Auriculasin enhances ROS generation to regulate colorectal cancer cell apoptosis, ferroptosis, oxeiptosis, invasion and colony formation.

Colorectal cancer (CRC) is one of the most common malignant tumors in the digestive system, and Chinese herbal medicine plays an important role in tumor treatment. The in-depth study of auriculasin isolated from Flemingia philippinensis showed that auriculasin promoted reactive oxygen species (ROS) generation in a concentration-dependent manner; when ROS scavenger NAC was added, the effects of auriculasin in promoting ROS generation and inhibiting cell viability were blocked. Auriculasin induced CRC cell apoptosis, led to mitochondrial shrinkage, and increased the intracellular accumulation of Fe2+ and MDA. When auriculasin and NAC were added simultaneously, the levels of apoptosis, Fe2+ and MDA returned to the control group levels, indicating that auriculasin activated apoptosis and ferroptosis by inducing ROS generation. In addition, auriculasin promoted the expression of Keap1 and AIFM1, but significantly reduced the phosphorylation level of AIFM1, while NAC significantly blocked the regulation of Keap1 and AIFM1 by auriculasin, which indicates that auriculasin can also induce oxeiptosis through ROS. When Z-VAD-FMK, Ferrostatin-1, Keap1 siRNA, PGAM5 siRNA and AIFM1 siRNA were added respectively, the inhibitory effect of auriculasin on cell viability was significantly weakened, indicating that auriculasin inhibits cell viability by inducing apoptosis, ferroptosis and oxeiptosis. Auriculasin also inhibited the invasion and clone forming ability of CRC cells, while NAC blocked the above effects of auriculasin. Therefore, auriculasin can promote CRC cell apoptosis, ferroptosis and oxeiptosis by inducing ROS generation, thereby inhibiting cell viability, invasion and clone formation, indicating that auriculasin has a significant antitumor effect.

Structural properties and in vitro and in vivo immunomodulatory activity of an arabinofuranan from the fruits of Akebia quinata.

In our continuous searching for natural active polysaccharides with immunomodulatory activity, an arabinofuranan (AQP70-3) was isolated and purified from the fruits of Akebia quinata (Houtt.) Decne. by using ion-exchange chromatography and gel permeation chromatography for the first time. AQP70-3 contained both α-l-Araf and ß-l-Araf, and the absolute molecular weight was 1.06 × 104 g/mol. The backbone of AQP70-3 comprised →5)-α-l-Araf-(1→, →3,5)-α-l-Araf-(1→, and →2,5)-α-l-Araf-(1→, with branches of →1)-ß-l-Arafand →3)-α-l-Araf-(1→ residues. Biological assay suggested that AQP70-3 can stimulate phagocytic activity and promote the levels of nitric oxide (NO), interleukin (IL)-6, IL-1ß, and tumor necrosis factor-α (TNF-α) of RAW264.7 cells. Furthermore, AQP70-3 was found to increase the production of reactive oxygen species (ROS) and NO in zebrafish embryo model.

Sodium Valproate, a Histone Deacetylase Inhibitor, Provokes Reactive Oxygen Species-Mediated Cytotoxicity in Human Hepatocellular Carcinoma Cells.

BACKGROUND AND AIM: Sodium valproate (SV), a novel class of histone deacetylases (HDACs) inhibitors commonly used as an antiepileptic drug. HDAC inhibitors are known to possess anticancer potentials. In this study, we investigated the cytotoxic potential of SV in human hepatocellular carcinoma (HepG2 cells) cell line. METHODS: MTT assay was used to analyze cytotoxicity. Intracellular ROS and cytochrome c expression were analyzed by fluorescence microscopy. Morphology-related apoptosis was analyzed by dual staining with acridine orange/ethidium bromide. Caspase 3 protein expression was investigated by Western blotting analysis. RESULTS: Sodium valproate treatments in HepG2 cells caused significant and dose-dependent cytotoxicity. Intracellular ROS was remarkably increased in the cells which are treated with SV and caused early and late apoptosis as evidenced by dual staining. SV-treated cells expressed cytochrome c and caspase 3 protein expression. CONCLUSION: These results suggest the cytotoxic potentials of SV in HepG2 cells. This study may give an important clue for the inclusion of SV as an adjuvant along with standard anticancer agents after necessary in vivo and clinical studies.

