Mailuoning oral liquid ameliorates vasculitis in thromboangiitis obliterans rats via inactivating cGAS-STING-IRF3 and TLR4-MAPKs/NF-κB signaling pathways

Ethnopharmacological relevance: Mailuoning oral liquid (MLN O), one traditional Chinese patent medicine, has a good therapeutic effect on thromboangiitis obliterans (TAO) in clinical practice. However, the underlying mechanism remains unclear.

Aim of the study: This study aimed to explore the effects and potential mechanisms of MLN O against TAO based on network pharmacology and experimental verification.

Materials and methods: Network pharmacology was used to identify the intersectional targets and signaling pathways of MLN O and TAO. In vivo, the TAO model was established by injecting sodium laurate and dihydrotestosterone (DHT) into the femoral arteries of Wistar rats. Rats were given the indicated drugs by intragastric administration (i.g.), intravenous injection (i.v.), or subcutaneous injection (s.c.) per day for 21 days since a week before surgery. In vitro, HUVECs, RAW264.7, and THP-1 cells were stimulated by LPS and DHT to simulate the pathological changes of TAO. The anti-inflammatory, anticoagulant, and immunomodulatory effects of MLN O were evaluated by histological observation, blood biochemical indexes detection, H&E staining, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), qRT-PCR, western blotting and immunofluorescence assays. Furthermore, the vascular ring test was applied to explore the vasodilatory activity of MLN O.

Results: MLN O significantly improved the pathological signs in TAO rats through its excellent anti-inflammatory, anticoagulant, immunomodulatory, and vasodilatory effects. Specifically, MLN O alleviated the gangrene and reduced the thrombosis in TAO rats, meanwhile, suppressed the expressions of inflammatory factors and clotting factors, which is related to the inactivations of cGAS-STING-IRF3 and TLR4-MAPKs/NF-κB signaling pathways. However, the superphysiological dose of DHT deteriorated the pathological development of TAO in vitro and in vivo. Moreover, the results of network pharmacology are consistent with the experimental verification.

Conclusion: Collectively, this study indicates for the first time that MLN O could alleviate TAO by inhibiting cGAS-STING-IRF3 and TLR4-MAPKs/NF-κB signaling pathways, which sheds LIGHT on a novel clinical therapeutic strategy for TAO.

Dihydrotestosterone; Mailuoning oral liquid; Network pharmacology; TLR4-MAPKs/NF-κB; Thromboangiitis obliterans; cGAS-STING-IRF3.