Fisetin quarterhydrate, a natural flavonol present in numerous fruits and vegetables, exhibits benefits including antioxidant, anticancer, and neuroprotective effects.

Fisetin quarterhydrate suppresses lipid accumulation and diminishes the expression of PPARγ in 3T3-L1 cells. It inhibits the early stages of preadipocyte differentiation and induces the expression of Sirt1, further promoting Sirt1-mediated deacetylation of PPARγ and FoxO1, enhancing the binding of Sirt1 to the PPARγ promoter and repressing PPARγ transcriptional activity, thereby inhibiting adipogenesis [1]. Fisetin quarterhydrate binds to tubulin, stabilizing microtubules more effectively than paclitaxel. In human prostate cancer cells, fisetin quarterhydrate treatment causes a pronounced upregulation of microtubule-associated proteins (MAP)-2 and -4, significantly inhibiting PCa cell proliferation, migration, and invasion. Nudc, a protein associated with microtubule motor dynein/dynactin complex regulating microtubule dynamics, is also downregulated with fisetin quarterhydrate treatment [2].

Treatment with Fisetin quarterhydrate in mice exposed to UVB reduces proliferation and decreases the infiltration of inflammatory cells. This treatment also lowers levels of inflammatory mediators, such as COX-2, PGE2 and its receptors (EP1-EP4), and MPO activity. Moreover, Fisetin quarterhydrate reduces levels of pro-inflammatory cytokines, including TNFα, IL-1β, and IL-6, in UVB-exposed skin. Additionally, this treatment diminishes markers of cellular proliferation and DNA damage, as evidenced by the increased expression of the proteins p53 and p21 [3].