Carboxylesterase Activity Research Articles

Continuously increased generation of ROS in human plasma after cardiac arrest as determined by Amplex Red oxidation

Oxidative stress is believed to be a major cause of injury after cardiac arrest (CA). While the effects of ROS generated within tissues have been extensively investigated, the potential of plasma-generated ROS in contributing to CA pathology has not been examined. We utilized Amplex Red (AR) to measure the real time-generation of ROS in isolated plasma from human CA patients. We first used post-CA rat plasma to identify interfering factors for AR oxidation, and then applied this knowledge to analyze human plasma samples, accounting for the identified confounders. We found significantly increased AR oxidation rates lasting for 4 h in post-CA rat plasma compared to baseline. AR oxidation was unchanged with removal of horseradish peroxidase or addition of catalase. However, adding carboxylesterase inhibitors significantly decreased AR oxidation in rat plasma, which implicated increased carboxylesterase activity, not ROS leading to increased AR oxidation. AR oxidation rates were also significantly increased in human CA patient plasma compared to control and this increase persisted even with carboxylesterase inhibition, suggesting continuously increased ROS-generation within plasma post-CA in humans. The increased ROS generation may be one major source of injury post-CA that may be mitigated with antioxidative therapeutic strategies that can manage the ROS systemically generated in plasma over time. KEY POLICY HIGHLIGHTS We examined the potential of plasma as a source of ROS generation post-cardiac arrest Rat cardiac arrest was used to guide the application of Amplex Red in human plasma ROS generation in plasma is significantly increased after cardiac arrest in humans Scavenging excessive ROS in post-resuscitation plasma may improve outcomes of patients

Sublethal Effects of Neonicotinoid Insecticides on the Development, Body Weight and Economic Characteristics of Silkworm.

Silkworm Bombyx mori (L.) (Lepidoptera: Bombycidae) is a critical insect for silk producers, but the inappropriate application of insecticides negatively affects the physiology and behavior of silkworms. This study found that the effects of neonicotinoid insecticides applied using two spraying methods on the growth and development of silkworms were different: the median lethal concentration (LC50) values of two pesticides applied using the leaf-dipping method were 0.33 and 0.83 mg L-1 and those of two pesticides applied using the quantitative spraying method were 0.91 and 1.23 mg kg-1. The concentration of pesticides on the mulberry leaves did not decrease after their application using the quantitative spraying method, and a uniform spraying density was observed after the mulberry leaves were air-dried (no liquid) under realistic conditions. We then treated silkworms with the quantitative spraying method and leaf-dipping method. The treatment of silkworm larvae with imidacloprid and thiamethoxam at sublethal concentrations significantly prolonged the development time and significantly decreased the weight and pupation rate, as well as economic indicators of enamel layers and sputum production. Thiamethoxam treatment significantly increased the activities of carboxylesterase (CarE) and glutathione-S-transferase (GST). The activity of CarE and GST increased, decreased, and then increased, and the highest activity was detected on the 10th and 12th days. Thiamethoxam exposure significantly elevated the transcription levels of CarE-11, GSTe3 and GSTz2 and induced DNA damage in hemocytes. This study confirmed that the quantitative spray method is more stable than the leaf-dipping method. Moreover, imidacloprid and thiamethoxam treatment affected the economy and indexes of silkworms and induced changes in detoxification enzymes and DNA damage in silkworms. These results provide a basis for understanding the mechanism of the sublethal effects of insecticides on silkworms.

Effects of dietary fluoranthene on tissue-specific responses of carboxylesterases, acetylcholinesterase and heat shock protein 70 in two forest lepidopteran species

In this study, responses of carboxylesterases, acetylcholinesterase, and stress protein Hsp70 were examined in the midgut and midgut tissue, and brain of fifth instar larvae of Lymantria dispar L. and Euproctis chrysorrhoea L. following chronic exposure to dietary fluoranthene. Specific carboxylesterase activity increased significantly in the midgut tissue of E. chrysorrhoea larvae treated with a lower fluoranthene concentration. The specific patterns of isoforms expression, recorded in larvae of both species, enable efficient carboxylesterase activity as a significant part of defense mechanisms. Increased Hsp70 concentration in the brain of L. dispar larvae points to a response to the proteotoxic effects of a lower fluoranthene concentration. Decreased Hsp70 in the brain of E. chrysorrhoea larvae in both treated groups can suggest induction of other mechanisms of defense. The results indicate the importance of the examined parameters in larvae of both species exposed to the pollutant, as well as their potential as biomarkers.

