Expression Levels Of Cytochrome P450 Research Articles

Dihydroberberine alleviates Th17/Treg imbalance in premature ovarian insufficiency mice via inhibiting Rheb/mTOR signaling

BackgroundPremature ovarian insufficiency (POI) is an immune-related condition. Dihydroberberine (dhBBR) plays a regulatory role in maintaining the T-helper 17 (Th17)/regulatory T (Treg) cell balance. This study aimed to explore the action mechanisms of dhBBR on POI.MethodsIn vivo, female BALB/c mice were used as POI models, treated with dhBBR, or injected with recombinant interleukin (rIL)-17 and anti-CD25 monoclonal antibody. Hematoxylin and eosin staining was used to validate the model and assess the therapeutic effects of dhBBR. mRNA expression levels of cytochrome P450 (Cyp)-17a1, Cyp19a1, Cyp11a1, steroidogenic acute regulatory protein, and luteinizing hormone receptor in mouse ovaries were quantified via quantitative polymerase chain reaction (qPCR). Enzyme-linked immunosorbent assay was used to determine the cytokine and sex hormone levels. Immunohistochemical staining for cleaved-caspase 3 and Ki-67 were performed to assess ovarian cell apoptosis and proliferation. Flow cytometry was used to analyze the Th17/Treg cell balance in the ovary and spleen. In vitro cytotoxicity of dhBBR was measured using the cell counting kit-8 assay. GTP-Ras homolog enriched in brain (Rheb) activity was determined via immunofluorescence assay. Co-immunoprecipitation was performed to assess Rheb activity, Th17 or Treg induction, and binding between Rheb and mammalian target of rapamycin (mTOR) after dhBBR treatment. Flow cytometry and qPCR assays were used to verify the effect of dhBBR on CD4 + cell differentiation. Finally, Rheb/mTOR pathway activation was confirmed via western blotting of proteins, including mTOR, p-mTOR, p70S6K, p-p70S6K, 4E-BP1, and p-4E-BP1.ResultsdhBBR improved the ovarian function in a dose-dependent manner. It also decreased ovarian cell apoptosis and increased cell proliferation. It decreased Th1 and Th17 cell proportions but increased Treg cell proportions in the ovaries and spleens of POI model mice. Cell experiments revealed that dhBBR promoted CD4 + cell differentiation into Treg cells. Co-immunoprecipitation revealed Rheb as the dhBBR target that bound to mTOR. However, MHY1485 restored dhBBR-induced changes in forkhead box P3, IL-10, transforming growth factor-β1, IL-17, IL-22, retinoic acid-related orphan receptor-γt and p-mTOR levels in Th17- and Treg-induced CD4 + cells.ConclusionOverall, dhBBR targeted the Rheb/mTOR pathway to promote CD4 + cell differentiation into Treg cells and alleviate POI.

Induction of cytochrome P450 via upregulation of CAR and PXR: a potential mechanism for altered florfenicol metabolism by macranthoidin B in vivo.

Macranthoidin B (MB) is a primary active component of Flos Lonicerae. In Chinese veterinary clinics, Flos Lonicerae is frequently used in combination with florfenicol to prevent and treat infections in livestock and poultry. However, potential interactions between Flos Lonicerae and florfenicol remain unclear. To systematically study these interactions, it is crucial to investigate the individual phytochemicals within Flos Lonicerae. Therefore, MB was selected for this study to assess its effect on the pharmacokinetics of florfenicol in vivo and to explore the underlying mechanisms involved. Male Sprague-Dawley rats were administered MB (60 mg/kg BW) or sterile water orally for 7 consecutive days. On the 8th day, a single oral dose of florfenicol (25 mg/kg BW) was given. Florfenicol pharmacokinetics were analyzed using ultra-high performance liquid chromatography. The hepatic expression levels of cytochrome P450 (CYP1A2, CYP2C11, CYP3A1), UDP-glucuronosyltransferase (UGT1A1), P-glycoprotein (P-gp), and nuclear receptors, including constitutive androstane receptor (CAR), pregnane X receptor (PXR), and retinoid X receptor alpha (RXRα), were quantified via reverse transcription-quantitative polymerase chain reaction and Western blotting (WB). Hepatic CYP1A2 and CYP2C11 activities were measured using a cocktail method. Additionally, the subcellular expression and localization of CAR, PXR, and RXRαin hepatocytes was assessed using WB and immunofluorescence staining. MB significantly reduces the AUC(0-∞) and MRT(0-∞) of florfenicol. MB also markedly upregulates the mRNA and protein expression of hepatic CYP1A2 and CYP2C11, along with their catalytic activities. Substantial upregulation of CAR and PXR proteins occurs in the hepatocyte nucleus, along with significant nuclear colocalization of the transcriptionally active CAR/RXRα and PXR/RXRαheterodimers, indicating MB-induced nuclear translocation of both CAR and PXR. These findings suggest that MB-induced alterations in florfenicol pharmacokinetics, particularly its accelerated elimination, may be due to increased expression and activities of CYP1A2 and CYP2C11, with CAR and PXR potentially involved in these regulatory effects. Further investigation is yet needed to fully elucidate the clinical implications of these interactions concerning the efficacy of florfenicol in veterinary medicine.

