuates vancomycin‐induced renal tubular cell apoptosis via suppression of apoptosis,mitochondrial dysfunction,and oxidative stress

Vancomycin is a glycopeptide antibiotic widely used to treat infections caused by methicillin‐resistant Staphylococcus aureus. However, nephrotoxicity is a major adverse side effect, and the development of effective nephroprotective agents remains a priority in antimicrobial chemotherapy. In this study, we investigated the cell protective effects of the flavonol glycoside rutin against vancomycin‐induced toxicity. Vancomycin added to porcine renal tubular LLC‐PK1 cells caused an increase of production of intracellular reactive oxygen species and subsequent apoptotic cell death. Pretreatment of LLC‐PK1 cells with rutin at 5, 10, and 20 μM for 2 hr prior to 2‐mM vancomycin exposure for 24 hr significantly decreased intracellular reactive oxygen species and increased superoxide dismutase and catalase activities. Rutin pretreatment also protected cells from vancomycin‐induced caspase activation, mitochondrial membrane depolarization, and subsequent apoptosis. This study demonstrates a protective effect of rutin and suggests that rutin coadministration is an alternative therapy for treatment of vancomycin‐induced nephrotoxicity.