Phyllanthus niruri Linn.: Antibacterial Activity, Phytochemistry, and Enhanced Antibiotic Combinatorial Strategies.

Antimicrobial resistance (AMR) is a global public health threat caused by the misuse and overuse of antibiotics. It leads to infections becoming difficult to treat, causing serious illness, disability, and death. Current antibiotic development is slow, with only 25% of current antibiotics exhibiting novel mechanisms against critical pathogens. Traditional medicinal plants' secondary metabolites offer potential for developing novel antibacterial compounds. These compounds, often with strong antimicrobial activity, can be used to develop safe and effective antibacterial chemotherapies. This study investigated the antibacterial activity of Phyllanthus niruri Linn. extracts against a panel of bacterial pathogens using disc diffusion and microdilution assays and quantified by calculation of minimum inhibition concentration (MIC). Additionally, the effects of combinations of the extracts and selected conventional antibiotics were examined by sum of fractional inhibition concentration (Æ©FIC) calculation and isobologram analysis. Liquid chromatography-mass spectrometry (LC-MS) phytochemistry analysis was used to identify noteworthy compounds in the active extracts and the Artemia nauplii bioassay was used to evaluate toxicity. The aqueous and methanolic extracts exhibited notable antibacterial activity in the broth microdilution assay against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) (MIC = 669 µg/mL and 738 µg/mL, respectively). The methanolic extract also showed noteworthy antibacterial action in the broth assay against Klebsiella pneumoniae (MIC = 738 µg/mL). The aqueous extract had noteworthy growth inhibitory activity against Bacillus cereus (MIC = 669 µg/mL), whilst the methanolic extract demonstrated good antibacterial activity against that bacterium (MIC = 184 µg/mL). The aqueous and methanol extracts showed minimal antibacterial action against Shigella flexneri and Shigella sonnei. The extracts were subjected to LC-MS analysis, which revealed several interesting phytochemicals, including a variety of flavonoids and tannins. The antibacterial activity and lack of toxicity of the P. niruri extracts indicates that they may be worthwhile targets for antibiotic development and further mechanistic and phytochemistry studies are required.

LAG-3 : recent developments in combinational therapies in cancer.

The study of anticancer immune responses and in particular the action of immune checkpoint inhibitors that overcome T cell inhibition has revolutionized metastatic patients' care. Unfortunately, many patients are resistant to these innovative immunotherapies. Over the last decade, several immune checkpoint inhibitors, currently available in the clinic, have been developed, such as anti-PD-1/PD-L1 or anti-CTLA-4. More recently, other immune checkpoints have been characterized, among them lymphocyte activation gene 3 (LAG-3). LAG-3 has been the subject of numerous therapeutic studies and may be involved in cancer-associated immune resistance phenomena. This review summarizes the latest knowledge on LAG-3 as an immunotherapeutic target, particularly in combination with standard or innovative therapies. Indeed, many studies are looking at combining LAG-3 inhibitors with chemotherapeutic, immunotherapeutic, radiotherapeutic treatments, or adoptive cell therapies to potentiate their antitumor effects and/or to overcome patients' resistance. We will particularly focus on the association therapies that are currently in phase III clinical trials and innovative combinations in preclinical phase. These new discoveries highlight the possibility of developing other types of therapeutic combinations currently unavailable in the clinic, which could broaden the therapeutic spectrum of personalized medicine.

Cancer Vaccine in Cold Tumors: Clinical Landscape, Challenges, and Opportunities.

The idea of cancer immunotherapy is to stimulate the immune system to fight tumors without destroying normal cells. One of the anticancer therapy methods, among many, is based on the use of cancer vaccines that contain tumor antigens in order to induce immune responses against tumors. However, clinical trials have shown that the use of such vaccines as monotherapy is ineffective in many cases since they do not cause a strong immune response. Particular tumors are resistant to immunotherapy due to the absence or insufficient infiltration of tumors with CD8+ T cells, and hence, they are called cold or non-inflamed tumors. Cold tumors are characterized by a lack of CD8+ T cell infiltration, the presence of anti-inflammatory myeloid cells, tumor-associated M2 macrophages, and regulatory T cells. It is very important to determine the stage of the antitumor response that does not work properly in order to use the right strategy. Applying other therapeutic methods alongside cancer vaccines can be more rational for cold tumors, which do not provoke the immune system strongly. Herein, we indicate some combinational therapies that have been used or are in progress for cold tumor treatment alongside vaccines.

