Molecular insights on Eltrombopag: potential mitogen stimulants, angiogenesis, and therapeutic radioprotectant through TPO-R activation.

The purpose of this study is to investigate the molecular interactions and potential therapeutic uses of Eltrombopag (EPAG), a small molecule that activates the cMPL receptor. EPAG has been found to be effective in increasing platelet levels and alleviating thrombocytopenia. We utilized computational techniques to predict and confirm the complex formed by the ligand (EPAG) and the Thrombopoietin receptor (TPO-R) cMPL, elucidating the role of RAS, JAK-2, STAT-3, and other essential elements for downstream signaling. Molecular dynamics (MD) simulations were employed to evaluate the stability of the ligand across specific proteins, showing favorable characteristics. For the first time, we examined the presence of TPO-R in human umbilical cord mesenchymal stem cells (hUCMSC) and human gingival mesenchymal stem cells (hGMSC) proliferation. Furthermore, treatment with EPAG demonstrated angiogenesis and vasculature formation of endothelial lineage derived from both MSCs. It also indicated the activation of critical factors such as RUNX-1, GFI-1b, VEGF-A, MYB, GOF-1, and FLI-1. Additional experiments confirmed that EPAG could be an ideal molecule for protecting against UVB radiation damage, as gene expression (JAK-2, ERK-2, MCL-1, NFkB, and STAT-3) and protein CD90/cMPL analysis showed TPO-R activation in both hUCMSC and hGMSC. Overall, EPAG exhibits significant potential in treating radiation damage and mitigating the side effects of radiotherapy, warranting further clinical exploration.

What is the context?● Chemotherapy, radiation treatment, or immunological disorders can cause a decrease in platelet count (thrombocytopenia) or decrease all blood cell types (pancytopenia) in the bone marrow. This can make it challenging to choose the appropriate cancer treatment plan.● Eltrombopag (EPAG) is an oral non-peptide thrombopoietin (TPO) mimetic that activates the cMPL receptor in the body. This activation leads to cell differentiation and proliferation, stimulating platelet production and reducing thrombocytopenia. The cMPL receptor is present in liver cells, megakaryocytes, and hematopoietic cells. However, its effects on stem cell proliferation and differentiation are not entirely understood.What is the new?● This study delves into the molecular interactions and therapeutic applications of EPAG, a small molecule that activates cMPL (TPO-R).● The study offers a comprehensive analysis of the ligand-receptor complex formation, including an examination of downstream signaling elements. Furthermore, molecular dynamics simulations demonstrate the stability of the ligand when interacting with targeted proteins.● The research investigates the presence of TPO-R on stem cell-derived endothelial cells, shedding insight into the ability of EPAG TPO-mimetic to promote angiogenesis and vasculature formation.● The study revealed that EPAG has the potential to protect against UVB-induced radiation damage and stimulate stem cell growth.What is the implications?The study emphasizes the potential of EPAG as a promising option for addressing radiation injury and minimizing the adverse effects of radiotherapy. It could revolutionize treatments not only for thrombocytopenia but also for enhancing the growth of stem cells. Furthermore, the research deepens our understanding of EPAG's molecular mechanisms, providing valuable insights for developing future drugs and therapeutic approaches for cell therapy to treat radiation damage.

COMPARATIVE STUDY OF OXIDATIVE STRESS IN PATIENTS WITH Β -THALASSEMIA MAJOR ON DEFERASIROX VERSUS DEFEROXAMINE THERAPY.

