Enhanced anti-tumor activity of transferrin/folate dual-targeting magnetic nanoparticles using chemo-thermo therapy on retinoblastoma cancer cells Y79.

Malignant neoplasms are one of the main causes of death, especially in children, on a global scale, despite strenuous efforts made at advancing both diagnostic and therapeutic modalities. In this regard, a new nanocarrier Vincristine (VCR)-loaded Pluronic f127 polymer-coated magnetic nanoparticles conjugated with folic acid and transferrin (PMNP-VCR-FA-TF) were synthesized and characterized by various methods. The cytotoxicity of these nanoparticles was evaluated in vitro and ex vivo conditions. The in vitro anti-tumor effect of the nanoparticles was evaluated by colony formation assay (CFA) and reactive oxygen species (ROS) in Y79 cell line. The results showed that nanoparticles with two ligands conferred greater toxicity toward Y79 cancer cells than ARPE19 normal cells. Under an alternating magnetic field (AMF), these nanoparticles demonstrated a high specific absorption rate. The CFA and ROS results indicated that the AMF in combination with PMNP-VCR-FA-TF conferred the highest cytotoxicity toward Y79 cells compared with other groups (P < 0.05). PMNP-VCR-FA-TF could play an important role in converting externally applied radiofrequency energy into heat in cancer cells. The present study confirmed that dual targeting chemo-hyperthermia using PMNP-VCR-FA-TF was significantly more effective than hyperthermia or chemotherapy alone, providing a promising platform for precision drug delivery as an essential component in the chemotherapy of retinoblastoma.

Potentiating Biosynthesis of Alkaloids and Polyphenolic Substances in Catharanthus roseus Plant Using ĸ-Carrageenan.

Catharanthus roseus is a medicinal plant that produces indole alkaloids, which are utilized in anticancer therapy. Vinblastine and vincristine, two commercially important antineoplastic alkaloids, are mostly found in the leaves of Catharanthus roseus. ĸ-carrageenan has been proven as plant growth promoting substance for a number of medicinal and agricultural plants. Considering the importance of ĸ-carrageenan as a promoter of plant growth and phytochemical constituents, especially alkaloids production in Catharanthus roseus, an experiment was carried out to explore the effect of ĸ-carrageenan on the plant growth, phytochemicals content, pigments content, and production of antitumor alkaloids in Catharanthus roseus after planting. Foliar application of ĸ-carrageenan (at 0, 400, 600 and 800 ppm) significantly improved the performance of Catharanthus roseus. Phytochemical analysis involved determining the amount of total phenolics (TP), flavonoids (F), free amino acids (FAA), alkaloids (TAC) and pigments contents by spectrophotometer, minerals by ICP, amino acids, phenolic compounds and alkaloids (Vincamine, Catharanthine, Vincracine (Vincristine), and vinblastine) analysis uses HPLC. The results indicated that all examined ĸ-carrageenan treatments led to a significant (p ≤ 0.05) increase in growth parameters compared to the untreated plants. Phytochemical examination indicates that the spray of ĸ-carrageenan at 800 mg L-1 increased the yield of alkaloids (Vincamine, Catharanthine and Vincracine (Vincristine)) by 41.85 µg/g DW, total phenolic compounds by 3948.6 µg gallic/g FW, the content of flavonoids 951.3 µg quercetin /g FW and carotenoids content 32.97 mg/g FW as compared to the control. An amount of 400 ppm ĸ-carrageenan treatment gave the best contents of FAA, Chl a, Chl b and anthocyanin. The element content of K, Ca, Cu, Zn and Se increased by treatments. Amino acids constituents and phenolics compounds contents were altered by ĸ-carrageenan.

Ginger Constituent 6-Shogaol Attenuates Vincristine-Induced Activation of Mouse Gastroesophageal Vagal Afferent C-Fibers.

