Protective effect of EX-527 against high-fat diet-induced diabetic nephropathy in Zucker rats.

High-fat diet (HFD)-induced obesity is implicated in diabetic nephropathy (DN). EX-527, a selective Sirtuin 1 (SIRT1) inhibitor, has multiple biological functions; however, its protective effect against DN is yet to be properly understood. This study was aimed to explore the protective effect of EX-527 against DN in HFD-induced diabetic Zucker (ZDF) rats. After 21 weeks of continually feeding HFD to the rats, the apparent characteristics of progressive DN were observed, which included an increase in kidney weight (~160%), hyperglycemia, oxidative stress, and inflammatory cytokines, and subsequent renal cell damage. However, the administration of EX-527 for 10 weeks significantly reduced the blood glucose concentration and kidney weight (~59%). Furthermore, EX-527 significantly reduced the serum concentration of transforming growth factor-ß1 (49%), interleukin (IL)-1ß (52%), and IL-6 in the HFD-fed rats. Overall, the antioxidant activities significantly increased, and oxidative damage to lipids or DNA was suppressed. Particularly, EX-527 significantly reduced blood urea nitrogen (81%), serum creatinine (71%), microalbumin (43%), and urinary excretion of protein-based biomarkers. Histopathological examination revealed expansion of the extracellular mesangial matrix and suppression of glomerulosclerosis following EX-527 administration. EX-527 downregulated the expression of α-SMA (~64%), TGF-ß (25%), vimentin, α-tubulin, fibronectin, and collagen-1 in the kidneys of the HFD-fed rats. Additionally, EX-527 substantially reduced claudin-1 and SIRT1 expression, but increased the expression of SIRT3 in the kidneys of the HFD-fed rats. EX-527 also inhibited the growth factor receptors, including EGFR, PDGFR-ß, and STAT3, which are responsible for the anti-fibrotic effect of SIRT-1. Therefore, the administration of EX-527 protects against HFD-induced DN.

Knockdown of Pyruvate Kinase M2 Inhibits Cell Proliferation, Metabolism, and Migration in Renal Cell Carcinoma.

Emerging evidence indicates that the activity of pyruvate kinase M2 (PKM2) isoform is crucial for the survival of tumor cells. However, the molecular mechanism underlying the function of PKM2 in renal cancer is undetermined. Here, we reveal the overexpression of PKM2 in the proximal tubule of renal tumor tissues from 70 cases of patients with renal carcinoma. The functional role of PKM2 in human renal cancer cells following small-interfering RNA-mediated PKM2 knockdown, which retarded 786-O cell growth was examined. Targeting PKM2 affected the protein kinase B (AKT)/mechanistic target of the rapamycin 1 (mTOR) pathway, and downregulated the expression of glycolytic enzymes, including lactate dehydrogenase A and glucose transporter-1, and other downstream signaling key proteins. PKM2 knockdown changed glycolytic metabolism, mitochondrial function, adenosine triphosphate (ATP) level, and intracellular metabolite formation and significantly reduced 786-O cell migration and invasion. Acridine orange and monodansylcadaverine staining, immunocytochemistry, and immunoblotting analyses revealed the induction of autophagy in renal cancer cells following PKM2 knockdown. This is the first study to indicate PKM2/AKT/mTOR as an important regulatory axis mediating the changes in the metabolism of renal cancer cells.

Curcumin Ameliorates Benzo[a]pyrene-Induced DNA Damages in Stomach Tissues of Sprague-Dawley Rats.