Therapeutic potential of CAR T cell in malignancies: A scoping review.

Although tremendous advancements in cancer therapy over the last several years, cancer still is a complex illness to cure. Traditional cancer treatments, including chemotherapy, radiotherapy, and surgery, have a poor therapeutic effect, emphasizing the significance of employing innovative treatments like activated cell therapy. Chimeric antigen receptor T cell is one of the most prevalent types of activated cell therapy have been developed to direct T lymphocytes toward cancers (CAR-T cells). CAR-T cells therapy has illustrated poor impact versus solid tumors despite the remarkable success in patients suffering from hematological malignancies. CAR-T cells must overcome various hurdles to obtain full responses to solid tumors, including growth, stability, trafficking, and destiny inside tumors. As a result, novel treatment methods will entail overcoming the challenges that CAR-T cells face in solid tumors. The use of CAR-T cells in combination with other therapeutic approaches such as chemotherapy, radiotherapy, immuno-checkpoint inhibitors, and oncolytic viruses can promote the effectiveness of CAR-T cell therapy for the treatment of solid tumors. However, more research is needed to determine the safety and effectiveness of these therapies. CAR-T cell treatment success rates vary by type of disease, but are predicted to reach up to 90% in patients with leukemia. However, since this kind of immunotherapy is still in its infancy, there is much to learn about its efficacy. This review provided an in-depth examination of CAR-T cell therapy and its success and failure as a cancer treatment approach. We also discuss combination therapies with CAR-T Cell.

Novel carfilzomib-based combinations as potential therapeutic strategies for liposarcomas.

Proteasome inhibitors, such as bortezomib and carfilzomib, have shown efficacy in anti-cancer therapy in hematological diseases but not in solid cancers. Here, we found that liposarcomas (LPS) are susceptible to proteasome inhibition, and identified drugs that synergize with carfilzomib, such as selinexor, an inhibitor of XPO1-mediated nuclear export. Through quantitative nuclear protein profiling and phospho-kinase arrays, we identified potential mode of actions of this combination, including interference with ribosome biogenesis and inhibition of pro-survival kinase PRAS40. Furthermore, by assessing global protein levels changes, FADS2, a key enzyme regulating fatty acids synthesis, was found down-regulated after proteasome inhibition. Interestingly, SC26196, an inhibitor of FADS2, synergized with carfilzomib. Finally, to identify further combinational options, we performed high-throughput drug screening and uncovered novel drug interactions with carfilzomib. For instance, cyclosporin A, a known immunosuppressive agent, enhanced carfilzomib's efficacy in vitro and in vivo. Altogether, these results demonstrate that carfilzomib and its combinations could be repurposed for LPS clinical management.

Midkine signaling maintains the self-renewal and tumorigenic capacity of glioma initiating cells.

Glioblastoma (GBM) is one of the most aggressive forms of cancer. It has been proposed that the presence within these tumors of a population of cells with stem-like features termed Glioma Initiating Cells (GICs) is responsible for the relapses that take place in the patients with this disease. Targeting this cell population is therefore an issue of great therapeutic interest in neuro-oncology. We had previously found that the neurotrophic factor MIDKINE (MDK) promotes resistance to glioma cell death. The main objective of this work is therefore investigating the role of MDK in the regulation of GICs. Methods: Assays of gene and protein expression, self-renewal capacity, autophagy and apoptosis in cultures of GICs derived from GBM samples subjected to different treatments. Analysis of the growth of GICs-derived xenografts generated in mice upon blockade of the MDK and its receptor the ALK receptor tyrosine kinase (ALK) upon exposure to different treatments. Results: Genetic or pharmacological inhibition of MDK or ALK decreases the self-renewal and tumorigenic capacity of GICs via the autophagic degradation of the transcription factor SOX9. Blockade of the MDK/ALK axis in combination with temozolomide depletes the population of GICs in vitro and has a potent anticancer activity in xenografts derived from GICs. Conclusions: The MDK/ALK axis regulates the self-renewal capacity of GICs by controlling the autophagic degradation of the transcription factor SOX9. Inhibition of the MDK/ALK axis may be a therapeutic strategy to target GICs in GBM patients.

Ascorbic acid potentiates the Giardia duodenalis growth inhibitory activity of pure Terminalia ferdinandiana Exell compounds.