Biochemical and genetic mechanisms in Pieris rapae (Lepidoptera: Pieridae) resistance under emamectin benzoate stress

Pieris rapae (Lepidoptera: Pieridae) poses a significant threat to Brassicaceae crops, leading to substantial losses annually. Repeated insecticide applications are widely used to protect crops and increase the resistance of P. rapae. Exploring the biochemical and molecular basis of insecticide tolerance in P. rapae is crucial for achieving effective insect suppuration and implementing resistance control strategies. In our research, emamectin benzoate (EBZ) resistance was developed in P. rapae strain through selective pressure over 15 generations. Moreover, the biochemical mechanisms underlying resistance to EBZ and its potential cross-resistance to other insecticides were studied. Additionally, the expression levels of cytochrome P450 (CYP450) and glutathione-s-transferase (GST) genes in P. rapae were quantitatively assessed upon exposure to EBZ using real-time PCR. Our data exhibited that the LC50 value of susceptible strain (Sus) and EBZ resistance strain (EBZ-R) were 0.009 and 8.09 mg/L, with a resistance ratio (RR) reaching 898.8-fold. The EBZ-R stain displayed notably low cross-resistance to lambda-cyhalothrin, spinetoram, and cypermethrin. However, it demonstrated a moderate level of cross-resistance to deltamethrin. Conversely, no cross-resistance was noted to chlorantraniliprole and indoxacarb. Notably, enzyme inhibitors of detoxification enzymes revealed that piperonyl butoxide (PBO) and diethyl maleate (DEM) enhanced the EBZ toxicity to the resistant strain, indicating the potential involvement of CYP450 and GST in avermectin resistance. A remarkable enhancement in CYP450 and GST activity was observed in the EBZ-R stain. CYP450 and GST genes are upregulated in the EBZ-R stain compared to the Sus strain, which serves as a basis for comprehending the mechanism behind P. rapae resistance to EBZ. The molecular docking analysis demonstrated that EBZ has a high binding affinity with CYP6AE120 and PrGSTS1 with docking energy values of −20.19 and −22.57 kcal/mol, respectively. Our findings offer valuable insights into crafting efficient strategies to monitor and manage resistance in P. rapae populations in Egypt.

Sex- and lifestyle-related factors are associated with altered hepatic CYP protein levels in people diagnosed with mental disorders.

In this study, we used human postmortem tissue to investigate hepatic protein expression levels of CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4 by LC‒MS/MS in a population of people suffering from mental disorders (n=171). We report hepatic protein levels of these six CYP isoforms in 171 individuals in total, and define a focused population dataset of 116 individuals after excluding 55 samples due to low Microsomal Protein Per Gram of Liver (MPPGL) yield. Postmortem decay was most likely the reason for the low MPPGL yield in the 55 samples. In the focused population, we found women to have significantly higher protein levels of CYP3A4 than men in addition to decreased CYP3A4 protein levels among obese individuals. Furthermore, MPPGL was negatively correlated with body mass index (BMI). An increase in CYP1A2 protein levels was observed among smokers and increased CYP2E1 protein levels were observed among individuals with a history of alcohol abuse. Finally, individuals who received phenobarbital (CYP3A4 inducer) had significantly higher CYP3A4 levels. In conclusion, lifestyle-related factors prevalent among people suffering from mental disorders are associated with altered CYP protein levels which may alter drug metabolism and affect the efficacy of commonly prescribed drugs. Furthermore, this investigation demonstrates that postmortem hepatic tissue can be used to study how lifestyle and effectors affect hepatic CYP-levels in a large cohort of patients. Significance Statement Using a large number of postmortem hepatic tissue specimens (n=116) originating from the autopsy of individuals diagnosed with mental disorders, we were able to show that hepatic CYP-levels were affected by alcohol, smoking, BMI, and sex and that MPPGL was affected by BMI. Theses lifestyle-related changes may alter drug metabolism and affect the efficacy of commonly prescribed drugs. It is a novel approach to use a large postmortem cohort to investigate how lifestyle and effectors affect hepatic CYP-levels.