Benzo[a]pyrene (BaP) is a well-known carcinogen formed during the cooking process. Although BaP exposure has been implicated as one of the risk factors for lung cancer in animals and humans, there are only limited data on BaP-induced gastrointestinal cancer. Therefore, this study investigated the protective effects of curcumin on BaP-induced DNA damage in rat stomach tissues. BaP (20 mg/kg/day) and curcumin (50, 100, or 200 mg/kg) were administered daily to Sprague-Dawley rats by oral gavage over 30 days. Curcumin was pre-administered before BaP exposure. All rats were euthanized, and liver, kidney, and stomach tissues were removed at 24 h after the last treatment. We observed that aspartate aminotransferase (AST), alanine aminotransferase (ALT), and glucose levels were significantly reduced in rats treated with high dose co-administration of curcumin (200 mg/kg) compared to BaP alone. The expression levels of cytochrome P450 (CYP) 1A1 and CYP1B1 were significantly increased in the liver of rats treated with BaP. However, co-administration of curcumin (200 mg/kg) with BaP markedly reduced CYP1A1 expression in a dose-dependent manner. Furthermore, plasma levels of BaP-diolepoxide (BPDE) and BaP metabolites were significantly reduced by co-administration of curcumin (200 mg/kg). Additionally, co-administration of curcumin (200 mg/kg) with BaP significantly reduced the formation of BPDE-I-DNA and 8-hydroxydeoxy guanosine (8-OHdG) adducts in the liver, kidney, and stomach tissues. The inhibition of these adduct formations were more prominent in the stomach tissues than in the liver. Overall, our observations suggest that curcumin might inhibit BaP-induced gastrointestinal tumorigenesis and shows promise as a chemopreventive agent.

Estrogen Deficiency Potentiates Thioacetamide-Induced Hepatic Fibrosis in Sprague-Dawley Rats.

Hepatic fibrosis is characterized by persistent deposition of extracellular matrix proteins and occurs in chronic liver diseases. The aim of the present study is to investigate whether estrogen deficiency (ED) potentiates hepatic fibrosis in a thioacetamide (TAA)-treated rat model. Fibrosis was induced via intraperitoneal injection (i.p.) of TAA (150 mg/kg/day) for four weeks in ovariectomized (OVX) female, sham-operated female, or male rats. In TAA-treated OVX rats, the activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and γ-glutamyl transferase (GGT) were significantly increased compared to those in TAA-treated sham-operated OVX rats or TAA-treated male rats. Furthermore, α-smooth muscle actin (α-SMA) expression was significantly increased compared to that in TAA-treated sham-operated rats. This was accompanied by the appearance of fibrosis biomarkers including vimentin, collagen-I, and hydroxyproline, in the liver of TAA-treated OVX rats. In addition, ED markedly reduced total glutathione (GSH) levels, as well as catalase (CAT) and superoxide dismutase (SOD) activity in TAA-treated OVX rats. In contrast, hepatic malondialdehyde (MDA) levels were elevated in TAA-treated OVX rats. Apoptosis significantly increased in TAA-treated OVX rats, as reflected by elevated p53, Bcl-2, and cleaved caspase 3 levels. Significant increases in interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) concentrations were exhibited in TAA-treated OVX rats, and this further aggravated fibrosis through the transforming growth factor-ß (TGF-ß)/Smad pathway. Our data suggest that ED potentiates TAA-induced oxidative damage in the liver, suggesting that ED may enhance the severity of hepatic fibrosis in menopausal women.

Evaluation of subchronic exposure to triclosan on hepatorenal and reproductive toxicities in prepubertal male rats.

Triclosan (TCS), a common antimicrobial ingredient, is present in many consumer products, including soaps, shampoos, and toothpaste. Owing to its widespread use, potential adverse effects on animals and humans may arise from lifetime exposure, but data on chronic prepubertal exposure of TCS are still lacking. The aim of the present study was to investigate the influence of subchronic TCS exposure (0.25, 25, 250, or 750 mg/kg) on target organ toxicity in prepubertal male rats. After daily administration of TCS to rats by oral gavage for 60 d, a significant reduction in body weight and relative weights of liver, kidneys, testes, and adrenal glands was observed in the 750-mg/kg (high dose) group. Serum alanine aminotransferase and aspartate aminotransferase activities as well as levels of blood urea nitrogen, and creatinine were significantly increased at 750 mg/kg TCS. Further, TCS (750 mg/kg) elevated the protein expressions of hepatic CYP2B1, RXR/PPAR, and levels of malondialdehyde. High-dose TCS exposure induced histological changes as evidenced by reduction of Bowman's space, occlusion of the tubular lumen, and degeneration of tubular epithelial cells in the kidney. Tubular necrosis was confirmed as evidenced by a rise in expression of high mobility group box 1 renal protein. Daily sperm production was significantly diminished by high doses of TCS with marked inhibition of androgen receptor protein expression. Our results indicated that subchronic exposure to excessively high concentrations of 750 mg/kg TCS induced hepatorenal and reproductive toxicities in prepubertal male rats; however, the biological relevance of these findings is questionable as these drug levels are not encountered in the environment.

