Assessment of the Biological Activity and Phenolic Composition of Ethanol Extracts of Pomegranate (Punica granatum L.) Peels

Abstract

Pomegranate (Punica granatum L.) is a rich source of constituents with confirmed strong biological activities. However, pomegranate peel, which encompasses approximately 30–40% of its weight, is treated as a biological waste. The aim of this paper was to evaluate the potential of pomegranate peel extracts and to propose its functional properties that can be used for development of functional products. Eight ethanol extracts of pomegranate peels (PPEs) were characterized by use of direct infusion quadrupole-time of flight (Q-TOF), and afterwards tested on their antioxidant, antibacterial and antiproliferative activities. Mass spectrometry analysis revealed that the most prevalent compounds in pomegranate peels were punicalagin, granatin and their derivatives. Analysed extracts had high total phenolic contents that ranged from 5766.44 to 10599.43 mg GAE/100 g, and strong antioxidant activity (7551.31–7875.42 and 100.25–176.60 μmol TE/100 g for DPPH and FRAP assays, respectively). The results of biological activity assays showed that all PPEs possessed antibacterial activity, and that S. aureus was the most sensitive specie with minimum inhibitory concentration and minimum bactericidal concentrations ranging from 0.8 to 6.4 mg/mL. Additionally, the analysis of antiproliferative activity revealed high potency of PPEs, as the IC50 values ranged from 0.132 mg/mL to 0.396 mg/mL. Multivariate analysis pointed out the most discriminative metabolites for antioxidant or antiproliferative activity. Overall, the pomegranate peel confirmed to be a highly valuable source of bioactive compounds that could be used to improve the food functional characteristics.

Ameliorative Effect of Neem Leaf and Pomegranate Peel Extracts in Coccidial Infections in New Zealand and V-Line Rabbits: Performance, Intestinal Health, Oocyst Shedding, Carcass Traits, and Effect on Economic Measures

“…Studies in the literature used several different forms of extract, including ethanolic, methanolic, and water. Our results were in agreement with other published data, most of which showed the most beneficial health effects following treatment with ethanolic extracts [ 38 , 75 , 76 ]. In general, pomegranate peel extract has been confirmed as a highly valuable source of bioactive compounds that can be used to improve the functional characteristics of food when used in ethanolic form [ 76 ].…”

“…Our results were in agreement with other published data, most of which showed the most beneficial health effects following treatment with ethanolic extracts [ 38 , 75 , 76 ]. In general, pomegranate peel extract has been confirmed as a highly valuable source of bioactive compounds that can be used to improve the functional characteristics of food when used in ethanolic form [ 76 ]. The mix of flavonoids, polyphenols, and other active ingredients found in pomegranate peel have been published previously, confirming that the antioxidant activity in the pomegranate can be attributed mainly to its polyphenol, quercetin, and rutin contents [ 77 ].…”

Antioxidant Effect of Moroccan Pomegranate (Punica granatum L. Sefri Variety) Extracts Rich in Punicalagin against the Oxidative Stress Process

“…A similar trend was observed with the results obtained by Li et al [ 57 ] and Sabraoui et al [ 3 ], who found that the reducing power of a peel extract was higher than that of an aril extract. Zeljka et al also reported that peel extracts exhibit strong antioxidant activity (100.25–176.60 μmol Trolox Eq/100 g) in reducing the Fe(III)-TPTZ complex [ 58 ]. The reducing power of pomegranate fruit parts is probably due to the action of the hydroxyl groups of phenolic compounds, which may act as electron donors.…”

The bioactivity and applications of pomegranate peel extract: A review

“…Vildan et al (2020) studied the anti‐inflammatory activity of punicalagin to evaluate the in vitro oral wound healing effect of angarin combined with zinc. Peršurić et al (2020) revealed the anti‐bacterial activity of punicalin through PLS‐DA experimental analysis. Chukwuma et al (2020) confirmed the anti‐diabetes and anti‐oxidation properties of gallic acid from propanol extract of PP. The comprehensive utilization value of pomegranate can be improved by extracting effective substances from PP.…”

“…studied the anti-tumor activity of punicalagin and discussed its anti-proliferation mechanism on A549 cell line and MRC-5 cell line Vildan et al (2020). studied the anti-inflammatory activity of punicalagin to evaluate the in vitro oral wound healing effect of angarin combined with zinc Peršurić et al (2020). revealed the anti-bacterial activity of punicalin through PLS-DA experimental analysis Chukwuma et al (2020).…”