Astragalus membranaceus polysaccharide (APs) and Eugenol: Multi-target Anti-inflammatory, Antioxidant, Antimicrobial,...

Astragalus membranaceus is a traditional medicinal plant with diverse therapeutic properties largely attributed to its polysaccharides (APs). This study evaluated the antimicrobial, anti-inflammatory, antioxidant, and anticancer activities of APs and eugenol, both individually and in combination, against multidrug-resistant (MDR) pathogens and HepG2 liver cancer cells. Thirty bacterial and ten Candida isolates were recovered from skin abscesses, with five identified as MDR strains (Staphylococcus haemolyticus, S. aureus, E. coli, Acinetobacter baumannii, and Candida auris), confirmed by 16S rDNA and ITS sequencing. Both APs and eugenol exhibited marked antimicrobial activity, while their combination achieved the strongest inhibition (up to 27.3 ± 0.4 mm). C. auris was highly sensitive to APs alone (MIC: 2 ± 0.2 µg/mL). The combination also significantly downregulated IL-6, IL-17, and TNF-α levels, and showed potent COX-2 inhibition (0.10 ± 0.01 µg/mL), surpassing celecoxib (0.9 ± 0.05 µg/mL). Antioxidant analysis (DPPH assay) revealed superior radical scavenging by the combination (57.5 ± 1.3 % %). Molecular docking confirmed the activity of eugenol, showing favorable binding to DNA gyrase B, sterol demethylase, COX-2, xanthine oxidase, and caspase-3, with the strongest affinity for xanthine oxidase (-5.25 kcal/mol). In anticancer assays, eugenol induced dose-dependent inhibition of HepG2 cell proliferation, while APs displayed limited cytotoxicity. Notably, the combination reduced cell viability to 3.77 ± 0.4 % % at 400 µg/mL, consistent with apoptotic changes. Collectively, these findings highlight the synergistic potential of APs and eugenol as a multi-target therapeutic approach against MDR infections, inflammation, oxidative stress, and liver cancer.