Zhong Wang

Hydroxytyrosol (HT), a potent phenolic compound derived from olives, has attracted significant attention due to its exceptional antioxidant, anti-inflammatory, and antimicrobial properties. This review comprehensively examines recent advances in the synthesis, biological functions, safety profiles, and legal regulations of HT. We discuss both natural and biotechnological synthesis routes, including enzyme-mediated, non-transgenic, and transgenic biosynthetic methods, highlighting recent innovations that have improved yield and purity. The review further explores the multifaceted biological activities of HT, ranging from its role in cardiovascular protection and neuroprotection to its anticancer and metabolic regulatory effects. Safety assessments from animal and human studies are analyzed, demonstrating low toxicity and favorable metabolic profiles at physiologically relevant doses. Additionally, we compare international regulatory frameworks from the United States, China, and the European Union, which underscore the compound’s safe use in food, pharmaceuticals, and cosmetics. Finally, the review outlines future research directions aimed at optimizing production methods, enhancing bioavailability, and addressing long-term toxicological outcomes, thereby reinforcing HT’s potential as a high-value functional ingredient in various industries.

Ergothioneine (EGT), a natural thiol compound with potent antioxidant properties, exhibits diverse biological functions, including anti-inflammatory, neuroprotective, and cardioprotective effects. Despite its promising health and food applications, current production methods, such as mushroom-based liquid fermentation, are hindered by low yields and complex processes. Advances in biosynthetic fermentation, including heterologous expression of key pathway genes and optimization of cultivation conditions, offer promising solutions to these challenges. Recent discoveries, such as the catalytic efficiency of mononuclear non-heme iron enzymes like Egt1 and EgtB, have streamlined EGT biosynthetic pathways, reducing steps and increasing yield. The compound’s active transport via the OCTN1 protein facilitates its distribution across tissues, enhancing its therapeutic efficacy and potential in functional foods. Currently employed as an antioxidant and antimelanogenic agent in aquatic products, EGT holds vast potential for broader applications in food systems. This review explores the advancements in EGT production and biosynthesis while emphasizing its prospects as a safe, versatile, and effective natural ingredient for health and industrial applications.

β-Hydroxy-β-methylbutyrate (HMB), a metabolite of the essential amino acid leucine, is acknowledged for its powerful role in facilitating muscle protein synthesis, reducing muscle catabolism, and promoting fat-free mass accumulation. With well-documented anticatabolic, anabolic, and lipolytic effects, HMB has been extensively studied in clinical settings and has exhibited potential in mitigating muscle loss induced by aging, cancer cachexia, and sarcopenia. Moreover, HMB finds applications in specialized medical nutrition, sports nutrition, and animal husbandry, with recent research illustrating its benefits in enhancing animal growth and immunity. This review highlights the current understanding of HMB’s physiological mechanisms, its diverse applications, and recent advancements in detection methods such as High-Performance Liquid Chromatography (HPLC), Gas Chromatography (GC), and Liquid Chromatography–Mass Spectrometry (LC–MS). Additionally, it discusses the future prospects of HMB bio-manufacturing. The establishment of standardized guidelines for its safe use and testing is crucial for its broader adoption in the food industry. Future research should focus on further elucidating HMB’s muscle growth mechanisms and broadening its applications across the food, health, and agricultural sectors. In sum, future studies should prioritize mechanistic exploration, safety and synergy, along with standardization to fully harness HMB’s potential.

Inflammatory bowel disease (IBD) is a chronic disease influenced by a complex interplay of factors, including genetics, environmental, and gut microbiota. This study aimed to explore the therapeutic potential of the natural polyphenolic compound hydroxytyrosol (HT) in modulating dextran sodium sulfate (DSS)-induced colitis in mice. The findings demonstrate that oral administration of HT significantly alleviated colitis symptoms, as evidenced by a reduction in the disease activity index and improvements in colonic pathology. HT was found to inhibit the release of pro-inflammatory cytokines, enhance antioxidant status, and mitigate oxidative stress. Furthermore, HT contributed to the restoration of the gut barrier by reinstating tight junction proteins, reducing the inflammatory marker lipopolysaccharide (LPS), and suppressing inflammation-related genes. This compound also modulated the NLRP3-Cas-1-GSDMD-IL-1β inflammatory pathway and inhibited the NF-κB (nuclear factor kappa B) pathway, thereby alleviating colitis. Gut microbial analysis revealed that HT enriched the abundance of Bacteroidota and altered the balance between Bacteroidota and Firmicutes in mice. Correlation analysis between bacterial microbiota and inflammatory factors suggested that HT may alleviate colitis by modulating the relative abundance of Alistipes, Bacteroides, and unclassified_f__Muribaculaceae. These findings underscore the potential of HT as a therapeutic agent in the treatment of colitis.