Health Promotion Potential of Vegetables Cultivated in Northern Thailand: A Preliminary Screening of Tannin and Flavonoid Contents, 5α-Reductase Inhibition, Astringent Activity, and Antioxidant Activities

In the 2017 study, 17 vegetables from Northern Thailand were investigated for their health benefits, including their content of tannins and flavonoids, ability to inhibit 5α-reductase, astringency, and antioxidant properties. The study revealed that Spondias pinnata had the highest tannin content, Ocimum americanum had the highest flavonoid content, and Neptunia oleracea was the most effective at inhibiting 5α-reductase, which is significant for treating conditions like androgenic alopecia. Additionally, Spondias pinnata showed the strongest antioxidant activity in ABTS radical scavenging and ferric reducing assays, Polygonatum odoratum was the best at scavenging hydrogen peroxide, and Leucaena leucocephala excelled in DPPH radical scavenging. These results indicate that these vegetables have potential as ingredients in nutritional supplements, preventive medicines, and cosmetic products.