Doxorubicin is one of the most effective chemotherapeutic agents; however, it has various side effects, such as cardiotoxicity. Therefore, novel methods are needed to reduce its adverse effects. Quercetin is a natural flavonoid with many biological activities. Liposomes are lipid-based carriers widely used in medicine for drug delivery. In this study, liposomal doxorubicin with favorable characteristics was designed and synthesized by the thin-film method, and its physicochemical properties were investigated by different laboratory techniques. Then, the impact of the carrier, empty liposomes, free doxorubicin, liposomal doxorubicin, and quercetin were analyzed in animal models. To evaluate the interventions, measurements of cardiac enzymes, oxidative stress and antioxidant markers, and protein expression were performed, as well as histopathological studies. Additionally, cytotoxicity assay and cellular uptake were carried out on H9c2 cells. The mean size of the designed liposomes was 98.8 nm, and the encapsulation efficiency (EE%) was about 85%. The designed liposomes were anionic and pH-sensitive and had a controlled release pattern with excellent stability. Co-administration of liposomal doxorubicin with free quercetin to rats led to decreased weight loss, creatine kinase (CK-MB), lactate dehydrogenase (LDH), and malondialdehyde (MDA), while it increased the activity of glutathione peroxidase, catalase, and superoxide dismutase enzymes in their left ventricles. Additionally, it changed the expression of NOX1, Rac1, Rac1-GTP, SIRT3, and Bcl-2 proteins, and caused tissue injury and cell cytotoxicity. Our data showed that interventions can increase antioxidant capacity, reduce oxidative stress and apoptosis in heart tissue, and lead to fewer complications. Overall, the use of liposomal doxorubicin alone or the co-administration of free doxorubicin with free quercetin showed promising results.

Background: Chronic cerebral hypoperfusion (CCH), a pathophysiological state linked to vascular dementia and cognitive impairment, involves the NgR1/Lingo-1/p75 signaling complex implicated in neurodegenerative processes. Resveratrol (RES), a neuroprotective compound, was investigated for its potential to mitigate CCH-induced cognitive deficits by targeting this pathway. Objectives: This study examined RES's ability to improve cognitive impairment in CCH by suppressing the NgR1/Lingo-1/p75 complex and downstream RhoA-ROCK2 signaling. Methods: Rats were divided into five groups: Control, CCH + Ethanol (ETH), CCH, CCH + resveratrol (RES), and RES. Chronic cerebral hypoperfusion was induced via permanent bilateral carotid artery occlusion (2VO). Cognitive function was assessed using the Morris Water Maze (MWM). Hippocampal morphology in CA1, CA3, and dentate gyrus (DG) regions was analyzed via H&E staining. The expression levels of Lingo-1, NgR1, P75, RhoA, and ROCK2 signaling pathway were detected by western blot and quantitative real-time PCR (qRT-PCR). Results: Chronic cerebral hypoperfusion rats showed elevated protein expression of Lingo-1, p75, RhoA, and ROCK2, though NgR1 remained unchanged. The RES treatment significantly reduced these protein levels. Similarly, mRNA levels of all five targets increased in CCH, but RES notably lowered Lingo-1 and NgR1 expression. The MWM tests revealed RES improved spatial learning and memory deficits in 2VO rats. H&E staining demonstrated RES’s neuroprotective effects, preserving hippocampal neuron integrity. Conclusions: Resveratrol alleviates CCH-induced cognitive impairment by downregulating the Lingo-1/NgR1/p75 signaling axis and inhibiting RhoA-ROCK2 pathways. These findings highlight RES’s potential as a therapeutic agent for vascular cognitive impairment associated with chronic hypoperfusion.