Risk Assessment of Fluxametamide Resistance and Fitness Costs in Fall Armyworm (Spodoptera frugiperda).

The fall armyworm (FAW), Spodoptera frugiperda, is one of the most devastating invasive polyphagous pests, which has attracted recent global attention by developing resistance to various insecticidal active ingredients with independent mode of action. Fluxametamide, a newly commercialized isoxazoline insecticide, is exceptionally selective towards several lepidopteran pests. The present study aimed to evaluate resistance risk in FAW to fluxametamide and the fitness costs associated with fluxametamide resistance. A field-collected and genetically mixed population of FAW was artificially selected through continuous exposure to fluxametamide. After successive selection of 10 generations, there was no obvious increase in the LC50 (RF: 2.63-fold). The realized heritability (h2) of fluxametamide resistance was estimated as h2 = 0.084 using a quantitative genetic approach. Compared with the susceptible F0 strain, the Flux-SEL (F10) strain of FAW displayed no significant cross-resistance to broflanilide, chlorantraniliprole, fipronil, indoxacarb, lambda cyhalothrin, spinetoram, and tetraniliprole, except emamectin benzoate (RF: 2.08-fold). Increased activity of glutathione S-transferase (ratio 1.94) was observed in the Flux-SEL (F10) strain of FAW, while the cytochrome P450 and carboxylesterase activities were not altered. The fluxametamide-selection significantly affected the development and reproductive traits of FAW with a lower R0, T and relative fitness (Rf = 0.353). The results alluded that the risk of fluxametamide resistance evolution in FAW is relatively lower; however, proactive implementation of resistance management approaches should be done to maintain the field efficacy of fluxametamide against FAW.

Sensory irritation to methylparaben is caused by its low metabolism in the skin.

Sensitive skin is a well- known skin condition showing sensory irritation to daily used products such as cosmetics or pharmaceuticals, possibly containing sensory irritants. Methylparaben (MP), widely used as a preservative, is a representative sensory irritant and hydrolyzed in the skin. We aimed to clarify the relationship between MP sensory irritation and MP hydrolysis. First, we investigated the percutaneous penetration and hydrolysis of MP by using an ex vivo pig skin system and confirmed that topically applied MP was immediately hydrolyzed to p-hydroxybenzoic acid (PHBA). We next evaluated whether MP or PHBA causes sensory irritation using a well-used stinging test in human skin and found that MP, but not PHBA, induced irritation. Additionally, MP, but not PHBA, increased intracellular calcium in cultured TRPA1-expressed HEK293 cells, supporting the stimulatory activity of MP. Five and 10 individuals with sensitive and non-sensitive skin, respectively, were selected by a questionnaire and stinging test. In their biopsied skin samples, MP hydrolytic activity was significantly lower in sensitive than non-sensitive skin. Finally, we examined the activity of carboxylesterase (CES), which promptly hydrolyzes MP to PHBA. By using specific inhibitors of CES and CES2, we found that CES1 was responsible for MP metabolism. Our study suggests that low skin metabolism of topical agents is one of the causes of skin sensory irritation and resultant sensitive skin.

Determination of Intracellular Esterase Activity Using Ratiometric Raman Sensing and Spectral Phasor Analysis

Carboxylesterases (CEs) are a class of enzymes that catalyze the hydrolysis of esters in a variety of endogenous and exogenous molecules. CEs play an important role in drug metabolism, in the onset and progression of disease, and can be harnessed for prodrug activation strategies. As such, the regulation of CEs is an important clinical and pharmaceutical consideration. Here, we report the first ratiometric sensor for CE activity using Raman spectroscopy based on a bisarylbutadiyne scaffold. The sensor was shown to be highly sensitive and specific for CE detection and had low cellular cytotoxicity. In hepatocyte cells, the ratiometric detection of esterase activity was possible, and the result was validated by multimodal imaging with standard viability stains used for fluorescence microscopy within the same cell population. In addition, we show that the detection of localized ultraviolet damage in a mixed cell population was possible using stimulated Raman scattering microscopy coupled with spectral phasor analysis. This sensor demonstrates the practical advantages of low molecular weight sensors that are detected using ratiometric Raman imaging and will have applications in drug discovery and biomedical research.