Knockdown of dual oxidase 1 suppresses activin A-induced fibrosis in cardiomyocytes via the reactive oxygen species-dependent pyroptotic pathway.

Fibrotic diseases account for more than 8 million deaths worldwide annually. Reactive oxygen species (ROS) has been shown to activate pyroptosis and promote the production of interleukin (IL)-1ß and IL-18, leading to fibrosis development. However, the role of dual oxidase 1 (DUOX1)-induced ROS production and pyroptosis in cardiac fibrosis remains largely unknown. Activin A was used to induce ROS and pyroptosis in cardiomyocytes. ROS level, pyroptosis, and cytokine production were detected using Active Oxygen Detection Kit, flow cytometry, and enzyme-linked immunosorbent assay, respectively. Western blotting analysis was used to measure expression changes of proteins. DUOX1 was silenced or overexpressed to investigate its role in fibrosis. We found that activin A induced ROS production and pyroptosis in cardiomyocytes, which was blocked by the ROS scavenger, N-acetyl-L-cysteine (NAC). Knockdown of DUOX1 reversed activin A-induced ROS production, pyroptosis, cytokine release, and the upregulation of proinflammatory proteins. Overexpression of DUOX1 resulted in opposite effects of knockdown DUOX1. Administration of an ROS scavenger blocked the effect of DUOX1 overexpression. Supplementation of IL-1ß and IL-18 caused significant fibrosis in human cardiac fibroblasts (hCFs). The knockdown of DUOX1 protected cardiomyocytes against activin A-induced fibrosis via the inhibition of ROS, cytokine release, and pyroptosis.

Senna plant generates reactive oxygen species (ROS) and induces apoptosis in Hymenolepis diminuta.

Like mammalian cells, helminth parasites are equipped with an array of enzymatic anti-oxidant system which has an adaptive strategy to cope up with several conditions of stress that arise from host immune response or drug treatment. Earlier, we had reported that three species of Senna, viz. S. alata, S. alexandrina and S. occidentalis leaf extracts caused severe morphological and biochemical alterations in the zoonotic parasite Hymenolepis diminuta. To understand whether the leaf extracts of the three species of Senna have any effect on the enzymatic anti-oxidant system in H.diminuta or not, the present study was investigated on the mechanism of action of these leaf extracts on the anti-oxidant system of the parasite. The viability of the parasite was assessed by MTT reduction assay, chromatin condensation through Hoechst staining of tissue and DNA fragmentation assay, and the oxidative enzymes of the parasite were estimated biochemically. Activity of superoxide dismutase, catalase, glutathione S- transferase and glutathione peroxidase were found to be increased in all the treated parasites from that of the control, with S. alata showed the highest increased amongst the three plant species in all the enzymes, at 331.0 %, 215.4 %, 85.4 % and 65.5 % respectively. Upliftment of apoptotic protein CED-3, CED-4 and EGL-1 and down regulation of anti-apototic protein CED-9 was visualised in all treated paraites. The redox imbalance triggered by these leaf extracts resulted in the activation of apoptotic pathway that led to death of the parasite. Our results demonstrated that the leaf extracts of the three Senna plant species could open new insight for an affordable natural anthelmintic with high efficacy and less toxicity.

Gedunin isolated from the mangrove plant Xylocarpus granatum exerts its anti-proliferative activity in ovarian cancer cells through G2/M-phase arrest and oxidative stress-mediated intrinsic apoptosis.