Chemotherapeutic agent-induced nausea and vomiting are the severe adverse effects that are induced by their stimulations on the peripheral and/or central emetic nerve pathways. Even though ginger has been widely used as an herbal medicine to treat emesis, mechanisms underlying its neuronal actions are still less clear. The present study aimed to determine the chemotherapeutic agent vincristine-induced effect on gastroesophageal vagal afferent nerve endings and the potential inhibitory role of ginger constituent 6-shogaol on such response. Two-photon neuron imaging studies were performed in ex vivo gastroesophageal-vagal preparations from Pirt-GCaMP6 transgenic mice. Vincristine was applied to the gastroesophageal vagal afferent nerve endings, and the evoked calcium influxes in their intact nodose ganglion neuron somas were recorded. The responsive nodose neuron population was first characterized, and the inhibitory effects of 5-HT3 antagonist palonosetron, TRPA1 antagonist HC-030031, and ginger constituent 6-shogaol were then determined. Vincristine application at gastroesophageal vagal afferent nerve endings elicited intensive calcium influxes in a sub-population of vagal ganglion neurons. These neurons were characterized by their positive responses to P2X2/3 receptor agonist α,ß-methylene ATP and TRPA1 agonist cinnamaldehyde, suggesting their nociceptive placodal nodose C-fiber neuron lineages. Pretreatment with TRPA1 selective blocker HC-030031 inhibited vincristine-induced calcium influxes in gastroesophageal nodose C-fiber neurons, indicating that TRPA1 played a functional role in mediating vincristine-induced activation response. Such inhibitory effect was comparable to that from 5-HT3 receptor antagonist palonosetron. Alternatively, pretreatment with ginger constituent 6-shogaol significantly attenuated vincristine-induced activation response. The present study provides new evidence that chemotherapeutic agent vincristine directly activates vagal nodose nociceptive C-fiber neurons at their peripheral nerve endings in the upper gastrointestinal tract. This activation response requires both TRPA1 and 5-HT3 receptors and can be attenuated by ginger constituent 6-shogaol.

Bioactivity inspired C19-diterpenoid alkaloids for overcoming multidrug-resistant cancer.

The pharmacological activities of C19-diterpenoid alkaloids are related to their basic skeletons (e.g., aconitine-type or lycoctonine-type). Also, few studies have been reported on the chemosensitizing effects of diterpenoid alkaloids. Consequently, this study was aimed at determining the chemosensitizing effects of synthetic derivatives of lycoctonine-type C19-diterpenoid alkaloids on a P-glycoprotein (P-gp)-overexpressing multidrug-resistant (MDR) cancer cell line KB-VIN. The acyl-derivatives of delpheline and delcosine showed moderate cytotoxicity against chemosensitive cancer cell lines. Among non-cytotoxic synthetic analogs (1-14), several derivatives effectively and significantly sensitized MDR cells by interfering with the drug transport function of P-gp to three anticancer drugs, vincristine, paclitaxel, and doxorubicin. The chemosensitizing effect of derivatives 2, 4, and 6 on KB-VIN cells against vincristine were more potent than 5 µM verapamil, and derivatives 4 and 13 were more effective than 5 µM verapamil for paclitaxel. Among them, 2 in particular increased the sensitivity of KB-VIN cells to vincristine by 253-fold.

Alterations in sphingolipid composition and mitochondrial bioenergetics represent synergistic therapeutic vulnerabilities linked to multidrug resistance in leukemia.

Modifications in sphingolipid (SL) metabolism and mitochondrial bioenergetics are key factors implicated in cancer cell response to chemotherapy, including chemotherapy resistance. In the present work, we utilized acute myeloid leukemia (AML) cell lines, selected to be refractory to various chemotherapeutics, to explore the interplay between SL metabolism and mitochondrial biology supportive of multidrug resistance (MDR). In agreement with previous findings in cytarabine or daunorubicin resistant AML cells, relative to chemosensitive wildtype controls, HL-60 cells refractory to vincristine (HL60/VCR) presented with alterations in SL enzyme expression and lipidome composition. Such changes were typified by upregulated expression of various ceramide detoxifying enzymes, as well as corresponding shifts in ceramide, glucosylceramide, and sphingomyelin (SM) molecular species. With respect to mitochondria, despite consistent increases in both basal respiration and maximal respiratory capacity, direct interrogation of the oxidative phosphorylation (OXPHOS) system revealed intrinsic deficiencies in HL60/VCR, as well as across multiple MDR model systems. Based on the apparent requirement for augmented SL and mitochondrial flux to support the MDR phenotype, we explored a combinatorial therapeutic paradigm designed to target each pathway. Remarkably, despite minimal cytotoxicity in peripheral blood mononuclear cells (PBMC), co-targeting SL metabolism, and respiratory complex I (CI) induced synergistic cytotoxicity consistently across multiple MDR leukemia models. Together, these data underscore the intimate connection between cellular sphingolipids and mitochondrial metabolism and suggest that pharmacological intervention across both pathways may represent a novel treatment strategy against MDR.

