The multidrug resistance protein 4 is expressed and functionally active in isolated bladder from pig.

Multidrug resistance proteins type 4 (MRP4) and 5 (MRP5) play pivotal roles in the transport of cyclic nucleotides in various tissues. However, their specific functions within the lower urinary tract remain relatively unexplored. This study aimed to investigate the effect of pharmacological inhibition of MRPs on cyclic nucleotide signaling in isolated pig bladder. The relaxation responses of the bladder were assessed in the presence of the MRP inhibitor, MK571. The temporal changes in intra- and extracellular levels of cAMP and cGMP in stimulated tissues were determined by mass spectrometry. The gene (ABCC4) and protein (MRP4) expression were also determined. MK571 administration resulted in a modest relaxation effect of approximately 26% in carbachol-precontracted bladders. The relaxation induced by phosphodiesterase inhibitors such as cilostazol, tadalafil, and sildenafil was significantly potentiated in the presence of MK571. In contrast, no significant potentiation was observed in the relaxation induced by substances elevating cAMP levels or stimulators of soluble guanylate cyclase. Following forskolin stimulation, both intracellular and extracellular cAMP concentrations increased by approximately 15.8-fold and 12-fold, respectively. Similarly, stimulation with tadalafil + BAY 41-2272 resulted in roughly 8.2-fold and 3.4-fold increases in intracellular and extracellular cGMP concentrations, respectively. The presence of MK571 reduced only the extracellular levels of cGMP. This study reveals the presence and function of MRP4 transporters within the porcine bladder and paves the way for future research exploring the role of this transporter in both underactive and overactive bladder disorders.NEW & NOTEWORTHY This study investigates the impact of pharmacological inhibition of MRP4 and MRP5 transporters on cyclic nucleotide signaling in isolated pig bladders. MK571 administration led to modest relaxation, with enhanced effects observed in the presence of phosphodiesterase inhibitors. However, substances elevating cAMP levels remained unaffected. MK571 selectively reduced extracellular cGMP levels. These findings shed light on the role of MRP4 transporters in the porcine bladder, opening avenues for further research into bladder disorders.

Neoadjuvant Treatment of Locally Advanced Thyroid Cancer: A Preliminary Latin American Experience.

Background: Surgical resection is not always achievable in thyroid cancer patients. Neoadjuvant therapy is rarely used, but recent trends favor multikinase inhibitors or selective tyrosine kinase inhibitors. These aim to reduce tumor volume, enabling previously unfeasible surgeries. Patients and Methods: Consecutive patients with locally advanced malignant thyroid tumors who received systemic therapies with a neoadjuvant intention were included in this retrospective multicenter case series conducted in five Latin American referral centers. Primary outcomes were pre- versus postneoadjuvant response evaluations using the Response Evaluation Criteria in Solid Tumors, feasibility of surgery, and completeness of resection. Secondary outcomes were mortality and status at the last visit. Results: Twenty-seven patients were included in this analysis. Patients with unresectable differentiated thyroid cancer (DTC) or poorly differentiated thyroid cancer (PDTC) received sorafenib (n = 6) or lenvatinib (n = 12), those with medullary thyroid cancer (MTC) were treated with vandetanib (n = 5) or selpercatinib (n = 1), and those with anaplastic thyroid cancer (ATC) harboring a BRAFV600E mutation (n = 3) received dabrafenib and trametinib. The median patient age was 66 years (range 12-82), and 52% of the patients were female. In patients with PTC and PDTC, the median reduction in the diameter of the primary tumor was 25% (range 0-100%) after a median of 6 months of treatment. Surgical intervention was performed in 10 (55%) of the patients. Among these, six patients (60%) achieved R0/R1 resection status. Six patients with MTC had a median reduction in tumor diameter of 24.5% (range 1-49) after a median treatment time of 9.5 months. Only one patient receiving selpercatinib, with a tumoral reduction of 25% could undergo surgery, resulting in an R2 resection due to extensive mediastinal extension. Three patients with ATC showed a median tumor diameter reduction of 42% (range 6.7-50) after a median treatment time of 2 months. Two patients underwent surgical intervention and achieved R1 and R2 resection, respectively. Conclusions: While neoadjuvant therapy achieved tumoral responses, surgical resection was feasible in 55% of DTC, 33% of ATC, and 16% of MTC patients, with R0/R1 resection in 26% of the cohort, underscoring the need for patient selection and further research in this area.