Giardiasis, one of the most common causes of diarrhoeal disease, is caused by gastrointestinal protozoal parasites of the genus Giardia. Metronidazole is the most commonly used drug to treat giardiasis. However, metronidazole resistance is increasingly common, making the development of new anti-giardial drugs a high priority. A panel of 11 compounds previously identified in T. ferdinandiana fruit extracts were investigated for the ability to inhibit G. duodenalis proliferation. Eight of the 11 compounds inhibited the growth of all three G. duodenalis strains. 2,3-Dihydroxyphenyl B-D-glucopyranosiduronic acid (DPGA) was the most potent anti-giardial compound, with IC50 values as low as 126 µM (38 µg/mL). Notably, DPGA inhibited a metronidazole-resistant G. duodenalis strain with similar activity as determined for the metronidazole-sensitive strains. Furthermore, the activity of DPGA was greatly potentiated when it was tested in combination with ascorbic acid, to approximately 17 µM (5 µg/mL) for the metronidazole-sensitive G. duodenalis strains and 40 µM (12 mg/mL) for the resistant strain. The T. ferdinandiana tannins (gallic acid and chebulic acid) were moderate inhibitors of G. duodenalis growth when tested in combination with ascorbic acid, although they had only low levels of activity when tested alone. All of the tested compounds (and their combinations with ascorbic acid) displayed low toxic effects and all compounds are conformed to Lipinski's rules of 5 with few violations, indicating their potential as drug leads and chemotherapies for the treatment and prevention of giardiasis.

Strategies of targeting pathological stroma for enhanced antitumor therapies.

Cancer associated fibroblasts (CAFs) and the derived stromal components constitute specific pathological stroma in desmoplastic tumors, which not only hinder the distribution of drugs/nano-agents in tumors but also reduce the sensibility of tumor cells to standard therapeutics. Consequently, pathological stroma has gradually been termed potential target for antitumor therapy. However, opposite outcomes have been observed to occur with the same strategy in different tumor models and no general principles have been adopted due to the heterogeneity and adaptivity of dynamic stroma, in which case diversified strategies for antitumor therapies are urgent. In this review, we summarize the origins and characterizations of pathological stroma and describe their critical influence on tumor's responsiveness to oncotherapy. The design of combinational antitumor strategies and stroma targeting drug delivery systems (DDSs) are also discussed in detail. Collectively, the main purpose of this review is to improve our understanding of the roles of stroma in tumor progression and provide new insights for targeting pathological stroma.

Terminalia chebula Retz. Fruit Extracts Inhibit Bacterial Triggers of Some Autoimmune Diseases and Potentiate the Activity of Tetracycline.

Terminalia chebula Retz. is a northern Indian plant species known for its anti-inflammatory and antimicrobial properties. T. chebula fruit powder was extracted with solvents of varying polarity and screened for bacterial growth inhibition by disc diffusion assay. The minimum inhibitory concentration (MIC) was quantified by both liquid dilution and disc diffusion techniques. To screen for combinatorial effects, the T. chebula fruit extracts were combined with a range of conventional antibiotics and tested against each bacteria using a liquid dilution assay. Where synergy was detected, the optimal ratios were determined using isobologram analysis. Toxicity was examined using Artemia nauplii and HDF bioassays. T. chebula fruit methanolic, aqueous and ethyl acetate extracts displayed strong antimicrobial activity against the bacterial triggers of all autoimmune inflammatory diseases except K. pneumoniae, for which only moderate inhibition was observed. Indeed, MIC values as low as 195 µg/mL were measured for the aqueous extract against a resistant strain of P. aeruginosa. Of further note, both the aqueous and ethyl acetate extracts interacted synergistically in combination with tetracycline against K. pneumoniae (Σ FIC 0.38 and 0.25 respectively). All extracts were nontoxic in the Artemia and HDF toxicity assays, further indicating their potential for medicinal use.

Targeting Glioma Initiating Cells with A combined therapy of cannabinoids and temozolomide.