Britannin, a sesquiterpene lactone induces ROS-dependent apoptosis in NALM-6, REH, and JURKAT cell lines and produces a synergistic effect with vincristine.

BACKGROUND: Britannin, a Sesquiterpene Lactone isolated from Inula aucheriana, has recently gained attraction in the therapeutic fields due to its anti-tumor properties. This study was designed to evaluate the effect of this agent on Acute Lymphoblastic Leukemia (ALL) cell lines, either as a monotherapy or in combination with Vincristine (VCR). METHODS AND RESULTS: To determine the anti-leukemic effects of Britannin on ALL-derived cell lines and suggest a mechanism of action for the agent, we used MTT assay, Annexin-V/PI staining, ROS assay, and real-time PCR analysis. Moreover, by using a combination index (CI), we evaluated the synergistic effect of Britannin on Vincristine. We found that unlike normal Peripheral Blood Mononuclear Cells (PBMCs) and L929 cells, Britannin reduced the viability of NALM-6, REH, and JURKAT cells. Among tested cells, NALM-6 cells had the highest sensitivity to Britannin, and this agent was able to induce p21/p27-mediated G1 cell cycle arrest and Reactive Oxygen Specious (ROS)-mediated apoptotic cell death in this cell line. When NALM-6 cells were treated with Nacetyl-L-Cysteine (NAC), a scavenger of ROS, Britannin could induce neither apoptosis nor reduce the survival of the cells suggesting that the cytotoxic effect of Britannin is induced through ROS-dependent manner. Moreover, we found that a low dose of Britannin enhanced the effect of Vincristine in NALM-6 cells by inducing apoptotic cell death via altering the expression of apoptotic-related genes. CONCLUSIONS: Overall, our results proposed a mechanism for the cytotoxic effect of Britannin, either as a single agent or in combination with Vincristine, in NALM-6 cells.

Development of a novel in vitro assay to screen for neuroprotective drugs against iatrogenic neurite shortening.

This work tries to help overcome the lack of relevant translational screening assays, as a limitation for the identification of novel analgesics for neuropathic pain. Hyperexcitability and neurite shortening are common adverse effects of antiviral and antitumor drugs, leading to neuropathic pain. Now, as seen in the drug screening that we developed here, a high-content microscopy-based assay with immortalized dorsal root ganglia (DRG) neurons (differentiated F11 cells) allowed to identify drugs able to protect against the iatrogenic neurite shortening induced by the antitumor drug vincristine and the antiviral drug rilpivirine. We observed that vincristine and rilpivirine induced a significant reduction in the neurite length, which was reverted by α-lipoic acid. We had also evidenced protective effects of pregabalin and melatonin, acting through the α2δ-2 subunit of the voltage-dependent calcium channels and the MT1 receptor, respectively. Additionally, two hits originated from a previous primary screening aimed to detect inhibitors of hyperexcitability to inflammatory mediators in DRG neurons (nitrendipine and felodipine) also prevented neurite shortening in our model. In summary, in this work we developed a novel secondary assay for identifying hits with neuroprotective effect against iatrogenic neurite shortening, consistent with the anti-hyperexcitability action previously tested: highlighting nitrendipine and felodipine against iatrogenic damage in DRG neurons.

Antitumor effects of curcumin in pediatric rhabdomyosarcoma in combination with chemotherapy and phototherapy in vitro.