Heavy metal(loid) effect on multi-biomarker responses in apex predator: Novel assays in the monitoring of white stork nestlings

The goal of the present study was to investigate differences in biomarker responses related to metal(loid)s in white stork (Ciconia ciconia) nestling's blood from continental Croatia. To achieve this, a battery of biomarkers that can be affected by environmental pollutants, including metal(loid)s, was assessed (esterase activity, fluorescence–based oxidative stress biomarkers, metallothionein levels, glutathione–dependent enzyme activity). The research was conducted during the white stork breeding season in diverse areas (a landfill, industrial and agricultural sites, and an unpolluted area). White storks' nestlings near the landfill exhibited reduced carboxylesterase (CES) activity, elevated glutathione (GSH) concentration, as well as high Pb content in the blood. Increased As and Hg concentrations in blood were attributable to environmental contamination in agricultural area and an assumed unpolluted area, respectively. Furthermore, agricultural practices appeared to affect CES activity, as well as elevate Se levels. In addition to the successful implementation of biomarkers, present research showed that agricultural areas and a landfill are areas with increased metal(loid) levels possibly causing adverse effects on the white storks. This first–time heavy metal and metalloid analyses in the white stork nestlings from Croatia point to the necessary monitoring and future assessments of pollution impact to prevent irreversible adverse effects.

A Turn-On Lipid Droplet-Targeted Near-Infrared Fluorescent Probe with a Large Stokes Shift for Detection of Intracellular Carboxylesterases and Cell Viability Imaging.

Carboxylesterases (CEs) play important physiological roles in the human body and are involved in numerous cellular processes. Monitoring CEs activity has great potential for the rapid diagnosis of malignant tumors and multiple diseases. Herein, we developed a new phenazine-based "turn-on" fluorescent probe DBPpys by introducing 4-bromomethyl-phenyl acetate to DBPpy, which can selectively detect CEs with a low detection limit (9.38 × 10-5 U/mL) and a large Stokes shift (more than 250 nm) in vitro. In addition, DBPpys can also be converted into DBPpy by carboxylesterase in HeLa cells and localized in lipid droplets (LDs), emitting bright near-infrared fluorescence under the irradiation of white light. Moreover, we achieved the detection of cell health status by measuring the intensity of NIR fluorescence after co-incubation of DBPpys with H2O2-pretreated HeLa cells, indicating that DBPpys has great potential applications for assessing CEs activity and cellular health.

Effects of Honeysuckle Varieties on Protective and Detoxifying Enzyme Activities in Heterolocha Jinyinhuaphaga Chu (Lepidoptera: Geometridae) Larvae.

Investigating the effects of various host plants on protective and detoxifying enzyme activities in insects could provide insights into the adaptation mechanisms of insects to host plants. In the present study, we measured superoxide dismutase (SOD), peroxidase (POD), catalase(CAT), carboxylesterase(CarE), acetylcholinesterase (AchE), and glutathione S-transferase (GST) activity levels in Heterolocha jinyinhuaphaga Chu (Lepidoptera: Geometridae) larvae fed on four honeysuckle varieties (wild variety, Jiufeng 1, Xiangshui 1, and Xiangshui 2). The results showed that levels of SOD, POD, CAT, CarE, AchE, and GST activities in H. jinyinhuaphaga larvae fed on the four honeysuckle varieties differed. The enzyme activity levels were the highest when larvae were fed on the wild variety, followed by Jiufeng 1 and Xiangshui 2, and the lowest when fed on Xiangshui 1. Furthermore, the enzyme activity levels increased with an increase in larval age. According to the results of two - way analysis of variance, the interaction between host plants and larval age had no significant effect on SOD, POD, CAT, CarE, AchE, and GST activities in H. jinyinhuaphaga larvae (p ˃0.05).

