Cytotoxic effects of loperamide hydrochloride on canine cancer cells

Loperamide induces protective autophagy and apoptosis through the ROS/JNK signaling pathway in bladder cancer

Bladder cancer is one of the most common carcinomas in the human urinary system worldwide. Loperamide, known as an antidiarrheal drug, exerts anti-tumor activities against various cancers. However, the effect of loperamide on bladder cancer cells remains unclear. Our study aimed to investigate the effect of loperamide on bladder cancer and explore the underlying mechanisms. We found that loperamide suppressed the proliferation of 5637 and T24 cells in a dose-dependent manner. Loperamide treatment showed both pro-apoptotic and pro-autophagic effects on bladder cancer cells. Moreover, it was revealed that loperamide induced reactive oxygen species (ROS) accumulation, leading to the activation of c-Jun N-terminal kinase (JNK) signaling pathway. Notably, ROS scavenger N-acetyl-L-cysteine (NAC) and JNK inhibitor SP600125 effectively attenuated the induction of autophagy and apoptosis triggered by loperamide. Finally, blocking autophagy with CQ could significantly enhance the anti-cancer effect of loperamide both in vitro and in vivo. Overall, these findings demonstrated that loperamide induced autophagy and apoptosis through the ROS-mediated JNK pathway in bladder cancer cells. Our results suggest that the strategy of combining loperamide with autophagy inhibitor CQ may provide a therapeutic option for the treatment of bladder cancer.

Antidiarrheal and antioxidant activities of Ajuga iva (L.) leave extract

We studied the effect of Ajuga iva leaves extract (AIE) on the intestinal absorption, motricity and its antioxidant capacity against diarrhea. Wistar rats were divided and received either: castor oil (CO), CO and loperamide or CO and different doses of AIE. AIE prevented dose-dependently CO-induced diarrhea. AIE at 800 mg/kg showed inhibition efficiency on defecation and diarrhea. The pro-oxidant effect of the CO in the small intestine was inhibited significantly in presence of AIE: increasing glutathione peroxidase (GPx) activity and lowering oxygen free radicals (OH°, O2°-), carbonyl protein and malondialdehyde (MDA) levels. However, co-administration of AIE in castor oil-exposed groups significantly increased the intestinal contents of calcium and magnesium. AIE exhibits significant anti-diarrheal activity, related in part to its antioxidant properties. Our investigation also provides experimental evidence for the traditional use of this medicinal plant in the treatment of diarrhea.

Assessment in vitro of interactions between anti-cancer drugs and noncancer drugs commonly used by cancer patients

Cancer patients often suffer from cancer symptoms, treatment complications and concomitant diseases and are, therefore, often treated with several drugs in addition to anticancer drugs. Whether such drugs, here denoted as 'concomitant drugs', have anticancer effects or interact at the tumor cell level with the anticancer drugs is not very well known. The cytotoxic effects of nine concomitant drugs and their interactions with five anti-cancer drugs commonly used for the treatment of colorectal cancer were screened over broad ranges of drug concentrations in vitro in the human colon cancer cell line HCT116wt. Seven additional tyrosine kinase inhibitors were included to further evaluate key findings as were primary cultures of tumor cells from patients with colorectal cancer. Cytotoxic effects were evaluated using the fluorometric microculture cytotoxicity assay (FMCA) and interaction analysis was based on Bliss independent interaction analysis. Simvastatin and loperamide, included here as an opioid agonists, were found to have cytotoxic effects on their own at reasonably low concentrations whereas betamethasone, enalapril, ibuprofen, metformin, metoclopramide, metoprolol and paracetamol were inactive also at very high concentrations. Drug interactions ranged from antagonistic to synergistic over the concentrations tested with a more homogenous pattern of synergy between simvastatin and protein kinase inhibitors in HCT116wt cells. Commonly used concomitant drugs are mostly neither expected to have anticancer effects nor to interact significantly with anticancer drugs frequently used for the treatment of colorectal cancer.

