Table 2.
Main anti-photoaging effects of flavonols in different study models.
| Flavonols | Model/UV Radiation | Activities | Ref. |
|---|---|---|---|
| Quercetin, myricetin, and kaempferol | HDFs/UVA | All flavonoids inhibit MMP-1 mRNA levels; presents antioxidant activity | [50] |
| Galangin, kaempferol and quercetin | EpiDermTM/UVA or UVB | All flavonoids reduce MMP-1 and TNF-α secretion; pretreatment reduces the cyclobutane thymine dimers in UVB-irradiation | [70] |
| Myricetin | PHKC/UVB | Decreases MDA level; suppresses H2O2 production and JNK activation | [71] |
| Hairless mice/UVB | Decreases epidermal thickening; inhibits enzyme activity and MMP-9 protein expression; inhibits Raf kinase activity and, consequently, decreases MEK and ERK phosphorylation | [72] | |
| Quercetin and Quercetin nanoparticles | HaCaT cells/UVB | Both decrease NF-κB protein; suppress the IkB-α phosphorylation; reduce the COX-2 protein expression level | [74] |
| C57BL/6 mice/UVB | Decreases IkB-α phosphorylation, COX-2 expression, and PGE2 concentration | ||
| Quercetin | PHKC/UVA and UVB | Reduces NF-κB DNA-binding; inhibits TNF-α, IL-1β, IL-6, and IL-8 expression | [75] |
| Human abdominal skin tissue/UVA and UVB | Inhibits COX-2, MMP-1, and collagen degradation; suppresses NF-κB and AP-1 activation, and JAK2 and PKCδ kinase activity; decreases the Akt, JNK, ERK, and STAT3 phosphorylation | [37] | |
| Hairless mice/UVB | Decreases MPO activity, increases GSH, and suppresses proteinases secretion/activity | [76] | |
| Quercitrin | JB6 cells/UVB | Suppresses apoptosis; reduces C-caspase-3 and C-PARP1 activation; decreases NF-κB activation, DNA damage, 8-OHdG production, γ-H2AX expression, and superoxide radical production; inhibits hydroxyl radical and hydrogen peroxide productions; increases SOD and CAT expressions | [77] |
| Hairless mice/UVB | Decreases apoptosis, C-caspase-3 and C-PARP1 expression; DNA damage; 8-OHdG production; and γ-H2AX expression; increases XPA, SOD and CAT expression and GSH levels | ||
| Fisetin | HDFs/UVB | Inhibits collagen degradation, MMP-9, MMP-3, and MMP-1 expression, COX-2, NO generation, the PGE2 and intracellular ROS, NF-κB translocation into the nucleus and the CREB phosphorylation level; decreases JNK and ERK expression, p38 phosphorylation, and IκB degradation | [81] |