Ten years' real-life experience on the use of multikinase inhibitors in patients with advanced differentiated thyroid cancer.

PURPOSE: To evaluate objective response rates (ORR), progression-free survival (PFS), and overall survival (OS) associated with tyrosine kinase inhibitors (TKIs) in patients with radioiodine refractory differentiated thyroid cancer (RR-DTC). Additionally, to compare: (i) ORR and PFS among patients treated with lenvatinib and sorafenib; (ii) ORR and PFS among patients receiving lenvatinib as first-line vs. second-line and; (iii) adverse effects (AEs) observed in patients treated with these medications. METHODS: Retrospective analysis of RR-DTC adult patients treated with TKIs at the Division of Endocrinology, Hospital de Clinicas, University of Buenos Aires (March 2011-November 2023). RESULTS: Among 43 patients included in the study, 32 received sorafenib (30 as first-line and 2 as second-line), while 29 received lenvatinib (12 as first-line and 17 as second-line). The median PFS and OS for the entire cohort were 32.7 and 39.0 months, respectively. Lenvatinib demonstrated a significantly higher ORR compared to sorafenib (37.9% vs. 9.4%, p = 0.008). However, both drugs exhibited similar median PFS (23.2 vs. 16.0 months, p = 0.419). No significant difference was observed in ORR and PFS between patients receiving first-line vs. second-line lenvatinib. Sorafenib-treated patients experienced higher rates of hand-foot skin syndrome (69% vs. 41%, p = 0.032) and alopecia (25% vs. 3%, p = 0.018), whereas lenvatinib-treated patients had higher rates of proteinuria (31% vs. 0%, p < 0.001) and grade 3 hypertension (31% vs. 9%, p = 0.034). CONCLUSION: TKIs demonstrated efficacy and tolerability comparable to real-world data in RR-DTC. PFS was not statistically different between sorafenib and lenvatinib. Our study will help guide physicians in making informed decisions regarding treatment sequencing with TKIs in these patients.

The hepatoprotective effect of 4-phenyltetrahydroquinolines on carbon tetrachloride induced hepatotoxicity in rats through autophagy inhibition.

BACKGROUND: The liver serves as a metabolic hub within the human body, playing a crucial role in various essential functions, such as detoxification, nutrient metabolism, and hormone regulation. Therefore, protecting the liver against endogenous and exogenous insults has become a primary focus in medical research. Consequently, the potential hepatoprotective properties of multiple 4-phenyltetrahydroquinolines inspired us to thoroughly study the influence of four specially designed and synthesized derivatives on carbon tetrachloride (CCl4)-induced liver injury in rats. METHODS AND RESULTS: Seventy-seven Wistar albino male rats weighing 140 ± 18 g were divided into eleven groups to investigate both the toxicity profile and the hepatoprotective potential of 4-phenyltetrahydroquinolines. An in-vivo hepatotoxicity model was conducted using CCl4 (1 ml/kg body weight, a 1:1 v/v mixture with corn oil, i.p.) every 72 h for 14 days. The concurrent treatment of rats with our newly synthesized compounds (each at a dose of 25 mg/kg body weight, suspended in 0.5% CMC, p.o.) every 24 h effectively lowered transaminases, preserved liver tissue integrity, and mitigated oxidative stress and inflammation. Moreover, the histopathological examination of liver tissues revealed a significant reduction in liver fibrosis, which was further supported by the immunohistochemical analysis of α-SMA. Additionally, the expression of the apoptotic genes BAX and BCL2 was monitored using real-time PCR, which showed a significant decrease in liver apoptosis. Further investigations unveiled the ability of the compounds to significantly decrease the expression of autophagy-related proteins, Beclin-1 and LC3B, consequently inhibiting autophagy. Finally, our computer-assisted simulation dockingonfirmed the obtained experimental activities. CONCLUSION: Our findings suggest that derivatives of 4-phenyltetrahydroquinoline demonstrate hepatoprotective properties in CCl4-induced liver damage and fibrosis in rats. The potential mechanism of action may be due to the inhibition of autophagy in liver cells.