Hepatic damage exacerbates cisplatin-induced acute kidney injury in Sprague-Dawley rats.

The objective of this study was to elucidate the effect of hepatic damage on cisplatin (CDDP)-induced acute kidney injury (AKI). Thioacetamide (TAA, 150 mg/kg), a hepatotoxicant, was intraperitoneally (i.p.) injected to male Sprague-Dawley rats for 3 d prior to CDDP (5 mg/kg, i.p.) injection. All animals were sacrificed 5 d after CDDP treatment, and urine or blood was obtained to measure various parameters. No significant changes in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity were observed after CDDP treatment. However, pretreatment with TAA significantly elevated ALT and AST activity. Serum blood urea nitrogen and creatinine levels significantly increased in CDDP-treated group compared to control. In addition, urinary excretion of novel protein-based biomarkers such as neutrophil gelatinase-associated lipocalin, vascular endothelial growth factor, kidney injury molecule-1, and tissue inhibitor of metalloproteinase-1 rose markedly in the CDDP-treated group. In particular, pretreatment with TAA markedly elevated CDDP-induced urinary excretion of protein-based nephrotoxic biomarkers compared with CDDP alone. Hematoxylin and eosin staining demonstrated that pretreatment with TAA following CDDP injection led to more severe tubular damage and apoptosis in rats compared with CDDP alone. Antioxidant status was significantly reduced in kidneys following pretreatment with TAA prior to CDDP. These findings indicate that liver injury enhanced the vulnerability of kidney to CDDP-induced AKI and this phenomenon may be associated with severe apoptotic damage.

A New Synthetic Histone Deacetylase Inhibitor, MHY2256, Induces Apoptosis and Autophagy Cell Death in Endometrial Cancer Cells via p53 Acetylation.

We previously discovered a novel sirtuin (SIRT) inhibitor, MHY2256, that exerts anticancer activity through p53 acetylation in MCF-7 human breast cancer cells. We investigated the anticancer activity of MHY2256 against hormone-related cancer, an endometrial cancer with a poor prognosis. The IC50 values of MHY2256 were shown to be much lower than those of salermide, a well-known SIRT inhibitor. Furthermore, MHY2256 significantly reduced the protein expression and activities of SIRT1, 2, and 3, with similar effects to salermide. Particularly, MHY2256 markedly inhibited tumor growth in a tumor xenograft mouse model of Ishikawa cancer cells. During the experimental period, there was no significant change in the body weight of mice treated with MHY2256. A detailed analysis of the sensitization mechanisms of Ishikawa cells revealed that late apoptosis was largely increased by MHY2256. Additionally, MHY2256 increased G1 arrest and reduced the number of cell cyclic-related proteins, suggesting that apoptosis by MHY2256 was achieved by cellular arrest. Particularly, p21 was greatly increased by MHY225656, suggesting that cell cycle arrest by p21 is a major factor in MHY2256 sensitization in Ishikawa cells. We also detected a significant increase in acetylated p53, a target protein of SIRT1, in Ishikawa cells after MHY2256 treatment. In a mouse xenograft model, MHY2256 significantly reduced tumor growth and weight without apparent side effects. These results suggest that MHY2256 exerts its anticancer activity through p53 acetylation in endometrial cancer and can be used for targeting hormone-related cancers.

Selenium-binding protein 1: a sensitive urinary biomarker to detect heavy metal-induced nephrotoxicity.

