Composition and taste of beef, pork, and duck meat and bioregulatory functions of imidazole dipeptides in meat.

This study quantified the nutritional components and imidazole dipeptide levels of commercially available meats (beef, pork, and duck), and their effects on taste were quantified via taste recognition devices. Although meat and its products are considered high-risk diets, meat components, such as imidazole dipeptides, exert bioregulatory functions. Further, considering their bioregulatory function, commercial meats' antioxidant activity and vascular endothelial function were examined. Characteristic variations in nutritional components were observed depending on the type and part of meat analyzed. These components affected the taste and texture of meat. The main imidazole dipeptides detected were anserine (duck meat) and carnosine (beef and pork). Meat with larger quantities of total imidazole dipeptide demonstrated better sensory test results. Therefore, anserine and carnosine effects on taste were determined using a taste recognition device; carnosine alone produced a noticeably bitter taste, whereas adding anserine reduced bitterness and enhanced umami taste. In a few cases, cooking enhanced the quantity of carnosine and/or anserine and their antioxidant activities. We demonstrated the ability of imidazole dipeptides, particularly anserine, to improve nitric oxide production in vascular endothelial cells. This study provides essential information for health-conscious consumers to develop high-quality, functional meat products.

Sphingosylphosphorylcholine (SPC), a Causative Factor of SPC-Induced Vascular Smooth Muscle Cells Contraction, Is Taken Up via Endocytosis.

The reaction field of abnormal vascular contraction induced by sphingosylphosphorylcholine (SPC) and the action point of SPC around the plasma membranes remain unknown. However, we found in a previous study that fisetin prevents SPC-induced vascular smooth muscle cells contraction, while the mechanism remains unknown. Therefore, in this study, we aimed to address the action point of SPC around the plasma membranes and the involvement of fisetin. We focused on microdomains and evaluated their markers flotillin-1 and caveolin-1 and the localization of SPC to investigate their action point. The results showed that microdomains of vascular smooth muscle cells were not involved in SPC-induced contraction. However, we found that after SPC had been affected on the plasma membrane, cells took up SPC via endocytosis. Moreover, SPC remained in the cells and did not undergo transcytosis, and SPC-induced contracting cells produced exosomes. These phenomena were similar to those observed in fisetin-treated cells. Thus, we speculated that, although not involved in the reaction field of SPC-induced contractions, the microdomain induced the endocytosis of SPCs, and fisetin prevented the contractions by directly targeting vascular smooth muscle cells. Notably, this preventive mechanism involves the cellular uptake of SPC via endocytosis.

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

Mulberry (Morus australis Poir.) leaves have long been consumed in the form of tea or tincture especially in Asia, owing to their high antioxidant and blood pressure-regulating properties. Although it is thought that vascular abnormal contraction may be involved in the blood pressure-suppressing effect, the effect of mulberry on vascular abnormal contraction is still unknown. Therefore, we investigated mulberry leaves as a potential source of bioactive compounds that prevent vascular abnormal contraction. Mulberry leaves were divided into fresh leaves and tea leaves and further classified according to the age of the tree: more or less than 20 years old, into roasted and unroasted. Mulberry fruits were also evaluated. We assessed the preventive effect of mulberry extracts on vascular abnormal contraction. Extracts from mulberry leaves of trees more than 20 years old showed a strong preventive effect on vascular abnormal contraction of human coronary artery smooth muscle cells. Therefore, to identify the active components in mulberry leaves, we fractionated the active fractions by gel filtration chromatography and reversed-phase high-performance liquid chromatography. The active fraction was further analyzed by mass spectrometry and nuclear magnetic resonance; an active component of the mulberry leaf extract was fisetin. In addition, our results indicated that the hydroxyl group at the C-3 position of fisetin is crucial for its activity. These results prove that fisetin is effective in preventing vascular abnormal contraction. Overall, mulberry leaves and fisetin are expected to be used in a wide range of fields such as functional foods, nutraceuticals, and drug targets.

Effects of flooding cultivation on the composition and quality of taro (Colocasia esculenta cv. Daikichi).