Gedunin is a natural tetranorterpenoid secondary metabolite found in plants of the Meliaceae family, which has been reported for its antiparasitic, antifungal and anticancer activities. Here, we describe the molecular mechanisms underlying the in vitro anti proliferative activity of gedunin (isolated from the mangrove plant Xylocarpus granatum) in human ovarian cancer cells. We observed that gedunin triggered severe ROS generation leading to DNA damage and cell cycle arrest in G2/M phase thus inhibiting cell proliferation. ROS upregulation also led to mitochondrial stress and membrane depolarization, which eventually resulted in mitochondria-mediated apoptosis following cytochrome C release, caspase 9, 3 activation, and PARP cleavage. Transmission electron microscopy of gedunin treated cells revealed sub-cellular features typical of apoptosis. Moreover, an upregulation in stress kinases like phospho-ERK 1/2, phospho-p38 and phospho-JNK was also observed in gedunin treated cells. Free radical scavenger N-Acetyl-L-Cysteine (NAC) reversed all these effects resulting in increased cell survival, abrogation of cell cycle arrest, rescue of mitochondrial membrane potential and suppression of apoptotic markers. Interestingly, gedunin is also an inhibitor of the evolutionarily conserved molecular chaperone Heat Shock Protein 90 (hsp90) responsible for maintaining cellular homeostasis. Targeting this chaperone could be an attractive strategy for developing cancer therapeutics since many oncogenic proteins are also client proteins of hsp90. Collectively, our findings provide insights into the molecular mechanism of action of gedunin, which may aid drug development efforts against ovarian cancer.

VEGF and bFGF induction by nitric oxide is associated with hyperbaric oxygen-induced angiogenesis and muscle regeneration.

Hyperbaric oxygen (HBO) treatment promotes early recovery from muscle injury. Reactive oxygen species (ROS) upregulation is a key mechanism of HBO, which produces high O2 content in tissues through increased dissolution of oxygen at high pressure. Nitric oxide (NO), a type of ROS, generally stabilizes hypoxia-inducible factor (HIF) 1α and stimulates secretion of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) from endothelial cells and macrophages, which then induces angiogenesis. The purpose of the present study was to investigate whether HBO could promote angiogenesis via induction of NO and induce muscle regeneration in contused rat skeletal muscles. The HBO protocol consisted of 2.5 atmospheres absolute (ATA) 100% oxygen for 120 minutes, once a day for 5 consecutive days. We also evaluated the effects of a ROS inhibitor (NAC) or NOS-specific inhibitor (L-NAME) on HBO. HBO significantly increased NO3-, VEGF, and bFGF levels and stabilized HIF1α within 1 day. HBO promoted blood vessel formation at 3-7 days and muscle healing at 5-7 days after contusion. Administration of both NAC and L-NAME before HBO suppressed angiogenesis and muscle regeneration even after HBO. HBO thus promoted angiogenesis and muscle regeneration mainly through generation of NO in the early phase after muscle contusion injury.

Organic small molecular nanoparticles based on self-assembly of amphiphilic fluoroporphyrins for photodynamic and photothermal synergistic cancer therapy.

Two new porphyrin-based organic compounds (Por and ZnPor) were synthesized by introducing hydrophilic polyethylene glycol chains and pentafluorobenzene moieties onto the parent porphyrin structure. After self-assembling into nanoparticles, the absorption spectrum of (Zn)Por NPs broadened and red-shifted to some extent, relative to that of organic molecules. Meanwhile, the fluorescence of organic molecule nanoparticles was quenched significantly, which facilitated the nonradiative thermal generation for potential applications in photothermal cancer therapy. Por NPs and ZnPor NPs presented spherical structure with average diameter about 100 nm, endowing them with tumor targeting properties based on the enhanced permeability and retention (EPR) effect. Due to the heavy atom effect, ZnPor NPs presented the higher efficiency of ROS generation than that of Por NPs. In contrast, Por NPs exhibited the better photothermal effect relative to that of ZnPor NPs under irradiation of a 635-nm laser. The photothermal conversion efficiency of Por NPs was calculated to be 16.34%. The in vitro experiments suggested that Por NPs and ZnPor NPs could enter tumor cells efficiently with good biocompatibility and exhibited high photocytotoxicity with IC50 of 7.3 µg/mL and 3.0 µg/mL, respectively. Thus, the as-prepared porphyrin nanomaterials can be used as potential photosensitizers for cancer photodynamic/photothermal synergistic therapy in vivo, benefiting from their good biocompatibility, strong near-infrared absorption, and high photodynamic and photothermal effects.

