Comparison of Xanthine Oxidase Inhibitory Activities and Phenolic, Fatty Acid, Element, and Vitamin Levels of Four Mushroom Species

Abstract

The purpose of this study was to determine the antioxidant properties and the composition of phenolic compounds, trace elements, vitamins, and fatty acids in the edible mushrooms Helvella leucopus, Tricholoma terreum, Lepista nuda, and Marasmius oreades, as well as their inhibitory effect on xanthine oxidase. Elemental analyses were conducted using ICP-OES. Phenolic compounds and vitamins were performed by HPLC, while identification of fatty acids was performed by GC–MS. HPLC analysis revealed the phenolic compounds in H. leucopus, T. terreum, L. nuda, and M. oreades, with gallic acid being the main compound identified, with levels of 133.04, 246.49, 408.64, and 129.302 μg/g dry weight, respectively. For vitamins, α-tocopherol is the most primary vitamin found with values of 0.6009, 0.79, and 0.3581 μmol/kg dw. GC–MS analysis determined that the fatty acids with linoleic acid are the major fatty acids identified, with percentages of 30.82%, 19.92%, 30.38%, and 20.86%. ICP-OES measurement indicated that trace elements with iron as the dominant trace element were observed, with concentrations of 0.248, 0.237, 0.449, and 0.1998 mmol/kg dw. The XO inhibitory activities of four mushrooms were assayed, with the IC₅₀ values of 39.97, 20.71, 11.71, and 23.85 μg/mL, respectively. L. nuda and T. terreum may be effective for hyperuricemia and gout, which is associated with the results of phenolic compounds, some vitamins, trace elements, and linoleic acid contents on the inhibitory activities against xanthine oxidase. The results of medicinal mushrooms have shown that they could potentially be useful as inhibitors for the prevention of XO-related diseases induced by ROS.