Ginsenoside Rg1 protects against hind-limb ischemia reperfusion induced lung injury via NF-κB/COX-2 signaling pathway.

BACKGROUND/AIMS: Ginsenoside Rg1 is regarded as the primary bioactive ingredient in Panax notoginseng that has been well recognized for its protective effects against ischemia/reperfusion (IR) injury. However, the mechanisms still remain elusive. Our study aims to investigate the effects of Rg1 against lung injury induced by hind-limb IR in rats.

METHODS

Twenty-four Sprague Dawley rats were randomly submitted to sham operation (SM group), hind-limb IR (IR group), hind-limb IR + Rg1 (Rg1 group), and hind-limb IR + Pro-DTC group (PD group). All the rats except those in SM group were subjected to 3 h of ischemia followed by 6 h of reperfusion, and extra intravenous Rg1 and pyrrolidine dithiocarbamate (Pro-DTC), a selective inhibitor of nuclear factor kappa B (NF-κB), was administered intravenously before ischemia in the Rg1 and PD group, respectively. The activities of myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT), as well as protein expressions of NF-κB p65 and cyclooxygenases-2 (COX-2) in lung tissue, and thromboxane B2 (TXB2) and 6-keto-ProstaglandinF (6-keto-PGF) levels in bronchoalveolar lavage (BAL) fluid were detected. Morphological changes, index of quantitative assessment of histologic lung injury (IQA), apoptosis index (AI) and lung Wet/Dry ratio were also evaluated.

RESULTS

The levels of Wet/Dry ratio, IQA, AI, activities of MPO and 6-keto-PGF/TXB ratio were increased, and NF-κB p65 and COX-2 protein expression were upregulated, while SOD and CAT levels were decreased in lung tissue in IR group as compared with SM group (p < 0.05), all the alterations could be significantly reversed by Rg1 or Pro-DTC pretreatment (p < 0.05). And Rg1 and Pro-DTC also significantly attenuated the pulmonary histological abnormalities induced by IR.

CONCLUSION

Ginsenoside Rg1 potentially attenuated lung injury induced by hind-limb IR by regulating NF-κB/COX-2 signaling pathway.