Neuroprotective Effects of Taraxacum officinale Wigg. Extract on Glutamate-Induced Oxidative Stress in HT22 Cells via HO-1/Nrf2 Pathways.

Oxidative stress-mediated neuron damage is considered an important contributor to the pathogenesis and development of neurodegenerative diseases. Taraxacum officinale has been reported to possess antioxidant activities. However, whether it can protect neurons against oxidative damage and the underlying molecular mechanisms have not been fully determined. In the present study, we examined the neuroprotective effects of ethanol extracts of this plant (ETOW) on glutamate-induced oxidative stress in HT22 cells. Both cell viability and reactive oxygen species (ROS) assays showed that ETOW effectively attenuated glutamate-induced cytotoxicity and ROS generation. Furthermore, our results revealed that ETOW increased the expression of heme oxygenase-1 (HO-1) and promoted the nuclear translocation of nuclear factor erythroid 2-related factor-2 (Nrf2). The inhibitory effects of ETOW on glutamate-stimulated cell toxicity and ROS production were partially reversed by tin protoporphyrin (SnPP), an HO activity inhibitor. Taken together, these results demonstrate that ETOW can protect HT22 cells against glutamate-induced oxidative damage by inducing the Nrf2/HO-1 pathways. Our study supports the idea that Taraxacum officinale Wigg. is a promising agent for preventing neurodegenerative diseases.

Low-dose dexamethasone affects osteoblast viability by inducing autophagy via intracellular ROS.

Glucocorticoids (GCs) are closely associated with the progression of GC­induced osteoporosis (GIOP) by inhibiting osteoblast viability. However, endogenous GCs are important for bone development. In addition, previous studies have demonstrated that GCs could induce autophagy, a cytoprotective process that is protective against various stressors. In the present study, the aim is to explore whether osteoblasts exhibited dose­dependent viability in the presence of GCs due to autophagy. hFOB 1.19 osteoblasts were treated with various doses of dexamethasone (DEX; 10­8­10­4 M) for 0, 24, 48 and 72 h. The results revealed a biphasic effect of DEX on the viability of hFOB 1.19 cells; a high dose of DEX (≥10­6 M) accelerated cell apoptosis, while a low dose of DEX (10­8 M) increased cell viability. Furthermore, significantly increased autophagy was observed in the low dose DEX treatment group, as indicated by the expression of the autophagy­associated proteins beclin 1 and microtubule­associated protein light chain 3, and the detection of autophagosomes. Another finding was that DEX upregulated intracellular reactive oxygen species (ROS), which was decreased by the autophagy agonist rapamycin. The increase in autophagy and cell viability associated with low­dose DEX (10­8 M) was suppressed by the ROS scavenger catalase and the autophagy inhibitor 3­methyladenine. In conclusion, the results revealed that GCs affected osteoblast viability in a dose­dependent manner. A low dose of GCs increased osteoblast viability by inducing autophagy via intracellular ROS. The results indicate that autophagy may be a novel mechanism by which osteoblasts survive GC exposure and provide a potential therapeutic target for treating GIOP.

The Static Magnetic Field Remotely Boosts the Efficiency of Doxorubicin through Modulating ROS Behaviors.

