The Phytoalexin Resveratrol Ameliorates Ochratoxin A Toxicity in Human Embryonic Kidney (HEK293) Cells

Abstract

Ochratoxin A (OTA) is a nephrotoxic mycotoxin produced by Aspergillus and Penicillium fungi. It contaminates human and animal food products, and chronic exposure is associated with renal fibrosis in humans (Balkan endemic nephropathy). Resveratrol, a phytoalexin, possesses anti-cancer and antioxidant properties. We investigated the mechanism of cellular oxidative stress induced by OTA, and the effect of resveratrol in human embryonic kidney (HEK293) cells over 24 and 48 h. Cells were exposed to OTA [IC50 ¼ 1.5 mM (24 h) and 9.4 mM (48 h) determined using MTT assay] and 25 mM resveratrol. Glutathione was quantified by luminometry and gene expression of Nrf2 and OGG1 was determined by qPCR. Protein expression of Nrf2, LonP1, SIRT3, and pSIRT1 was assessed by Western blot, DNA damage (comet assay), and intracellular reactive oxygen species (flow cytometry). At 24 h, resveratrol increased mRNA expression of the DNA repair enzyme, OGG1 (P < 0.05), whereas OTA and OTAþresveratrol significantly decreased OGG1 expression (P < 0.05). OGG1 expression increased during 48-h exposure to resveratrol and OTAþresveratrol (P < 0.05). Comet tail lengths doubled in 48-h OTA-treated cells, whereas at both time periods, OTAþresveratrol yielded shorter comet tails (P < 0.0001). During 24-and 48-h exposure, OTA, resveratrol, and OTAþresveratrol significantly decreased mRNA expression of Nrf2 (P < 0.05). Luminometry analysis of GSH revealed an increase by OTAþresveratrol for 24 and 48 h (P < 0.05 and P < 0.001, respectively). Western blot analysis showed decreased Nrf2 protein expression during 24-h exposure, but increased Nrf2 expression during 48 h. LonP1 protein expression increased during 24-h exposure to OTA (P < 0.05) and OTAþresveratrol (P < 0.0011) and during 48-h exposure to resveratrol (P < 0.0005).

Health Benefits of Resveratrol in Kidney Disease: Evidence from In Vitro and In Vivo Studies

“…Ochratoxin A (OTA) is a nephrotoxin that results in the destruction of renal tubular epithelium resulting in progressive renal failure, effects associated with decreased antioxidant activity and increased ROS production [91]. Treatment of HEK293 cells with RSV resulted in significantly decreased intracellular ROS production; however, when co-treated with OTA, RSV was unable to mitigate the increased ROS production (Table 4) [92]. DNA damage was decreased in HEK293 cells treated with RSV alone and co-treated with OTA, suggesting improved epithelium preservation.…”

Resveratrol and Related Stilbenoids, Nutraceutical/Dietary Complements with Health‐Promoting Actions: Industrial Production, Safety, and the Search for Mode of Action

“…Although UV light may be fungicidal, there is consensus in that RSV contributes to the decrease in ochratoxigenic burden thus acting as a defensive compound against Aspergillus action (De Rossi et al., ; Selma et al., ). These results displaying a beneficial effect of RSV were complemented by showing that it inhibited ochratoxin A toxicity also in the human HEK‐293T cell line (Raghubeer, Nagiah, Phulukdaree, & Chuturgoon, ). It should be noted that this cell line was developed from embryonic kidney and that ochratoxin A, which is a food contaminant, is nephrotoxic.…”

Nation-Based Occurrence and Endogenous Biological Reduction of Mycotoxins in Medicinal Herbs and Spices

“…However, the protective role of resveratrol against mycotoxicosis by other genotoxic mycotoxins is a controversial issue. Raghubee et al [ 68 ] found that resveratrol, a polyphenol derived from red grape, blueberries, raspberries, mulberries, peanuts and itadori, ameliorates OTA-induced cellular oxidative stress in human embryonic kidneys. In addition, aflatoxin-induced AST, ALT and SOD were reduced by resveratrol supplementation in broiler birds [ 69 ].…”