Identifying novel biomarkers to detect nephrotoxicity is clinically important. Here, we attempted to identify new biomarkers for mercury-induced nephrotoxicity and compared their sensitivity to that of traditional biomarkers in animal models. Comparative proteomics analysis was performed in kidney tissues of Sprague-Dawley rats after oral treatment with HgCl2 (0.1, 1, or 5 mg/kg/day) for 21 days. Kidney cortex tissues were analyzed by two-dimensional gel electrophoresis/matrix-assisted laser desorption/ionization, and differentially expressed proteins were identified. The corresponding spots were quantitated by RT-PCR. Selenium-binding protein 1 (SBP1) was found to be the most markedly upregulated protein in the kidney cortex of rats after HgCl2 administration. However, blood urea nitrogen, serum creatinine, and glucose levels increased significantly only in the 1 or 5 mg/kg HgCl2-treated groups. A number of urinary excretion proteins, including kidney injury molecule-1, clusterin, monocyte chemoattractant protein-1, and ß-microglobulin, increased dose-dependently. Histopathological examination revealed severe proximal tubular damage in high-dose (5 mg/kg) HgCl2-exposed groups. In addition, urinary excretion of SBP1 significantly increased in a dose-dependent manner. To confirm the critical role of SBP1 as a biomarker for nephrotoxicity, normal kidney proximal tubular cells were treated with HgCl2, CdCl2, or cisplatin for 24 h. SBP1 levels significantly increased in conditioned media exposed to nephrotoxicants, but decreased in cell lysates. Our investigations suggest that SBP1 may play a critical role in the pathological processes underlying chemical-induced nephrotoxicity. Thus, urinary excretion of SBP1 might be a sensitive and specific biomarker to detect early stages of kidney injury.

Identification of a sensitive urinary biomarker, selenium-binding protein 1, for early detection of acute kidney injury.

Acute kidney injury (AKI) is associated with increased mortality rate in patients but clinically available biomarkers for disease detection are currently not available. Recently, a new biomarker, selenium-binding protein 1 (SBP1), was identified for detection of nephrotoxicity using proteomic analysis. The aim of this study was to assess the sensitivity of urinary SBP1 levels as an early detection of AKI using animal models such as cisplatin or ischemia/reperfusion (I/R). Sprague-Dawley rats were injected with cisplatin (6 mg/kg, once i.p.) and sacrificed at 1, 3, or 5 days after treatment. Ischemia was achieved by bilaterally occluding both kidneys with a microvascular clamp for 45 min and verified visually by a change in tissue color. After post-reperfusion, urine samples were collected at 9, 24, and 48 hr intervals. Urinary excretion of protein-based biomarkers was measured by Western blot analysis. In cisplatin-treated rats, mild histopathologic alterations were noted at day 1 which became severe at day 3. Blood urea nitrogen (BUN) and serum creatinine (SCr) levels were significantly increased at day 3. Levels of urinary excretion of SBP1, neutrophil gelatinase-associated lipocalin (NGAL), and a tissue inhibitor of metalloproteinase-1 (TIMP-1) were markedly elevated at day 3 and 5 following drug treatment. In the vehicle-treated I/R group, serum levels of BUN and SCr and AST activity were significantly increased compared to sham. Urinary excretion of SBP1 and NGAL rose markedly following I/R. The urinary levels of SBP1, NGAL, TIMP-1, and KIM-1 proteins excreted by AKI patients and normal subjects were compared. Among these proteins, a marked rise in SBP1 was observed in urine of patients with AKI compared to normal subjects. Based upon receiver-operator curves (ROC), SBP1 displayed a higher area under the curve (AUC) scores than levels of SCr, BUN, total protein, and glucose. In particular, SBP1 protein was readily detected in small amounts of urine without purification. Data thus indicate that urinary excretion of SBP1 may be useful as a reliable biomarker for early diagnosis of AKI in patients.

Evaluation of cadmium-induced nephrotoxicity using urinary metabolomic profiles in sprague-dawley male rats.