BACKGROUND: Taro (Colocasia esculenta cv. Daikichi) is believed to be one of the earliest cultivated tuber crops and it is a staple food in many parts of the world. The mother corm and side cormels (daughter and granddaughter tubers) form the major consumed parts; however, the former is rarely preferred. Taro is mainly cultivated using either unflooded or flooding cultivation, under dryland-rainfed and wetland-irrigated conditions, respectively. Although flooding cultivation has several advantages, such as lower risk of diseases, weeds, and insect pests, contributing to increased tuber yield, its effects on the quality characteristics of the tubers are largely unknown. In this study, the effects of controlled flooding cultivation on the quality of mother corm and side cormels were investigated. Their taste, color, physical properties, antioxidant activity, and starch, oxalic acid, nitrate ion, arabinogalactan (AG)/AG protein (AGP), γ-aminobutyric acid (GABA), and total polyphenol content was compared with those under unflooded cultivation. RESULTS: Flooding cultivation increased polyphenol levels and antioxidant activity and decreased oxalate, nitrate ion, GABA, and AG/AGP levels. Flooding cultivation also reduced the harshness and increased the hardness and stickiness of steamed mother corm paste, generally discarded under unflooded cultivation, thus rendering it suitable for consumption. CONCLUSION: Controlled flooding cultivation has economic advantages and the potential to improve the quality of cultivated taro. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

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

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.

Dietary Adherence, Self-Efficacy, and Health Behavior Change of WASHOKU-Modified DASH Diet: A Sub-analysis of the DASH-JUMP Study.

BACKGROUND: We previously reported the nutritional characteristics and effects of the DASH-JUMP diet, which is a WASHOKU-modified DASH diet, in Japanese participants with untreated high-normal blood pressure or stage 1 hypertension. The dietary adherence of the DASH diet in Japanese participants has never been evaluated before. OBJECTIVE: We aimed to assess the relationships between dietary adherence, self-efficacy, and health behavior change among study participants who received the DASH-JUMP diet by home delivery. METHODS: Participants were treated with the DASH-JUMP diet for 2 months and consumed their usual diets for the next 4 months. We conducted surveys using the stage of behavior change model questionnaire and the modified perceived health competence scale Japanese version questionnaire at baseline and 1, 2, 3, and 6 months to assess dietary adherence. RESULTS: Forty-three participants (25 men, 18 women; mean age 53.6 ± 8.2 years) returned completed questionnaires, which we analyzed. Health behavior change was motivated by previous behavioral changes and improved biomarkers. The improvement and maintenance of self-efficacy were deeply related to health behavior change and previous self-efficacy. The experience of the DASH-JUMP study for participants included three processes to improve lifestyle habits: Phase 1, reflecting on previous lifestyle habits; Phase 2, learning through new experiences and the acquisition of knowledge; and Phase 3, desiring to maintain their own health. CONCLUSION: It indicated that the DASH-JUMP diet significantly increased self-efficacy and promoted health behavior change.

Catechin and caffeine contents in green tea at different harvest periods and their metabolism in miniature swine.

The catechin content in green tea leaves varies according to cultivation conditions such as intensity of solar radiation, temperature, and precipitation, and thus, there is ambiguity about the best harvest time for obtaining optimal functional effects. In this study, the Yabukita (ordinary) and Benifuki varieties, which contain methylated catechin, were used to determine the difference in green tea catechins according to harvest times and tea manufacturing processes. Caffeine determination was also carried out to provide information about green tea intake for all age-groups of children and pregnant women. Determining the quantity of each catechin was difficult because of degradation, polymerization, and isomerization that had occurred during heat-drying in the refining process. In addition, the absorption of catechin compounds was tested using miniature swine because of their functional and physiological similarity to humans. Benifuki tea leaves contained epigallocatechin-3-(3"-O-methyl) gallate (EGCg3"Me) instead of epigallocatechin-3-(4"-O-methyl) gallate (EGCg4"Me). However, EGCg4"Me was detected during the entire intake period, but EGCg3"Me was not detected in the blood of miniature swine fed Benifuki tea. It is possible that the position of the methyl group was modified by the pig metabolism. Furthermore, caffeine from both Yabukita and Benifuki tea varieties was found to be easily accumulated in miniature swine. These results suggest that nonrefined September-October picking tea (autumn and winter tea) of the Benifuki variety is preferable over the Yabukita variety for consumption by children and pregnant women owing to its lower caffeine content and higher content of methylated catechin.

