Screening of medicinal plant extracts in Vietnam and investigation of their combination for preventing and treating gout

Objectives. The study aimed to examine the potential use of ethanol extracts of four medicinal plants to prevent and treat gout disease.Methods. An investigation of some typical compound contents such as polyphenols, flavonoids, and tannins in terms of two bioactive abilities, including anti-xanthine oxidase and antioxidant was carried out in Eclipta prostrata L., Artemisia vulgaris L., Apium graveolens L., and Piper betle L samples. Subsequently, the weight ratios of Piper betle L. and Artemisia vulgaris L. were investigated to reduce the total tannin content and get the most suitable anti-xanthine oxidase activity.Results. As well as having the highest target compound contents, Piper betle L. demonstrated the best anti-xanthine oxidase and antioxidant abilities even while its IC50 values were lower than positive control; however, its high total tannin content can cause some side effects. A mixture with a weight ratio of 1:1 of Piper betle L. and Artemisia vulgaris L. had a total tannin content half that of Piper betle L. as well as demonstrating potential anti-xanthine oxidase and antioxidant activities when IC50 was about 3.94 and 20.85 µg/mL, respectively.Conclusions. Out of the four selected plants, Piper betle L. demonstrated the best potential material for preventing and treating gout disease. However, due to the high tannin content in it, a mix of Piper betle L. and Artemisia vulgaris L. at a weight ratio of 1:1 gave optimal results for application in treatment.