Presence Of Isorhamnetin Research Articles

Isorhamnetin at Physiologically Attainable Nanomolar Concentrations Inhibits Adipocyte differentiation and Lipid Droplet Accumulation in vitro

Differentiation of preadipocytes into adipocytes is a major step leading to obesity. This study examines the effects of isorhamnetin, a metabolite of quercetin, at physiological and supraphysiological concentrations on the differentiation of 3T3-L1 pre-adipocyte to adipocyte. Comparison was made with the effect of quercetin on 3T3-L1 differentiation under the same conditions. Cell viability during adipocyte differentiation for 8 days in the presence of isorhamnetin and quercetin was above 94% and 97%, respectively. Oil Red O staining showed significant differences (P < 0.05) between the effect of isorhamnetin or quercetin on cytoplasmic lipid droplet accumulation and control untreated cells. Isorhamnetin at physiologically attainable concentrations was more effective than quercetin in inhibiting cytoplasmic lipid droplet accumulation. Neither isorhamnetin nor quercetin had an effect on the expression of macrophage chemoattractant protein -1 (MCP-1). CCAAT/enhancer binding protein α (C/EBP-α) was down-regulated by isorhamnetin. Compared to control, isorhamnetin or quercetin decreased PPAR-γ 1 and 2 expressions. The data indicate that isorhamnetin more than quercetin was effective at physiologically attainable concentrations in reducing lipid accumulation in 3T3-L1 pre-adipocytes.

Antioxidant capacity of Nitraria retusa leaf extracts against mitomycin C-induced genetic toxicity in male mice

BackgroundRecently, a great interest in the usage of new derived drugs extracted from plant has been increased to treat and/or prevent several diseases including cancer. Therefore, the present study was conducted to use Nitraria retusa leaf extract to increase the antioxidant activity and reduce the genotoxic activity of chemotherapeutic drugs mitomycin C (MMC) in male mice. Male Swiss albino mice (n = 80) were divided in several experimental groups and treated with single dose of MMC with supplementation of 50 and 100 mg/kg body wt Nitraria retusa leaf extract for several time intervals (3 days, 1 week, and 1 month).ResultsThis study found that MMC-treated mice observed significant increases in the frequency of chromosomal abnormalities in both cell types including bone marrow and spermatocyte cells, induce the mean values of DNA damage, and decrease the expression values of antioxidant enzyme-related genes (CAT, GPx, and GSTT1) compared with control mice. However, supplementation of MMC-treated mice with Nitraria retusa leaf extract suppressed the harmful impacts induced by MMC especially with the high dose and longer duration of the administration.ConclusionThe results suggested that the protective capacity of the Nitraria retusa leaf extract in protecting the hepatic cells could be attributed to the presence of isorhamnetin 3-o-robinobioside, palmitic acid, and β-sitosterols in its extract which are known for their anti-tumor and anti-mutagenic activities.

Antibacterial Activity of Polyphenolic Fraction of Kombucha Against Enteric Bacterial Pathogens.

The emergence of multi-drug-resistant enteric pathogens has prompted the scientist community to explore the therapeutic potentials of traditional foods and beverages. The present study was undertaken to investigate the efficacy of Kombucha, a fermented beverage of sugared black tea, against enterotoxigenic Escherichia coli, Vibrio cholerae, Shigella flexneri and Salmonella Typhimurium followed by the identification of the antibacterial components present in Kombucha. The antibacterial activity was evaluated by determining the inhibition zone diameter, minimal inhibitory concentration and minimal bactericidal concentration. Kombucha fermented for 14days showed maximum activity against the bacterial strains. Its ethyl acetate extract was found to be the most effective upon sequential solvent extraction of the 14-day Kombucha. This potent ethyl acetate extract was then subjected to thin layer chromatography for further purification of antibacterial ingredients which led to the isolation of an active polyphenolic fraction. Catechin and isorhamnetin were detected as the major antibacterial compounds present in this polyphenolic fraction of Kombucha by High Performance Liquid Chromatography. Catechin, one of the primary antibacterial polyphenols in tea was also found to be present in Kombucha. But isorhamnetin is not reported to be present in tea, which may thereby suggest the role of fermentation process of black tea for its production in Kombucha. To the best of our knowledge, this is the first report on the presence of isorhamnetin in Kombucha. The overall study suggests that Kombucha can be used as a potent antibacterial agent against entero-pathogenic bacterial infections, which mainly is attributed to its polyphenolic content.

Investigation on the interaction between isorhamnetin and bovine liver catalase by spectroscopic techniques under different pH conditions.

The binding of isorhamnetin to bovine liver catalase (BLC) was first investigated at 302, 310 and 318 K at pH 7.4 using spectroscopic methods including fluorescence spectra, circular dichroism (CD) and UV-vis absorption. Spectrophotometric observations are rationalized mainly in terms of a static quenching process. The binding constants and binding sites were evaluated by fluorescence quenching methods. Enzymatic activity of BLC in the absence and presence of isorhamnetin was measured using a UV/vis spectrophotometer. The result revealed that the binding of isorhamnetin to BLC led to a reduction in the activity of BLC. The positive entropy change and enthalpy change indicated that the interaction of isorhamnetin with BLC was mainly driven by hydrophobic forces. The distance r between the donor (BLC) and acceptor (isorhamnetin) was estimated to be 2.99 nm according to fluorescence resonance energy transfer. Fluorescence, synchronous fluorescence, and CD spectra showed no obvious change in the conformation of BLC upon the binding of isorhamnetin. In addition, the influence of pH on the binding of isorhamnetin to BLC was investigated and the binding ability of the drug to BLC deceased under other pH conditions (pH 9.0, 6.5, 5.0, 3.5, or 2.0) as compared with that at pH 7.4. Copyright © 2016 John Wiley & Sons, Ltd.

