Chemical Composition and Biological Activity of Allium cepa L. and Allium × cornutum (Clementi ex Visiani 1842) Methanolic Extracts

Abstract

Here, we report a comparative study of the phytochemical profile and the biological activity of two onion extracts, namely Allium cepa L. and Allium × cornutum (Clementi ex Visiani 1842), members of the family Amaryllidaceae. The identification of flavonoids and anthocyanins, and their individual quantities, was determined by high-performance liquid chromatography (HPLC). The potency of both extracts to scavenge free radicals was determined by the DPPH (2,2′-diphenyl-1-picrylhydrazyl) radical-scavenging activity and oxygen radical absorbance capacity (ORAC) methods. The DNA protective role was further tested by the single-cell gel electrophoresis (COMET) assay and by Fenton’s reagent causing double-strand breaks on the closed circular high copy pUC19 plasmid isolated from Escherichia coli. In the presence of both extracts, a significant decrease in DNA damage was observed, which indicates a protective role of Allium cepa and Allium × cornutum on DNA strand breaks. Additionally, cytotoxicity was tested on glioblastoma and breast cancer cell lines. The results showed that both extracts had antiproliferative effects, but the most prominent decrease in cellular growth was observed in glioblastoma cells.

Allium vegetables for possible future of cancer treatment

“…Besides, the methanolic extract of A . cornutum the same as the onion methanolic extract could hinder the genotoxic materials, inhibit the proliferation of cancer cells, and show antioxidant properties (Fredotović et al, ; Gohil & Kaul, ).…”

“…Pentylalliin and methyl alliin, glycolipids ↑Immune system function, antiproliferative effect on HaCaT cells, inhibition of DNA polymerase (Kuriyama et al, 2005), (Mollica, Zengin, Locatelli, Picot-Allain, & Mahomoodally, 2018), (Kucekova et al, 2011) (Belakhdar, Benjouad, & Abdennebi, 2015;Win, 2005), (Isbilen, Rizaner, & Volkan, 2018) Allium cornutum Quercetin 3,40-diglucoside, quercetin 40monoglucoside, anthocyanins, and delphinidin glucoside Anticancer, chemopreventative, antiproliferative, apoptosis, cell cycle arrest, antioxidant, genotoxic materials inactivation (Fredotović et al, 2017;Gohil & Kaul, 2016) include carotenoids, polyphenols, anthocyanins, gallic and ferulic acids, quercetin, tricosan, alkaloids, saponins, and tannins (Abbas et al, 2017;Awan, Butt, Haq, Ashfaq, & Suleria, 2017). So far, various mechanisms including inhibition of cell cycle progression and genotoxicity, histone modification, inhibition of angiogenesis and metastasis, and induction of apoptosis have been attributed to the anticancer activities of them (Druesne et al, 2004;Herman-Antosiewicz & Singh, 2004;Nakagawa et al, 2001;Singh et al, 2008;Türkoğlu, 2012).…”

“…Besides, the A. kurrat methanolic extract showed antitumor and (Isbilen et al, 2018). As octadecanoic acid exhibited proven antitumor activities, they proposed that the higher antiproliferative activity of bulb extract might be related to greater amounts of this compound (Belakhdar et al, 2015;Win, 2005 (Fredotović et al, 2017;Gohil & Kaul, 2016).…”

Comparison of Organosulfur and Amino Acid Composition between Triploid Onion Allium cornutum Clementi ex Visiani, 1842, and Common Onion Allium cepa L., and Evidences for Antiproliferative Activity of Their Extracts

“…Flavonoids are responsible for the color of onion skin. They possess a strong antioxidant activity which makes them one of the best antioxidants and scavengers of free radicals [12,13]. After the consumption of onions, flavonoids are absorbed primarily from the stomach or/and small intestine [14].…”

“…In addition, amino acids contribute to the sensory response and to the characteristic "umami" taste [18]. Not only might free amino acids be used in the protein formation, but they also happen to be an important nitrogen reservoir, which additionally contributes to the nutritional value of the Allium species [12]. Arginine (Arg) is an amino acid which appears to be present in huge amounts in onions, which correlates with the hypothesis that onions use Arg as a nitrogen reservoir [19].…”