This study investigated the effect of
Gualou Xiebai Decoction on rats with
bleomycin-induced
pulmonary fibrosis. The rats were randomly divided into a control group, a model group, a low-dose
Gualou Xiebai Decoction group(2.4 g·kg~(-1)), a high-dose
Gualou Xiebai Decoction group(4.8 g·kg~(-1)), and
pirfenidone group(150 mg·kg~(-1)). The model of
pulmonary fibrosis was established by intratracheal instillation of
bleomycin in all groups, except the control group. Since the second day of modeling, the corresponding drugs were given to rats by intragastric administration, once a day for 14 d and 28 d. The
hematoxylin-
eosin(HE) staining was used to evaluate the degree of inflammatory injury in lung tissues. The immunofluorescence staining was used to detect the expression of CD68 and CD163 in lung tissues of rats. The levels of
tumor necrosis factor-α(TNF-α) and interleukin-10(IL-10) in serum and brochoalveolar lavage fluid(BALF) were detected by
enzyme-linked
immunosorbent assay(ELISA). The expression of pyroptosis-related genes in lung tissues of rats was detected by qRT-PCR. The results of HE staining and immunofluorescence staining showed that the lung tissue structure was normal in the control group. In addition, there were alveolar collapse or even closure in lung tissues of rats in the model group, with obvious inflammatory cell infiltration, and the expression of CD68 and CD163 was significantly up-regulated. As compared with the model group, the lung tissue structure of rats in the
Gualou Xiebai Decoction groups was significantly improved, with alleviated
inflammation, and the expression of CD68 and CD163 was decreased. As compared with the control group, the level of TNF-α in serum and BALF of rats in the model group was significantly increased(P<0.01), the
mRNA expression levels of alpha smooth muscle actin(α-SMA),
collagen type Ⅰ alpha 1 chain(Col1a1), caspase-1, IL-1β,
IL-18, gasdermin D(Gsdmd), and
NOD-like receptor thermal protein domain associated
protein 3(NLRP3) in lung tissues were significantly increased(P<0.05, P<0.01), and the
mRNA expression level of
E-cadherin was significantly decreased(P<0.01). As compared with the model group, the level of TNF-α in serum and BALF was significantly down-regulated in the high-dose
Gualou Xiebai Decoction group(P<0.05, P<0.01), and that of
IL-10 was up-regulated(P<0.05, P<0.01). The
mRNA expression levels of α-SMA, Col1a1, caspase-1,
IL-18, Gsdmd, NLRP3 and IL-1β in lung tissues were significantly decreased(P<0.05, P<0.01) in the high-dose
Gualou Xiebai Decoction group, and the
mRNA expression level of
E-cadherin was significantly increased(P<0.05, P<0.01). In conclusion,
Gualou Xiebai Decoction can down-regulate the levels of inflammatory factors and related genes and effectively mitigate
pulmonary fibrosis by regulating the pyroptosis pathways.