Objective:To investigate the protective effect of naringenin on acute lung injury related with sepsis; To discuss its possible mechanism.Methods:Totally 30 male SD rats were randomly divided into sham-operation group, model group, naringin low-, medium- and high-dosage groups, with 6 rats in each group. The sepsis-related acute lung injury model was established by cecal ligation and puncture in all groups except the sham-operation group. After modeling, naringin low-, medium- and high-dosage groups were given naringin 20 mg/kg, 40 mg/kg and 80 mg/kg, respectively for gavage, while the sham-operation group and the model group were given the same volume of distilled water by gavage, once a day, for 2 days. Pathological changes in lung tissue were observed using HE staining. The levels of 1L-1, IL-6 and IL-18 in bronchoalveolar lavage fluid (BALF) were measured by ELISA; the expression of TNF-α in lung tissue was detected by immunofluorescence histopathology; the expressions of TGF-β1, TGF-βR1 and Smad2 were detected by Western Blot. An agonist group and a naringin plus agonist group were set up, with 6 mice in each group, and the expressions of TGF-β1 and Smad2 protein in the lung tissue of each group were detected by immunohistochemical staining to verify the effect of naringin on the expressions of TGF-β1 and Smad2 protein.Results:Compared with the model group, the pathological injury of lung tissue in naringin groups were obviously alleviated, and the levels of IL-1β, IL-6 and IL-18 in BALF decreased ( P<0.01), the protein expressions of TNF-α, TGF-β1, TGF-βR1 and Smad2 in lung tissue decreased ( P<0.01 or P<0.05). Further verification found that the expressions of TGF-β1 and Smad2 in the agonist group increased ( P<0.01), while the expressions of TGF-β1 and Smad2 in the naringin agonist group decreased ( P<0.01). Conclusion:Naringin can reduce the inflammatory response in the lung of the rats to protect against sepsis-related acute lung injury, and its protective effect could be related to the inhibition of the TGF-β1/Smad2 signaling pathway.

Metabolic reprogramming is a common phenomenon in cancer, with aerobic glycolysis being one of its important characteristics. Hypoxia-inducible factor-1α (HIF1Α) is thought to play an important role in aerobic glycolysis. Meanwhile, naringin is a natural flavanone glycoside derived from grapefruits and many other citrus fruits. In this work, we identified glycolytic genes related to HIF1Α by analyzing the colon cancer database. The analysis of extracellular acidification rate and cell function verified the regulatory effects of HIF1Α overexpression on glycolysis, and the proliferation and migration of colon cancer cells. Moreover, naringin was used as an inhibitor of colon cancer cells to illustrate its effect on HIF1Α function. The results showed that the HIF1Α and enolase 2 (ENO2) levels in colon cancer tissues were highly correlated, and their high expression indicated a poor prognosis for colon cancer patients. Mechanistically, HIF1Α directly binds to the DNA promoter region and upregulates the transcription of ENO2; ectopic expression of ENO2 increased aerobic glycolysis in colon cancer cells. Most importantly, we found that the appropriate concentration of naringin inhibited the transcriptional activity of HIF1Α, which in turn decreased aerobic glycolysis in colon cancer cells. Generally, naringin reduces glycolysis in colon cancer cells by reducing the transcriptional activity of HIF1Α and the proliferation and invasion of colon cancer cells. This study helps to elucidate the relationship between colon cancer progression and glucose metabolism, and demonstrates the efficacy of naringin in the treatment of colon cancer.
Glycolysis ; Colonic Neoplasms/metabolism* ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Phosphopyruvate Hydratase/metabolism* ; Flavanones/pharmacology* ; Cell Line, Tumor ; Databases, Genetic ; Cell Proliferation/drug effects* ; Transfection ; Warburg Effect, Oncologic