Mannoproteins modulate olfactrory perception and copigmentation of organoleptic-active-components in wines: Effects and potential molecular mechanisms.

In this research, accelerated aroma release experiments and malvidin-3-O-glucoside copigmentation experiments in model red wine solutions were designed to investigate the abilities and molecular mechanisms of mannoproteins in modulating olfactory/chromatic properties of red wines. Results indicate that under orthonasal condition, mannoprotein MP2 was promising aroma modulator due to its predictable behaviors in expelling and retaining the aroma compounds during different periods. Low field nuclear magnetic resonance and molecular dynamic simulation proved that the modulation ability of MP2 should be explained by its transitionary interacting preferences with water/aroma compound molecules. Retronasal results show that the release of aroma compounds and olfactory perceptions were irregular and difficult to predict, probably due to the complexity of the retronasal condition. All mannoproteins protected malvidin-3-O-glucoside and quercetin via the formation of binary/ternary complexes, and quercetin was found prior to be protected than malvidin-3-O-glucoside. Principal mannoprotein A0A6C1DV26 might be the critical malvidin-3-O-glucoside protector. With the presence of quercetin, principal mannoproteins B3LQU1/B5VL26 in mannoprotein MP1 might exhibit intramolecular and/or intermolecular mechanisms that strengthened the hyperchromic effect, thus enhanced the copigmentation.

Efficacy and Safety of Pregabalin and Gabapentin for Pruritus: A Systematic Review and Meta-Analysis.

CONTEXT: Limited data existed on the efficacy and safety of novel antiepileptic drugs (pregabalin and gabapentin) in treating pruritus. OBJECTIVES: To assess their role in managing either acute or chronic pruritus. METHODS: A systematic search was conducted in PubMed, EMBASE, the Cochrane Library, and Web of Science databases for relevant randomized controlled trials. Pooled odd ratio (OR) with 95% CI were performed using RevMan5.4 and R4.3.1. RESULTS: Analysis of 27 articles involving 2,016 patients showed significant reduction in pruritus incidence (OR, 0.30 [CI, 0.22-0.4]; I2=1%) and improvements in VAS (MD, 2.76 [CI, 0.95-4.57]; I2=98%) and 5-D scores (MD, 3.42 [CI, 2.10-4.75]; I2=92%) with pregabalin/gabapentin compared to controls. Adverse effects mainly included dizziness, somnolence, nausea and vomiting, dry mouth, constipation, and anxiety, with no significant difference between the groups (OR, 1.08 [CI, 0.32-3.59]; I2=76%). CONCLUSION: The novel antiepileptic drugs pregabalin and gabapentin demonstrated significant therapeutic value in the treatment of pruritus, with a favorable safety profile. Compared to commonly used pruritus treatments such as antihistamines and antidepressants, these medications offered a promising alternative.

Organoleptic modulation functions and physiochemical characteristics of mannoproteins: Possible correlations and precise applications in modulating color evolution and orthonasal perception of wines.

Mannoproteins have traditionally been recognized as effective wine organoleptic modulators, however, ambiguous understanding of the relationship between their organoleptic functions and physiochemical characteristics often lead to inappropriate application in winemaking. To reveal the possible role the physiochemical characteristics of mannoproteins play in modulating wine color and aroma properties, three water-soluble mannoproteins (MP1, MP2, MP3) with different physiochemical characteristics have been prepared, and accelerated red wine aging, malvidin pigments formation experiments, accelerated aroma release experiments have been designed to observe their organoleptic modulating functions in this research. Results suggest that the phenolic/chromatic stability of red wines could be enhanced by MP3, probably due to its low steric hindrance potential, high reactivity, and good hydro-alcoholic stability conferred by its high Mannan/Glucan ratio (8.68), abundant hydrophobic/hydrophilic amino acids (65.29 % of total protein), and low/medium molecular weight level (30.71-57.77 kDa), respectively, which protected the phenolic compounds and promoted the formation of pyranoanthocyanins. Mannoproteins could modulate the volatility of aroma compounds by expelling or retention effects, which depended on the duration of mannoprotein application (the expelling effect was firstly observed possibly because of the significant adsorption of free H2O by MPs) and the types of mannoproteins. MP1 and MP2 were prone to retain and expel aroma compounds, respectively, probably due to their medium/high molecular weight levels (60.48-135.39 kDa) that conferred abundant interacting sites, and the high proportion of hydrophobic and hydrophilic components in MP1 (97.71 % polysaccharides of total mannoprotein, 34.58 % hydrophobic amino acids of total protein) and MP2 (97.96 % polysaccharides of total mannoprotein, 28.36 % hydrophobic amino acids of total protein) guaranteed a relatively higher interacting frequency with aroma compounds and free H2O molecules, respectively.