Objective

2

To explore the effect of

Shujin Jianyao Pills

（舒筋健腰丸） on fibrosis of lumbar ligamentum flavum and the possible mechanism.

Methods

2

Thirty SD rats were randomly divided into normal group， model group， negative control group， positive control group and

Shujin Jianyao Pills

group， with six rats in each group. Lumbar instability injury method was used to establish rat models of ligamentum flavum fibrosis in all groups except the normal group. Seventy-two hours after the modeling， the

Shujin Jianyao Pills

group was given 1.5 g·kg

-

1

·d

-

1

of

Shujin Jianyao Pills

by intragastric administration， while the other groups were given 30 ml/kg

-

1

·d

-

1

of normal saline by intragastric administration， once a day for 8 weeks. Besides， in the negative control group and the positive control group， PBS liposomes （5 mg/ml， 0.5 ml） and clophosphate liposomes （5 mg/ml， 0.5 ml） were subcutaneously injected into the original incision respectively at once， 2 weeks， 4 weeks and 6 weeks after the modeling. The rat ligamentum flavum was evaluated histologically by Masson staining， and the collagen volume fraction （CVF） was calculated. Immunohistochemical staining was used to detect inducible nitric oxide synthase （iNOS）， tumor necrosis factor-alpha （TNF-α）， mouse growth factor-like phantom-containing mucus-like hormone-like receptor （F4/80） and transforming growth factor β

1

（TGF-β

1

） protein expression in ligamentum flavum. The expressions of F4/80 and TGF-β

1

， the markers of M2 macrophages in the ligamentum flavum， were detected by immunofluorescence double labeling.

Results

2

Compared to those in the normal group， the Masson staining of the model group， the negative control group and the

Shujin Jianyao Pills

group showed elastic fiber breakage and collagen accumulation， and the CVF， as well as the expression of iNOS， TNF-α， F4/80 and TGF-β

1

in the lumbar ligamentum flavum increased significantly （

P

＜0.01）. Compared to those in the model group， the collagen fibers in the positive control group and

Shujin Jianyao Pills

were reduced， while the cross-linking of collagen fibers and elastic fibers was loose， and the CVF was significantly reduced； the expressions of iNOS， TNF-α， F4/80 and TGF-β

1

in the lumbar ligamentum flavum were significantly reduced in the positive control group； the expression of iNOS in the

Shujin Jianyao Pills

group significantly increased， while TNF-α， F4/80 and TGF-β

1

expressions decreased （

P

＜0.05 or

P

＜0.01）. Compared to those in the positive control group， the

Shujin Jianyao Pills

group had more collagen fibers， significantly increased CVF， and significantly increased expressions of iNOS， TNF-α， F4/80 and TGF-β

1

in the lumbar ligamentum flavum （

P

＜0.05 or

P

＜ 0.01）. Immunofluorescence results showed that there was no expression of F4/80 and TGF-β

1

in the normal group and the positive control group. In the model group， F4/80 and TGF-β

1

were massively expressed and co-localized. The expression of F4/80 was higher in the

Shujin Jianyao Pills

group， but the expression of TGF-β

1

was less.

Conclusion

2

Shujin Jianyao Pills

can inhibit the progression of fibrosis of ligamentum flavum in rats， affect the M1/M2 polarization balance of macrophages in the fibrotic ligamentum flavum， shift the polarization to the M1， and inhibit M2 macrophage paracrine fibrosis key factor TGF-β

1

， thereby playing an anti-fibrosis role in the ligamentum flavum.