Rhabdomyosarcoma (RMS), the most common pediatric soft tissue sarcoma, has an unfavorable outcome in advanced tumor stages with less than 30% failure­free survival. Curcumin (CUR) is a promising drug in complementary oncology with few side effects but proven efficacy in various adult oncological entities. The present study analyzed the effects of CUR on pediatric (RMS) cell lines in vitro. RMS cell lines (RD and RH30), and skeletal muscle cells (SKMC) were treated with different doses of CUR (1.5­30 µM) alone, with phototherapy (PDT, 488 nm) or in combination with vincristine (VCR) or dactinomycin (DAC). MTT assays were used for analysis of RMS tumor cell viability. Clonal cell growth was assessed via colony forming assays and migration of the cells was analyzed with scratch tests. Annexin V staining was used to determine apoptosis in flow cytometry. Possible RMS resistance towards CUR after long­term treatment was analyzed with MTT assays. CUR decreased cell viability in all assessed RMS cell lines in a concentration­dependent manner with IC50=14­20 µM. CUR enhanced the effects of the cytotoxic drugs VCR or DAC, and led to reduced migration and increased cell apoptosis. In combination with PDT, CUR decreased the cell viability in minute quantities with up to a 10­fold lower IC50 than without PDT. CUR effectively inhibited the malignant properties of pediatric RMS cells and should be focused on as a useful additional agent in standard chemotherapy of RMS in children.

Dihydromyricetin reverses MRP2-induced multidrug resistance by preventing NF-κB-Nrf2 signaling in colorectal cancer cell.

BACKGROUD: Dihydromyricetin (DMY), a natural flavonoid compound from the leaves of the Chinese medicinal herb Vitis heyneana, has been shown to have the potential to combat chemoresistance by inhibiting Nrf2/MRP2 signaling in colorectal cancer (CRC) cells. However, the precise underlying molecular mechanism and its therapeutic target are not well understood. PURPOSE: Our study aims to investigate the effects of DMY on multidrug resistance (MDR), and elucidate the underlying mechanisms. STUDY DESIGN: In vitro, HCT116/OXA and HCT8/VCR cells were employed as our MDR models. The cells were treated with DMY (50 µM) or MK-571 (50 µM) plus oxaliplatin (OXA) (10 µM) or vincristine (VCR) (10 µM) for 48 h. In vivo, we used BALB/c mice as a CRC xenograft mouse model. BALB/c mice were given DMY (100 mg/kg), OXA (5 mg/kg) and DMY (100 mg/kg) combined with OXA (5 mg/kg) via intraperitoneal route every 2 days per week for 4 weeks. METHODS: We used MTT and colony forming assays to detect DMY's ability to reverse MDR. Flow cytometric analysis was used to detect apoptosis. Immunocytochemistry was used to detect the localization of Nrf2 and NF-κB/p65. Western blot, qRT-PCR and reporter gene assays were employed to measure the protein and gene transcriptional levels (MRP2, Nrf2, NF-κB/p65). Moreover, chromatin immunoprecipitation (ChIP) assay was used to investigate the endogenous promoter occupancy of NF-κB/p65. Finally, immunohistochemistry and TUNEL staining were used to detect protein expression and apoptosis in vivo. RESULTS: DMY restored chemosensitivity (OXA and VCR) by inhibiting both MRP2 expression and its promoter activity in HCT116/OXA and HCT8/VCR cell lines. Furthermore, DMY could inhibit NF-κB/p65 expression, reducing NF-κB/p65 translocation to the nucleus to silence Nrf2 signaling, which is necessary for MRP2 expression. Overexpressing NF-κB/p65 expression reduced the reversal effect of DMY. In addition, NF-κB/p65 regulated Nrf2 expression by directly binding to its specific promoter region and activating its transcription. Finally, we proved that the combination of OXA and DMY has a synergistic tumor suppression effect in vivo. CONCLUSION: Our study provided a novel mechanism of DMY boosted chemosensitivity in human CRC. The downstream signals of DMY, NF-κB or Nrf2 could also be potential targets for the treatment of CRC.

Overcoming vincristine resistance in cancer: Computational design and discovery of piperine-inspired P-glycoprotein inhibitors.

