Resvega Alleviates Hydroquinone-Induced Oxidative Stress in ARPE-19 Cells

Abstract

Retinal pigment epithelial (RPE) cells maintain homeostasis at the retina and they are under continuous oxidative stress. Cigarette smoke is a prominent environmental risk factor for age-related macular degeneration (AMD), which further increases the oxidant load in retinal tissues. In this study, we measured oxidative stress and inflammatory markers upon cigarette smoke-derived hydroquinone exposure on human ARPE-19 cells. In addition, we studied the effects of commercial Resvega product on hydroquinone-induced oxidative stress. Previously, it was observed that Resvega induces autophagy during impaired protein clearance in ARPE-19 cells, for which it has the potential to alleviate pro-inflammatory pathways. Cell viability was determined while using the lactate dehydrogenase (LDH) and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, and the cytokine levels were measured using the enzyme-linked immunosorbent assay (ELISA). Reactive oxygen species (ROS) production were measured using the 2′,7′-dichlorofluorescin diacetate (H2DCFDA) probe. Hydroquinone compromised the cell viability and increased ROS production in ARPE-19 cells. Resvega significantly improved cell viability upon hydroquinone exposure and reduced the release of interleukin (IL)-8 and monocytic chemoattractant protein (MCP)-1 from RPE cells. Resvega, N-acetyl-cysteine (NAC) and aminopyrrolidine-2,4-dicarboxylic acid (APDC) alleviated hydroquinone-induced ROS production in RPE cells. Collectively, our results indicate that hydroquinone induces cytotoxicity and increases oxidative stress through NADPH oxidase activity in RPE cells, and resveratrol-containing Resvega products prevent those adverse effects.

Effects of Resvega on Inflammasome Activation in Conjunction with Dysfunctional Intracellular Clearance in Retinal Pigment Epithelial (RPE) Cells

“…It is in line with our previous study where we saw that 25 μM Resvega alone did not compromise cell viability [ 30 ]. We have previously shown that Resvega can improve cell viability determined by both MTT and LDH assays during hydroquinone-induced oxidative stress or MG-132 exposure on ARPE-19 cells [ 29 , 30 ]. In the present study, Resvega preserved the integrity of cell membranes with disrupted protein clearance but had no effect on the cellular metabolic activity measured using the MTT assay.…”

“…The level of IL-6 was reduced by MG-132, a well-known NF-κB inhibitor, with bafilomycin [ 40 ]. We have previously shown that hydroquinone-mediated NF-κB inhibition resulted in diminished IL-6 levels, where Resvega returned to the control level independently of NF-κB activation [ 29 ]. In the present study, 10 μM Resvega had no additional effect on the IL-6 release upon MG-132 and BafA treatments.…”

“…After the treatments, 25 μL MTT salt (10 mg/mL) was added to the cells for 3 h at +37 °C, 5% CO 2 . The assay was performed as described previously [ 29 ]. Absorbance values were determined using the spectrophotometer at a wavelength of 560 nm.…”

“…In comparison to the Age-Related Eye Disease Study (AREDS) formulations, Resvega has resveratrol as an additional component [ 27 , 28 ]. In previous studies on ARPE-19 cells, Resvega has reduced hydroquinone-mediated ROS production and promoted autophagy during impaired protein clearance [ 29 , 30 ]. Resveratrol alone has been shown to induce autophagy and evoke anti-inflammatory responses in RPE cells as well inhibit NLRP3 expression, caspase-1 activation, and IL-1β secretion in a mouse model of acute lung injury [ 31 , 32 ].…”

Autophagy in Age-Related Macular Degeneration: A Regulatory Mechanism of Oxidative Stress

“…Additionally, a number of lifestyle factors, including smoking [ 21 ], improper dietary intake [ 22 , 23 ], obesity [ 24 ], and lack of exercise [ 25 ], are associated with a higher prevalence of AMD. Cigarette smoke can cause accumulation of cadmium (Cd) [ 26 ] and further increase the oxidant load in retinal tissues [ 27 ]. Dietary zinc deficiency can sensitize RPE cells to oxidative damage [ 28 ].…”