Multifaceted Mechanisms Of Action Research Articles

Rifaximin: A Comprehensive Review of Structure, Uses, Mechanisms of Action, and Assay Methods

Rifaximin, a derivative of rifamycin, has emerged as a promising therapeutic tool in gastroenterology. This review explores rifaximin's intricate molecular structure and pharmacokinetic properties, highlighting its minimal systemic absorption and targeted action within the gut. The multifaceted mechanisms of action, including direct antibacterial effects and modulation of gut microbiota, are discussed. The review then examines the efficacy of rifaximin in treating various gastrointestinal disorders like traveler's diarrhea, Irritable Bowel Syndrome with Diarrhea (IBS-D), and Small Intestinal Bacterial Overgrowth (SIBO). Dosage recommendations and the well-tolerated safety profile of rifaximin are presented. Finally, the importance of quality control measures using techniques like HPLC and spectroscopy is emphasized to ensure the drug's effectiveness and safety.

Epigallocatechin gallate modulates ferroptosis through downregulation of tsRNA-13502 in non-small cell lung cancer

Ferroptosis, an iron-dependent regulated cell death mechanism, holds significant promise as a therapeutic strategy in oncology. In the current study, we explored the regulatory effects of epigallocatechin gallate (EGCG), a prominent polyphenol in green tea, on ferroptosis and its potential therapeutic implications for non-small cell lung cancer (NSCLC). Treatment of NSCLC cell lines with varying concentrations of EGCG resulted in a notable suppression of cell proliferation, as evidenced by a reduction in Ki67 immunofluorescence staining. Western blot analyses demonstrated that EGCG treatment led to a decrease in the expression of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) while increasing the levels of acyl-CoA synthetase long-chain family member 4 (ACSL4). These molecular changes were accompanied by an increase in intracellular iron, malondialdehyde (MDA), and reactive oxygen species (ROS), alongside ultrastructural alterations characteristic of ferroptosis. Through small RNA sequencing and RT-qPCR, transfer RNA-derived small RNA 13502 (tsRNA-13502) was identified as a significant target of EGCG action, with its expression being upregulated in NSCLC tissues compared to adjacent non-tumorous tissues. EGCG was found to modulate the ferroptosis pathway by downregulating tsRNA-13502 and altering the expression of key ferroptosis regulators (GPX4/SLC7A11 and ACSL4), thereby promoting the accumulation of iron, MDA, and ROS, and ultimately inducing ferroptosis in NSCLC cells. This study elucidates EGCG’s multifaceted mechanisms of action, underscoring the modulation of ferroptosis as a viable therapeutic approach for enhancing NSCLC treatment outcomes.

Advancements and recent explorations of anti-cancer activity of chrysin: from molecular targets to therapeutic perspective.

In recent times, there have been notable advancements in comprehending the potential anti-cancer effects of chrysin (CH), a naturally occurring flavonoid compound found abundantly in various plant sources like honey, propolis, and certain fruits and vegetables. This active compound has garnered significant attention due to its promising therapeutic qualities and minimal toxicity. CH's ability to combat cancer arises from its multifaceted mechanisms of action, including the initiation of apoptosis and the inhibition of proliferation, angiogenesis, metastasis, and cell cycle progression. CH also displays potent antioxidant and anti-inflammatory properties, effectively counteracting the harmful molecules that contribute to DNA damage and the development of cancer. Furthermore, CH has exhibited the potential to sensitize cancer cells to traditional chemotherapy and radiotherapy, amplifying the effectiveness of these treatments while reducing their negative impact on healthy cells. Hence, in this current review, the composition, chemistry, mechanisms of action, safety concerns of CH, along with the feasibility of its nanoformulations. To conclude, the recent investigations into CH's anti-cancer effects present a compelling glimpse into the potential of this natural compound as a complementary therapeutic element in the array of anti-cancer approaches, providing a safer and more comprehensive method of combating this devastating ailment.

The multifaceted role of fluoride in preventing early childhood caries: A comprehensive review

Early childhood caries (ECC) remains a prevalent and significant public health concern worldwide, particularly in underserved communities. Fluoride has long been recognized as a cornerstone in ECC prevention due to its multifaceted mechanisms of action, including topical effects on enamel, systemic effects on dental development, antimicrobial properties, and the ability to promote remineralization of early carious lesions. This comprehensive review explores the various roles of fluoride in preventing ECC, encompassing its sources, efficacy, safety considerations, delivery strategies, challenges, and future directions. Community water fluoridation, fluoride toothpaste, mouth rinses, professional treatments, and dietary sources constitute primary means of fluoride exposure. Extensive clinical trials, epidemiological studies, meta-analyses, and systematic reviews provide robust evidence supporting the effectiveness of fluoride in reducing ECC prevalence and severity. However, optimizing fluoride exposure levels while minimizing the risk of dental fluorosis remains a critical consideration, especially in vulnerable populations. Strategies for fluoride delivery in high-risk groups, such as early childhood interventions, school-based programs, and community outreach initiatives, play pivotal roles in promoting oral health equity. Nevertheless, challenges persist, including limited access to fluoride in underserved areas, public misconceptions, and the need for further research on novel fluoride formulations. Fluoride continues to be a vital tool in ECC prevention, with implications for both clinical practice and public health policy. Addressing disparities in fluoride access and enhancing community engagement are essential for maximizing its impact in reducing ECC burden globally. Future research endeavors should focus on innovative approaches to fluoride delivery and long-term oral health outcomes in diverse populations.

