Novel insights on the multi-functional properties of flavonol glucosides from red onion (Allium cepa L) solid waste – In vitro and in silico approach

UHPLC-MS Chemical Fingerprinting and Antioxidant, Antiproliferative, and Enzyme Inhibition Potential of Gaultheria pumila Berries

“…In docking studies, chlorogenic acid was demonstrated to inhibit cholinesterase enzymes [ 64 ]. Isoquercitrin exhibited potent alpha-glucosidase, tyrosinase, and xanthine oxidase enzyme-inhibitory activities [ 65 ]. Delphinidin-3- O -glucoside, cyanindin-3- O -glucoside, peonidin-3- O -glucoside, and malvidin-3- O -glucoside were the principal anthocyanin detected in red wines from Serbia vineyards, which were related to AChE inhibitory activity [ 66 ].…”

Onion Peel: Turning a Food Waste into a Resource

“…Nevertheless, our results agree with data performed on rat intestinal α-glucosidase thus supporting that also in yeast the tested compounds have a constant inhibitory effect. Moreover, α-glucosidase inhibition mechanism of flavonoids and in particular of quercetin, as common plant flavonoid, and main compound in our extracts, has been often investigated [52,[55][56][57]. All these studies, reported quercetin acting with as mixed close to non-competitive inhibition type, thus suggesting that this flavonoid can bind both free enzyme and enzyme-substrate complex, whereas 3-OH glycosylated derivatives can vary their inhibitory mechanism toward a competitive inhibition [55][56][57][58].…”

“…Moreover, α-glucosidase inhibition mechanism of flavonoids and in particular of quercetin, as common plant flavonoid, and main compound in our extracts, has been often investigated [52,[55][56][57]. All these studies, reported quercetin acting with as mixed close to non-competitive inhibition type, thus suggesting that this flavonoid can bind both free enzyme and enzyme-substrate complex, whereas 3-OH glycosylated derivatives can vary their inhibitory mechanism toward a competitive inhibition [55][56][57][58]. Overall, our results confirmed that these extracts, act as potent α-glucosidase inhibitors, and suggest that both "Ramata di Montoro" and "Rossa di Tropea" onion skins extracts have the potential to efficaciously contribute as dietary supplements for both the postprandial glycemia control and diabetes-related cellular oxidative stress; nevertheless, further studies will be performed to elucidate the structure-activity relationships of flavonoids inhibitory power in our onion skin extracts.…”

Ameliorative effects of Allium cepa Linn. scaly leaves extract on reproductive dysfunctions in streptozotocin-induced diabetic Wistar rats

“…Energy in sperm cells is mainly used to maintain the motility to complete capacitation and subsequent acrosome reaction (Yanagimachi, 1994;Flesch and Gadella, 2000;Harrison and Gadella, 2005). Quercetin, the major derivative in Allium cepa is a strong antioxidant (Dias et al, 2005;Machavarapu et al, 2013;Nile et al, 2020), which help to ameliorate defects in male fertility arising from diabetes mellitus (Smith et al, 2003;Khaki et al, 2010;Jiet al, 2011). This potent antioxidant action of ACSLE may be the mechanism of ameliorating diabetic complications seen in the reproductive system.…”

“…Flavonoids subclasses can be further differentiated on the basis of the number and nature of substituent groups attached to the rings (P´erez-Gregorio et al, 2010). Flavonols are the most abundant in onions, present as their glycosides, that is, quercetin and kaempferol (Prakash et al, 2007;Santas et al, 2010;Nile et al, 2020) in higher concentration (280-400 mg/kg) than other vegetables (i.e., 100 mg/kg in broccoli, 50 mg/kg in apple) (de Ancos et al, 2015). Anthocyanins, belonging to anthocyanidins, are mainly present in red onions (250 mg/kg), besides having a composition rich in flavonols as yellow onions (de Ancos et al, 2015).…”