Accumulation of iron in vital organs is increasingly challenging in clinical settings during the lifespan of thalassemia patients. Iron overload hurdle these organs to redox imbalances. Commonly used iron-chelating agents in (deferasirox and, deferoxamine) could have a positive antioxidant role. Therefore, the aim of this study was designed to compare the effects of deferasirox and, deferoxamine, iron-chelating agents in oxidative stress in patients with ß-thalassemic major. In this case series comparative study, 60 known cases of ß-thalassemic patients receiving chelating agents therapy were divided into two groups of thirty, group one consisted of 30 patients 16 male and14 female, who received oral agent deferasirox tablets at dose 20-40mg/kg. Group two consisted of 30 patients, 16 male and 14 female, on intravenous therapy with Deferoxamine at a dose of 20-50mg/kg, Another thirty healthy individuals matched with age and gender, were kept as a control group. Total antioxidant capacity (TAOC) and Malondialdehyde (MDA) were measured in all studied groups. The three groups were similar in terms of age, and gender, A statistically non-significant difference in age (p>0.05) existed between the control and patient groups (10.9±2.93; 11.2±4.1*;11.6±3.6*) respectively. The number of patients in to control group and male-to-female numbers were matched since the ratios were similar. A statistically non-significant difference in BMI (p>0.05) existed between the control and patient groups (17±2, 17.2±2, 18±2.4*) respectively. TAOC is lower in-patient groups, when compared with the control group (27.8 ± 10.7; 32.5 ± 10.2; and 79.5 ± 7 u/ml) respectively, while the MDA value is higher when compared with the control group (7.2±4.6 and, 6.6±4.42; and 0.57±0.26; nmol/ml) respectively. The TAOC in patients group on Deferoxamine, is higher, while MDA is lower than in patients on Defrasirox. The TAOC in patients was reduced and Oxidative stress was enhanced in patients with thalassemia. Deferoxamine is more effective in modulating redox status.

(S)-(-)-blebbistatin O-benzoate has the potential to improve atopic dermatitis symptoms in NC/Nga mice by upregulating epidermal barrier function and inhibiting type 2 alarmin cytokine induction.

Atopic dermatitis is a multi-pathogenic disease characterized by chronic skin inflammation and barrier dysfunction. Therefore, improving the skin's ability to form an epidermal barrier and suppressing the production of cytokines that induce type 2 inflammatory responses are important for controlling atopic dermatitis symptoms. (-)-Blebbistatin, a non-muscle myosin II inhibitor, has been suggested to improve pulmonary endothelial barrier function and control inflammation by suppressing immune cell migration; however, its efficacy in atopic dermatitis is unknown. In this study, we investigated whether (S)-(-)-blebbistatin O-benzoate, a derivative of (-)-blebbistatin, improves dermatitis symptoms in a mite antigen-induced atopic dermatitis model using NC/Nga mice. The efficacy of the compound was confirmed using dermatitis scores, ear thickness measurements, serum IgE levels, histological analysis of lesions, and filaggrin expression analysis, which is important for barrier function. (S)-(-)-Blebbistatin O-benzoate treatment significantly reduced the dermatitis score and serum IgE levels compared to those in the vehicle group (p < 0.05). Furthermore, the histological analysis revealed enhanced filaggrin production and a decreased number of mast cells (p < 0.05), indicating that (S)-(-)-blebbistatin O-benzoate improved atopic dermatitis symptoms in a pathological model. In vitro analysis using cultured keratinocytes revealed increased expression of filaggrin, loricrin, involucrin, and ceramide production pathway-related genes, suggesting that (S)-(-)-blebbistatin O-benzoate promotes epidermal barrier formation. Furthermore, the effect of (S)-(-)-blebbistatin O-benzoate on type 2 alarmin cytokines, which are secreted from epidermal cells upon scratching or allergen stimulation and are involved in the pathogenesis of atopic dermatitis, was evaluated using antigens derived from mite feces. The results showed that (S)-(-)-blebbistatin O-benzoate inhibited the upregulation of these cytokines. Based on the above, (S)-(-)-blebbistatin O-benzoate has the potential to be developed as an atopic dermatitis treatment option that controls dermatitis symptoms by suppressing inflammation and improving barrier function by acting on multiple aspects of the pathogenesis of atopic dermatitis.

A Novel Approach to Integrate Human Biomonitoring Data with Model Predicted Dietary Exposures: A Crop Protection Chemical Case Study Using Lambda-Cyhalothrin.