Comparative Assessment of the Binding and Neutralisation Activity of Bispecific Antibodies Against SARS-CoV-2 Variants.

Neutralising antibodies against SARS-CoV-2 are a vital component in the fight against COVID-19 pandemic, having the potential of both therapeutic and prophylactic applications. Bispecific antibodies (BsAbs) against SARS-CoV-2 are particularly promising, given their ability to bind simultaneously to two distinct sites of the receptor-binding domain (RBD) of the viral spike protein. Such antibodies are complex molecules associated with multi-faceted mechanisms of action that require appropriate bioassays to ensure product quality and manufacturing consistency. We developed procedures for biolayer interferometry (BLI) and a cell-based virus neutralisation assay, the focus reduction neutralisation test (FRNT). Using both assays, we tested a panel of five BsAbs against different spike variants (Ancestral, Delta and Omicron) to evaluate the use of these analytical methods in assessing binding and neutralisation activities of anti-SARS-CoV-2 therapeutics. We found comparable trends between BLI-derived binding affinity and FRNT-based virus neutralisation activity. Antibodies that displayed high binding affinity against a variant were often followed by potent neutralisation at lower concentrations, whereas those with low binding affinity also demonstrated reduced neutralisation activity. The results support the utility of BLI and FRNT assays in measuring variant-specific binding and virus neutralisation activity of anti-SARS-CoV-2 antibodies.

Multitalented Synthetic Antimicrobial Peptides and Their Antibacterial, Antifungal and Antiviral Mechanisms.

Despite the great strides in healthcare during the last century, some challenges still remained unanswered. The development of multi-drug resistant bacteria, the alarming growth of fungal infections, the emerging/re-emerging of viral diseases are yet a worldwide threat. Since the discovery of natural antimicrobial peptides able to broadly hit several pathogens, peptide-based therapeutics have been under the lenses of the researchers. This review aims to focus on synthetic peptides and elucidate their multifaceted mechanisms of action as antiviral, antibacterial and antifungal agents. Antimicrobial peptides generally affect highly preserved structures, e.g., the phospholipid membrane via pore formation or other constitutive targets like peptidoglycans in Gram-negative and Gram-positive bacteria, and glucan in the fungal cell wall. Additionally, some peptides are particularly active on biofilm destabilizing the microbial communities. They can also act intracellularly, e.g., on protein biosynthesis or DNA replication. Their intracellular properties are extended upon viral infection since peptides can influence several steps along the virus life cycle starting from viral receptor-cell interaction to the budding. Besides their mode of action, improvements in manufacturing to increase their half-life and performances are also taken into consideration together with advantages and impairments in the clinical usage. Thus far, the progress of new synthetic peptide-based approaches is making them a promising tool to counteract emerging infections.

β-Hexachlorocyclohexane: A Small Molecule with a Big Impact on Human Cellular Biochemistry.

Organochlorine pesticides (OCPs) belong to a heterogeneous class of organic compounds blacklisted by the Stockholm Convention in 2009 due to their harmful impact on human health. Among OCPs, β-hexachlorocyclohexane (β-HCH) is one of the most widespread and, at the same time, poorly studied environmental contaminant. Due to its physicochemical properties, β-HCH is the most hazardous of all HCH isomers; therefore, clarifying the mechanisms underlying its molecular action could provide further elements to draw the biochemical profile of this OCP. For this purpose, LNCaP and HepG2 cell lines were used as models and were subjected to immunoblot, immunofluorescence, and RT-qPCR analysis to follow the expression and mRNA levels, together with the distribution, of key biomolecules involved in the intracellular responses to β-HCH. In parallel, variations in redox homeostasis and cellular bioenergetic profile were monitored to have a complete overview of β-HCH effects. Obtained results strongly support the hypothesis that β-HCH could be an endocrine disrupting chemical as well as an activator of AhR signaling, promoting the establishment of an oxidative stress condition and a cellular metabolic shift toward aerobic glycolysis. In this altered context, β-HCH can also induce DNA damage through H2AX phosphorylation, demonstrating its multifaceted mechanisms of action.

