Increased Intestinal Absorption of Vitamin U in Steamed Graviola Leaf Extract Activates Nicotine Detoxification.

Graviola leaves contain much vitamin U (vit U), but their sensory quality is not good enough for them to be developed as food ingredients. Addition of excipient natural ingredients formulated alongside vit U as active ingredients could enhance not only its sensory quality but also its bioavailability. The objectives of this study were to measure the bioaccessibility and intestinal cellular uptake of bioactive components, including rutin, kaempferol-rutinoside, and vit U, from steamed extract of graviola leaves (SGV) and SGV enriched with kale extract (SGK), and to examine how much they can detoxify nicotine in HepG2 cells. The bioaccessibility of vit U from SGV and SGK was 82.40% and 68.03%, respectively. The cellular uptake of vit U in SGK by Caco-2 cells was higher than that in SGV. Cotinine content converted from nicotine in HepG2 cells for 120 min was 0.22 and 0.25 µg/mg protein in 50 µg/mL of SGV and SGK, respectively, which were 2.86 and 3.57 times higher than the no-treatment control. SGK treatment of HepG2 cells upregulated CYP2A6 three times as much as did that of SGV. Our results suggest that graviola leaf extract enriched with excipient ingredients such as kale could improve vit U absorption and provide a natural therapy for detoxifying nicotine.

Betaine or folate can equally furnish remethylation to methionine and increase transmethylation in methionine-restricted neonates.

Methionine partitioning between protein turnover and a considerable pool of transmethylation precursors is a critical process in the neonate. Transmethylation yields homocysteine, which is either oxidized to cysteine (i.e., transsulfuration), or is remethylated to methionine by folate- or betaine- (from choline) mediated remethylation pathways. The present investigation quantifies the individual and synergistic importance of folate and betaine for methionine partitioning in neonates. To minimize whole body remethylation, 4-8-d-old piglets were orally fed an otherwise complete diet without remethylation precursors folate, betaine and choline (i.e. methyl-deplete, MD-) (n=18). Dietary methionine was reduced from 0.3 to 0.2 g/(kg∙d) on day-5 to limit methionine availability, and methionine kinetics were assessed during a gastric infusion of [13C1]methionine and [2H3-methyl]methionine. Methionine kinetics were reevaluated 2 d after pigs were rescued with either dietary folate (38 µg/(kg∙d)) (MD + F) (n=6), betaine (235 mg/(kg∙d)) (MD + B) (n=6) or folate and betaine (MD + FB) (n=6). Plasma choline, betaine, dimethylglycine (DMG), folate and cysteine were all diminished or undetectable after 7 d of methyl restriction (P<.05). Post-rescue, plasma betaine and folate concentrations responded to their provision, and homocysteine and glycine concentrations were lower (P<.05). Post-rescue, remethylation and transmethylation rates were~70-80% higher (P<.05), and protein breakdown was spared by 27% (P<.05). However, rescue did not affect transsulfuration (oxidation), plasma methionine, protein synthesis or protein deposition (P>.05). There were no differences among rescue treatments; thus betaine was as effective as folate at furnishing remethylation. Supplemental betaine or folate can furnish the transmethylation requirement during acute protein restriction in the neonate.