Impact of tectoridin on the pharmacokinetics of florfenicol via targeting cytochrome P450 and P-glycoprotein of rats

Belamcanda chinensis (L.) DC, commonly used with florfenicol in Chinese veterinary clinics for respiratory tract infections, contains the major effective isoflavone, tectoridin (TEC). This study aimed to investigate the impact of TEC co-administration on the pharmacokinetics of florfenicol in vivo. Male rats received oral TEC (50 mg/kg BW) or sterile water for seven days, followed by a single oral dose of florfenicol (25 mg/kg BW) on the 8th day. Non-compartmental methods analysed the pharmacokinetics of florfenicol, while real-time reverse transcription polymerase chain reaction (RT-PCR), Western blot, and immunohistochemical analyses measured expression levels of cytochrome P450 (CYP) isoforms in the liver and P-glycoprotein (P-gp) in the jejunum. TEC significantly decreased florfenicol’s AUC(0–∞), MRT(0–∞), t 1/2z, Vz/F, and C max by 24.75%, 18.43%, 55.47%, 43.05%, and 19.48%, while increasing CLz/F by 33.33%. TEC also up-regulated hepatic CYP1A2 and CYP3A1 mRNA expression, as well as intestinal MDR1, by 1.39-fold, 1.85-fold, and 1.65-fold. This coincided with a respective increase in protein expression by 1.37-fold, 1.39-fold, and 1.43-fold. These findings suggest that TEC-induced alterations in the pharmacokinetics of florfenicol may be attributed to increased CYP and P-gp expression. Further investigations are warranted to understand the implications of these findings on the clinical effectiveness of florfenicol in veterinary practice.

PCB126 exposure during pregnancy alters maternal and fetal gene expression

Polychlorinated biphenyls (PCBs) are organic pollutants that can have lasting impacts on offspring health. Here, we sought to examine maternal and fetal gene expression differences of aryl hydrocarbon receptor (AHR)-regulated genes in a mouse model of prenatal PCB126 exposure. Female mice were bred and gavaged with 1 µmole/kg bodyweight PCB126 or vehicle control on embryonic days 0 and 14, and maternal and fetal tissues were collected on embryonic day 18.5. Total RNAs were isolated, and gene expression levels were analyzed in both maternal and fetal tissues using the NanoString nCounter system. Interestingly, we found that the expression levels of cytochrome P450 (Cyp)1a1 and Cyp1b1 were significantly increased in response to PCB exposure in the tested maternal and fetal tissues. Furthermore, PCB exposure altered the expression of several other genes related to energy balance, oxidative stress, and epigenetic regulation in a manner that was less consistent across tissue types. These results indicate that maternal PCB126 exposure significantly alters gene expression in both developing fetuses and pregnant dams, and such changes vary in intensity and expressivity depending on tissue type. The altered gene expression may provide insights into pathophysiological mechanisms by which in utero PCB exposures contribute to PCB-induced postnatal metabolic diseases.

Coptisine modulates the pharmacokinetics of florfenicol by targeting CYP1A2, CYP2C11 and CYP3A1 in the liver and P-gp in the jejunum of rats: a pilot study

Coptisine (COP) is the main active ingredient of Coptis chinensis. In Chinese veterinary clinics, Coptis chinensis is commonly used alongside florfenicol to treat intestinal infections. The goal of this study was to investigate the impact of COP co-administration on the pharmacokinetics of florfenicol in rats. Male Sprague-Dawley rats were orally administered COP (50 mg/kg BW) or sterile water for 7 consecutive days, followed by a single oral dose of florfenicol (25 mg/kg BW) on the 8th day. Pharmacokinetics of florfenicol were analysed using non-compartmental methods, while expression levels of cytochrome P450 (CYP) isoforms in the liver and P-glycoprotein (P-gp) in the jejunum were measured using real-time RT-PCR, Western blot and immunohistochemical analyses. Co-administration of COP and florfenicol significantly increased AUC(0-∞), MRT(0-∞), and Cmax of florfenicol, while CLz/F was significantly decreased. COP down-regulated the expression of CYP1A2, CYP2C11, and CYP3A1 in the liver, as well as P-gp in the jejunum. These findings suggest that co-administration of COP with florfenicol alters the pharmacokinetics of florfenicol in rats. The down-regulation of CYP and P-gp expression may contribute to this effect. Therefore, the co-administration of COP with florfenicol may enhance the prophylactic or therapeutic efficacy of florfenicol in veterinary practice.

