Isolation of Tricin as a Xanthine Oxidase Inhibitor from Sweet White Clover (Melilotus albus) and Its Distribution in Selected Gramineae Species

Abstract

Xanthine oxidase, an enzyme present in significant levels in the intestine and liver, metabolizes hypoxanthine to xanthine and xanthine to uric acid in the purine catabolic pathway. An inhibitory compound acting against xanthine oxidase was isolated from sweet white clover (Melilotus albus) by bioassay and high-performance liquid chromatography guided separation. It was identified as tricin by spectroscopic analysis. Tricin possessed a potent xanthine oxidase inhibitory activity with an IC50 value of 4.13 μM. Further inhibition kinetics data indicated it to be a mixed-type inhibitor and Ki and KI values were determined to be 0.47 μM and 4.41 μM. To find a rich source of tricin, the distribution of tricin in seven different tissues from four Gramineae species was investigated by high-performance liquid chromatography analysis. The highest amount (1925.05 mg/kg dry materials) was found in the straw of wheat, which is considered as a potentially valuable source of natural tricin.

Identification of Transient Receptor Potential Vanilloid 3 Antagonists from Achillea alpina L. and Separation by Liquid-Liquid-Refining Extraction and High-Speed Counter-Current Chromatography

“…Bioassay-guided fractionation of the ethanol extract of the dried whole herbs of A. alpina was performed to search for the bioactive constituents responsible for the inhibitory activity on TRPV3 channel. Liquid-liquid extraction is the simplest and most effective method for the separation of complex mixtures, which is widely used in the first step of extract separation [18,19]. So, the extract was initially partitioned by sequential solvent extraction with n-hexane, ethyl acetate, and n-butanol.…”

Determination of flavonoid content in Grammatophyllum speciosum and in vitro evaluation of their anti-skin cancer and antibacterial activities

“…For the flavones, orientin, tricin, and vitexin have been reported for antioxidant activity [ 39 , 40 ], whereas tricin, vitexin, isovitexin, and isorhametin were previously reported for their anti-cancer activities. Isovitexin was demonstrated to inhibit the growth of a breast cancer cell line [ 41 ], while tricin inhibited the mortality of colon cancer cells and could suppress the growth and metastasis of lung cancer in a mouse model [ 42 ].…”

Gut microbiota plays a significant role in gout

“…Intestinal barrier dysfunction leads to increased serum LPS levels, and chronic inflammation is often accompanied by the increase of XOD activity. XOD, an enzyme present in significant levels in the intestine and liver, metabolizes hypoxanthine to xanthine and xanthine to uric acid in the purine catabolic pathway [34]. XOD is the key enzyme in uric acid production, and the increase of XOD activity can lead to the increase of uric acid production.…”