Inhibitory effects of polyphenols from water chestnut (Trapa japonica) husk on glycolytic enzymes and postprandial blood glucose elevation in mice

Abstract

Water chestnut is an annual aquatic plant that grows in Asia and Europe. Although water chestnut has been used as food and herbal medicine, its physiological functions and active ingredients are unknown. Here, we extracted polyphenols from the husk of the Japanese water chestnut (Trapa japonica) and assessed their effects on blood glucose levels. Three hydrolysable polyphenolics (WCPs), eugeniin, 1,2,3,6-tetra-O-galloyl-β-d-glucopyranose, and trapain, were predominant with dry-weight contents of 2.3 ± 0.0, 2.7 ± 0.1, and 1.2 ± 0.1g/100g, respectively. These WCPs exhibited inhibitory activity against α-amylase and α-glucosidase. Whereas (-)-epigallocatechin gallate does not inhibit α-amylase, WCPs exhibited high inhibitory activity (>80% at 0.15 mg/mL). In mice, administration of WCPs (40 mg/kg) significantly reduced blood glucose and serum insulin levels as assessed by the carbohydrate tolerance test.

DNA scission inhibition, antioxidant, and antiproliferative activities of water chestnut (Trapa natans) extracted in different solvents

“…So, the extractions with methanol resulted in the highest amount of the total extractable compounds than in the remaining solvents, which is in agreement with the report of Ao, Li, Elzaawely, Xuan, & Tawata (2008). Midori et al (2014) also confirmed the presence of polyphenols in water-chestnut husk.…”

“…The sample solution showed antiproliferative activity against Colo-205, T47D, and MCF7 and it significantly reduced the growth rate of cancer cells at a concentration of 50 µg/mL after 24 h treatment, however, the maximum effect was on Colo-205, as shown in Figure 5. The presence of various bioactive compounds like glycosides, flavonoids, phytosterols, and tannins (Shalabh et al, 2012) in the extract of T. natans and the polyphenols like trapain, euginin, and 1,2,3,6-tetra-O-galloyl-beta-D-glucopyranose (TGG) reported by Midori et al (2014) in the husk of T. natans may be responsible for anticancerous activities (Li et al, 2013;Ravishankar, Rajora, Greco, & Osborn, 2013). Yuan and Walsh (2006) reported dose-dependent inhibition against the proliferation of the human cervical epithelial adenocarcinoma HeLa cell line in the case of dulse and kelp extracts, which also have aquatic habitats as water chestnut.…”

Wheat-water chestnut flour blends: effect of baking on antioxidant properties of cookies

“…Water chestnut extracts are also reported to have high inhibitory activity against glycolytic enzymes such as aamylase that inhibits blood glucose elevation and a unique feature of reducing insulin secretion and hence can be effective food additives in managing type 2-diabetes (Yasuda et al 2014).…”

<i>Trapa japonica</i> Flerov Extract Attenuates Lipid Accumulation through Downregulation of Adipogenic Transcription Factors in 3T3-L1 Cells

“…The fruit contains approximately 80% starch, 5% protein, and a significant amount of vitamins [19]. The recent investigation revealed polyphenols, eugeniin, 1,2,3,6-tetra-O-galloyl-β-d-glucopyranose, and trapain from the husk of the TJF [20]. Most studies evaluating TJF have focused on its taxonomy and ecology [18] [21].…”

“…Most studies evaluating TJF have focused on its taxonomy and ecology [18] [21]. TJF has been known to have anti-oxidative, anti-cancer and anti-diabetic effects, reduction of blood glucose levels, and inhibitory activity against α-amylase and α-glucosidase [20] [22]- [24]; however, the effects of TJF on anti-adipogenesis have not been investigated yet. In the present study, we examined whether TJF extract affects adipocyte differentiation, and the expression of adipogenic transcription factors and related proteins in 3T3-L1 cells.…”