Characteristic Analysis of Trigonelline Contained in Raphanus sativus Cv. Sakurajima Daikon and Results from the First Trial Examining Its Vasodilator Properties in Humans

Abstract

Vascular disease poses a major public health problem worldwide. Trigonelline isolated from Raphanus sativus cv. Sakurajima Daikon (Sakurajima radish) induces nitric oxide production from vascular endothelial cells and enhances vascular function. Here, we investigated the characteristics of trigonelline and its effects on endothelial function after consumption of Sakurajima radish by humans. Our results show that Sakurajima radish contains approximately 60 times more trigonelline than other radishes and squashes. Additionally, no significant differences were observed between varieties of Sakurajima radish, suggesting that any type of Sakurajima radish can be ingested for trigonelline supplementation. The effects of cooking and processing Sakurajima radish were also evaluated, as were the effects of freezing, and changes in osmotic pressure and pH. A first-in-human trial using Sakurajima radish showed that ingestion of 170 g/day of Sakurajima radish for ten days increased blood trigonelline concentrations and significantly improved flow-mediated dilation, which is a measure of vascular endothelial function. Overall, our findings suggest that the trigonelline contained in Sakurajima radish may contribute to improved human vascular endothelial function. Hence, Sakurajima radish may enhance vascular endothelial function as a functional food.

Fisetin, a major component derived from mulberry (Morus australis Poir.) leaves, prevents vascular abnormal contraction

“…However, the preventive effect decreased when the mulberry leaves were roasted and when mulberry leaf extract was not added at the time of contraction despite exposure to mulberry leaves for a long time (60 h). The difference in the preventive effects of roasted and unroasted tea leaves can be attributed to the effect of the roasting process; for example, it is known that iminosaccharides 29 and trigonelline 11 are degraded during the roasting process and that high‐temperature drying decreases the antioxidant activity of mulberry leaves. 30 Therefore, roasting may have affected the degradation of key components of mulberry leaves.…”

“… 7 , 8 For example, antioxidants in red wine have been suggested to have a functional effect on blood vessels. 9 Various other foods have been reported to regulate physiological functions, such as the vascular endothelial function‐improving effects of Sakurajima daikon ( Raphanus sativus “Sakurajima Daikon”) 10 , 11 and the antioxidant effects of Capsicum annuum . 12 Mulberry ( Morus australis Poir.)…”

Special Issue “Dietary (Poly)Phenols and Health”

“…I am pleased that 19 papers published in this Special Issue [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ], present novel findings and adhere to the above-mentioned current trends. I personally consider the fact, that some papers in this issue also reported negative or only mild effects of the tested compounds to be very important as well.…”

“…Human interventional studies published in this Special Issue included: (a) a study that found that riceberry rice bread rich in anthocyanins caused a significantly lower postprandial glucose peak in comparison to Hom Mali bread [ 11 ] and similarly, a polyphenol-rich functional food breakfast caused a lower glucose peak than ready-to-eat breakfast cereal [ 14 ]; (b) a comparison of the effect of beverages enriched with phenol-rich extracts from apple, blueberry, and coffee berry on cognition and mood [ 13 ]; (c) a study that found that Sakurajima radish administration did not reduce arterial blood pressure but showed a tendency to decrease heart rate [ 21 ]. An epidemiological study suggested, that intake of two groups of polyphenols (stilbenes and flavonoids) was associated with lower obesity prevalence.…”

Pharmacological Activities, Therapeutic Effects, and Mechanistic Actions of Trigonelline

“…Ingestion of TRG-enriched Sakurajima radish (170 g/day, for 10 days) increased the plasma TRG levels and improved flow-mediated dilation, an index of vascular endothelial function [ 80 ].…”