Elastin is a crucial component of the extracellular matrix that plays a significant role in maintaining skin elasticity and firmness. Within the dermis, elastin works in collaboration with collagen to form supportive structures that contribute to the overall health and appearance of the skin. As individuals age, the rate of elastin synthesis gradually declines, resulting in the degradation of skin elastic fibers, which subsequently leads to skin laxity and the formation of wrinkles. Furthermore, environmental factors, particularly ultraviolet radiation, can exacerbate the degradation of elastin and accelerate the aging process of the skin. Elasticity is regarded as a fundamental aspect of skin health; thus, maintaining adequate levels of elastin is essential for delaying the signs of skin aging and preserving the normal physiological functions of the skin. Currently, elastin has become an important ingredient in anti-aging products, demonstrating significant market potential and application prospects. This review focuses on the structural characteristics, physiological functions, and applications of elastin in cosmetics. Additionally, it discusses novel preparation techniques, future development opportunities, and challenges associated with elastin, with the objective of providing a robust theoretical framework for its application and advancement within the cosmetics industry.

Flavonoids are important plant metabolites that exhibit a wide range of physiological and pharmaceutical functions. Because of their wide biological activities, such as anti-inflammatory, antioxidant, antiaging and anticancer, they have been widely used in foods, nutraceutical and pharmaceuticals industries. Here, the hydroxylase complex HpaBC was selected for the efficient in vivo production of ortho-hydroxylated flavonoids. Several HpaBC expression vectors were constructed, and the corresponding products were successfully detected by feeding naringenin to vector-carrying strains. However, when HpaC was linked with an S-Tag on the C terminus, the enzyme activity was significantly affected. The optimal culture conditions were determined, including a substrate concentration of 80 mg·L⁻¹, an induction temperature of 28 °C, an M9 medium, and a substrate delay time of 6 h after IPTG induction. Finally, the efficiency of eriodictyol conversion from P2&3-carrying strains fed naringin was up to 57.67 ± 3.36%. The same strategy was used to produce catechin and caffeic acid, and the highest conversion efficiencies were 35.2 ± 3.14 and 32.93 ± 2.01%, respectively. In this paper, the catalytic activity of HpaBC on dihydrokaempferol and kaempferol was demonstrated for the first time. This study demonstrates a feasible method for efficiently synthesizing in vivo B-ring dihydroxylated flavonoids, such as catechins, flavanols, dihydroflavonols and flavonols, in a bacterial expression system.