• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Transformation of berberine to its demethylated metabolites by the CYP51 enzyme in the gut microbiota

    2021-11-11 13:37:54ZhengWeiZhangLinCongRanPengPeiHanShuRongMaLiBinPanJieFuHangYuYanWangJianDongJiang
    Journal of Pharmaceutical Analysis 2021年5期

    Zheng-Wei Zhang , Lin Cong , Ran Peng, Pei Han, Shu-Rong Ma, Li-Bin Pan, Jie Fu,Hang Yu, Yan Wang, Jian-Dong Jiang

    State Key Laboratory of Bioactive Substance and Function of Natural Medicines,Institute of Materia Medica,Chinese Academy of Medical Sciences&Peking Union Medical College, Beijing,100050, China

    Keywords:Berberine Biotransformation Gut microbiota CYP51 Demethylated metabolite

    ABSTRACT Berberine (BBR) is an isoquinoline alkaloid extracted from Coptis chinensis that improves diabetes,hyperlipidemia and inflammation. Due to the low oral bioavailability of BBR, its mechanism of action is closely related to the gut microbiota. This study focused on the CYP51 enzyme of intestinal bacteria to elucidate a new mechanism of BBR transformation by demethylation in the gut microbiota through multiple analytical techniques. First, the docking of BBR and CYP51 was performed; then, the pharmacokinetics of BBR was determined in ICR mice in vivo,and the metabolism of BBR in the liver,kidney,gut microbiota and single bacterial strains was examined in vitro.Moreover,16S rRNA analysis of ICR mouse feces indicated the relationship between BBR and the gut microbiota. Finally, recombinant E. coli containing cyp51 gene was constructed and the CYP51 enzyme lysate was induced to express.The metabolic characteristics of BBR were analyzed in the CYP51 enzyme lysate system.The results showed that CYP51 in the gut microbiota could bind stably with BBR,and the addition of voriconazole(a specific inhibitor of CYP51) slowed down the metabolism of BBR, which prevented the production of the demethylated metabolites thalifendine and berberrubine. This study demonstrated that CYP51 promoted the demethylation of BBR and enhanced its intestinal absorption, providing a new method for studying the metabolic transformation mechanism of isoquinoline alkaloids in vivo.

    1. Introduction

    The human intestine is the natural host of many microorganisms [1], and the gut microbiota is a complex group containing hundreds of times more genes than the human genome [2].Referred to as a“hidden organ”of the body[3],the gut microbiota has been reported to be associated with many diseases, including obesity [4], functional bowel disease, colitis [5-8] and cardiovascular disease [9]. There are many metabolic enzymes in the gut microbiota,such as β-glucuronidase,β-glucosidase, nitroreductase and azoreductase [10,11]. These enzymes can interact with oral drugs and produce metabolites that are different from those produced by organs [12]. Therefore, the gut microbiota has good biotransformation ability and can participate in the metabolism of oral natural products in vivo. In addition, studies have shown that regulation of the composition of gut microbiota can contribute to disease treatment [13-15].

    Sterol 14α-demethylase (P45014DM, CYP51) is a key biosynthetic enzyme [16] belonging to the cytochrome P450 family of enzymes, which catalyze the 14α-methyl hydroxylation of sterol precursors [17,18]. More than 100 CYP51 sequences have been found in 82 species, some of which contain multiplecyp51genes.Meanwhile, as the P450 enzyme in bacteria, fungi, lower eukaryotes,higher plants and mammals,CYP51 catalyzes the metabolism of xenobiotics through demethylation.It has been found that CYP51 has five kinds of substrates, including lanosterol, 24,25-dihydrolanosterol, 24-methylene-24,25-dihydrolanosterol, obtusifoliol, and 4β-desmethyllanosterol [19]. These substrates can be demethylated by CYP51. For example, lanosterol can be metabolized by CYP51 to 14-demethyl-14-dehydrolanosterol (FF-MAS). In addition, studies have shown that one of the main metabolic pathways of isoquinoline alkaloids is demethylation,which may be closely related to CYP51, as shown by docking simulation [20].

    Berberine(BBR),a quaternary ammonium alkaloid isolated from the traditional Chinese medicine Coptis chinensis,is present in six plant families (Oleaceae, Papaveraceae, Ranunculaceae, Rutaceae,Menispermaceae, and Rhamnaceae) that were originally used as antipyretic,antidote and antibacterial drugs in clinical practice[21].In recent years,studies have shown BBR to be a new lipid-lowering drug, acting by lowering cholesterol, triglyceride and low-density lipoprotein levels, which is different from the mechanism of action of statins[22].Studies have demonstrated that rats exhibit 16 metabolites in their bile,urine and feces after oral administration of BBR [23] (Fig.1A), most of which are related to the demethylation process.

    Therefore,the main metabolic process of BBR in vivo called the demethylation reaction was studied.This study would demonstrate that CYP51 promotes the demethylation of BBR and provides a new method for studying the metabolic transformation mechanism of isoquinoline alkaloids in vivo.

    2. Experimental

    2.1. Materials and reagents

    BBR was obtained from J&K Scientific Ltd. (Beijing, China).Rotundine (internal standard-1, IS-1) was purchased from the Institute for Food and Drug Control (Beijing, China). Benzylamine(IS-2) was purchased from J&K Scientific, Ltd. (Beijing, China).Thalifendine (M1) was purchased from Shanghai Hekang Biotechnology Co., Ltd. (Shanghai, China). Berberrubine (M2) was purchased from Chengdu Herbipurify Co., Ltd. (Chengdu, China).Voriconazole was purchased from Beijing Solarbio Science &Technology Co., Ltd. (Beijing, China). Lanosterol was purchased from Chengdu Pufei De Biotech Co., Ltd. (Chengdu, China).Enterobacter cloacae,Enterococcus faecium,Staphylococcus epidermidis,Enterococcus faecalis,Pseudomonas aeruginosa,Acinetobacterbaumannii,Staphylococcus aureus,Escherichia coli,Klebsiella pneumoniae,Proteus mirabilis,Bifidobacterium longum,Bifidobacterium breve,Lactobacillus acidophilus, andLactobacillus caseiwere purchased from Nanjing Lezhen Biotechnology Co., Ltd. (Nanjing,China). The sterol 14α-demethylase ELISA Kit was purchased from Nanjing Jin Yibai Biological Technology Co., Ltd. (Nanjing, China).

    2.2. Animals

    ICR mice (male,19-21 g) were obtained from SiPeiFu Biotechnology Co.,Ltd.(Beijing,China)with the license No.SCXK(Beijing)2016-0002,and the experimental conditions were as follows:12 h light/dark cycle, 8 a.m. to 8 p.m.; ambient temperature 20-25°C;and relative humidity 40%-70%. All animals were fasted for 12 h before starting the experiment. Animal experiments were approved by the Animal Medicine and Experimental Committee of the Chinese Academy of Medical Sciences and Peking Union Medical College, China in accordance with institutional guidelines and ethical guidelines.

    2.3. Instruments

    The following instruments were used: LC-MS/MS-8050 (Shimadzu Corporation, Kyoto, Japan), LC-MS/MS-8060 (Shimadzu Corporation,Kyoto,Japan)and LC-MS solution workstation for online analysis of metabolites (Shimadzu Corporation, Kyoto, Japan);FSH-2 adjustable high-speed homogenizer (Jitan Shenglan Instrument Manufacturing Co., Ltd., Jitan, China); Heraeus Pico21 microcentrifuge (Thermo Fisher Scientific, Dreieich, Germany);MD200-2 nitrogen-blowing instrument (Hangzhou Diansheng Instrument Co., Ltd., Hangzhou, China); ThermoMixer (Eppendorf,Hamburg, Germany); Spectra Max Model 190 microplate reader(Molecular Devices, Silicon Valley, CA, USA).

