Preparation of Loki zupa extract
Decoction pieces of Hyssopus cuspidatus Boriss (batch number: C30196901) and Iris halophila Pall. (batch number: G30009407) was purchased from Xinjiang Maidisen traditional uyghur medicine Co. Ltd.(Hotan, China) and identified as pure and eligible medicinal materials for further use. Dried Hyssopus cuspidatus Boriss and Iris halophila Pall was mixed in a ratio of 2:1 (900g:450g) and immersed for 1 hour with 10 times water. They were then boiled twice for an hour. The extracts was collected and filtered, and then concentrated to 4g/ml. They were kept in sterile bottles and stored at 4℃. Loki zupa extract was intragastrically administered to rats in final concentrations of 4g/kg and 8g/kg.
Reagents and chemicals
Dexamethasone sodium phosphate (Dex) was provided by Huashan hospital affiliated to Fudan University. 3R4F research cigarettes were purchased from the University of Kentucky (Lexington, KY, USA) and chloral hydrate was purchased from Aladdin(Shanghai, China). IL-10, IL-6, TNF-α, and IL-1β, MMP-9 TGF-β enzyme-linked immuno-absorbent assay (ELISA) kits were purchased from Raybiotech. (Norcross, USA), SOD, GPX, MDA assay kits was purchased from BioTNT (Shanghai,China), Anti-sPLA2 (ab23705), Anti-IL-6 (ab9324), Anti-Collagen-1 antibody(ab90395) was purchased from Abcam., Anti-TGF-β1 ( #3709 ), anti-smad2/3( #8685), anti-psmad-2/3(#8828), and β-actin (#3700) antibodies were produced by Cell Signaling Technology (Danvers, USA). acetonitrile (pubchem CID:6342),formic acid (pubchem CID:284). Reference standards luteolin(Pubchem CID:5280445), apigenin (Pubchem CID:5280443), luteolin-7-O-β-glucoside (pubchem CID:5280637), apigenin- -7-O-β-glucoside (pubchem CID: 12304093), Diosmetin-7-O-β-glucopyranoside(pubchem, CID: 11016019), rosmarinic acid(pubchem CID:5281792), Chrysin -7-O-β-glucoronide(pubchem CID:14135334) were purchased from Shanghai Winherb Medical & development Co.Ltd(Shanghai, China).
Chromatograph and Mass condition
Agilent series 1260 HPLC instrument equipped with a binary pump, a diode-array detector, an auto-sampler, and a column compartment (Agilent, Waldbronn, Germany), and 6530 Q-TOF mass spectrometer (Agilent, Technologies, Santa Clara, CA) via an ESI interface was used to analyze the active constituents. For the nebulizing and collision gases, High-purity N2 and ultrahigh purity He were used respectively. The experiment was performed on mass spectrometer source in negative ion mode and for qualitative analysis, operated in auto MS/MS scan mode, the parameters were set as follows: end plate offset -500V, capillary voltage, 3500V; temperature, 350℃ and flow rate was 10L/min; nebulizing gas, 30 psi; fragmentor, 125 V; collision energy, 20 eV; molecular weight scanning range was 100-1500 Da. All data were acquired and processed Mass Hunter Workstation Qualitative Analysis Software (Version B. 06.00, Agilent Technologies). The mobile phase was consists of water containing 0.1% v/v acetonitrile (A) and formic acid (B) at flow rate of 0.35 ml/min.
Animals and treatments
40 male Sprague-Dawley (SD) rats, 5-6 week old, weighing 100 ± 20 g, were purchased from Xipuer–Bikai Laboratory Animal Co., Ltd. (Shanghai, China; license number, SCXK [Hu]2008-0016). All the rats (4rats/cage) were placed in a specific pathogen-free (SPF) laboratory in the Animal Center of Shanghai Medical College of Fudan University, at 22 ± 1°C temperature and 50±5% humidity under a 12h light/dark cycle with food and water ad labium. All experimental protocol were performed in accordance with the National Institutes of Health Guidelines for the Care and Use of Laboratory Animals. Procedures involving animals and their care were conducted carefully and treated with minimum pain.
Experiment protocols
After one week accommodation, the rats were divided into the following five groups: the normal group (RA), the CS exposure group (CS), the Loki zupa 4g/kg group (LZ-4), the Loki zupa 8g/kg group (LZ-8), and the Dexamathasone group (Dex), and 8 rats in each group. The normal group was exposed to surrounding air in the room. All the other groups were exposed to side-stream cigarette smoke generated from Buxco smoke generator (Buxco, NC, USA ) by using3R4F cigarettes for 6 days a week. Briefly, rats were placed into the self-made plastic smoking chamber (100*70*40) and 12 cigarettes were used to generate smoke and rats were exposed to the cigarette smoke once a day, 6 days a week . The CS exposure period was 24 weeks. From the first week of exposure, the rats in dexamethasone (Dex) group were treated with 0.1 mg/kg/d dexamethasone. The rats in low and high dose group of Loki zupa were treated with 4g/kg/d and 8g/kg/d. Simultaneously, the rats in room air and model group were intragastrically treated with the same amount of saline water. Body weight was measured weekly to adjust drug administration level and relevant indicators were tested. Before sample collection and lung function analysis, rats were anesthetized by intraperitoneal injection of 40mg/kg, 10% chloral hydrate. After sample collection, remained body of rats was treated according to the injurious medical waste disposal procedure.
