Antioxidant, Antimalarial and Antimicrobial Activities of Tannin-Rich Fractions, Ellagitannins and Phenolic Acids from Punica granatum L.

Abstract

The Punica granatum L. (pomegranate) by-product POMx was partitioned between water, EtOAc and n-BuOH, and the EtOAc and n-BuOH extracts were purified by XAD-16 and Sephadex LH-20 column chromatography to afford ellagic acid (1), gallagic acid (2), punicalins (3), and punicalagins (4). Compounds 1 - 4 and the mixture of tannin fractions (XAD-16 eluates) were evaluated for antioxidant, antiplasmodial, and antimicrobial activities in cell-based assays. The mixture of tannins (TPT), XAD-EtOAc, XAD-H2O, XAD-PJ and XAD-BuOH, exhibited IC50 values against reactive oxygen species (ROS) generation at 0.8 - 19 microg/mL. Compounds 1 - 4 showed IC50 values of 1.1, 3.2, 2.3 and 1.4 microM, respectively, against ROS generation and no toxicity up to 31.25 microg/mL against HL-60 cells. Gallagic acid (2) and punicalagins (4) exhibited antiplasmodial activity against Plasmodium falciparum D6 and W2 clones with IC50 values of 10.9, 10.6, 7.5 and 8.8 microM, respectively. Fractions XAD-EtOAc, XAD-BuOH, XAD-H2O and XAD-PJ compounds 1 - 4 revealed antimicrobial activity when assayed against Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Cryptococcus neoformans, methicillin-resistant Staphylococcus aureus (MRSA), Aspergillus fumigatus and Mycobacterium intracellulare. Compounds 2 and 4 showed activity against P. aeruginosa, C. neoformans, and MRSA. This is the first report on the antioxidant, antiplasmodial and antimicrobial activities of POMx isolates, including structure-activity relationships (SAR) of the free radical inhibition activity of compounds 1 - 4. Our results suggest a beneficial effect from the daily intake of POMx and pomegranate juice (PJ) as dietary supplements to augment the human immune system's antioxidant, antimalarial and antimicrobial capacities.

In vitro antimalarial activity and cytotoxicity of some selected cuban medicinal plants

“…In Cuba, as in other Latin American countries, P. granatum is used as antihelminthic and against intestinal disorders 6,27 . For this specie, amoebicidal 6 , antibacterial 17 , antifungal 21 and antileishmanial 12 activities have been reported.…”

Assessment of mutagenic and antimutagenic effects of Punica granatum in mice

“…In this regard, West et al (2007) showed that polyphenols present in this plant protect neonatal mouse brain against hypoxic-ischemic injury. Other examples of beneficial antioxidant activity effects of P. granatum include inhibition of UVB-mediated oxidative stress in immortalized HaCaT keratinocyte cells (Zaid et al, 2007), augmentation of the human immune system's antioxidant and thus antimalarial and antimicrobial capacities in vitro (Reddy et al, 2007), decrease in the expression of the vascular inflammation markers thrombospondin and cytokine TGFbeta1, along with an increase in plasma nitrate and nitrite levels and endothelial NO synthase expression in obese Zucker rats (De Nigris et al, 2007). Moreover, Kaur et al (2006) demonstrated FIGURE 2 -Effects of prophylactic oral treatment with Punica granatum ethanolic leaf extract -PGL and the ethanolic fruit extract -PGF (12.5; 25; 50 or 75mg/kg/day) for 10 days on the frequency of micronucleated polychromatic erythrocytes (MNPCE) in mice (n = 5) exposed to cyclophosphamide (CP).…”

“…Antitumour (Afaq et al, 2005;Lansky and Newman, 2007), antibacterial (Prashanth et al, 2001;Braga et al, 2005;Menezes et al, 2006;Aqil, Ahmad, 2007), antidiarrhoeal (Das et al, 1999;Mathabe et al, 2006), antifungal (Dutta et al, 1998;Vasconcelos et al, 2003;Vasconcelos et al, 2006), antiulcer (Gharzouli et al, 1999), and antioxidant pharmacological properties have been reported for various extracts/constituents of different parts of this plant species. Recently, the antioxidant activity of P. granatum associated with its phytochemicals, such as, polyphenols, flavonoids, and anthocyanidins has gained importance (Faria et al, 2007;Guo et al, 2007;Kulkarni et al, 2007;Mirdehghan et al, 2007;Reddy et al, 2007;Rout, Banerjee, 2007;Sestili et al, 2007;Zaid et al, 2007). In this regard, Negi et al (2003) demonstrated that the in vitro antioxidant ability of the pomegranate fruit, rich in polyphenols and anthocyanidins, was higher than that found in green tea, also considered a powerful antioxidant.…”

Assessing the efficacies of phenolic compounds in pomegranate juice using thin-layer chromatography

“…In Judaism, it is believed that each pomegranate has 613 seeds representing the 613 commandments of the Torah [1]. Current research on pomegranate has attempted to identify the basis of its healing properties, with a considerable number of studies conducted to uncover the antioxidant [3], antimicrobial [4], and anti-malarial [5] activities.…”