Elucidating the Improvement in Vascular Endothelial Function from Sakurajima Daikon and Its Mechanism of Action: A Comparative Study with Raphanus sativus.

Vascular diseases, such as myocardial and cerebral infarctions, are the leading causes of death. Some vascular diseases occur as the result of decreases in vascular endothelial function. The innermost layer of the vasculature is formed by vascular endothelial cells (VECs), which are critical for nitric oxide (NO) synthesis. In our search for active constituents in farm products with the potential for improving the vascular system, we examined the effect of Raphanus sativus cv. Sakurajima Daikon on NO production in VECs. In this study, we found that the underlying mechanism for stimulating NO production by Sakurajima Daikon extract involves endothelial-NO-synthase (eNOS) activation by the phosphorylation of Ser1177 and the dephosphorylation of Thr495, which are triggered by elevated concentrations of cytoplasmic Ca2+ resulting from the activation of Ca2+ channels in VECs. We observed that trigonelline, an active constituent of Sakurajima Daikon, improves NO production in VEC cultures.

The Nutritional Characteristics of the Hypotensive WASHOKU-modified DASH Diet: A Sub-analysis of the DASH-JUMP Study.

BACKGROUND: We developed a WASHOKU-modified DASH diet named DASH-JUMP. We previously reported the hypotensive effect of the DASH-JUMP diet in Japanese participants with untreated high-normal Blood Pressure (BP) or stage 1 hypertension. OBJECTIVE: We aim to introduce the DASH-JUMP diet worldwide as a new lifestyle medicine. Accordingly, we prospectively assessed the nutritional characteristics of the DASH-JUMP diet. METHODS: Participants were treated with the DASH-JUMP diet for 2 months. Then, for 4 months after the intervention, they consumed their usual diets. We conducted a nutritional survey using the FFQg nutrient questionnaire at baseline and after 1, 2, 3, and 6 months. We received completed questionnaires from 55 participants (28 men and 27 women; mean age 54.2 ± 8.0 years) and analyzed them. RESULTS: The DASH-JUMP diet is rich in green-yellow vegetables, seaweed, milk, and mushrooms, while it has low contents of meat, eggs, confectionery, oils and fats, pickles, shellfish boiled in sweetened soy sauce, and fruits. Nutrients significantly associated with the observed change in systolic BP were niacin (P = 0.005) and carbohydrate (P = 0.033). The results of the FFQg questionnaire revealed that participants who had an increased BP at 1 month after ceasing the intervention had eating habits that broadly imitated the DASH-JUMP diet at 4 months after ceasing the intervention. Therefore, the systolic and diastolic BP values at 4 months after ceasing the intervention decreased significantly compared to those at baseline. CONCLUSION: The DASH-JUMP diet may represent a new lifestyle medicine for reducing hypertension.

Odour-induced analgesia mediated by hypothalamic orexin neurons in mice.

Various folk remedies employ certain odorous compounds with analgesic effects. In fact, linalool, a monoterpene alcohol found in lavender extracts, has been found to attenuate pain responses via subcutaneous, intraperitoneal, intrathecal, and oral administration. However, the analgesic effects of odorous compounds mediated by olfaction have not been thoroughly examined. We performed behavioural pain tests under odourant vapour exposure in mice. Among six odourant molecules examined, linalool significantly increased the pain threshold and attenuated pain behaviours. Olfactory bulb or epithelium lesion removed these effects, indicating that olfactory sensory input triggered the effects. Furthermore, immunohistochemical analysis revealed that linalool activated hypothalamic orexin neurons, one of the key mediators for pain processing. Formalin tests in orexin neuron-ablated and orexin peptide-deficient mice showed orexinergic transmission was essential for linalool odour-induced analgesia. Together, these findings reveal central analgesic circuits triggered by olfactory input in the mammalian brain and support a potential therapeutic approach for treating pain with linalool odour stimulation.

Effects of the DASH-JUMP dietary intervention in Japanese participants with high-normal blood pressure and stage 1 hypertension: an open-label single-arm trial.

