Background: Cellular senescence is a biological process with a dual role in organismal health. While transient senescence supports tissue repair and acts as a tumor-suppressive mechanism, the chronic accumulation of senescent cells contributes to aging and the progression of age-related diseases. Senotherapeutics, including senolytics, which selectively eliminate senescent cells, and senomorphics, which modulate the senescence-associated secretory phenotype (SASP), have emerged as promising strategies for managing age-related pathologies. Among these, polyphenols, a diverse group of plant-derived bioactive compounds, have gained attention for their potential to modulate cellular senescence. Methods: This review synthesizes evidence from in vitro, in vivo, and clinical studies on the senolytic and senomorphic activities of bioactive polyphenols, including resveratrol, kaempferol, apigenin, and fisetin. The analysis focuses on their molecular mechanisms of action and their impact on fundamental aging-related pathways. Results: Polyphenols exhibit therapeutic versatility by activating SIRT1, inhibiting NF-κB, and modulating autophagy. These compounds demonstrate a dual role, promoting the survival of healthy cells while inducing apoptosis in senescent cells. Preclinical evidence indicates their capacity to reduce SASP-associated inflammation, restore tissue homeostasis, and attenuate cellular senescence in various models of aging. Conclusions: Polyphenols represent a promising class of senotherapeutics for mitigating age-related diseases and promoting healthy lifespan extension. Further research should focus on clinical validation and the long-term effects of these compounds, paving the way for their development as therapeutic agents in geriatric medicine.

Plant secondary metabolites, known as phytochemicals, have recently gained much attention in light of the “circular economy”, to reutilize waste products deriving from agriculture and food industry. Phytochemicals are known for their onco-preventive and chemoprotective effects, among several other beneficial properties. Apple phytochemicals have been extensively studied for their effectiveness in a wide range of diseases, cancer included. This review aims to provide a thorough overview of the main studies reported in the literature concerning apple phytochemicals, mostly polyphenols, in cancer prevention. Although there are many different mechanisms targeted by phytochemicals, the Nrf2 and NF-κB signaling pathways are the ones this review will be focused on, highlighting also the existing crosstalk between these two systems.

The endocannabinoid system (ECS) exerts immunosuppressive effects, which are mostly mediated by cannabinoid receptor 2 (CBR2), whose expression on leukocytes is higher than CBR1, mainly localized in the brain. Targeted CBR2 activation could limit inflammation, avoiding CBR1-related psychoactive effects. Herein, we evaluated in vitro the biological activity of a novel, selective and high-affinity CBR2 agonist, called JT11, studying its potential CBR2-mediated anti-inflammatory effect. Trypan Blue and MTT assays were used to test the cytotoxic and anti-proliferative effect of JT11 in Jurkat cells. Its pro-apoptotic activity was investigated analyzing both cell cycle and poly PARP cleavage. Finally, we evaluated its impact on LPS-induced ERK1/2 and NF-kB-p65 activation, TNF-α, IL-1β, IL-6 and IL-8 release in peripheral blood mononuclear cells (PBMCs) from healthy donors. Selective CB2R antagonist SR144528 and CBR2 knockdown were used to further verify the selectivity of JT11. We confirmed selective CBR2 activation by JT11. JT11 regulated cell viability and proliferation through a CBR2-dependent mechanism in Jurkat cells, exhibiting a mild pro-apoptotic activity. Finally, it reduced LPS-induced ERK1/2 and NF-kB-p65 phosphorylation and pro-inflammatory cytokines release in human PBMCs, proving to possess in vitro anti-inflammatory properties. JT11 as CBR2 ligands could enhance ECS immunoregulatory activity and our results support the view that therapeutic strategies targeting CBR2 signaling could be promising for the treatment of chronic inflammatory diseases.

The qualitative profile of thinned apple polyphenols (TAP) fraction (≈24% of polyphenols) obtained by purification through absorbent resin was fully investigated by LC-HRMS in positive and negative ion mode and using ESI source. A total of 68 polyphenols were identified belonging to six different classes: flavanols, flavonols, dihydrochalchones, flavanones, flavones and organic and phenolic acids. The antioxidant and anti-inflammatory activities were then investigated in cell models with gene reporter for NRF2 and NF-κB and by quantitative proteomic (label-free and SILAC) approaches. TAP dose-dependently activated NRF2 and in the same concentration range (10–250 µg/mL) inhibited NF-κB nuclear translocation induced by TNF-α and IL-1α as pro-inflammatory promoters. Proteomic studies elucidated the molecular pathways evoked by TAP treatment: activation of the NRF2 signaling pathway, which in turn up-regulates protective oxidoreductases and their nucleophilic substrates such as GSH and NADPH, the latter resulting from the up-regulation of the pentose phosphate pathway. The increase in the enzymatic antioxidant cellular activity together with the up-regulation of the heme-oxygenase would explain the anti-inflammatory effect of TAP. The results suggest that thinned apples can be considered as a valuable source of apple polyphenols to be used in health care products to prevent/treat oxidative and inflammatory chronic conditions.

The present paper reports a sustainable raw material obtained from the by-products derived from the industrial production of bergamot (Citrus × Bergamia Risso & Poiteau) essential oils. The procedure to obtain the raw material is designed to maintain as much of the bioactive components as possible and to avoid expensive chemical purification. It consists of spray-drying the fruit juice obtained by squeezing the fruits, which is mixed with the aqueous extract of the pulp, i.e., the solid residue remained after fruit pressing. The resulting powder bergamot juice (PBJ) contains multiple bioactive components, in particular, among others, soluble fibers, polyphenols and amino-acid betaines, such as stachydrine and betonicine. LC-MS analysis identified 86 compounds, with hesperetin, naringenin, apigenin and eridictyol glucosides being the main components. In the second part of the paper, dose-dependent anti-inflammatory activity of PBJ and of stachydrine was found, but neither of the compounds were effective in activating Nrf2. PBJ was then found to be effective in an in vivo model of a metabolic syndrome induced by a high-sugar, high-fat (HSF) diet and evidenced by a significant increase of the values related to a set of parameters: blood glucose, triglycerides, insulin resistance, systolic blood pressure, visceral adipose tissue and adiposity index. PBJ, when given to control rats, did not significantly change these values; in contrast, they were found to be greatly affected in rats receiving an HSF diet. The in vivo effect of PBJ can be ascribed not only to bergamot polyphenols with well-known anti-inflammatory, antioxidant and lipid-regulating effects, but also to the dietary fibers and to the non-phenolic constituents, such as stachydrine. Moreover, since PBJ was found to affect energy homeostasis and to regulate food intake, a mechanism on the regulation of energy homeostasis through leptin networking should also be considered and deserves further investigation.