Changes in the expression of drug-metabolising enzymes and drug transporters in mice with collagen antibody-induced arthritis

ABSTRACT We investigated the changes in the expression of drug-metabolising enzymes and drug transporters in the liver, small intestine and kidney of mice with collagen antibody-induced arthritis (CAIA) to determine whether changes in these expressions affect pharmacokinetics of drugs in patients with rheumatoid arthritis. mRNA expression levels of cytochrome P450 (Cyp) 2b10, Cyp2c29 and Cyp3a11 were observed to be lower in the liver and small intestine of CAIA mice than in control mice. Compared with control mice, mRNA expression levels of multidrug resistance 1b, peptide transporter 2 and organic anion transporter (Oat) 2 were high in the liver of CAIA mice. Changes in these expression levels were different among organs. However, elevated expression of Oat2 mRNA was not associated with an increase in protein expression and transport activity evaluated using [3H]cGMP as a substrate. These results suggest that arthritis can change the expression of pharmacokinetics-related genes, but the changes may not necessarily be linked to the pharmacokinetics in patients with rheumatoid arthritis. On the other hand, we found Oat2 mRNA expression level was positively correlated with plasma interleukin-6 level, indicating that transcriptional activation of Oat2 may occur in inflammatory state.

Combined Treatment with Herbal Medicine and Drug Ameliorates Inflammation and Metabolic Abnormalities in the Liver of an Amyotrophic Lateral Sclerosis Mouse Model.

To date, no effective drugs exist for amyotrophic lateral sclerosis (ALS), although riluzole (RZ) and edaravone have been approved for treatment. We previously reported that Bojungikgi-tang (BJIGT) improved motor activity through anti-inflammatory effects in the muscle and spinal cord of hSOD1G93A mice. Therefore, whether combined treatment with BJIGT and RZ synergistically affects liver function in hSOD1G93A mice was investigated. Two-month-old male hSOD1G93A mice were treated with BJIGT (1 mg/g) and RZ (8 μg/g) administered orally for 5 weeks. Drug metabolism and liver function tests of serum and liver homogenates were conducted. mRNA expression levels of cytochrome P450 (CYP) isozymes, inflammatory cytokines, metabolic factors, and mitochondrial oxidative phosphorylation (OXPHOS) subunits were examined using qPCR and Western blotting. Combined administration of BJIGT and RZ did not alter mRNA expression levels of drug-metabolism-related isozymes (CYP1A2 and CYP3A4) but significantly decreased the activity of liver-function-related enzymes (AST, ALT, ALP, and LDH). Increased expression of inflammatory cytokines (IL-1β, TNF-α, and IL-6) and of intracellular stress-related proteins (Bax, AMPKα, JNK, and p38) was reduced by the combined treatment in hSOD1G93A mice compared to that in control mice. Combined administration reduced the mRNA expression of metabolism-related factors and the expression of OXPHOS subunits. Elevated ATP levels and mitochondrial-fusion-associated protein were decreased after co-administration. Co-administration of BJIGT and RZ did not cause liver damage or toxicity but rather restored liver function in hSOD1G93A mice. This suggests that this combination can be considered a candidate therapeutic agent for ALS.

Level of Pyrethroid-Resistance Associated with Cytochrome P450 Expression in German Cockroach Blattella germanica (Blattodea: Ectobiidae) in the Field Collected Strains.

