Phytochemical Analysis, and Antioxidant and Hepatoprotective Activities of Chamaerops humilis L. Leaves; A Focus on Xanthine Oxidase

Chamaerops humilis L. is clumping palm of the family Arecaceae with promising health-promoting effects. Parts of this species are utilized as food and employed in folk medicine to treat several disorders. This study investigated the phytochemical constituents of C. humilis leaves and their antioxidant and xanthine oxidase (XO) inhibitory activities in vitro and in vivo in acetaminophen (APAP)-induced hepatotoxicity in rats. The chemical structure of the isolated phytochemicals was determined using data obtained from UV, MS, IR, and 1H-, 13C-NMR spectroscopic tools as well as comparison with authentic markers. Eleven compounds, including tricin 7-O-β-rutinoside, vicenin, tricin, astragalin, borassoside D, pregnane-3,5,6,16-tetrol, oleanolic acid, β-sitosterol and campesterol were isolated from C. humilis ethanolic extract (CHEE). CHEE and the butanol, n-hexane, and dichloromethane fractions exhibited in vitro radical scavenging and XO inhibitory efficacies. The computational findings revealed the tendency of the isolated compounds towards the active site of XO. In vivo, CHEE ameliorated liver function markers and prevented tissue injury induced by APAP in rats. CHEE suppressed hepatic XO, decreased serum uric acid and liver malondialdehyde (MDA), and enhanced reduced glutathione (GSH), superoxide dismutase (SOD), and catalase in APAP-treated rats. CHEE ameliorated serum tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1β in APAP-treated rats. Thus, C. humilis is rich in beneficial phytochemicals that possess binding affinity towards XO. C. humilis exhibited potent in vitro antioxidant and XO inhibitory activities, and prevented APAP hepatotoxicity by attenuating tissue injury, oxidative stress and inflammation.