Study of Anticancer Activities of Muscadine Grape Phenolics in Vitro

Abstract

Muscadine grapes have unique aroma and flavor characteristics. Although a few studies reported high polyphenols content of muscadine grapes, little research has been conducted to evaluate the phenolic compounds bioactivities in any muscadine grape cultivar. The objective of this study was to evaluate the effect of phenolic compounds in muscadine grapes on cancer cell viability and apoptosis. Four cultivars of muscadine (Carlos, Ison, Noble, and Supreme) were assessed in this study. Phenolic compounds were extracted from muscadine skins and further separated into phenolic acids, tannins, flavonols, and anthocyanins using HLB cartridge and LH20 column. Some individual phenolic acids and flavonoids were identified by HPLC. Anthocyanin fractions were more than 90% pure. The effect of different fractions on the viability and apoptosis of two colon cancer cell lines (HT-29 and Caco-2) was evaluated. A 50% inhibition of cancer cell population growth for the two cell lines was observed at concentrations of 1-7 mg/mL for crude extracts. The phenolic acid fractions showed a 50% inhibition at the level of 0.5-3 mg/mL. The greatest inhibitory activity was found in the anthocyanin fraction, with a 50% inhibition at concentrations of approximately 200 microg/mL in HT-29 and 100-300 microg/mL in Caco-2. Anthocyanin fractions also resulted in 2-4 times increase in DNA fragmentation, indicating the induction of apoptosis. These findings suggest that polyphenols from muscadine grapes may have anticancer properties.

Pilot Study of Oral Anthocyanins for Colorectal Cancer Chemoprevention

“…Although the biological importance of such a slight decrease is debatable, its observation supports the notion that, in principle, bilberry anthocyanins can exert a pharmacologic effect in humans. Antiproliferative effects of mirtocyan anthocyanins are consistent with reports of the ability of anthocyanins to arrest growth and induce apoptosis in vitro in cells derived from a variety of malignancies (9), notably those of the gastrointestinal tract (26,27). The increase in apoptosis observed here in postintervention compared with preintervention tumor samples are difficult to interpret as it may have been the consequence of the surgical procedure rather than agent intervention.…”

<i>p</i>-Coumaroyl Anthocyanin Mixture Isolated from Tuber Epidermis of <i>Solanum tuberosum</i> Attenuates Reactive Oxygen Species and Pro-inflammatory Mediators by Suppressing NF-κB and STAT1/3 Signaling in LPS-Induced RAW264.7 Macrophages

“…[28][29][30] Colored rice extract suppresses LPS-induced inflammation by inhibition of the mitogen-activated protein kinase (MAPK) signaling pathway, which leads to decreased NF-κB and AP-1 translocation.…”

The comparative study among different fractions of muscadine grape ‘Noble’ pomace extracts regarding anti-oxidative activities, cell cycle arrest and apoptosis in breast cancer

“…Fractions from ‘Noble’ pomace extracts were prepared based on a method described in a previous study [12]. All fractions were dissolved in DMSO.…”

“…In previous reports, researchers found variable abilities to inhibit colon cancer among fractions from muscadine grape [11,12], although the analysis was limited only to the phenolic fractions or EA-rich fractions derived from fresh grape skin and/or pulp excluding extracts from seeds. On the other aspects, the anti-oxidative activity, the cell cycle arrest, and the induction of apoptosis in cancer cells were used to evaluate and compare the anti-cancer function exerted by different phenolic fractions [11].…”