Development Of An Animal Model For Chronic Obstructive Pulmonary Disease (COPD) And Investigation Of Detoxification Effect Of Apocynum Venetum

Aim: To establish a rat model for chronic obstructive pulmonary disease (COPD) bypassive cigarette smoking plus intratracheal instillation with lipopolysaccharide (LPS), and toinvestigate the protective and therapeutic activities of Apocunum venetum on COPD rats.Methods: Forty SD rats were randomly divided into five groups, including a controlgroup, a model group, and three experimental groups (orally administrated with Apocynumvenetum extract at doses of800mg/mL,400mg/mL and200mg/mL, respectively). The modelgroup was intratracheally instilled with0.1mg lipopolysaccharide (LPS) at Day1and Day10,and the rats were exposed to cigarette smoke for20days for2hours per day (expect for Day1and Day10). Experimental groups were intragastrically administrated with Apocynumvenetum extract of different concentrations (at doses of800mg/mL,400mg/mL and200mg/mL, respectively) for30minutes before exposed to cigarette smoke. After setting upCOPD model, observations of rat signs were conducted; then rat blood samples werecollected, and ratios of carbon monoxide hemoglobin (HbCO) in blood were measured; thebronchoalveolar lavage fluid (BALF) samples were collected, and the total cells in BALFwere counted, and lung tissue slices stained by HE were observed for studying the alternationof morphology.Results: The typical COPD symptoms such as cough and breathing spell were observedin rats from the model group. The percentage of HbCO (HbCO%) in blood collected from themodel group and the total cell counts in BALF collected from the same group weresignificantly higher than the ones of those sampled from the control group. HE stainingshowed that the lung tissues of rats in the model group had typical pathological features ofCOPD and emphysema. The HbCO%in blood and the cell counts in the BALF collected fromexperimental groups administered with Apocynum venetum extract were lower than the onesof those collected from the model group, and HE staining also showed ameliorative symptoms.Furthermore, the protective effect of Apocynum venetum extract of high dose was strongerthan that of medium and low dose groups. Conclusion: A COPD rat model was successfully developed through passive cigarettesmoking plus intratracheal instillation with LPS. Apocynum venetum extracts, especially theone of high dose, had a protective effect on COPD rats by inhibiting the increase of HbCO%in blood and the cell counts in BALF.