Fruit Quercetin Research Articles

Nonlinear molecular dynamics of quercetin in Gynocardia odorata and Diospyros malabarica fruits: Its mechanistic role in hepatoprotection.

Liver performs number of critical physiological functions in human system. Intoxication of liver leads to accumulation of free radicals that eventually cause damage, fibrosis, cirrhosis and cancer. Carbon tetrachloride (CCl4) belongs to hepatotoxin is converted to a highly reactive free radical by cytochrome P450 enzymes that causes liver damage. Plant extracts derived quercetin has substantial role in hepatoprotection. This study highlights the possible mechanism by which quercetin plays significant role in hepatoprotection. HPLC analysis revealed the abundance of quercetin in the fruit extracts of Gynocardia odorata and Diospyros malabarica, were isolated, purified and subjected to liver function analysis on Wistar rats. Post quercetin treatment improved liver function parameters in the hepatotoxic Wistar rats by augmenting bilirubin content, SGOT and SGPT activity. Gene expression profile of quercetin treated rats revealed down regulation of HGF, TIMP1 and MMP2 expressed during CCl4 induction. In silico molecular mechanism prediction suggested that quercetin has a high affinity for cell signaling pathway proteins BCL-2, JAK2 and Cytochrome P450 Cyp2E1, which all play a significant role in CCl4 induced hepatotoxicity. In silico molecular docking and molecular dynamics simulation have shown that quercetin has a plausible affinity for major signaling proteins in liver. MMGBSA studies have revealed high binding of quercetin (ΔG) -41.48±11.02, -43.53±6.55 and -39.89±5.78 kcal/mol, with BCL-2, JAK2 and Cyp2E1, respectively which led to better stability of the quercetin bound protein complexes. Therefore, quercetin can act as potent inhibitor against CCl4 induced hepatic injury by regulating BCL-2, JAK2 and Cyp2E1.

Nafion-MWCNT composite modified graphite paste for the analysis of quercetin in fruits of Acanthopanax sessiliflorus

Abstract The Nafion multi-walled carbon nanotube composite modified graphite paste electrode (Nafion/MWCNT-GPE) was investigated for electrocatalytic oxidation of quercetin in 0.1 mol L −1 citric–NaOH buffer (pH = 3.7) and in 20% methanol solution. This was performed by cyclic voltammetry, electrochemical impedance spectrometry (EIS) and square-wave anodic stripping voltammetry (SWASV) techniques. Quercetin shows a reversible electron transfer at the modified electrode in potential range of −0.1 V to 0.6 V. Results indicated that the electrode process was diffusion limiting. The optimum parameters for SWASV deposition condition were purging time 4 min, deposition time 150 s, deposition potential 0.0 V, pulse amplitude 40 mV, step potential 6 mV and frequency 50 Hz. At optimal conditions, the content of quercetin was found to be 2.89 mg g −1 and 4.21 mg g −1 in dry and frozen fruits of Acanthopanax sessiliflorus ( A. sessiliflorus ) respectively with recoveries on the quercetin in dry 99.4% and frozen 99.2% ( n = 5). The SWASV method with the Nafion/MWCNT-GPE is proven to be a viable technique for determining quercetin in fruits of A. sessiliflorus samples.

Anthocyanin indexes, quercetin, kaempferol and myricetin concentration in leaves and fruit ofAbutilon theophrastiMedik. genetic resources

Anthocyanin indexes, quercetin, kaempferol and myricetin may provide industry with potential new medicines or nutraceuticals. Velvetleaf (Abutilon theophrastiMedik) leaves from 42 plant introductions (PI) were analyzed for anthocyanin indexes while both leaves and fruit were used for quercetin, kaempferol and myricetin concentration analysis by reverse-phase high performance liquid chromatography. Leaf anthocyanin indexes ranged from 6.15 to 11.25 among PI. Leaf quercetin and kaempferol concentrations ranged from 1.50 to 4.79 mg/g and 0.43 to 2.17 mg/g, respectively. Fruit quercetin, kaempferol and myricetin concentrations ranged from 0.061 to 0.266 mg/g, 0.054 to 0.734 mg/g, and 0 to 35.87 μg/g, respectively. Significant differences in leaf weight were also observed. Significant correlations were found between several traits. This information regarding anthocyanin indexes, quercetin, kaempferol and myricetin concentrations will be useful for velvetleaf cultivar development. Breeders and other scientists could use this germplasm that contains high concentrations of anthocyanins, quercetin, kaempferol and myricetin to develop new medicines or nutraceuticals from an extremely useful weedy species.