Antiadipogenic activity of isohamnetin 3-O-β-D-glucopyranoside from Salicornia herbacea

In the present study, effect of flavonoid glucopyranoside, isorhamnetin 3-О-β-D-glucopyranoside, from Salicornia herbacea on adipogenic differentiation were evaluated in 3T3-L1 adipocytes. Confluent 3T3-L1 preadipocytes in medium (0.5 mM methylisobutylxanthine, 0.25 µM dexamethasone, 5 µg/mL insulin, and 10% fetal bovine serum [FBS]) were differentiated into adipocytes for 6 days with/without isorhamnetin 3-О-β-D-glucopyranoside. The presence of isorhamnetin 3-О-β-D-glucopyranoside effectively suppressed adipogenic differentiation by downregulation of peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer-binding proteins (C/EBPα), sterol regulatory element-binding protein 1 (SREBP1), and the adipocyte-specific proteins. Moreover, the specific mechanism mediating the effects of isorhamnetin 3-О-β-D-glucopyranoside was confirmed by activation of AMP-activated protein kinase (AMPK). These findings suggest that isorhamnetin 3-О-β-D-glucopyranoside exerts antiadipogenic activity through AMPK activation. This study should find the nutraceutical value of S. herbacea-derived glucopyranoside, isorhamnetin 3-О-β-D-glucopyranoside, as potent candidate of antiobesity agent via alleviation of lipid accumulation.

Abstract 1978: Isorhamnetin modulates PPARδ activation pathway leading to the suppression of proliferation, invasion and induction of apoptosis in gastric cancer

Abstract Background: Gastric cancer, including cancer of the esophago-gastric junction, is the fourth most common malignant tumor and the second-most common cause of cancer-related death. Though treatment options such as chemotherapy, radiotherapy and surgery are available, only a modest survival rate has been observed, with the most common complications being chemoresistance and tumor recurrence. Majority of gastric adenocarcinomas have been related to chronic inflammation induced by Helicobacter pylori infection. Peroxisome proliferator-activated receptors are ligand-activated intracellular transcription factors that have been shown to be involved in tumor growth. However, its role in gastric cancer remains unclear. In this study, we report the anticancer effects of Isorhamnetin (IH), a 3′-O-methylated metabolite of quercetin on gastric cancer cells, and its potential effect on the PPAR-γ activation pathway. Method: Various gastric cancer cell lines were used in the study. To investigate the effect of IH on gastric cancer cells, we used techniques such as cell proliferation assays, wound healing assay, matrigel invasion assay, western blot analysis, cell cycle analysis, real time PCR analyses and live and dead assay. Whether IH could modulate activation of PPAR-γ was also investigated by molecular docking analysis. Results: We found that IH exerted strong anti-proliferative effect in gastric cancer cells and, when combined with 5-fluorouracil and cisplatin, increased cytotoxicity. IH was found to increase sub-G1 accumulation and annexin-V positive staining, indicating apoptotic induction. In addition, IH activated caspases 8, 9 and 3 in a time-dependent manner. Migratory and invasive properties of gastric cancer cells were also reduced in the presence of IH. Interestingly, we report for the first time that IH was able to increase PPAR-γ activity and down-regulate the expression of the genes for Bcl-2, Bcl-xL and survivin in gastric cancer cells. More importantly, the increase in PPAR-γ activity was prevented in the presence of PPAR-γ specific inhibitor and PPAR-γ dominant negative plasmid, suggesting that IH may act as a ligand of PPAR-γ. Also, we observed using molecular docking analysis that IH indeed formed interactions with 7 polar residues and 6 non-polar residues within the ligand-binding pocket of PPAR-γ that are reported to be critical for its activity. Conclusion: Taken together, our novel observations suggest that IH may have potential implication in gastric cancer prevention and treatment, and show for the first time that the anti-tumor effect of IH may also be mediated through modulation of the PPAR-γ activation pathway. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1978. doi:1538-7445.AM2012-1978

Leaf flavonoid chemistry and the relationships of theLactoridaceae

Leaves of the monotypic angiosperm familyLactoridaceae exhibit flavonoid constituents consisting of six 3-0-diglycosides of the flavonols kaempferol and isorhamnetin. The presence of flavonols is concordant with the placement ofLactoridaceae among the “archaic” or “primitive” flowering plants. Flavonoid chemistry is less informative on the relationships of the family within the primitive dicots. The presence of isorhamnetin suggests closer affinities with families in theLaurales, particularly theGomortegaceae andMonimiaceae. Phenetic and cladistic analyses of morphological features place theLactoridaceae near several families in theMagnoliales.