Adenophora Stricta Root Extract Protects Lung Injury from Exposure to Particulate Matter 2.5 in Mice

Abstract

Chronic exposure of particulate matter of less than 2.5 μm (PM2.5) has been considered as one of the major etiologies for various respiratory diseases. Adenophora stricta Miq. is a medicinal herb that has been used for treating respiratory diseases in East Asia. The present study investigated the effect of A. stricta root extract (AsE) on PM2.5-induced lung injury in mice. Oral administration of 100–400 mg/kg AsE for 10 days significantly reduced the PM2.5-mediated increase in relative lung weight, but there was no difference in body weight with AsE administration. In addition, AsE dose-dependently decreased congested region of the lung tissue, prevented apoptosis and matrix degradation, and alleviated mucus stasis induced by PM2.5. Moreover, cytological analysis of bronchioalveolar lavage fluid revealed that AsE significantly inhibited the infiltration of immune cells into the lungs. Consistently, AsE also decreased expression of proinflammatory cytokines and chemokines in lung tissue. Furthermore, AsE administration blocked reactive oxygen species production and lipid peroxidation through attenuating the PM2.5-dependent reduction of antioxidant defense system in the lungs. Therefore, A. stricta root would be a promising candidate for protecting lung tissue from air pollution such as PM2.5.

Adenophora Stricta Root Extract Alleviates Airway Inflammation in Mice with Ovalbumin-Induced Allergic Asthma

“…When body weights were measured on days 0, 1, 7, 14, 15, and 16, there were also no differences in the body weight between vehicle, OVA, and OVA + AsE groups. However, DEXA significantly reduced the body weight from day 7 onward, which was parallel with previous reports that DEXA reduces body weight probably due to muscle atrophy [ 16 , 17 , 20 , 21 ]. Consistently, there were no differences in the body weight gains between the vehicle, OVA, and OVA + AsE groups during the entire experimental period, and DEXA significantly decreased the body weight gain ( Figure 1 a).…”

“…We recently reported that AsE contains vanillic acid 4-β-D-glucopyranoside (VA-4G) [ 16 ]. After column chromatography was additionally performed to purify other bioactive compounds of AsE, 2-furoic acid (FA) and 5-hydroxymethylfurfural (HMF) were further identified by nuclear magnetic resonance spectroscopy.…”

“…Adenophora stricta root extract (AsE) was prepared by spray-drying an aqueous extract of the A. stricta root, as previously described [ 16 ]. After receiving research ethics approval for the protocol from the Institutional Animal Care and Use Committee of Daegu Haany University (approval no., DHU2022-029), the animal experiment was conducted to induce OVA-mediated allergic asthma, as previously reported [ 17 ].…”

“…In contrast, regarding A. triphylla , little has been known about the pharmacological efficacy of A. stricta , except for estrogenic activity. Based on the results from our preliminary screening study that A. stricta exhibited a better pulmonary protective effect than A. triphylla , we recently reported that A. stricta root extract (AsE), which contains about 15 mg/g flavonoids as baicalein equivalent, is a useful medicinal herb to alleviate the lung damage and mucus stasis induced by the inhalation of fine particulate matter less than 2.5 μm [ 16 ]. Moreover, we also demonstrated that AsE is capable of protecting the lung epithelial cells from oxidative stress via inducing nuclear factor erythroid 2-related factor 2-dependent antioxidant genes [ 16 ].…”

“…Based on the results from our preliminary screening study that A. stricta exhibited a better pulmonary protective effect than A. triphylla , we recently reported that A. stricta root extract (AsE), which contains about 15 mg/g flavonoids as baicalein equivalent, is a useful medicinal herb to alleviate the lung damage and mucus stasis induced by the inhalation of fine particulate matter less than 2.5 μm [ 16 ]. Moreover, we also demonstrated that AsE is capable of protecting the lung epithelial cells from oxidative stress via inducing nuclear factor erythroid 2-related factor 2-dependent antioxidant genes [ 16 ]. In order to expand our understanding of the efficacy of A. stricta based on traditional knowledge, and to use A. stricta as a nutraceutical for promoting human health, we would like to further validate the beneficial effects of A. stricta in other types of lung injury models.…”