Atherosclerosis is caused by injury to the blood arteries and progressive oxidative stress. Blood cells play an important role in its development; thus, their protection is important. Naringenin (N) is documented to possess a protective action against atherosclerosis, and we hypothesize that its derivatives, naringin (Nr) and naringin dihydrochalcone (Nd), with slightly different structures, possess similar or better activity. Therefore, this research aimed to find the mechanism of protective action of N, Nr and Nd in relation to erythrocytes, peripheral blood mononuclear cells (PBMCs) and platelets in terms of their potential anti-atherosclerotic effect. Moreover, their physicochemical properties and the interaction of flavonoids with liposomes were studied. All flavonoids protected erythrocytes from AAPH- and H₂O₂-induced oxidation to varying degrees. None of them had a destructive effect on erythrocyte membrane, and they did not impact the metabolic activity of PBMC and platelets. Nr and Nd inhibited collagen-induced platelet aggregation better in tested concentrations than N. Studied compounds did not induce liposome aggregation, but N and Nd changed their dipole potential. Obtained results show that Nd possesses slightly better activity than N and may have a better potential health effect on blood cells, which is very important in the design of anti-atherosclerotic therapeutics.

Sea buckthorn and Japanese knotweed are known in many traditional medicine systems to be a great source of bioactive substances. This research aims to compare the bioactivity and protective effects of the phenolic extracts of leaves from sea buckthorn and roots and leaves from the Japanese knotweed on erythrocytes. The polyphenol composition of the extract was analyzed using UPLC-PDA-ESI-MS/MS. The extracts’ toxicity and impact on the erythrocytes’ osmotic fragility were measured spectrophotometrically. The antioxidant activity was determined based on the inhibition of oxidation of erythrocytes and their membrane induced by 2,2′-Azobis(2-methylpropionamidine) dihydrochloride (AAPH),measured spectrophotometrically and using fluorimetry. To find the possible mechanism of the extracts’ action, extract-modified cells were observed under a microscope, and the potential localization of the extract’s phytochemical composition was checked using fluorescent probes. The results showed that the used extracts are not toxic to erythrocytes, increase their osmotic resistance, and successfully protect them against free radicals. Extract components localize on the outer part of the membrane, where they can scavenge the free radicals from the environment. Altogether, the presented extracts can greatly protect living organisms against free radicals and can be used to support the treatment of diseases caused by excess free radicals.

In the pursuit of novel anticancer therapies, assessing their selectivity and safety profile towards healthy cells is crucial. This study investigated chlorochalcones, derivatives of 2′-hydroxychalcone containing a chlorine atom, for their impact on human breast cancer cells (MCF-7 and MDA-MB-231), healthy blood cells (erythrocytes, peripheral blood mononuclear cells (PBMCs), platelets), and microvascular endothelial cells (HMEC-1). Our findings demonstrated that chlorochalcones did not detrimentally affect erythrocytes, showing no hemolysis or preserving osmotic resistance and transmembrane potential. They also exhibited minimal impact on normal PBMC viability and varying effects on platelet metabolic activity at therapeutic concentrations. Importantly, these derivatives displayed lower toxicity towards HMEC-1 endothelial cells than towards breast cancer cells, indicating a degree of selectivity. Chlorochalcones have high antiproliferative activity against cancer cells, primarily by inducing apoptosis with virtually no significant impact on cell cycle progression. Their mechanism of action involves the modulation of reactive oxygen species (ROS) levels and induction of mitochondrial dysfunction, including membrane depolarization and reduced mitochondrial mass. Biological activity, including toxicity and ROS modulation, is dependent on the position and number of chlorine atoms. In conclusion, this study highlights the ability of chlorochalcones to effectively target malignant cells while sparing normal circulatory and endothelial cells, thus positioning them as a promising class of candidates for further anticancer drug development.