    BBR and its metabolites from each sample in vitro/in vivo and enzymatic reaction studies were analyzed by using a Shimpack XR0ODS II column(75 mm×3 mm,2.3 μm,Shimadzu Corporation,Kyoto, Japan) at a column temperature of 40°C. The mobile phase consisted of water-formic acid (0.5%,V/V) and acetonitrile with a gradient elution (0 min, 90:10; 3.5 min, 75:25; 5.0 min, 70:30;5.01 min, 80:20; 6.0 min,90:10); the flow rate was 0.4 mL/min.

    Lanosterol and 14-demethyl-14-dehydrolanosterol (FF-MAS)from each sample in the enzymatic reaction study were analyzed by using Alltima TM C18column (4.6 mm × 150 mm, 5 μm) at a column temperature of 40°C.The mobile phase consisted of waterammonia (0.5%,V/V) and acetonitrile, with a gradient elution(0.01 min, 70:30; 2 min, 95:5; 7.0 min, 95:5; 7.01 min, 70:30;10.0 min, stop); the flow rate was 0.4 mL/min. The ESI+ mode analysis was used, and the specific parameters were as follows:nebulizer gas flow rate, 3.0 L/min; dry gas flow rate, 10.0 L/mL;interface voltage,-4.5 kV;collision-induced dissociation pressure,230 kPa; desolvation line temperature, 250°C; and heating block temperature, 400°C. Multiple reaction monitoring modes were used to quantify the sample. Them/ztransitions werem/z335.70 →320.10 for BBR,m/z355.70 →191.90 for IS-1,m/z321.65 → 307.15 for M1,m/z321.65 → 307.15 for M2,m/z409.15 →353.30 for lanosterol,m/z393.20 →151.10 for FF-MAS,andm/z108.20 →91.10 for IS-2.

    2.4. Method of molecular docking

    The interaction between BBR and CYP51 was simulated using Discovery Studio software (v16.1.0.15350). The crystal structure of CYP51 was obtained from the Protein Database (PDB) with PDB ID 2W09.

    The BBR structure was constructed using ChemDraw15.0, and the structure of the target compound was subjected to energy minimization by the minimization module in Discovery Studio Client software (v16.1.0.15350) to obtain an optimized structure.The CDOCKER method was selected to simulate the interaction between the target compound and the protein after optimization.The pose cluster radius parameter was set to 0.5,and the rest of the parameters were set to default values.

    2.5. Analytical methods of BBR pharmacokinetics in vivo

    Animals were divided into BBR group and voriconazole group,and the ICR mice were given 200 mg/kg BBR and 200 mg/kg BBR +30 mg/kg voriconazole in single oral administrations. After administration for 0.17,0.33,0.5,1,1.5,2,3,4,6,12,and 24 h,blood was taken from the retrobulbar venous plexus and transferred to a sample tube to which heparin had been added. Samples were stored at -20°C prior to analysis. After 3 h of administration, the mice were free to eat. All animal programs were approved by the Animal Care Welfare Committee of the Institute of Materia Medica,Chinese Academy of Medical Sciences and Peking Union Medical College (Beijing, China). In addition, all animal experiments were conducted in strict accordance with the Laboratory Animal Care and Use Guidelines issued by the Animal Protection and Welfare Institute.

    The plasma (100 μL) was added to 300 μL of methanol (containing 50 ng/mL IS)to precipitate the protein.After vortexing,the tubes were centrifuged at 10,800 rpm for 10 min, the supernatant was extracted, and 2 μL was injected. The concentrations used for the standard curve were as follows: 1, 2,10,100, and 1000 ng/mL.

    The two-compartment model was used to simulate pharmacokinetic parameters, and the data were analyzed by using DAS 3.0.

    2.6. Preparation of intestinal bacterial incubation in vitro

    An anaerobic medium for intestinal bacteria was prepared according to literature reports [11]. The obtained medium was autoclaved at 0.1 MPa and 121°C for 20 min and used after being cooled.

    Intestinal bacterial cultures were prepared according to literature reports[24].After being anesthetized,the mice were sacrificed by cervical dislocation. The abdomen was incised, the colon was removed, and the colon contents were homogenized in an anaerobic chamber.After mixing 1 g of the contents in 20 mL of anaerobic medium, the cultures were incubated at 37°C for 60 min under anaerobic conditions (N2environment) and set aside.

    The samples were divided into five groups: negative control group; the 10, 50, and 100 mg/mL BBR groups; and the 50 mg/mL BBR + 3.5 μg/mL voriconazole group. BBR and voriconazole were dissolved in methanol;BBR was formulated at concentrations of 10,50, and 100 mg/mL; and voriconazole was formulated at a concentration of 3.5 μg/mL. Then, 10 μL of the sample solution was added to each sample tube,1 mL of the intestinal culture medium was added in an anaerobic chamber, and the sample tubes were sealed with sealing films and incubated at 37°C for 12, 24,36, 48,60,and 72 h while using methanol as a negative control.When the incubation was completed, the samples were removed, added to 1 mL of methanol,vortexed for 30 s and centrifuged at 14,800 rpm for 15 min. The supernatant was diluted in groups as follows: 10 times for the 10 mg/mL BBR group;50 times for the 50 mg/mL BBR group; 100 times for the 100 mg/mL BBR group, and 50 times for the 50 mg/mL BBR+3.5 μg/mL voriconazole group.After dilution,100 μL of each sample was added to 300 μL of methanol(containing 50 ng/mL IS), vortexed and centrifuged at 14,800 rpm for 10 min.The supernatant was extracted, and 2 μL was injected. The concentrations used for the standard curve were as follows: 1, 2, 10,100, and 1000 ng/mL.

    2.7. Preparation of liver and kidney homogenates for BBR metabolism in vitro

    The mice were sacrificed by cervical dislocation, and the abdomen was incised to remove the liver and kidneys.With a ratio of 1 g of organ to 5 mL of physiological saline, the samples were homogenized for use.

    Liver and kidney homogenates were divided into two groups:BBR group (50 mg/mL) and voriconazole (3.5 μg/mL) group. BBR was formulated to a concentration of 50 mg/mL, and voriconazole was formulated to a concentration of 3.5 μg/mL.Then,10 μL of the sample solution was added to each sample tube, and 1 mL of the organ homogenate was added and incubated at 37°C for 0,15,30,60, 90, and 120 min. When the incubation was completed, the samples were removed, treated with 1 mL of methanol, vortexed for 30 s and centrifuged at 14,800 rpm for 15 min.Then,100 μL of the supernatant of each sample was added to 300 μL of methanol(containing 50 ng/mL IS).Subsequently,the samples were vortexed and centrifuged at 14,800 rpm for 10 min. The supernatant was extracted, and 2 μL was injected. The concentrations used for the standard curve were as follows: 1, 2,10,100, and 1000 ng/mL.

    2.8. Preparation of liver and kidney microsomal for BBR metabolism in vitro

    The mice were sacrificed by cervical dislocation, and the liver and kidneys were removed into beakers containing physiological saline at 4°C. Then, the organs were washed until no blood remained; filter paper was used to blot the remaining liquid; the excess tissues were removed and weighed; Tris-KCl was added at 2 mL/g according to the weight of the organ so that the mixture was homogenized. Then, the homogenate was centrifuged at 10,000gand 4°C for 25 min to extract the supernatant.After the addition of Tris solution,sample centrifugation was continued at 105,000gand 4°C for 1 h. Then, the supernatant was discarded, and the precipitate was resuspended with an appropriate amount of Tris-KCl and centrifuged at 105,000gand 4°C for 1 h. Finally, the supernatant was discarded again, 8 mL of Tris-KCl was added and the sample was suspended to obtain the prepared liver and kidney microsomes.