The aim of this study was to investigate urinary metabolomic profiles associated with cadmium (Cd)-induced nephrotoxicity and their potential mechanisms. Metabolomic profiles were measured by high-resolution (1)H-nuclear magnetic resonance (NMR) spectroscopy in the urine of rats after oral exposure to CdCl2 (1, 5, or 25 mg/kg) for 6 wk. The spectral data were further analyzed by a multivariate analysis to identify specific urinary metabolites. Urinary excretion levels of protein biomarkers were also measured and CdCl2 accumulated dose-dependently in the kidney. High-dose (25 mg/kg) CdCl2 exposure significantly increased serum blood urea nitrogen (BUN), but serum creatinine (sCr) levels were unchanged. High-dose CdCl2 (25 mg/kg) exposure also significantly elevated protein-based urinary biomarkers including osteopontin, monocyte chemoattractant protein-1 (MCP-1), kidney injury molecules-1 (Kim-1), and selenium-binding protein 1 (SBP1) in rat urine. Under these conditions, six urinary metabolites (citrate, serine, 3-hydroxyisovalerate, 4-hydroxyphenyllactate, dimethylamine, and betaine) were involved in mitochondrial energy metabolism. In addition, a few number of amino acids such as glycine, glutamate, tyrosine, proline, or phenylalanine and carbohydrate (glucose) were altered in urine after CdCl2 exposure. In particular, the metabolites involved in the glutathione biosynthesis pathway, including cysteine, serine, methionine, and glutamate, were markedly decreased compared to the control. Thus, these metabolites are potential biomarkers for detection of Cd-induced nephrotoxicity. Our results further indicate that redox metabolomics pathways may be associated with Cd-mediated chronic kidney injury. These findings provide a biochemical pathway for better understanding of cellular mechanism underlying Cd-induced renal injury in humans.

Development of a new broad-spectrum microencapsulation-based spray drying formulation of Bacillus thuringiensis subsp. kurstaki IMBL-B9 for the control of moths.

Certain Bacillus thuringiensis (Bt) strains such as Bt subsp. kurstaki and Bt subsp. aizawai have been widely used for pest management in agricultural practices. However, each strain only shows high specificity for pest control against a narrow range of lepidopteran species, and numerous lepidopteran pests have developed resistance to commercialized Bt strains. Therefore, there is a need for the development of novel Bt bioinsecticides which allow for potent and broad-spectrum insecticidal activity against lepidopteran species, including Spodoptera spp. (Noctuidae) and Plutella xylostealla (Plutellidae). In order to develop a novel bioinsecticide using Bt subsp. kurstaki IMBL-B9 (Btk IMBL-B9) that exhibits excellent insecticidal activity against three different lepidopteran species, we have developed a viable microencapsulation-based spray drying Btk IMBL-B9 formulation. The spore-crystal complex of Btk IMBL-B9 was microencapsulated using coating materials such as gum arabic, maltodextrin, and corn starch via spray drying. The encapsulated formulation of Btk IMBL-B9 presented an increased survival rate and storage stability at 54 ± 2°C for up to 6 weeks. The formulation showed similar insecticidal activity as the commercial bioinsecticide XenTari® against P. xylostella. Under controlled greenhouse conditions, the Btk IMBL-B9 formulation was more effective against Lepidoptera spp. S. frugiperda and P. xylostella, than XenTari®. These results suggest that the microencapsulation-based spray drying formulation of Btk IMBL-B9 can be used effectively for the control of a wide range of moths.

Exogenous Bio-Based 2,3-Butanediols Enhanced Abiotic Stress Tolerance of Tomato and Turfgrass under Drought or Chilling Stress.