The appropriate use of human biomonitoring data to model population chemical exposures is challenging, especially for rapidly metabolized chemicals, such as agricultural chemicals. The objective of this study is to demonstrate a novel approach integrating model predicted dietary exposures and biomonitoring data to potentially inform regulatory risk assessments. We use lambda-cyhalothrin as a case study, and for the same representative U.S. population in the National Health and Nutrition Examination Survey (NHANES), an integrated exposure and pharmacokinetic model predicted exposures are calibrated to measurements of the urinary metabolite 3-phenoxybenzoic acid (3PBA), using an approximate Bayesian computing (ABC) methodology. We demonstrate that the correlation between modeled urinary 3PBA and the NHANES 3PBA measurements more than doubled as ABC thresholding narrowed the acceptable tolerance range for predicted versus observed urinary measurements. The median predicted urinary concentrations were closer to the median measured value using ABC than using current regulatory Monte Carlo methods.

Differential effects of iron chelators on iron burden and long-term morbidity and mortality outcomes in a large cohort of transfusion-dependent ß-thalassemia patients who remained on the same monotherapy over 10 years.

We conducted a retrospective cohort study on 663 transfusion-dependent ß-thalassemia patients receiving the same iron chelation monotherapy with deferoxamine, deferiprone, or deferasirox for up to 10 years (median age 31.8 years, 49.9 % females). Patients on all three iron chelators had a steady and significant decline in serum ferritin over the 10 years (median deferoxamine: -170.7 ng/mL, P = 0.049, deferiprone: -236.7 ng/mL, P = 0.001; deferasirox: -323.7 ng/mL, P < 0.001) yet had no significant change in liver iron concentration or cardiac T2*; while noting that patients generally had low hepatic and cardiac iron levels at study start. Median absolute, relative, and normalized changes were generally comparable between the three iron chelators. Patients receiving deferasirox had the highest morbidity and mortality-free survival probability among the three chelators, although the difference was only statistically significant when compared with deferoxamine (P = 0.037). On multivariate Cox regression analysis, there was no significant association between iron chelator type and the composite outcome of morbidity or mortality. In a real-world setting, there is comparable long-term iron chelation effectiveness between the three available iron chelators for patients with mild-to-moderate iron overload.

Haploidentical hematopoietic stem cell transplantation as a first-line treatment for paediatric severe aplastic anemia: a single-center research.

MRD-HSCT is the first-line therapy for children with SAA, while it is not easy to find a compatible donor due to the Chinese one-child policy. IST has a high recurrence rate, a risk of clonal transformation. Thus, Haplo-HSCT, as a first-line treatment, has gradually attracted clinicians' attention. To evaluate the efficacy of Haplo-HSCT in children with SAA, we performed a retrospective study (2006.06-2021.01) of 210 patients with AA who received HSCT or IST in Beijing Children's Hospital. The OS and FFS rates were analyzed to evaluate the efficacy of Haplo-HSCT and IST. We found that from 2006 to 2021, 3- and 5-year cumulative survival rates were both 85.3% in the first-line Haplo group, 98.1% and 96.8% in the first-line IST group, both 85.7% in the ATG group (P = 0.866), both 100% in the ATG + TPO group (P = 0.016), and 99.1% and 97.2% in the ATG + eltrombopag group (P = 0.056). 3- and 5-year cumulative FFS rates were both 85.3% in the first-line Haplo-HSCT group and 67.5% and 66.2% in the first-line IST group (P = 0.033). Therefore, we believe that Haplo-HSCT can be a first-line treatment for paediatric SAA.

[Efficacy and safety of eltrombopag in the treatment of primary immune thrombocytopenia: real-world data from a single medical center].