    Liver and kidney microsomes were divided into two groups:BBR group (50 mg/mL) and voriconazole group (50 mg/mL BBR + 3.5 μg/mL voriconazole). BBR was formulated to a concentration of 50 mg/mL, voriconazole was formulated to a concentration of 3.5 μg/mL and the NADPH generation system was formulated as follows:1.3 mmol/L NADP,3.3 mmol/L G-6-P,0.4 U/mL G-6-PD,and 3.3 mmol/L MgCl2.The prepared mouse liver and kidney microsomes were diluted with 4°C Tris buffer (pH 7.4)until the protein concentration was 0.5 mg/mL. After incubation for 3 min at 37°C in advance,10 μL of sample solution and NADPH solution were added and incubated at 37°C for 0,15, 30, 60, 90,and 120 min.Then,100 μL of the supernatant of each sample was added to 300 μL of methanol (containing 50 ng/mL IS). Subsequently,the samples were vortexed and centrifuged at 14,800 rpm for 10 min.The supernatant was extracted,and 2 μL was injected.The concentration of the standard curve was as follows: 1, 2,10,100, and 1000 ng/mL.

    2.9. Preparation of standard bacterial strains for BBR metabolism in vitro

    The number of colonies of 14 standard bacterial strains on culture medium was counted by the plate method after resuscitating the cells.According to the results after counting,the culture media for the standard bacterial strains were diluted until the bacterial concentrations were the same.

    Then, 0.9 mL of sterilized anaerobic medium and 100 μL of the diluted 14 standard bacterial cultures were added to each sample tube in an anaerobic chamber. Then, each tube was blown with nitrogen and sealed. After incubation at 37°C for 1 h in advance,10 μL of BBR(50 mg/mL)was added to each sample,which was then incubated at 37°C for 24 h. Then, 1 mL of methanol (containing 50 ng/mL IS) was added to each sample, which was then vortexed and centrifuged at 14,800 rpm for 10 min. The supernatant was extracted, and 2 μL was injected. The concentrations used for the curve were as follows: 1, 2,10,100, 500, and 1000 ng/mL.

    Samples of each standard bacterial strain were divided into three groups after four single strains were screened: negative control group (methanol), BBR group (50 mg/mL BBR), and voriconazole group (50 mg/mL BBR + 3.5 μg/mL voriconazole). The four standard bacterial strains, namely,E. faecalis,S. epidermidis,E. cloacae, andE. faecium, were mixed with 50 mg/mL BBR and incubated to determine the concentration of BBR and the activity of CYP51 at 48 and 72 h.Then,the percentage of BBR metabolism was calculated.

    The 0.9 mL of sterilized anaerobic culture medium and 100 μL of the diluted single-culture medium were added to each sample in an anaerobic chamber. Then, each tube was blown with nitrogen,sealed, incubated at 37°C for 24 h and ultrasonically disrupted.Then,the activity of CYP51 was determined by the CYP51 ELISA Kit.

    2.10. 16S rRNA analysis of ICR mouse feces

    By using 16S V3-V4:340-805R specific primers, the V3-V4 region of 16S rRNA was targeted, and the 16S rRNA gene was amplified. The PCR products were mixed in equal proportions.Then,the PCR products were purified by the OMEGA Gel Extraction Kit. The sequencing library was constructed using the NEXTflex Rapid Illumina DNA-seq Kit, while the quality of the library was tested by using a Qube 2 fluorometer and an Agilent Bioanalyzer 2100. Finally, the library was sequenced on the HISEQ 2500 platform, and 250-bp paired-end reads were generated.

    Sequences were analyzed using Quantitative Insights Into Microbial Ecology(QIIME)software.First,the reads were classified by using the quality filters module of QIIME. Then, each operational taxonomic unit (OTU) was selected for a representative sequence,and the classification information for each representative sequence was annotated by using the Ribosomal Database Project classifier.Sequences with similarity >97% were assigned to the same OTU.

    2.11. Expression and functional verification of CYP51

    Thecyp51gene ofSaccharomyces cerevisiaeS288C(NC_022591.1) was synthesized by Sangon Biotech (Shanghai,China).Thecyp51gene was amplified using primer-F/primer-R.The primers for thecyp51gene were designed by Primer 5.0 as follows:cyp51-F: AGCAAATGGGTCGCGGATCCAGCGCGACCAAAAGCATCG;cyp51-R: TCGAGTGCGGCCGCAAGCTTGATTTTCTGTTCCGGGTTACGT.Thirty-five cycles of PCR were performed with Phanta polymerase(Vazyme Biotech Co.,Ltd.,Nanjing,China)in a 50-μL system.Then,1% agarose gel electrophoresis and gene sequencing were performed to verify the gene amplification. Thecyp51fragment was cloned between the HindIII/BamHI sites of the expression vector pET28a (New England Biolabs, Ipswich, MA, USA) using Gibson Assembly Master Mix(New England Biolabs,Ipswich,MA,USA)to obtain pET28a-cyp51.

    The plasmid pET28a-cyp51was introduced intoE.coliBL21 cells(Vazyme Biotech Co., Ltd., Nanjing, China). After verifying the sequence, clones were used to express the cyp51 protein(ONH80457.1).E.coliBL21 colonies with pET28a-cyp51were grownin 100 mL of Luria-Bertani broth containing 15 μg/mL kanamycin at 37°C. When the amplified bacterial solution reached an OD600of 0.6-0.8,isopropyl β-D-1-thiogalactopyranoside was added at a final concentration of 0.1 mM to induce expression, and the cells were grown at 16°C for 20 h.After centrifugation,the bacterial cells were suspended in 10 mL of phosphate buffered saline (PBS) solution,andE.coliBL21 with a pet28a plasmid lacking theCYP51gene was used as a control. Supernatants and pellets were prepared for SDS gel electrophoresis. After concentrating to 1 mL through a microporous membrane(MWCO:30,000),the concentrated solution was used for functional verification.

    The enzymatic reaction system was composed of PBS solution(1×) containing NADPH (0.5 mM), enzyme lysate(10 μL), and lanosterol(10 μg/mL),and incubated for 0,1,2,and 4 h.The products obtained after incubation were used to analyze lanosterol and FFMAS by LC-MS/MS. The enzymatic reaction system was composed of 1×PBS solution containing NADPH (0.5 mM), enzyme lysate(10 μL),and substrate BBR(10 μg/mL),and incubated for 0,1,2,and 4 h. The products obtained after incubation were used to analyze M1 and M2 by LC-MS/MS.

    2.12. Statistical analysis

    Statistical analysis was performed using ANOVA and Student'sttest in GraphPad Prism version 5 (GraphPad, San Diego, CA, USA).The data are expressed as mean ± standard deviation (SD), andPvalues less than 0.05 are considered statistically significant.

    3. Results and discussion

    3.1. Molecular docking between BBR and CYP51

    The putative chemical mechanism for the docking of BBR alkaloids by CYP51 (PDB ID: 2W09) is shown in Fig.1B. Based on the results of molecular docking, BBR can stably bind to CYP51 with a binding energy of-23.1 kcal/mol(Fig.1C).In addition,the form of action demonstrated that the BBR structure can form various bonds with CYP51 for tight binding to promote the demethylation effect of CYP51 (ring b of BBR formed π bonds with the alkyl group of Met79; ring d of BBR formed π bonds with the alkyl group of Ala256;ring e of BBR simultaneously formed π bonds with the alkyl group of Ala256 and the sulfhydryl group of Cys394;the oxygen in the 10th methoxy group of BBR formed hydrogen bonds with Val395).

