Decoction of heat-clearing, detoxifying and blood stasis removing relieves acute soft tissue injury via modulating miR-26b-5p/COX2 axis to inhibit inflammation

Traditional Chinese medicine (TCM), such as Huanglian-Jie-Du-Tang, a heat-clearing and detoxifying decoction is beneficial to alleviation of inflammation-related diseases. The objective of this study is to uncover the effect and mechanism of heat-clearing, detoxifying and blood stasis removing decoction (HDBD) on the treatment of acute soft tissue injury (STI) which is characterized with excessive inflammatory cascade at the onset. Male Sprague-Dawley (SD) rats with hammer beating served as the in vivo models of acute STI. Haematoxylin-eosin (HE) staining was used for histopathology assessment. The levels of inflammatory factors, including prostaglandin E2 (PGE2), tumor necrosis factor-αumTNF-α), interleukin (IL)-1t and IL-6 were measured by enzyme linked immunosorbent assay (ELISA). Human dermal microvascular endothelium cell line HMEC-1 and rat vascular endothelium cell line RAOEC were used to explore the mechanism in vitro. Luciferase gene reporter assay was applied to determine the relationship between miR-26b-5p and COX2. The results showed that HDBD intervention significantly reduced the temperature difference between the healthy side and affected side of rats with hammer beating, together with the decreased levels of COX2, PGE2, TNF-α, IL-6 and IL-1β, and the increased level of miR-26b-5p. In mechanism, miR-26b-5p targeted COX2 and decreased its expression, leading to significant decreases in the levels of PGE2, TNF-α and IL-6 in RAOEC and HMEC-1 cells. In addition, miR-26b-5p inhibition impaired the effects of HDBD on the suppression of PGE2, TNF-α, IL-6 and IL-1β in vitro. In conclusion, this study revealed that HDBD relieved acute STI via modulating miR-26b-5p/COX2 axis to inhibit inflammation.