The Dietary Approaches to Stop Hypertension (DASH) diet is recommended by the American Heart Association to lower blood pressure (BP); however, its effects in Japanese participants have not been rigorously studied. We assessed the effects of the DASH-Japan Ube Modified diet Program (DASH-JUMP), a modified DASH diet, on cardiometabolic and inflammatory biomarkers in Japanese participants with untreated high-normal BP or stage 1 hypertension. Fifty-eight participants (30 men and 28 women; mean age 54.1±8.1 years) with untreated high-normal BP or stage 1 hypertension followed the DASH-JUMP (salt 8.0 g per day) for 2 months. After the intervention period, they resumed their usual diets for 4 months. The DASH-JUMP significantly decreased the participants' body mass index values (24.6±3.5 kg m-2 at baseline23.2±3.3 kg m-2 at 2 months, P=0.000), BP (153±14/91±11 mm Hg at baseline130±16/80±9 mm Hg at 2 months, P=0.000 and 139±16/85±10 mm Hg at 6 months, P=0.000), fasting serum glucose level (100±26 mg dl-194±15 mg dl-1 at 2 months, P=0.003) and fasting insulin level (6.9±5.9 µIU ml-14.4±2.7 µIU ml-1 at 2 months, P=0.000). The mean compliance of the participants for the DASH-JUMP diet was 88.5%. The DASH-JUMP diet reduced cardiovascular risk factors and may be an effective nutritional strategy for preventing cardiovascular events.

Sphingosylphosphorylcholine induces stress fiber formation via activation of Fyn-RhoA-ROCK signaling pathway in fibroblasts.

Sphingosylphosphorylcholine (SPC), a bioactive sphingolipid, has recently been reported to modulate actin cytoskeleton rearrangement. We have previously demonstrated Fyn tyrosine kinase is involved in SPC-induced actin stress fiber formation in fibroblasts. However, Fyn-dependent signaling pathway remains to be elucidated. The present study demonstrates that RhoA-ROCK signaling downstream of Fyn controls stress fiber formation in SPC-treated fibroblasts. Here, we found that SPC-induced stress fiber formation was inhibited by C3 transferase, dominant negative RhoA or ROCK. SPC activated RhoA, which was blocked by pharmacological inhibition of Fyn activity or dominant negative Fyn. Constitutively active Fyn (ca-Fyn) stimulated stress fiber formation and localized with F-actin at the both ends of stress fibers, both of which were prevented by Fyn translocation inhibitor eicosapentaenoic acid (EPA). In contrast, inhibition of ROCK abolished only the formation of stress fibers, without affecting the localization of ca-Fyn. These results allow the identification of the molecular events downstream SPC in stress fiber formation for a better understanding of stress fiber formation involving Fyn.

Solid-state NMR analysis of the orientation and dynamics of epigallocatechin gallate, a green tea polyphenol, incorporated into lipid bilayers.

Catechins are the principle polyphenolic compounds in green tea; the four major compounds identified are epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECg) and epigallocatechin gallate (EGCg). Tea catechins tend to attach externally to their targets, such as viral envelopes, cell membranes, or the surface of low-density lipoproteins. In order to further our understanding of the molecular mobility of these compounds in cells, we examined the interaction of tea catechins with lipid membranes using solid-state NMR techniques. Our previous work indicated that the EGCg molecule is incorporated into lipid bilayers in a unique orientation. However, the detailed configuration, orientation, and dynamics of EGCg in lipid bilayers have not been well-characterized. Here, we investigated the orientation and dynamics of EGCg incorporated into multi-lamellar vesicles (MLVs) and bicelles using solid-state NMR spectroscopy.

Involvement of Fyn tyrosine kinase in actin stress fiber formation in fibroblasts.

Lysophosphatidic acid (LPA) and sphingosylphosphorylcholine (SPC) activated Fyn tyrosine kinase and induced stress fiber formation, which was blocked by pharmacological inhibition of Fyn, gene silencing of Fyn, or dominant negative Fyn. Overexpressed constitutively active Fyn localized at both ends of F-actin bundles and triggered stress fiber formation, only the latter of which was abolished by Rho-kinase (ROCK) inhibition. SPC, but not LPA, induced filopodia-like protrusion formation, which was not mediated by Fyn and ROCK. Thus, Fyn appears to act downstream of LPA and SPC to specifically stimulate stress fiber formation mediated by ROCK in fibroblasts.

