Objective To study the effect of moxa-smoke inhaling on the respiratory system

so as to provide experimental data and theoretical basis for evaluating the safety of moxa-smoke inhaling during moxibustion treatment.Methods A total of 48 SD rats were randomized into control

low

medium and high moxa-smoke-concentration groups(n=12 in each group).The low

medium and high concentrations of smoke were controlled in(0.11±0.05)mg/m3

(0.23±0.05)mg/m3 and(0.53±0.05)mg/m3 respectively in each of 3 glass boxes(with reference to the level of PM 2.5).The smoking was conducted 4 hours each time

twice a day for 100 days.The normal group did not receive any moxa-smoke inhaling.The histopathological changes of lung and bronchial tissues were detected by H.E.stainning

and the contents of TNF-αand IL-1βof plasma

bronchoalveolar lavage fluid(BALF)and lung tissue detected by ELISA.The levels of forced vital capacity(FVC)

forced expiratory volume(FEV)

FEV 0.3/FVC(0.3=the 0.3 rd second)

maximal mid-expiratory flow rate(MMEF)

peak expiratory flow(PEF)were detected by animal pulmonary function analysis system.Results After 100 days' moxa-smoke inhaling

the contents of TNF-αin the plasma

BALF and lung tissues and IL-1βin the lung tissue of the low

medium and high concentration moxa-smoke groups

and IL-1βin the plasma and BALF of the medium and high concentration groups were significantly increased relevant to the control group(P<0.05

P<0.01).H.E.stain showed various inflammatory changes in the lungs and trachea tissues

including obvious fusion of pulmonary alveoli

lymphocyte infiltration

increase of capillary permeability

red blood cell exudation

etc.in the high concentration group

these situations were milder in the medium concentration group and were not obvious in the low concentration group.Compared with the control group

there were no significant changes in the FVC

FEV

FEV 0.3/FVC

MMEF and PEF of lung function in the three concentration groups(P> 0.05).Conclusion Long term inhalation of high concentration of moxa-smoke may lead to inflammatory injury in the lung and bronchial tissues but has no significant effect on the respiratory function in rats.Nevertheless

agood air-ventilation during moxibustion in a treatment room is necessary.