ABSTRACT
The aim of the present research is to investigate anti-UVB radiation activity of total flavonoids from Ilex latifolia Thunb. (namely large-leaved Kuding tea) on human keratinocyte cell line (HaCaT cells) based on network pharmacology and molecular docking technique. Network pharmacology was used to screen target genes of active ingredients from Ilex latifolia Thunb. associated with UVB irradiation. The possible signaling pathways were analyzed by KEGG enrichment and verified by cellular experiments. Molecular docking was used to assess the affinity between the active ingredients and the core targets. The prediction of network pharmacology and molecular docking was identified by series experiment in UVB-irradiated HaCaT cells. Network pharmacology results showed that the active ingredients of Ilex latifolia Thunb. for anti-UVB irradiation were mainly flavonoids, and the possible signaling pathways were involved in PI3K-AKT, apoptosis, MAPKs, NF-κB, and JAK-STAT3. Molecular docking indicated key binding activity between AKT1-Glycitein, STAT3-Formononetin, CASP3-Formononetin, TNF-Kaempferol, CASP3-Luteolin, and AKT1-Quercetin. The total flavonoid pretreatment (0.25-1.0 mg/mL) down-regulated the expression of IL-6, IL-1ß, and TNF-α in the cells determined by ELISA. The expression of phosphor PI3K, phosphor AKT, phosphor JAK, phosphor STAT3, phosphor JNK, and phosphor p38 MAPKs and COX-2 proteins in cytosolic and NF-κB p65 protein in nucleus were down-regulated and determined by western blot. It also protected UVB-irradiated cells from apoptosis by reducing apoptosis rate and down-regulating active-caspase 3. In a word, the total flavonoid treatment protected HaCaT cells from UVB injuries effectively, and the potential mechanism involves PI3K-AKT, JAK-STAT3, MAPK, and NF-κB pathway by anti-inflammatory and apoptosis action in cells. The mechanism in vivo experiment needs to be further confirmed in future.
ABSTRACT
Natural products are favored in the study of skin photodamage protection recently. Isoquercetin, namely 3-O-glucoside of quercetin, can be isolated from various plant species. In present research, the protective effect of isoquercitrin on UVB-induced injury in cells and mice skin were investigated. Our study reveals that 400 µM of isoquercitrin exhibits the best viability on UVB-irradiated HaCaT cells, and beneficial effects against oxidative stress UVB-induced in skin tissue by decreasing the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), and simultaneously enhancing the activity of superoxide dismutase (SOD). Additionally, isoquercitrin was identified as an anti-inflammatory agent by reducing the level of COX-2 by Western blot analysis, and inflammatory cytokines such as IL-6, IL-1ß, and TNF-α by ELISA, and UVB-induced epidermal thickening evidenced by H&E staining. It also effectively prevented UVB-induced collagen fibers from degradation identified by Masson staining. Isoquercitrin significantly inhibited MAPK pathway by downregulating the levels of AP-1, MMP-1, MMP-3, phospho-p38, phospho-JNK, phospho-ERK, cleaved caspase-9, cleaved caspase-3, and JAK2-STAT3 pathway by western blot analysis. In conclusion, isoquercitrin pretreatment protected mice skin from UVB irradiation-induced injury effectively, and the underlying mechanism may involve MAPK and JAK2-STAT3 signaling pathways.
ABSTRACT
Introducing a second component is an effective way to manipulate polymerization behavior. However, this phenomenon has rarely been observed in colloidal systems, such as polymeric nanoparticles. Here, we report the supramolecular polymerization of polymeric nanorods mediated by block copolymers. Experimental observations and simulation results illustrate that block copolymers surround the polymeric nanorods and mainly concentrate around the two ends, leaving the hydrophobic side regions exposed. These polymeric nanorods connect in a side-by-side manner through hydrophobic interactions to form bundles. As polymerization progresses, the block copolymers gradually deposit onto the bundles and finally assemble into helical nanopatterns on the outermost surface, which terminates the polymerization. It is anticipated that this work could offer inspiration for a general strategy of controllable supramolecular polymerization.
