DA-6 improves sunflower seed vigor under Al3+ stress by regulating Al3+ balance and ethylene metabolic.

Aluminum (Al3+) stress restricts plant seed germination and seedling growth seriously. Here, the sunflower "S175″ variety was used to explore the technique of improving seed vigor under Al3+ stress and investigate the effect of diethyl aminoethyl hexanoate (DA-6) on physiological characteristics in sunflower seeds during germination under Al3+ stress. The results showed that 3.0 mmol·L-1 Al3+ treatment significantly suppressed the sunflower seed germination and seedling growth. Al3+ stress significantly increased Al3+ content and secretion rates of citric and malic acids in sunflower seeds during germination. Besides, endogenous ethylene content was increased in Al3+-treated seeds. DA-6 serves as a positive signal to regulate the sunflower seed germination under Al3+ stress. Moreover, DA-6 enhanced the activities of malic dehydrogenase, citrate synthase, and isocitrate dehydrogenase, up-regulated the expressions of organic acid transport-related genes (ALMT and MATE), resulting in reduced accumulation of Al3+. Furthermore, exogenous DA-6 mitigated excessive accumulation of ethylene by decreasing the 1-aminocyclopropane-1-dihydrodipicolinate synthase activity and related-gene expression. However, DA-6 treatment had no effect on abscisic acid or gibberellin metabolism in sunflower seeds under Al3+ stress. These results confirmed that DA-6 application enhanced the germination capacity through induction of the synthesis and transport of malic and citric acids, and suppression of the excessive accumulation of endogenous ethylene, thus contributing to alleviate Al3+ toxicity in sunflower seeds.

Analysis of Proanthocyanidins in Plant Materials Using Hydrophilic Interaction HPLC-QTOF-MS.

Proanthocyanidins (PACs) have been proven to possess a wide range of biological activities, but complex structures limit their study of structure-function relationships. Therefore, an efficient and general method using hydrophilic interaction high-performance liquid chromatography coupled with high-resolution quadrupole time-of-flight tandem mass spectrometry (HILIC-QTOF-MS) was established to analyze PACs from different plant materials. This method was successfully applied to characterize PACs from Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves (BLPs), sorghum testa (STPs) and grape seeds (GSPs). BLPs with the degree of polymerization (DP) from 1 to 8 were separated. BLPs are mainly B-type prodelphinidins and A-type BLPs were first found in this study. STPs and GSPs belonging to procyanidins showed DP from 3 to 11 and 2 to 12, respectively. A-type linkages were found for every DP of STPs and GSPs, which were first found. These results showed that HILIC-QTOF-MS can be successfully applied for analyzing PACs from different plant materials, which is necessary for the prediction of their potential health benefits.

Mainly Dimers and Trimers of Chinese Bayberry Leaves Proanthocyanidins (BLPs) are Utilized by Gut Microbiota: In Vitro Digestion and Fermentation Coupled with Caco-2 Transportation.

Chinese bayberry leaf proanthocyanidins (BLPs) are Epigallocatechin gallate (EGCG) oligomers or polymers, which have a lot of health-promoting activity. The activity is closely related to their behavior during in vitro digestion, which remains unknown and hinders further investigations. To clarify the changes of BLPs during gastrointestinal digestion, further research is required. For in vitro digestion, including gastric-intestinal digestion, colon fermentation was applied. Caco-2 monolayer transportation was also applied to investigate the behavior of different BLPs with different degrees of polymerization. The trimers and the tetramers were significantly decreased during in vitro gastric-intestinal digestion resulting in a significant increase in the content of dimers. The dimers and trimers were the main compounds utilized by gut microbiota and they were assumed not to degrade through cleavage of the inflavan bond. The monomers and dimers were able to transport through the Caco-2 monolayer at a rate of 10.45% and 6.4%, respectively.

Phenolic Compositions and Antioxidant Activities Differ Significantly among Sorghum Grains with Different Applications.

Sorghum grains with different applications had different phenolic profiles, which were corresponded to various antioxidant capacities. In this study, total phenolic, proanthocyanidins and flavonoids contents, as well as contents of individual phenolic compounds from sorghum grains with various applications were determined, and their antioxidant capacities were evaluated. Total phenolic contents (TPC) and total proanthocyanidins contents (TPAC) showed strong correlation with antioxidant activities (r > 0.95, p < 0.01). Hongyingzi (S-1), one of the brewing sorghums, showed the highest level of TPC and TPAC, while white grain sorghum (S-8) had the lowest. Except for black grain sorghum (S-7), that contained the highest contents of ferulic acid, brewing sorghum grains contained the higher contents of the most individual phenolic compounds, especially the variety S-1. The correlation among individual phenolic compounds and antioxidant activities indicated that the free forms of protocatechuic acid (r = 0.982 of FRAPassay, p < 0.01) and taxifolin (r = 0.826 of FRAP assay, p < 0.01) may be the main functional compounds. These results indicate that brewing sorghum grains can also be utilized as effective materials for functional foods.

Antidepressant-like effects of hyperoside on chronic stress-induced depressive-like behaviors in mice: Gut microbiota and short-chain fatty acids.

BACKGROUND: The antidepressant effect of hyperoside (HYP), which is the main component of Hypericum perforatum, is not established. This study aimed to determine the effects of HYP on depression. METHODS: The antidepressant-like effect of HYP was studied in mice induced by chronic restraint stress (CRS). The effects of HYP on behavior, inflammation, neurotransmitters, gut microbiota, and short-chain fatty acids (SCFAs) were studied in CRS mice. RESULTS: HYP improved depressive-like behavior in mice induced by CRS. Nissl staining analysis showed that HYP improved neuronal damage in CRS mice. Western blot (WB) analysis showed that HYP increased the expression levels of BDNF and PSD95 in the hippocampus of CRS mice. The results of ELISA showed that HYP down-regulated the expression levels of IL-6, IL-1ß, TNF-α, and CORT in the hippocampus, blood, and intestinal tissues of mice and up-regulated the expression levels of 5-HT and BDNF. Hematoxylin and eosin (HE) staining results indicate that HYP can improve the intestinal histopathological injury of CRS mice. The results of 16S rRNA demonstrated that HYP attenuated the dysbiosis of the gut microbiota of depressed mice, along with altering the concentration of SCFAs. LIMITATIONS: In the present study, direct evidence that HYP improves depressive behaviors via gut microbiota and SCFAs is lacking, and only female mice were evaluated, which limits the understanding of the effects of HYP on both sexes. CONCLUSIONS: HYP can improve CRS-induced depressive-like behaviors in mice, which is associated with regulating the gut microbiota and SCFAs concentration.

Antioxidant and pancreatic lipase inhibitory effects of flavonoids from different citrus peel extracts: An in vitro study.

Obesity and oxidative damage are two important risk factors associated closely with metabolic syndrome. Utilization of functional food ingredients is considered as a feasible way to tackle these challenges. In the present study, eight representative species of citrus peel extracts (CPEs) were evaluated and compared for their flavonoid profiles, antioxidant activities, and pancreatic lipase (PL) inhibitory capacities and mechanisms. Results indicated that hesperidin, naringin, neohesperidin, narirutin and eriocitrin were the five major flavonoids in CPEs, among which hesperidin was the main active PL inhibitor. Moreover, hesperidin could interact with PL by hydrogen bonds and van der Waals forces, and the interaction would not obviously change the secondary structure of PL. Overall, ponkan peel extract, having the strongest overall antioxidant activity, the highest content of hesperidin and total phenolic compounds among all tested CPEs, is a promising natural ingredient to scavenge free radicals and manage obesity.