Objective: This study aimed at investigating the efficacy and safety of eltrombopag in the treatment of adult primary immune thrombocytopenia (ITP) and evaluated the factors influencing its efficacy and side effects. Methods: A total of 198 patients with adult ITP who were admitted to Tianjin Medical University General Hospital between January 2018 and March 2022 were retrospectively analyzed. The efficacy of each starting dose of eltrombopag was evaluated, and adverse events were analyzed. The factors influencing efficacy were investigated, including sex, age, adult ITP type, platelet antibodies, and combined drug treatments. Results: Of the 198 patients, 70 males and 128 females with a median age of 45 years (18-88 years) were included; 130 (65.7%) had newly diagnosed adult ITP, 25 (12.6%) had persistent adult ITP, and 43 (21.7%) had chronic adult ITP. The bleeding event scores at baseline were assessed; 84.3% had scores of<4 and 15.7% had scores of ≥4. The eltrombopag response rate (initial response) at 6 weeks was 78.8% (complete response [CR]: 49.0%; CR1: 14.6%; CR2: 15.2%). The median response time to eltrombopag was 7 (7, 14) days. The initial response rates to 25, 50, and 75 mg eltrombopag were 74.1%, 85.9%, and 60.0%, respectively (P=0.031). The initial response rate to the 50 mg dose was significantly higher than that of the 25-mg and 75-mg doses. Two patients received 100 mg as the starting dose, and their initial response was 0. Regarding dose adjustment, 70.7% of the patients remained on the starting dose, 8.6% underwent dose adjustment to 50 mg, and 6.1% underwent dose adjustment to 75 mg. Another two patients underwent dose adjustment to 100 mg. After dose adjustment, the persistent response rates were 83.6%, 85.3%, and 85.7% for the 25-, 50-, and 75-mg doses, respectively, with no significant difference. After dose adjustment, the sustained efficacy rate for the 100-mg dose (4 patients) was 100.0%. After 6 weeks of treatment with eltrombopag, the overall bleeding score of patients with ITP decreased. The number of patients with a score of ≥4 decreased to 0, the number of patients with a score of<4 decreased, and there was no significant change in the number of patients with a score of 1-2. The most common adverse event associated with eltrombopag was impaired liver function (7.7%). No thrombosis events or other adverse events were observed. ITP type and number of megakaryocytes significantly affected the initial response to eltrombopag. The initial response rates to eltrombopag for newly diagnosed adult ITP, persistent adult ITP, and chronic adult ITP were 85.3%, 56.0%, and 76.2%, respectively (P=0.003). For megakaryocytes, the initial response rates were 61.8%, 87.1%, and 84.3% (P=0.009) for the decreased, normal, and increased megakaryocyte groups, respectively. Conclusion: Eltrombopag, as a second-line or higher treatment for adult ITP, has a rapid onset of action and good safety. The initial response rate is significantly higher with a dose of 50 mg than with a dose of 25 mg. Patients with newly diagnosed ITP and those with normal or increased megakaryocyte numbers have a higher initial response rate to eltrombopag.

Sensitive SERS assay for L-cysteine based on functionalized silver nanoparticles.

L-cysteine, an indispensable amino acid present in natural proteins, plays pivotal roles in various biological processes. Consequently, precise and selective monitoring of its concentrations is imperative. Herein, we propose a Surface-enhanced Raman Scattering (SERS) sensor for detecting L-cysteine based on the anti-aggregation of 4-mercaptobenzoic acid (4-MBA) and histidine (His) functionalized silver nanoparticles (Ag NPs). The presence of Hg2+ ions can induce the aggregation of Ag NPs@His@4-MBA due to the unique nanostructures of Ag NPs@His@4-MBA, resulting in a robust SERS intensity of 4-MBA. However, in the presence of L-cysteine, the stronger affinity between L-cysteine and Hg2+ reduces the concentration of free Hg2+, causing the dispersion of the aggregated functionalized Ag NPs and the reduction of the SERS signal intensity of 4-MBA. The developed SERS platform demonstrates excellent performance with a low detection limit of 5 nM (S/N = 3) and linear detection capabilities within the range of 0.01-100 µM for L-cysteine. Additionally, the method was successfully employed for the determination of L-cysteine in spiked serum samples, yielding recoveries ranging from 95.0 % to 108.1 % with relative standard deviations of less than 3.3 %. This study not only presents a novel approach for fabricating highly sensitive and specific SERS biosensors for biomolecule detection but also offers a significant strategy for the development and construction of SERS substrates using anti-aggregation design.

UPLC-ESI-Q-TOF-MS/MS based metabolomics investigation on chemical constituent consistency of Zhenwu Decoction before and after compatibility.