P-glycoprotein (P-gp)/MDR-1 plays a major role in the development of multidrug resistance (MDR) by pumping the chemotherapeutic drugs out of the cancer cells and reducing their efficacy. A number of P-gp inhibitors were reported to reverse the MDR when co-administered with chemotherapeutic drugs. Unfortunately, none has approved for clinical use due to toxicity issues. Some of the P-gp inhibitors tested in the clinics are reported to have cross-reactivity with CYP450 drug-metabolizing enzymes, resulting in unpredictable pharmacokinetics and toxicity of co-administered chemotherapeutic drugs. In this study, two piperine analogs (3 and 4) having lower cross-reactivity with CYP3A4 drug-metabolizing enzyme are identified as P-glycoprotein (P-gp) inhibitors through computational design, followed by synthesis and testing in MDR cancer cell lines over-expressing P-gp (KB ChR 8-5, SW480-VCR, and HCT-15). Both the analogs significantly increased the vincristine efficacy in MDR cancer cell lines at low micromole concentrations. Specifically, 3 caused complete reversal of vincristine resistance in KB ChR 8-5 cells and found to act as competitive inhibitor of P-gp as well as potentiated the vincristine-induced NF-KB-mediated apoptosis. Therefore, 3 ((2E,4E)-1-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)-5-(4-hydroxy-3-methoxyphenyl)penta-2,4-dien-1-one) can serve as a potential P-gp inhibitor for in vivo investigations, to reverse multidrug resistance in cancer.

Will Baseline Total Lesion Glycolysis Play a Role in Improving the Prognostic Value of the NCCN-IPI in Primary Gastric Diffuse Large B-Cell Lymphoma Patients Treated With the R-CHOP Regimen?

PURPOSE: The aim was to explore whether baseline total lesion glycolysis (TLG) can improve the prognostic value of the National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) in primary gastric diffuse large B-cell lymphoma (PG-DLBCL) patients treated with an R-CHOP-like regimen. MATERIALS AND METHODS: Ninety-four PG-DLBCL patients who underwent baseline PET/CT between July 2010 and May 2019 were included in this retrospective study. FDG-avid lesions in each patient were segmented to calculate the SUVmax, total metabolic tumor volume (TMTV), and TLG. Progression-free survival (PFS) and overall survival (OS) were used as end points to evaluate prognosis. RESULTS: During the follow-up period of 5 to 108 months (35.3 ± 23.5 months), high TLG and a high NCCN-IPI were significantly associated with poor PFS and OS. Total lesion glycolysis and the NCCN-IPI were independent predictors of PFS and OS. Patients were stratified into 3 groups according to the combination of TLG and the NCCN-IPI for PFS (P < 0.001) and OS (P < 0.001): high-risk group (TLG > 1159.1 and NCCN-IPI 4-8) (PFS and OS, 57.7% and 61.5%, respectively, n = 42), intermediate-risk group (TLG > 1159.1 or NCCN-IPI 4-8) (PFS and OS, both 76.9%, n = 26), and low-risk group (TLG ≤ 1159.1 and NCCN-IPI 0-3) (PFS and OS, 97.6% and 100.0%, respectively, n = 26). CONCLUSIONS: Both TLG and the NCCN-IPI are independent predictors of PG-DLBCL patient survival. Moreover, the combination of TLG and the NCCN-IPI improved patient risk stratification and might help personalize therapeutic regimens.

Calliandra portoricensis ameliorates ovarian and uterine oxido-inflammatory responses in N-methyl-N-nitrosourea and benzo[a]pyrene-treated rats.

IMPACT STATEMENT: Infertility resulting from reproductive impairment is traumatic in families. Exposure to chemicals may play insidious roles not easily connected to infertility. We examined benzo[a]pyrene (BaP), and N-methyl nitrosourea (NMU)-induced ovarian and uterine toxicity and the role of Calliandra portoricensis in mitigating toxicity. In a bid to illuminate folk medical claims cloaked in mystery, unearthing lost knowledge, advance natural chemopreventive agents, and report new evidence lacking in the literature attributed to CP. Although CP is known to exhibit anticonvulsant, antidiarrheal, antipyretic, antirheumatic, and analgesic effects in humans, its possible roles for mitigating toxicity stemming from inadvertent chemical exposures are reported here. Our findings affirm and further show that CP abates toxic response incumbent on oxidative damage and inflammatory responses associated with NMU and BaP exposure. Development of phytochemical derived from CP may serve as a potential natural therapy against chemical toxicities in individuals inadvertently exposed, and promote human health and reproductive satiety.

