LAUSR

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 3h of ischemia followed by 6h of reperfusion, and extra intravenous Rg1 and pyrrolidine dithiocarbamate (Pro‐DTC), a selective inhibitor of nuclear factor kappa B (NF‐&kgr;B), 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‐&kgr;B p65 and cyclooxygenases‐2 (COX‐2) in lung tissue, and thromboxane B2 (TXB2) and 6‐keto‐ProstaglandinF1&agr; (6‐keto‐PGF1&agr;) 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‐PGF1&agr;/TXB2 ratio were increased, and NF‐&kgr;B 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‐&kgr;B/COX‐2 signaling pathway. HIGHLIGHTSGinsenoside Rg1 protects against limb ischemia reperfusion‐induced lung injury.Ginsenoside Rg1 attenuates inflammation via NF‐&kgr;B /COX‐2 signaling pathway.Ginsenoside Rg1 shares similar protective effects with the NF‐&kgr;B inhibitor.