Phlorotannins are among the most important defensive molecules in kelp. They have been majorly identified in brown algae so far. Type III polyketide synthase (PKS) is regarded as one of the enzymes catalyzing a major step in the biosynthetic pathway of phlorotannins. In this study, a type III PKS gene ( sjPKS1 ) is characterized from the economic brown alga Saccharina japonica sporophyte. It contains 7 exons and 6 introns. The sjPKS1 open reading frame consists of 1245 nucleotides encoding a protein of 414 amino acids. The sjPKS1 are 87%, 83%, and 82% identical to that of Ectocarpus siliculosus , Sargassum binderi , and Sargassum fusiforme at the nucleotide level, respectively. While the amino acid sequences of sjPKS1 share more than 90% identity to that of the three brown algae species. The sjPKS1 expression at 200 µmol photons m −2 s −1 was significantly higher than at 20 and 50 µmol photons m −2 s −1 in sporophytic seedlings, so did the content of soluble phlorotannins inside the plants. Seven motifs in response to light are identified in the 5′ flanking region of sjPKS1 and two potential transcription factors are predicted by screening yeast one-hybrid library.
Phlorotannins, polyphenolic compounds that exist only in brown algae, have an effect on T2DM. However, the structure of phlorotannins is complex and diverse, and the complex role of therapeutic targets and active compounds has not been revealed. In this study, the potential targets and pharmacological effects of phlorotannins in the treatment of T2DM were identified based on network pharmacology and enzyme activity inhibition experiment. In total, 15 phlorotannins and 53 associated targets were yielded. Among them, SRC, ESR1, AKT1, HSP90AB1, and AR were defined as core targets. 527 GO biological processes items and 101 KEGG pathways were obtained, including EGFR tyrosine kinase inhibitor resistance, thyroid hormone signaling pathway, AGE-RAGE signaling pathway in diabetic complications, and VEGF signaling pathway. Phlorotannins could enable resistance against T2DM by inflammatory, survival, gene transcription, proliferation, apoptosis, and atherosclerosis. Finally, α-glucosidase inhibition assay and molecular docking proved the effect of selected phlorotannins on T2DM. Practical applications Phlorotannins are a kind of polyphenol compounds that only exists in brown algae. Its structure is polymerized by aromatic precursors phloroglucinol (1,3,5-trihydroxybenzene). They have aroused great interest due to their excellent and valuable biological activities. However, the structure of phlorotannins is complex and diverse, and the complex role of therapeutic targets and active compounds has not been revealed. In this study, the potential targets and pharmacological effects of phlorotannins in the treatment of T2DM were determined basis on network pharmacology and enzyme activity inhibition experiment. In conclusion, the results showed the value of phlorotannins treating on T2DM. Moreover, this study has great significance for improving the medicinal value of phlorotannins and screening natural products for the treatment of T2DM.
Fengxian Luo,Beiwei Zhu,Di Wu,Yu Xu,Tao Chen,Yanfei Li,Jiangning Hu
Acute liver injury (ALI) is a severe health condition with limited treatment options. Phlorotannin (PT), a natural compound extracted from seaweeds, has shown potential in improving liver function. However, its poor stability and bioavailability have limited its applications in vivo. In this study, we developed PT-based nanoparticles (NPs) through a Mannich reaction with glycine, which exhibited good biocompatibility and prolonged circulation time in vivo. Our results revealed that the PT NPs possess strong free radical scavenging ability, effectively reducing reactive oxygen species (ROS) and alleviating oxidative stress and proinflammatory responses in the H2O2-induced oxidative damage model of HepG2 cells. Furthermore, the PT NPs effectively attenuated oxidative stress and inflammation in the liver tissue of carbon tetrachloride (CCl4)-induced liver injury mice by regulating the Nrf2/HO-1 signaling pathway. In summary, our results suggested that the PT NPs could serve as a promising nano-therapeutic strategy for alleviating ALI.
危险品化学品经营许可证（带存储）