Flavonoid Glycosides Isolated from Unique Legume Plant Extracts as Novel Inhibitors of Xanthine Oxidase

Abstract

Legumes and the polyphenolic compounds present in them have gained a lot of interest due to their beneficial health implications. Dietary polyphenolic compounds, especially flavonoids, exert antioxidant properties and are potent inhibitors of xanthine oxidase (XO) activity. XO is the main contributor of free radicals during exercise but it is also involved in pathogenesis of several diseases such as vascular disorders, cancer and gout. In order to discover new natural, dietary XO inhibitors, some polyphenolic fractions and pure compounds isolated from two legume plant extracts were tested for their effects on XO activity. The fractions isolated from both Vicia faba and Lotus edulis plant extracts were potent inhibitors of XO with IC50 values range from 40–135 µg/mL and 55–260 µg/mL, respectively. All the pure polyphenolic compounds inhibited XO and their Ki values ranged from 13–767 µM. Ten of the compounds followed the non competitive inhibitory model whereas one of them was a competitive inhibitor. These findings indicate that flavonoid isolates from legume plant extracts are novel, natural XO inhibitors. Their mode of action is under investigation in order to examine their potential in drug design for diseases related to overwhelming XO action.

Tryptophan-containing milk protein-derived dipeptides inhibit xanthine oxidase

“…Amino acids have been reported to display a lower anti-oxidant activity compared to peptides as they have a lower radical scavenging activity [19]. In contrast, we found that Trp displayed a similar XO IC 50 inhibition has yet to be fully determined [79] No XO inhibition was observed with hydrolyzates of complex protein substrates such as WPI, WPI Ret and NaCN. This may be due to the fact that eventhough the bioactive sequences are present within these protein substrates, their abundance may be too low to observe any bioactivity.…”

“…These include consumption of fruits, vegetables and low-fat dairy products and a decrease in meat, seafood and beer intake [44]. Different natural compounds, mainly plant extracts have been used for their XO inhibitory properties [50,65,79,85,90,92].…”

In vitro Study of Xanthine Oxidase Inhibitory of Gambir (Uncaria gambir) Hunter Roxb Extracts

“…Natural product that contained high flavonoid polyphenols demonstrated antioxidant effects and effectively reduced uric acid as well. 1,2 The effects of antioxidant flavonoid were supposed through scavenging free radical compounds and inhibition of enzymes that produce radical species such as lipoxygenase, cyclooxygenase and xanthine oxidase. noids (+) catechin that is about 40-80% of dry water extract weight.…”

Re-evaluating TiCl4 and UV assays for detection of vicine and convicine in high-throughput screening of immature and mature seeds of faba bean

“…Green pods of faba bean are a significant source of L-DOPA (Burbano et al, 1995) which is used for treating Parkinson disease (Seeberger and Hauser, 2009) and for overcoming low libido in human (Hulse, 1994). Faba beans contain significant amounts of flavanoid glycosides which inhibit xanthine oxidase (XO) (Spanou et al, 2012), XO inhibitors are beneficial in vascular disorders (George and Struthers, 2008).…”

“…Green pods of faba bean are a significant source of L-DOPA (Burbano et al, 1995) which is used for treating Parkinson disease (Seeberger and Hauser, 2009) and for overcoming low libido in human (Hulse, 1994). Faba beans contain significant amounts of flavanoid glycosides which inhibit xanthine oxidase (XO) (Spanou et al, 2012), XO inhibitors are beneficial in vascular disorders (George and Struthers, 2008).Presence of some anti-nutritional factors limits faba bean use in the food and feed industry. In humans, aglycones of vicine (2,6-diamino-4,5-dihydroxypyrimidine-5-[β-D-glucopyranoside]) and convicine (2,4,5-trihydroxy-6-aminopyrimidine-5-[β-D-glucopyranoside]), divicine and isouramil, respectively, are responsible for the favism in individuals who carry specific alleles that cause deficient, non-functional or low functional G6P dehydrogenase (G6PD) enzymes (Mason et al, 2007).…”