Pharmacokinetic Parameters of Watermelon (Rind, Flesh, and Seeds) Bioactive Components in Human Plasma: A Pilot Study to Investigate the Relationship to Endothelial Function
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
Authors: Fan, Jiayi; Park, Eunyoung; Zhang, Liyun; Edirisinghe, Indika; Burton-Freeman, Britt; Sandhu, Amandeep K.
Abstract
This study aimed to investigate the metabolic fate of bioactive components in watermelon and explore their effect on endothelial function. Six healthy overweight/obese (BMI: 28.7 +/- 1.6 kg/m(2)) adults received 100 kcal of watermelon flesh (WF), rind (WR), seeds (WS), or control meal. L-Citrulline, arginine, and (poly)phenolic metabolites were characterized in plasma over 24 h using UHPLC-MS. Endothelial function was assessed using a flow mediated dilation (FMD) technique over 7 h. Maximum concentration (C-max) and area under the curve (AUC(0-8h)) of L-citrulline were significantly higher after WF- and WR-containing test meals compared to control (p < 0.05). Likewise, several individual phenolic metabolites in plasma had significantly higher C-max after WR, WF, or WS intake compared to control. FMD responses were not different among test meals. Our results provide insights on circulating metabolites from watermelon flesh, seed, and rind and lay the foundation for future clinical trials on vascular benefits of watermelon.
The diversification and lineage-specific expansion of nitric oxide signaling in Placozoa: insights in the evolution of gaseous transmission
SCIENTIFIC REPORTS
Authors: Moroz, Leonid L.; Romanova, Daria Y.; Nikitin, Mikhail A.; Sohn, Dosung; Kohn, Andrea B.; Neveu, Emilie; Varoqueaux, Frederique; Fasshauer, Dirk
Abstract
Nitric oxide (NO) is a ubiquitous gaseous messenger, but we know little about its early evolution. Here, we analyzed NO synthases (NOS) in four different species of placozoans-one of the early-branching animal lineages. In contrast to other invertebrates studied, Trichoplax and Hoilungia have three distinct NOS genes, including PDZ domain-containing NOS. Using ultra-sensitive capillary electrophoresis assays, we quantified nitrites (products of NO oxidation) and l-citrulline (co-product of NO synthesis from l-arginine), which were affected by NOS inhibitors confirming the presence of functional enzymes in Trichoplax. Using fluorescent single-molecule in situ hybridization, we showed that distinct NOSs are expressed in different subpopulations of cells, with a noticeable distribution close to the edge regions of Trichoplax. These data suggest both the compartmentalized release of NO and a greater diversity of cell types in placozoans than anticipated. NO receptor machinery includes both canonical and novel NIT-domain containing soluble guanylate cyclases as putative NO/nitrite/nitrate sensors. Thus, although Trichoplax and Hoilungia exemplify the morphologically simplest free-living animals, the complexity of NO-cGMP-mediated signaling in Placozoa is greater to those in vertebrates. This situation illuminates multiple lineage-specific diversifications of NOSs and NO/nitrite/nitrate sensors from the common ancestor of Metazoa and the preservation of conservative NOS architecture from prokaryotic ancestors.