Objective To observe the effect of acupuncture preconditioning combined with PI3K blocker LY294002 on the expression of PI3K and Akt proteins and genes in the lung tissue and the contents of serum IL-12 and IL-13 in asthmatic rats

so as to explore its preprotective mechanism underlying improving asthma. Methods Sixty male Wistar rats were randomly divided into blank control

model

acupuncture pretreatment + blank

acupuncture pretreatment

acupuncture pretreatment + LY294002 and LY294002 groups(n=10 in each group). The asthma model was established by intraperitoneal injection of mixture solution of OVA and Al(OH)_3 and followed inhalation of 1%OVA for 30 min

once daily for 7 days. Rats of the blocker groups received inhalation of atomized LY294002 solution for 30 min before inhalation of 1% OVA

and acupuncture was applied to “Feishu”(BL13)

“Dazhui”(GV14) and “Fengmen”(BL12) for 20 min

once daily for 7 days before modeling. H.E. staining was used to assess histopathological changes of the lung tissue

and ELISA was used to detect the contents of serum IL-12 and IL-13. The immunoactivity of PI3K and Akt and expression of Akt mRNA of the lung tissue were detected by using immunohistochemistry and fluorescence quantitative real-time PCR

separately.Results Compared with the blank control group

the content of serum IL-12 was significantly decreased(P<0.01)

and the content of serum IL-13

the expression levels of PI3K

Akt protein and Akt mRNA were remarkably increased(P<0.01) in the model group. In comparison with the model group

the content of serum IL-12 in the pretreatment

pretreatment + LY294002 and LY294002 groups was significantly increased(P<0.01

P<0.05)

while the content of IL-13 and the expression levels of PI3K

Akt protein and Akt mRNA were considerably decreased(P<0.01

P<0.05) in the acupuncture pretreatment

acupuncture pretreatment+LY294002 and LY294002 groups. The therapeutic effect of acupuncture pretreatment+LY294002 was obviously superior to that of simple acupuncture pretreatment and LY294002(except PI3K and Akt in the LY294002 group) in up-regulating serum IL-12 level

and in down-regulating serum IL-13

and PI3K and Akt protein levels in the lung tissue(P<0.01). H.E. staining showed severe inflammatory factor infiltration in the bronchus and pulmonary interstitium

and obvious bronchial lumen narrowing with increased exudate in rats of the model group

which was relatively milder in rats of the acupuncture pretreatment

acupuncture pretreatment+LY294002 and LY294002 groups. There were no significant diffe-rences between blank control and pretreatment+blank groups in all of the above indicators(P>0.05). Conclusion Acupuncture preconditioning can inhibit airway inflammation in asthmatic rats

which may be associated with its functions in down-regulating the levels of pulmonary PI3K and Akt and serum IL-13 and up-regulating the content of serum IL-12. Acupuncture preconditioning combined with LY294002 has the best effect.