This study aimed to investigate the preventive effects of the total polyphenols from Nymphaea candida (NCTP) on LPS-induced septic acute lung injury (ALI) in mice and its mechanisms. NCTP could significantly ameliorate LPS-induced lung tissue pathological injury in mice as well as lung wet/dry ratio and MPO activities (p < 0.05). NCTP could significantly decrease the blood leukocyte, neutrophil, monocyte, basophil, and eosinophil amounts and LPS contents in ALI mice compared with the model group (p < 0.05), improving lymphocyte amounts (p < 0.05). Moreover, compared with the model group, NCTP could decrease lung tissue TNF-α, IL-6, and IL-1β levels (p < 0.05) and downregulate the protein expression of TLR4, MyD88, TRAF6, IKKβ, IκB-α, p-IκB-α, NF-κB p65, p-NF-κB p65, NLRP3, ASC, and Caspase1 in lung tissues (p < 0.05). Furthermore, NCTP could inhibit ileum histopathological injuries, restoring the ileum tight junctions by increasing the expression of ZO-1 and occludin. Simultaneously, NCTP could reverse the gut microbiota disorder, restore the diversity of gut microbiota, increase the relative abundance of Clostridiales and Lachnospiraceae, and enhance the content of SCFAs (acetic acid, propionic acid, and butyric acid) in feces. These results suggested that NCTP has preventive effects on septic ALI, and its mechanism is related to the regulation of gut microbiota, SCFA metabolism, and the TLR-4/NF-κB and NLRP3 pathways.

Objectives: Isostrictiniin (ITN), a natural polyphenol extracted from Nymphaea candida (snow-white waterlily), has antioxidant and hepatoprotective activities that may be beneficial in treating metabolic dysfunction-associated steatotic liver disease (MASLD). This study aimed to investigate the protective effects of ITN on high-fat, high-sugar diet (HFSD)-induced steatosis in MASLD mice and its mechanisms. Methods: Kunming mice were randomly divided into normal control and HFSD groups. After being fed for 4 weeks, the HFSD group was randomly divided into model, atorvastatin calcium (ATC; 10 mg/kg), and ITN (25, 50, and 100 mg/kg) groups. After continued feeding for 4 weeks, the biochemical indexes in the mice were determined. Results: Compared with the model group, the liver index; FBG; HOMA-IR; serum AST, ALT, TG, TC, and LDL-C; and liver MDA, IL-6, TNF-α, and IL-1β levels in the ITN (25, 50, and 100 mg/kg) and ATC (10 mg/kg) groups were significantly decreased (p < 0.05), while serum HDL-C and liver SOD and GSH-Px levels were increased (p < 0.05). Pathological observation showed that ITN treatment mitigated the lipid liver deposition in the HFSD mice. Moreover, ITN could upregulate liver-tissue p-AMPK/AMPK protein expression in the HFSD-induced MASLD mice and downregulate SREBP-1c and ACC levels (p < 0.05). Conclusions: ITN can significantly improve MASLD mice, and its mechanism may be related to the regulation of the AMPK/SREBP-1c/ACC pathway.

This study aimed to investigate the preventive effects of isostrictiniin (ITN) from Nymphaea candida against acute lung injury (ALI) through lipopolysaccharide (LPS)-induced ALI mice and LPS-induced A549 cells. Compared with the model group, ITN (50 and 100 mg/kg) significantly reduced the lung indexes, W/D rates, BALF WBC counts, and total protein contents in ALI mice (p < 0.05), as well as the blood neu counts (p < 0.01), while increasing the blood lym counts (p < 0.01). ITN (50 and 100 mg/kg) also markedly decreased the lung tissue TNF-α, IL-6, IL-1β, MDA, and MPO activities in ALI mice (p < 0.01) and enhanced the SOD and GSH levels (p < 0.01). Additionally, ITN (50 and 100 mg/kg) significantly improved lung histopathological damage in ALI mice. Moreover, ITN (10 and 25 µM) significantly reduced the NO, PGE2, IL-1β, IL-6, TNF-α, and MDA levels in LPS-induced A549 cells (p < 0.01) while significantly increasing the SOD and GSH activities (p < 0.01). After LPS-induced A549 cells, the Keap1, p-JNK/JNK, p-ERK1/2/ERK1/2, p-P38/P38, p-IκBα/IκBα, and p-NF-κBp65/NF-κB p65 levels were significantly upregulated (p < 0.05), whereas the Nrf2 and HO-1 protein expressions were downregulated (p < 0.05). After treatment with ITN (25 μM), the changes in these relative protein expressions in LPS-induced A549 cells were significantly reversed (p < 0.05). The above results indicate that ITN has a better preventive effect against ALI, and its mechanisms are related to the regulation of the Keap1-Nrf2/HO-1 and MAPK/NF-κB signaling pathways.