Zhenwu Decoction (ZWD), a classic formula from Zhang Zhongjing's "Treatise on Typhoid Fever" in the Han Dynasty, consists of five traditional Chinese medicines: Aconiti Lateralis Radix Praeparata (ALRP), Paeoniae Radix Alba, Poria Cocos, Ginger, and Rhizoma Atractylodis Macrocephalae. To evaluate the chemical constituent consistency of ZWD before and after compatibility, an ultra-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry was established to comprehensively study the constituents of ZWD. By normalizing the peak area, the pairwise compatibility of ALRP and the other four medicinal herbs, as well as the compatibility of the entire formula were studied, respectively. Multivariate statistical analysis was used to identify the differences. The processed data were analyzed by principal component analysis and supervised orthogonal partial least squared discriminant analysis, and an S-plot was generated to compare the differences in the chemical composition of the two types of decoction samples. The results showed that during the decoction process of ZWD, a total of seven components were recognized as differential compounds before and after compatibility of ZWD, namely 6-gingerol, zingerone, benzoylhypaconine, hypaconitine, benzoylaconine, paeoniflorin and fuziline. The results of this study provide basic data reference for understanding the law of ZWD compatibility and are valuable for the compatibility study of other herbal medicines.

Eltrombopag can promote platelet implantation after allogeneic hematopoietic stem cell transplantation as safely and similarly to thrombopoietin.

Background: Eltrombopag has demonstrated efficacy in treating low platelet (PLT) levels, but it remains unclear whether eltrombopag can promote PLT engraftment after hematopoietic stem cell transplantation (HSCT). Methods: Forty-one HSCT patients received eltrombopag 50 mg/d from +1 day until PLT >50 × 109/L or 1 month after HSCT. Fifty-one patients in the same period received thrombopoietin (TPO) to promote PLT graft after HSCT and served as a control group. Results: A total of 51 patients who applied TPO during the same period were treated as a control. In the eltrombopag group, the median time to white blood cells (WBC) graft was 12 days (range, 10-17 days) and the PLT graft was 15 days (range, 10-30 days), whereas for the patients in the TPO group, the median time to WBC and PLT graft was 12 days (range, 9-23 days) and 15.5 days (range, 9-41 days), respectively. In the first month after HSCT, the median WBC count in the eltrombopag group was 4.41 × 109/L (range, 0.87-40.01 × 109/L) and the median PLT was 89x109/L (range, 30-401 × 109/L); the median WBC and PLT \counts in the TPO group were 4.65 × 109/L (range, 0.99-23.63 × 109/L) and 86 × 109/L (range, 5-512 × 109/L), respectively. Patients in the TPO or eltrombopag group did not experience serious side effects after drug administration, and the difference in side effects on liver and kidney function between the two groups was not statistically significant. Conclusion: Eltrombopag is safe and similarly promotes platelet engraftment to thrombopoietin after allogeneic HSCT.

SERS Microsensors for the Study of pH Regulation in Cystic Fibrosis Patient-Derived Airway Cultures.

Acidification of the airway surface liquid in the respiratory system could play a role in the pathology of Cystic Fibrosis, but its low volume and proximity to the airway epithelium make it a challenging biological environment in which to noninvasively collect pH measurements. To address this challenge, we explored surface enhanced Raman scattering microsensors (SERS-MS), with a 4-mercaptobenzoic acid (MBA) pH reporter molecule, as pH sensors for the airway surface liquid of patient-derived in vitro models of the human airway. Using air-liquid interface (ALI) cultures to model the respiratory epithelium, we show that SERS-MS facilitates the optical measurement of trans-epithelial pH gradients between the airway surface liquid and the basolateral culture medium. SERS-MS also enabled the successful quantification of pH changes in the airway surface liquid following stimulation of the Cystic Fibrosis transmembrane conductance regulator (CFTR, the apical ion channel that is dysfunctional in Cystic Fibrosis airways). Finally, the influence of CFTR mutations on baseline airway surface liquid pH was explored by using SERS-MS to measure the pH in ALIs grown from Cystic Fibrosis and non-Cystic Fibrosis donors.

Synthesis, docking study, and antitumor evaluation of benzamides and oxadiazole derivatives of 3-phenoxybenzoic acid as VEGFR-2 inhibitors.