Clinical efficacy of lenvatinib, trans-arterial chemoembolization, and PD-1/L1 inhibitors in advanced hepatocellular carcinoma: a systematic review and network meta-analysis.

BACKGROUND: Currently, the effectiveness of TACE, Lenvatinib, and PD-1/L1 inhibitors used alone or in combination has been thoroughly reported. However, the differences in effectiveness between these treatment protocols require further verification. To this end, this study employs a Bayesian network meta-analysis to compare the efficacy and safety of TACE, Lenvatinib, and PD-1/L1 inhibitors, whether administered by monotherapy or in combination, providing evidence-based medicine for the treatment of unresectable HCC. PURPOSE: This study employed a network meta-analysis to evaluate the efficacy and safety of trans-arterial chemoembolization (TACE), Programmed Cell Death Protein/Ligand 1 (PD-1/L1) inhibitors, and Lenvatinib in the treatment of advanced HCC. METHODS: Literature on the treatment of advanced HCC with TACE, PD-1/L1 inhibitors, and Lenvatinib was searched for in both Chinese and English databases, including PubMed, EMBASE, ClinicalTrials.gov, Cochrane Library, CNKI, and Wanfang. Two researchers conducted independent screening and data extraction, and the meta-analysis was performed using R language with the gemtc package. RESULTS: After retrieval and screening, a total of 21 articles were included, involving 2052 participants and six treatment modalities: Lenvatinib (L), TACE (T), TACE + Lenvatinib (TL), Lenvatinib + PD-1/L1 inhibitors (LP), TACE + Lenvatinib + PD-1/L1 inhibitors (TLP), and TACE + PD-1/L1 inhibitors (TP). In terms of objective response rate (ORR), the TLP regimen provided the optimal effect. In predicting the best ORR, TLP had the highest (75.5%) probability. In terms of disease control rate (DCR), the TLP regimen showed the best effect. In predicting the best DCR, the TLP again offered the highest (76.1%) probability. In terms of overall survival (OS), the best outcome was observed in the TLP protocol. In predicting the best OS, the TLP holds the highest (86.00%) probability. Furthermore, the best outcome in progression-free survival (PFS) was found in the TLP regimen. In predicting the best PFS, the TLP still holds the highest (97.0%) result. CONCLUSION: The combination of TACE, Lenvatinib, and PD-1/L1 inhibitors appears to provide the maximum benefit for inoperable HCC patients.

Biochar obtained from eucalyptus, rice hull, and native bamboo as an alternative to decrease mobility of hexazinone, metribuzin, and quinclorac in a tropical soil.

Mobile herbicides have a high potential for groundwater contamination. An alternative to decrease the mobility of herbicides is to apply materials with high sorbent capacity to the soil, such as biochars. The objective of this research was to evaluate the effect of eucalyptus, rice hull, and native bamboo biochar amendments on sorption and desorption of hexazinone, metribuzin, and quinclorac in a tropical soil. The sorption-desorption was evaluated using the batch equilibrium method at five concentrations of hexazinone, metribuzin, and quinclorac. Soil was amended with eucalyptus, rice hull, and native bamboo biochar at a rate of 0 (control-unamended) and 1% (w w-1), corresponding to 0 and 12 t ha-1, respectively. The amount of sorbed herbicides in the unamended soil followed the decreasing order: quinclorac (65.9%) > metribuzin (21.4%) > hexazinone (16.0%). Native bamboo biochar provided the highest sorption compared to rice hull and eucalyptus biochar-amended soils for the three herbicides. The amount of desorbed herbicides in the unamended soil followed the decreasing order: metribuzin (18.35%) > hexazinone (15.9%) > quinclorac (15.1%). Addition of native bamboo biochar provided the lowest desorption among the biochar amendments for the three herbicides. In conclusion, the biochars differently affect the sorption and desorption of hexazinone, metribuzin, and quinclorac mobile herbicides in a tropical soil. The addition of eucalyptus, rice hull, and native bamboo biochars is a good alternative to increase the sorption of hexazinone, metribuzin, and quinclorac, thus, reducing mobility and availability of these herbicides to nontarget organisms in soil.

