Objective To observe the effect of warm needling on the expression of oxidative stress related factors and pro-inflammatory factors in cartilage of mono sodium iodoacetate(MIA) induced knee osteoarthritis(KOA) model rats

so as to explore its mechanisms underlying improvement of KOA. Methods Sixty male Sprague Dawley rats were randomly divided into 5 groups: control

model

acupuncture

moxibustion

warm needling

with 12 rats in each group. Rats of the acupuncture

moxibustion

warm needling groups received manual acupuncture or moxibustion or both stimulation of “Zusanli”(ST36) for 15 minutes

once a day for 21 days beginning from the third day after modeling. The foot volume was measured by drainage method

and the plantar mechanical contraction reflex threshold(mechanical pain threshold

MPT) measured by using an electronic pain meter. After 21 days of treatment

the histopathological changes of knee joint were observed by HE staining

and Mankin score was calculated to evaluate the degree of cartilage destruction. The malondialdehyde(MDA) level was measured by colorimetry

and immunofluorescence staining was used to observe the expression of NOX2

SOD2 or IL-1β. Results Compared with the control group

the knee joint swelling volume from the 3

(rd)

day after modeling

Mankin score

MDA level

and the number of NOX2 and IL-1β positive cells were significantly increased(P

<

0.01

P

<

0.05)

while the MPT from the 3(rd) day after modeling

Mankin score

MDA level

and the number of NOX2 and IL-1β positive cells were significantly increased(P

<

0.01

P

<

0.05)

while the MPT from the 3

(rd)

day after modeling

and the number of SOD2 positive cells were considerably decreased(P

<

0.01) in the model group. After the interventions

the increased levels of the knee joint swelling volume from the 12(rd) day after modeling

and the number of SOD2 positive cells were considerably decreased(P

<

0.01) in the model group. After the interventions

the increased levels of the knee joint swelling volume from the 12

(th)

day after modeling

and the Mankin score

MDA level

NOX2 and IL-1β positive cells

and the levels of decreased MPT from the 9(th) day after modeling

and the Mankin score

MDA level

NOX2 and IL-1β positive cells

and the levels of decreased MPT from the 9

(th)

day after modeling and SOD2 positive cell number were reversed in the acupuncture

moxibustion

warm needling groups(P

<

0.05

P

<

0.01)

and the effects of warm needling were significantly superior to those of simple manual acupuncture and simple moxibustion in down-regulating knee joint volume

Mainkin score

MDA le-vel

and NOX2 and IL-1β positive cells

and in up-regulating MPT from the 12(th) day after modeling and SOD2 positive cell number were reversed in the acupuncture

moxibustion

warm needling groups(P

<

0.05

P

<

0.01)

and the effects of warm needling were significantly superior to those of simple manual acupuncture and simple moxibustion in down-regulating knee joint volume

Mainkin score

MDA le-vel

and NOX2 and IL-1β positive cells

and in up-regulating MPT from the 12

(th)

day after modeling

and the number of SOD2 positive cells(P

<

0.05). No significant differences were found between the acupuncture and moxibustion groups in the levels of all the indexes mentioned above(P

>

0.05). HE staining showed rough and damaged articular surface

with subchondral neovascularization and moderate connective tissue hyperplasia

and abundant lymphocyte and monocyte infiltration in the model group

which was milder in the acupuncture

moxibustion groups particularly in the warm needling group after 21 days' interventions. Conclusion Warm needling can relieve knee joint pain

swelling and inflammatory damage in KOA rats

which may be associated with its function in inhibiting oxidative stress and inflammation in the cartilage of KOA. The therapeutic effect of warm needling is better than that of manual acupuncture and moxibustion alone.