Glioblastoma multiforme (GBM) is the most frequent and aggressive type of brain tumor due, at least in part, to its poor response to current anticancer treatments. These features could be explained, at least partially, by the presence within the tumor mass of a small population of cells termed Glioma Initiating Cells (GICs) that has been proposed to be responsible for the relapses occurring in this disease. Thus, the development of novel therapeutic approaches (and specifically those targeting the population of GICs) is urgently needed to improve the survival of the patients suffering this devastating disease. Previous observations by our group and others have shown that Δ9-Tetrahydrocannabinol (THC, the main active ingredient of marijuana) and other cannabinoids including cannabidiol (CBD) exert antitumoral actions in several animal models of cancer, including gliomas. We also found that the administration of THC (or of THC + CBD at a 1:1 ratio) in combination with temozolomide (TMZ), the benchmark agent for the treatment of GBM, synergistically reduces the growth of glioma xenografts. In this work we investigated the effect of the combination of TMZ and THC:CBD mixtures containing different ratios of the two cannabinoids in preclinical glioma models, including those derived from GICs. Our findings show that TMZ + THC:CBD combinations containing a higher proportion of CDB (but not TMZ + CBD alone) produce a similar antitumoral effect as the administration of TMZ together with THC and CBD at a 1:1 ratio in xenografts generated with glioma cell lines. In addition, we also found that the administration of TMZ + THC:CBD at a 1:1 ratio reduced the growth of orthotopic xenografts generated with GICs derived from GBM patients and enhanced the survival of the animals bearing these intracranial xenografts. Remarkably, the antitumoral effect observed in GICs-derived xenografts was stronger when TMZ was administered together with cannabinoid combinations containing a higher proportion of CBD. These findings support the notion that the administration of TMZ together with THC:CBD combinations - and specifically those containing a higher proportion of CBD - may be therapeutically explored to target the population of GICs in GBM.

Optimization of a preclinical therapy of cannabinoids in combination with temozolomide against glioma.

Glioblastoma multiforme (GBM) is the most frequent and aggressive form of brain cancer. These features are explained at least in part by the high resistance exhibited by these tumors to current anticancer therapies. Thus, the development of novel therapeutic approaches is urgently needed to improve the survival of the patients suffering this devastating disease. Δ9-Tetrahydrocannabinol (THC, the major active ingredient of marijuana), and other cannabinoids have been shown to exert antitumoral actions in animal models of cancer, including glioma. The mechanism of these anticancer actions relies, at least in part, on the ability of these compounds to stimulate autophagy-mediated apoptosis in tumor cells. Previous observations from our group demonstrated that local administration of THC (or of THC + CBD at a 1:1 ratio, a mixture that resembles the composition of the cannabinoid-based medicine Sativex®) in combination with Temozolomide, the benchmark agent for the treatment of GBM, synergistically reduces the growth of glioma xenografts. With the aim of optimizing the possible clinical utilization of cannabinoids in anti-GBM therapies, in this work we explored the anticancer efficacy of the systemic administration of cannabinoids in combination with TMZ in preclinical models of glioma. Our results show that oral administration of Sativex-like extracts (containing THC and CBD at a 1:1 ratio) in combination with TMZ produces a strong antitumoral effect in both subcutaneous and intracranial glioma cell-derived tumor xenografts. In contrast, combined administration of Sativex-like and BCNU (another alkylating agent used for the treatment of GBM which share structural similarities with the TMZ) did not show a stronger effect than individual treatments. Altogether, our findings support the notion that the combined administration of TMZ and oral cannabinoids could be therapeutically exploited for the management of GBM.

History of Glial Cell Line-Derived Neurotrophic Factor (GDNF) and Its Use for Spinal Cord Injury Repair.

Following an initial mechanical insult, traumatic spinal cord injury (SCI) induces a secondary wave of injury, resulting in a toxic lesion environment inhibitory to axonal regeneration. This review focuses on the glial cell line-derived neurotrophic factor (GDNF) and its application, in combination with other factors and cell transplantations, for repairing the injured spinal cord. As studies of recent decades strongly suggest that combinational treatment approaches hold the greatest therapeutic potential for the central nervous system (CNS) trauma, future directions of combinational therapies will also be discussed.

Is the pharmaceutical industry's preoccupation with the monotherapy drug model stifling the development of effective new drug therapies?

Drug discovery and development is heavily biased towards the development of monotherapies. Screening, testing, and evaluation of mono-entity drugs are generally much simpler than drug combinations, and are generally easier to get approval from the regulatory authorities for their clinical use. However, monotherapy drugs may not have optimal activity, may have associated toxicities, or may lose activity over time as their target develops resistance. Drug combinations, often developed from existing monotherapies, may have improved efficacy and/or be less toxic. Furthermore, the existing drugs which have lost efficacy due to the development of resistance can often be re-activated by combining them with other chemical entities. Thus, whilst the current climate for drug approval, registration, and clinical use drives the majority of drug development research towards the development of monotherapies, combinations are often a substantial improvement on the original drug. This commentary examines monotherapy and combinational therapy models and discusses the benefits and limitations of each model.