    3.2. Pharmacokinetics of BBR in vivo

    According to the above results,it could be inferred that BBR was likely to produce demethylated metabolites by CYP51-mediated metabolism. Therefore, a BBR metabolism experiment was conducted in ICR mice,and the BBR metabolic mechanism in vivo was explored.As shown in Table 1,the AUC(0-24h)increased by 9.8%,t1/2increased by 17.4%, andCmaxincreased by 45.7% after addition of voriconazole (Fig. 1E) compared with the values after oral administration of 200 mg/kg BRR alone (Fig.1D). Moreover, there were double peaks in the drug-time curve. It was speculated that this might be attributed to enterohepatic circulation after oral administration.

    Table 1 The pharmacokinetic parameters of ICR mice after oral administration of berberine(BBR) simulated by a two-compartment model.

    Fig.2.Metabolism of BBR by the mice gut microbiota in vitro.(A)Percentage of residual BBR(10,50,and 100 mg/mL)after intestinal metabolism in mice in vitro.(B)Level of M1 produced from BBR(10,50,and 100 mg/mL)after intestinal metabolism in mice in vitro.(C)Level of M2 produced from BBR(10,50,and 100 mg/mL)after intestinal metabolism in mice in vitro.(D)Comparison of the percentage of residual BBR(50 mg/mL) metabolized in the gut microbiota under the influence of an inhibitor(voriconazole,3.5 μg/mL). *P <0.05;**P <0.01.(E)Comparison of the M1 content produced by BBR(50 mg/mL)metabolism in the gut microbiota under the influence of an inhibitor(voriconazole,3.5 μg/mL).**P <0.01;***P <0.001.(F)Comparison of the M2 content produced by BBR(50 mg/mL)metabolism in the gut microbiota under the influence of an inhibitor(voriconazole,3.5 μg/mL). * P <0.05; ** P <0.01.

    Fig.3.Metabolism of BBR in the liver and kidney system in vitro.(A and B)Comparison of M1 and M2 levels produced by BBR(50 mg/mL)metabolism in liver homogenate under the influence of an inhibitor (voriconazole, 3.5 μg/mL). (C and D) Comparison of M1 and M2 levels produced by BBR (50 mg/mL) metabolism in kidney microsomes under the influence of an inhibitor(voriconazole,3.5 μg/mL).(E and F)Comparison of M1 and M2 levels produced by BBR(50 mg/mL)metabolism in kidney homogenate under the influence of an inhibitor (voriconazole, 3.5 μg/mL). (G and H) Comparison of M1 and M2 levels produced by BBR (50 mg/mL) metabolism in kidney microsomes under the influence of an inhibitor (voriconazole, 3.5 μg/mL).

    Thus, it could be inferred that voriconazole reduced the metabolic capacity of BBR by inhibiting the enzyme activity and slowing the BBR metabolic process,which finally increased thet1/2,AUC andCmaxof BBR in mouse plasma.

    3.3. Pharmacokinetics of M1 and M2 in vivo

    The production of M1 was more than that of M2 in mice after oral administration of BBR.In addition,the M1 and M2 levels were all below the lower limit of quantitation(1 ng/mL)and could not be detected at any of the time points under the influence of voriconazole (Figs. 1F and G), which indirectly proved that voriconazole had entered the gut microbiota.It indicated that after oral administration of voriconazole, BBR could not be converted to M1 or M2 by the demethylation pathway in vivo.Therefore,combined with the results of pharmacokinetic studies, this result indicated that the demethylation process of BBR in vivo was mediated by CYP51.

    Fig.4.Metabolism of BBR in standard bacterial strains in vitro.(A)Comparison of M1 content produced by BBR metabolism in 14 standard bacterial strains.*P <0.05;**P <0.01.(B and C) Percentage of BBR metabolized by 4 standard bacterial strains after 48 h and 72 h. * P <0.05; ** P <0.01. (D and E) Activity of CYP51 in 4 standard bacterial strains after metabolism of BBR for 48 h and 72 h. * P <0.05; ** P <0.01; *** P <0.001. (F and G) Comparison of M1 and M2 levels produced by BBR (50 mg/mL) metabolism in 4 standard bacterial strains for 72 h under the influence of an inhibitor (voriconazole, 3.5 μg/mL). * P <0.05; ** P <0.01; ND: not detected. (H) Comparison of CYP51 activity in 4 standard bacterial strains after metabolism of BBR (50 mg/mL) for 72 h under the influence of an inhibitor (voriconazole, 3.5 μg/mL) ** P <0.01; *** P <0.001.

    3.4. Metabolism of BBR by the mice gut microbiota in vitro

    Different concentrations of BBR (10, 50, and 100 mg/mL) and mouse colon contents were mixed and incubated for 72 h,and the contents of BBR, M1 and M2 were determined. After 12 h of incubation, the production of M1 was 15, 47, and 76 μg/mL while the production of M2 was 44, 98, and 131 μg/mL, respectively. After 72 h of incubation,the production of M1 was 47,100,and 113 μg/mL while the production of M2 was 93,292,and 337 μg/mL.From the above results,it could be known that the production of M2(Fig.2C)was nearly 3 times (the range was 1.73-2.98) higher that of M1(Fig. 2B) when BBR was metabolized by gut microbiota in vitro.After 72 h of incubation,BBR could not be completely metabolized(Fig. 2A). At the same time, the percentage of BBR metabolized at each concentration was different, and the percentage of BBR metabolized at 10, 50, and 100 mg/mL concentrations decreased sequentially. It was speculated that the concentration of intestinal bacteria and the activity of CYP51 in each system were constant,so the metabolic capacity of BBR was certain,which further resulted in the difference in the percentage of BBR metabolism at each concentration. In addition, BBR could be metabolized in the mouse intestinal microsomes and M1 and M2 were produced. However,the production of M1 and M2 was very low (Figs. S1A and B). The production of M1 was decreased by 21%,25%,and 20%at 30,60,and 120 min after adding voriconazole(Fig.S1A)and the production of M2 was decreased by 28%, 26%, and 30% at 30, 60, and 120 min,respectively(Fig.S1B).This showed that the demethylation of BBR in the intestine was mainly mediated by gut microbiota and CYP51 played a key role in the metabolism of BBR.

    However, the percentage of residual BBR was significantly increased (Fig. 2D) after the addition of voriconazole (3.5 μg/mL).Furthermore, the production of M1 (Fig. 2E) and M2 (Fig. 2F) was significantly decreased sequentially compared with that in the BBR group. This further demonstrated that voriconazole could specifically inhibit the activity of CYP51, thereby reducing the ability of intestinal bacteria to metabolize BBR and produce M1 and M2.

    3.5. Metabolism of BBR in the liver and kidney system in vitro

    The mouse liver homogenates and liver microsomes were mixed and incubated with BBR(50 mg/mL)and voriconazole(3.5 μg/mL),respectively. Then, the levels of M1 and M2 in the mixture were determined at different time points. After the addition of voriconazole (3.5 μg/mL), BBR could still be metabolized in the liver homogenate, and M1 and M2 were produced, but the production was partially reduced (Figs. 3A and B). Similar results were also observed in the liver microsomes (Figs. 3C and D).

    We also performed a comparison with the metabolic process of BBR in the renal system in vitro. The mouse kidney homogenates and kidney microsomes were treated as described above.After the addition of voriconazole(3.5 μg/mL),BBR could still be metabolized in the kidney homogenate, and M1 and M2 were produced,although also at reduced levels(Figs.3E and F).In addition,similar results were observed in kidney microsomes (Figs. 3G and H).