Effects of Phenanthrene Exposure on the B-esterases Activities of Octopus maya (Voss and Solís Ramírez, 1996) Embryos

No ecotoxicological information exists on phenanthrene (Phe) exposure in cephalopods, animals of commercial and ecological importance. This study investigated the effect of Phe on two B-esterases, Acetylcholinesterase (AChE) and Carboxylesterases (CbE), in Octopus maya embryos. Octopus embryos were exposed to different treatments: control (seawater), solvent control (seawater and DMSO 0.01%), 10 and 100 µg/L of Phe. AChE and CbE activities were measured at different developmental stages (blastula, organogenesis, and growth). B-esterase activities increased in control and solvent control as the embryos developed, showing no statistically significant differences between them. On the other hand, the embryos exposed to Phe had significant differences from controls, and between the high and low concentrations. Our results indicate that B-esterases are sensitive biomarkers of exposure to Phe in O. maya. Still, complementary studies are needed to unravel the toxicodynamics of Phe and the implications of the found inhibitory effect in hatched organisms.

Influence of temperature on the biomarker responses of bullfrog tadpoles (Lithobates catesbeianus) to 2-hydroxyatrazine exposure

The influence of temperature (25 and 32 °C) on the biomarker responses of bullfrog tadpoles (Lithobates catesbeianus) to different concentrations of the atrazine metabolite 2-hydroxyatrazine (2-HA, 0, 10, 50 and 200 ng.L−1, 16 days), was evaluated. Temperature affected the activities of superoxide dismutase, glutathione S-transferase and acetylcholinesterase. The activities of catalase, glutathione peroxidase, glucose-6-phosphate dehydrogenase and carboxylesterase presented no alterations. Frequencies of micronuclei and nuclear abnormalities were also not altered. 2-HA decreased SOD activity at 25 °C and caused histopathological changes in the liver and the kidney at both temperatures, with the kidney being more affected by the combination of higher temperature and 2-HA exposure, presenting glomerular shrinkage and an increase in Bowman's space. Our results indicate that at environmentally relevant concentrations, 2-HA can cause changes in biomarker responses as well as in the morphology of liver and kidney in L. catesbeianus tadpoles. Temperature has an important influence on biomarker response and histopathological alterations.

Enhancing the Toxicity of Cypermethrin and Spinosad against Spodoptera littoralis (Lepidoptera: Noctuidae) by Inhibition of Detoxification Enzymes.

The extensive use of wide-ranging insecticides in agricultural activities may develop resistance in insects. The dipping technique was utilized for examining changes in detoxifying enzyme levels in Spodoptera littoralis L. induced by cypermethrin (CYP) and spinosad (SPD) with and without a combination of three enzyme inhibitors: triphenyl phosphate (TPP), diethyl maleate (DEM), and piperonyl butoxide (PBO), at 70 μg/mL. PBO, DEM, and TPP showed 50% mortality against larvae at 236.2, 324.5, and 245.8 μg/mL, respectively. The LC50 value of CYP on S. littoralis larvae reduced from 2.86 μg/mL to 1.58, 2.26, and 1.96 μg/mL, while the LC50 value of SPD declined from 3.27 μg/mL to 2.34, 2.56, and 2.53, with the addition of PBO, DEM, and TPP, respectively, 24 h after treatment. Moreover, the activity of carboxylesterase (CarE), glutathione S-transferase (GST), and cytochrome P450 monooxygenase (Cyp 450) was significantly inhibited (p < 0.05) by TPP, DEM, PBO plus CYP, and SPD in S. littoralis larvae in comparison with tested insecticides alone. These findings suggested that three enzyme inhibitors play a major role in increasing the toxicity of CYP and SPD in S. littoralis and will provide insight into how to overcome insecticide resistance in insects.

The Comparative Toxicity, Biochemical and Physiological Impacts of Chlorantraniliprole and Indoxacarb on Mamestra brassicae (Lepidoptera: Noctuidae).