Efficacy and safety of anlotinib plus anti-PD-1 agents in patients with refractory advanced biliary tract cancers.

BACKGROUND: Anlotinib has demonstrated promising anti-tumor efficacy in various solid tumors. Additionally, there is evidence suggesting that immune therapy can enhance the systemic responses of anlotinib. This study aimed to assess the effectiveness and safety of combining anlotinib with PD-1 inhibitors compared to fluoropyrimidine-based chemotherapy as a second-line treatment option for advanced biliary tract cancers (BTCs). METHODS: A total of 242 patients with BTCs were screened at the First Affiliated Hospital of Zhengzhou University from October 2015 to October 2022. Among them, 78 patients who received either anlotinib plus PD-1 inhibitors (AP) or fluoropyrimidine-based chemotherapy (FB) as second-line treatment were included in the study. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included objective response rate (ORR), disease control rate (DCR), overall survival (OS), safety, and predictive tumor biomarkers. RESULTS: Among the 78 patients with BTCs, 39 patients received AP, while 39 patients were administered FB. The ORR in the AP group was 20.5%, compared to 5.1% in the FB group. The DCR was 87.2% in the AP group and 66.7% in the FB group. The AP group demonstrated significantly better ORR and DCR compared to the FB group (p = 0.042, p = 0.032). The median PFS and OS in the AP group were 7.9 months (95% CI: 4.35-11.45) and 13.9 months (95% CI: 5.39-22.41), respectively. In the FB group, the median PFS and OS were 4.1 months (95% CI: 3.17-5.03) and 13.2 months (95% CI: 8.72-17.68), respectively. The AP group exhibited significantly better median PFS than the FB group (p = 0.027). In the subgroup analysis, patients without liver metastasis had a much longer PFS in the AP group compared to the FB group (14.3 vs. 5.5 months, p = 0.016). Similarly, patients with CEA ≤ 5 µg/L also demonstrated a longer PFS in the AP group compared to the FB group (8.7 vs. 3.9 months, p = 0.008). CONCLUSIONS: The combination of anlotinib and PD-1 inhibitors demonstrated a promising clinical effect compared to fluoropyrimidine-based chemotherapy in the second-line treatment of refractory advanced BTCs. Liver metastases and CEA levels may serve as predictive factors for identifying patients who may benefit from AP therapy.

Comparison of treatment efficacy of omega-3 fish oil and montelukast in ovalbumin-protease-induced allergic rhinitis model in rats.

OBJECTIVES: Montelukast is a well-known leukotriene receptor antagonist commonly used in treating allergic rhinitis and asthma. Omega-3 fatty acid is also known as an antiallergic and immunomodulator molecule. This study aimed to elucidate the efficacy of systemic montelukast and omega-3 fatty acid treatment in allergic rhinitis models in Wistar Hannover rats. METHODS: This research was conducted on 28 healthy Wistar Hannover rats weighing 250-350 g. After establishing the allergic rhinitis model, nasal symptoms were observed and scored, and the nasal mucosa of all rats was investigated histologically. Light microscopy was utilized to evaluate the degree of ciliary loss, goblet cell hyperplasia, vascular congestion, vascular proliferation, inflammatory cell infiltration, eosinophil infiltration, and hypertrophy in chondrocytes. RESULTS: As a result of the analysis of the data obtained from the study, it was determined that typical allergic rhinitis symptoms such as nasal scratching and sneezing were significantly reduced in the rats in the montelukast and omega-3 treated group, and these symptoms did not increase after repeated intranasal OVA-protease applications. Histological examinations after fish oil treatment did not reveal typical inflammatory changes in allergic rhinitis. None of the rats in the montelukast and omega-3 groups had any increase in goblet cells, whereas 14.3% of the rats in the control group and 28.6% of the rats in the allergic rhinitis group had mild increase. Last but not least, 71.4% of rats in the allergic rhinitis group had a moderate increase. The difference between the groups was statistically significant (p < 0.001). CONCLUSION: Regarding the outcomes of this research, it was observed that w-3 fatty acids had antiallergic effects, both histopathological and clinical, in the allergic rhinitis model. We believe that further randomized controlled trials incorporating larger cohorts are warranted to verify the use of omega-3 fatty acids in treating allergic rhinitis. The level of evidence of this article is Level 2.