    This indicated that the addition of voriconazole to the liver and kidney homogenates could inhibit the activity of CYP51, thereby reducing the amount of M1 and M2 produced by BBR metabolism,but the reduction ratio was much lower than that in the gut microbiota.Therefore,it was hypothesized that the key enzyme in the demethylation pathway in the gut was CYP51. In addition, the production of M1 and M2 in kidney homogenate was the lowest(Figs.S1C and D).Compared with the group of kidney homogenate,the production of M1 in liver homogenate was increased by 27%,38%,and 4%at 30,60,and 120 min(Fig.S1C);the production of M2 in liver homogenate increased by 657%, 724%, and 315% at 30, 60,and 120 min, respectively (Fig. S1D). Nevertheless, it could still be seen that the production of M1 and M2 in liver homogenate was much lower than that in gut microbiota (Figs. S1E and F). The production of M1 in gut microbiota was 52.59,69.31,and 84.16 μg/mL at 30, 60, and 120 min (Fig. S1E); the production of M2 in gut microbiota was 132.34,212.45,and 267.40 μg/mL at 30,60,and 120 min,respectively(Fig.S1F).Therefore,it was hypothesized that the gut microbiota was more important to the demethylation of BBR and the key enzyme in the demethylation pathway in the gut was CYP51. In view of the fact that enzymes in the liver and kidneys were likely to participate in the metabolism of BBR in the body,and under the action of voriconazole,BBR still had metabolic processes in the liver and kidneys.Therefore,other metabolic enzymes in the liver and kidneys including drug metabolism P450 enzymes might be involved in the metabolism of BBR. Due to the low absorption rate of BBR, less than 10% of BBR could enter the blood [25].Therefore,although the liver and kidneys had a certain influence on the metabolism of BBR, the demethylation metabolism of BBR in the intestine was more important.

    3.6. Metabolism of BBR in standard bacterial strains in vitro

    Fourteen standard bacterial strains present in the gut microbiota were individually used to investigate the ability of BBR metabolism in vitro, and four standard bacterial strains were selected due to their high production of M1 (Fig. 4A), namely,E. faecalis,S. epidermidis,E. cloacae, andE. faecium.

    These results all directly confirmed the presence of CYP51 in the gut microbiota after each strain was incubated with BBR for 48 h and 72 h. The metabolism of BBR differed among the four strains(Figs. 4B and C). Moreover, the activity of CYP51 differed among different bacterial strains, and the ability of the strains to demethylate BBR was directly proportional to the activity of CYP51(Figs. 4D and E). It was verified that CYP51 was indeed present in the gut microbiota and participated in demethylation-related metabolism.

    However, the level of M1 produced by each strain was significantly reduced (Fig. 4F), while the level of M2 produced by each strain was below the lower limit of quantitation and could not be detected(Fig.4G)after the addition of voriconazole(3.5 μg/mL)for 72 h.In addition,the activity of CYP51 in the four standard bacterial strains incubated with 50 mg/mL BBR for 72 h was not significantly different from that in the strains alone. After the addition of voriconazole (3.5 μg/mL), CYP51 activity was reduced (Fig. 4H).

    This result indicated that voriconazole, a specific inhibitor of CYP51, inhibited most of the activity of CYP51 in bacterial strains,significantly reduced the ability of CYP51 to demethylate BBR for metabolism, and prevented the production of M1 and M2. It was further verified that CYP51 was present in the gut microbiota and is the key enzyme used by the gut microbiota to metabolize BBR to produce a demethylated metabolite.

    3.7. 16S rRNA analysis of the feces of ICR mice after oral administration of BBR

    To explore how BBR affects the gut microbiota, ICR mice were orally administered BBR. Then, the feces of the ICR mice were collected 24 h later and subjected to 16S rRNA sequencing and data analysis, as shown in Fig.5. Compared with the control group, the BBR-treated group exhibited a significant increase in the abundance of one genus(Parabacteroides)(P<0.05,marked in a red“Δ”)and a significant decrease in the abundances of five genera (Tyzzerella 3, Rikenellaceae RC9 gut group, Roseburia, Tyzzerella, Ruminococcus 1) (P<0.05, marked in a blue “Δ”).Parabacteroidesis a potential probiotic genus. Recent studies have found thatParabacteroidesspecies could produce succinate and secondary bile acids to resist body obesity and metabolic dysfunction[26,27];the reduced abundance ofRuminococcus 1validated the role of BBR.Zhang et al. [28] found that the abundance ofRuminococcus 1was significantly increased in rats with high-fat-induced obesity but significantly decreased in rats after BBR administration;Rikenellaceae RC9 gut grouphas also been shown to have important effects on carbohydrates and carbohydrate and lipid metabolism [29].Tyzzerellahas been reported to be greatly enriched in individuals with a high risk of cardiovascular disease [30]. In addition, studies have reported a positive correlation betweenTyzzerella 3and inflammation and hypertension [31,32]. Furthermore, the abundance of one taxon (Porphyromonadaceae) exhibited a significant increase (Fig. S2) at the family level (P< 0.05), which also confirmed the regulatory effect of BBR on the gut microbiota [33].The above results proved that BBR changed the gut microbiota after oral administration and altered its own metabolism by the gut microbiota. To investigate whether voriconazole affected the gut microbiota, ICR mice were orally administered BBR and voriconazole. The abundances ofParabacteroides,Tyzzerella 3,Rikenellaceae RC9 gut group,Roseburia,Tyzzerella, Ruminococcus 1and Porphyromonadaceae, which were originally changed, did not change significantly after the addition of voriconazole (Fig. S3).

    Fig.6.Effect of the CYP51 enzyme lysate on demethylation of BBR.(A)CYP51 plasmid sequence.(B)CYP51 was present in the enzyme lysate(1:marker;2:the protein contained in the precipitate of E. coli BL21 without pet28a-cyp51 before induction; 3: the protein contained in the supernatant of E. coli BL21 without pet28a-cyp51 before induction; 4: the protein contained in the precipitate of E. coli BL21 without pet28a-cyp51 after induction; 5: the protein contained in the supernatant of E. coli BL21 without pet28a-cyp51 after induction; 6: the protein contained in the precipitate of E. coli BL21 with pet28a-cyp51 before induction; 7: the protein contained in the supernatant of E. coli BL21 with pet28acyp51 before induction;8:the protein contained in the precipitate of E.coli BL21 with pet28a-cyp51 after induction;9:the protein contained in the supernatant of E.coli BL21 with pet28a-cyp51 after induction).(C)Relative proportions of lanosterol after incubation for 0,1,2,and 4 h in the enzymatic reaction system of the CYP51 enzyme lysate compared with the control enzyme lysate.*P <0.05.(D)Relative peak area of 14-demethyl-14-dehydrolanosterol(FF-MAS)after 0,1,2,and 4 h of incubation in the enzymatic reaction system of the CYP51 enzyme lysate. * P <0.05; ** P <0.01; ND: not detected. (E and F) Relative proportions of M1 and M2 after 0,1, 2, and 4 h of incubation in the CYP51 enzyme lysate compared with the control enzyme lysate. * P <0.05; ** P <0.01.