The cabbage moth, Mamestra brassicae, is a polyphagous pest that attacks several crops. Here, the sublethal and lethal effects of chlorantraniliprole and indoxacarb were investigated on the developmental stages, detoxification enzymes, reproductive activity, calling behavior, peripheral physiology, and pheromone titer of M. brasssicae. Methods: To assess pesticide effects, the second instar larvae were maintained for 24 h on a semi-artificial diet containing insecticides at their LC10, LC30, and LC50 concentrations. M. brassicae was more susceptible to chlorantraniliprole (LC50 = 0.35 mg/L) than indoxacarb (LC50 = 1.71 mg/L). A significantly increased developmental time was observed with both insecticides at all tested concentrations but decreases in pupation rate, pupal weight, and emergence were limited to the LC50 concentration. Reductions in both the total number of eggs laid per female and the egg viability were observed with both insecticides at their LC30 and LC50 concentrations. Both female calling activity and the sex pheromone (Z11-hexadecenyl acetate and hexadecenyl acetate) titer were significantly reduced by chlorantraniliprole in LC50 concentration. Antennal responses of female antennae to benzaldehyde and 3-octanone were significantly weaker than controls after exposure to the indoxocarb LC50 concentration. Significant reductions in the enzymatic activity of glutathione S-transferases, mixed-function oxidases, and carboxylesterases were observed in response to both insecticides.

The influence of ecological factors in the modulation of pollution biomarkers of two small pelagic marine fish

Biomarkers are useful tools for the detection of marine pollution, which is poorly monitored in the pelagic environment. In this study, we investigated the role of key biological and environmental factors on three hepatic xenobiotic biomarkers: carboxylesterases (CEs), glutathione S-transferase (GST) and catalase (CAT). Additionally, ethoxyresorufin-O-deethylase (EROD) and benzyloxy-4-[trifluoromethyl]-coumarin-O-debenzyloxylase (BFCOD) activities were determined for comparative purposes. The pelagic species targeted were the European anchovy (Engraulis encrasicolus) and the European sardine (Sardina pilchardus). The results revealed sex-dependent CE activities in sardine. CEs and GST activities were significantly affected by reproduction and, in anchovy, CE activities were also influenced by temperature. In vitro incubations revealed that the pesticide dichlorvos caused up to 90 % inhibition of basal CEs activity. This work highlights that the reproductive status, temperature and sex, modulate biomarker responses, and that anchovy would be more suitable pelagic bioindicator due to its higher in vitro sensitivity to dichlorvos and sex-independent biomarker responses.

Susceptibility to acaricides and detoxifying enzyme activity in Tetranychus gloveri Banks (Acari: Tetranychidae) populations from India

ABSTRACT Tetranychus gloveri, a recently introduced mite species in Kerala, India has now established in the state as a predominant mite pest on ornamental plants. In this study, the status of acaricide resistance and the activity of detoxification enzymes were investigated in the populations of T. gloveri collected on Adenium plants from six different commercial horticultural nurseries of Thrissur district, Kerala, India. Adulticidal bioassays were performed for fenazaquin and dicofol, while nymphicidal bioassays were conducted for spiromesifen to estimate the LC50. The field populations showed resistance ratios in the range of 1.66–14.38-fold for fenazaquin, 1.06–27.31-fold for spiromesifen and 1.22–3.65-fold for dicofol, compared to the laboratory-maintained reference population. Enzyme assays of detoxifying enzymes revealed enhanced activity of carboxylesterase by 1.03–3.52-fold and cytochrome P450 monooxygenase by 1.01–2.08-fold in the field populations. However, the role of glutathione S-transferase in the development of resistance in different field populations was insignificant. The study recorded the development of resistance in the spider mite, T. gloveri to new generation acaricides spiromesifen and fenazaquin for the first time and also confirmed the significant role of the carboxylesterases and cytochrome P450 monooxygenases in imparting resistance in T. gloveri.

