Ophiopogonin A attenuates acute lung inflammation in Klebsiella pneumonia mice by regulating RELA (v-rel reticuloendotheliosis viral oncogene homolog A (avian))

Abstract

Ophiopogonin are natural products from the roots of Ophiopogon japonicas with various pharmacological activities. This study explored the mechanism of ophiopogonin A to alleviate the acute inflammation of the lungs of Klebsiella pneumonia. 64 rats were equally assigned into blank control group, injury model group (intratracheal injection of Klebsiella pneumonia to establish Klebsiella pneumonia model), Ophiopogonin A group and Ophiopogonin A+RELA group (combined group, on the basis of injury model group, received RELA mediated ophiopogonin A), with the dose of 10 mg/kg. The histopathological damage was observed under the microscope after HE staining, as well as inflammatory cells in bronchoalveolar lavage fluid (BALF), cytokine levels, and expression of RELA. After HE staining, compared with injury model group, bronchial epithelium structure in Ophiopogonin A group and combination group were relatively intact, the degree of infiltration of inflammatory cells was reduced, and the thickness of alveolar septum was reduced, especially in combination group. The pathological scores of Ophiopogonin A group and combination group were significantly lower, with a further lower score in combination group. The number of inflammatory cells in BALF of rats in Ophiopogonin A group and combination group were significantly reduced, especially in combination group. Similarly, cytokine levels in BALF supernatant and serum of rats in treatment group were reduced, especially in combination group (P < 0.05). Ophiopogonin A could down-regulate RELA, which was further reduced in combination group. In conclusion, ophiopogonin A can reduce the invasion and pathological damage of pathogens to lung tissue and exert an anti-inflammatory ability.