Exposure to magnetic field (MF) can affect cellular metabolism remotely. Cardio-toxic effects of Doxorubicin (DOXO) have limited clinical uses at high dose. MF due to its effect on reactive oxygen species (ROS) lifetime, may provide a suitable choice to boost the efficacy of this drug at low dose. Here, we investigated the potential effects of homogenous static magnetic field (SMF) on DOXO-induced toxicity and proliferation rate of cancer cells. The results indicated that SMF similar to DOXO decreased the cell viability as well as the proliferation rate of MCF-7 and HFF cells. Moreover, combination of 10 mT SMF and 0.1 µM DOXO decreased the viability and proliferation rate of cancer and normal cells in a synergetic manner. In spite of high a GSH level in cancer cell, SMF boosts the generation and lifetime of ROS at low dose of DOXO, and overcame to GSH mediated drug resistance. The results also confirmed that SMF exposure decreased 50% iron content of cells, which is attributed to iron homeostasis. In conclusion, these findings suggest that SMF can decrease required dose of chemotherapy drugs such as DOXO and thereby decrease their side effect.

Frugal Biotech Applications of Low-Temperature Plasma.

Gas discharge low-temperature air plasma can be utilized for a variety of applications, including biomedical, at low cost. We term these applications 'frugal plasma' - an example of frugal innovation. We demonstrate how simple, robust, low-cost frugal plasma devices can be used to safely disinfect instruments, surfaces, and water.

Bavachin Induces Apoptosis through Mitochondrial Regulated ER Stress Pathway in HepG2 Cells.

As a traditional herbal medicine, the fruits of Psoralea corylifolia L. (Fructus Psoraleae (FP)) have been widely used for the treatment of various skin diseases for hundred years. Recently, the emerging FP-induced toxic effects, especially hepatotoxicity, in clinic are getting the public's attention. However, its exact toxic components and mechanisms underlying remain unclear. Bavachin, one of flavonoids in FP, has been documented as a hepatotoxic substance, and the present study aimed to determine the toxicity caused by bavachin and the possible toxic mechanisms involved using human hepatocellular carcinoma (HepG2) cells. Our results showed that bavachin could significantly inhibited cell proliferation and trigger the endoplasmic reticulum (ER) stress in a dose dependent manner. Downregulating ER stress using tauroursodeoxycholic acid (TUDCA) obvious attenuated bavachin-triggerd cell apoptosis. Then, small interfering RNA (siRNA) knock-down of Mitofusion2 (Mfn2) resulted in a remarkable aggravation of ER stress through the inhibition of the phosphorylation of protein kinase B (Akt). Additionally, suppression of reactive oxygen species (ROS) by ROS Scavenger (N-acetyl-l-cystein (NAC)) also reduced bavachin-induced ER stress. Taken together, our study demonstrated that bavachin-induced ER stress caused cell apoptosis by Mfn2-Akt pathway, and that ROS may participate upstream in this mechanism. Here, we not only provide a new understanding of ROS/Mfn2/Akt pathway in bavachin-induced cytotoxicity via the ER stress, but also identify a new specific intervention to prevent FP-induced hepatotoxicity in the future.

Coumestrol induces mitochondrial dysfunction by stimulating ROS production and calcium ion influx into mitochondria in human placental choriocarcinoma cells.

