A Comparative Study on the Inhibitory Effects of Different Parts and Chemical Constituents of Pomegranate on α‐Amylase and α‐Glucosidase

Abstract

Pomegranate has been documented for the management of diabetes in Unani and Chinese medicine. This study compared the effects of the extracts of different pomegranate parts, including juice, peels, seeds and flowers, on carbohydrate digestive enzymes (α-amylase and α-glucosidase) in vitro. The methanolic flower extract inhibited α-amylase and α-glucosidase, while the methanolic peel extract inhibited α-glucosidase selectively. The most active flower extract was subjected to water-ethyl acetate partition. The ethyl acetate fraction was more potent than the water fraction in inhibiting both enzymes. Gallic acid and ellagic acid also showed selective inhibition against α-glucosidase, and their presence in the ethyl acetate fraction was confirmed by HPLC-DAD and HPLC-HESI-MS. Our findings suggest that the inhibition of carbohydrate digestive enzymes and their phenolic content may contribute to the anti-hyperglycaemic effects of pomegranate flower and peel, and support their claims in diabetes.

Functional Properties of Punica granatum L. Juice Clarified by Hollow Fiber Membranes

“…Recent studies demonstrated that the flower, peel, and seeds of pomegranate exhibit hypoglycaemic activities in several in vitro and in vivo models [45][46][47]. Phenolic compounds also affect digestive enzymes involved in the hydrolysis of dietary carbohydrates.…”

“…Kam et al [45] investigated the inhibitory activity of pomegranate flower, peel, seed and dried juice on α-amylase and α-glucosidase. The methanol flower extract inhibited both enzymes, while the methanol peel extract selectively inhibited the α-glucosidase.…”

Soluble polysaccharides reduce binding and inhibitory activity of tea polyphenols against porcine pancreatic α-amylase

“…In recent years, many phytochemicals have been studied for their inhibitory activity against a-amylase, like green coffee extracts (Narita & Inouye, 2011), tea extracts (Fei et al, 2014;Sun et al, 2016), pomegranate extracts (Kam et al, 2013), etc., and the main components that demonstrated the inhibitory activity were shown to be phenolic compounds. Aqueous extracts from fruits or plants are generally a mixture of polyphenols and soluble polysaccharides, in part due to binding interactions between the two components (Chamorro, Viveros, Alvarez, Vega, & Brenes, 2012).…”

Protective Effect of Pomegranate Peel Extract against DiabeticInduced Renal Histo-pathological Changes in Albino Rats

“…On the other hand [16] reported that the inhibition of carbohydrate digestive enzymes and their phenolic content may contribute to the anti-hyperglycemic effects of pomegranate flower and peel, and support their claims in diabetes. Studies carried by [17] indicated that the methanolic extract of pomegranate peel has beneficial influences and could be able to inhibit Al-induced oxidative stress and histo-pathological alternations in liver and kidney of female rats, and these effects may be related to anti-apoptotic and antioxidant activities.…”