Yih-Fung Chen

The aryl hydrocarbon receptor (AhR) is highly expressed in keratinocytes and functions as an environmental sensor regulating xenobiotic metabolism, epidermal differentiation, and inflammatory responses. Particulate matter (PM), a major environmental pollutant containing reactive oxygen species (ROS), transition metals, and polycyclic aromatic hydrocarbons (PAHs), induces oxidative stress and inflammation, leading to skin barrier dysfunction. Transition metals generate ROS via Fenton-type reactions, whereas PAHs undergo AhR-mediated metabolism that further amplifies oxidative stress. Excessive ROS promotes inflammatory cytokine expression and disrupts barrier-related protein expression. In response, activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway induces antioxidant enzymes, including heme oxygenase-1 (HO-1), to counteract oxidative damage. However, sustained PM exposure may overwhelm these defense mechanisms, resulting in impaired cellular homeostasis. Although the roles of AhR and Nrf2 have been extensively investigated individually, their coordinated regulation in PM-induced skin injury remains underexplored. This review summarizes current evidence on the functional interplay between AhR and Nrf2 and discusses how coordinated activation of these pathways integrates xenobiotic metabolism, antioxidant defense, and barrier-associated functions. Overall, the available evidence supports a dual-pathway framework for maintaining epidermal homeostasis under PM-induced environmental stress.

FBMN-guided isolation of Atriplex maximowicziana led to eight new and thirteen known compounds. Two new compounds showed anti-colorectal cancer activity.

Two novel alkaloids, zoanides A and B (1 and 2), 12 new zoanthamine-type alkaloids (3-14), together with two known compounds (15 and 16) were obtained from the zoantharian Zoanthus vietnamensis. Their structures and absolute configurations were established by extensive spectroscopic data, DP4+ probability calculation, and X-ray crystallographic analyses. Structurally, compound 1 represents an unusual functionalized skeleton caused by oxidative cleavage; compound 2 possesses an unprecedented 6/6/5/6/7-fused pentacyclic carbon skeleton. Additionally, the plausible biosynthetic pathways of 1 and 2 were proposed. All isolates were evaluated in vitro for neuroprotection. Among them, compounds 2, 3, 8, 9, and 15 exhibited neuroprotection against paclitaxel-induced neurite damage without interfering with the anticancer effects of paclitaxel. Moreover, compounds 2 and 9 demonstrated moderate protective effects against oxaliplatin-induced oxidative stress overload without interfering with the anticancer effects of oxaliplatin.