Background/Objectives: At present, a large number of bioactive peptides have been found from plant sources with potential applications for the prevention of chronic diseases. By promoting plant-derived bioactive peptides (PDBPs), we can reduce dependence on animals, reduce greenhouse gas emissions, and protect the ecological environment. Methods: In this review, we summarize recent advances in sustainably sourced PDBPs in terms of preparation methods, biological activity, structure–activity relationships, and their use in chronic diseases. Results: Firstly, the current preparation methods of PDBPs were summarized, and the advantages and disadvantages of enzymatic method and microbial fermentation method were introduced. Secondly, the biological activities of PDBPs that have been explored are summarized, including antioxidant, antibacterial, anticancer and antihypertensive activities. Finally, based on the biological activity, the structure–activity relationship of PDBPs and its application in chronic diseases were discussed. All these provide the foundation for the development of PDBPs. However, the study of PDBPs still has some limitations. Conclusions: Overall, PDBPs is a good candidate for the prevention and treatment of chronic diseases in humans. This work provides important information for exploring the source of PDBPs, optimizing its biological activity, and accurately designing functional foods or drugs.

In order to obtain homogeneous Sanghuangporus vaninii polysaccharides with antioxidant and anti-inflammatory activities, a response surface method (RSM) was used to compare the polysaccharide extraction rate of hot water extraction and ultrasonic-assisted extraction from Sanghuangporus vaninii. The optimal conditions for ultrasonic-assisted extraction were determined as follows: an extraction temperature of 60 °C, an extraction time of 60 min, a solid–liquid ratio of 40 g/mL, and an ultrasonic power of 70 W. An SVP (Sanghuangporus vaninii polysaccharides) extraction rate of 1.41% was achieved. Five homogeneous monosaccharides were obtained by gradient ethanol precipitation with diethylaminoethyl–cellulose (DEAE) and SephadexG-100 separation and purification. The five polysaccharides were characterized by high performance liquid chromatography, the ultraviolet spectrum, the Fourier transform infrared spectrum, TG (thermogravimetric analysis), the Zeta potential, and SEM (scanning electron microscopy). The five polysaccharides had certain levels of antioxidant activity in vitro. In addition, we the investigated the anti-inflammatory effects of polysaccharides derived from Sanghuangporus vaninii on lipopolysaccharide (LPS)-induced RAW 264.7 cells and Kupffer cells. Further, we found that SVP-60 significantly inhibited the levels of pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in lipopolysaccharide (LPS)-induced RAW 264.7 cells and promoted the level of the anti-inflammatory cytokine IL-10 in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Our study provides theoretical support for the potential application of Sanghuangporus vaninii in the field of antioxidant and anti-inflammatory activities in vitro.

Inflammation assumes a vital role in the pathogenesis of depression and in antidepressant treatment. Paeoniflorin (PF), a monoterpene glycoside analog possessing anti-inflammatory attributes, exhibits therapeutic efficacy on depression-like behavior in mice. The objective of this study was to evaluate the antidepressant effects of PF on depression elicited by the chronic unpredictable mild stress (CUMS) model and the precise neural sequence associated with the inflammatory process. In this study, we established an in vivo mouse model induced by CUMS and an in vitro BV2 cell model induced by LPS+ATP. The mechanism of PF for depression was assessed by the SIRT1 selective inhibitor EX-527. The findings demonstrated that PF significantly alleviated the damage of BV2 cells treated with LPS and ATP, inhibited the generation of ROS, up-regulated the expression of SIRT1 mRNA, and down-regulated the expression of nuclear NF-κB, p65, NLRP3, Caspase-1 and GSDMD-N in vitro. In vivo, PF mitigated the depressive-like behavior induced by CUMS, reduced the number of neurons, and decreased the secretion of pro-inflammatory factors IL-1β, IL-6, and TNF-α in the hippocampus. Immunohistochemical results indicated that PF attenuated CUMS-induced hyperactivation of microglia. Moreover, the expression level of SIRT1 in the hippocampus was augmented, while the protein levels of NF-κB, p65, NLRP3, Caspase-1, IL-1β and GSDMD-N were diminished after PF treatment. Additionally, the selective inhibition of SIRT1 attenuated the therapeutic effect of PF on depression. These results imply that PF possesses antidepressant properties that rely on SIRT1 signaling to regulate NLRP3 inflammasome inactivation.