Direct evidence of interaction of a green tea polyphenol, epigallocatechin gallate, with lipid bilayers by solid-state Nuclear Magnetic Resonance.

The interaction of a tea catechin, epigallocatechin gallate (EGCg), with the model membrane of dimyristoylphosphatidylcholine (DMPC) was studied by solid-state (31)P and (2)H NMR. The (31)P chemical shift anisotropy of the DMPC phosphate group decreased on addition of EGCg. The (2)H NMR spectrum of [4-(2)H]EGCg, which is deuterated at the 4-position, in the DMPC liposomes gave deuterium nuclei with much smaller quadrupole splittings than those in the solid phase. These (31)P and (2)H NMR observations provide direct experimental evidence that the EGCg molecule interacts with the lipid bilayers.

Relationship between antibacterial activity of (+)-catechin derivatives and their interaction with a model membrane.

(+)-Catechin derivatives with different alkyl chain lengths were synthesized from (+)-catechin and various straight chain alkylaldehydes in the presence of methyl mercaptan, and their antibacterial activities against Gram-positive bacteria were evaluated. The antibacterial activity increased markedly with elongation of the alkyl chain lengths of the derivatives and reached a maximum at a chain of four to seven carbons. Subsequently, interaction of the (+)-catechin derivatives with a model membrane using liposome was investigated. The derivatives with a chain of three carbons or more were found to have very strong affinity for the membrane. The injury action of the derivatives against the membrane was examined with liposome in which calcein was enclosed as a fluorescent indicator. The leakage was observed in the derivatives with chain lengths of four carbons or more. Particularly the derivatives with chains longer than five carbons are considered to destroy the liposome membrane judging from the degree of the fluorescent leakage. These results implied that the lipophilicity and disrupting ability of the (+)-catechin derivatives to the liposome membrane participate in their antibacterial activity.

Effect of quercetin conjugates on vascular permeability and expression of adhesion molecules.

Quercetin and its glucosides exist in plant foods and are recovered in human plasma as glucuronide and sulfate conjugates. Quercetin and its conjugates show antioxidant activity in model experiments. It remains obscure, however, whether these conjugates retain these biological functions in vivo. We investigated the interaction of quercetin conjugates with lipid bilayers using liposome systems. Less quercetin conjugate was incorporated into liposomes than quercetin aglycone. We also studied the vascular permeability of quercetin-3-glucuronide using cell culture inserts. Incubation of human aortic endothelial cells (HAECs) with IL-1alpha resulted in increased permeability of quercetin-3-glucuronide. Furthermore, quercetin-3-glucuronide showed no suppressive effect on TNF-alpha-induced cell expression of intercellular adhesion molecule-1 (ICAM-1) on HAECs. These observations suggest that circulating conjugates of quercetin pass through the endothelium to reach vascular smooth muscle cells and exert their biological effects in the blood vessels during inflammation followed by deconjugation of the conjugates.

Affinity of isoflavonoids for lipid bilayers evaluated with liposomal systems.

Three parameters, i.e., the proportion of the amount incorporated into the liposomes, the partition coefficient in a system of n-octanol/phosphate buffered saline, and the retention times by HPLC, were measured to determine the lipophilicity of isoflavonoids. The presence of a hydroxyl group at 5-position of the A-ring and a methoxyl group at 4'-position of the B-ring in the isoflavonoid structure increased the three parameters. The localization of isoflavonoids in lipid bilayers was investigated by a liposome system with fluorescent probes. The location of the isoflavonoid depended on its structure. The cytotoxicity of isoflavonoids was investigated by a colony-formation assay with Chinese hamster lung fibroblast V79 cells. The structure-activity relationship of the cytotoxic activity partly reflected those of the three parameters. This suggests that the biological activities of isoflavonoids in vitro could be attributable to their affinity for lipid components in the cases where the estrogen receptors have no role.