Hypertension causes many deaths worldwide and has shown an increasing trend as a severe non-communicable disease. Conventional antihypertensive drugs inevitably cause side effects, and great efforts have been made to exploit healthier and more-available substitutes. Microalgae have shown great potential in this regard and have been applied in the food and pharmaceutical industries. Some compounds in microalgae have been proven to have antihypertensive effects. Among these natural compounds, peptides from microalgae are promising angiotensin-converting enzyme (ACE) inhibitors because an increasing number of peptides show hypertensive effects and ACE inhibitory-like activity. In addition to acting as ACE inhibitors for the treatment of hypertension, these peptides have other probiotic properties, such as antioxidant and anti-inflammatory properties, that are important for the prevention and treatment of hypertension. Numerous studies have revealed the important bioactivities of ACE inhibitors and their mechanisms. This review discusses the antihypertensive effects, structure-activity relationships, molecular docking studies, interaction mechanisms, and other probiotic properties of microalgal ACE inhibitory peptides according to the current research related to microalgae as potential antihypertensive drugs. Possible research directions are proposed. This review contributes to a more comprehensive understanding of microalgal antihypertensive peptides.

In vertebrates, adrenocorticotropin (ACTH), released by the pituitary gland, is a critical part of the stress axis and stress response. Generally, the biosynthesis and secretion of ACTH are controlled by both hypothalamic stimulatory factors and inhibitory factors [eg, ACTH-releasing inhibitory factor (CRIF)], but the identity of this CRIF remains unrevealed. We characterized the neuropeptide B (NPB)/neuropeptide W (NPW) system in chickens and found that NPW could directly target the pituitary to inhibit growth hormone (GH) and prolactin (PRL) secretion via neuropeptide B/W receptor 2 (NPBWR2), which is completely different from the mechanism in mammals. The present study first carried out a series of assays to investigate the possibility that NPW acts as a physiological CRIF in chickens. The results showed that (1) NPW could inhibit ACTH synthesis and secretion by inhibiting the 3′,5′-cyclic adenosine 5′-monophosphate/protein kinase A signaling cascade in vitro and in vivo; (2) NPBWR2 was expressed abundantly in corticotrophs (ACTH-producing cells), which are located mainly in cephalic lobe of chicken pituitary, as demonstrated by single-cell RNA-sequencing, immunofluorescent staining, and fluorescence in situ hybridization; (3) dexamethasone could stimulate pituitary NPBWR2 and hypothalamic NPW expression in chicks, which was accompanied by the decease of POMC messenger RNA levels, as revealed by in vitro and subcutaneous injection assays; and (4) the temporal expression profiles of NPW-NPBWR2 pair in hypothalamus-pituitary axis and POMC in pituitary were almost unanimous in chicken. Collectively, these findings provide comprehensive evidence for the first time that NPW is a potent physiological CRIF in chickens that plays a core role in suppressing the activity of the stress axis.

(E)-Flavokawain A (FKA), the primary chalcone constituent of Piper methysticum, exhibits diverse pharmacological properties and holds significant potential for therapeutic development. Objectives: This study aims to investigate the anti-colorectal cancer effects and mechanisms of FKA. Methods: Using AOM/DSS-induced colorectal cancer models in C57 mice, the research examines the impact of different FKA doses, employing 16S rRNA and metabolomics to explore the potential mechanism. Results: The findings indicated that FKA significantly inhibited the progression of colorectal cancer in C57 mice by modulating the composition of the gut microbiota. This modulation involved the suppression of endotoxin secretion by pathogenic bacteria and the concurrent augmentation of beneficial bacteria. Furthermore, in the context of metabolic pathways, FKA regulates lipid metabolism and arachidonic acid metabolism, thereby mitigating the inflammatory transformation associated with colorectal cancer. Conclusions: These findings provide valuable insights supporting the potential of FKA as a viable preventive strategy against CRC.

Harmful algal blooms have occurred more frequently in recent decades and threaten aquaculture, tourism and human health. As a promising control method, most studies on allelopathic mechanisms have focused on the physiological effects on harmful algae. This study employed a multiomics approach to investigate the allelopathic response of the dinoflagellate Scrippsiella acuminata to the allelochemical protocatechuic acid, a phenolic compound known for its inhibitory effects on algal growth. Using transcriptomic, proteomic, and metabolomic analyses, we identified significant changes in gene expression (5247 upregulated and 81 downregulated), protein expression (56 upregulated and 49 downregulated), and metabolite profiles (320 upregulated and 168 downregulated) in response to allelochemical stress. Transcriptomic data revealed an upregulation of genes associated with antioxidant systems and energy metabolism, suggesting a potential antioxidant response to protocatechuic acid exposure. Proteomic analysis highlighted the impact on photosynthesis, energy metabolism, and genetic information processing, with a particular emphasis on the modulation of lipid and carbohydrate metabolism to adapt to stress. Metabolomic profiling corroborated these findings, demonstrating shifts in lipid and amino acid metabolism indicative of an adaptive strategy for energy storage and maintenance of cellular homeostasis under allelochemical stress. Notably, alterations in photosynthesis-related proteins and metabolites indicated a direct effect of protocatechuic acid on the photosynthetic machinery, potentially impairing algal growth and energy production. In conclusion, our multiomics analysis provides a comprehensive view of the complex response of S. acuminata to allelochemical stress, revealing the intricate interplay among genetic, proteomic, and metabolic adjustments. These insights contribute to the understanding of allelopathic interactions and offer potential avenues for the development of novel strategies to manage harmful algal blooms.