Identification and validation of a five-lncRNA signature for predicting survival with targeted drug candidates in ovarian cancer

The dysregulation of long non-coding RNAs (lncRNAs) plays a crucial role in ovarian cancer (OC). In this study, we screened out five differentially expressed lncRNAs (AC092718.4, AC138035.1, BMPR1B-DT, RNF157-AS1, and TPT1-AS1) between OC and normal ovarian based on TCGA and GTEx RNA-seq databases by using Kaplan-Meier analysis and univariate Cox, LASSO, and multivariate Cox regression. Then, a risk signature was constructed, with 1, 3, 5-year survival prediction accuracy confirmed by ROC curves, and an online survival calculator for easier clinical use. With lncRNA-microRNA-mRNA regulatory networks established, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed, suggesting the involvement of a variety of cancer-related functions and pathways. Finally, five candidate small-molecule drugs (thioridazine, trifluoperazine, loperamide, LY294002, and puromycin) were predicted by Connectivity Map. In conclusion, we identified a 5-lncRNA signature of prognostic value with its ceRNA networks, and five candidate drugs against OC.[Figure: see text].

DARK Classics in Chemical Neuroscience: Loperamide

Loperamide, a popular and inexpensive over-the-counter antidiarrheal medicine, is a potent μ-opioid receptor agonist approved by the U.S. Food and Drug Administration (FDA). It has been on the market since 1976 and is relatively safe with no central nervous system-related side effects when used for a short period of time at the recommended therapeutic dose (2-8 mg/day). In recent years, loperamide has become notoriously known as the "poor man's methadone" for people with substance dependence due to the increase in loperamide overdoses from self-administered medication to treat opioid withdrawal symptoms. As a result, in 2018, the FDA decided to limit the available packaged dose of loperamide to stop prominent abuse. This review provides the synthesis and chemical properties of loperamide as well as the pharmacology and adverse effects of its use and the social effects of such abuse.

Future Oncotargets: Targeting Overexpressed Conserved Protein Targets in Androgen Independent Prostate Cancer Cell Lines

BACKGROUND

Targeting evolutionarily conserved proteins in malignant cells and the adapter proteins involved in signalling that generates from such proteins may play a cardinal role in the selection of anti-cancer drugs. Drugs targeting these proteins could be of importance in developing anti-cancer drugs.

OBJECTIVES

We inferred that drugs like loperamide and promethazine that act as antagonists of proteins conserved in cancer cells like voltage-gated Calcium channels (Cav), Calmodulin (CaM) and drug efflux (ABCB1) pump may have the potential to be re-purposed as an anti-cancer agent in Prostate Cancer (PCa).

METHODS

Growth and cytotoxic assays were performed by selecting loperamide and promethazine to target Cav, CaM and drug efflux (ABCB1) pumps to elucidate their effects on androgen-independent PC3 and DU145 PCa cell lines.

RESULT

We show that loperamide and promethazine in doses of 80-100μg/ml exert oncocidal effects when tested in DU145 and PC3 cell lines. Diphenhydramine, which shares its targets with promethazine, except the CaM, failed to exhibit oncocidal effects.

CONCLUSION

Anti-cancer effects can be of significance if structural analogues of loperamide and promethazine that specifically target Cav, CaM and ABCB1 drug efflux pumps can be synthesized, or these two drugs could be re-purposed after human trials in PCa.

A Comparative Study of Cluster Detection Algorithms in Protein-Protein Interaction for Drug Target Discovery and Drug Repurposing

The interactions between drugs and their target proteins induce altered expression of genes involved in complex intracellular networks. The properties of these functional network modules are critical for the identification of drug targets, for drug repurposing, and for understanding the underlying mode of action of the drug. The topological modules generated by a computational approach are defined as functional clusters. However, the functions inferred for these topological modules extracted from a large-scale molecular interaction network, such as a protein–protein interaction (PPI) network, could differ depending on different cluster detection algorithms. Moreover, the dynamic gene expression profiles among tissues or cell types causes differential functional interaction patterns between the molecular components. Thus, the connections in the PPI network should be modified by the transcriptomic landscape of specific cell lines before producing topological clusters. Here, we systematically investigated the clusters of a cell-based PPI network by using four cluster detection algorithms. We subsequently compared the performance of these algorithms for target gene prediction, which integrates gene perturbation data with the cell-based PPI network using two drug target prioritization methods, shortest path and diffusion correlation. In addition, we validated the proportion of perturbed genes in clusters by finding candidate anti-breast cancer drugs and confirming our predictions using literature evidence and cases in the ClinicalTrials.gov. Our results indicate that the Walktrap (CW) clustering algorithm achieved the best performance overall in our comparative study.