Background:Cytochrome P450-dependent monooxygenases are a very important metabolic system involve in insecticide resistance. This study was conducted to find the association between the expression level of cytochrome P450 (CYP450) and permethrin-resistance level among four strains of the German cockroach Blattella germanica (L) (Blattodea: Ectobiidae).Methods:Three field strains of German cockroach with different frequency of exposure to pesticides, and a laboratory susceptible strain were used in the present study. Insecticide susceptibility bioassays were carried out to detect resistance to permethrin. The concentration of CYP450 in each strain was determined using ion-exchange HPLC chromatography. Biochemical assays was performed to analyse CYP450 activities.Results:The resistance ratios (RR) to permethrin among three field strains were 3.29, 4.10 and 6.17-fold comping with the susceptible stain. The CYP450 activity of three field strains was 1.6, 2.4 and 2.7 times higher than in the susceptible stain. The amount of CYP450 per mg of protein was significantly different between the susceptible and the three resistant strains. The resistant cockroaches showed a relatively high expression of CYP450 enzymes. A strong correlation was found between permethrin resistance level and total concentration of CYP450 enzymes.Conclusion:The results of current study show that more frequent usage of a pyrethroid insecticide cause the metabolic insecticide resistance to rise in German cockroach. Therefore, there is a ratio correlation between resistance level and monooxygenases activities in insect. Thus, the control program must be managed according to history of pesticide usage.

Impact of ethylene glycol on DHEA dihydroxylation in Colletotrichum lini: Increasing the expression of cytochrome P450 and 6-phosphogluconate dehydrogenase and enhancing the generation of NADPH

3β,7α,15α-trihydroxy-5-androsten-17-one (7α,15α-diOH-DHEA), a key precursor of the novel oral contraceptive “Yasmin”, can be obtained by dihydroxylation in the 7α and 15α positions of dehydroepiandrosterone (DHEA) by Colletotrichum lini CGMCC 6051. However, the commercial-scale application of 7α,15α-diOH-DHEA is limited by the poor dihydroxylation efficiency and its low yield. This research investigated different organic solvents to improve the dihydroxylation efficiency of DHEA by C. lini CGMCC 6051. Results showed that ethylene glycol was the optimum organic solvent. With the addition of 0.5 % (v/v) ethylene glycol, the molar yield of 7α,15α-diOH-DHEA increased from 26.0%–79.4% at 12 g/L DHEA, and that of the intermediate product 7α−OH-DHEA decreased to 10.5 %. We then investigated the related functional mechanism of ethylene glycol on DHEA bioconversion. Results of two-dimensional electrophoresis proteomics analysis demonstrated that the expression levels of cytochrome P450 and 6-phosphogluconate dehydrogenase were increased upon the addition of ethylene glycol. Further studies suggested that ethylene glycol played critical roles in stabilizing the pH of the transformation system and generating co-enzyme NADPH during DHEA bioconversion. Hence, the addition of ethylene glycol induced the expression level of the key hydroxylase cytochrome P450 and increased the concentration of NADPH, which aided the dihydroxylation of DHEA in C. lini CGMCC6051.

Otoprotective Effects of Zingerone on Cisplatin-Induced Ototoxicity.

Previous studies have described the effects of zingerone (ZO) on cisplatin (CXP)-induced injury to the kidneys, liver, and other organs but not to the cochlea. This study aimed to investigate the effects of ZO on CXP-induced ototoxicity. Eight-week-old Sprague–Dawley rats were used and divided into a control group, a CXP group, and a CXP + ZO group. Rats in the CXP group received 5 mg/kg/day CXP intraperitoneally for five days. Rats in the CXP + ZO group received 5 mg/kg/day CXP intraperitoneally for five days and 50 mg/kg/day ZO intraperitoneally for seven days. Auditory brainstem response thresholds (ABRTs) were measured before (day 0) and after (day 10) drug administration. Cochlear histology was examined using hematoxylin and eosin (H&E) staining and cochlear whole mounts. The expression levels of cytochrome P450 (CYP)1A1, CYP1B1, inducible nitric oxide synthase (iNOS), nuclear factor kappa B (NFκB), tumor necrosis factor alpha (TNFα), and interleukin 6 (IL6) were estimated using quantitative reverse transcription-polymerase chain reaction. The expression levels of heme oxygenase 1 (HO1) and caspase 3 were analyzed via Western blotting. The auditory thresholds at 4, 8, and 16 kHz were attenuated in the CXP + ZO group compared with the CXP group. The mRNA expression levels of CYP1A1, CYP1B1, iNOS, NFκB, TNFα, and IL6 were lower in the CXP + ZO group than in the CXP group. The protein expression levels of HO1 and caspase 3 were lower in the CXP + ZO group than in the CXP group. Cotreatment with ZO exerted otoprotective effects against CXP-induced cochlear injury via antioxidative and anti-inflammatory activities involving CYPs, iNOS, NFκB, and TNFα.