Antifungal symbiotic peptide NCR044 exhibits unique structure and multifaceted mechanisms of action that confer plant protection

In the indeterminate nodules of a model legume Medicago truncatula, ∼700 nodule-specific cysteine-rich (NCR) peptides with conserved cysteine signature are expressed. NCR peptides are highly diverse in sequence, and some of these cationic peptides exhibit antimicrobial activity in vitro and in vivo. However, there is a lack of knowledge regarding their structural architecture, antifungal activity, and modes of action against plant fungal pathogens. Here, the three-dimensional NMR structure of the 36-amino acid NCR044 peptide was solved. This unique structure was largely disordered and highly dynamic with one four-residue α-helix and one three-residue antiparallel β-sheet stabilized by two disulfide bonds. NCR044 peptide also exhibited potent fungicidal activity against multiple plant fungal pathogens, including Botrytis cinerea and three Fusarium spp. It inhibited germination in quiescent spores of B. cinerea In germlings, it breached the fungal plasma membrane and induced reactive oxygen species. It bound to multiple bioactive phosphoinositides in vitro. Time-lapse confocal and superresolution microscopy revealed strong fungal cell wall binding, penetration of the cell membrane at discrete foci, followed by gradual loss of turgor, subsequent accumulation in the cytoplasm, and elevated levels in nucleoli of germlings. Spray-applied NCR044 significantly reduced gray mold disease symptoms caused by the fungal pathogen B. cinerea in tomato and tobacco plants, and postharvest products. Our work illustrates the antifungal activity of a structurally unique NCR peptide against plant fungal pathogens and paves the way for future development of this class of peptides as a spray-on fungistat/fungicide.

High-Parameter Mass Cytometry (CyTOF) Evaluation of Relapsed/Refractory Multiple Myeloma (MM) Pts (Pts) Treated with Daratumumab Supports Immune Modulation As a Novel Mechanism of Action

High-Parameter Mass Cytometry (CyTOF) Evaluation of Relapsed/Refractory Multiple Myeloma (MM) Pts (Pts) Treated with Daratumumab Supports Immune Modulation As a Novel Mechanism of Action

Evaluation of Minimal Residual Disease (MRD) in Relapsed/Refractory Multiple Myeloma (RRMM) Patients Treated with Daratumumab in Combination with Lenalidomide Plus Dexamethasone or Bortezomib Plus Dexamethasone

Evaluation of Minimal Residual Disease (MRD) in Relapsed/Refractory Multiple Myeloma (RRMM) Patients Treated with Daratumumab in Combination with Lenalidomide Plus Dexamethasone or Bortezomib Plus Dexamethasone

The Therapeutic CD38 Monoclonal Antibody Daratumumab Induces Programmed Cell Death via Fcγ Receptor-Mediated Cross-Linking.

Emerging evidence suggests that FcγR-mediated cross-linking of tumor-bound mAbs may induce signaling in tumor cells that contributes to their therapeutic activity. In this study, we show that daratumumab (DARA), a therapeutic human CD38 mAb with a broad-spectrum killing activity, is able to induce programmed cell death (PCD) of CD38(+) multiple myeloma tumor cell lines when cross-linked in vitro by secondary Abs or via an FcγR. By comparing DARA efficacy in a syngeneic in vivo tumor model using FcRγ-chain knockout or NOTAM mice carrying a signaling-inactive FcRγ-chain, we found that the inhibitory FcγRIIb as well as activating FcγRs induce DARA cross-linking-mediated PCD. In conclusion, our in vitro and in vivo data show that FcγR-mediated cross-linking of DARA induces PCD of CD38-expressing multiple myeloma tumor cells, which potentially contributes to the depth of response observed in DARA-treated patients and the drug's multifaceted mechanisms of action.

Protective Effects of Anethole Dithiolethione against Oxidative Stress-induced Cytotoxicity in Human Jurkat T Cells

The protective effects of anethole dithiolethione (ADT) against H 2O 2- or 4-hydroxynonenal (HNE)-induced cytotoxicity in human Jurkat T cells were investigated. Jurkat T cells were pretreated with ADT (10–50 μM) for 18 hr and then challenged with H 2O 2 or HNE for up to 4 hr. Cytotoxicity was assessed by measuring: 1) leakage of lactate dehydrogenase from cells to medium; and 2) exclusion of the DNA intercalating fluorescent probe propidium iodide by viable cells. Pretreatment of cells with ADT (10 or 25 μM) for 18 hr significantly protected cells against H 2O 2- or HNE-induced cytotoxicity. Treatment of cells with ADT (10–50 μM) for 72 hr significantly increased the activities of catalase and glutathione reductase. The maximum effect of ADT treatment on the activity of these enzymes was observed when cells were treated with 25 μM of ADT for 72 hr. A significant increase in cellular GSH was observed in cells that were treated with ADT for 72 hr. Using monobromobimane as a thiol probe, we consistently observed that cells pretreated for 18 hr with ADT (25 or 50 μM) had also increased total thiol content. Exposure of Jurkat T cells to H 2O 2 or HNE resulted in a time-dependent decrease in cellular GSH. ADT (10–50 μM, 18 hr) pretreatment circumvented H 2O 2-dependent lowering of cellular GSH. In conclusion, ADT proved to be a potent cytoprotective thiol antioxidant with multifaceted mechanisms of action, suggesting that the drug has a remarkable therapeutic potential.