Current chemotherapeutic agents have several limitations, including lack of selectivity, the development of undesirable side effects, and chemoresistance. As a result, there is an unmet need for the development of novel small molecules with minimal side effects and the ability to specifically target tumor cells. A new series of 3-phenoxybenzoic acid derivatives, including 1,3,4-oxadiazole derivatives (4a-d) and benzamides derivatives (5a-e) were synthesized; their chemical structures were confirmed by Fourier-transform infrared spectroscopy, 1H nuclear magnetic resonance (NMR), 13C NMR, and mass spectra; and various physicochemical properties were determined. The antiproliferative activities of the new derivatives were evaluated by means of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Three compounds (4b, 4c, and 4d) exhibited cytotoxicity against two of the three cell lines tested, five compounds (3, 4a, 5a, 5b, and 5e) were toxic to one cell line, while two compounds (5c and 5d) were not cytotoxic to any of the three cell lines tested in the current study. Based on docking scores, MTT assay findings, and vascular endothelial growth factor receptor 2 (VEGFR-2) kinase activity data, Compound 4d was selected for further biological investigation. Flow cytometry was used to determine the mode of cell death (apoptosis vs. necrosis) and the effect on cell cycle progression. Compound 4d arrested HepG2 hepatocellular carcinoma cells in the G2/M phase and activated both the intrinsic and extrinsic apoptosis pathways. In conclusion, Compound 4d has shown promising results for future research as a potent VEGFR-2 tyrosine kinase inhibitor.

Target-site and non-target-site resistance mechanisms confer mesosulfuron-methyl resistance in Alopecurus aequalis.

BACKGROUND: Shortawn foxtail (Alopecurus aequalis Sobol.) is a noxious weed in China. The resistance of A. aequalis developed rapidly due to the long-term application of acetolactate synthase (ALS)-inhibiting herbicides. Here, a suspected mesosulfuron-methyl-resistant A. aequalis population, Aa-R, was collected from a wheat field in China. RESULTS: A dose‒response test showed that the Aa-R population has evolved a high level of resistance to mesosulfuron-methyl, and its growth was suppressed by imazamox, pyroxsulam and bispyribac-sodium. ALS gene sequence analysis revealed that a known resistance-related mutation (Pro-197-Thr) was present in the Aa-R population. Moreover, ALS gene overexpression was detected in the Aa-R population. The mesosulfuron-methyl resistance could be reversed by cytochrome P450 monooxygenase (CYP450) and glutathione S-transferase (GST) inhibitors. In addition, enhanced metabolism of mesosulfuron-methyl was detected in the Aa-R population compared with the susceptible population. NADPH-cytochrome P450 reductase and GST activities were strongly inducible in the Aa-R population. One CYP450 gene, CYP74A2, and one GST gene, GST4, were constitutively upregulated in the Aa-R population. Molecular docking results showed the binding affinity of CYP74A2 and GST4 for the tested ALS-inhibiting herbicides, respectively. CONCLUSION: This study confirmed that target-site resistance and non-target-site resistance involving CYP450 and GST were the main mechanisms involved in resistance in the mesosulfuron-methyl-resistant A. aequalis population.

[Two new benzyl-benzoate glucosides from Plumeria rubra].

The components with hypoglycemic activity in Plumeria rubra were isolated and purified by various column chromatography techniques and activity tracing methods. The physical and chemical properties of all the purified monomer compounds were characterized and analyzed, and a total of six compounds were isolated and identified, including 6″-acetyl-6-hydroxy-benzyl-benzoate-2-O-ß-D-glucoside(1), 6-acetyl-6-hydroxy-benzyl-benzoate-2-O-ß-D-glucoside-(1→6″)-ß-D-glucoside(2), 2-hydroxy-6-methoxy-benzyl-benzoate-2-O-ß-D-glucoside(3), 6-hydroxy-benzyl-benzoate-2-O-ß-D-glucoside(4), 6-hydroxy-benzyl-benzoate-2-O-ß-D-glucoside-(1→6″)-ß-D-glucoside(5), and 6-hydroxy-benzyl-benzoate-2-O-ß-D-glucoside-(1→6″)-ß-D-xyloside(6). Compounds 1 and 2 were new compounds, and compounds 3-6 were isolated from Plumeria for the first time. The α-glucosidase inhibitory activity of six identified compounds was tested. The results show that compounds 1-6 show certain inhibitory activity with an IC_(50) value ranging from 8.2 to 33.5 µmol·L~(-1).

