The efficient separation of bioactive components from Eucommia ulmoides Oliver using membrane filtration technology and its mechanisms in preventing alcoholic liver disease

The efficient extraction and purification of active components from Eucommia ulmoides Oliver (EUO) are crucial for their utilization. The structure and properties of the prepared EUO leaf polysaccharides (ELPs) and extractum (ELE) were comprehensively characterized in this study, and the intervention mechanism of the EUO polysaccharides and extractum in alcoholic liver disease (ALD) were investigated. The yield of EUO extractum was 24.82 %, from which nine active components were identified. The yield of EUO leaf polysaccharides was 8.06 %, and the polysaccharides were fractionated into three components ELP1, ELP2, and ELP3 through ultrafiltration technology, with yields of 4.19 %, 1.26 %, and 2.59 %, respectively. Ultrafiltration significantly reduced protein content, enhanced polysaccharide homogeneity, and altered monosaccharide composition. ELP3 exhibited higher scavenging efficacy on •OH and ABTS•⁺ than ELP1 and ELP2, reaching 82.53 % and 88.41 % respectively. ELP3 and ELE intervention preserved liver integrity, mitigated lipid accumulation and inflammation, and regulated hepatic oxidative stress. Moreover, they maintained intestinal barrier function, suppressed harmful bacteria (Escherichia-Shigella, and UBA1819), and promoted beneficial bacteria (Dubosiella, Monoglobus, and Lachnospiraceae). Thirteen hallmark differential metabolites were identified, and KEGG pathway enrichment analysis suggested that ELP3 and ELE may ameliorate ALD through pathways like longevity regulation, choline metabolism in cancer, oxidative phosphorylation, and AMPK signaling pathway. This investigation holds significance in delineating the beneficial effects of ELP3 and ELE in ALD alleviation.