Oxidative Stress Type Influences the Properties of Antioxidants Containing Polyphenols in RINm5F Beta Cells

Abstract

The in vitro methods currently used to screen bioactive compounds focus on the use of a single model of oxidative stress. However, this simplistic view may lead to conflicting results. The aim of this study was to evaluate the antioxidant properties of two natural extracts (a mix of red wine polyphenols (RWPs) and epigallocatechin gallate (EGCG)) with three models of oxidative stress induced with hydrogen peroxide (H2O2), a mixture of hypoxanthine and xanthine oxidase (HX/XO), or streptozotocin (STZ) in RINm5F beta cells. We employed multiple approaches to validate their potential as therapeutic treatment options, including cell viability, reactive oxygen species production, and antioxidant enzymes expression. All three oxidative stresses induced a decrease in cell viability and an increase in apoptosis, whereas the level of ROS production was variable depending on the type of stress. The highest level of ROS was found for the HX/XO-induced stress, an increase that was reflected by higher expression antioxidant enzymes. Further, both antioxidant compounds presented beneficial effects during oxidative stress, but EGCG appeared to be a more efficient antioxidant. These data indicate that the efficiency of natural antioxidants is dependent on both the nature of the compound and the type of oxidative stress generated.

Aspalathin Protects Insulin‐Producing β Cells against Glucotoxicity and Oxidative Stress‐Induced Cell Death

“…STZ induces the formation of all these kinds of ROS and therefore is an appropriate inducer of multiple levels of oxidative stress for diabetes studies. [ 24,25 ]…”

Beneficial Effect of Jojoba Seed Extracts on Hyperglycemia-Induced Oxidative Stress in RINm5f Beta Cells

“…For example, monomers such as quercetin [ 44 ], procyanidins [ 45 , 46 ], gallic acid [ 47 ], and other flavonoids such as genistein [ 48 ] modulate cell proliferation in many cell types, including osteoblasts [ 44 ], fibroblasts [ 48 ], and several carcinoma cell lines [ 46 ]. Auberval et al [ 49 ] tested epigallocatechin gallate (EGCG) in RINm5f beta cells and showed that EGCG induced an increase in cell viability at concentrations of 500 μg/mL and 1000 μg/mL. In contrast, many studies established that polyphenols were capable of inhibiting cell proliferation by arresting cell cycle and apoptosis in several solid tumor cell lines [ 50 , 51 , 52 , 53 , 54 ].…”

Treatment of NASH with Antioxidant Therapy: Beneficial Effect of Red Cabbage on Type 2 Diabetic Rats

“…The use of natural bioactive compounds may present a novel promising approach. Biological activities and beneficial properties of dietary polyphenols have been reported such as antioxidant, anti-inflammatory, antimicrobial, and immunomodulatory properties, in addition to protect β -cells from OS-induced loss of viability in vitro [ 11 ] and in vivo [ 12 ] and endothelial cells from OS-associated aging [ 13 ]. Moreover, preclinical and phase II clinical trials recently investigated natural therapy efficacy on hepatic signalling pathways [ 14 ], and several reports highlighted an inverse correlation between cardiometabolic mortality/morbidity risk and the consumption of polyphenol-rich products in animal diabetic models and human [ 6 ], especially fruits and vegetable consumption and reduction of diabetes [ 15 , 16 ].…”