Chalcones are tunable electrophiles whose bioactivity depends on aryl substitution and membrane interactions. We profiled eight 4'-hydroxychalcones with differing in methoxy topology on ring B in primary human PBMCs (24 h, XTT) and canine lymphoma/leukemia cell lines (CLBL-1, CLB70; 72 h, MTT), integrating RBC compatibility assays (hemolysis, morphology, osmotic fragility C50, transmembrane potential, and reduced glutathione), hemoglobin tryptophan-fluorescence quenching, and cell-free antioxidant assays. In canine tumor models, chalcones were more cytotoxic to neoplastic than to normal cells, indicating selectivity. Among them, 3-methoxy-4'-hydroxychalcone showed the most favorable profile, combining strong anticancer activity in CLBL-1 and CLB70 with lower toxicity toward normal cells, whereas 2,5-dimethoxy-4'-hydroxychalcone, although potent, showed a less favorable safety profile. RBC studies revealed marked echinocytosis after 1 h at 100 µM without acute hemolysis and no changes in osmotic resistance, transmembrane potential, or GSH levels. After 24 h, hemolysis was observed only for two compounds at concentrations ≥ 200 µM. Hb quenching was static (Kq above the diffusion limit), with the highest Ksv values for 3-methoxy-4'-hydroxychalcone and 4'-hydroxychalcone, but the highest Kb for 3,4,5-trimethoxy-4'-hydroxychalcone, followed by 4'-hydroxychalcone, indicating that fluorophore proximity and complex stability are not directly coupled. DPPH and CUPRAC assays showed no detectable direct antioxidant activity, whereas ABTS•+ revealed weak and comparable radical-scavenging activity across the series. A concise SAR emerged: meta- and ortho/meta-methoxy substitution enhanced biological activity, whereas para-methoxy and 3,4,5-trimethoxy substitution attenuated it; the unsubstituted parent compound retained substantial activity. Overall, methoxy topology shapes both cytotoxicity and interactions with blood components, with 3-methoxy-4'-hydroxychalcone emerging as the most promising lead for early preclinical evaluation.

Diosmin, a flavonoid with documented vascular-protective properties, together with the closely related compounds diosmetin and diosmetin-7-O-glucoside, has not previously been subjected to a systematic comparative biophysical characterization. In this study, we performed an integrated biophysical comparison of these three structurally related flavonoids to delineate how structural differences translate into distinct patterns of metal-ion coordination, membrane interaction and hemoglobin engagement, thereby providing a mechanistic context for their behavior in complex erythrocyte- and simplified hemoglobin-based redox systems. All three compounds exhibited low direct radical-scavenging activity in the DPPH• assay and showed differences in predicted lipophilicity and metal-ion interactions. Diosmetin, the most lipophilic derivative, selectively chelated Cu ²⁺ /Cu ⁺ , while diosmin showed the strongest chelation of both Fe ²⁺ and Fe ³⁺ ; none of the tested flavonoids reduced iron ions. Diosmetin inhibited rat intestinal α-glucosidase, and both diosmetin and diosmin inhibited lipoxygenase with comparable potency. In intact human erythrocytes, all flavonoids did not cause hemolysis and did not alter osmotic resistance within the concentration range tested, but they differentially affected cell morphology and response to Fe ³⁺ -induced oxidative stress. Diosmin and diosmetin-7-O-glucoside predominantly induced echinocyte formation, whereas diosmetin favored stomatocytes and, at the highest concentration, partially reduced Fe ³⁺ -induced hemolysis. Measurements in erythrocyte-mimetic liposomes showed no effect of any compound on acyl chain order, while diosmetin induced a pronounced decrease in membrane dipole potential, in contrast to the modest changes observed for diosmin, indicating different modes of interaction with the lipid headgroup region. All three flavonoids quenched the hemoglobin tryptophan fluorescence via a static mechanism, with a similar quenching efficiency but differing binding constants. ATR-FTIR spectroscopy did not reveal detectable alterations in the overall secondary-structure content of hemoglobin. Collectively, the results demonstrate systematic differences among diosmetin, diosmetin-7-O-glucoside and diosmin in metal-ion coordination, membrane-related effects and hemoglobin interactions, providing a comparative biophysical basis for distinguishing their activities. Based on these results, diosmetin appears to be a particularly interesting candidate for further biophysical and functional investigation.