Fomes fomentarius and Tricholoma anatolicum (Agaricomycetes) Extracts Exhibit Significant Multiple Drug-Resistant Modulation Activity in Drug-Resistant Breast Cancer Cells.

Multiple drug resistance is one of the main problems that hinder successful cancer chemotherapy. Investigations on the development of effective chemotherapeutic agents and drug resistance inhibitors motivate studies on the effects of natural compounds on drug-resistant cancer cells. For this purpose, aqueous, methanol, and ethanol extracts of Fomes fomentarius and Tricholoma anatolicum were prepared. The extracts were evaluated to assess their anticancer and multiple drug resistance modulation activities. Cytotoxic effects of F. fomentarius and T. anatolicum extracts on paclitaxel and vincristine resistant P-glycoprotein over-expressing MCF-7 cell lines were investigated by cytotoxicity test (XTT). P-glycoprotein reversing ability and MDR modulation effects of the extracts were determined by flow cytometry through Rhodamine 123 exclusion assay. Furthermore, 11 phenolic compounds in the extracts were characterized by HPLC. As a result of the cytotoxicity assay, IC50 values of the extracts for MCF-7/Vinc were between 1.08 and 1.80 mg/mL, and IC50 values for MCF-7/Pac were found between 1.11 and 2.83 mg/mL. Strikingly, methanol extract of F. fomentarius and ethanol extract of T. anatolicum have potential value to become MDR reversing agents for drug-resistant breast cancer cells.

Bousangine A, a novel C-17-nor aspidosperma-type monoterpenoid indole alkaloid from Bousigonia angustifolia.

Two new monoterpenoid indole alkaloids, bousangines A (1) and B (2), were isolated from the twigs and leaves of Bousigonia angustifolia. Their structures including absolute configurations were elucidated by a combination of MS, NMR, ECD calculation, and single-crystal X-ray diffraction analysis. Bousangine A (1) possessed a rearrangement pentacyclic skeleton derived from aspidosperma-type alkaloids with C-17 degradation. Their antiproliferative activity against several human cancer cell lines were evaluated.

Ergolide, a potent sesquiterpene lactone induces cell cycle arrest along with ROS-dependent apoptosis and potentiates vincristine cytotoxicity in ALL cell lines.

ETHNOPHARMACOLOGICAL RELEVANCE: Inula oculus christi belongs to the family of Asteraceae and it was traditionally wide used in treatment of kidney stones and urethra infection; besides, recently the potent sesquiterpene lactones isolated from inula species has gained increasing attention in cancer treatments. This study investigates the anti-cancer properties and underlying mechanism of ergolide isolated from Inula oculus christi against leukemic cell lines. METHODS: Viability, metabolic activity and proliferation evaluated using different index of MTT assay such as IC50 and GI50. Human erythrocytes were used to evaluate hemolytic activity. Flow-cytometry was used to detect and measure ROS level, and the induction of apoptosis and autophagy were evaluated using Annexin V/PI, Acridine Orange staining, respectively. Moreover, qRT-PCR was performed to examine the expression of a large cohort of crucial regulatory genes. Tunel assay was also carried out to assess morphologically ergolide effects. RESULTS: Ergolide did not exert ant cytotoxicity against non-tumorous cells and did not cause noticeable hemolysis. It also caused ROS production during early hours after treatment of cells which was then followed by cell cycle arrest in G0/G1 phase and autophagy induction. Using N-acetyl-L-cysteine (NAC), we found that ergolide could not increase ROS and induce autophagy and moreover repressed cell death, indicating that ergolide induce cell death through ROS-dependent manner by altering the expression of pro apoptotic related genes. Autophagy inhibition also potentiated ergolide-induced cell death. Furthermore, ergolide intensified vincristine cytotoxicity against acute lymphoblastic leukemia (ALL) cell lines revealed robust synergistic properties of ergolide with VCR. CONCLUSION: Here we showed that ergolide could be considered as a potent natural compound against leukemic cells by inducing cell cycle arrest followed by dose-dependent cell death. Based on results, Autophagy response in a result of ROS accumulation acted as a survival pathway and blocking this pathway could noticeably increase ergolide cytotoxicity on ALL cell lines.

