fisetin: one bounded, context-dependent signal across receipts

Source literature boundary memo

Research question

Across retrieved fact-level receipts for fisetin, which endpoints show directionally favorable versus null/non-convergent signals, and what matched PICO remains untested?

Selection criteria

The source-literature fallback selected fisetin because the domain snapshot exposed enough fact-backed, topic-overlapping papers. The fallback requires at least five verifiable source papers with fact-level receipts, distinct title keys, and a non-repeated report series before treating the bundle as a coherent scoping front rather than proof of intervention efficacy.

Boundary map

• Intermittent supplementation with fisetin improves arterial function in old mice by decreasing cellular senescence [primary; 2023] doi:10.1111/acel.14060
  • Finding: IC50 of fisetin 3.4 ± 0.3 μM on senescent cells versus 7.0 ± 0.4 μM on control cells
  • Population: senescent human umbilical vein endothelial cells (HUVECs)
  • Intervention/exposure: fisetin
  • Comparator: nonsenescent control HUVECs (IC50 7.0 ± 0.4 μM)
• Antiproliferative Mechanisms of the Flavonoids 2,2′-Dihydroxychalcone and Fisetin in Human Prostate Cancer Cells [primary; 2010] doi:10.1080/01635581003605524
  • Finding: DHC and fisetin caused dose-dependent reduction in viability and increase in apoptosis in PC3 cells at 72 h.
  • Population: PC3 human prostate cancer cells
  • Intervention/exposure: DHC and fisetin (1-50 μM)
• <p>Antiviral and immunomodulatory effects of polyphenols on macrophages infected with dengue virus serotypes 2 and 3 enhanced or not with antibodies</p> [primary; 2019] doi:10.2147/idr.s210890
  • Finding: Only quercetin and fisetin inhibited DENV-2 and DENV-3 infection in the absence or presence of enhancing antibody (>90%, p<0.001);
  • Population: Human U937-DC-SIGN macrophages infected with dengue virus serotypes 2 or 3
  • Intervention/exposure: quercetin and fisetin
  • Comparator: infection without polyphenols
• Dual targeting of mTOR/IL-17A and autophagy by fisetin alleviates psoriasis-like skin inflammation [primary; 2023] doi:10.3389/fimmu.2022.1075804
  • Finding: 12,713 differentially expressed genes (DEGs) in the fisetin-treated group compared to 7,374 DEGs in the rapamycin-treated group
  • Population: HEKa cells (adult human epidermal keratinocytes)
  • Intervention/exposure: fisetin treatment
  • Comparator: rapamycin treatment
• Fisetin, a 3,7,3′,4′-Tetrahydroxyflavone Inhibits the PI3K/Akt/mTOR and MAPK Pathways and Ameliorates Psoriasis Pathology in 2D and 3D Organotypic Human Inflammatory Skin Models [primary; 2019] doi:10.3390/cells8091089
  • Finding: Fisetin treatment significantly inhibited the activation of p38 and JNK, but had enhanced effect on ERK1/2.
  • Population: TNF-α stimulated NHEKs
  • Intervention/exposure: fisetin

Source synthesis

This receipt-backed scoping note has one bounded signal: fisetin shows endpoint-specific favorable signals with context limits across this 5-source primary bundle (2010-2023). Grouped by direction: directionally favorable: 3 receipt(s) | other/mixed: 2 receipt(s). The source facts cover 5 population context(s) and 4 intervention/exposure context(s), so this is a scoping signal about where endpoints diverge, without establishing a causal, clinical, species-translated, or mechanistically integrated claim. The listed effect sizes remain source-specific across endpoints and populations; they are not pooled or averaged. This is a heterogeneous indication/context map, not a unified disease-specific or endpoint-family claim. Concrete source-level examples: IC50 of fisetin 3.4 ± 0.3 μM on senescent cells versus 7.0 ± 0.4 μM on control cells; DHC and fisetin caused dose-dependent reduction in viability and increase in apoptosis in PC3 cells at 72 h; Only quercetin and fisetin inhibited DENV-2 and DENV-3 infection in the absence or presence of enhancing antibody (>90%, p<0.001);.

Directional grouping

• directionally favorable: fisetin is the intervention/exposure and the reported clinical endpoint favors that arm.

• comparator/not favorable: fisetin is the comparator arm; the label is limited to that head-to-head endpoint.

• economic/context only: the receipt reports cost, QALY, or economic context rather than a clinical efficacy endpoint.

• non-clinical/predictive: the receipt reports descriptive modelling, prediction, or age-clock performance rather than an intervention endpoint.

• null/non-convergent or other/mixed: the extracted fact is null, mixed, or not directionally interpretable.

• other/mixed: Intermittent supplementation with fisetin improves arterial function in old mice by decreasing cellular senescence — IC50 of fisetin 3.4 ± 0.3 μM on senescent cells versus 7.0 ± 0.4 μM on control cells

• directionally favorable: Antiproliferative Mechanisms of the Flavonoids 2,2′-Dihydroxychalcone and Fisetin in Human Prostate Cancer Cells — DHC and fisetin caused dose-dependent reduction in viability and increase in apoptosis in PC3 cells at 72 h.

• directionally favorable: <p>Antiviral and immunomodulatory effects of polyphenols on macrophages infected with dengue virus serotypes 2 and 3 enhanced or not with antibodies</p> — Only quercetin and fisetin inhibited DENV-2 and DENV-3 infection in the absence or presence of enhancing antibody (>90%, p<0.001); ( mechanistic ablation supports the topic effect; not a comparator outcome)

• other/mixed: Dual targeting of mTOR/IL-17A and autophagy by fisetin alleviates psoriasis-like skin inflammation — 12,713 differentially expressed genes (DEGs) in the fisetin-treated group compared to 7,374 DEGs in the rapamycin-treated group

• directionally favorable: Fisetin, a 3,7,3′,4′-Tetrahydroxyflavone Inhibits the PI3K/Akt/mTOR and MAPK Pathways and Ameliorates Psoriasis Pathology in 2D and 3D Organotypic Human Inflammatory Skin Models — Fisetin treatment significantly inhibited the activation of p38 and JNK, but had enhanced effect on ERK1/2. ( mechanistic ablation supports the topic effect; not a comparator outcome)

Specific moderators in this bundle are population/indication (HEKa cells (adult human epidermal keratinocytes); Human U937-DC-SIGN macrophages infected with dengue virus serotypes 2 or 3; PC3 human prostate cancer cells; TNF-α stimulated NHEKs; senescent human umbilical vein endothelial cells (HUVECs)), study design/evidence type (primary).

Context separation

The selected receipts group because each carries a fact-level extraction for fisetin; they separate by context (human clinical/observational and other source context) and endpoint, so they are not interchangeable evidence for one pooled claim.

Boundary limits

Source-literature boundary for fisetin: the listed sources define one bounded, context-dependent signal across separate source contexts. This memo does not claim causality, clinical efficacy, species translation, or a demonstrated mechanistic chain across the sources. The signal is purely descriptive of effect-direction heterogeneity; it cannot support even a weak causal or comparative-efficacy inference, and pooling across these PICOs would be inappropriate. Routing domain longevity_research is publication-lane metadata only; the source scope here is defined by the selected fisetin receipts.

Next gaps

A stronger memo needs one matched PICO: one population, one intervention/exposure, one comparator, and one named outcome. If fisetin is promoted beyond a scoping note, the next run should select sources sharing one context family rather than mixing human clinical/observational and other source context.