Lung function
After anesthetized, each rat was tracheostomized and placed in a lung function detection chamber which was connected to a computer (Buxco, NY, USA) and forced to an average breathing frequency of 150 breaths/min. Functional residual capacity (FRC) was determined by forcing rats to breathe against a closed valve at the mouth. The lungs were inflated by a standard pressure of +30cm H2O. Different lung volumes, such as forced vital capacity (FVC) and the forced expiratory volume in 0.1 second (FEV0.1) , peak expiratory flow(PEF), mid-maximal expiratory flow(MMEF) were then recorded by the pulmonary function maneuver system.
Sample collection
Just after lung function analysis, samples were collected from the anesthetized rats. Blood samples were harvested from the abdominal artery and placed in ice for 2 hours prior to centrifugation. Blood was centrifuged at 3000 rpm for 30 min to obtain serum samples. The supernatant was obtained and stored at -80 °C. Bronchoalveolar lavage fluid was harvested as previously described [23, 24] and stored at −80 °C for the cytokines assay. The right lung was removed and placed in liquid nitrogen for 30 minutes and then stored at −80 °C for further analysis. Death was confirmed after blood and lung sample collection.
Histology and immunohitochemistry
The left lung was harvested for histopathological analysis, fixed with 4% formaldehyde and paraffin-embedded, sliced into 4 um thick sections, positioned on poly-L-lysine-coated slides, and then incubated at 58∘C for 24 hours. Deparaffinized sections were stained with hematoxylin and eosin (H&E) and followed by staining with Masson’s trichrome and periodic acid–Schiff (PAS). Immunohistochemical analysis was performed on 3um formalin fixed sections. PL2AG2 , IL-6 immunohistochemistry were performed as previously describe. Using anti- secretory phospholipase A2 antibody and anti-IL-6 antibody.
Quantification of cytokines
Interleukin-6 (IL-6), Interleukin 1β(IL-1β), Interleukin-10(IL-10), tumor necrosis factor-α(TNF-α), transforming growth factors-β (TGF-β) in the blood serum, and Interleukin-6 (IL-6) and Matrix metalloprotein-9 (MMP-9) were quantified in BALF from various treatment groups by ELISA according to the manufacturer’s protocol.
Antioxidant detection
The levels of superoxide dismutase (SOD), glutathione S—transferase (GSH-ST), glutathione peroxidase (GPX) and malondialdehyde (MDA) content in serum were determined using biochemical kits (BioTNT Co.Ltd.) following the manufacturer’s instructions.
Gene expression profile and bioinformatics
The total RNA of the left lung tissue were extracted and purified,using miRNeasy mini kit (Qiagen, Germany) according to the manufacturer's instructions. Quantitation and quality assessment of the RNA were assessed by using Thremo Nanodrop 2000 (Thermo, USA) and the Agilent 2100 bio-analyzer and the Agilent RNA 6000 Nano Kit (Agilent Technologies, Palo Alto, Calif), respectively. Only RNA samples with an optical density 1.7< A260/A280 <2.2, as well as bio-analyzer results RIN≧7.0 and 28S/18S>0.7 were used in further experiments. cDNA was run on Clariom S Array for rat (Affymetrix, USA) following the manufacturer protocol. Affymetrix GeneChip Scanner 3000 (Affymetrix, USA) was used for signal detection. Expression Console soft-ware (Affymetrix, USA) was used to check the quality.
qPCR analysis
To further validate differential mRNA expression from lung tissues in the COPD rats, the total RNA was extracted form lung tissue using trizol reagent and RNA was converted to cDNA using PrimeScript™ RT Master Mix (Takara) . Quantitative PCR (qPCR) was performed using TB green premix Ex Taq II(Takara),according to the manufacturer's protocol, cDNA samples, appropriate primers, and TB Green Premix Ex Taq II (Takara), ROX Reference Dye(50×, ddH2O. Primers used for qPCR were as follows: as follows: NXT1, forward 5-CTTTGTCAGCTCCGTCTTCA-3, reverse5-CTCAAGGCCTTCTCCAGT TC-3; PLA2G2A, forward 5-GCACA GTTGGCAACCTTTATG-3, reverse 5-CCATCAGCATCATACACTCCTC3; GAPDH, forward 5-AACTCCCATTC CTCCACCTT -3 , reverse 5- GAGGGCCTCTCTCTTGCTCT-3. The thermal cycling conditions included initial incubation of samples at 95 C for 30 sec, followed by appropriate cycles of 95 C for 5 sec, 60 C for 30 sec . GAPDH used as an internal control, and relative expression levels were determined using the 2−ΔΔCt method.
Western blot analysis
The left lung in each group was harvested and total protein was obtained and quantified by a BCA procedure. The isolated total proteins were separated by SDS-PAGE electrophoresis. and then transferred onto PVDF membranes. The membranes were blocked with 5% skim milk in Tris buffer saline–Tween20 (TBST) and washed three times for 5 minutes each time. They were then incubated overnight at 4℃ with their respective antibodies. After washed with TBST three times for 15 minutes, the membranes were incubated with a horseradish peroxidase conjugated secondary antibody (1:10000) for 1 hour at room temperature The membranes were then visualized using the enhanced chemiluminescence detection system (Pierce, USA). The level of β-actin was used as an internal control. Relative intensities were quantified using Quantity One (Bio Rad).
Statistical analysis
The data is expressed as the means ±SDs and was analyzed using one-way analysis of variance (ANOVA) with the turkey multiple comparison test. A p value < 0.05 was considered significant.