STUDY QUESTION: Does coumestrol inhibit proliferation of human placental choriocarcinoma cells? SUMMARY ANSWER: Coumestrol promotes cell death in the choriocarcinoma cells by regulating ERK1/2 MAPK and JNK MAPK signaling pathways and through disruption of Ca2+ and ROS homeostasis. WHAT IS KNOWN ALREADY: A number of patients who suffer from choriocarcinomas fail to survive due to delayed diagnosis or a recurrent tumor and resistance to traditional chemotherapy using platinum-based agents and methotrexate. To overcome these limitations, it is important to discover novel compounds which have no adverse effects yet can inhibit the expression of a target molecule to develop, as a novel therapeutic for prevention and/or treatment of choriocarcinomas. STUDY DESIGN, SIZE, DURATION: Effects of coumestrol on human placental choriocarcinoma cell lines, JAR and JEG3, were assessed in diverse assays in a dose- and time-dependent manner. PARTICIPCANTS/MATERIALS, SETTING, METHODS: Effects of coumestrol on cell proliferation, apoptosis (annexin V expression, propidium iodide staining, TUNEL and invasion assays), mitochondria-mediated apoptosis, production of reactive oxygen species (ROS), lipid peroxidation, glutathione levels and endoplasmic reticulum (ER) stress proteins in JAR and JEG3 cells were determined. Signal transduction pathways in JAR and JEG3 cells in response to coumestrol were determined by western blot analyses. MAIN RESULTS AND THE ROLE OF CHANCE: Results of the present study indicated that coumestrol suppressed proliferation and increased apoptosis in JAR and JEG3 cells by inducing pro-apoptotic proteins, Bax and Bak. In addition, coumestrol increased ROS production, as well as lipid peroxidation and glutathione levels in JAR and JEG3 cells. Moreover, coumestrol-induced depolarization of mitochondrial membrane potential (MMP) and increased cytosolic and mitochondrial Ca2+ levels in JAR and JEG3 cells. Consistent with those results, treatment of JAR and JEG3 cells with a Ca2+ chelator and an inhibitor of IP3 receptor decreased coumestrol-induced depolarization of MMP and increased proliferation in JAR and JEG3 cells. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: A lack of in vivo animal studies is a major limitation of this research. The effectiveness of coumestrol to induce apoptosis of human placental choriocarcinoma cells requires further investigation. WIDER IMPLICATIONS OF THE FINDINGS: Our results indicate that coumestrol induces apoptotic effects on placental choriocarcinoma cells by regulating cell signaling and mitochondrial-mediated functions, with a potential to impair progression of the cancer. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by grants from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (No. HI15C0810 awarded to G.S. and HI17C0929 awarded to W.L.).

Dietary resveratrol confers apoptotic resistance to oxidative stress in myoblasts.

High levels of reactive oxygen species (ROS) contribute to muscle cell death in aging and disuse. We have previously found that resveratrol can reduce oxidative stress in response to aging and hindlimb unloading in rodents in vivo, but it was not known if resveratrol would protect muscle stem cells during repair or regeneration when oxidative stress is high. To test the protective role of resveratrol on muscle stem cells directly, we treated the C2C12 mouse myoblast cell line with moderate (100 µM) or very high (1 mM) levels of H2O2 in the presence or absence of resveratrol. The p21 promoter activity declined in myoblasts in response to high ROS, and this was accompanied a greater nuclear to cytoplasmic translocation of p21 in a dose-dependent matter in myoblasts as compared to myotubes. Apoptosis, as indicated by TdT-mediated dUTP nick-end labeling, was greater in C2C12 myoblasts as compared to myotubes (P<.05) after treatment with H2O2. Caspase-9, -8 and -3 activities were elevated significantly (P<.05) in myoblasts treated with H2O2. Myoblasts were more susceptible to ROS-induced oxidative stress than myotubes. We treated C2C12 myoblasts with 50 µM of resveratrol for periods up to 48 h to determine if myoblasts could be rescued from high-ROS-induced apoptosis by resveratrol. Resveratrol reduced the apoptotic index and significantly reduced the ROS-induced caspase-9, -8 and -3 activity in myoblasts. Furthermore, Bcl-2 and the Bax/Bcl-2 ratio were partially rescued in myoblasts by resveratrol treatment. Similarly, muscle stem cells isolated from mouse skeletal muscles showed reduced Sirt1 protein abundance with H2O2 treatment, but this could be reversed by resveratrol. Reduced apoptotic susceptibility in myoblasts as compared to myotubes to ROS is regulated, at least in part, by enhanced p21 promoter activity and nuclear p21 location in myotubes. Resveratrol confers further protection against ROS by improving Sirt1 levels and increasing antioxidant production, which reduces mitochondrial associated apoptotic signaling, and cell death in myoblasts.