Pain attenuating actions of vincristinet-preconditioning in chemotherapeutic agent-induced neuropathic pain: key involvement of T-type calcium channels.

Preconditioning is a well-documented strategy that induces hepatic protection, renal protection, cardioprotection, and neuroprotection but its mechanism still remains to be elucidated. Hence, the present study investigated the protective mechanism underlying pain attenuating effects of vincristine-preconditioning in chemotherapeutic agent-induced neuropathic pain. Neuropathic pain was induced by administration of vincristine (50 µg/kg, i.p.) for 10 days in rats. Vincristine-preconditioning was induced by administration of vincristine (2, 5, and 10 µg/kg, i.p) for 5 days before administration of pain-inducing dose of vincristine (50 µg/kg, i.p.). Vincristine-preconditioning (10 µg/kg, i.p) for 5 days significantly reduced vincristine (50 µg/kg, i.p.) induced pain-related behaviors including paw cold allodynia, mechanical hyperalgesia, and heat hyperalgesia. However, vincristine (2 and 5 µg/kg, i.p) did not significantly ameliorate the vincristine (50 µg/kg, i.p.) induced neuropathic pain in rats. Furthermore, to explore the involvement of calcium channels in pain attenuating mechanism of vincristine-preconditioning, T-type calcium channel blocker, ethosuximide (100 and 200 mg/kg, i.p.) and L-type calcium channel blocker, amlodipine (5 and 10 mg/kg, i.p.) were used. Pretreatment with T-type calcium channel blocker, ethosuximide significantly abolished vincristine-preconditioning-induced protective effect. However, pretreatment with L-type calcium channel blocker, amlodipine did not alter vincristine-preconditioning-induced pain-related behaviors. This indicates that vincristine-preconditioning has protective effect on pain-related parameters due to opening of calcium channels, particularly T-type calcium channels that lead to entry of small magnitude of intracellular calcium through these channels and prevent the deleterious effects of high-dose vincristine.

Effect of Arrabidaea chica extract against chemically induced breast cancer in animal model.

PURPOSE: To examine the effects of Arrabidaa chica (Bignoniacea) extract, a native plant of the Amazon known as crajiru, on a 7,12-dimethyl-1,2-benzanthracene (DMBA)-induced breast cancer model in Wistar rats. METHODS: We compared the response of breast cancer to the oral administration of A. chica extract (ACE) for 16 weeks, associated or not with vincristine. Groups: normal control; DMBA (50mg/kg v.o,) without treatment; DMBA+ACE (300 mg/kg); DMBA+vincristine. 500µg/kg injected i.p; DMBA+ACE+Vincristine 250µg/kg i.p. Imaging by microPET and fluorescence, biochemistry, oxidative stress, hematology and histopathology were used to validate the treatments. RESULTS: All animals survived. A gradual weight gain in all groups was observed, with no significant difference (p>0.05). The oral administration of ACE and ACE+vincristine 50% significantly reduced breast tumors incidence examined with PET-18FDG and fluorescence (p<0.001). Significant reduction of serum transaminases, oxidative stress and hematological toxicity were observed in these groups. Antioxidant enzyme levels in breast tissue were significantly higher compared to the DMBA and DMBA+vincristine groups. CONCLUSION: These results demonstrate for the first time that ACE positively influences the treatment of DMBA-induced breast cancer in animal model, inducing a reduction in oxidative stress and chemotherapy toxicity, meaning that ACE may have clinical implication in further studies.

Effect of Arrabidaea chica extract against chemically induced breast cancer in animal model

Abstract Purpose: To examine the effects of Arrabidaa chica (Bignoniacea) extract, a native plant of the Amazon known as crajiru, on a 7,12-dimethyl-1,2-benzanthracene (DMBA)-induced breast cancer model in Wistar rats. Methods: We compared the response of breast cancer to the oral administration of A. chica extract (ACE) for 16 weeks, associated or not with vincristine. Groups: normal control; DMBA (50mg/kg v.o,) without treatment; DMBA+ACE (300 mg/kg); DMBA+vincristine. 500μg/kg injected i.p; DMBA+ACE+Vincristine 250μg/kg i.p. Imaging by microPET and fluorescence, biochemistry, oxidative stress, hematology and histopathology were used to validate the treatments. Results: All animals survived. A gradual weight gain in all groups was observed, with no significant difference (p>0.05). The oral administration of ACE and ACE+vincristine 50% significantly reduced breast tumors incidence examined with PET-18FDG and fluorescence (p<0.001). Significant reduction of serum transaminases, oxidative stress and hematological toxicity were observed in these groups. Antioxidant enzyme levels in breast tissue were significantly higher compared to the DMBA and DMBA+vincristine groups. Conclusion: These results demonstrate for the first time that ACE positively influences the treatment of DMBA-induced breast cancer in animal model, inducing a reduction in oxidative stress and chemotherapy toxicity, meaning that ACE may have clinical implication in further studies.