β Lapachone blocks the cell cycle and induces apoptosis in canine osteosarcoma cells

ABSTRACT: Osteosarcoma is a malignant tumor of primitive bone cells with a high incidence in dogs and humans. The need for more effective drugs with less adverse consequences has pushed the development of chemotherapeutic agents from plants and other natural sources. The aim of this study was to verify the cytotoxic effects of β-lapachone, a compound present in the sawdust of Tabebuia sp. (popularly known as ipê) wood, on canine osteosarcoma cells subcultured and treated in different concentrations (0.1μm, 0.3μm e 1.0μm) and exposure times (24h, 48h e 72h). Results were obtained through Trypan blue dye exclusion, tetrazolium reducing method, cell survival assay, Annexin V-FITC and Propidium Iodine labeling, JC-1 dye labeling and cell cycle kinetics e analysis. The group treated with 0.3μm β-lapachone presented higher decrease in cell viability (80.27%, 24h, 47.41%, 48h and 35.19%, 72h) and greater progression of cytotoxicity (19.73%, 24h, 52.59%, 48h and 64.81%, 72h). The lower IC50 (0.180μm) was verified in the group treated for 72 hours. Cell growth after treatment decreased as concentration and time of exposure increased, with 0.50% survival fraction at the concentration of 1.0μm. Initial apoptosis was the most frequent type of cell death in all groups, reaching bottom in the 24-hour group treated with 0.1μm (4.26%) and peaking in the 72-hour group treated with 1.0μm (85.89%). Mitochondrial depolarization demonstrated a dose-dependent phenomenon, indicating the intrinsic apoptosis. Cell growth inhibition by blocking cell cycle in the G0/G1 phase related to the exposure the time. β-lapachone is cytotoxic for canine osteosarcoma cells, induces apoptosis and promotes cell cycle arrest in G0/G1 phase.

Loperamide, an antidiarrheal agent, induces apoptosis and DNA damage in leukemia cells

Loperamide, an antidiarrheal agent, is frequently used to treat patients with leukemia with symptoms of diarrhea during treatment. However, the effect of loperamide on leukemia cells is unknown. The MTT assay was used to explore the cytotoxic effect of loperamide on leukemia cells. Morphological analysis and flow cytometry were performed to determine the level of apoptosis in leukemia cells following loperamide treatment. Western blotting was conducted to test the activation of the apoptotic pathway. The comet assay was used to determine the DNA damage induced by loperamide. Loperamide potently inhibited the proliferation of leukemia cell lines and primary leukemia cells from 9 patients with acute myeloid leukemia (AML) and 6 patients with acute lymphocytic leukemia (ALL) in a dose-dependent manner. Loperamide increased the expression of cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase, decreased the expression of myeloid cell lekeumia-1 and induced the apoptosis of leukemia cells. In addition, treatment with 20 µM loperamide increased the expression level of the protein rH2ax and promoted the formation of long DNA comet tails, thus triggering DNA damage in leukemia cells. Finally, DNA damage was confirmed by the activation of the ataxia telangiectasia mutated serine/threonine kinase (ATM)-checkpoint kinase 2 (Chk2) signaling pathway. The phosphorylation level of ATM (Ser1981) and Chk2 (Thr68) was activated and upregulated following DNA damage triggered by loperamide. Loperamide was demonstrated to perform an inhibitory role in the growth of leukemia cell lines and primary leukemia cells. Of note, apoptosis and DNA damage were induced following loperamide treatment in leukemia cell lines and primary leukemia cells.