Sublethal effects of chlorantraniliprole on growth, biochemical and molecular parameters in two chironomids, Chironomus kiiensis and Chironomus javanus

Pesticide residues have serious environmental impacts on rice-based ecosystems. In rice fields, Chironomus kiiensis and Chironomus javanus provide alternative food sources to predatory natural enemies of rice insect pests, especially when pests are low. Chlorantraniliprole is a substitute for older classes of insecticides and has been used extensively to control rice pests. To determine the ecological risks of chlorantraniliprole in rice fields, we evaluated its toxic effects on certain growth, biochemical and molecular parameters in these two chironomids. The toxicity tests were performed by exposing third-instar larvae to a range of concentrations of chlorantraniliprole. LC50 values at 24 h, 48 h, and 10 days showed that chlorantraniliprole was more toxic to C. javanus than to C. kiiensis. Chlorantraniliprole significantly prolonged the larval growth duration, inhibited pupation and emergence, and decreased egg numbers of C. kiiensis and C. javanus at sublethal dosages (LC10 = 1.50 mg/L and LC25 = 3.00 mg/L for C. kiiensis; LC10 = 0.25 mg/L and LC25 = 0.50 mg/L for C. javanus). Sublethal exposure to chlorantraniliprole significantly decreased the activity of the detoxification enzymes carboxylesterase (CarE) and glutathione S-transferases (GSTs) in both C. kiiensis and C. javanus. Sublethal exposure to chlorantraniliprole also markedly inhibited the activity of the antioxidant enzyme peroxidase (POD) in C. kiiensis and POD and catalase (CAT) in C. javanus. Expression levels of 12 genes revealed that detoxification and antioxidant abilities were affected by sublethal exposures to chlorantraniliprole. There were significant changes in the expression levels of seven genes (CarE6, CYP9AU1, CYP6FV2, GSTo1, GSTs1, GSTd2, and POD) in C. kiiensis and ten genes (CarE6, CYP9AU1, CYP6FV2, GSTo1, GSTs1, GSTd2, GSTu1, GSTu2, CAT, and POD) in C. javanus. These results provide a comprehensive overview of the differences in chlorantraniliprole toxicity to chironomids, indicating that C. javanus is more susceptible and suitable as an indicator for ecological risk assessment in rice ecosystems.

Chemical screening and mosquitocidal activity of essential oil derived from Mikania scandens (L.) Willd. against Anopheles gambiae Giles and their non-toxicity on mosquito predators

In-vitro chemical characterization and mosquitocidal screening of essential oil derived from Mikania scandens (L.) Willd. (Asteraceae) (CVO-MS) against the malarial vector Anopheles gambiae was investigated. GC-MS analysis evidenced a total of 12 bio-active compounds, and maximum at α-bisabolol (39.34%) followed by stigmasterol (13.45%) respectively. The larvicidal activity of CVO-MS against the malarial vector An. gambiae evidenced that the mortality rate was prominent at the maximum dosage of 1000 ppm. The Median Lethal Concentration (LC50) of CVO-MS was established at 488 ± 2.45 ppm, respectively. Enzyme inhibition assay showed that the CVO-MS delivers a significant upsurge in the level of CYP450, GST, and a decline in the level of α-β carboxylesterase activity in both the third and fourth instar (p ≤ 0.0001). The gut-histological examination of CVO-MS showed that there is severe damage in the mid-gut tissues, especially epithelial layer (EL), gut-lumen (GL), and peritrophic membrane (pM). The non-target screening against the mosquito predators (A. bouvieri, D. indicus, and third instar larvae of Tx. splendens) suggests that CVO-MS showed less toxicity as compared to Pestanal® (1 ppm) respectively. The present study has paved a new insight in understanding the bioactivity of CVO-MS as a potential larvicidal agent of malarial vector and non-toxic against mosquito predators.

Effects of Methyl Jasmonate Fumigation on the Growth and Detoxification Ability of Spodoptera litura to Xanthotoxin.