Among abiotic stresses in plants, drought and chilling stresses reduce the supply of moisture to plant tissues, inhibit photosynthesis, and severely reduce plant growth and yield. Thus, the application of water stress-tolerant agents can be a useful strategy to maintain plant growth under abiotic stresses. This study assessed the effect of exogenous bio-based 2,3-butanediol (BDO) application on drought and chilling response in tomato and turfgrass, and expression levels of several plant signaling pathway-related gene transcripts. Bio-based 2,3-BDOs were formulated to levo-2,3-BDO 0.9% soluble concentrate (levo 0.9% SL) and meso-2,3-BDO 9% SL (meso 9% SL). Under drought and chilling stress conditions, the application of levo 0.9% SL in creeping bentgrass and meso 9% SL in tomato plants significantly reduced the deleterious effects of abiotic stresses. Interestingly, pretreatment with levo-2,3-BDO in creeping bentgrass and meso-2,3-BDO in tomato plants enhanced JA and SA signaling pathway-related gene transcript expression levels in different ways. In addition, all tomato plants treated with acibenzolar-S-methyl (as a positive control) withered completely under chilling stress, whereas 2,3-BDO-treated tomato plants exhibited excellent cold tolerance. According to our findings, bio-based 2,3-BDO isomers as sustainable water stress-tolerant agents, levo- and meso-2,3-BDOs, could enhance tolerance to drought and/or chilling stresses in various plants through somewhat different molecular activities without any side effects.

Aromatic radiofluorination and biological evaluation of 2-aryl-6-[18F]fluorobenzothiazoles as a potential positron emission tomography imaging probe for ß-amyloid plaques.

To develop agents for radionuclide imaging Aß plaques in vivo, we prepared three fluorine-substituted analogs of arylbenzothiazole class; compound 2 has a high affinity for Aß (K(i)=5.5nM) and the specific binding to Aß in fluorescent staining. In preparation for the synthesis of these arylbenzothiazole analogs in radiolabeled form as an Aß plaques-specific positron emission tomography (PET) imaging probe, we investigated synthetic route suitable for its labeling with the short-lived PET radionuclide fluorine-18 (t(1/2)=110min) and diaryliodonium tosylate precursors (12, 13a-e and 14). 2-Aryl-6-[(18)F]fluorobenzothiazoles ([(18)F]1-3) were synthesized in efficiently short reaction times (40-60min) with high radiochemical yields (19-40%), purities (>95%) and specific activities (85-118GBq/µmol). Tissue distribution studies showed that high radioactivity of [(18)F]2 accumulated in the brain with rapid clearance in healthy mice. Radioactive metabolites were analyzed in brain samples of mice and corresponded to 81% of parent remained by 30min after a tail-vein injection. These results suggest that [(18)F]2 is a promising probe for evaluation of Aß plaques imaging in brain using PET.

A new SIRT1 inhibitor, MHY2245, induces autophagy and inhibits energy metabolism via PKM2/mTOR pathway in human ovarian cancer cells.

Ovarian cancer is a common gynecological cancer that is found worldwide. Class III histone deacetylase (HDAC) inhibitors, a new class of anticancer agents, induce autophagy in various human cancer cells. The aim of the present study was to investigate the antitumor activity of MHY2245, a new synthetic SIRT inhibitor, on human ovarian cancer cells. We found that MHY2245 exhibited potent cytotoxicity to SKOV3 cells in a time- and concentration-dependent manner. The cytotoxicity of MHY2245 (IC50=0.32 µM) was higher than that of doxorubicin (DOX, IC50=1.38µM) against SKOV3 cells. MHY2245 significantly inhibited SIRT1 enzyme activity, reduced the expression of SIRT1, increased cell cycle arrest at G2/M phase, and induced apoptotic cell death in SKOV3 cells via expression of cytochrome c, cleaved-PARP, cleaved caspase-3, and Bax. This might be associated with blocking of the pyruvate kinase M2 (PKM2)/mTOR pathway. MHY2245 also inhibited tumor growth and reduced tumor size when SKOV3 cells were transplanted into nude mice. Our results indicate that MHY2245 exerts antitumor activity against ovarian cancer cells by blocking the PKM2/mTOR pathway. We suggest that MHY2245 is a promising anticancer agent that disrupts ovarian cancer cell metabolism.

A New Histone Deacetylase Inhibitor, MHY4381, Induces Apoptosis via Generation of Reactive Oxygen Species in Human Prostate Cancer Cells.