Systematic evaluation of benzoylation for liquid chromatography-mass spectrometry analysis of different analyte classes.

LC-MS is an indispensable tool for small molecule analysis in many fields; however, many small molecules require chemical derivatization to improve retention on commonly used reversed-phase columns and increase ionization. Benzoyl chloride (BzCl) derivatization is commonly used for derivatization of primary and secondary amines and phenolic alcohols, though evidence exists that with proper reaction conditions (i.e., specific bases), other hydroxyl groups may be derivatized too. Previous studies have examined BzCl concentration, reaction times, and reaction temperatures for derivatization of amines and phenols for LC-MS analysis; however, use of different bases, base concentration, and extending to conditions to hydroxyl groups for LC-MS analysis has not been well-studied. To address this understudied area and identify reaction conditions for both amino and hydroxyl groups, we performed a systematic study of reaction conditions on multiple classes of potential targets. For selected derivatization methods, detection limits and performance in a variety of biological matrices were assessed. Results highlight the importance of tailoring derivatization methods for a given application as they varied by molecule and/or molecule class. Compared to the standard BzCl method commonly used, alternative methods were identified to better derivatize challenging analytes (glucosamine, choline, cortisol, uridine, cytidine) with detection limits reaching 1100, 9, 38, 170, and 67 nM compared to undetectable, 170, 86, 1000, and 86 nM respectively. Sub-nanomolar detection limits were achieved for norepinephrine with alternative derivatization approaches. Improved derivatization methods for several classes and molecules including nucleosides, steroids, and molecules containing hydroxyl groups were also identified.

Toxic effect and mechanism of ß-cypermethrin and its chiral isomers on HTR-8/SVneo cells.

Beta-cypermethrin (ß-CYP) consists of four chiral isomers, acting as an environmental estrogen and causing reproductive toxicity, neurotoxicity, and dysfunctions in multiple organ systems. This study investigated the toxic effects of ß-CYP, its isomers, metabolite 3-phenoxybenzoic acid (3-PBA), and 17ß-estradiol (E2) on HTR-8/SVneo cells. We focused on the toxic mechanisms of ß-CYP and its specific isomers. Our results showed that ß-CYP and its isomers inhibit HTR-8/SVneo cell proliferation similarly to E2, with 100 µM 1S-trans-αR displaying significant toxicity after 48 h. Notably, 1S-trans-αR, 1R-trans-αS, and ß-CYP were more potent in inducing apoptosis and cell cycle arrest than 1R-cis-αS and 1S-cis-αR at 48 h. AO/EB staining and flow cytometry indicated dose-dependent apoptosis in HTR-8/SVneo cells, particularly at 100 µM 1R-trans-αS. Scratch assays revealed that ß-CYP and its isomers variably reduced cell migration. Receptor inhibition assays demonstrated that post-ICI 182780 treatment, which inhibits estrogen receptor α (ERα) or estrogen receptor ß (ERß), ß-CYP, its isomers, and E2 reduced HTR-8/SVneo cell viability, whereas milrinone, a phosphodiesterase 3 A (PDE3A) inhibitor, increased viability. Molecular docking studies indicated a higher affinity of ß-CYP, its isomers, and E2 for PDE3A than for ERα or ERß. Consequently, ß-CYP, its isomers, and E2 consistently led to decreased cell viability. Transcriptomics and RT-qPCR analyses showed differential expression in treated cells: up-regulation of Il24 and Ptgs2, and down-regulation of Myo7a and Pdgfrb, suggesting the PI3K-AKT signaling pathway as a potential route for toxicity. This study aims to provide a comprehensive evaluation of the cytotoxicity of chiral pesticides and their mechanisms.