Monitoring ZEO apoptotic potential in 2D and 3D cell cultures and associated spectroscopic evidence on mode of interaction with DNA.

Recognizing new anticancer compounds to improve Breast cancer treatment seems crucial. Essential oil of Zataria Multiflora (ZEO) is a secondary metabolite with some biological properties, yet underlying cellular and molecular anticancer properties of ZEO is unclear. GC/MS analysis revealed that carvacrol is the major ingredient of the essential oil. ZEO increasingly suppressed viability in MDA-MB-231, MCF-7 and T47D Breast cancer cells while nontoxic to L929 normal cells in monolayer cell cultures (2D), whereas MDA-MB-231 multicellular spheroids (3D) were more resistant to inhibition. ZEO significantly induced cell apoptosis confirmed by fluorescent staining, flow cytometry analysis and DNA fragmentation in MDA-MB-231 2D and 3D cell cultures. ZEO increased ROS generation and subsequent loss of ΔΨm, caspase 3 activation and DNA damage which consequently caused G1 and G2/M cell cycle arrest in a dose- and time-dependent manner in 2D. S phase arrest occurred in cell spheroids therefore ZEO possible DNA interaction with gDNA was investigated and revealed ZEO binds DNA via intercalation. Altogether, these data corroborate anticancer properties of ZEO and suggest that cell culture format (2D monolayer vs. 3D spheroid) plays a critical role in drug response and provides new insights into the mechanisms underlying ZEO cytotoxicity effect on Breast cancer cells.

Ruthenium complex exerts antineoplastic effects that are mediated by oxidative stress without inducing toxicity in Walker-256 tumor-bearing rats.

The present study evaluated the in vivo antitumor effects and toxicity of a new Ru(II) compound, cis-(Ru[phen]2[ImH]2)2+ (also called RuphenImH [RuC]), against Walker-256 carcinosarcoma in rats. After subcutaneous inoculation of Walker-256 cells in the right pelvic limb, male Wistar rats received 5 or 10mgkg-1 RuC orally or intraperitoneally (i.p.) every 3 days for 13 days. A positive control group (2mgkg-1 cisplatin) and negative control group (vehicle) were also used. Tumor progression was checked daily. After treatment, tumor weight, plasma biochemistry, hematology, oxidative stress, histology, and tumor cell respiration were evaluated. RuC was effective against tumors when administered i.p. but not orally. The highest i.p. dose of RuC (10mgkg-1) significantly reduced tumor volume and weight, induced oxidative stress in tumor tissue, reduced the respiration of tumor cells, and induced necrosis but did not induce apoptosis in the tumor. No clinical signs of toxicity or death were observed in tumor-bearing or healthy rats that were treated with RuC. These results suggest that RuC has antitumor activity through the modulation of oxidative stress and impairment of oxidative phosphorylation, thus promoting Walker-256 cell death without causing systemic toxicity. These effects make RuC a promising anticancer drug for clinical evaluation.

A novel ECG analog 4-(S)-(2,4,6-trimethylthiobenzyl)-epigallocatechin gallate selectively induces apoptosis of B16-F10 melanoma via activation of autophagy and ROS.

