Effect of Jaeumganghwa-tang on Production and Secretion of Respiratory Mucus

자음강화탕(滋陰降火湯)이 호흡기 점액의 생성 및 분비에 미치는 영향

Objectives In this study, the effects of Ja-eum-gang-hwa-tang (JGT) on the increase in airway epithelial mucosubstances of rats and ATP- or PMA- or EGF- or TNF-${\alpha}$-induced MUC5AC mucin production and gene expression from human airway epithelial cells were investigated. Materials and Methods Hypersecretion of airway mucus was produced by exposure of $SO_2$ to rats for 3 weeks. The effect of orally-administered JGT for 2 weeks on increased epithelial mucosubstances from tracheal goblet cells of rats was assessed by using histopathological analysis after staining the epithelial tissue with Hematoxylin-eosin and PAS-alcian blue. Possible cytotoxicity of JGT was assessed by investigating the potential damage on kidneys and liver functions by measuring serum GOT/GPT activities and serum BUN concentration of rats and the body weight gain during experiment. Also, the effect of JGT on ATP- or PMA- or EGF- or TNF-${\alpha}$-induced MUC5AC mucin production and gene expression from human airway epithelial cells (NCI-H292) were investigated. Confluent NCI-H292 cells were pretreated for 30 min in the presence of JGT and treated with ATP ($200{\mu}M$) or PMA ($10ng/ml$) or EGF ($25ng/ml$) or TNF-${\alpha}$ (0.2 nM) for 24 hrs to assess the effect of JGT both on ATP- or PMA- or EGF- or TNF-${\alpha}$-induced MUC5AC mucin production by using enzyme-linked immunosorbent assay (ELISA) and on gene expression by the same inducers using reverse transcription-polymerase chain reaction (RT-PCR). Results (1) JGT decreased the amount of intraepithelial mucosubstances of trachea of rats. (2) JGT did not show any renal and hepatic toxicities, and did not affect body weights either. (3) JGT significantly inhibited ATP-, PMA-, EGF-, and TNF-${\alpha}$-induced MUC5AC mucin productions from NCI-H292 cells. (4) JGT inhibited EGF-, and PMA-induced expression levels of MUC5AC gene in NCI-H292 cells. However, ATP- and TNF-${\alpha}$-induced MUC5AC gene expression levels were not affected in NCI-H292 cells. Conclusions The result from the present study suggests that JGT might control the production and gene expression of airway mucin observed in various respiratory diseases which accompanied by mucus hypersecretion. Also, JGT did not show liver toxicity or impact on kidney functions. The effect of JGT should be further studied by using animal experimental models which can show proper pathophysiology of airway diseases.