Synthesis and In vitro and In silico Anti-inflammatory Activity of New Thiazolidinedione-quinoline Derivatives.

BACKGROUND: Inflammation is a series of complex defense-related reactions. The inflammation cascade produces various pro-inflammatory mediators. Unregulated production of these pro-inflammatory mediators can lead to a wide range of diseases, including rheumatoid arthritis, sepsis, and inflammatory bowel disease. In the literature, the anti-inflammatory action of quinoline and thiazolidinedione nuclei are well established, alone, and associated with other nuclei. The synthesis of hybrid molecules is a strategy for obtaining more efficient molecules due to the union of pharmacophoric nuclei known to be related to pharmacological activity. OBJECTIVES: Based on this, this work presents the synthesis of thiazolidinedione-quinoline molecular hybrids and their involvement in the modulation of cytokines involved in the inflammatory reaction cascade. METHODS: After synthesis and characterization, the compounds were submitted to cell viability test (MTT), ELISA IFN-γ and TNF-α, adipogenic differentiation, and molecular docking assay with PPARy and COX-2 targets. RESULTS: LPSF/ZKD2 and LPSF/ZKD7 showed a significant decrease in the concentration of IFN- γ and TNF-α, with a dose-dependent behavior. LPSF/ZKD4 at a concentration of 50 µM significantly reduced IL-6 expression. LPSF/ZKD4 demonstrates lipid accumulation with significant differences between the untreated and negative control groups, indicating a relevant agonist action on the PPARγ receptor. Molecular docking showed that all synthesized compounds have good affinity with PPARγ e COX-2, with binding energy close to -10,000 Kcal/mol. CONCLUSION: These results demonstrate that the synthesis of quinoline-thiazolidinedione hybrids may be a useful strategy for obtaining promising candidates for new anti-inflammatory agents.

Anlotinib suppressed tumor cell proliferation and migration in hypopharyngeal carcinoma.

OBJECTIVE: The purpose of this study is to study the in-vitro effects of multitarget inhibitor anlotinib on hypopharyngeal cancer cell proliferation and cell migration, and the underlying mechanism, which will provide new drug choices for hypopharyngeal cancer treatment. METHODS: The Hypopharyngeal cancer Fadu cells were treated with anlotinib at a concentration of 0, 5, and 10 µmoL/L, respectively. Cell counting kit-8 and the colony-forming assay were used to detect the inhibition of cell proliferation. Wound-healing assay and transwell assay were used to detect the migration and invasion ability of cells. Flow cytometry was used to detect the effects of anlotinib on cell cycle and apoptosis. RT-qPCR and Western blot were used to measure gene expression levels. RESULTS: CCK-8 and colony-forming assay showed that anlotinib could significantly inhibit cell proliferative activity. Wound-healing assay and transwell assay showed that anlotinib could inhibit cell migration and scratch. These results showed that anlotinib has obvious antitumor activity. Flow cell cycle experiment showed that anlotinib could promote Fadu cell apoptosis and block the G2/M phase for inhibiting cell proliferation. In addition, anlotinib decreased the expression of HIF-1α. CONCLUSIONS: Anlotinib has an excellent suppressing effect on the proliferation, migration, and invasion of hypopharyngeal cancer Fadu cells in-vitro. Moreover, it can play an anti-tumor role through blocking cell cycle G2/M and promoting apoptosis, which may be related to the decrease of HIF-1a expression. Our study would provide a potential treatment method for patients with hypopharyngeal cancer. LEVEL OF EVIDENCE: Level 3.

Comparison of the efficacy and safety of anlotinib monotherapy or anlotinib plus immune checkpoint inhibitor for advanced small cell lung cancer with brain metastases.

