Muscadine grape component-extracts: antioxidant effects and inhibition of pancreatic cancer cell growth

Muscadine grapes ( Vitis rotundifolia ) are rich in polyphenolic compounds with reported antioxidant and anticancer activities, yet the relative bioactivity of their anatomical components on cancer cells remains unclear and largely unexplored. This study evaluated the total polyphenol content, antioxidant capacity, and antiproliferative effects of skin, pulp, and seed extracts from red (Noble) and white (Carlos) muscadine cultivars against MIA PaCa-2 pancreatic cancer cells. Extracts were prepared from freeze-dried tissues and assessed using Folin–Ciocalteu, DPPH radical-scavenging assays, and acridine orange/ethidium bromide (AO/EB) cell viability staining. Seed extracts, particularly from the white cultivar, contained the highest polyphenol concentrations and exhibited the strongest antioxidant activity. Correspondingly, seed extracts produced the greatest reduction in MIA PaCa-2 cell viability, with significant cytotoxicity observed even at low concentrations. Mass spectrometry confirmed higher and more stable levels of ellagic acid in seed extracts than in skin and pulp. These findings demonstrate that muscadine grape seeds are a concentrated source of bioactive polyphenols with potent antioxidant and antiproliferative effects, supporting their potential application as functional food ingredients targeting oxidative stress and cancer-related pathways.