Inhibitory potential of sea buckthorn leaves extracts and its component casuarictin on pancreatic enzymes and LPS induced TNF-alpha synthesis in human whole blood

This study focused on fractionation of <i>Hippophae rhamnoides</i> L. leaves to obtain higher added value fractions enriched with bioactive compound casuarinin and its isomer casuarictin and to isolate casuarictin and their biological properties. Fractionation with ethylacetate produced fractions enriched with predominantly casuarinin and both isomers casuarinin and casuarictin. The individual compound casuarictin (94% purity) was prepared through liquid-liquid extraction and HPLC. The structure was confirmed by ¹H NMR data. <i>In vitro</i> tests demonstrated that the samples inhibit digestive enzymes amylase and lipase and reduce inflammation in human blood model stimulated by lipopolysaccharide. Casuarictin and the fractions showed a novel inhibitory effect on pancreatic lipase. Additionally, they strongly inhibited the synthesis of tissue necrosis factor alpha (TNFalpha) induced by LPS in human blood <i>ex vivo</i>. These findings suggest potential of seabuckthorn leaves as a new valuable raw material and its active component casuarictin for applications in the nutraceuticals, human diets and so on.