Oropharyngeal aspiration of bleomycin: An alternative experimental model of pulmonary fibrosis developed in Swiss mice

Abstract

Objective:Pulmonary fibrosis (PF) is a progressive and predominantly lethal form of several interstitial lung diseases with limited current therapeutics; it is, therefore, essential to develop a simple, homogeneous, and noninvasive disease model to investigate possible anti-fibrotic approaches. The present study is designed to develop oropharyngeal aspiration (OPA) model of bleomycin (BLM)-induced PF as a simple and alternative to intratracheal (IT) administration of BLM in Swiss mice strain.Materials and Methods:Mice were divided into two groups, BLM-treated and normal control. BLM via OPA (2 IU/kg) was used to induce PF. Water for injection was used as a vehicle in control animals. Body weights were measured once in a week, and the study was continued for 21 days. At the end of the study, animals were euthanized and bronchoalveolar lavage fluid was collected and subjected to lymphocytes count, estimation of albumin and protein levels. Lung tissues were collected, and various biochemical assays (malondialdehyde, glutathione, nitric oxide, hydroxyproline) and molecular techniques including ELISA and Western blot were performed to investigate the effect of OPA-BLM. Further, histopathology and Masson's trichrome staining techniques were performed in lung sections.Results:OPA administration of BLM in Swiss mice significantly induced PF, evident from lung index and morphology. Several oxidative stress parameters and hydroxyproline assay revealed the significant (P < 0.05) induction of PF. Further results obtained from histopathology, Masson's trichrome staining, ELISA, and Western blot confirmed the significant induction of PF via OPA-BLM.Conclusion:BLM administration by OPA route in Swiss mice can be used as a simple, homogeneous, and noninvasive model of inducing PF and to investigate the effect of various anti-fibrotic agents as an alternative to IT-BLM.

An Adaptogen: Withaferin A Ameliorates in Vitro and in Vivo Pulmonary Fibrosis by Modulating the Interplay of Fibrotic, Matricelluar Proteins, and Cytokines

“…Bronchoalveolar lavage fluid was collected thrice from each animal by passing 1 mL of ice-cold PBS into the trachea, followed by gentle aspiration of the fluid by inserting a catheter in the trachea ( Bale et al, 2016 ). The percentage recovery of lavage fluid was approximately 85% and did not differ among the animal groups significantly.…”

Bleomycin Revisited: A Direct Comparison of the Intratracheal Micro-Spraying and the Oropharyngeal Aspiration Routes of Bleomycin Administration in Mice

“…Furthermore, the IT delivery of BLM through a microspray aerosolizer ( 8 ) has been shown to yield more reproducible results and more homogenous distribution of fibrotic lesions than IT instillation/injection ( 9 ). Following the example of other drugs and agents ( 10 – 13 ), an alternative way of administering BLM in the trachea, namely oropharyngeal aspiration (OA), has been recently introduced ( 14 , 15 ). However, the IT and OA routes of BLM administration have not been directly compared ( 3 ).…”

Respiratory Tract Deposition and Distribution Pattern of Microparticles in Mice Using Different Pulmonary Delivery Techniques

“…As mentioned earlier, these techniques require technical expertise and anesthetization of animals prior to administration, and repeated dosing may cause inflammation and injury to the trachea. An alternative technique to IT installation and tracheostomy is oropharyngeal aspiration, which can potentially overcome some of the challenges mentioned above [ 23 , 24 , 31 ]. Lakatos et al compared oropharyngeal aspiration to IT instillation to establish a silica-induced fibrosis mouse model and observed that administration of silica particles by aspiration resulted in a more uniform pulmonary distribution with minimal intra-animal variability [ 32 ].…”

“…Price et al recently discussed in detail the importance of animal model selection when evaluating an inhaled product in the preclinical stage [ 20 ]. Most of the published papers evaluating inhaled drugs employ small animal models such as mice and rats due to ease of availability, affordability, and handling [ 3 , 7 , 22 , 23 , 24 ]. In this study, we evaluated three widely reported preclinical inhalation (direct) techniques: the MicroSprayer ® Aerosolizer (Penn-Century, Wyndmoor, PA, USA; recently discontinued), the BioLite Intubation System (Braintree Scientific, Braintree, MA, USA), and oropharyngeal aspiration.…”