Histone deacetylase (HDAC) inhibitors represent a novel class of anticancer agents, which can be used to inhibit cell proliferation and induce apoptosis in several types of cancer cells. In this study, we investigated the anticancer activity of MHY4381, a newly synthesized HDAC inhibitor, against human prostate cancer cell lines and compared its efficacy with that of suberoylanilide hydroxamic acid (SAHA), a well-known HDAC inhibitor. We assessed cell viability, apoptosis, cell cycle regulation, and other biological effects in the prostate cancer cells. We also evaluated a possible mechanism of MHY4381 on the apoptotic cell death pathway. The IC50 value of MHY4381 was lower in DU145 cells (IC50=0.31 µM) than in LNCaP (IC50=0.85 µM) and PC-3 cells (IC50=5.23 µM). In addition, the IC50 values of MHY4381 measured in this assay were significantly lower than those of SAHA against prostate cancer cell lines. MHY4381 increased the levels of acetylated histones H3 and H4 and reduced the expression of HDAC proteins in the prostate cancer cell lines. MHY4381 increased G2/M phase arrest in DU145 cells, and G1 arrest in LNCaP cells. It also activated reactive oxygen species (ROS) generation, which induced apoptosis in the DU145 and LNCaP cells by increasing the ratio of Bax/Bcl-2 and releasing cytochrome c into the cytoplasm. Our results indicated that MHY4381 preferentially results in antitumor effects in DU145 and LNCaP cells via mitochondria-mediated apoptosis and ROS-facilitated cell death pathway, and therefore can be used as a promising prostate cancer therapeutic.

Dendropanax morbifera Protects against Renal Fibrosis in Streptozotocin-Induced Diabetic Rats.

The aquatic extract of Dendropanax morbifera (DP) is typically consumed as a beverage in Korea and China and is also used in various traditional medicines. However, the functional role of DP on diabetes-induced renal fibrosis is unclear. Here, the protective effects of DP extract against diabetes-induced renal fibrosis were evaluated. Streptozotocin (STZ, 60 mg/kg) was injected intraperitoneally in rats to induce diabetes. After 5 days, DP extract (25 mg/kg/day) and metformin (50 mg/kg/day) were administered orally to diabetic rats for 28 days. DP administration protected both body and organ weight loss in STZ-treated diabetic rats. Significant improvements in serum blood urea nitrogen (BUN), creatinine, and oxidative stress parameters were observed in diabetic rats by DP administration. DP extract markedly protected diabetic-induced histopathological damages in the kidney and pancreas. A significant reduction was observed in microalbumin, kidney injury molecule-1 (KIM-1), selenium binding protein-1 (SBP1), and pyruvate kinase muscle isozyme M2 (PKM2) levels in the urinary excretion of diabetic rats after the administration of DP extract. The expression of pro-inflammatory cytokines and fibrosis marker levels were significantly reduced in the kidney of diabetic rats. Our results strongly indicate that DP extract exhibits protective activity against diabetes-induced renal fibrosis through ameliorating oxidative stress and inflammation. Therefore, we suggest that DP extract can be used as a preventive agent on the progression of diabetic nephropathy and renal fibrosis.

Protective Effects of Dendropanax morbifera against Cisplatin-Induced Nephrotoxicity without Altering Chemotherapeutic Efficacy.

Use of the chemotherapeutic agent cisplatin (CDDP) in cancer patients is limited by the occurrence of acute kidney injury (AKI); however, no protective therapy is available. We aimed to investigate the renoprotective effects of Dendropanax morbifera water extract (DM) on CDDP-induced AKI. Male Sprague-Dawley rats (six animals/group) received: Vehicle (control); CDDP (6 mg/kg, intraperitoneally (i.p.); DM (25 mg/kg, oral); or DM + CDDP injection. CDDP treatment significantly increased blood urea nitrogen (BUN), serum creatinine (sCr), and pro-inflammatory cytokines (IL-6 and TNF-α), and severely damaged the kidney architecture. Urinary excretion of protein-based AKI biomarkers also increased in the CDDP-treated group. In contrast, DM ameliorated CDDP-induced AKI biomarkers. It markedly protected against CDDP-induced oxidative stress by increasing the activity of endogenous antioxidants and reducing the levels of pro-inflammatory cytokines (IL-6 and TNF-α). The protective effect of DM in the proximal tubules was evident upon histopathological examination. In a tumor xenograft model, administration of DM enhanced the chemotherapeutic activity of CDDP and exhibited renoprotective effects against CDDP-induced nephrotoxicity without altering chemotherapeutic efficacy. Our data demonstrate that DM may be an adjuvant therapy with CDDP in solid tumor patients to preserve renal function.