Synthesis, structural, cytotoxic and pharmacokinetic evaluation of some thiosemicarbazone derivatives.

Iron(III) and nickel(II) complexes bearing a thiosemicarbazone framework were synthesized by a one-pot synthesismethod. The structures were characterized by elemental analysis, IR, 1 H NMR, APCI Mass, conductivity, magnetic moment measurements. Molecular and crystal structures of the iron(III) complex were obtained from single-crystal X-ray diffraction. The findings showed that the metal atom adopts a slightly distorted square-pyramidal coordination, with the four donor atoms of the thiosemicarbazone ligand defining the basal plane and a chloride atom occupying the apical position. In the crystal lattice, the structure is stabilized by intermolecular O─H···O and C─H···O interactions. The cytotoxic activity was studiedby MTT assay, the expression levels of cytochrome P450 (CYP) enzymes by Western blot, and the lipophilicity (LogP) by using the shake-flask method, another pharmacokinetic parameter. The findings showed that the IC50 values decreased with the decrease of the LogP values of the substances. Cytochrome P450 expression levels were found specific for each compound and each cell line. As a result, the pharmacokinetic properties of the newly synthesized thiosemicarbazone compounds are crucial for oral administration and provideus with cluesfor prospective in vivo studies.

Effects of baicalin on pharmacokinetics of florfenicol and mRNA expression of CYP1A2, CYP2C11, CYP3A1, UGT1A1, MDR1, and ABCC2 in rats

Background: The traditional Chinese medicine Scutellariae radix is often used in combination with antibiotics, such as florfenicol, in Chinese veterinary medicine. Baicalin (5, 6, 7-trihydroxyflavone-7-β-D-glucuronide) is the main active constituent of S. radix. The effects of baicalin on the pharmacokinetics of florfenicol are not known. Thus, we have studied the effects of baicalin on florfenicol pharmacokinetics and the mRNA expression of drug-metabolizing enzymes/efflux transporters in rats. Materials and Methods: Sprague-Dawley rats were given baicalin (50 mg/kg BW or 100 mg/kg BW) or 0.9% sodium chloride solution by intragastric administration for 7 days. They were then fed florfenicol by intragastric administration (25 mg/kg BW) on the 8th day. Blood samples were collected at various times, and the plasma concentrations of florfenicol were estimated with ultra-high performance liquid chromatography. The mRNA expression levels of cytochrome P450 (CYP) CYP1A2, CYP2C11, CYP3A1, UDP-glucuronosyltransferase 1A (UGT1A), multidrug resistance 1, and ATP-binding cassette C2 (ABCC2) in the liver and jejunum were analyzed with a real-time polymerase chain reaction. Results: The area under the concentration-time curve from zero to infinity, mean residence time from zero to infinity, elimination half-life, and peak concentration of florfenicol were significantly increased and the apparent volume of distribution fraction of the dose absorbed and plasma clearance fraction of the dose absorbed were significantly decreased by baicalin; the mRNA expression levels of CYP1A2, CYP2C11, CYP3A1, UGT1A1, and ABCC2 were down-regulated by baicalin. Conclusion: Baicalin affected the pharmacokinetics of florfenicol in rats, increased the plasma concentration and residence time of florfenicol, probably by decreasing the mRNA expression levels of CYP1A2, CYP2C11, CYP3A1, UGT1A1, and ABCC2 in the liver and jejunum.

Curcumin Ameliorates Benzo[a]pyrene-Induced DNA Damages in Stomach Tissues of Sprague-Dawley Rats.

Benzo[a]pyrene (BaP) is a well-known carcinogen formed during the cooking process. Although BaP exposure has been implicated as one of the risk factors for lung cancer in animals and humans, there are only limited data on BaP-induced gastrointestinal cancer. Therefore, this study investigated the protective effects of curcumin on BaP-induced DNA damage in rat stomach tissues. BaP (20 mg/kg/day) and curcumin (50, 100, or 200 mg/kg) were administered daily to Sprague-Dawley rats by oral gavage over 30 days. Curcumin was pre-administered before BaP exposure. All rats were euthanized, and liver, kidney, and stomach tissues were removed at 24 h after the last treatment. We observed that aspartate aminotransferase (AST), alanine aminotransferase (ALT), and glucose levels were significantly reduced in rats treated with high dose co-administration of curcumin (200 mg/kg) compared to BaP alone. The expression levels of cytochrome P450 (CYP) 1A1 and CYP1B1 were significantly increased in the liver of rats treated with BaP. However, co-administration of curcumin (200 mg/kg) with BaP markedly reduced CYP1A1 expression in a dose-dependent manner. Furthermore, plasma levels of BaP-diolepoxide (BPDE) and BaP metabolites were significantly reduced by co-administration of curcumin (200 mg/kg). Additionally, co-administration of curcumin (200 mg/kg) with BaP significantly reduced the formation of BPDE-I-DNA and 8-hydroxydeoxy guanosine (8-OHdG) adducts in the liver, kidney, and stomach tissues. The inhibition of these adduct formations were more prominent in the stomach tissues than in the liver. Overall, our observations suggest that curcumin might inhibit BaP-induced gastrointestinal tumorigenesis and shows promise as a chemopreventive agent.