    3.8. Metabolism of BBR in CYP51 enzyme lysate

    Recombinant plasmid containing theCYP51gene was constructed(Figs.6A and S4A),and transformed intoE.coliBL21(DE3)cells.The CYP51 protein was expressed inE.colias accessed by SDSPAGE analysis (Fig. 6B). Lanosterol, the classic substrate of CYP51,was selected to verify the function of the CYP51 enzyme lysate.As shown in Fig.6C,the lanosterol level decreased significantly under the action of CYP51 enzyme lysate compared with the control.The production ratio of its demethylated metabolite,FF-MAS,increased significantly(Fig.6D),while the FF-MAS level was below the lower limit of quantitation after the reaction of lanosterol with the control enzyme lysate (Fig. S4B). BBR was added to the CYP51 enzyme lysate system, and the production ratios of M1 and M2 were significantly increased compared with that of the control (Figs. 6E and F), which verified that CYP51 was the key enzyme of the gut microbiota that promoted the metabolism of BBR to produce demethylated metabolites.

    4. Conclusion

    BBR is a safe drug with multiple therapeutic effects in the clinic.Due to the low absorption rate of BBR in the gut microbiota, the activity of its metabolites is particularly important.In this research,it was first suggested that CYP51 was present in the gut microbiota,and BBR was metabolized by CYP51 in the intestine to produce demethylated metabolites M1 and M2, which provided a basis for the study of metabolic conversion mechanisms of various isoquinoline alkaloids in vivo and expanded our understanding of the role of the gut microbiota in drug metabolism with demethylation reaction.

    Declaration of competing interest

    The authors declare that there are no conflicts of interest.

    Acknowledgments

    The project was supported by CAMS Innovation Fund for Medical Sciences (CIFMS, Grant No.: 2016-I2M-3-011, China), the National Natural Science Foundation of China (Grant Nos.: 81803613 and 81973290), Beijing Key Laboratory of Non-Clinical Drug Metabolism and PK/PD study (Grant No.: Z141102004414062,China), Beijing Natural Sciences Fund Key Projects (Grant No.:7181007)and the National Megaproject for Innovative Drugs(Grant No.:2018ZX09711001-002-002).We would like to thank Shimadzu(China) Co., Ltd. for technological support.

    Appendix A. Supplementary data

    Supplementary data to this article can be found online at https://doi.org/10.1016/j.jpha.2020.10.001.

