Vegetable soybean (Glycine max (L.) Merr.) leaf extracts: Functional components and antioxidant and anti‐inflammatory activities

Abstract

To investigate ways to extract greater dietary value from the leaves of the vegetable soybean (Glycine max (L.) Merr.) cultivar ‘Kaohsiung No. 9’. Our results indicate that phenolic content and flavonoid content are highest in extracts prepared with 70% methanol and 70% ethanol. The 70% ethanol extracts also had the highest quercetin (135 ± 1.62 µg/g) and kaempferol (450 ± 1.35 µg/g) contents. These results show that flavonoids are a dominant class of compounds in these vegetable soybean leaf extracts and serve as their main source of antioxidants. At an extract concentration of 5 mg/ml, the 70% methanol extracts achieved good antioxidant effects, with a DPPH radical scavenging rate of 80%, and a reducing power of 88%. In assays of anti‐inflammatory capacity using lipopolysaccharide‐stimulated RAW 264.7 macrophages. The 70% methanol extracts displayed the most significant inhibition of nitric oxide (NO) synthesis, achieving up to 86% inhibition. As a similar trend was observed in expression levels of inducible nitric oxide synthase (iNOS), we deduced that vegetable soybean leaves may regulate NO synthesis through inhibiting iNOS. We also observed a significant decrease in cyclooxygenase (COX)‐2 gene expression. Analysis of proinflammatory cytokine synthesis revealed that the 70% methanol and 70% ethanol extracts significantly reduced TNF‐α, IL‐6, and IL‐1β synthesis, and increased the intracellular reduced glutathione/oxidized glutathione (GSH/GSSG) ratio from 8 to 12.8. These results indicate that vegetable soybean leaves possess antioxidant activities and exert inhibitory effects on inflammatory mediators, suggesting their potential for use as dietary supplements.

A soy‐based jerky made from transglutaminase‐treated yuba film

“…However, the soybean has a well‐balanced nutrient distribution ratio, which does not adversely affect health (Satusap et al, 2014). Particularly soybeans contain high phytochemical compounds, such as isoflavones and flavonoids (Lin & Wu, 2021). Isoflavones in soybeans are one of the most important phenolic compounds that function as phytoestrogens with potent estrogenic effects and as powerful antioxidants (Lee et al, 2011).…”

Genome-Wide Variation Analysis of Four Vegetable Soybean Cultivars Based on Re-Sequencing

“…The cumulative effect of breeding selection resulted in significant differences in both morphological and quality characteristics between vegetable type and grain type soybeans [ 5 , 6 , 7 ]. To reveal the genome differences between these two types, two vegetable cultivars and two grain cultivars were analyzed by whole-genome re-sequencing simultaneously [ 22 ].…”

“…Due its rich protein, oil, isoflavone, unsaturated fatty acid, vitamins and other nutrients, soybean has become an important crop as both food and forage [ 2 , 3 , 4 ]. Due to the different harvesting times, it can be divided into vegetable type (as fresh vegetable for consumption) and grain type (as raw materials for processing) [ 5 , 6 ]. Vegetable soybean, also named as “Maodou” in China, “Edamame” in Japan, and “Green vegetable soybean” in North America, is a kind of food-grade specialty soybean that could be served as a fresh vegetable, snack, or be used for cooking [ 7 , 8 ].…”

“…Vegetable soybean can either be sold fresh, as pods on the stems, stripped pods, shelled beans, or sold as a frozen or canned product [ 9 , 13 ]. Vegetable soybean has become a very popular vegetable crop worldwide because of its multiple health benefits as well as its economic importance [ 6 , 8 ].…”

Efektivitas pertumbuhan Candida albicans pada media alternatif air rebusan kacang kedelai (Glycine max (l) Merr)

“…Kacang kedelai (Glycine max (L.) Merr) merupakan sumber protein nabati paling populer bagi masyarakat Indonesia pada umumnya (Lin & Wu, 2021). Pengolahan sumber daya alam sebagai pengganti media SGA perlu dilakukan dengan beberapa metode.…”