Polyphenolic Extracts From Green Vegetables as Promoters of Fibroblast Viability and Reducers of Oxidative Stress

Over the past decades, extensive research has demonstrated and confirmed the antioxidant potency of polyphenols, which due to these properties, are now widely recognized for their ability to enhance cell viability. This study investigates the antioxidant capacity of seven green leafy vegetables on in vitro mouse (L929) and human (BJ) fibroblast cell lines, aiming to determine if polyphenols could aid the regeneration of connective tissue, which would be strongly beneficial in wound healing and tissue repair, a process where fibroblast thriving is essential. The antioxidant capacity of extracts was investigated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, UV-Vis spectroscopy, and amperometry, with quercetin serving as a standard. The EC₅₀ values for the extracts were equivalent to approximately 5 μM quercetin, derived from a concentration range of 20 to 100 mg of fresh leaves per mL. In vitro investigations revealed that all extracts, except lovage, promoted high viability (over 80%) in both cell cultures, as shown by MTS assay results and fluorescence microscopy. Additionally, Tumor Necrosis Factor (TNF)-α and Lipopolysaccharide (LPS) were employed as reactive oxygen species (ROS) antagonists, and the Dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay was used to demonstrate the extract's scavenging activity on fibroblasts in vitro. For some extracts, a reduction in oxidative stress compared to the cells basal metabolic conditions was observed.