    麻豆乱淫一区二区| xxx大片免费视频| 午夜福利高清视频| 丝袜喷水一区| 免费看av在线观看网站| 久久久久国产精品人妻一区二区| 日韩亚洲欧美综合| 一个人观看的视频www高清免费观看| 久久影院123| 午夜激情久久久久久久| 久久99热这里只有精品18| 亚洲天堂av无毛| 亚洲精品视频女| 夜夜看夜夜爽夜夜摸| 欧美人与善性xxx| 在线观看一区二区三区激情| 又爽又黄a免费视频| 亚洲美女搞黄在线观看| 美女视频免费永久观看网站| 美女高潮的动态| 国产精品国产三级国产专区5o| 你懂的网址亚洲精品在线观看| 一级av片app| 欧美xxxx黑人xx丫x性爽| 精品少妇久久久久久888优播| 精品一区在线观看国产| 一边亲一边摸免费视频| 国产男人的电影天堂91| 国产成人91sexporn| 丰满人妻一区二区三区视频av| 国产伦精品一区二区三区视频9| 免费高清在线观看视频在线观看| 日产精品乱码卡一卡2卡三| 日日啪夜夜撸| 国产精品国产三级专区第一集| 汤姆久久久久久久影院中文字幕| 亚洲av国产av综合av卡| 男女啪啪激烈高潮av片| 亚洲第一区二区三区不卡| 免费观看av网站的网址| 国产高清不卡午夜福利| 亚洲av二区三区四区| 少妇的逼水好多| 看黄色毛片网站| 午夜免费观看性视频| 久久精品熟女亚洲av麻豆精品| 99热这里只有是精品50| 老师上课跳d突然被开到最大视频| 伊人久久国产一区二区| 涩涩av久久男人的天堂| 国产91av在线免费观看| 亚洲久久久久久中文字幕| 欧美日韩亚洲高清精品| 一级av片app| 日韩制服骚丝袜av| 国产精品久久久久久精品电影| 日本色播在线视频| 免费观看a级毛片全部| 中文字幕av成人在线电影| 日韩人妻高清精品专区| 日韩人妻高清精品专区| 少妇人妻一区二区三区视频| 91久久精品电影网| 亚洲精品亚洲一区二区| 国产真实伦视频高清在线观看| freevideosex欧美| 22中文网久久字幕| 欧美精品一区二区大全| 亚洲欧美精品自产自拍| 大话2 男鬼变身卡| 久久精品人妻少妇| 少妇人妻一区二区三区视频| 亚洲成人精品中文字幕电影| 亚洲真实伦在线观看| 国产一区二区三区av在线| 人妻夜夜爽99麻豆av| 欧美三级亚洲精品| 欧美日韩一区二区视频在线观看视频在线 | 亚洲欧美成人综合另类久久久| 日韩精品有码人妻一区| 亚洲美女视频黄频| 免费不卡的大黄色大毛片视频在线观看| 国产欧美另类精品又又久久亚洲欧美| 精品久久国产蜜桃| 性插视频无遮挡在线免费观看| av国产精品久久久久影院| 在线观看免费高清a一片| 毛片一级片免费看久久久久| 午夜老司机福利剧场| 精品一区二区三区视频在线| 免费看av在线观看网站| 内地一区二区视频在线| 日本一本二区三区精品| 国产高清三级在线| 亚洲精品一二三| 免费看不卡的av| 赤兔流量卡办理| 亚洲精华国产精华液的使用体验| 亚洲,欧美,日韩| 看免费成人av毛片| 99久久九九国产精品国产免费| 熟女电影av网| 你懂的网址亚洲精品在线观看| 我的老师免费观看完整版| 两个人的视频大全免费| 日韩人妻高清精品专区| 日本与韩国留学比较| 一区二区三区精品91| 最新中文字幕久久久久| 亚洲综合色惰| 精品久久国产蜜桃| 91久久精品国产一区二区三区| 在线观看美女被高潮喷水网站| 最近中文字幕高清免费大全6| videossex国产| 天美传媒精品一区二区| 美女cb高潮喷水在线观看| 2021少妇久久久久久久久久久| 黄色视频在线播放观看不卡| 超碰97精品在线观看| 国产精品伦人一区二区| 久热久热在线精品观看| 在线亚洲精品国产二区图片欧美 | 尤物成人国产欧美一区二区三区| 美女视频免费永久观看网站| av在线app专区| 成年女人在线观看亚洲视频 | 黑人高潮一二区| 久久久精品94久久精品| 国精品久久久久久国模美| 一本一本综合久久| 久久人人爽人人片av| 久久久久久久国产电影| 国产成人精品一,二区| 亚洲人成网站在线观看播放| 岛国毛片在线播放| 欧美精品人与动牲交sv欧美| 精华霜和精华液先用哪个| 亚洲av.av天堂| 我要看日韩黄色一级片| 深爱激情五月婷婷| 六月丁香七月| 黄色视频在线播放观看不卡| 男人狂女人下面高潮的视频| 一级爰片在线观看| 久久亚洲国产成人精品v| 欧美最新免费一区二区三区| 久久精品人妻少妇| 亚洲美女视频黄频| 午夜免费鲁丝| 中文乱码字字幕精品一区二区三区| 国产精品久久久久久久久免| 亚洲精品乱码久久久v下载方式| 可以在线观看毛片的网站| 少妇 在线观看| 99热6这里只有精品| 成年av动漫网址| 秋霞伦理黄片| 黄色配什么色好看| 边亲边吃奶的免费视频| 国产真实伦视频高清在线观看| 18禁裸乳无遮挡动漫免费视频 | 成年女人在线观看亚洲视频 | 女人十人毛片免费观看3o分钟| 99久久精品国产国产毛片| av国产精品久久久久影院| 欧美zozozo另类| 一级毛片久久久久久久久女| 啦啦啦中文免费视频观看日本| 亚洲最大成人手机在线| 99热这里只有是精品在线观看| 又爽又黄a免费视频| 伊人久久精品亚洲午夜| av网站免费在线观看视频| 亚洲欧洲国产日韩| 麻豆国产97在线/欧美| 一二三四中文在线观看免费高清| 下体分泌物呈黄色| 内地一区二区视频在线| 国产在线男女| 国产精品久久久久久久电影| 少妇人妻一区二区三区视频| 日韩av免费高清视频| 欧美成人一区二区免费高清观看| 国产视频内射| 九九爱精品视频在线观看| 亚洲精品一二三| 日本-黄色视频高清免费观看| 深夜a级毛片| 综合色av麻豆| 亚洲va在线va天堂va国产| 干丝袜人妻中文字幕| 99久久人妻综合| 久久亚洲国产成人精品v| 午夜福利在线观看免费完整高清在| 亚洲美女视频黄频| 综合色丁香网| 午夜爱爱视频在线播放| 亚洲天堂国产精品一区在线| 国产精品99久久久久久久久| 国内少妇人妻偷人精品xxx网站| 大码成人一级视频| av国产久精品久网站免费入址| 国产精品国产三级国产专区5o| 精品久久久久久久人妻蜜臀av| 午夜福利在线观看免费完整高清在| 看非洲黑人一级黄片| 久久影院123| 国产精品久久久久久精品电影小说 | 最近最新中文字幕免费大全7| 久久人人爽人人爽人人片va| 18禁在线无遮挡免费观看视频| 国产精品国产三级国产专区5o| 精品视频人人做人人爽| 日韩欧美 国产精品| 亚洲av免费在线观看| 欧美xxxx黑人xx丫x性爽| 国产v大片淫在线免费观看| 亚洲,欧美,日韩| 国产精品成人在线| 成人特级av手机在线观看| 久久久久网色| 国产高清三级在线| 黄色配什么色好看| 五月伊人婷婷丁香| 国产一区二区在线观看日韩| 久久99热这里只有精品18| 偷拍熟女少妇极品色| 国产精品一区www在线观看| 国产乱来视频区| 别揉我奶头 嗯啊视频| 又黄又爽又刺激的免费视频.| 国产在线男女| av网站免费在线观看视频| xxx大片免费视频| 2021少妇久久久久久久久久久| 亚洲精品乱码久久久v下载方式| 在线精品无人区一区二区三 | freevideosex欧美| 97在线视频观看| 日韩 亚洲 欧美在线| 真实男女啪啪啪动态图| 99视频精品全部免费 在线| 成人国产麻豆网| 亚洲色图综合在线观看| 精品99又大又爽又粗少妇毛片| 日韩国内少妇激情av| 久久热精品热| a级毛片免费高清观看在线播放| 亚洲av免费高清在线观看| 国产成人a区在线观看| av.在线天堂| 亚洲欧美成人综合另类久久久| 女人十人毛片免费观看3o分钟| 久久精品久久久久久久性| 久久久欧美国产精品| 久久久久久九九精品二区国产| 国产男女内射视频| 亚洲精品日本国产第一区| 成人美女网站在线观看视频| 欧美最新免费一区二区三区| 草草在线视频免费看| 精品久久久久久久末码| 精品人妻一区二区三区麻豆| 伦理电影大哥的女人| 国产亚洲5aaaaa淫片| 欧美国产精品一级二级三级 | 婷婷色麻豆天堂久久| 亚洲av福利一区| 日韩免费高清中文字幕av| 亚洲av在线观看美女高潮| 亚洲av二区三区四区| 在线观看一区二区三区| a级毛片免费高清观看在线播放| 久久精品夜色国产| 欧美变态另类bdsm刘玥| 天天躁夜夜躁狠狠久久av| 亚洲国产欧美在线一区| 亚洲精品日本国产第一区| 联通29元200g的流量卡| 肉色欧美久久久久久久蜜桃 | 中文乱码字字幕精品一区二区三区| 精品久久久噜噜| 中文字幕av成人在线电影| 九色成人免费人妻av| av女优亚洲男人天堂| 中文字幕久久专区| 日韩欧美 国产精品| 欧美另类一区| 国产黄色视频一区二区在线观看| 一级毛片aaaaaa免费看小| 1000部很黄的大片| 九色成人免费人妻av| 亚洲欧美中文字幕日韩二区| 美女被艹到高潮喷水动态| 国产乱人视频| 国产精品爽爽va在线观看网站| 午夜激情福利司机影院| 一级毛片aaaaaa免费看小| 亚洲精品视频女| 噜噜噜噜噜久久久久久91| 久久99热6这里只有精品| 日日摸夜夜添夜夜添av毛片| 亚洲自拍偷在线| av国产精品久久久久影院| 精品亚洲乱码少妇综合久久| 一个人看视频在线观看www免费| 久久精品国产自在天天线| 亚洲aⅴ乱码一区二区在线播放| 亚洲精品中文字幕在线视频 | 九九久久精品国产亚洲av麻豆| 亚洲精品久久午夜乱码| 成人亚洲精品av一区二区| 夫妻性生交免费视频一级片| 97超视频在线观看视频| 日韩亚洲欧美综合| 久热这里只有精品99| 国产高潮美女av| 青青草视频在线视频观看| 内地一区二区视频在线| 欧美日韩综合久久久久久| 精品午夜福利在线看| 国产淫片久久久久久久久| 80岁老熟妇乱子伦牲交| 国产黄色免费在线视频| 美女xxoo啪啪120秒动态图| 久久久久久久大尺度免费视频| 五月开心婷婷网| 99热网站在线观看| 亚洲av免费高清在线观看| 亚洲久久久久久中文字幕| 少妇的逼水好多| 国产精品成人在线| 丝袜美腿在线中文| 男女那种视频在线观看| 日韩人妻高清精品专区| 视频中文字幕在线观看| 亚洲精品成人av观看孕妇| 中文资源天堂在线| 精品国产三级普通话版| 99久国产av精品国产电影| 欧美变态另类bdsm刘玥| 五月伊人婷婷丁香| 国模一区二区三区四区视频| 成人综合一区亚洲| 国产乱人视频| 69人妻影院| 又黄又爽又刺激的免费视频.