BACKGROUND: Anlotinib, as a salvage treatment for patients after failure of third-line or later-line treatments for small cell lung cancer (SCLC), has shown efficacy in patients with brain metastases (BMs). However, the efficacy and safety of anlotinib alone or in combination with immunotherapy for SCLC with BMs remain unclear. METHOD: Patients treated with anlotinib alone or in combination with an immune checkpoint inhibitor (ICI) at the Zhejiang Cancer Hospital between April 2019 and February 2023 were identified. Kaplan-Meier curves were used to describe the progression-free survival (PFS) and intracranial PFS (iPFS). A waterfall diagram was used to indicate changes in intracranial lesions. RESULTS: A total of 48 patients were included; 29 received anlotinib alone, and 19 were administered anlotinib plus ICI. Combination therapy, compared with anlotinib, was associated with significantly longer PFS and iPFS (PFS: 8.1 months vs. 2.5 months, P < 0.001; iPFS: 8.1 months vs. 2.5 months, P = 0.004). Similar results were observed in patients with multiple BMs (PFS: 8.1 months vs. 1.9 months, P = 0.001; iPFS: 8.1 months vs. 1.9 months, P = 0.002). After third-line or later-line treatments, patients treated with ICI plus anlotinib also achieved significant PFS and iPFS benefits (PFS: 8.4 months vs. 2.1 months, P < 0.001; iPFS: 9.2 months vs. 2.1 months, P = 0.002). No new or severe adverse events were observed with combination therapy. CONCLUSION: The combination of anlotinib and ICI has promising intracranial and extracranial efficacy with tolerable toxicity, and may be a therapeutic option for SCLC patients with BMs.

Inhibition of anlotinib-induced autophagy attenuates invasion and migration by regulating epithelial-mesenchymal transition and cytoskeletal rearrangement through ATG5 in human osteosarcoma cells.

The cure rates for osteosarcoma have remained unchanged in the past three decades, especially for patients with pulmonary metastasis. Thus, a new and effective treatment for metastatic osteosarcoma is urgently needed. Anlotinib has been reported to have antitumor effects on advanced osteosarcoma. However, both the effect of anlotinib on autophagy in osteosarcoma and the mechanism of anlotinib-mediated autophagy in pulmonary metastasis are unclear. The effect of anlotinib treatment on the metastasis of osteosarcoma was investigated by transwell assays, wound healing assays, and animal experiments. Related proteins were detected by western blotting after anlotinib treatment, ATG5 silencing, or ATG5 overexpression. Immunofluorescence staining and transmission electron microscopy were used to detect alterations in autophagy and the cytoskeleton. Anlotinib inhibited the migration and invasion of osteosarcoma cells but promoted autophagy and increased ATG5 expression. Furthermore, the decreases in invasion and migration induced by anlotinib treatment were enhanced by ATG5 silencing. In addition, Y-27632 inhibited cytoskeletal rearrangement, which was rescued by ATG5 overexpression. ATG5 overexpression enhanced epithelial-mesenchymal transition (EMT). Mechanistically, anlotinib-induced autophagy promoted migration and invasion by activating EMT and cytoskeletal rearrangement through ATG5 both in vitro and in vivo. Our results demonstrated that anlotinib can induce protective autophagy in osteosarcoma cells and that inhibition of anlotinib-induced autophagy enhanced the inhibitory effects of anlotinib on osteosarcoma metastasis. Thus, the therapeutic effect of anlotinib treatment can be improved by combination treatment with autophagy inhibitors, which provides a new direction for the treatment of metastatic osteosarcoma.

Quinoline-2-one derivatives as promising antibacterial agents against multidrug-resistant Gram-positive bacterial strains.

This study describes the discovery of a variety of quinoline2-one derivatives with significant antibacterial action vs a spectrum of multidrug-resistant Gram-positive bacterial strains, especially methicillin-resistant Staphylococcus aureus (MRSA). Compounds 6c, 6l, and 6o exhibited significant antibacterial activity versus the Gram-positive bacterial pathogens evaluated. In comparison to the reference daptomycin, compound 6c demonstrated the most effective activity among the assessed derivatives, with MIC concentrations of 0.75 µg/mL versus MRSA and VRE and 2.50 µg/mL against MRSE. We also reported on these compounds' biofilm and dihydrofolate reductase inhibitory activities. Compound 6c showed the greatest antibiofilm action in a dose-dependent way and a substantial decrease of biofilm development in the MRSA ACL51 strain at concentrations of 0.5, 0.25, and 0.12 MIC, with reductions of 79%, 55%, and 38%, consecutively, whereas the corresponding values for vancomycin were 20%, 12%, and 9%. These findings imply that these quinoline compounds could be used to develop a new category of antibiotic representatives to prevent Gram-positive drug-resistant bacterial strains.

