OBJECTIVE

2

To optimize the stir-frying process of

Platycodon grandiflorum

， compare the protective effect of

P. grandiflorum

on lung injury in mice before and after stir-frying， and preliminarily explore the characteristics of “enhanced efficacy through processing” of stir-frying

P. grandiflorum

.

METHODS

2

On the basis of single-factor experiment， the stir-frying time， temperature and frequency were taken as factors， and the comprehensive scores of appearance traits， platycodin D content and alcohol extract content were taken as indexes. Box-Behnken response surface experiment was designed to optimize the stir-frying process of

P. grandiflorum

and verify it. The mice were divided into blank control group， model group， dexamethasone group （positive control drug， 5 mg/kg），

P. grandiflorum

low-dose and high-dose groups （0.6，1.2 g/kg）， fried

P. grandiflorum

low and high dose groups （0.6， 1.2 g/kg）， with 8 mice in each group. The treatment was given once a day for 10 consecutive days. After the last administration， acute lung injury model was established by intratracheal instillation of lipopolysaccharide. The levels of interleukin-6 （IL-6）， IL-1β， tumor necrosis factor-α （TNF-α） in serum and superoxide dismutase （SOD）， myeloperoxidase （MPO） and malondialdehyde （MDA） in lung tissue were detected， lung wet/dry weight ratio and thymus index were calculated， and the pathological changes of lung tissue were observed.

RESULTS

2

The optimum processing conditions were as follows：stir-frying temperature of 120 ℃， stir-frying time of 12 min， stir-frying frequency of 19 r/min； the comprehensive scores of the three batches of process verification were all greater than 97 points， RSD＜3% （

n

＝3）. The results of pharmacodynamic experiments showed that compared with blank control group， the lung dry-wet weight ratio as well as the levels of IL-6， IL-1β， TNF-α， MPO and MDA in the model group were significantly increased （

P

＜0.01）， the thymus index and SOD level were significantly decreased （

P

＜0.01）， and the lung tissue was significantly damaged. Compared with model group， above indexes of the mice in each administration group were significantly improved （

P

＜0.01）， and the lung tissue injury was significantly reduced. At the same dose， except for the lung dry-wet weight ratio， the above indexes of the mice in the stir-fried

P. grandiflorum

groups were significantly improved compared with

P. grandiflorum

groups （

P

＜0.05）， and the lung tissue damage was further reduced.

CONCLUSIONS

2

The optimized stir-frying process is stable and feasible. The protective effect of stir-fried

P. grandiflorum

on acute lung injury in mice is better than that of raw products at the same dosage.