In Vitro Studies on the Binding, Antioxidant, and Cytotoxic Actions of Punicalagin

Abstract

The protective bioactivity of punicalagin, a high molecular weight polyphenol isolated from pomegranate fruit pith and carpellary membrane, against oxidative damages to lipids, amino acids constituting the proteins, and guanosine as a model for DNA has been investigated. The ABTS*-, guanosine, and tryptophan radical generated pulse radiolytically were repaired by punicalagin, k = (0.9-15) x 10(7) dm3 mol-1 s-1. The results are rationalized on the basis of the scavenging activity of punicalagin against various one-electron oxidizing radicals, namely, .OH, N3., and NO2. . The formation of the transient species in these reactions and the rate constants of the scavenging reactions have been probed using a time-resolved kinetic spectrophotometric technique. The antioxidant action of punicalagin is expressed not only through its scavenging reactions but also by its ability to form metal chelates. Binding of punicalagin with bovine serum albumin and metal ions such as iron and copper revealed different binding affinities, whereas its binding with DNA was very weak and nonspecific. In vitro cytotoxic studies against three cell lines, namely, Vero (normal African green monkey kidney cell line), Hep-2 (human larynx epithelial cancer cell line), and A-549 (human small cell lung carcinoma cell line) showed that this polyphenol is toxic only at higher concentration.

Punicalagin protects bovine endometrial epithelial cells against lipopolysaccharide-induced inflammatory injury

“…In this study, punicalagin did not have toxic effects on bEECs at concentrations of 0-30 µg/ml. These results are consistent with those of Kulkarni et al (2007) showing that punicalagin is toxic only at higher concentrations in cells of Vero (a normal African green monkey kidney cell line), Hep-2 (a human larynx epithelial cancer cell line), and A-549 (a human small cell lung carcinoma cell line). This indicates that the inhibition of LPS-induced inflammatory injury in bEECs was not a result of toxicity.…”

A Review Study on Punica granatum L

“…43 Free radicals can cause oxidative stress, which may induce damage to biomolecules, leading to many chronic diseases, such as cancer, 44 56,57 and other degenerative diseases. Antioxidant activity of pomegranate fruit has been attributed to the presence of some components like ascorbic acid and phenolic compounds, including punicalagin, punicalin, gallic acid, ellagic acid, and anthocyanins.…”

Determination of Punicalagin Isomers in Pomegranate Husk

“…The potent bioactivity of punicalagins can be explained by its ability to hydrolyze into ellagic acid (EA) in vivo and across the mitochondrial membrane in vitro. It was also found to protect against oxidative damages to lipids, amino acids and guanosine as [2].…”