Numerous beneficial effects of resveratrol were reported; however, its pharmacological profile is contradictious. Previously, we have demonstrated that resveratrol has a dose-dependent cytoprotective effect and the essential role of autophagy induction was demonstrated. Resveratrol suffers from unfavorable pharmacokinetics, hindering its clinical use. Our aim was to study the cytoprotective effect of resveratrol derivatives to better understand structure–activity relationships that may facilitate the development of compounds with better druglike characteristics. Serum-deprivation-induced caspase activation, free radical generation, mitochondrial membrane depolarization and autophagy were detected in the presence of resveratrol analogs with different oxidation states on mouse embryonal fibroblasts. Distinct cytoprotective mechanisms of the examined compounds were revealed. Monomethyl resveratrol had similar potency to resveratrol (EC₅₀: 85.3 vs. 84.2 μM); however, autophagy induction was not essential for its cytoprotective effect. Oxyresveratrol was found to be a strong antioxidant that can induce direct cytoprotection rather than autophagy. Trimethyl-resveratrol, lacking free hydroxyl groups, induced damage that was too significant and hardly compensated by the activation of cytoprotective machineries, and caspase activation was reduced by only 24.5%. Based on our results, methylation of resveratrol reduces its antioxidant activity, while autophagy induction can still contribute to its cytoprotective effect. The introduction of an additional hydroxyl group, however, augments the antioxidant properties, inducing cytoprotection without autophagy induction.

Neuroinflammation is a key process in Alzheimer’s disease (AD). We aimed to examine the development and evaluation of a comprehensive in vitro model that captures the complex interplay between neurons and immune cell types. Retinoic acid-differentiated SH-SY5Y neuroblastoma cells exposed to LPS-conditioned media (CM) from RAW264.7 macrophages, BV2 microglia, and HL60 promyelocytic cells differentiated into neutrophil- or monocyte-like phenotypes were analyzed. The effects of CM containing inflammatory factors on neuronal viability and function were systematically evaluated. Neuronal oxidative stress, mitochondrial function, autophagy and protein aggregates were analyzed. The involvement of insulin resistance was studied by assaying glucose uptake and determining its IC₅₀ values for cell viability improvement and GSK3β phosphorylation. After short-term exposure (3 h), most inflammatory CMs induced peroxide production in neurons, with the strongest effect observed in media from DMSO- or RA-differentiated HL60 cells. Mitochondrial membrane potential was markedly reduced by LPS-stimulated BV2 and HL60-derived CMs. Prolonged exposure (72 h) revealed partial normalization of oxidative stress and mitochondrial membrane potential. Glucose uptake was significantly impaired in cells treated with LPS-activated RAW264.7, BV2, and DMSO-differentiated HL60 cell media, while insulin partially rescued this effect, except for the CM of BV2 cells. Notably, insulin IC₅₀ increased dramatically under LPS-treated BV2 cells induced inflammation (35 vs. 198 pM), confirming the development of insulin resistance. Immune cell-specific inflammation causes distinct effects on neuronal oxidative stress, mitochondrial function, protein aggregation, insulin signaling and viability. LPS-activated BV2-derived CM best recapitulates AD-related pathology, offering a relevant in vitro model for further studies.

Background and Objectives: Expansion of white adipose tissue causes systemic inflammation and increased risk of metabolic diseases due to its endocrine function. Resveratrol was suggested to be able to prevent obesity-related disorders by mimicking caloric restriction; however, its structure–activity relationships and molecular targets are still unknown. We aimed to compare the effects of resveratrol and its analogues on adipocyte metabolism and lipid accumulation in vitro. Methods: Mouse embryonic fibroblasts were differentiated to adipocytes in the absence or presence of resveratrol or its derivatives (oxyresveratrol, monomethylated resveratrol, or trimethylated resveratrol). Intracellular lipid content was assessed by Oil Red O staining. Glucose uptake and its response to insulin were estimated by 2-NBDG, and mitochondrial activity was assayed via resazurin reduction. Involvement of potential molecular pathways was investigated by concurrent treatment with their inhibitors. Results: Although lipid accumulation was significantly reduced by all analogues without altering protein content, oxyresveratrol was the most potent (IC50 = 4.2 μM), while the lowest potency was observed with trimethylated resveratrol (IC50 = 27.4 μM). Increased insulin-stimulated glucose uptake was restored by each analogue with comparable efficiency. The enhanced mitochondrial activity was normalized by resveratrol and its methylated derivatives, while oxyresveratrol had a minor impact on it. Among the examined pathways, inhibition of SIRT1, PGC-1α, and JNK diminished the lipid-reducing effect of the compounds. Autophagy appeared to play a key role in the effect of all compounds but oxyresveratrol. Conclusions: Resveratrol and its analogues can mimic caloric restriction with complex mechanisms, including activation of SIRT1, PGC-1α, and JNK, making them possible drug candidates to treat obesity-related diseases.

Alzheimer’s disease (AD) is characterized by mitochondrial dysfunction, oxidative stress, insulin resistance, and aberrant protein aggregation. Neurodegeneration model with neuronal insulin resistance was induced in SH-SY5Y human neuroblastoma cells by streptozotocin (STZ). We evaluated the neuroprotective effects of resveratrol (RZV) and three structural analogs: oxyresveratrol (OXI), monomethyl resveratrol (MONO), and trimethyl resveratrol (TRI). Mitochondrial function, plasma membrane integrity, oxidative stress) and autophagy were studied by fluorescent assays. Phosphorylated GSK3 levels were measured by ELISA as an indicator of insulin sensitivity. TRI exhibited significant mitochondrial protective effects and strongly induced autophagy. OXI demonstrated excellent antioxidant activity but showed no detectable mitochondrial protective or autophagy-inducing effects. RZV and MONO exhibited moderate antioxidant effects along with strong insulin-sensitizing and autophagy-inducing properties. Insulin sensitivity was most potently restored by RZV (IC₅₀ = 54 pM) and MONO (IC₅₀ = 50 pM), whereas TRI (IC₅₀ = 160 pM) was less potent, and OXI (IC₅₀ = 97 pM) showed moderate potency. Our findings suggest that the neuroprotective effects of resveratrol analogs significantly depend on their molecular structure and that they exert their beneficial effects through distinct mechanisms. This research may contribute to the development of novel, multi-target compounds for the treatment of neurodegenerative diseases.