Rosa chinensis cv. ‘JinBian’ flowers alleviates brain damage and cognitive deficit by inhibiting ferroptosis via the Keap1/Nrf2/GPX4 pathway and regulating gut microbiota

Background The flowers of Rosa chinensis cv. ‘JinBian’ (RCF) has been utilized as a herbal tea for millennia to prevent aging-related diseases. RCF is enriched in flavonoids and exhibits significant antioxidant effects for anti-aging potential. However, the specific bioactive compounds and their underlying anti-aging mechanisms remain unclear. Purpose This study aimed to investigate the bioactive ingredients and neuroprotective mechanisms of RCF extracts. Methods The study obtained dichloromethane (RD), ethyl acetate (RE), n-butanol (RB), and residual water (RW) fractions from RCF after liquid-liquid extraction. It investigated their neuroprotective effect in in vitro and in vivo experiments. UHPLC-ESI-HRMS/MS analysis was used to identify phytochemicals in RE. In vitro assays included measuring phenolic and flavonoid contents, ABTS⁺ and DPPH + scavenging capacities, and effects on H₂O₂-induced SHSY-5Y cells. In vivo , D-galactose-induced mice were used and assessed through the Morris water maze test and the crucifixion anxiety test. Molecular pathways and gut microbiota were analyzed. Results Among the fractions, RE had the highest phenolic and flavonoid contents, the strongest ABTS⁺ and DPPH + scavenging capacities, and significantly inhibited ROS accumulation by increasing antioxidants (glutathione, catalase, superoxide dismutase) in H₂O₂-induced SHSY-5Y cells. UHPLC-ESI-HRMS/MS analysis identified 28 phytochemicals in RE, primarily gallic acid derivatives and flavonoid derivatives. In D-galactose-induced mice, RE alleviated memory impairment and anxiety-like behavior. RE ameliorated brain damage by activating the Keap1/Nrf2-regulated antioxidant pathway (increasing T-AOC, GSH, GPX4, NQO1, SOD1, HO-1), suppressing ferroptosis, inhibiting acetylcholinesterase activity, attenuating GSK-3β/Tau/Bcl-2 axis-regulated apoptosis, and modulating AMPK-regulated autophagy. Additionally, RE improved gut microbiota diversity, particularly increasing beneficial bacteria such as Lactobacillus and Bifidobacterium . Conclusions Therefore, RE could alleviate the cognitive deficit associated with age-related neurodegenerative diseases by targeting ferroptosis-related oxidative stress, apoptosis, and autophagy, as well as modulating the gut microbiota.