| 国产永久视频网站| 久久ye,这里只有精品| 免费黄网站久久成人精品| .国产精品久久| 一边亲一边摸免费视频| 日本黄色片子视频| 亚洲av二区三区四区| 大片电影免费在线观看免费| 久久久久性生活片| 白带黄色成豆腐渣| 国产成人精品婷婷| 成人鲁丝片一二三区免费| 大陆偷拍与自拍| 一级片'在线观看视频| 国产视频内射| 美女脱内裤让男人舔精品视频| 久久久国产一区二区| 国产精品一二三区在线看| av天堂中文字幕网| 国产av不卡久久| 国产精品99久久99久久久不卡 | 国产片特级美女逼逼视频| 97超碰精品成人国产| 少妇丰满av| 在线 av 中文字幕| 亚洲,欧美,日韩| 色吧在线观看| 人妻系列 视频| 成人亚洲精品一区在线观看 | 亚洲精品乱码久久久久久按摩| 搡老乐熟女国产| av线在线观看网站| 中文字幕av成人在线电影| 69av精品久久久久久| 亚洲人成网站高清观看| 国产精品偷伦视频观看了| av卡一久久| 国产又色又爽无遮挡免| 精品久久久久久电影网| 国产片特级美女逼逼视频| 精品少妇黑人巨大在线播放| 亚洲精品乱久久久久久| 少妇人妻精品综合一区二区| 国产欧美亚洲国产| 亚洲自偷自拍三级| 欧美3d第一页| 国产精品久久久久久久电影| 九九久久精品国产亚洲av麻豆| 国产在视频线精品| 午夜视频国产福利| 少妇被粗大猛烈的视频| 在现免费观看毛片| 搞女人的毛片| 大码成人一级视频| 亚洲av不卡在线观看| 制服丝袜香蕉在线| 69人妻影院| 午夜精品一区二区三区免费看| 国产精品成人在线| 亚洲精品国产av成人精品| 欧美变态另类bdsm刘玥| 日本wwww免费看| av女优亚洲男人天堂| 国产成人精品福利久久| 国产男女内射视频| 久久久久久久大尺度免费视频| 人妻夜夜爽99麻豆av| 国精品久久久久久国模美| 精品久久久噜噜| 日本色播在线视频| 好男人在线观看高清免费视频| 国产精品.久久久| 国产一区亚洲一区在线观看| 性色av一级| 大话2 男鬼变身卡| 69人妻影院| 国产探花在线观看一区二区| 亚洲成人中文字幕在线播放| 亚洲最大成人手机在线| 欧美激情国产日韩精品一区| 亚洲国产欧美在线一区| 国产v大片淫在线免费观看| 成人毛片60女人毛片免费| 少妇猛男粗大的猛烈进出视频 | 黑人高潮一二区| 如何舔出高潮| 男女边摸边吃奶| av在线播放精品| 欧美变态另类bdsm刘玥| 国产成人91sexporn| 男人狂女人下面高潮的视频| 99视频精品全部免费 在线| 中文精品一卡2卡3卡4更新| 好男人视频免费观看在线| 国产69精品久久久久777片| 小蜜桃在线观看免费完整版高清| 美女主播在线视频| 久久精品久久精品一区二区三区| 久久人人爽人人片av| 亚洲无线观看免费| 国产亚洲5aaaaa淫片| 麻豆国产97在线/欧美| 毛片一级片免费看久久久久| a级毛片免费高清观看在线播放| 禁无遮挡网站| 小蜜桃在线观看免费完整版高清| 亚洲一级一片aⅴ在线观看| 丝袜脚勾引网站| 国产av码专区亚洲av| 一二三四中文在线观看免费高清| 亚洲无线观看免费| 日本猛色少妇xxxxx猛交久久| 直男gayav资源| 亚洲精品,欧美精品| 五月天丁香电影| 波野结衣二区三区在线| 在线观看美女被高潮喷水网站| 赤兔流量卡办理| 777米奇影视久久| 国产久久久一区二区三区| 亚洲自拍偷在线| 国产 精品1| 国产成人精品久久久久久| 69av精品久久久久久| 欧美+日韩+精品| 国产精品三级大全| 久久精品国产亚洲av天美| av在线观看视频网站免费| 五月天丁香电影| 99精国产麻豆久久婷婷| 最近中文字幕高清免费大全6| 国产伦精品一区二区三区四那| 免费av毛片视频| 蜜桃久久精品国产亚洲av| 国产精品无大码| 在现免费观看毛片| 精品国产一区二区三区久久久樱花 | 天堂网av新在线| eeuss影院久久| 99热全是精品| av网站免费在线观看视频| 国产亚洲精品久久久com| 欧美最新免费一区二区三区| av国产精品久久久久影院| 麻豆成人av视频| 精品久久久久久久久av| 乱码一卡2卡4卡精品| 国产伦精品一区二区三区视频9| 欧美3d第一页| 午夜日本视频在线| 亚洲欧美中文字幕日韩二区| 亚洲欧美一区二区三区黑人 | 又黄又爽又刺激的免费视频.| 亚洲欧美成人综合另类久久久| a级毛色黄片| 男女啪啪激烈高潮av片| 精品一区二区三区视频在线| 一级毛片黄色毛片免费观看视频| 91精品伊人久久大香线蕉| 久久鲁丝午夜福利片| 深爱激情五月婷婷| 日韩成人伦理影院| 久久久久久国产a免费观看| 免费少妇av软件| 我的女老师完整版在线观看| 高清在线视频一区二区三区| 免费播放大片免费观看视频在线观看| 一级av片app| 2021天堂中文幕一二区在线观| 亚洲精品第二区| 永久免费av网站大全| 在现免费观看毛片| av.在线天堂| 国产亚洲精品久久久com| 在线a可以看的网站| 精品久久久精品久久久| 国产熟女欧美一区二区| 国产免费视频播放在线视频| 大香蕉久久网| 精品少妇久久久久久888优播| 十八禁网站网址无遮挡 | 看十八女毛片水多多多| 在线观看免费高清a一片| 国产精品.久久久| 在线观看免费高清a一片| 国产毛片a区久久久久| 日本av手机在线免费观看| 日韩国内少妇激情av| 69人妻影院| 色综合色国产| 18禁在线无遮挡免费观看视频| 亚洲成色77777| videossex国产| 国产有黄有色有爽视频| 搡女人真爽免费视频火全软件| 亚洲精品成人av观看孕妇| 国产精品福利在线免费观看| 蜜桃亚洲精品一区二区三区| 看非洲黑人一级黄片| 亚洲人成网站在线播| 亚洲美女视频黄频| 老女人水多毛片| 亚洲自偷自拍三级| 日韩一区二区视频免费看| 狂野欧美激情性xxxx在线观看| 日日摸夜夜添夜夜添av毛片| 美女xxoo啪啪120秒动态图| 天天一区二区日本电影三级| 亚洲国产精品成人综合色| 久久女婷五月综合色啪小说 | 久久精品国产亚洲av天美| 日韩制服骚丝袜av| 老女人水多毛片| 一级片'在线观看视频| 久久精品熟女亚洲av麻豆精品| 欧美少妇被猛烈插入视频| 91精品一卡2卡3卡4卡| 欧美另类一区| av在线老鸭窝| 又大又黄又爽视频免费| 狠狠精品人妻久久久久久综合| 自拍偷自拍亚洲精品老妇| 国产亚洲av嫩草精品影院| 一级毛片黄色毛片免费观看视频| 国产精品熟女久久久久浪| 午夜福利高清视频| 2021少妇久久久久久久久久久| 91久久精品电影网| 99热6这里只有精品| 亚洲精品成人久久久久久| 亚洲国产成人一精品久久久| 日韩制服骚丝袜av| 男女那种视频在线观看| 日本猛色少妇xxxxx猛交久久| 亚洲欧美成人精品一区二区| 欧美日韩视频高清一区二区三区二| 久久久久国产网址| 午夜老司机福利剧场| 午夜福利在线观看免费完整高清在| 成年人午夜在线观看视频| 神马国产精品三级电影在线观看| 美女高潮的动态| 免费播放大片免费观看视频在线观看| 国产大屁股一区二区在线视频| 精品午夜福利在线看| 久热这里只有精品99| 久久人人爽av亚洲精品天堂 | 夜夜看夜夜爽夜夜摸| 人妻少妇偷人精品九色| 久久99精品国语久久久| 啦啦啦啦在线视频资源| 少妇被粗大猛烈的视频| 亚洲天堂国产精品一区在线| 国产黄a三级三级三级人| 国产毛片在线视频| 一个人观看的视频www高清免费观看| 最近中文字幕2019免费版| 丝袜脚勾引网站| 国产一区二区三区av在线| 性色av一级| 国产真实伦视频高清在线观看| 中文字幕制服av| 国产成人免费观看mmmm| 秋霞伦理黄片| 偷拍熟女少妇极品色| 久久久久久久久久人人人人人人| 男人爽女人下面视频在线观看|