Methyl jasmonate (MeJA) is a volatile substance derived from jasmonic acid (JA), and it responds to interbiotic and abiotic stresses by participating in interplant communication. Despite its function in interplant communication, the specific role of MeJA in insect defense responses is poorly understood. In this study, we found that carboxylesterase (CarE) activities, glutathione-S-transferase (GSTs) activities, and cytochrome mono-oxygenases (P450s) content increased more after the feeding of diets containing xanthotoxin, while larvae exposed to MeJA fumigation also showed higher enzyme activity in a dose-dependent manner: lower and medium concentrations of MeJA induced higher detoxification enzyme activities than higher concentrations of MeJA. Moreover, MeJA improved the growth of larvae fed on the control diet without toxins and diets with lower concentrations of xanthotoxin (0.05%); however, MeJA could not protect the larvae against higher concentrations of xanthotoxin (0.1%, 0.2%). In summary, we demonstrated that MeJA is effective at inducing S. litura defense response, but the enhanced detoxifying ability could not overcome the strong toxins.

A novel near-infrared chemodosimeter to monitor the change of carboxylesterase in treatment of diabetes

Carboxylesterase (CE) localized in the lumen of the endoplasmic reticulum (ER) hydrolyzes many prodrugs to exert therapeutic effect, such as anticoagulant clopidogrel and anticarcinogen irinotecan. Diabetes might induce CE to show a decreasing level, and thus impact the therapy effect. Hence, it is crucial to monitor the change of CE in treatment for diabetes for using drug rationally. We attempted to develop novel near-infrared fluorescent probes to detect CE activity in the ER with high selectivity and sensitivity in cells and in vivo, and help to guide the use of CE-related medications. Moreover, the excellent chemodosimeter (Hecy-1) could be applied in detecting CE level in tumor cells and LO2 cells. In glucose-induced CE changes of LO2 cells, Hecy-1 still showed admirable imaging ability. This research may further promote the study of intracellular fine biological activities of CE and the development of diabetes diagnosis.

Associations between CES1 variants and dosing and adverse effects in children taking methylphenidate.

Methylphenidate is the most prescribed stimulant to treat attention deficit-hyperactivity disorder (ADHD). Despite its widespread usage, a fair proportion of children are classified as non-responders to the medication. Variability in response and occurrence of adverse events with methylphenidate use may be due to several factors, including drug-drug interactions as well as pharmacogenetic differences resulting in pharmacokinetic and/or pharmacodynamic variances within the general population. The objective of this study was to analyze the effect of carboxylesterase 1 (CES1) variants on the frequency of adverse effects and dosing requirements of methylphenidate in children with ADHD. This was a retrospective cohort study of children and adolescents who met the inclusion criteria and had a routine visit during the enrollment period were invited to participate. Inclusion criteria included: ADHD diagnosis by a healthcare provider, between 6 and 16 years of age at the time of permission/assent, had not previously been prescribed methylphenidate, and treatment with any methylphenidate formulation for at least three consecutive months. Three months of records were reviewed in order to assess changes in dose and frequency of discontinuing methylphenidate. Participants' ADHD symptoms, medication response, adverse effects, select vitals, and dose were extracted from the electronic health record. Saliva samples were collected by trained study coordinators. Haplotypes were assigned based on copy number in different portions of the CES1 gene. Due to limited numbers, diplotypes (combinations of two haplotypes) were grouped for analysis as CES1A1/CES1A1, CES1A1/CES1A1c and CES1A1c/CES1A1c. A total of 99 participants (n = 30 female; n = 69 male) had both clinical data and CES1 sequencing data, with an average age of 7.7 years old (range 3-15 years). The final weight-based dose in all individuals was 0.79 mg/kg/day. The most common adverse effects reported were decreased appetite (n = 47), weight loss (n = 24), and sleep problems (n = 19). The mean final weight-based dose by haplotype was 0.92 mg/kg for CES1A2/CES1A2, 0.81 mg/kg for CES1A2/CES1P1, and 0.78 mg/kg for CES1P1/CES1P1. After correction for multiple hypothesis testing, only one SNV, rs114119971, was significantly associated with weight-based dosing in two individuals. The individuals with the rs114119971 SNV had a significantly lower weight-based dose (0.42 mg/kg) as compared to those without (0.88 mg/kg; p < 0.001). Variation in CES1 activity may impact dose requirements in children who are prescribed methylphenidate, as well as other CES1 substrates. Although intriguing, this study is limited by the retrospective nature and relatively small sample size.