Autophagy-induced cancer cell death has become a novel strategy for the development of cancer therapeutic drugs. Numerous studies have indicated that green tea polyphenols induce both autophagy and apoptosis in a variety of cancer cells. Here, we synthesized a series of green tea polyphenol analogues, among which JP8 was shown to potently activate autophagy. JP8 treatment had a stronger effect on apoptosis in B16-F10 melanoma cells than that in normal AML-12 hepatocytes. JP8 selectively resulted in reactive oxygen species (ROS) accumulation in B16-F10 cells, and this effect was associated with corresponding increases in key components of the ER stress-mediated apoptosis pathway. Pharmacological inhibition of ROS by N-acetyl-L-cysteine (NAC) attenuated JP8-induced autophagy and apoptosis, indicating an upstream role of ROS in JP8-induced autophagy. An in vivo study showed that JP8 had significant antitumor effects in a B16-F10 xenograft mouse model. Our results indicate that JP8 is a novel anticancer candidate with both autophagy and ROS induction activities.

Polyphenolics from mango (Mangifera indica L.) suppress breast cancer ductal carcinoma in situ proliferation through activation of AMPK pathway and suppression of mTOR in athymic nude mice.

The objective of this study was to assess the underlying mechanisms of mango polyphenol decreased cell proliferation and tumor volume in ductal carcinoma in situ breast cancer. We hypothesized that mango polyphenols suppress signaling along the AKT/mTOR axis while up-regulating AMPK. To test this hypothesis, mango polyphenols (0.8 mg gallic acid equivalents per day) and pyrogallol (0.2 mg/day) were administered for 4 weeks to mice xenografted with MCF10DCIS.com cells subcutaneously (n=10 per group). Tumor volumes were significantly decreased, both mango and pyrogallol groups displayed greater than 50% decreased volume compared to control. There was a significant reduction of phosphorylated protein levels of IR, IRS1, IGF-1R, and mTOR by mango; while pyrogallol significantly reduced the phosphorylation levels of IR, IRS1, IGF-1R, p70S6K, and ERK. The protein levels of Sestrin2, which is involved in AMPK-signaling, were significantly elevated in both groups. Also, mango significantly elevated AMPK phosphorylation and pyrogallol significantly elevated LKB1 protein levels. In an in vitro model, mango and pyrogallol increased reactive oxygen species (ROS) generation and arrested cells in S phase. In silico modeling indicates that pyrogallol has the potential to bind directly to the allosteric binding site of AMPK, inducing activation. When AMPK expression was down-regulated using siRNA in vitro, pyrogallol reversed the reduced expression of AMPK. This indicates that pyrogallol not only activates AMPK, but also increases constitutive protein expression. These results suggest that mango polyphenols and their major microbial metabolite, pyrogallol, inhibit proliferation of breast cancer cells through ROS-dependent up-regulation of AMPK and down-regulation of the AKT/mTOR pathway.

Nanotized Curcumin and Miltefosine, a Potential Combination for Treatment of Experimental Visceral Leishmaniasis.

Leishmaniasis chemotherapy remains very challenging due to high cost of the drug and its associated toxicity and drug resistance, which develops over a period of time. Combination therapies (CT) are now in use to treat many diseases, such as cancer and malaria, since it is more effective and affordable than monotherapy. CT are believed to represent a new explorable strategy for leishmaniasis, a neglected tropical disease caused by the obligate intracellular parasite Leishmania In the present study, we investigated the effect of a combination of a traditional Indian medicine (ayurveda), a natural product curcumin and miltefosine, the only oral drug for visceral leishmaniasis (VL) using a Leishmania donovani-hamster model. We developed an oral nanoparticle-based formulation of curcumin. Nanoformulation of curcumin alone exhibited significant leishmanicidal activity both in vitro and in vivo In combination with miltefosine, it exhibited a synergistic effect on both promastigotes and amastigotes under in vitro conditions. The combination of these two agents also demonstrated increased in vivo leishmanicidal activity accompanied by increased production of toxic reactive oxygen/nitrogen metabolites and enhanced phagocytic activity. The combination also exhibited increased lymphocyte proliferation. The present study thus establishes the possible use of nanocurcumin as an adjunct to antileishmanial chemotherapy.