De novo assembly of the transcriptome for Greenbug (Schizaphis graminum Rondani) and analysis on insecticide resistance‐related genes

AbstractThe greenbug, Schizaphis graminum Rondani is a major pest species of wheat crops. In this study, a transcriptome sequencing, and the expression of the 12 genes related to insecticide resistance were conducted in S. graminum. The sequencing and subsequent bioinformatics analysis outputed 46,593 unigenes, among which 28,289 unigenes were annotated to corresponding functions by blasting with high homologous genes in database, giving annotation rate of 60.72%. To gain insight into the mechanism of insecticide resistance, the expression of the 12 genes related to insecticide resistance for S. graminum was investigated. The expression level of aminopeptidase N (AN), cytochrome P450 (CYP), acetylcholinesterase 1 (AC), catalase (CAT), cytochrome c oxidas (CCC), GABA receptor (GABA), glutathione S‐transferase (GST) were highest in the apterous nymphs among different developmental stages; The expression level of AN, CBL, CYP, CA, SD, and GST were relatively more abundant in the abdomen compared to head and throax. The results could give out the key information about the relationship between the expression of these genes in different developmental stages, tissues, treatments and metabolism of insecticides. These genes that were co‐up‐regulated significantly in third instar nymphs of S. graminum induced by imidacloprid, were consistent with their putative involvement in insecticide resistance. This provides most comprehensive transcriptome data for S. graminum to further study and managenment.

Cross-resistance and biochemical characterization of buprofezin resistance in the white-backed planthopper, Sogatella furcifera (Horvath)

Buprofezin is a chitin synthesis inhibitor that is very effective against Homopteran pests, such as the white-backed planthopper (WBPH), S. furcifera (Horvath). In the present study, resistance selection, cross-resistance and mechanisms of buprofezin resistance were investigated in this planthopper species. However, the mechanism associated with resistance to growth regulator insecticides (IGRs) remains largely unknown. A resistant strain (Bup-R) with a resistance level (22-fold) to buprofezin was developed through continuous selection for 47 generations from a laboratory susceptible strain (Bup-S). The results showed that the Bup-R exhibited no cross-resistance to other tested insecticides. Synergism tests showed that piperonyl butoxide (PBO) (SR = 3.9-fold) and diethyl maleate (DEM) (SR = 1.8-fold) had synergistic effects on buprofezin toxicity in the resistant strain (F47). Enzyme activity results revealed an approximate 5.7-fold difference in cytochrome P450 monooxygenase and a 2-fold difference in glutathione S-transferase (GST) between the resistant and susceptible strains, suggesting that the increased activity of these two enzymes is likely the main detoxification mechanism involved in resistance to buprofezin in this species. Furthermore, the mRNA expression levels of cytochrome P450 (CYP) and GST genes by quantitative real-time PCR results indicated that sixteen P450 and one GST gene were significantly overexpressed in the Bup-R strain, among which thirteen P450 genes and one GST gene were >2-fold higher than in the Bup-S strain. The present study increases our knowledge of the buprofezin resistance mechanism in S. furcifera and provides a useful reference for integrated pest management (IPM) strategies.

