The combination of cigarette smoke and solar rays causes effects similar to skin aging in a bilayer skin model

Ebeiedinone and peimisine inhibit cigarette smoke extract-induced oxidative stress injury and apoptosis in BEAS-2B cells

Ebeiedinone and peimisine are the major active ingredients of Fritillariae Cirrhosae Bulbus. In this study, we looked at how these two forms of isosteroidal alkaloids protect human bronchial epithelial BEAS-2B cells from oxidative stress and apoptosis caused by cigarette smoke extract (CSE). First, the cytotoxicity was determined using the CCK8 assay, and an oxidative stress model was established. Then the antioxidative stress activity and mechanism were investigated by ELISA, flow cytometry, and Western blotting. By the CCK-8 assay, exposure to CSE (20%, 40%, and 100%) reduced the viability of BEAB-2S cells. The flow cytometry findings indicated that CSE-induced production of ROS (0.5% to maximum) and treatments with 10 μM ebeiedinone and 20 μM peimisine attenuated the production of ROS. The western blot assay results indicate that ebeiedinone and peimisine reduce CSE-induced oxidative stress, DNA damage, apoptosis, and autophagy dysregulation by inhibiting ROS, upregulating SOD and GSH/GSSG, and downregulating MDA, 4-HNE, and 8-OHdG through the NRF2/KEAP1 and JNK/MAPK-dependent pathways, thereby delaying the pathological progression of COPD caused by CS.Our data suggest that CSE causes oxidative stress, DNA damage, and apoptosis in BEAS-2B cells, as well as the progression of COPD. Ebeiedinone and peimisine fight CS-induced COPD by suppressing autophagy deregulation and apoptosis.

Lipid Peroxidation as the Mechanism Underlying Polycyclic Aromatic Hydrocarbons and Sunlight Synergistic Toxicity in Dermal Fibroblasts

Light and atmospheric pollution are both independently implicated in cancer induction and premature aging. Evidence has been growing more recently on the toxic synergy between light and pollutants. Polycyclic aromatic hydrocarbons (PAHs) originate from the incomplete combustion of organic matter. Some PAHs, such as the Benzo[a]pyrene (BaP), absorb ultraviolet A (UVA) wavelengths and can act as exogenous chromophores, leading to synergistic toxicity through DNA damage and cytotoxicity concomitant to ROS formation. In this study, we shed light on the mechanism underlying the toxic synergy between PAHs and UVA. Using dermal fibroblasts co-exposed to UVA and BaP, we have demonstrated that the photosensitization reaction causes mortality, which is most likely caused by ROS accumulation. We have shown that these ROS are concentrated in the lipids, which causes an important induction of lipid peroxidation and malondialdehyde, by-products of lipid peroxidation. We have also shown the accumulation of bulky DNA damage, most likely generated by these by-products of lipid peroxidation. To our knowledge, this study represents the first one depicting the molecular effects of photo-pollution on dermal skin.