Antimalarial Agents Derived from Metal-Amodiaquine Complexes with Activity in Multiple Stages of the Plasmodium Life Cycle.

Malaria is the one of the deadliest infectious diseases worldwide. Chemically, quinolines are excellent ligands for metal coordination and are deployed as drugs for malaria treatment. There is a growing body of evidence indicating that metal complexes can be conjugated with antimalarial quinolines to be used as chemical tools to overcome the disadvantages of quinolines, improving their bioactive speciation, cellular distribution, and subsequently broadening the spectrum of activity to multiple stages of the complex Plasmodium life cycle. In this study, four novel complexes of ruthenium(II)- and gold(I)-containing amodiaquine (AQ) were synthesized, and a careful chemical characterization revealed the precise coordination site of AQ to the metals. Their speciation in solution was investigated, demonstrating the stability of the quinoline-metal bond. RuII - and AuI -AQ complexes were demonstrated to be potent and efficacious in inhibiting parasite growth in multiple stages of the Plasmodium life cycle as assayed in vitro and in vivo. These properties could be attributed to the ability of the metal-AQ complexes to reproduce the suppression of heme detoxification induced by AQ, while also inhibiting other processes in the parasite life cycle; this can be attributed to the action of the metallic species. Altogether, these findings indicate that metal coordination with antimalarial quinolines is a potential chemical tool for drug design and discovery in malaria and other infectious diseases susceptible to quinoline treatment.

Bioinspired nanoarchitectonics at the air-water interface to understand the interaction of lipids with a Europium-coordinated quinoline derivative.

5SO3H-8-hydroxyquinoline coordinated to Europium (Eu-5SO3-HQ) was incorporated in biomembrane models using Langmuir monolayers. Dipalmitoyl phosphatidylcholine (DPPC) and dipalmitoyl phosphatidylserine (DPPS) were employed, representing mammalian cells and dioctadecyldimethylammonium bromide (DODAB) as a positively charged lipid to study the contrast with negatively charged lipids. Tensiometric, rheological and spectroscopic techniques were employed to characterize Eu-5SO3-HQ- lipid monolayer interactions. The complex condenses all the monolayer indicating interactions with the lipids' polar heads, but with distinctive effects on the mechanical and rheological properties. While the complex decreases the compression and elastic moduli of DPPC and DPPS monolayers, it increases for DODAB, also decreasing its lateral viscosity. Infrared spectroscopy shows that the interaction of Eu-5-SO3-HQ alters the ordering of the lipids' alkyl chains, impacting the monolayer's molecular packing. These results show that the interaction of Eu-5SO3-HQ with lipid monolayers at the air-water is modulated by the composition of the polar head, which can be supportive in the preparation of nanodevices for molecular probing.

Synthesis of 4-(Phenylchalcogenyl)tetrazolo[1,5-a]quinolines by Bicyclization of 2-Azidobenzaldehydes with Phenylchalcogenylacetonitrile.

A general methodology to access valuable 4-(phenylchalcogenyl)tetrazolo[1,5-a]quinolines was developed by the reaction of 2-azidobenzaldehyde with phenylchalcogenylacetonitriles (sulfur and selenium) in the presence of potassium carbonate (20 mol%) as a catalyst. The reactions were conducted using a mixture of dimethylsulfoxide and water (7:3) as solvent at 80 °C for 4 h. This new methodology presents a good functional group tolerance to electron-deficient and electron-rich substituents, affording a total of twelve different 4-(phenylchalcogenyl)tetrazolo[1,5-a]quinolines selectively in moderate to excellent yields. The structure of the synthesized 4-(phenylselanyl)tetrazolo[1,5-a]quinoline was confirmed by X-ray analysis.