Celastrol induces vincristine multidrug resistance oral cancer cell apoptosis by targeting JNK1/2 signaling pathway.

BACKGROUND: Oral cancers are one of the most aggressive malignancies, with high mortality rates globally. Patients with these cancers are treated using combination therapies including surgery, chemotherapy, and radiotherapy. HYPOTHESIS/PURPOSE: Traditional Chinese medicines and other herbal medicines have been used to treat various diseases in Asia. Celastrol is a pentacyclic triterpenoid isolated from the Chinese herbal medicine Trypterygium wilfordii, which has therapeutic potential in multiple diseases. The present study was to determine the effect of celastrol on vincristine-resistant cancer cell line and to illuminate the mechanism of celastrol-induced cell apoptosis. STUDY DESIGN: Celastrol was added to vincristine-resistant cancer cell and immunoreactive proteins were detected. METHODS AND RESULTS: Our study demonstrated that celastrol leads to apoptosis of head and neck cancer cells through mitochondria- and Fas-mediated pathways. However, whether this herbal medicine exhibits beneficial effects on vincristine-resistant oral cancer patients remains uncertain. Therefore, our study examined the apoptotic effect exerted by celastrol and the mechanism by this drug acts on a vincristine-resistant cancer cell line. The present study demonstrated that celastrol triggered apoptotic cell death by inducing cell cycle arrest at the G2/M phase via the intrinsic and extrinsic pathways (increased cleaved caspase-3, caspase-8, caspase-9, and PARP). Increased expression of tBid also indicated the presence of crosstalk between the two pathways. Celastrol mediated cell apoptosis through the downregulation of the expression of Bcl-2, not Bcl-xL. Moreover, JNK1/2 signaling was the main pathway of celastrol-induced apoptosis. CONCLUSION: Celastrol could become a useful agent for treating oral cancers with MDR.

Saponins of Tribulus terrestris attenuated neuropathic pain induced with vincristine through central and peripheral mechanism.

The study comprises exploring the effects of saponins from Tribulus terrestris (TT) in attenuating the neuropathic pain caused by vincristine (100 µg/ml i.p.) for 10 days (in two 5 day cycles with 2 days pause). Mechanical hyperalgesia and allodynia were assessed by Randall-Sellitto and electronic von Frey tests, respectively. Chemical- induced nociception was assessed by formalin test. Neurophysiological effect of the extract was evaluated by recording sciatic functional index (SFI) on the test days (7, 10, 14, and 21) and sciatic nerve conduction velocity test (SNCV) on the last day. Inflammatory mediators (TNF-α, IL-1ß, and IL-6) in both sciatic nerve and brain and brain neurotransmitters, glutamate and aspartate, were measured to support the behavioral response. The saponins of TT-treated group were found to be effective in the behavioral experiments, implying its activity both centrally and peripherally in attenuating pain. The inflammatory mediators in both sciatic nerve and brain (TNF-α, IL-1ß, and IL-6) were found to be attenuated with TT saponin treatment in comparison to vincristine-treated group, indicating its anti-inflammatory property. The excitatory neurotransmitters, L-glutamic acid and L-aspartic acid, were also found to be attenuated with TT saponins, implying restoration of neuronal damage and synaptic activity caused by high amount of glutamate due to excess TNF-α in brain and reversing the nociceptive threshold lowered due to aspartate. Thus, TT(S) is peripherally and centrally active in lowering the inflammatory mediators, reversing the neuronal damage and increasing the nociceptive threshold caused due to peripheral neuropathy.