Characterization of nitenpyram resistance in Nilaparvata lugens (Stål)

Nitenpyram is very effective in controlling Nilaparvata lugens (brown planthopper, BPH), and its resistance has been reported in field populations; however, the resistance mechanism remains unclear. In the present study, cross-resistance and resistance mechanisms in nitenpyram-resistant BPH were investigated. A resistant strain (NR) with a high resistance level (164.18-fold) to nitenpyram was evolved through successive selection for 42 generations from a laboratory susceptible strain (NS). The bioassay results showed that the NR exhibited cross-resistance to imidacloprid (37.46-fold), thiamethoxam (71.66-fold), clothianidin (149.17-fold), dinotefuran (98.13-fold), sulfoxaflor (47.24-fold), cycloxaprid (9.33-fold), etofenprox (10.51-fold) and isoprocarb (9.97-fold) but not to triflumezopyrim, chlorpyrifos and buprofezin. The NR showed a 3.21-fold increase in cytochrome P450 monooxygenase (P450) activity compared to that in the NS, while resistance was also synergized (4.03-fold) with the inhibitor piperonyl butoxide (PBO), suggesting a role of P450. Furthermore, the mRNA expression levels of cytochrome P450 (CYP) genes by quantitative real-time PCR results indicated that twelve P450 genes were significantly overexpressed in the NR strain, especially CYP6ER1 (203.22-fold). RNA interference (RNAi) suppression of CYP6ER1 through injection of dsCYP6ER1 led to significant susceptibility in the NR strain. The current study expands our understanding of the nitenpyram resistance mechanism in N. lugens, provides an important reference for integrated pest management (IPM), and enriches the theoretical system of insect toxicology.

Comparative expression of two detoxification genes by Callosobruchus maculatus in response to dichlorvos and Lippia adoensis essential oil treatments

The cowpea beetle, Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae), is a field-to-store pest, which can cause up to 80% damage of cowpea grains within 3 months of storage. The control approach consisting of application of synthetic pesticides has become challenging following the increased resistance and toxicity to non-target organisms and the environment. Here, we hypothesized that Lippia adoensis essential oil (EO) (plant-based insecticide) can repress cytochrome P450-dependent mono-oxygenase and glutathione-S-transferase (GST) genes and suppress C. maculatus resistance to dichlorvos (O,O-dimethyl-O-2,2-dichlorovinylphosphate or DDVP). The methods consisted of separately exposing C. maculatus adults to cowpea seeds treated with DDVP and L. adoensis EO. Their physiological and molecular responses were monitored for five generations. Adult mortality of DDVP-treated beetles significantly decreased across generations and negatively correlated with the reproduction parameters (increase in fecundity and adult emergence) and seed damage. Similarly, the decrease in adult susceptibility corresponded with the increase in the expression levels of cytochrome P450 and GST genes (overexpression of genes). However, the adult susceptibility to EO treatments remained consistent across generations and correlated with the down-regulation of targeted genes from the third generation (F3). These results support our hypotheses and provide a probable molecular basis of resistance to DDVP and susceptibility to L. adoensis EO in C. maculatus. Therefore, L. adoensis EO represents an alternative insecticide that could be employed to enhance the vulnerability of this pest.

Generation of Human iPSC–Derived Intestinal Epithelial Cell Monolayers by CDX2 Transduction

Background & aimsTo develop an effective and safe orally administered drug, it is important to predict its intestinal absorption rate, intestinal first-pass effect, and drug-drug interactions of orally administered drugs. However, there is no existing model to comprehensively predict the intestinal pharmacokinetics and drug-response of orally administered drugs. In this study, we attempted to generate homogenous and functional intestinal epithelial cells from human induced pluripotent stem (iPS) cells for pharmaceutical research.MethodsWe generated almost-homogenous Villin- and zonula occludens-1 (ZO1)-positive intestinal epithelial cells by caudal-related homeobox transcription factor 2 (CDX2) transduction into human iPS cell-derived intestinal progenitor cells.ResultsThe drug absorption rates in human iPS cell-derived intestinal epithelial cell monolayers (iPS-IECM) were highly correlated with those in humans (R2=0.91). The expression levels of cytochrome P450 (CYP) 3A4, a dominant drug-metabolizing enzyme in the small intestine, in human iPS-IECM were similar to those in human small intestine in vivo. In addition, intestinal availability in human iPS-IECM (the fraction passing the gut wall: Fg=0.73) was more similar to that in the human small intestine in vivo (Fg=0.57) than to that in Caco-2 cells (Fg=0.99), a human colorectal adenocarcinoma cell line. Moreover, the drug-drug interaction and drug-food interaction could be observed by using our human iPS-IECM in the presence of an inducer and inhibitor of CYP3A4, i.e., rifampicin and grape fruit juice, respectively.ConclusionTaking these results together, we succeeded in generating the human iPS-IECM that can be applied to various intestinal pharmacokinetics and drug-response tests of orally administered drugs.