Plumbagin from a tropical pitcher plant (Nepenthes alata Blanco) induces apoptotic cell death via a p53-dependent pathway in MCF-7 human breast cancer cells.

Plumbagin (5-hydroxy-2-methyl-1,4-naphthaquinone) has displayed antitumor activity in vitro and in animal models; however, the underlying molecular mechanisms have not been fully explored. The aim of this study was to investigate the anticancer effects of plumbagin isolated from Nepenthes alata against MCF-7 breast cancer cells. We examined the cytotoxicity, cell cycle regulation, apoptotic cell death, and generation of intracellular reactive oxygen species (ROS) in MCF-7 cells. Plumbagin exhibited potent cytotoxicity in MCF-7 cells (wild-type p53) compared to that in SK-OV-3 (null-type) human epithelial ovarian cancer cells. Specifically, plumbagin upregulated the expression of p21CIP1/WAF1 in MCF-7 cells, causing cell cycle arrest in the G2/M phase through inhibition of cyclin B1 levels. Plumbagin also significantly increased the ratio of Bax/Bcl-2 and release of cytochrome c, resulting in apoptotic cell death in MCF-7 cells. Furthermore, plumbagin dramatically increased the intracellular ROS level, whereas pretreatment with the ROS scavenger N-acetyl cysteine protected against plumbagin-induced cytotoxicity, suggesting that ROS formation plays a pivotal role in antitumor activity in MCF-7 cells. In mice bearing MCF-7 cell xenografts, plumbagin significantly reduced tumor growth and weight without apparent side effects. We therefore concluded that plumbagin exerts anticancer activity against MCF-7 cells through the generation of intracellular ROS, resulting in the induction of apoptosis via a p53-dependent pathway. This study thus identifies a new anticancer mechanism of plumbagin against p53-dependent breast cancer cells and suggests a novel strategy for overcoming of breast cancer therapy.

Aging-related Repositioned Drugs, Donepezil and Sildenafil Citrate, Increase Apoptosis of Anti-mitotic Drug-resistant KBV20C Cells Through Different Molecular Mechanisms.

BACKGROUND/AIM: The study focused on identifying the mechanisms or drugs that could sensitize P-glycoprotein (P-gp)-overexpressing resistant KBV20C cancer cells to halaven (HAL) or vincristine (VIC) treatment. MATERIALS AND METHODS: Based on the relatively low dose or IC50 values for sensitizing anti-mitotic drug-resistant KBV20C cells, the aging-related drugs donepezil (DON) and sildenafil citrate (SID) were selected. Fluorescence-activated cell sorting (FACS), western blotting, and annexin V analyses were performed to investigate the mechanism of action of DON and SID in HAL-treated KBV20C cells. RESULTS: DON or SID reduced cell viability, increased G2 arrest, and up-regulated the expression of the DNA damaging protein pH2AX when used as co-treatment with HAL. DON and SID induced both early and late apoptosis in KBV20C cells in response to HAL treatment, without increasing autophagy. VIC-DON and VIC-SID co-treatments increased sensitization of KBV20C cells, suggesting that DON and SID can be combined with other anti-mitotic drugs for sensitizing resistant cancer cells. When the sensitization efficacies of DON and SID were compared to that of the anti-psychotic repositioned drug fluphenazine (FLU), HAL-SID or HAL-FLU co-treatments were found to have better sensitization effects than HAL-DON suggesting that HAL-SID sensitization mechanism is different from that of HAL-DON. In addition, DON was found to have higher P-gp inhibitory activity than FLU or SID. CONCLUSION: These results suggest that HAL-FLU or HAL-SID sensitization in KBV20C cells involves both cytotoxic and P-gp inhibitory effects, whereas HAL-DON sensitization may involve only P-gp inhibitory activity of DON.