Grape Canes from Typical Cultivars of Campania (Southern Italy) as a Source of High-Value Bioactive Compounds: Phenolic Profile, Antioxidant and Antimicrobial Activities

Abstract

The purpose of the current study was to determine the phenolic composition, antioxidant, and antimicrobial activities in grape cane extracts from typical cultivars of Southern Italy. Aqueous extracts at different pHs (1–13) were prepared from “Aglianico”, “Fiano”, and “Greco” grape canes. The results demonstrated that an alkaline pH (13.00) produced the best polyphenol-rich extracts, as the total phenolic content was more than double when compared to the respective extracts prepared at pH 1.00. “Greco” grape canes gave the highest quantity of phenolic compounds at each pH, ranging from 42.7 ± 0.4 to 104.3 ± 3.0 mg Gallic Acid Equivalents (GAE)/g Dry Extract (DE) from pH 1.00 to 13.00. The Radical Scavenging Activity (RSA) and the Ferric Reducing Antioxidant Power (FRAP) were measured. The highest antioxidant activity was showed by “Greco” extract at pH 7.00. Seventy-five compounds were identified in the extracts by HPLC-MS with six of them described for the first time in grape canes. Procyanidins were highly abundant in extracts at pH 7.00, whereas stilbenoids were the most represented compounds at pH 13.00. Very strong antiviral activity against herpes simplex viruses was recorded for the extracts at pH 7.00 and 13.00 that were active in the early stages of infection by acting directly against the viral particles. The overall results suggest that grape canes, currently underutilized, can be usefully valorised by providing active extracts to use as antioxidant and antiviral agents.

Antiviral Activity of Vitis vinifera Leaf Extract against SARS-CoV-2 and HSV-1

“…All experiments were performed in triplicate. Greco extract was used as a positive control for HSV-1 and SARS-CoV-2 antiviral assays [ 11 ].…”

“…As HSV-1, no relevant inhibition was detected when the concentration of the extract was reduced to 5 µg/mL. The leaf extract definitely showed a stronger antiviral potential than Greco extract, which was used as a positive control (CTRL +) against HSV-1 and SARS-CoV-2 [11,[64][65][66]. The leaf extract definitely showed a stronger antiviral potential than Greco extract, which was used as a positive control (CTRL+) against HSV-1 and SARS-CoV-2 [11,[64][65][66].…”

“…Very recently, we characterized the phenolic constituents, antioxidant, antibacterial, and, mainly, the antiherpetic activity of grape cane extracts derived from typical cultivars of Southern Italy [11], i.e., Greco, Aglianico, and Fiano. We prepared various extracts in a range of different pHs (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13), demonstrating that the extraction at pH 13.00 was the optimal condition, since the phenolic yield was the highest. We described the presence of 75 compounds with different abundance profiles at various pHs and, interestingly, six of them were identified for the first time in grape canes.…”

“…Grapevine is a plant rich in bioactive compounds [ 5 , 6 ], known for its therapeutic effects. The grape extract was studied for a long time for its hepatoprotective [ 7 ], hypoglycemic [ 8 ], cardio-protective [ 9 ], antioxidant [ 10 , 11 ], antibacterial [ 11 , 12 , 13 ], and antiviral activity [ 11 , 14 ] which are due to the high levels of polyphenolic compounds found in grapes skin, seeds, and stem. The anti-cancer effect, that has long been studied over the years, is attributable to the consistent antioxidant activity of these molecules [ 15 , 16 ].…”

“…The fractioned content derived from chloroform extract showed higher inhibition capability, both against Herpes simplex virus type 1 (HSV-1) and Parainfluenza virus (PIV). Very recently, we characterized the phenolic constituents, antioxidant, antibacterial, and, mainly, the antiherpetic activity of grape cane extracts derived from typical cultivars of Southern Italy [ 11 ], i.e., Greco, Aglianico, and Fiano. We prepared various extracts in a range of different pHs (1–13), demonstrating that the extraction at pH 13.00 was the optimal condition, since the phenolic yield was the highest.…”